How can I encrypt and decrypt a string in C#?
如何在c#中加密和解密字符串?
23 个解决方案
#1
384
EDIT 2013-Oct: Although I've edited this answer over time to address shortcomings, please see jbtule's answer for a more robust, informed solution.
编辑2013- 10月:尽管我已经编辑了这个答案以解决缺点，请参阅jbtule的答案，以获得更健壮、更有见地的解决方案。
https://*.com/a/10366194/188474
https://*.com/a/10366194/188474
Original Answer:
最初的回答:
Here's a working example derived from the "RijndaelManaged Class" documentation and the MCTS Training Kit.
下面是一个来自“RijndaelManaged类”文档和MCTS培训包的工作示例。
EDIT 2012-April: This answer was edited to pre-pend the IV per jbtule's suggestion and as illustrated here:
编辑2012- 4月:根据jbtule的建议，这个答案被编辑为pre-pend IV，如下图所示:
http://msdn.microsoft.com/en-us/library/system.security.cryptography.aesmanaged%28v=vs.95%29.aspx
http://msdn.microsoft.com/en-us/library/system.security.cryptography.aesmanaged%28v=vs.95%29.aspx
Good luck!
好运！
public class Crypto
{
//While an app specific salt is not the best practice for
//password based encryption, it's probably safe enough as long as
//it is truly uncommon. Also too much work to alter this answer otherwise.
private static byte[] _salt = __To_Do__("Add a app specific salt here");
/// <summary>
/// Encrypt the given string using AES. The string can be decrypted using
/// DecryptStringAES(). The sharedSecret parameters must match.
/// </summary>
/// <param name="plainText">The text to encrypt.</param>
/// <param name="sharedSecret">A password used to generate a key for encryption.</param>
public static string EncryptStringAES(string plainText, string sharedSecret)
{
if (string.IsNullOrEmpty(plainText))
throw new ArgumentNullException("plainText");
if (string.IsNullOrEmpty(sharedSecret))
throw new ArgumentNullException("sharedSecret");
string outStr = null; // Encrypted string to return
RijndaelManaged aesAlg = null; // RijndaelManaged object used to encrypt the data.
try
{
// generate the key from the shared secret and the salt
Rfc2898DeriveBytes key = new Rfc2898DeriveBytes(sharedSecret, _salt);
// Create a RijndaelManaged object
aesAlg = new RijndaelManaged();
aesAlg.Key = key.GetBytes(aesAlg.KeySize / 8);
// Create a decryptor to perform the stream transform.
ICryptoTransform encryptor = aesAlg.CreateEncryptor(aesAlg.Key, aesAlg.IV);
// Create the streams used for encryption.
using (MemoryStream msEncrypt = new MemoryStream())
{
// prepend the IV
msEncrypt.Write(BitConverter.GetBytes(aesAlg.IV.Length), 0, sizeof(int));
msEncrypt.Write(aesAlg.IV, 0, aesAlg.IV.Length);
using (CryptoStream csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write))
{
using (StreamWriter swEncrypt = new StreamWriter(csEncrypt))
{
//Write all data to the stream.
swEncrypt.Write(plainText);
}
}
outStr = Convert.ToBase64String(msEncrypt.ToArray());
}
}
finally
{
// Clear the RijndaelManaged object.
if (aesAlg != null)
aesAlg.Clear();
}
// Return the encrypted bytes from the memory stream.
return outStr;
}
/// <summary>
/// Decrypt the given string. Assumes the string was encrypted using
/// EncryptStringAES(), using an identical sharedSecret.
/// </summary>
/// <param name="cipherText">The text to decrypt.</param>
/// <param name="sharedSecret">A password used to generate a key for decryption.</param>
public static string DecryptStringAES(string cipherText, string sharedSecret)
{
if (string.IsNullOrEmpty(cipherText))
throw new ArgumentNullException("cipherText");
if (string.IsNullOrEmpty(sharedSecret))
throw new ArgumentNullException("sharedSecret");
// Declare the RijndaelManaged object
// used to decrypt the data.
RijndaelManaged aesAlg = null;
// Declare the string used to hold
// the decrypted text.
string plaintext = null;
try
{
// generate the key from the shared secret and the salt
Rfc2898DeriveBytes key = new Rfc2898DeriveBytes(sharedSecret, _salt);
// Create the streams used for decryption.
byte[] bytes = Convert.FromBase64String(cipherText);
using (MemoryStream msDecrypt = new MemoryStream(bytes))
{
// Create a RijndaelManaged object
// with the specified key and IV.
aesAlg = new RijndaelManaged();
aesAlg.Key = key.GetBytes(aesAlg.KeySize / 8);
// Get the initialization vector from the encrypted stream
aesAlg.IV = ReadByteArray(msDecrypt);
// Create a decrytor to perform the stream transform.
ICryptoTransform decryptor = aesAlg.CreateDecryptor(aesAlg.Key, aesAlg.IV);
using (CryptoStream csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read))
{
using (StreamReader srDecrypt = new StreamReader(csDecrypt))
// Read the decrypted bytes from the decrypting stream
// and place them in a string.
plaintext = srDecrypt.ReadToEnd();
}
}
}
finally
{
// Clear the RijndaelManaged object.
if (aesAlg != null)
aesAlg.Clear();
}
return plaintext;
}
private static byte[] ReadByteArray(Stream s)
{
byte[] rawLength = new byte[sizeof(int)];
if (s.Read(rawLength, 0, rawLength.Length) != rawLength.Length)
{
throw new SystemException("Stream did not contain properly formatted byte array");
}
byte[] buffer = new byte[BitConverter.ToInt32(rawLength, 0)];
if (s.Read(buffer, 0, buffer.Length) != buffer.Length)
{
throw new SystemException("Did not read byte array properly");
}
return buffer;
}
}
#2
316
Modern Examples of Symmetric Authenticated Encryption of a string.
一个字符串的对称验证加密的现代示例。
The general best practice for symmetric encryption is to use Authenticated Encryption with Associated Data (AEAD), however this isn't a part of the standard .net crypto libraries. So the first example uses AES256 and then HMAC256, a two step Encrypt then MAC, which requires more overhead and more keys.
对称加密的一般最佳实践是使用经过身份验证的加密和相关数据(AEAD)，然而这并不是标准的。net加密库的一部分。第一个例子使用AES256和HMAC256，两个步骤加密然后是MAC，这需要更多的开销和更多的密钥。
The second example uses the simpler practice of AES256-GCM using the open source Bouncy Castle (via nuget).
第二个示例使用了使用开源Bouncy Castle(通过nuget)的AES256-GCM更简单的实践。
Both examples have a main function that takes secret message string, key(s) and an optional non-secret payload and return and authenticated encrypted string optionally prepended with the non-secret data. Ideally you would use these with 256bit key(s) randomly generated see NewKey().
这两个示例都有一个主函数，该函数接受秘密消息字符串、密钥和一个可选的非秘密有效负载，并返回经过身份验证的加密字符串，该字符串可选地以非秘密数据的预置。理想的情况下，您可以使用256bit密钥(s)随机生成的see NewKey()。
Both examples also have a helper methods that use a string password to generate the keys. These helper methods are provided as a convenience to match up with other examples, however they are far less secure because the strength of the password is going to be far weaker than a 256 bit key.
两个示例都有一个帮助器方法，该方法使用字符串密码生成键。这些辅助方法是为了方便与其他示例匹配而提供的，但是它们的安全性要差得多，因为密码的强度要比256位密钥弱得多。
Update: Added byte[] overloads, and only the Gist has the full formatting with 4 spaces indent and api docs due to * answer limits.
更新:添加了byte[]重载，由于*的答案限制，只有Gist有4个空格的缩进和api文档的完整格式。
.NET Built-in Encrypt(AES)-Then-MAC(HMAC) [Gist]
net内置加密(AES)-Then-MAC(HMAC)(要点)
/*
* This work (Modern Encryption of a String C#, by James Tuley),
* identified by James Tuley, is free of known copyright restrictions.
* https://gist.github.com/4336842
* http://creativecommons.org/publicdomain/mark/1.0/
*/
using System;
using System.IO;
using System.Security.Cryptography;
using System.Text;
namespace Encryption
{
public static class AESThenHMAC
{
private static readonly RandomNumberGenerator Random = RandomNumberGenerator.Create();
//Preconfigured Encryption Parameters
public static readonly int BlockBitSize = 128;
public static readonly int KeyBitSize = 256;
//Preconfigured Password Key Derivation Parameters
public static readonly int SaltBitSize = 64;
public static readonly int Iterations = 10000;
public static readonly int MinPasswordLength = 12;
/// <summary>
/// Helper that generates a random key on each call.
/// </summary>
/// <returns></returns>
public static byte[] NewKey()
{
var key = new byte[KeyBitSize / 8];
Random.GetBytes(key);
return key;
}
/// <summary>
/// Simple Encryption (AES) then Authentication (HMAC) for a UTF8 Message.
/// </summary>
/// <param name="secretMessage">The secret message.</param>
/// <param name="cryptKey">The crypt key.</param>
/// <param name="authKey">The auth key.</param>
/// <param name="nonSecretPayload">(Optional) Non-Secret Payload.</param>
/// <returns>
/// Encrypted Message
/// </returns>
/// <exception cref="System.ArgumentException">Secret Message Required!;secretMessage</exception>
/// <remarks>
/// Adds overhead of (Optional-Payload + BlockSize(16) + Message-Padded-To-Blocksize + HMac-Tag(32)) * 1.33 Base64
/// </remarks>
public static string SimpleEncrypt(string secretMessage, byte[] cryptKey, byte[] authKey,
byte[] nonSecretPayload = null)
{
if (string.IsNullOrEmpty(secretMessage))
throw new ArgumentException("Secret Message Required!", "secretMessage");
var plainText = Encoding.UTF8.GetBytes(secretMessage);
var cipherText = SimpleEncrypt(plainText, cryptKey, authKey, nonSecretPayload);
return Convert.ToBase64String(cipherText);
}
/// <summary>
/// Simple Authentication (HMAC) then Decryption (AES) for a secrets UTF8 Message.
/// </summary>
/// <param name="encryptedMessage">The encrypted message.</param>
/// <param name="cryptKey">The crypt key.</param>
/// <param name="authKey">The auth key.</param>
/// <param name="nonSecretPayloadLength">Length of the non secret payload.</param>
/// <returns>
/// Decrypted Message
/// </returns>
/// <exception cref="System.ArgumentException">Encrypted Message Required!;encryptedMessage</exception>
public static string SimpleDecrypt(string encryptedMessage, byte[] cryptKey, byte[] authKey,
int nonSecretPayloadLength = 0)
{
if (string.IsNullOrWhiteSpace(encryptedMessage))
throw new ArgumentException("Encrypted Message Required!", "encryptedMessage");
var cipherText = Convert.FromBase64String(encryptedMessage);
var plainText = SimpleDecrypt(cipherText, cryptKey, authKey, nonSecretPayloadLength);
return plainText == null ? null : Encoding.UTF8.GetString(plainText);
}
/// <summary>
/// Simple Encryption (AES) then Authentication (HMAC) of a UTF8 message
/// using Keys derived from a Password (PBKDF2).
/// </summary>
/// <param name="secretMessage">The secret message.</param>
/// <param name="password">The password.</param>
/// <param name="nonSecretPayload">The non secret payload.</param>
/// <returns>
/// Encrypted Message
/// </returns>
/// <exception cref="System.ArgumentException">password</exception>
/// <remarks>
/// Significantly less secure than using random binary keys.
/// Adds additional non secret payload for key generation parameters.
/// </remarks>
public static string SimpleEncryptWithPassword(string secretMessage, string password,
byte[] nonSecretPayload = null)
{
if (string.IsNullOrEmpty(secretMessage))
throw new ArgumentException("Secret Message Required!", "secretMessage");
var plainText = Encoding.UTF8.GetBytes(secretMessage);
var cipherText = SimpleEncryptWithPassword(plainText, password, nonSecretPayload);
return Convert.ToBase64String(cipherText);
}
/// <summary>
/// Simple Authentication (HMAC) and then Descryption (AES) of a UTF8 Message
/// using keys derived from a password (PBKDF2).
/// </summary>
/// <param name="encryptedMessage">The encrypted message.</param>
/// <param name="password">The password.</param>
/// <param name="nonSecretPayloadLength">Length of the non secret payload.</param>
/// <returns>
/// Decrypted Message
/// </returns>
/// <exception cref="System.ArgumentException">Encrypted Message Required!;encryptedMessage</exception>
/// <remarks>
/// Significantly less secure than using random binary keys.
/// </remarks>
public static string SimpleDecryptWithPassword(string encryptedMessage, string password,
int nonSecretPayloadLength = 0)
{
if (string.IsNullOrWhiteSpace(encryptedMessage))
throw new ArgumentException("Encrypted Message Required!", "encryptedMessage");
var cipherText = Convert.FromBase64String(encryptedMessage);
var plainText = SimpleDecryptWithPassword(cipherText, password, nonSecretPayloadLength);
return plainText == null ? null : Encoding.UTF8.GetString(plainText);
}
public static byte[] SimpleEncrypt(byte[] secretMessage, byte[] cryptKey, byte[] authKey, byte[] nonSecretPayload = null)
{
//User Error Checks
if (cryptKey == null || cryptKey.Length != KeyBitSize / 8)
throw new ArgumentException(String.Format("Key needs to be {0} bit!", KeyBitSize), "cryptKey");
if (authKey == null || authKey.Length != KeyBitSize / 8)
throw new ArgumentException(String.Format("Key needs to be {0} bit!", KeyBitSize), "authKey");
if (secretMessage == null || secretMessage.Length < 1)
throw new ArgumentException("Secret Message Required!", "secretMessage");
//non-secret payload optional
nonSecretPayload = nonSecretPayload ?? new byte[] { };
byte[] cipherText;
byte[] iv;
using (var aes = new AesManaged
{
KeySize = KeyBitSize,
BlockSize = BlockBitSize,
Mode = CipherMode.CBC,
Padding = PaddingMode.PKCS7
})
{
//Use random IV
aes.GenerateIV();
iv = aes.IV;
using (var encrypter = aes.CreateEncryptor(cryptKey, iv))
using (var cipherStream = new MemoryStream())
{
using (var cryptoStream = new CryptoStream(cipherStream, encrypter, CryptoStreamMode.Write))
using (var binaryWriter = new BinaryWriter(cryptoStream))
{
//Encrypt Data
binaryWriter.Write(secretMessage);
}
cipherText = cipherStream.ToArray();
}
}
//Assemble encrypted message and add authentication
using (var hmac = new HMACSHA256(authKey))
using (var encryptedStream = new MemoryStream())
{
using (var binaryWriter = new BinaryWriter(encryptedStream))
{
//Prepend non-secret payload if any
binaryWriter.Write(nonSecretPayload);
//Prepend IV
binaryWriter.Write(iv);
//Write Ciphertext
binaryWriter.Write(cipherText);
binaryWriter.Flush();
//Authenticate all data
var tag = hmac.ComputeHash(encryptedStream.ToArray());
//Postpend tag
binaryWriter.Write(tag);
}
return encryptedStream.ToArray();
}
}
public static byte[] SimpleDecrypt(byte[] encryptedMessage, byte[] cryptKey, byte[] authKey, int nonSecretPayloadLength = 0)
{
//Basic Usage Error Checks
if (cryptKey == null || cryptKey.Length != KeyBitSize / 8)
throw new ArgumentException(String.Format("CryptKey needs to be {0} bit!", KeyBitSize), "cryptKey");
if (authKey == null || authKey.Length != KeyBitSize / 8)
throw new ArgumentException(String.Format("AuthKey needs to be {0} bit!", KeyBitSize), "authKey");
if (encryptedMessage == null || encryptedMessage.Length == 0)
throw new ArgumentException("Encrypted Message Required!", "encryptedMessage");
using (var hmac = new HMACSHA256(authKey))
{
var sentTag = new byte[hmac.HashSize / 8];
//Calculate Tag
var calcTag = hmac.ComputeHash(encryptedMessage, 0, encryptedMessage.Length - sentTag.Length);
var ivLength = (BlockBitSize / 8);
//if message length is to small just return null
if (encryptedMessage.Length < sentTag.Length + nonSecretPayloadLength + ivLength)
return null;
//Grab Sent Tag
Array.Copy(encryptedMessage, encryptedMessage.Length - sentTag.Length, sentTag, 0, sentTag.Length);
//Compare Tag with constant time comparison
var compare = 0;
for (var i = 0; i < sentTag.Length; i++)
compare |= sentTag[i] ^ calcTag[i];
//if message doesn't authenticate return null
if (compare != 0)
return null;
using (var aes = new AesManaged
{
KeySize = KeyBitSize,
BlockSize = BlockBitSize,
Mode = CipherMode.CBC,
Padding = PaddingMode.PKCS7
})
{
//Grab IV from message
var iv = new byte[ivLength];
Array.Copy(encryptedMessage, nonSecretPayloadLength, iv, 0, iv.Length);
using (var decrypter = aes.CreateDecryptor(cryptKey, iv))
using (var plainTextStream = new MemoryStream())
{
using (var decrypterStream = new CryptoStream(plainTextStream, decrypter, CryptoStreamMode.Write))
using (var binaryWriter = new BinaryWriter(decrypterStream))
{
//Decrypt Cipher Text from Message
binaryWriter.Write(
encryptedMessage,
nonSecretPayloadLength + iv.Length,
encryptedMessage.Length - nonSecretPayloadLength - iv.Length - sentTag.Length
);
}
//Return Plain Text
return plainTextStream.ToArray();
}
}
}
}
public static byte[] SimpleEncryptWithPassword(byte[] secretMessage, string password, byte[] nonSecretPayload = null)
{
nonSecretPayload = nonSecretPayload ?? new byte[] {};
//User Error Checks
if (string.IsNullOrWhiteSpace(password) || password.Length < MinPasswordLength)
throw new ArgumentException(String.Format("Must have a password of at least {0} characters!", MinPasswordLength), "password");
if (secretMessage == null || secretMessage.Length ==0)
throw new ArgumentException("Secret Message Required!", "secretMessage");
var payload = new byte[((SaltBitSize / 8) * 2) + nonSecretPayload.Length];
Array.Copy(nonSecretPayload, payload, nonSecretPayload.Length);
int payloadIndex = nonSecretPayload.Length;
byte[] cryptKey;
byte[] authKey;
//Use Random Salt to prevent pre-generated weak password attacks.
using (var generator = new Rfc2898DeriveBytes(password, SaltBitSize / 8, Iterations))
{
var salt = generator.Salt;
//Generate Keys
cryptKey = generator.GetBytes(KeyBitSize / 8);
//Create Non Secret Payload
Array.Copy(salt, 0, payload, payloadIndex, salt.Length);
payloadIndex += salt.Length;
}
//Deriving separate key, might be less efficient than using HKDF,
//but now compatible with RNEncryptor which had a very similar wireformat and requires less code than HKDF.
using (var generator = new Rfc2898DeriveBytes(password, SaltBitSize / 8, Iterations))
{
var salt = generator.Salt;
//Generate Keys
authKey = generator.GetBytes(KeyBitSize / 8);
//Create Rest of Non Secret Payload
Array.Copy(salt, 0, payload, payloadIndex, salt.Length);
}
return SimpleEncrypt(secretMessage, cryptKey, authKey, payload);
}
public static byte[] SimpleDecryptWithPassword(byte[] encryptedMessage, string password, int nonSecretPayloadLength = 0)
{
//User Error Checks
if (string.IsNullOrWhiteSpace(password) || password.Length < MinPasswordLength)
throw new ArgumentException(String.Format("Must have a password of at least {0} characters!", MinPasswordLength), "password");
if (encryptedMessage == null || encryptedMessage.Length == 0)
throw new ArgumentException("Encrypted Message Required!", "encryptedMessage");
var cryptSalt = new byte[SaltBitSize / 8];
var authSalt = new byte[SaltBitSize / 8];
//Grab Salt from Non-Secret Payload
Array.Copy(encryptedMessage, nonSecretPayloadLength, cryptSalt, 0, cryptSalt.Length);
Array.Copy(encryptedMessage, nonSecretPayloadLength + cryptSalt.Length, authSalt, 0, authSalt.Length);
byte[] cryptKey;
byte[] authKey;
//Generate crypt key
using (var generator = new Rfc2898DeriveBytes(password, cryptSalt, Iterations))
{
cryptKey = generator.GetBytes(KeyBitSize / 8);
}
//Generate auth key
using (var generator = new Rfc2898DeriveBytes(password, authSalt, Iterations))
{
authKey = generator.GetBytes(KeyBitSize / 8);
}
return SimpleDecrypt(encryptedMessage, cryptKey, authKey, cryptSalt.Length + authSalt.Length + nonSecretPayloadLength);
}
}
}
Bouncy Castle AES-GCM [Gist]
Bouncy Castle AES-GCM(要点)
/*
* This work (Modern Encryption of a String C#, by James Tuley),
* identified by James Tuley, is free of known copyright restrictions.
* https://gist.github.com/4336842
* http://creativecommons.org/publicdomain/mark/1.0/
*/
using System;
using System.IO;
using System.Text;
using Org.BouncyCastle.Crypto;
using Org.BouncyCastle.Crypto.Engines;
using Org.BouncyCastle.Crypto.Generators;
using Org.BouncyCastle.Crypto.Modes;
using Org.BouncyCastle.Crypto.Parameters;
using Org.BouncyCastle.Security;
namespace Encryption
{
public static class AESGCM
{
private static readonly SecureRandom Random = new SecureRandom();
//Preconfigured Encryption Parameters
public static readonly int NonceBitSize = 128;
public static readonly int MacBitSize = 128;
public static readonly int KeyBitSize = 256;
//Preconfigured Password Key Derivation Parameters
public static readonly int SaltBitSize = 128;
public static readonly int Iterations = 10000;
public static readonly int MinPasswordLength = 12;
/// <summary>
/// Helper that generates a random new key on each call.
/// </summary>
/// <returns></returns>
public static byte[] NewKey()
{
var key = new byte[KeyBitSize / 8];
Random.NextBytes(key);
return key;
}
/// <summary>
/// Simple Encryption And Authentication (AES-GCM) of a UTF8 string.
/// </summary>
/// <param name="secretMessage">The secret message.</param>
/// <param name="key">The key.</param>
/// <param name="nonSecretPayload">Optional non-secret payload.</param>
/// <returns>
/// Encrypted Message
/// </returns>
/// <exception cref="System.ArgumentException">Secret Message Required!;secretMessage</exception>
/// <remarks>
/// Adds overhead of (Optional-Payload + BlockSize(16) + Message + HMac-Tag(16)) * 1.33 Base64
/// </remarks>
public static string SimpleEncrypt(string secretMessage, byte[] key, byte[] nonSecretPayload = null)
{
if (string.IsNullOrEmpty(secretMessage))
throw new ArgumentException("Secret Message Required!", "secretMessage");
var plainText = Encoding.UTF8.GetBytes(secretMessage);
var cipherText = SimpleEncrypt(plainText, key, nonSecretPayload);
return Convert.ToBase64String(cipherText);
}
/// <summary>
/// Simple Decryption & Authentication (AES-GCM) of a UTF8 Message
/// </summary>
/// <param name="encryptedMessage">The encrypted message.</param>
/// <param name="key">The key.</param>
/// <param name="nonSecretPayloadLength">Length of the optional non-secret payload.</param>
/// <returns>Decrypted Message</returns>
public static string SimpleDecrypt(string encryptedMessage, byte[] key, int nonSecretPayloadLength = 0)
{
if (string.IsNullOrEmpty(encryptedMessage))
throw new ArgumentException("Encrypted Message Required!", "encryptedMessage");
var cipherText = Convert.FromBase64String(encryptedMessage);
var plainText = SimpleDecrypt(cipherText, key, nonSecretPayloadLength);
return plainText == null ? null : Encoding.UTF8.GetString(plainText);
}
/// <summary>
/// Simple Encryption And Authentication (AES-GCM) of a UTF8 String
/// using key derived from a password (PBKDF2).
/// </summary>
/// <param name="secretMessage">The secret message.</param>
/// <param name="password">The password.</param>
/// <param name="nonSecretPayload">The non secret payload.</param>
/// <returns>
/// Encrypted Message
/// </returns>
/// <remarks>
/// Significantly less secure than using random binary keys.
/// Adds additional non secret payload for key generation parameters.
/// </remarks>
public static string SimpleEncryptWithPassword(string secretMessage, string password,
byte[] nonSecretPayload = null)
{
if (string.IsNullOrEmpty(secretMessage))
throw new ArgumentException("Secret Message Required!", "secretMessage");
var plainText = Encoding.UTF8.GetBytes(secretMessage);
var cipherText = SimpleEncryptWithPassword(plainText, password, nonSecretPayload);
return Convert.ToBase64String(cipherText);
}
/// <summary>
/// Simple Decryption and Authentication (AES-GCM) of a UTF8 message
/// using a key derived from a password (PBKDF2)
/// </summary>
/// <param name="encryptedMessage">The encrypted message.</param>
/// <param name="password">The password.</param>
/// <param name="nonSecretPayloadLength">Length of the non secret payload.</param>
/// <returns>
/// Decrypted Message
/// </returns>
/// <exception cref="System.ArgumentException">Encrypted Message Required!;encryptedMessage</exception>
/// <remarks>
/// Significantly less secure than using random binary keys.
/// </remarks>
public static string SimpleDecryptWithPassword(string encryptedMessage, string password,
int nonSecretPayloadLength = 0)
{
if (string.IsNullOrWhiteSpace(encryptedMessage))
throw new ArgumentException("Encrypted Message Required!", "encryptedMessage");
var cipherText = Convert.FromBase64String(encryptedMessage);
var plainText = SimpleDecryptWithPassword(cipherText, password, nonSecretPayloadLength);
return plainText == null ? null : Encoding.UTF8.GetString(plainText);
}
public static byte[] SimpleEncrypt(byte[] secretMessage, byte[] key, byte[] nonSecretPayload = null)
{
//User Error Checks
if (key == null || key.Length != KeyBitSize / 8)
throw new ArgumentException(String.Format("Key needs to be {0} bit!", KeyBitSize), "key");
if (secretMessage == null || secretMessage.Length == 0)
throw new ArgumentException("Secret Message Required!", "secretMessage");
//Non-secret Payload Optional
nonSecretPayload = nonSecretPayload ?? new byte[] { };
//Using random nonce large enough not to repeat
var nonce = new byte[NonceBitSize / 8];
Random.NextBytes(nonce, 0, nonce.Length);
var cipher = new GcmBlockCipher(new AesFastEngine());
var parameters = new AeadParameters(new KeyParameter(key), MacBitSize, nonce, nonSecretPayload);
cipher.Init(true, parameters);
//Generate Cipher Text With Auth Tag
var cipherText = new byte[cipher.GetOutputSize(secretMessage.Length)];
var len = cipher.ProcessBytes(secretMessage, 0, secretMessage.Length, cipherText, 0);
cipher.DoFinal(cipherText, len);
//Assemble Message
using (var combinedStream = new MemoryStream())
{
using (var binaryWriter = new BinaryWriter(combinedStream))
{
//Prepend Authenticated Payload
binaryWriter.Write(nonSecretPayload);
//Prepend Nonce
binaryWriter.Write(nonce);
//Write Cipher Text
binaryWriter.Write(cipherText);
}
return combinedStream.ToArray();
}
}
public static byte[] SimpleDecrypt(byte[] encryptedMessage, byte[] key, int nonSecretPayloadLength = 0)
{
//User Error Checks
if (key == null || key.Length != KeyBitSize / 8)
throw new ArgumentException(String.Format("Key needs to be {0} bit!", KeyBitSize), "key");
if (encryptedMessage == null || encryptedMessage.Length == 0)
throw new ArgumentException("Encrypted Message Required!", "encryptedMessage");
using (var cipherStream = new MemoryStream(encryptedMessage))
using (var cipherReader = new BinaryReader(cipherStream))
{
//Grab Payload
var nonSecretPayload = cipherReader.ReadBytes(nonSecretPayloadLength);
//Grab Nonce
var nonce = cipherReader.ReadBytes(NonceBitSize / 8);
var cipher = new GcmBlockCipher(new AesFastEngine());
var parameters = new AeadParameters(new KeyParameter(key), MacBitSize, nonce, nonSecretPayload);
cipher.Init(false, parameters);
//Decrypt Cipher Text
var cipherText = cipherReader.ReadBytes(encryptedMessage.Length - nonSecretPayloadLength - nonce.Length);
var plainText = new byte[cipher.GetOutputSize(cipherText.Length)];
try
{
var len = cipher.ProcessBytes(cipherText, 0, cipherText.Length, plainText, 0);
cipher.DoFinal(plainText, len);
}
catch (InvalidCipherTextException)
{
//Return null if it doesn't authenticate
return null;
}
return plainText;
}
}
public static byte[] SimpleEncryptWithPassword(byte[] secretMessage, string password, byte[] nonSecretPayload = null)
{
nonSecretPayload = nonSecretPayload ?? new byte[] {};
//User Error Checks
if (string.IsNullOrWhiteSpace(password) || password.Length < MinPasswordLength)
throw new ArgumentException(String.Format("Must have a password of at least {0} characters!", MinPasswordLength), "password");
if (secretMessage == null || secretMessage.Length == 0)
throw new ArgumentException("Secret Message Required!", "secretMessage");
var generator = new Pkcs5S2ParametersGenerator();
//Use Random Salt to minimize pre-generated weak password attacks.
var salt = new byte[SaltBitSize / 8];
Random.NextBytes(salt);
generator.Init(
PbeParametersGenerator.Pkcs5PasswordToBytes(password.ToCharArray()),
salt,
Iterations);
//Generate Key
var key = (KeyParameter)generator.GenerateDerivedMacParameters(KeyBitSize);
//Create Full Non Secret Payload
var payload = new byte[salt.Length + nonSecretPayload.Length];
Array.Copy(nonSecretPayload, payload, nonSecretPayload.Length);
Array.Copy(salt,0, payload,nonSecretPayload.Length, salt.Length);
return SimpleEncrypt(secretMessage, key.GetKey(), payload);
}
public static byte[] SimpleDecryptWithPassword(byte[] encryptedMessage, string password, int nonSecretPayloadLength = 0)
{
//User Error Checks
if (string.IsNullOrWhiteSpace(password) || password.Length < MinPasswordLength)
throw new ArgumentException(String.Format("Must have a password of at least {0} characters!", MinPasswordLength), "password");
if (encryptedMessage == null || encryptedMessage.Length == 0)
throw new ArgumentException("Encrypted Message Required!", "encryptedMessage");
var generator = new Pkcs5S2ParametersGenerator();
//Grab Salt from Payload
var salt = new byte[SaltBitSize / 8];
Array.Copy(encryptedMessage, nonSecretPayloadLength, salt, 0, salt.Length);
generator.Init(
PbeParametersGenerator.Pkcs5PasswordToBytes(password.ToCharArray()),
salt,
Iterations);
//Generate Key
var key = (KeyParameter)generator.GenerateDerivedMacParameters(KeyBitSize);
return SimpleDecrypt(encryptedMessage, key.GetKey(), salt.Length + nonSecretPayloadLength);
}
}
}
#3
98
Here is an example using RSA.
这里有一个使用RSA的例子。
Important: There is a limit to the size of data you can encrypt with the RSA encryption, KeySize - MinimumPadding. e.g. 256 bytes (assuming 2048 bit key) - 42 bytes (min OEAP padding) = 214 bytes (max plaintext size)
重要提示:有一个限制的数据大小，你可以加密的RSA加密，密钥大小-最小填充。例如，256字节(假设2048位键)- 42字节(最小OEAP填充)= 214字节(最大纯文本大小)
Replace your_rsa_key with your RSA key.
用RSA密钥替换您的_rsa_key。
var provider = new System.Security.Cryptography.RSACryptoServiceProvider();
provider.ImportParameters(your_rsa_key);
var encryptedBytes = provider.Encrypt(
System.Text.Encoding.UTF8.GetBytes("Hello World!"), true);
string decryptedTest = System.Text.Encoding.UTF8.GetString(
provider.Decrypt(encryptedBytes, true));
For more info, visit MSDN - RSACryptoServiceProvider
有关更多信息，请访问MSDN - RSACryptoServiceProvider
#4
48
If you are using ASP.Net you can now use built in functionality in .Net 4.0 onwards.
如果您正在使用ASP。Net现在可以使用。Net 4.0中的内置功能。
System.Web.Security.MachineKey
System.Web.Security.MachineKey
.Net 4.5 has MachineKey.Protect() and MachineKey.Unprotect().
. net 4.5有machine ekey . protect()和MachineKey.Unprotect()。
.Net 4.0 has MachineKey.Encode() and MachineKey.Decode(). You should just set the MachineKeyProtection to 'All'.
. net 4.0有machine ekey . encode()和MachineKey.Decode()。你应该将机器密钥保护设置为“All”。
Outside of ASP.Net this class seems to generate a new key with every app restart so doesn't work. With a quick peek in ILSpy it looks to me like it generates its own defaults if the appropriate app.settings are missing. So you may actually be able to set it up outside ASP.Net.
在ASP。Net这个类似乎会在每个应用重新启动时生成一个新键，因此无法工作。通过快速查看ILSpy，我觉得如果适当的应用程序没有设置，它会生成自己的默认值。所以你可以把它设置在ASP.Net之外。
I haven't been able to find a non-ASP.Net equivalent outside the System.Web namespace.
我还没有找到非asp。在系统之外的净等价。网络名称空间。
#5
45
BouncyCastle is a great Crypto library for .NET, it's available as a Nuget package for install into your projects. I like it a lot more than what's currently available in the System.Security.Cryptography library. It gives you a lot more options in terms of available algorithms, and provides more modes for those algorithms.
BouncyCastle是一个很棒的. net加密库，它可以作为Nuget包安装到项目中。我喜欢它比目前在System.Security中可用的要多得多。加密库。它提供了更多可用算法的选项，并为这些算法提供了更多的模式。
This is an example of an implementation of TwoFish, which was written by Bruce Schneier (hero to all us paranoid people out there). It's a symmetric algorithm like the Rijndael (aka AES). It was one of the three finalists for the AES standard and sibling to another famous algorithm written by Bruce Schneier called BlowFish.
这是一个实现TwoFish的例子，由Bruce Schneier(我们这些偏执的人的英雄)编写。它是一种像Rijndael(又名AES)一样的对称算法。这是AES标准和兄弟姐妹的三个入围作品之一，这是布鲁斯·施奈德(Bruce Schneier)写的另一种著名的算法，名叫“BlowFish”。
First thing with bouncycastle is to create an encryptor class, this will make it easier to implement other block ciphers within the library. The following encryptor class takes in a generic argument T where T implements IBlockCipher and has a default constructor.
使用bouncycastle的第一件事是创建encryptor类，这将使在库中实现其他块密码更容易。下面的encryptor类接受通用参数T，其中T实现IBlockCipher，并具有默认构造函数。
UPDATE: Due to popular demand I have decided to implement generating a random IV as well as include an HMAC into this class. Although from a style perspective this goes against the SOLID principle of single responsibility, because of the nature of what this class does I reniged. This class will now take two generic parameters, one for the cipher and one for the digest. It automatically generates the IV using RNGCryptoServiceProvider to provide good RNG entropy, and allows you to use whatever digest algorithm you want from BouncyCastle to generate the MAC.
更新:由于流行的需求，我已经决定实现生成一个随机的IV以及包含一个HMAC到这个类中。尽管从风格的角度来看，这违背了单一责任的坚实原则，因为这门课的本质是我所认识的。这个类现在将使用两个通用参数，一个用于密码，另一个用于摘要。它使用RNGCryptoServiceProvider自动生成IV，以提供良好的RNG熵，并允许您使用从BouncyCastle获得的任何摘要算法来生成MAC。
using System;
using System.Security.Cryptography;
using System.Text;
using Org.BouncyCastle.Crypto;
using Org.BouncyCastle.Crypto.Macs;
using Org.BouncyCastle.Crypto.Modes;
using Org.BouncyCastle.Crypto.Paddings;
using Org.BouncyCastle.Crypto.Parameters;
public sealed class Encryptor<TBlockCipher, TDigest>
where TBlockCipher : IBlockCipher, new()
where TDigest : IDigest, new()
{
private Encoding encoding;
private IBlockCipher blockCipher;
private BufferedBlockCipher cipher;
private HMac mac;
private byte[] key;
public Encryptor(Encoding encoding, byte[] key, byte[] macKey)
{
this.encoding = encoding;
this.key = key;
this.Init(key, macKey, new Pkcs7Padding());
}
public Encryptor(Encoding encoding, byte[] key, byte[] macKey, IBlockCipherPadding padding)
{
this.encoding = encoding;
this.key = key;
this.Init(key, macKey, padding);
}
private void Init(byte[] key, byte[] macKey, IBlockCipherPadding padding)
{
this.blockCipher = new CbcBlockCipher(new TBlockCipher());
this.cipher = new PaddedBufferedBlockCipher(this.blockCipher, padding);
this.mac = new HMac(new TDigest());
this.mac.Init(new KeyParameter(macKey));
}
public string Encrypt(string plain)
{
return Convert.ToBase64String(EncryptBytes(plain));
}
public byte[] EncryptBytes(string plain)
{
byte[] input = this.encoding.GetBytes(plain);
var iv = this.GenerateIV();
var cipher = this.BouncyCastleCrypto(true, input, new ParametersWithIV(new KeyParameter(key), iv));
byte[] message = CombineArrays(iv, cipher);
this.mac.Reset();
this.mac.BlockUpdate(message, 0, message.Length);
byte[] digest = new byte[this.mac.GetUnderlyingDigest().GetDigestSize()];
this.mac.DoFinal(digest, 0);
var result = CombineArrays(digest, message);
return result;
}
public byte[] DecryptBytes(byte[] bytes)
{
// split the digest into component parts
var digest = new byte[this.mac.GetUnderlyingDigest().GetDigestSize()];
var message = new byte[bytes.Length - digest.Length];
var iv = new byte[this.blockCipher.GetBlockSize()];
var cipher = new byte[message.Length - iv.Length];
Buffer.BlockCopy(bytes, 0, digest, 0, digest.Length);
Buffer.BlockCopy(bytes, digest.Length, message, 0, message.Length);
if (!IsValidHMac(digest, message))
{
throw new CryptoException();
}
Buffer.BlockCopy(message, 0, iv, 0, iv.Length);
Buffer.BlockCopy(message, iv.Length, cipher, 0, cipher.Length);
byte[] result = this.BouncyCastleCrypto(false, cipher, new ParametersWithIV(new KeyParameter(key), iv));
return result;
}
public string Decrypt(byte[] bytes)
{
return this.encoding.GetString(DecryptBytes(bytes));
}
public string Decrypt(string cipher)
{
return this.Decrypt(Convert.FromBase64String(cipher));
}
private bool IsValidHMac(byte[] digest, byte[] message)
{
this.mac.Reset();
this.mac.BlockUpdate(message, 0, message.Length);
byte[] computed = new byte[this.mac.GetUnderlyingDigest().GetDigestSize()];
this.mac.DoFinal(computed, 0);
return AreEqual(digest,computed);
}
private static bool AreEqual(byte [] digest, byte[] computed)
{
if(digest.Length != computed.Length)
{
return false;
}
int result = 0;
for (int i = 0; i < digest.Length; i++)
{
// compute equality of all bytes before returning.
// helps prevent timing attacks:
// https://codahale.com/a-lesson-in-timing-attacks/
result |= digest[i] ^ computed[i];
}
return result == 0;
}
private byte[] BouncyCastleCrypto(bool forEncrypt, byte[] input, ICipherParameters parameters)
{
try
{
cipher.Init(forEncrypt, parameters);
return this.cipher.DoFinal(input);
}
catch (CryptoException)
{
throw;
}
}
private byte[] GenerateIV()
{
using (var provider = new RNGCryptoServiceProvider())
{
// 1st block
byte[] result = new byte[this.blockCipher.GetBlockSize()];
provider.GetBytes(result);
return result;
}
}
private static byte[] CombineArrays(byte[] source1, byte[] source2)
{
byte[] result = new byte[source1.Length + source2.Length];
Buffer.BlockCopy(source1, 0, result, 0, source1.Length);
Buffer.BlockCopy(source2, 0, result, source1.Length, source2.Length);
return result;
}
}
Next just call the encrypt and decrypt methods on the new class, here's the example using twofish:
接下来只需调用新类上的加密和解密方法，这里是使用twofish的示例:
var encrypt = new Encryptor<TwofishEngine, Sha1Digest>(Encoding.UTF8, key, hmacKey);
string cipher = encrypt.Encrypt("TEST");
string plainText = encrypt.Decrypt(cipher);
It's just as easy to substitute another block cipher like TripleDES:
用另一个块密码就像TripleDES一样简单:
var des = new Encryptor<DesEdeEngine, Sha1Digest>(Encoding.UTF8, key, hmacKey);
string cipher = des.Encrypt("TEST");
string plainText = des.Decrypt(cipher);
Finally if you want to use AES with SHA256 HMAC you can do the following:
最后，如果你想使用AES与SHA256 HMAC，你可以做以下:
var aes = new Encryptor<AesEngine, Sha256Digest>(Encoding.UTF8, key, hmacKey);
cipher = aes.Encrypt("TEST");
plainText = aes.Decrypt(cipher);
The hardest part about encryption actually deals with the keys and not the algorithms. You'll have to think about where you store your keys, and if you have to, how you exchange them. These algorithms have all withstood the test of time, and are extremely hard to break. Someone who wants to steal information from you isn't going to spend eternity doing cryptanalysis on your messages, they're going to try to figure out what or where your key is. So #1 choose your keys wisely, #2 store them in a safe place, if you use a web.config and IIS then you can encrypt parts of the the web.config, and finally if you have to exchange keys make sure that your protocol for exchanging the key is secure.
加密最难的部分实际上是处理密钥，而不是算法。你必须考虑你的钥匙放在哪里，如果需要的话，如何交换。这些算法都经受住了时间的考验，而且很难打破。那些想从你那里窃取信息的人不会花时间对你的信息进行密码分析，他们会试图找出你的钥匙在哪里。所以，如果你使用网络，第一点要明智地选择你的钥匙，第二点要把钥匙放在安全的地方。配置和IIS，然后您可以加密部分web。配置，最后，如果您必须交换密钥，请确保交换密钥的协议是安全的。
Update 2 Changed compare method to mitigate against timing attacks. See more info here http://codahale.com/a-lesson-in-timing-attacks/ . Also updated to default to PKCS7 padding and added new constructor to allow end user the ability to choose which padding they would like to use. Thanks @CodesInChaos for the suggestions.
更新2更改了比较方法以减少定时攻击。查看更多信息http://codahale.com/a-lesson-in- time -attacks/。还更新为默认的PKCS7填充，并添加了新的构造函数，以便最终用户能够选择他们想要使用的填充。感谢@CodesInChaos的建议。
#6
14
Disclaimer: This solution should only be used for data at rest that is not exposed to the public (for example - a configuration file or DB). Only in this scenario, the quick-and-dirty solution can be considered better than @jbtule's solution, due to lower maintanance.
免责声明:此解决方案应该只用于不公开的静态数据(例如，配置文件或DB)。只有在这种情况下，由于主色调较低，可以认为快速且肮脏的解决方案比@jbtule的解决方案要好。
Original post: I found jbtule's answer a bit complicated for a quick and dirty secured AES string encryption and Brett's answer had a bug with the Initialization Vector being a fixed value making it vulnerable to padding attacks, so I fixed Brett's code and added a random IV that is added to the chipered string, creating a different encrypted value each and every encryption of the same value:
原来的帖子:我发现jbtule的回答有点复杂的快速和肮脏的AES加密字符串和布雷特的回答有错误和初始化向量是一个固定值使其容易填充攻击,所以我固定布雷特的代码和添加了一个随机字符串添加到chipered IV,创建一个不同的加密值每加密相同的值:
Encryption:
加密:
public static string Encrypt(string clearText)
{
byte[] clearBytes = Encoding.Unicode.GetBytes(clearText);
using (Aes encryptor = Aes.Create())
{
byte[] IV = new byte[15];
rand.NextBytes(IV);
Rfc2898DeriveBytes pdb = new Rfc2898DeriveBytes(EncryptionKey, IV);
encryptor.Key = pdb.GetBytes(32);
encryptor.IV = pdb.GetBytes(16);
using (MemoryStream ms = new MemoryStream())
{
using (CryptoStream cs = new CryptoStream(ms, encryptor.CreateEncryptor(), CryptoStreamMode.Write))
{
cs.Write(clearBytes, 0, clearBytes.Length);
cs.Close();
}
clearText = Convert.ToBase64String(IV) + Convert.ToBase64String(ms.ToArray());
}
}
return clearText;
}
Decryption:
解密:
public static string Decrypt(string cipherText)
{
byte[] IV = Convert.FromBase64String(cipherText.Substring(0, 20));
cipherText = cipherText.Substring(20).Replace(" ", "+");
byte[] cipherBytes = Convert.FromBase64String(cipherText);
using (Aes encryptor = Aes.Create())
{
Rfc2898DeriveBytes pdb = new Rfc2898DeriveBytes(EncryptionKey, IV);
encryptor.Key = pdb.GetBytes(32);
encryptor.IV = pdb.GetBytes(16);
using (MemoryStream ms = new MemoryStream())
{
using (CryptoStream cs = new CryptoStream(ms, encryptor.CreateDecryptor(), CryptoStreamMode.Write))
{
cs.Write(cipherBytes, 0, cipherBytes.Length);
cs.Close();
}
cipherText = Encoding.Unicode.GetString(ms.ToArray());
}
}
return cipherText;
}
Replace EncryptionKey with your key. In my implementation, the key is being saved in the configuration file (web.config\app.config) as you shouldn't save it hard coded. The configuration file should be also encrypted so the key won't be saved as clear text in it.
用密钥替换EncryptionKey。在我的实现中，密钥被保存在配置文件(web.config\app.config)中，因为您不应该将其硬编码。配置文件也应该加密，这样密钥就不会作为明文保存在其中。
protected static string _Key = "";
protected static string EncryptionKey
{
get
{
if (String.IsNullOrEmpty(_Key))
{
_Key = ConfigurationManager.AppSettings["AESKey"].ToString();
}
return _Key;
}
}
#7
10
Encryption
加密
public string EncryptString(string inputString)
{
MemoryStream memStream = null;
try
{
byte[] key = { };
byte[] IV = { 12, 21, 43, 17, 57, 35, 67, 27 };
string encryptKey = "aXb2uy4z"; // MUST be 8 characters
key = Encoding.UTF8.GetBytes(encryptKey);
byte[] byteInput = Encoding.UTF8.GetBytes(inputString);
DESCryptoServiceProvider provider = new DESCryptoServiceProvider();
memStream = new MemoryStream();
ICryptoTransform transform = provider.CreateEncryptor(key, IV);
CryptoStream cryptoStream = new CryptoStream(memStream, transform, CryptoStreamMode.Write);
cryptoStream.Write(byteInput, 0, byteInput.Length);
cryptoStream.FlushFinalBlock();
}
catch (Exception ex)
{
Response.Write(ex.Message);
}
return Convert.ToBase64String(memStream.ToArray());
}
Decryption:
解密:
public string DecryptString(string inputString)
{
MemoryStream memStream = null;
try
{
byte[] key = { };
byte[] IV = { 12, 21, 43, 17, 57, 35, 67, 27 };
string encryptKey = "aXb2uy4z"; // MUST be 8 characters
key = Encoding.UTF8.GetBytes(encryptKey);
byte[] byteInput = new byte[inputString.Length];
byteInput = Convert.FromBase64String(inputString);
DESCryptoServiceProvider provider = new DESCryptoServiceProvider();
memStream = new MemoryStream();
ICryptoTransform transform = provider.CreateDecryptor(key, IV);
CryptoStream cryptoStream = new CryptoStream(memStream, transform, CryptoStreamMode.Write);
cryptoStream.Write(byteInput, 0, byteInput.Length);
cryptoStream.FlushFinalBlock();
}
catch (Exception ex)
{
Response.Write(ex.Message);
}
Encoding encoding1 = Encoding.UTF8;
return encoding1.GetString(memStream.ToArray());
}
#8
5
With the reference of Encrypt and Decrypt a String in c#, I found one of good solution :
参考c#中对字符串的加密和解密，我找到了一个很好的解决方案:
static readonly string PasswordHash = "P@@Sw0rd";
static readonly string SaltKey = "S@LT&KEY";
static readonly string VIKey = "@1B2c3D4e5F6g7H8";
For Encrypt
对于加密
public static string Encrypt(string plainText)
{
byte[] plainTextBytes = Encoding.UTF8.GetBytes(plainText);
byte[] keyBytes = new Rfc2898DeriveBytes(PasswordHash, Encoding.ASCII.GetBytes(SaltKey)).GetBytes(256 / 8);
var symmetricKey = new RijndaelManaged() { Mode = CipherMode.CBC, Padding = PaddingMode.Zeros };
var encryptor = symmetricKey.CreateEncryptor(keyBytes, Encoding.ASCII.GetBytes(VIKey));
byte[] cipherTextBytes;
using (var memoryStream = new MemoryStream())
{
using (var cryptoStream = new CryptoStream(memoryStream, encryptor, CryptoStreamMode.Write))
{
cryptoStream.Write(plainTextBytes, 0, plainTextBytes.Length);
cryptoStream.FlushFinalBlock();
cipherTextBytes = memoryStream.ToArray();
cryptoStream.Close();
}
memoryStream.Close();
}
return Convert.ToBase64String(cipherTextBytes);
}
For Decrypt
对解密
public static string Decrypt(string encryptedText)
{
byte[] cipherTextBytes = Convert.FromBase64String(encryptedText);
byte[] keyBytes = new Rfc2898DeriveBytes(PasswordHash, Encoding.ASCII.GetBytes(SaltKey)).GetBytes(256 / 8);
var symmetricKey = new RijndaelManaged() { Mode = CipherMode.CBC, Padding = PaddingMode.None };
var decryptor = symmetricKey.CreateDecryptor(keyBytes, Encoding.ASCII.GetBytes(VIKey));
var memoryStream = new MemoryStream(cipherTextBytes);
var cryptoStream = new CryptoStream(memoryStream, decryptor, CryptoStreamMode.Read);
byte[] plainTextBytes = new byte[cipherTextBytes.Length];
int decryptedByteCount = cryptoStream.Read(plainTextBytes, 0, plainTextBytes.Length);
memoryStream.Close();
cryptoStream.Close();
return Encoding.UTF8.GetString(plainTextBytes, 0, decryptedByteCount).TrimEnd("\0".ToCharArray());
}
#9
4
To support mattmanser answer. Here's an example using MachineKey class to encrypt/decrypt URL safe values.
支持mattmanser回答。这里有一个使用MachineKey类加密/解密URL安全值的示例。
Something to bear in mind, as mentioned before, this will use Machine config settings (https://msdn.microsoft.com/en-us/library/ff649308.aspx). You can set encryption and decryption key/algorithm manually (you might need this specially if your site is running on multiple servers) in web.config file. You can generate keys from IIS (see here: https://blogs.msdn.microsoft.com/vijaysk/2009/05/13/iis-7-tip-10-you-can-generate-machine-keys-from-the-iis-manager/) or can use an online machine key generator like: http://www.developerfusion.com/tools/generatemachinekey/
请记住，如前所述，这将使用机器配置设置(https://msdn.microsoft.com/en-us/library/ff649308.aspx)。您可以在web中手动设置加密和解密密钥/算法(如果您的站点在多个服务器上运行，您可能尤其需要这个)。配置文件。您可以从IIS生成密钥(参见这里:https://blogs.msdn.microsoft.com/vijaysk/2009/05/13/iis-7-tip-10- can-generate-machine- keys-fromiismanager/)，也可以使用在线机器密钥生成器，如:http://www.developerfusion.com/tools/generatemachinekey/
private static readonly UTF8Encoding Encoder = new UTF8Encoding();
public static string Encrypt(string unencrypted)
{
if (string.IsNullOrEmpty(unencrypted))
return string.Empty;
try
{
var encryptedBytes = MachineKey.Protect(Encoder.GetBytes(unencrypted));
if (encryptedBytes != null && encryptedBytes.Length > 0)
return HttpServerUtility.UrlTokenEncode(encryptedBytes);
}
catch (Exception)
{
return string.Empty;
}
return string.Empty;
}
public static string Decrypt(string encrypted)
{
if (string.IsNullOrEmpty(encrypted))
return string.Empty;
try
{
var bytes = HttpServerUtility.UrlTokenDecode(encrypted);
if (bytes != null && bytes.Length > 0)
{
var decryptedBytes = MachineKey.Unprotect(bytes);
if(decryptedBytes != null && decryptedBytes.Length > 0)
return Encoder.GetString(decryptedBytes);
}
}
catch (Exception)
{
return string.Empty;
}
return string.Empty;
}
#10
3
Here is a simple example of encrypting strings in C# using AES CBC mode with random IV and HMAC and password-derived keys, to show the basic moving parts:
这里有一个简单的例子，它使用AES CBC模式，使用AES CBC模式，使用随机的IV和HMAC和密码派生的密钥对字符串进行加密，以显示基本的移动部分:
private byte[] EncryptBytes(byte[] key, byte[] plaintext)
{
using (var cipher = new RijndaelManaged { Key = key })
{
using (var encryptor = cipher.CreateEncryptor())
{
var ciphertext = encryptor.TransformFinalBlock(plaintext, 0, plaintext.Length);
// IV is prepended to ciphertext
return cipher.IV.Concat(ciphertext).ToArray();
}
}
}
private byte[] DecryptBytes(byte[] key, byte[] packed)
{
using (var cipher = new RijndaelManaged { Key = key })
{
int ivSize = cipher.BlockSize / 8;
cipher.IV = packed.Take(ivSize).ToArray();
using (var encryptor = cipher.CreateDecryptor())
{
return encryptor.TransformFinalBlock(packed, ivSize, packed.Length - ivSize);
}
}
}
private byte[] AddMac(byte[] key, byte[] data)
{
using (var hmac = new HMACSHA256(key))
{
var macBytes = hmac.ComputeHash(data);
// HMAC is appended to data
return data.Concat(macBytes).ToArray();
}
}
private bool BadMac(byte[] found, byte[] computed)
{
int mismatch = 0;
// Aim for consistent timing regardless of inputs
for (int i = 0; i < found.Length; i++)
{
mismatch += found[i] == computed[i] ? 0 : 1;
}
return mismatch != 0;
}
private byte[] RemoveMac(byte[] key, byte[] data)
{
using (var hmac = new HMACSHA256(key))
{
int macSize = hmac.HashSize / 8;
var packed = data.Take(data.Length - macSize).ToArray();
var foundMac = data.Skip(packed.Length).ToArray();
var computedMac = hmac.ComputeHash(packed);
if (this.BadMac(foundMac, computedMac))
{
throw new Exception("Bad MAC");
}
return packed;
}
}
private List<byte[]> DeriveTwoKeys(string password)
{
var salt = new byte[] { 1, 2, 3, 4, 5, 6, 7, 8 };
var kdf = new Rfc2898DeriveBytes(password, salt, 10000);
var bytes = kdf.GetBytes(32); // Two keys 128 bits each
return new List<byte[]> { bytes.Take(16).ToArray(), bytes.Skip(16).ToArray() };
}
public byte[] EncryptString(string password, String message)
{
var keys = this.DeriveTwoKeys(password);
var plaintext = Encoding.UTF8.GetBytes(message);
var packed = this.EncryptBytes(keys[0], plaintext);
return this.AddMac(keys[1], packed);
}
public String DecryptString(string password, byte[] secret)
{
var keys = this.DeriveTwoKeys(password);
var packed = this.RemoveMac(keys[1], secret);
var plaintext = this.DecryptBytes(keys[0], packed);
return Encoding.UTF8.GetString(plaintext);
}
public void Example()
{
var password = "correcthorsebatterystaple";
var secret = this.EncryptString(password, "Hello World");
Console.WriteLine("secret: " + BitConverter.ToString(secret));
var recovered = this.DecryptString(password, secret);
Console.WriteLine(recovered);
}
#11
3
If you got here looking for PGP encryption, in the following comment on an example of how to use PGP encryption via BouncyCastle, the PGPEncryptDecrypt class seems to work basically out of the box:
如果您在这里寻找PGP加密，以下是关于如何通过BouncyCastle使用PGP加密的示例的评论，那么PGPEncryptDecrypt类似乎基本上是开箱即用的:
http://blogs.microsoft.co.il/kim/2009/01/23/pgp-zip-encrypted-files-with-c/#comment-611002
http://blogs.microsoft.co.il/kim/2009/01/23/pgp-zip-encrypted-files-with-c/评论- 611002
Too long to paste here, slightly modified: https://gist.github.com/zaus/c0ea1fd8dad5d9590af1
在这里粘贴太长了，稍微修改一下:https://gist.github.com/zaus/c0ea1fd8dad5d9590af1
#12
3
An alternative to BouncyCastle for AES-GCM encryption is libsodium-net. It wraps the libsodium C library. One nice advantage is that it uses the AES-NI extension in CPUs for very fast encryption. The down side is that it won't work at all if the CPU doesn't have the extension. There's no software fall back.
用于AES-GCM加密的BouncyCastle的另一种选择是libsodium-net。它封装了lib钠C库。一个很好的优点是它使用cpu中的AES-NI扩展来进行非常快速的加密。缺点是，如果CPU没有扩展，它根本就不能工作。没有软件可以退回。
#13
2
This is the class that was placed here by Brett. However I made a slight edit since I was receiving the error 'Invalid length for a Base-64 char array' when using it for URL strings to encrypt and decrypt.
这是布雷特布置的课程。然而，我做了一个轻微的编辑，因为我在使用URL字符串加密和解密时收到了错误“Base-64 char数组的无效长度”。
public class CryptoURL
{
private static byte[] _salt = Encoding.ASCII.GetBytes("Catto_Salt_Enter_Any_Value99");
/// <summary>
/// Encrypt the given string using AES. The string can be decrypted using
/// DecryptStringAES(). The sharedSecret parameters must match.
/// The SharedSecret for the Password Reset that is used is in the next line
/// string sharedSecret = "OneUpSharedSecret9";
/// </summary>
/// <param name="plainText">The text to encrypt.</param>
/// <param name="sharedSecret">A password used to generate a key for encryption.</param>
public static string EncryptString(string plainText, string sharedSecret)
{
if (string.IsNullOrEmpty(plainText))
throw new ArgumentNullException("plainText");
if (string.IsNullOrEmpty(sharedSecret))
throw new ArgumentNullException("sharedSecret");
string outStr = null; // Encrypted string to return
RijndaelManaged aesAlg = null; // RijndaelManaged object used to encrypt the data.
try
{
// generate the key from the shared secret and the salt
Rfc2898DeriveBytes key = new Rfc2898DeriveBytes(sharedSecret, _salt);
// Create a RijndaelManaged object
aesAlg = new RijndaelManaged();
aesAlg.Key = key.GetBytes(aesAlg.KeySize / 8);
// Create a decryptor to perform the stream transform.
ICryptoTransform encryptor = aesAlg.CreateEncryptor(aesAlg.Key, aesAlg.IV);
// Create the streams used for encryption.
using (MemoryStream msEncrypt = new MemoryStream())
{
// prepend the IV
msEncrypt.Write(BitConverter.GetBytes(aesAlg.IV.Length), 0, sizeof(int));
msEncrypt.Write(aesAlg.IV, 0, aesAlg.IV.Length);
using (CryptoStream csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write))
{
using (StreamWriter swEncrypt = new StreamWriter(csEncrypt))
{
//Write all data to the stream.
swEncrypt.Write(plainText);
}
}
outStr = HttpServerUtility.UrlTokenEncode(msEncrypt.ToArray());
//outStr = Convert.ToBase64String(msEncrypt.ToArray());
// you may need to add a reference. right click reference in solution explorer => "add Reference" => .NET tab => select "System.Web"
}
}
finally
{
// Clear the RijndaelManaged object.
if (aesAlg != null)
aesAlg.Clear();
}
// Return the encrypted bytes from the memory stream.
return outStr;
}
/// <summary>
/// Decrypt the given string. Assumes the string was encrypted using
/// EncryptStringAES(), using an identical sharedSecret.
/// </summary>
/// <param name="cipherText">The text to decrypt.</param>
/// <param name="sharedSecret">A password used to generate a key for decryption.</param>
public static string DecryptString(string cipherText, string sharedSecret)
{
if (string.IsNullOrEmpty(cipherText))
throw new ArgumentNullException("cipherText");
if (string.IsNullOrEmpty(sharedSecret))
throw new ArgumentNullException("sharedSecret");
// Declare the RijndaelManaged object
// used to decrypt the data.
RijndaelManaged aesAlg = null;
// Declare the string used to hold
// the decrypted text.
string plaintext = null;
byte[] inputByteArray;
try
{
// generate the key from the shared secret and the salt
Rfc2898DeriveBytes key = new Rfc2898DeriveBytes(sharedSecret, _salt);
// Create the streams used for decryption.
//byte[] bytes = Convert.FromBase64String(cipherText);
inputByteArray = HttpServerUtility.UrlTokenDecode(cipherText);
using (MemoryStream msDecrypt = new MemoryStream(inputByteArray))
{
// Create a RijndaelManaged object
// with the specified key and IV.
aesAlg = new RijndaelManaged();
aesAlg.Key = key.GetBytes(aesAlg.KeySize / 8);
// Get the initialization vector from the encrypted stream
aesAlg.IV = ReadByteArray(msDecrypt);
// Create a decrytor to perform the stream transform.
ICryptoTransform decryptor = aesAlg.CreateDecryptor(aesAlg.Key, aesAlg.IV);
using (CryptoStream csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read))
{
using (StreamReader srDecrypt = new StreamReader(csDecrypt))
// Read the decrypted bytes from the decrypting stream
// and place them in a string.
plaintext = srDecrypt.ReadToEnd();
}
}
}
catch (System.Exception ex)
{
return "ERROR";
//throw ex;
}
finally
{
// Clear the RijndaelManaged object.
if (aesAlg != null)
aesAlg.Clear();
}
return plaintext;
}
static string ConvertStringArrayToString(string[] array)
{
//
// Concatenate all the elements into a StringBuilder.
//
StringBuilder builder = new StringBuilder();
foreach (string value in array)
{
builder.Append(value);
builder.Append('.');
}
return builder.ToString();
}
private static byte[] ReadByteArray(Stream s)
{
byte[] rawLength = new byte[sizeof(int)];
if (s.Read(rawLength, 0, rawLength.Length) != rawLength.Length)
{
throw new SystemException("Stream did not contain properly formatted byte array");
}
byte[] buffer = new byte[BitConverter.ToInt32(rawLength, 0)];
if (s.Read(buffer, 0, buffer.Length) != buffer.Length)
{
throw new SystemException("Did not read byte array properly");
}
return buffer;
}
}
#14
1
Encryption is a very common matter in programming. I think it is better to install a package to do the task for you. Maybe a simple open source Nuget project like Simple Aes Encryption
加密是编程中很常见的事情。我认为最好是安装一个包来帮你完成这个任务。也许是一个简单的开源Nuget项目，比如简单的Aes加密
The key is in the config file and therefore it is easy to change in the production environment, and I don't see any drawbacks
关键是在配置文件中，因此很容易在生产环境中更改，我没有看到任何缺陷
<MessageEncryption>
<EncryptionKey KeySize="256" Key="3q2+796tvu/erb7v3q2+796tvu/erb7v3q2+796tvu8="/>
</MessageEncryption>
#15
0
Copied in my answer here from a similar question: Simple two-way encryption for C#.
我在这里的答案来自一个类似的问题:c#的简单双向加密。
Based on multiple answers and comments.
基于多个答案和评论。
- Random initialization vector prepended to crypto text (@jbtule)
- 随机初始化向量预置到加密文本(@jbtule)
- Use TransformFinalBlock() instead of MemoryStream (@RenniePet)
- 使用TransformFinalBlock()而不是MemoryStream (@RenniePet)
- No pre-filled keys to avoid anyone copy & pasting a disaster
- 没有预先填充的键可以避免任何人复制粘贴灾难
- Proper dispose and using patterns
- 正确的配置和使用模式
Code:
代码:
/// <summary>
/// Simple encryption/decryption using a random initialization vector
/// and prepending it to the crypto text.
/// </summary>
/// <remarks>Based on multiple answers in https://*.com/questions/165808/simple-two-way-encryption-for-c-sharp </remarks>
public class SimpleAes : IDisposable
{
/// <summary>
/// Initialization vector length in bytes.
/// </summary>
private const int IvBytes = 16;
/// <summary>
/// Must be exactly 16, 24 or 32 characters long.
/// </summary>
private static readonly byte[] Key = Convert.FromBase64String("FILL ME WITH 16, 24 OR 32 CHARS");
private readonly UTF8Encoding _encoder;
private readonly ICryptoTransform _encryptor;
private readonly RijndaelManaged _rijndael;
public SimpleAes()
{
_rijndael = new RijndaelManaged {Key = Key};
_rijndael.GenerateIV();
_encryptor = _rijndael.CreateEncryptor();
_encoder = new UTF8Encoding();
}
public string Decrypt(string encrypted)
{
return _encoder.GetString(Decrypt(Convert.FromBase64String(encrypted)));
}
public void Dispose()
{
_rijndael.Dispose();
_encryptor.Dispose();
}
public string Encrypt(string unencrypted)
{
return Convert.ToBase64String(Encrypt(_encoder.GetBytes(unencrypted)));
}
private byte[] Decrypt(byte[] buffer)
{
// IV is prepended to cryptotext
byte[] iv = buffer.Take(IvBytes).ToArray();
using (ICryptoTransform decryptor = _rijndael.CreateDecryptor(_rijndael.Key, iv))
{
return decryptor.TransformFinalBlock(buffer, IvBytes, buffer.Length - IvBytes);
}
}
private byte[] Encrypt(byte[] buffer)
{
// Prepend cryptotext with IV
byte[] inputBuffer = _rijndael.IV.Concat(buffer).ToArray();
return _encryptor.TransformFinalBlock(inputBuffer, IvBytes, buffer.Length);
}
}
#16
0
Here is simple Snippet originally by ASP Snippets
以下是最初由ASP片段组成的简单代码片段
using System.Text;
using System.Security.Cryptography;
using System.IO;
private string Encrypt(string clearText)
{
string EncryptionKey = "yourkey";
byte[] clearBytes = Encoding.Unicode.GetBytes(clearText);
using (Aes encryptor = Aes.Create())
{
Rfc2898DeriveBytes pdb = new Rfc2898DeriveBytes(EncryptionKey, new byte[] { 0x49, 0x76, 0x61, 0x6e, 0x20, 0x4d, 0x65, 0x64, 0x76, 0x65, 0x64, 0x65, 0x76 });
encryptor.Key = pdb.GetBytes(32);
encryptor.IV = pdb.GetBytes(16);
using (MemoryStream ms = new MemoryStream())
{
using (CryptoStream cs = new CryptoStream(ms, encryptor.CreateEncryptor(), CryptoStreamMode.Write))
{
cs.Write(clearBytes, 0, clearBytes.Length);
cs.Close();
}
clearText = Convert.ToBase64String(ms.ToArray());
}
}
return clearText;
}
private string Decrypt(string cipherText)
{
string EncryptionKey = "yourkey";
cipherText = cipherText.Replace(" ", "+");
byte[] cipherBytes = Convert.FromBase64String(cipherText);
using (Aes encryptor = Aes.Create())
{
Rfc2898DeriveBytes pdb = new Rfc2898DeriveBytes(EncryptionKey, new byte[] { 0x49, 0x76, 0x61, 0x6e, 0x20, 0x4d, 0x65, 0x64, 0x76, 0x65, 0x64, 0x65, 0x76 });
encryptor.Key = pdb.GetBytes(32);
encryptor.IV = pdb.GetBytes(16);
using (MemoryStream ms = new MemoryStream())
{
using (CryptoStream cs = new CryptoStream(ms, encryptor.CreateDecryptor(), CryptoStreamMode.Write))
{
cs.Write(cipherBytes, 0, cipherBytes.Length);
cs.Close();
}
cipherText = Encoding.Unicode.GetString(ms.ToArray());
}
}
return cipherText;
}
#17
0
AES Algorithm:
AES算法:
public static class CryptographyProvider
{
public static string EncryptString(string plainText, out string Key)
{
if (plainText == null || plainText.Length <= 0)
throw new ArgumentNullException("plainText");
using (Aes _aesAlg = Aes.Create())
{
Key = Convert.ToBase64String(_aesAlg.Key);
ICryptoTransform _encryptor = _aesAlg.CreateEncryptor(_aesAlg.Key, _aesAlg.IV);
using (MemoryStream _memoryStream = new MemoryStream())
{
_memoryStream.Write(_aesAlg.IV, 0, 16);
using (CryptoStream _cryptoStream = new CryptoStream(_memoryStream, _encryptor, CryptoStreamMode.Write))
{
using (StreamWriter _streamWriter = new StreamWriter(_cryptoStream))
{
_streamWriter.Write(plainText);
}
return Convert.ToBase64String(_memoryStream.ToArray());
}
}
}
}
public static string DecryptString(string cipherText, string Key)
{
if (string.IsNullOrEmpty(cipherText))
throw new ArgumentNullException("cipherText");
if (string.IsNullOrEmpty(Key))
throw new ArgumentNullException("Key");
string plaintext = null;
byte[] _initialVector = new byte[16];
byte[] _Key = Convert.FromBase64String(Key);
byte[] _cipherTextBytesArray = Convert.FromBase64String(cipherText);
byte[] _originalString = new byte[_cipherTextBytesArray.Length - 16];
Array.Copy(_cipherTextBytesArray, 0, _initialVector, 0, _initialVector.Length);
Array.Copy(_cipherTextBytesArray, 16, _originalString, 0, _cipherTextBytesArray.Length - 16);
using (Aes _aesAlg = Aes.Create())
{
_aesAlg.Key = _Key;
_aesAlg.IV = _initialVector;
ICryptoTransform decryptor = _aesAlg.CreateDecryptor(_aesAlg.Key, _aesAlg.IV);
using (MemoryStream _memoryStream = new MemoryStream(_originalString))
{
using (CryptoStream _cryptoStream = new CryptoStream(_memoryStream, decryptor, CryptoStreamMode.Read))
{
using (StreamReader _streamReader = new StreamReader(_cryptoStream))
{
plaintext = _streamReader.ReadToEnd();
}
}
}
}
return plaintext;
}
}
#18
-1
A good algorithm to securely hash data is BCrypt:
一种安全哈希数据的好算法是BCrypt:
Besides incorporating a salt to protect against rainbow table attacks, bcrypt is an adaptive function: over time, the iteration count can be increased to make it slower, so it remains resistant to brute-force search attacks even with increasing computation power.
bcrypt是一种自适应功能，除了加入盐来防止彩虹表攻击外，还可以增加迭代次数，使其变慢，因此即使计算能力增加，也能抵抗蛮力搜索攻击。
There's a nice .NET implementation of BCrypt that is available also as a NuGet package.
BCrypt有一个很好的。net实现，也可以作为NuGet包使用。
#19
-2
using System;
using System.Collections.Generic;
using System.Text;
using System.Text.RegularExpressions; // This is for password validation
using System.Security.Cryptography;
using System.Configuration; // This is where the hash functions reside
namespace BullyTracker.Common
{
public class HashEncryption
{
//public string GenerateHashvalue(string thisPassword)
//{
// MD5CryptoServiceProvider md5 = new MD5CryptoServiceProvider();
// byte[] tmpSource;
// byte[] tmpHash;
// tmpSource = ASCIIEncoding.ASCII.GetBytes(thisPassword); // Turn password into byte array
// tmpHash = md5.ComputeHash(tmpSource);
// StringBuilder sOutput = new StringBuilder(tmpHash.Length);
// for (int i = 0; i < tmpHash.Length; i++)
// {
// sOutput.Append(tmpHash[i].ToString("X2")); // X2 formats to hexadecimal
// }
// return sOutput.ToString();
//}
//public Boolean VerifyHashPassword(string thisPassword, string thisHash)
//{
// Boolean IsValid = false;
// string tmpHash = GenerateHashvalue(thisPassword); // Call the routine on user input
// if (tmpHash == thisHash) IsValid = true; // Compare to previously generated hash
// return IsValid;
//}
public string GenerateHashvalue(string toEncrypt, bool useHashing)
{
byte[] keyArray;
byte[] toEncryptArray = UTF8Encoding.UTF8.GetBytes(toEncrypt);
System.Configuration.AppSettingsReader settingsReader = new AppSettingsReader();
// Get the key from config file
string key = (string)settingsReader.GetValue("SecurityKey", typeof(String));
//System.Windows.Forms.MessageBox.Show(key);
if (useHashing)
{
MD5CryptoServiceProvider hashmd5 = new MD5CryptoServiceProvider();
keyArray = hashmd5.ComputeHash(UTF8Encoding.UTF8.GetBytes(key));
hashmd5.Clear();
}
else
keyArray = UTF8Encoding.UTF8.GetBytes(key);
TripleDESCryptoServiceProvider tdes = new TripleDESCryptoServiceProvider();
tdes.Key = keyArray;
tdes.Mode = CipherMode.ECB;
tdes.Padding = PaddingMode.PKCS7;
ICryptoTransform cTransform = tdes.CreateEncryptor();
byte[] resultArray = cTransform.TransformFinalBlock(toEncryptArray, 0, toEncryptArray.Length);
tdes.Clear();
return Convert.ToBase64String(resultArray, 0, resultArray.Length);
}
/// <summary>
/// DeCrypt a string using dual encryption method. Return a DeCrypted clear string
/// </summary>
/// <param name="cipherString">encrypted string</param>
/// <param name="useHashing">Did you use hashing to encrypt this data? pass true is yes</param>
/// <returns></returns>
public string Decrypt(string cipherString, bool useHashing)
{
byte[] keyArray;
byte[] toEncryptArray = Convert.FromBase64String(cipherString);
System.Configuration.AppSettingsReader settingsReader = new AppSettingsReader();
//Get your key from config file to open the lock!
string key = (string)settingsReader.GetValue("SecurityKey", typeof(String));
if (useHashing)
{
MD5CryptoServiceProvider hashmd5 = new MD5CryptoServiceProvider();
keyArray = hashmd5.ComputeHash(UTF8Encoding.UTF8.GetBytes(key));
hashmd5.Clear();
}
else
keyArray = UTF8Encoding.UTF8.GetBytes(key);
TripleDESCryptoServiceProvider tdes = new TripleDESCryptoServiceProvider();
tdes.Key = keyArray;
tdes.Mode = CipherMode.ECB;
tdes.Padding = PaddingMode.PKCS7;
ICryptoTransform cTransform = tdes.CreateDecryptor();
byte[] resultArray = cTransform.TransformFinalBlock(toEncryptArray, 0, toEncryptArray.Length);
tdes.Clear();
return UTF8Encoding.UTF8.GetString(resultArray);
}
}
}
#20
-2
for simplicity i made for myself this function that i use for non crypto purposes : replace "yourpassphrase" with your password ...
为了简单起见，我为自己创建了一个用于非加密目的的函数:用密码替换“yourpassphrase”……
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Security.Cryptography;
using System.IO;
namespace My
{
public class strCrypto
{
// This constant string is used as a "salt" value for the PasswordDeriveBytes function calls.
// This size of the IV (in bytes) must = (keysize / 8). Default keysize is 256, so the IV must be
// 32 bytes long. Using a 16 character string here gives us 32 bytes when converted to a byte array.
private const string initVector = "r5dm5fgm24mfhfku";
private const string passPhrase = "yourpassphrase"; // email password encryption password
// This constant is used to determine the keysize of the encryption algorithm.
private const int keysize = 256;
public static string encryptString(string plainText)
{
//if the plaintext is empty or null string just return an empty string
if (plainText == "" || plainText == null )
{
return "";
}
byte[] initVectorBytes = Encoding.UTF8.GetBytes(initVector);
byte[] plainTextBytes = Encoding.UTF8.GetBytes(plainText);
PasswordDeriveBytes password = new PasswordDeriveBytes(passPhrase, null);
byte[] keyBytes = password.GetBytes(keysize / 8);
RijndaelManaged symmetricKey = new RijndaelManaged();
symmetricKey.Mode = CipherMode.CBC;
ICryptoTransform encryptor = symmetricKey.CreateEncryptor(keyBytes, initVectorBytes);
MemoryStream memoryStream = new MemoryStream();
CryptoStream cryptoStream = new CryptoStream(memoryStream, encryptor, CryptoStreamMode.Write);
cryptoStream.Write(plainTextBytes, 0, plainTextBytes.Length);
cryptoStream.FlushFinalBlock();
byte[] cipherTextBytes = memoryStream.ToArray();
memoryStream.Close();
cryptoStream.Close();
return Convert.ToBase64String(cipherTextBytes);
}
public static string decryptString(string cipherText)
{
//if the ciphertext is empty or null string just return an empty string
if (cipherText == "" || cipherText == null )
{
return "";
}
byte[] initVectorBytes = Encoding.ASCII.GetBytes(initVector);
byte[] cipherTextBytes = Convert.FromBase64String(cipherText);
PasswordDeriveBytes password = new PasswordDeriveBytes(passPhrase, null);
byte[] keyBytes = password.GetBytes(keysize / 8);
RijndaelManaged symmetricKey = new RijndaelManaged();
symmetricKey.Mode = CipherMode.CBC;
ICryptoTransform decryptor = symmetricKey.CreateDecryptor(keyBytes, initVectorBytes);
MemoryStream memoryStream = new MemoryStream(cipherTextBytes);
CryptoStream cryptoStream = new CryptoStream(memoryStream, decryptor, CryptoStreamMode.Read);
byte[] plainTextBytes = new byte[cipherTextBytes.Length];
int decryptedByteCount = cryptoStream.Read(plainTextBytes, 0, plainTextBytes.Length);
memoryStream.Close();
cryptoStream.Close();
return Encoding.UTF8.GetString(plainTextBytes, 0, decryptedByteCount);
}
}
}
}
#21
-3
I want to give you my contribute, with my code for AES Rfc2898DeriveBytes (here the documentation) algorhytm, written in C# (.NET framework 4) and fully working also for limited platforms, as .NET Compact Framework for Windows Phone 7.0+ (not all platforms support every criptographic method of the .NET framework!).
我想向您提供我的贡献，以及用c#(这里是文档)编写的AES Rfc2898DeriveBytes (algorhytm)代码。NET framework 4)以及完全适用于有限的平台，如。NET Compact framework for Windows Phone 7.0+(并不是所有平台都支持。NET framework的所有criptographic方法!)
I hope this can help anyone!
我希望这能帮助任何人!
using System;
using System.IO;
using System.Security.Cryptography;
using System.Text;
public static class Crypto
{
private static readonly byte[] IVa = new byte[] { 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x11, 0x11, 0x12, 0x13, 0x14, 0x0e, 0x16, 0x17 };
public static string Encrypt(this string text, string salt)
{
try
{
using (Aes aes = new AesManaged())
{
Rfc2898DeriveBytes deriveBytes = new Rfc2898DeriveBytes(Encoding.UTF8.GetString(IVa, 0, IVa.Length), Encoding.UTF8.GetBytes(salt));
aes.Key = deriveBytes.GetBytes(128 / 8);
aes.IV = aes.Key;
using (MemoryStream encryptionStream = new MemoryStream())
{
using (CryptoStream encrypt = new CryptoStream(encryptionStream, aes.CreateEncryptor(), CryptoStreamMode.Write))
{
byte[] cleanText = Encoding.UTF8.GetBytes(text);
encrypt.Write(cleanText, 0, cleanText.Length);
encrypt.FlushFinalBlock();
}
byte[] encryptedData = encryptionStream.ToArray();
string encryptedText = Convert.ToBase64String(encryptedData);
return encryptedText;
}
}
}
catch
{
return String.Empty;
}
}
public static string Decrypt(this string text, string salt)
{
try
{
using (Aes aes = new AesManaged())
{
Rfc2898DeriveBytes deriveBytes = new Rfc2898DeriveBytes(Encoding.UTF8.GetString(IVa, 0, IVa.Length), Encoding.UTF8.GetBytes(salt));
aes.Key = deriveBytes.GetBytes(128 / 8);
aes.IV = aes.Key;
using (MemoryStream decryptionStream = new MemoryStream())
{
using (CryptoStream decrypt = new CryptoStream(decryptionStream, aes.CreateDecryptor(), CryptoStreamMode.Write))
{
byte[] encryptedData = Convert.FromBase64String(text);
decrypt.Write(encryptedData, 0, encryptedData.Length);
decrypt.Flush();
}
byte[] decryptedData = decryptionStream.ToArray();
string decryptedText = Encoding.UTF8.GetString(decryptedData, 0, decryptedData.Length);
return decryptedText;
}
}
}
catch
{
return String.Empty;
}
}
}
}
#22
-4
using System;
using System.Data;
using System.Configuration;
using System.Text;
using System.Security.Cryptography;
namespace Encription
{
class CryptorEngine
{
public static string Encrypt(string ToEncrypt, bool useHasing)
{
byte[] keyArray;
byte[] toEncryptArray = UTF8Encoding.UTF8.GetBytes(ToEncrypt);
//System.Configuration.AppSettingsReader settingsReader = new AppSettingsReader();
string Key = "Bhagwati";
if (useHasing)
{
MD5CryptoServiceProvider hashmd5 = new MD5CryptoServiceProvider();
keyArray = hashmd5.ComputeHash(UTF8Encoding.UTF8.GetBytes(Key));
hashmd5.Clear();
}
else
{
keyArray = UTF8Encoding.UTF8.GetBytes(Key);
}
TripleDESCryptoServiceProvider tDes = new TripleDESCryptoServiceProvider();
tDes.Key = keyArray;
tDes.Mode = CipherMode.ECB;
tDes.Padding = PaddingMode.PKCS7;
ICryptoTransform cTransform = tDes.CreateEncryptor();
byte[] resultArray = cTransform.TransformFinalBlock(toEncryptArray, 0, toEncryptArray.Length);
tDes.Clear();
return Convert.ToBase64String(resultArray, 0, resultArray.Length);
}
public static string Decrypt(string cypherString, bool useHasing)
{
byte[] keyArray;
byte[] toDecryptArray = Convert.FromBase64String(cypherString);
//byte[] toEncryptArray = Convert.FromBase64String(cypherString);
//System.Configuration.AppSettingsReader settingReader = new AppSettingsReader();
string key = "Bhagwati";
if (useHasing)
{
MD5CryptoServiceProvider hashmd = new MD5CryptoServiceProvider();
keyArray = hashmd.ComputeHash(UTF8Encoding.UTF8.GetBytes(key));
hashmd.Clear();
}
else
{
keyArray = UTF8Encoding.UTF8.GetBytes(key);
}
TripleDESCryptoServiceProvider tDes = new TripleDESCryptoServiceProvider();
tDes.Key = keyArray;
tDes.Mode = CipherMode.ECB;
tDes.Padding = PaddingMode.PKCS7;
ICryptoTransform cTransform = tDes.CreateDecryptor();
try
{
byte[] resultArray = cTransform.TransformFinalBlock(toDecryptArray, 0, toDecryptArray.Length);
tDes.Clear();
return UTF8Encoding.UTF8.GetString(resultArray,0,resultArray.Length);
}
catch (Exception ex)
{
throw ex;
}
}
}
}
#23
-4
You have to use the namespace using System.Security.Cryptography; and useHashing is a bool type either true or false. String variable "key" should be same for Encryption and for Decryption
必须使用System.Security.Cryptography来使用名称空间;而useHashing是一个bool类型，要么是真，要么是假。字符串变量“key”对于加密和解密应该是相同的
//Encryption
public string EncryptText(string toEncrypt, bool useHashing)
{
try
{
byte[] keyArray;
byte[] toEncryptArray = UTF8Encoding.UTF8.GetBytes(toEncrypt);
string key = "String Key Value"; //Based on this key stirng is encrypting
//System.Windows.Forms.MessageBox.Show(key);
//If hashing use get hashcode regards to your key
if (useHashing)
{
MD5CryptoServiceProvider hashmd5 = new MD5CryptoServiceProvider();
keyArray = hashmd5.ComputeHash(UTF8Encoding.UTF8.GetBytes(key));
//Always release the resources and flush data
//of the Cryptographic service provide. Best Practice
hashmd5.Clear();
}
else
keyArray = UTF8Encoding.UTF8.GetBytes(key);
TripleDESCryptoServiceProvider tdes = new TripleDESCryptoServiceProvider();
//set the secret key for the tripleDES algorithm
tdes.Key = keyArray;
//mode of operation. there are other 4 modes. We choose ECB(Electronic code Book)
tdes.Mode = CipherMode.ECB;
//padding mode(if any extra byte added)
tdes.Padding = PaddingMode.PKCS7;
ICryptoTransform cTransform = tdes.CreateEncryptor();
//transform the specified region of bytes array to resultArray
byte[] resultArray = cTransform.TransformFinalBlock(toEncryptArray, 0, toEncryptArray.Length);
//Release resources held by TripleDes Encryptor
tdes.Clear();
//Return the encrypted data into unreadable string format
return Convert.ToBase64String(resultArray, 0, resultArray.Length);
}
catch (Exception e)
{
throw e;
}
}
//Decryption
public string DecryptText(string cipherString, bool useHashing)
{
try
{
byte[] keyArray;
//get the byte code of the string
byte[] toEncryptArray = Convert.FromBase64String(cipherString);
string key = "String Key Value"; //Based on this key string is decrypted
if (useHashing)
{
//if hashing was used get the hash code with regards to your key
MD5CryptoServiceProvider hashmd5 = new MD5CryptoServiceProvider();
keyArray = hashmd5.ComputeHash(UTF8Encoding.UTF8.GetBytes(key));
//release any resource held by the MD5CryptoServiceProvider
hashmd5.Clear();
}
else
{
//if hashing was not implemented get the byte code of the key
keyArray = UTF8Encoding.UTF8.GetBytes(key);
}
TripleDESCryptoServiceProvider tdes = new TripleDESCryptoServiceProvider();
//set the secret key for the tripleDES algorithm
tdes.Key = keyArray;
//mode of operation. there are other 4 modes.
//We choose ECB(Electronic code Book)
tdes.Mode = CipherMode.ECB;
//padding mode(if any extra byte added)
tdes.Padding = PaddingMode.PKCS7;
ICryptoTransform cTransform = tdes.CreateDecryptor();
byte[] resultArray = cTransform.TransformFinalBlock
(toEncryptArray, 0, toEncryptArray.Length);
//Release resources held by TripleDes Encryptor
tdes.Clear();
//return the Clear decrypted TEXT
return UTF8Encoding.UTF8.GetString(resultArray);
}
catch (Exception ex)
{
throw ex;
}
}
#1
384
EDIT 2013-Oct: Although I've edited this answer over time to address shortcomings, please see jbtule's answer for a more robust, informed solution.
编辑2013- 10月:尽管我已经编辑了这个答案以解决缺点，请参阅jbtule的答案，以获得更健壮、更有见地的解决方案。
https://*.com/a/10366194/188474
https://*.com/a/10366194/188474
Original Answer:
最初的回答:
Here's a working example derived from the "RijndaelManaged Class" documentation and the MCTS Training Kit.
下面是一个来自“RijndaelManaged类”文档和MCTS培训包的工作示例。
EDIT 2012-April: This answer was edited to pre-pend the IV per jbtule's suggestion and as illustrated here:
编辑2012- 4月:根据jbtule的建议，这个答案被编辑为pre-pend IV，如下图所示:
http://msdn.microsoft.com/en-us/library/system.security.cryptography.aesmanaged%28v=vs.95%29.aspx
http://msdn.microsoft.com/en-us/library/system.security.cryptography.aesmanaged%28v=vs.95%29.aspx
Good luck!
好运！
public class Crypto
{
//While an app specific salt is not the best practice for
//password based encryption, it's probably safe enough as long as
//it is truly uncommon. Also too much work to alter this answer otherwise.
private static byte[] _salt = __To_Do__("Add a app specific salt here");
/// <summary>
/// Encrypt the given string using AES. The string can be decrypted using
/// DecryptStringAES(). The sharedSecret parameters must match.
/// </summary>
/// <param name="plainText">The text to encrypt.</param>
/// <param name="sharedSecret">A password used to generate a key for encryption.</param>
public static string EncryptStringAES(string plainText, string sharedSecret)
{
if (string.IsNullOrEmpty(plainText))
throw new ArgumentNullException("plainText");
if (string.IsNullOrEmpty(sharedSecret))
throw new ArgumentNullException("sharedSecret");
string outStr = null; // Encrypted string to return
RijndaelManaged aesAlg = null; // RijndaelManaged object used to encrypt the data.
try
{
// generate the key from the shared secret and the salt
Rfc2898DeriveBytes key = new Rfc2898DeriveBytes(sharedSecret, _salt);
// Create a RijndaelManaged object
aesAlg = new RijndaelManaged();
aesAlg.Key = key.GetBytes(aesAlg.KeySize / 8);
// Create a decryptor to perform the stream transform.
ICryptoTransform encryptor = aesAlg.CreateEncryptor(aesAlg.Key, aesAlg.IV);
// Create the streams used for encryption.
using (MemoryStream msEncrypt = new MemoryStream())
{
// prepend the IV
msEncrypt.Write(BitConverter.GetBytes(aesAlg.IV.Length), 0, sizeof(int));
msEncrypt.Write(aesAlg.IV, 0, aesAlg.IV.Length);
using (CryptoStream csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write))
{
using (StreamWriter swEncrypt = new StreamWriter(csEncrypt))
{
//Write all data to the stream.
swEncrypt.Write(plainText);
}
}
outStr = Convert.ToBase64String(msEncrypt.ToArray());
}
}
finally
{
// Clear the RijndaelManaged object.
if (aesAlg != null)
aesAlg.Clear();
}
// Return the encrypted bytes from the memory stream.
return outStr;
}
/// <summary>
/// Decrypt the given string. Assumes the string was encrypted using
/// EncryptStringAES(), using an identical sharedSecret.
/// </summary>
/// <param name="cipherText">The text to decrypt.</param>
/// <param name="sharedSecret">A password used to generate a key for decryption.</param>
public static string DecryptStringAES(string cipherText, string sharedSecret)
{
if (string.IsNullOrEmpty(cipherText))
throw new ArgumentNullException("cipherText");
if (string.IsNullOrEmpty(sharedSecret))
throw new ArgumentNullException("sharedSecret");
// Declare the RijndaelManaged object
// used to decrypt the data.
RijndaelManaged aesAlg = null;
// Declare the string used to hold
// the decrypted text.
string plaintext = null;
try
{
// generate the key from the shared secret and the salt
Rfc2898DeriveBytes key = new Rfc2898DeriveBytes(sharedSecret, _salt);
// Create the streams used for decryption.
byte[] bytes = Convert.FromBase64String(cipherText);
using (MemoryStream msDecrypt = new MemoryStream(bytes))
{
// Create a RijndaelManaged object
// with the specified key and IV.
aesAlg = new RijndaelManaged();
aesAlg.Key = key.GetBytes(aesAlg.KeySize / 8);
// Get the initialization vector from the encrypted stream
aesAlg.IV = ReadByteArray(msDecrypt);
// Create a decrytor to perform the stream transform.
ICryptoTransform decryptor = aesAlg.CreateDecryptor(aesAlg.Key, aesAlg.IV);
using (CryptoStream csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read))
{
using (StreamReader srDecrypt = new StreamReader(csDecrypt))
// Read the decrypted bytes from the decrypting stream
// and place them in a string.
plaintext = srDecrypt.ReadToEnd();
}
}
}
finally
{
// Clear the RijndaelManaged object.
if (aesAlg != null)
aesAlg.Clear();
}
return plaintext;
}
private static byte[] ReadByteArray(Stream s)
{
byte[] rawLength = new byte[sizeof(int)];
if (s.Read(rawLength, 0, rawLength.Length) != rawLength.Length)
{
throw new SystemException("Stream did not contain properly formatted byte array");
}
byte[] buffer = new byte[BitConverter.ToInt32(rawLength, 0)];
if (s.Read(buffer, 0, buffer.Length) != buffer.Length)
{
throw new SystemException("Did not read byte array properly");
}
return buffer;
}
}
#2
316
Modern Examples of Symmetric Authenticated Encryption of a string.
一个字符串的对称验证加密的现代示例。
The general best practice for symmetric encryption is to use Authenticated Encryption with Associated Data (AEAD), however this isn't a part of the standard .net crypto libraries. So the first example uses AES256 and then HMAC256, a two step Encrypt then MAC, which requires more overhead and more keys.
对称加密的一般最佳实践是使用经过身份验证的加密和相关数据(AEAD)，然而这并不是标准的。net加密库的一部分。第一个例子使用AES256和HMAC256，两个步骤加密然后是MAC，这需要更多的开销和更多的密钥。
The second example uses the simpler practice of AES256-GCM using the open source Bouncy Castle (via nuget).
第二个示例使用了使用开源Bouncy Castle(通过nuget)的AES256-GCM更简单的实践。
Both examples have a main function that takes secret message string, key(s) and an optional non-secret payload and return and authenticated encrypted string optionally prepended with the non-secret data. Ideally you would use these with 256bit key(s) randomly generated see NewKey().
这两个示例都有一个主函数，该函数接受秘密消息字符串、密钥和一个可选的非秘密有效负载，并返回经过身份验证的加密字符串，该字符串可选地以非秘密数据的预置。理想的情况下，您可以使用256bit密钥(s)随机生成的see NewKey()。
Both examples also have a helper methods that use a string password to generate the keys. These helper methods are provided as a convenience to match up with other examples, however they are far less secure because the strength of the password is going to be far weaker than a 256 bit key.
两个示例都有一个帮助器方法，该方法使用字符串密码生成键。这些辅助方法是为了方便与其他示例匹配而提供的，但是它们的安全性要差得多，因为密码的强度要比256位密钥弱得多。
Update: Added byte[] overloads, and only the Gist has the full formatting with 4 spaces indent and api docs due to * answer limits.
更新:添加了byte[]重载，由于*的答案限制，只有Gist有4个空格的缩进和api文档的完整格式。
.NET Built-in Encrypt(AES)-Then-MAC(HMAC) [Gist]
net内置加密(AES)-Then-MAC(HMAC)(要点)
/*
* This work (Modern Encryption of a String C#, by James Tuley),
* identified by James Tuley, is free of known copyright restrictions.
* https://gist.github.com/4336842
* http://creativecommons.org/publicdomain/mark/1.0/
*/
using System;
using System.IO;
using System.Security.Cryptography;
using System.Text;
namespace Encryption
{
public static class AESThenHMAC
{
private static readonly RandomNumberGenerator Random = RandomNumberGenerator.Create();
//Preconfigured Encryption Parameters
public static readonly int BlockBitSize = 128;
public static readonly int KeyBitSize = 256;
//Preconfigured Password Key Derivation Parameters
public static readonly int SaltBitSize = 64;
public static readonly int Iterations = 10000;
public static readonly int MinPasswordLength = 12;
/// <summary>
/// Helper that generates a random key on each call.
/// </summary>
/// <returns></returns>
public static byte[] NewKey()
{
var key = new byte[KeyBitSize / 8];
Random.GetBytes(key);
return key;
}
/// <summary>
/// Simple Encryption (AES) then Authentication (HMAC) for a UTF8 Message.
/// </summary>
/// <param name="secretMessage">The secret message.</param>
/// <param name="cryptKey">The crypt key.</param>
/// <param name="authKey">The auth key.</param>
/// <param name="nonSecretPayload">(Optional) Non-Secret Payload.</param>
/// <returns>
/// Encrypted Message
/// </returns>
/// <exception cref="System.ArgumentException">Secret Message Required!;secretMessage</exception>
/// <remarks>
/// Adds overhead of (Optional-Payload + BlockSize(16) + Message-Padded-To-Blocksize + HMac-Tag(32)) * 1.33 Base64
/// </remarks>
public static string SimpleEncrypt(string secretMessage, byte[] cryptKey, byte[] authKey,
byte[] nonSecretPayload = null)
{
if (string.IsNullOrEmpty(secretMessage))
throw new ArgumentException("Secret Message Required!", "secretMessage");
var plainText = Encoding.UTF8.GetBytes(secretMessage);
var cipherText = SimpleEncrypt(plainText, cryptKey, authKey, nonSecretPayload);
return Convert.ToBase64String(cipherText);
}
/// <summary>
/// Simple Authentication (HMAC) then Decryption (AES) for a secrets UTF8 Message.
/// </summary>
/// <param name="encryptedMessage">The encrypted message.</param>
/// <param name="cryptKey">The crypt key.</param>
/// <param name="authKey">The auth key.</param>
/// <param name="nonSecretPayloadLength">Length of the non secret payload.</param>
/// <returns>
/// Decrypted Message
/// </returns>
/// <exception cref="System.ArgumentException">Encrypted Message Required!;encryptedMessage</exception>
public static string SimpleDecrypt(string encryptedMessage, byte[] cryptKey, byte[] authKey,
int nonSecretPayloadLength = 0)
{
if (string.IsNullOrWhiteSpace(encryptedMessage))
throw new ArgumentException("Encrypted Message Required!", "encryptedMessage");
var cipherText = Convert.FromBase64String(encryptedMessage);
var plainText = SimpleDecrypt(cipherText, cryptKey, authKey, nonSecretPayloadLength);
return plainText == null ? null : Encoding.UTF8.GetString(plainText);
}
/// <summary>
/// Simple Encryption (AES) then Authentication (HMAC) of a UTF8 message
/// using Keys derived from a Password (PBKDF2).
/// </summary>
/// <param name="secretMessage">The secret message.</param>
/// <param name="password">The password.</param>
/// <param name="nonSecretPayload">The non secret payload.</param>
/// <returns>
/// Encrypted Message
/// </returns>
/// <exception cref="System.ArgumentException">password</exception>
/// <remarks>
/// Significantly less secure than using random binary keys.
/// Adds additional non secret payload for key generation parameters.
/// </remarks>
public static string SimpleEncryptWithPassword(string secretMessage, string password,
byte[] nonSecretPayload = null)
{
if (string.IsNullOrEmpty(secretMessage))
throw new ArgumentException("Secret Message Required!", "secretMessage");
var plainText = Encoding.UTF8.GetBytes(secretMessage);
var cipherText = SimpleEncryptWithPassword(plainText, password, nonSecretPayload);
return Convert.ToBase64String(cipherText);
}
/// <summary>
/// Simple Authentication (HMAC) and then Descryption (AES) of a UTF8 Message
/// using keys derived from a password (PBKDF2).
/// </summary>
/// <param name="encryptedMessage">The encrypted message.</param>
/// <param name="password">The password.</param>
/// <param name="nonSecretPayloadLength">Length of the non secret payload.</param>
/// <returns>
/// Decrypted Message
/// </returns>
/// <exception cref="System.ArgumentException">Encrypted Message Required!;encryptedMessage</exception>
/// <remarks>
/// Significantly less secure than using random binary keys.
/// </remarks>
public static string SimpleDecryptWithPassword(string encryptedMessage, string password,
int nonSecretPayloadLength = 0)
{
if (string.IsNullOrWhiteSpace(encryptedMessage))
throw new ArgumentException("Encrypted Message Required!", "encryptedMessage");
var cipherText = Convert.FromBase64String(encryptedMessage);
var plainText = SimpleDecryptWithPassword(cipherText, password, nonSecretPayloadLength);
return plainText == null ? null : Encoding.UTF8.GetString(plainText);
}
public static byte[] SimpleEncrypt(byte[] secretMessage, byte[] cryptKey, byte[] authKey, byte[] nonSecretPayload = null)
{
//User Error Checks
if (cryptKey == null || cryptKey.Length != KeyBitSize / 8)
throw new ArgumentException(String.Format("Key needs to be {0} bit!", KeyBitSize), "cryptKey");
if (authKey == null || authKey.Length != KeyBitSize / 8)
throw new ArgumentException(String.Format("Key needs to be {0} bit!", KeyBitSize), "authKey");
if (secretMessage == null || secretMessage.Length < 1)
throw new ArgumentException("Secret Message Required!", "secretMessage");
//non-secret payload optional
nonSecretPayload = nonSecretPayload ?? new byte[] { };
byte[] cipherText;
byte[] iv;
using (var aes = new AesManaged
{
KeySize = KeyBitSize,
BlockSize = BlockBitSize,
Mode = CipherMode.CBC,
Padding = PaddingMode.PKCS7
})
{
//Use random IV
aes.GenerateIV();
iv = aes.IV;
using (var encrypter = aes.CreateEncryptor(cryptKey, iv))
using (var cipherStream = new MemoryStream())
{
using (var cryptoStream = new CryptoStream(cipherStream, encrypter, CryptoStreamMode.Write))
using (var binaryWriter = new BinaryWriter(cryptoStream))
{
//Encrypt Data
binaryWriter.Write(secretMessage);
}
cipherText = cipherStream.ToArray();
}
}
//Assemble encrypted message and add authentication
using (var hmac = new HMACSHA256(authKey))
using (var encryptedStream = new MemoryStream())
{
using (var binaryWriter = new BinaryWriter(encryptedStream))
{
//Prepend non-secret payload if any
binaryWriter.Write(nonSecretPayload);
//Prepend IV
binaryWriter.Write(iv);
//Write Ciphertext
binaryWriter.Write(cipherText);
binaryWriter.Flush();
//Authenticate all data
var tag = hmac.ComputeHash(encryptedStream.ToArray());
//Postpend tag
binaryWriter.Write(tag);
}
return encryptedStream.ToArray();
}
}
public static byte[] SimpleDecrypt(byte[] encryptedMessage, byte[] cryptKey, byte[] authKey, int nonSecretPayloadLength = 0)
{
//Basic Usage Error Checks
if (cryptKey == null || cryptKey.Length != KeyBitSize / 8)
throw new ArgumentException(String.Format("CryptKey needs to be {0} bit!", KeyBitSize), "cryptKey");
if (authKey == null || authKey.Length != KeyBitSize / 8)
throw new ArgumentException(String.Format("AuthKey needs to be {0} bit!", KeyBitSize), "authKey");
if (encryptedMessage == null || encryptedMessage.Length == 0)
throw new ArgumentException("Encrypted Message Required!", "encryptedMessage");
using (var hmac = new HMACSHA256(authKey))
{
var sentTag = new byte[hmac.HashSize / 8];
//Calculate Tag
var calcTag = hmac.ComputeHash(encryptedMessage, 0, encryptedMessage.Length - sentTag.Length);
var ivLength = (BlockBitSize / 8);
//if message length is to small just return null
if (encryptedMessage.Length < sentTag.Length + nonSecretPayloadLength + ivLength)
return null;
//Grab Sent Tag
Array.Copy(encryptedMessage, encryptedMessage.Length - sentTag.Length, sentTag, 0, sentTag.Length);
//Compare Tag with constant time comparison
var compare = 0;
for (var i = 0; i < sentTag.Length; i++)
compare |= sentTag[i] ^ calcTag[i];
//if message doesn't authenticate return null
if (compare != 0)
return null;
using (var aes = new AesManaged
{
KeySize = KeyBitSize,
BlockSize = BlockBitSize,
Mode = CipherMode.CBC,
Padding = PaddingMode.PKCS7
})
{
//Grab IV from message
var iv = new byte[ivLength];
Array.Copy(encryptedMessage, nonSecretPayloadLength, iv, 0, iv.Length);
using (var decrypter = aes.CreateDecryptor(cryptKey, iv))
using (var plainTextStream = new MemoryStream())
{
using (var decrypterStream = new CryptoStream(plainTextStream, decrypter, CryptoStreamMode.Write))
using (var binaryWriter = new BinaryWriter(decrypterStream))
{
//Decrypt Cipher Text from Message
binaryWriter.Write(
encryptedMessage,
nonSecretPayloadLength + iv.Length,
encryptedMessage.Length - nonSecretPayloadLength - iv.Length - sentTag.Length
);
}
//Return Plain Text
return plainTextStream.ToArray();
}
}
}
}
public static byte[] SimpleEncryptWithPassword(byte[] secretMessage, string password, byte[] nonSecretPayload = null)
{
nonSecretPayload = nonSecretPayload ?? new byte[] {};
//User Error Checks
if (string.IsNullOrWhiteSpace(password) || password.Length < MinPasswordLength)
throw new ArgumentException(String.Format("Must have a password of at least {0} characters!", MinPasswordLength), "password");
if (secretMessage == null || secretMessage.Length ==0)
throw new ArgumentException("Secret Message Required!", "secretMessage");
var payload = new byte[((SaltBitSize / 8) * 2) + nonSecretPayload.Length];
Array.Copy(nonSecretPayload, payload, nonSecretPayload.Length);
int payloadIndex = nonSecretPayload.Length;
byte[] cryptKey;
byte[] authKey;
//Use Random Salt to prevent pre-generated weak password attacks.
using (var generator = new Rfc2898DeriveBytes(password, SaltBitSize / 8, Iterations))
{
var salt = generator.Salt;
//Generate Keys
cryptKey = generator.GetBytes(KeyBitSize / 8);
//Create Non Secret Payload
Array.Copy(salt, 0, payload, payloadIndex, salt.Length);
payloadIndex += salt.Length;
}
//Deriving separate key, might be less efficient than using HKDF,
//but now compatible with RNEncryptor which had a very similar wireformat and requires less code than HKDF.
using (var generator = new Rfc2898DeriveBytes(password, SaltBitSize / 8, Iterations))
{
var salt = generator.Salt;
//Generate Keys
authKey = generator.GetBytes(KeyBitSize / 8);
//Create Rest of Non Secret Payload
Array.Copy(salt, 0, payload, payloadIndex, salt.Length);
}
return SimpleEncrypt(secretMessage, cryptKey, authKey, payload);
}
public static byte[] SimpleDecryptWithPassword(byte[] encryptedMessage, string password, int nonSecretPayloadLength = 0)
{
//User Error Checks
if (string.IsNullOrWhiteSpace(password) || password.Length < MinPasswordLength)
throw new ArgumentException(String.Format("Must have a password of at least {0} characters!", MinPasswordLength), "password");
if (encryptedMessage == null || encryptedMessage.Length == 0)
throw new ArgumentException("Encrypted Message Required!", "encryptedMessage");
var cryptSalt = new byte[SaltBitSize / 8];
var authSalt = new byte[SaltBitSize / 8];
//Grab Salt from Non-Secret Payload
Array.Copy(encryptedMessage, nonSecretPayloadLength, cryptSalt, 0, cryptSalt.Length);
Array.Copy(encryptedMessage, nonSecretPayloadLength + cryptSalt.Length, authSalt, 0, authSalt.Length);
byte[] cryptKey;
byte[] authKey;
//Generate crypt key
using (var generator = new Rfc2898DeriveBytes(password, cryptSalt, Iterations))
{
cryptKey = generator.GetBytes(KeyBitSize / 8);
}
//Generate auth key
using (var generator = new Rfc2898DeriveBytes(password, authSalt, Iterations))
{
authKey = generator.GetBytes(KeyBitSize / 8);
}
return SimpleDecrypt(encryptedMessage, cryptKey, authKey, cryptSalt.Length + authSalt.Length + nonSecretPayloadLength);
}
}
}
Bouncy Castle AES-GCM [Gist]
Bouncy Castle AES-GCM(要点)
/*
* This work (Modern Encryption of a String C#, by James Tuley),
* identified by James Tuley, is free of known copyright restrictions.
* https://gist.github.com/4336842
* http://creativecommons.org/publicdomain/mark/1.0/
*/
using System;
using System.IO;
using System.Text;
using Org.BouncyCastle.Crypto;
using Org.BouncyCastle.Crypto.Engines;
using Org.BouncyCastle.Crypto.Generators;
using Org.BouncyCastle.Crypto.Modes;
using Org.BouncyCastle.Crypto.Parameters;
using Org.BouncyCastle.Security;
namespace Encryption
{
public static class AESGCM
{
private static readonly SecureRandom Random = new SecureRandom();
//Preconfigured Encryption Parameters
public static readonly int NonceBitSize = 128;
public static readonly int MacBitSize = 128;
public static readonly int KeyBitSize = 256;
//Preconfigured Password Key Derivation Parameters
public static readonly int SaltBitSize = 128;
public static readonly int Iterations = 10000;
public static readonly int MinPasswordLength = 12;
/// <summary>
/// Helper that generates a random new key on each call.
/// </summary>
/// <returns></returns>
public static byte[] NewKey()
{
var key = new byte[KeyBitSize / 8];
Random.NextBytes(key);
return key;
}
/// <summary>
/// Simple Encryption And Authentication (AES-GCM) of a UTF8 string.
/// </summary>
/// <param name="secretMessage">The secret message.</param>
/// <param name="key">The key.</param>
/// <param name="nonSecretPayload">Optional non-secret payload.</param>
/// <returns>
/// Encrypted Message
/// </returns>
/// <exception cref="System.ArgumentException">Secret Message Required!;secretMessage</exception>
/// <remarks>
/// Adds overhead of (Optional-Payload + BlockSize(16) + Message + HMac-Tag(16)) * 1.33 Base64
/// </remarks>
public static string SimpleEncrypt(string secretMessage, byte[] key, byte[] nonSecretPayload = null)
{
if (string.IsNullOrEmpty(secretMessage))
throw new ArgumentException("Secret Message Required!", "secretMessage");
var plainText = Encoding.UTF8.GetBytes(secretMessage);
var cipherText = SimpleEncrypt(plainText, key, nonSecretPayload);
return Convert.ToBase64String(cipherText);
}
/// <summary>
/// Simple Decryption & Authentication (AES-GCM) of a UTF8 Message
/// </summary>
/// <param name="encryptedMessage">The encrypted message.</param>
/// <param name="key">The key.</param>
/// <param name="nonSecretPayloadLength">Length of the optional non-secret payload.</param>
/// <returns>Decrypted Message</returns>
public static string SimpleDecrypt(string encryptedMessage, byte[] key, int nonSecretPayloadLength = 0)
{
if (string.IsNullOrEmpty(encryptedMessage))
throw new ArgumentException("Encrypted Message Required!", "encryptedMessage");
var cipherText = Convert.FromBase64String(encryptedMessage);
var plainText = SimpleDecrypt(cipherText, key, nonSecretPayloadLength);
return plainText == null ? null : Encoding.UTF8.GetString(plainText);
}
/// <summary>
/// Simple Encryption And Authentication (AES-GCM) of a UTF8 String
/// using key derived from a password (PBKDF2).
/// </summary>
/// <param name="secretMessage">The secret message.</param>
/// <param name="password">The password.</param>
/// <param name="nonSecretPayload">The non secret payload.</param>
/// <returns>
/// Encrypted Message
/// </returns>
/// <remarks>
/// Significantly less secure than using random binary keys.
/// Adds additional non secret payload for key generation parameters.
/// </remarks>
public static string SimpleEncryptWithPassword(string secretMessage, string password,
byte[] nonSecretPayload = null)
{
if (string.IsNullOrEmpty(secretMessage))
throw new ArgumentException("Secret Message Required!", "secretMessage");
var plainText = Encoding.UTF8.GetBytes(secretMessage);
var cipherText = SimpleEncryptWithPassword(plainText, password, nonSecretPayload);
return Convert.ToBase64String(cipherText);
}
/// <summary>
/// Simple Decryption and Authentication (AES-GCM) of a UTF8 message
/// using a key derived from a password (PBKDF2)
/// </summary>
/// <param name="encryptedMessage">The encrypted message.</param>
/// <param name="password">The password.</param>
/// <param name="nonSecretPayloadLength">Length of the non secret payload.</param>
/// <returns>
/// Decrypted Message
/// </returns>
/// <exception cref="System.ArgumentException">Encrypted Message Required!;encryptedMessage</exception>
/// <remarks>
/// Significantly less secure than using random binary keys.
/// </remarks>
public static string SimpleDecryptWithPassword(string encryptedMessage, string password,
int nonSecretPayloadLength = 0)
{
if (string.IsNullOrWhiteSpace(encryptedMessage))
throw new ArgumentException("Encrypted Message Required!", "encryptedMessage");
var cipherText = Convert.FromBase64String(encryptedMessage);
var plainText = SimpleDecryptWithPassword(cipherText, password, nonSecretPayloadLength);
return plainText == null ? null : Encoding.UTF8.GetString(plainText);
}
public static byte[] SimpleEncrypt(byte[] secretMessage, byte[] key, byte[] nonSecretPayload = null)
{
//User Error Checks
if (key == null || key.Length != KeyBitSize / 8)
throw new ArgumentException(String.Format("Key needs to be {0} bit!", KeyBitSize), "key");
if (secretMessage == null || secretMessage.Length == 0)
throw new ArgumentException("Secret Message Required!", "secretMessage");
//Non-secret Payload Optional
nonSecretPayload = nonSecretPayload ?? new byte[] { };
//Using random nonce large enough not to repeat
var nonce = new byte[NonceBitSize / 8];
Random.NextBytes(nonce, 0, nonce.Length);
var cipher = new GcmBlockCipher(new AesFastEngine());
var parameters = new AeadParameters(new KeyParameter(key), MacBitSize, nonce, nonSecretPayload);
cipher.Init(true, parameters);
//Generate Cipher Text With Auth Tag
var cipherText = new byte[cipher.GetOutputSize(secretMessage.Length)];
var len = cipher.ProcessBytes(secretMessage, 0, secretMessage.Length, cipherText, 0);
cipher.DoFinal(cipherText, len);
//Assemble Message
using (var combinedStream = new MemoryStream())
{
using (var binaryWriter = new BinaryWriter(combinedStream))
{
//Prepend Authenticated Payload
binaryWriter.Write(nonSecretPayload);
//Prepend Nonce
binaryWriter.Write(nonce);
//Write Cipher Text
binaryWriter.Write(cipherText);
}
return combinedStream.ToArray();
}
}
public static byte[] SimpleDecrypt(byte[] encryptedMessage, byte[] key, int nonSecretPayloadLength = 0)
{
//User Error Checks
if (key == null || key.Length != KeyBitSize / 8)
throw new ArgumentException(String.Format("Key needs to be {0} bit!", KeyBitSize), "key");
if (encryptedMessage == null || encryptedMessage.Length == 0)
throw new ArgumentException("Encrypted Message Required!", "encryptedMessage");
using (var cipherStream = new MemoryStream(encryptedMessage))
using (var cipherReader = new BinaryReader(cipherStream))
{
//Grab Payload
var nonSecretPayload = cipherReader.ReadBytes(nonSecretPayloadLength);
//Grab Nonce
var nonce = cipherReader.ReadBytes(NonceBitSize / 8);
var cipher = new GcmBlockCipher(new AesFastEngine());
var parameters = new AeadParameters(new KeyParameter(key), MacBitSize, nonce, nonSecretPayload);
cipher.Init(false, parameters);
//Decrypt Cipher Text
var cipherText = cipherReader.ReadBytes(encryptedMessage.Length - nonSecretPayloadLength - nonce.Length);
var plainText = new byte[cipher.GetOutputSize(cipherText.Length)];
try
{
var len = cipher.ProcessBytes(cipherText, 0, cipherText.Length, plainText, 0);
cipher.DoFinal(plainText, len);
}
catch (InvalidCipherTextException)
{
//Return null if it doesn't authenticate
return null;
}
return plainText;
}
}
public static byte[] SimpleEncryptWithPassword(byte[] secretMessage, string password, byte[] nonSecretPayload = null)
{
nonSecretPayload = nonSecretPayload ?? new byte[] {};
//User Error Checks
if (string.IsNullOrWhiteSpace(password) || password.Length < MinPasswordLength)
throw new ArgumentException(String.Format("Must have a password of at least {0} characters!", MinPasswordLength), "password");
if (secretMessage == null || secretMessage.Length == 0)
throw new ArgumentException("Secret Message Required!", "secretMessage");
var generator = new Pkcs5S2ParametersGenerator();
//Use Random Salt to minimize pre-generated weak password attacks.
var salt = new byte[SaltBitSize / 8];
Random.NextBytes(salt);
generator.Init(
PbeParametersGenerator.Pkcs5PasswordToBytes(password.ToCharArray()),
salt,
Iterations);
//Generate Key
var key = (KeyParameter)generator.GenerateDerivedMacParameters(KeyBitSize);
//Create Full Non Secret Payload
var payload = new byte[salt.Length + nonSecretPayload.Length];
Array.Copy(nonSecretPayload, payload, nonSecretPayload.Length);
Array.Copy(salt,0, payload,nonSecretPayload.Length, salt.Length);
return SimpleEncrypt(secretMessage, key.GetKey(), payload);
}
public static byte[] SimpleDecryptWithPassword(byte[] encryptedMessage, string password, int nonSecretPayloadLength = 0)
{
//User Error Checks
if (string.IsNullOrWhiteSpace(password) || password.Length < MinPasswordLength)
throw new ArgumentException(String.Format("Must have a password of at least {0} characters!", MinPasswordLength), "password");
if (encryptedMessage == null || encryptedMessage.Length == 0)
throw new ArgumentException("Encrypted Message Required!", "encryptedMessage");
var generator = new Pkcs5S2ParametersGenerator();
//Grab Salt from Payload
var salt = new byte[SaltBitSize / 8];
Array.Copy(encryptedMessage, nonSecretPayloadLength, salt, 0, salt.Length);
generator.Init(
PbeParametersGenerator.Pkcs5PasswordToBytes(password.ToCharArray()),
salt,
Iterations);
//Generate Key
var key = (KeyParameter)generator.GenerateDerivedMacParameters(KeyBitSize);
return SimpleDecrypt(encryptedMessage, key.GetKey(), salt.Length + nonSecretPayloadLength);
}
}
}
#3
98
Here is an example using RSA.
这里有一个使用RSA的例子。
Important: There is a limit to the size of data you can encrypt with the RSA encryption, KeySize - MinimumPadding. e.g. 256 bytes (assuming 2048 bit key) - 42 bytes (min OEAP padding) = 214 bytes (max plaintext size)
重要提示:有一个限制的数据大小，你可以加密的RSA加密，密钥大小-最小填充。例如，256字节(假设2048位键)- 42字节(最小OEAP填充)= 214字节(最大纯文本大小)
Replace your_rsa_key with your RSA key.
用RSA密钥替换您的_rsa_key。
var provider = new System.Security.Cryptography.RSACryptoServiceProvider();
provider.ImportParameters(your_rsa_key);
var encryptedBytes = provider.Encrypt(
System.Text.Encoding.UTF8.GetBytes("Hello World!"), true);
string decryptedTest = System.Text.Encoding.UTF8.GetString(
provider.Decrypt(encryptedBytes, true));
For more info, visit MSDN - RSACryptoServiceProvider
有关更多信息，请访问MSDN - RSACryptoServiceProvider
#4
48
If you are using ASP.Net you can now use built in functionality in .Net 4.0 onwards.
如果您正在使用ASP。Net现在可以使用。Net 4.0中的内置功能。
System.Web.Security.MachineKey
System.Web.Security.MachineKey
.Net 4.5 has MachineKey.Protect() and MachineKey.Unprotect().
. net 4.5有machine ekey . protect()和MachineKey.Unprotect()。
.Net 4.0 has MachineKey.Encode() and MachineKey.Decode(). You should just set the MachineKeyProtection to 'All'.
. net 4.0有machine ekey . encode()和MachineKey.Decode()。你应该将机器密钥保护设置为“All”。
Outside of ASP.Net this class seems to generate a new key with every app restart so doesn't work. With a quick peek in ILSpy it looks to me like it generates its own defaults if the appropriate app.settings are missing. So you may actually be able to set it up outside ASP.Net.
在ASP。Net这个类似乎会在每个应用重新启动时生成一个新键，因此无法工作。通过快速查看ILSpy，我觉得如果适当的应用程序没有设置，它会生成自己的默认值。所以你可以把它设置在ASP.Net之外。
I haven't been able to find a non-ASP.Net equivalent outside the System.Web namespace.
我还没有找到非asp。在系统之外的净等价。网络名称空间。
#5
45
BouncyCastle is a great Crypto library for .NET, it's available as a Nuget package for install into your projects. I like it a lot more than what's currently available in the System.Security.Cryptography library. It gives you a lot more options in terms of available algorithms, and provides more modes for those algorithms.
BouncyCastle是一个很棒的. net加密库，它可以作为Nuget包安装到项目中。我喜欢它比目前在System.Security中可用的要多得多。加密库。它提供了更多可用算法的选项，并为这些算法提供了更多的模式。
This is an example of an implementation of TwoFish, which was written by Bruce Schneier (hero to all us paranoid people out there). It's a symmetric algorithm like the Rijndael (aka AES). It was one of the three finalists for the AES standard and sibling to another famous algorithm written by Bruce Schneier called BlowFish.
这是一个实现TwoFish的例子，由Bruce Schneier(我们这些偏执的人的英雄)编写。它是一种像Rijndael(又名AES)一样的对称算法。这是AES标准和兄弟姐妹的三个入围作品之一，这是布鲁斯·施奈德(Bruce Schneier)写的另一种著名的算法，名叫“BlowFish”。
First thing with bouncycastle is to create an encryptor class, this will make it easier to implement other block ciphers within the library. The following encryptor class takes in a generic argument T where T implements IBlockCipher and has a default constructor.
使用bouncycastle的第一件事是创建encryptor类，这将使在库中实现其他块密码更容易。下面的encryptor类接受通用参数T，其中T实现IBlockCipher，并具有默认构造函数。
UPDATE: Due to popular demand I have decided to implement generating a random IV as well as include an HMAC into this class. Although from a style perspective this goes against the SOLID principle of single responsibility, because of the nature of what this class does I reniged. This class will now take two generic parameters, one for the cipher and one for the digest. It automatically generates the IV using RNGCryptoServiceProvider to provide good RNG entropy, and allows you to use whatever digest algorithm you want from BouncyCastle to generate the MAC.
更新:由于流行的需求，我已经决定实现生成一个随机的IV以及包含一个HMAC到这个类中。尽管从风格的角度来看，这违背了单一责任的坚实原则，因为这门课的本质是我所认识的。这个类现在将使用两个通用参数，一个用于密码，另一个用于摘要。它使用RNGCryptoServiceProvider自动生成IV，以提供良好的RNG熵，并允许您使用从BouncyCastle获得的任何摘要算法来生成MAC。
using System;
using System.Security.Cryptography;
using System.Text;
using Org.BouncyCastle.Crypto;
using Org.BouncyCastle.Crypto.Macs;
using Org.BouncyCastle.Crypto.Modes;
using Org.BouncyCastle.Crypto.Paddings;
using Org.BouncyCastle.Crypto.Parameters;
public sealed class Encryptor<TBlockCipher, TDigest>
where TBlockCipher : IBlockCipher, new()
where TDigest : IDigest, new()
{
private Encoding encoding;
private IBlockCipher blockCipher;
private BufferedBlockCipher cipher;
private HMac mac;
private byte[] key;
public Encryptor(Encoding encoding, byte[] key, byte[] macKey)
{
this.encoding = encoding;
this.key = key;
this.Init(key, macKey, new Pkcs7Padding());
}
public Encryptor(Encoding encoding, byte[] key, byte[] macKey, IBlockCipherPadding padding)
{
this.encoding = encoding;
this.key = key;
this.Init(key, macKey, padding);
}
private void Init(byte[] key, byte[] macKey, IBlockCipherPadding padding)
{
this.blockCipher = new CbcBlockCipher(new TBlockCipher());
this.cipher = new PaddedBufferedBlockCipher(this.blockCipher, padding);
this.mac = new HMac(new TDigest());
this.mac.Init(new KeyParameter(macKey));
}
public string Encrypt(string plain)
{
return Convert.ToBase64String(EncryptBytes(plain));
}
public byte[] EncryptBytes(string plain)
{
byte[] input = this.encoding.GetBytes(plain);
var iv = this.GenerateIV();
var cipher = this.BouncyCastleCrypto(true, input, new ParametersWithIV(new KeyParameter(key), iv));
byte[] message = CombineArrays(iv, cipher);
this.mac.Reset();
this.mac.BlockUpdate(message, 0, message.Length);
byte[] digest = new byte[this.mac.GetUnderlyingDigest().GetDigestSize()];
this.mac.DoFinal(digest, 0);
var result = CombineArrays(digest, message);
return result;
}
public byte[] DecryptBytes(byte[] bytes)
{
// split the digest into component parts
var digest = new byte[this.mac.GetUnderlyingDigest().GetDigestSize()];
var message = new byte[bytes.Length - digest.Length];
var iv = new byte[this.blockCipher.GetBlockSize()];
var cipher = new byte[message.Length - iv.Length];
Buffer.BlockCopy(bytes, 0, digest, 0, digest.Length);
Buffer.BlockCopy(bytes, digest.Length, message, 0, message.Length);
if (!IsValidHMac(digest, message))
{
throw new CryptoException();
}
Buffer.BlockCopy(message, 0, iv, 0, iv.Length);
Buffer.BlockCopy(message, iv.Length, cipher, 0, cipher.Length);
byte[] result = this.BouncyCastleCrypto(false, cipher, new ParametersWithIV(new KeyParameter(key), iv));
return result;
}
public string Decrypt(byte[] bytes)
{
return this.encoding.GetString(DecryptBytes(bytes));
}
public string Decrypt(string cipher)
{
return this.Decrypt(Convert.FromBase64String(cipher));
}
private bool IsValidHMac(byte[] digest, byte[] message)
{
this.mac.Reset();
this.mac.BlockUpdate(message, 0, message.Length);
byte[] computed = new byte[this.mac.GetUnderlyingDigest().GetDigestSize()];
this.mac.DoFinal(computed, 0);
return AreEqual(digest,computed);
}
private static bool AreEqual(byte [] digest, byte[] computed)
{
if(digest.Length != computed.Length)
{
return false;
}
int result = 0;
for (int i = 0; i < digest.Length; i++)
{
// compute equality of all bytes before returning.
// helps prevent timing attacks:
// https://codahale.com/a-lesson-in-timing-attacks/
result |= digest[i] ^ computed[i];
}
return result == 0;
}
private byte[] BouncyCastleCrypto(bool forEncrypt, byte[] input, ICipherParameters parameters)
{
try
{
cipher.Init(forEncrypt, parameters);
return this.cipher.DoFinal(input);
}
catch (CryptoException)
{
throw;
}
}
private byte[] GenerateIV()
{
using (var provider = new RNGCryptoServiceProvider())
{
// 1st block
byte[] result = new byte[this.blockCipher.GetBlockSize()];
provider.GetBytes(result);
return result;
}
}
private static byte[] CombineArrays(byte[] source1, byte[] source2)
{
byte[] result = new byte[source1.Length + source2.Length];
Buffer.BlockCopy(source1, 0, result, 0, source1.Length);
Buffer.BlockCopy(source2, 0, result, source1.Length, source2.Length);
return result;
}
}
Next just call the encrypt and decrypt methods on the new class, here's the example using twofish:
接下来只需调用新类上的加密和解密方法，这里是使用twofish的示例:
var encrypt = new Encryptor<TwofishEngine, Sha1Digest>(Encoding.UTF8, key, hmacKey);
string cipher = encrypt.Encrypt("TEST");
string plainText = encrypt.Decrypt(cipher);
It's just as easy to substitute another block cipher like TripleDES:
用另一个块密码就像TripleDES一样简单:
var des = new Encryptor<DesEdeEngine, Sha1Digest>(Encoding.UTF8, key, hmacKey);
string cipher = des.Encrypt("TEST");
string plainText = des.Decrypt(cipher);
Finally if you want to use AES with SHA256 HMAC you can do the following:
最后，如果你想使用AES与SHA256 HMAC，你可以做以下:
var aes = new Encryptor<AesEngine, Sha256Digest>(Encoding.UTF8, key, hmacKey);
cipher = aes.Encrypt("TEST");
plainText = aes.Decrypt(cipher);
The hardest part about encryption actually deals with the keys and not the algorithms. You'll have to think about where you store your keys, and if you have to, how you exchange them. These algorithms have all withstood the test of time, and are extremely hard to break. Someone who wants to steal information from you isn't going to spend eternity doing cryptanalysis on your messages, they're going to try to figure out what or where your key is. So #1 choose your keys wisely, #2 store them in a safe place, if you use a web.config and IIS then you can encrypt parts of the the web.config, and finally if you have to exchange keys make sure that your protocol for exchanging the key is secure.
加密最难的部分实际上是处理密钥，而不是算法。你必须考虑你的钥匙放在哪里，如果需要的话，如何交换。这些算法都经受住了时间的考验，而且很难打破。那些想从你那里窃取信息的人不会花时间对你的信息进行密码分析，他们会试图找出你的钥匙在哪里。所以，如果你使用网络，第一点要明智地选择你的钥匙，第二点要把钥匙放在安全的地方。配置和IIS，然后您可以加密部分web。配置，最后，如果您必须交换密钥，请确保交换密钥的协议是安全的。
Update 2 Changed compare method to mitigate against timing attacks. See more info here http://codahale.com/a-lesson-in-timing-attacks/ . Also updated to default to PKCS7 padding and added new constructor to allow end user the ability to choose which padding they would like to use. Thanks @CodesInChaos for the suggestions.
更新2更改了比较方法以减少定时攻击。查看更多信息http://codahale.com/a-lesson-in- time -attacks/。还更新为默认的PKCS7填充，并添加了新的构造函数，以便最终用户能够选择他们想要使用的填充。感谢@CodesInChaos的建议。
#6
14
Disclaimer: This solution should only be used for data at rest that is not exposed to the public (for example - a configuration file or DB). Only in this scenario, the quick-and-dirty solution can be considered better than @jbtule's solution, due to lower maintanance.
免责声明:此解决方案应该只用于不公开的静态数据(例如，配置文件或DB)。只有在这种情况下，由于主色调较低，可以认为快速且肮脏的解决方案比@jbtule的解决方案要好。
Original post: I found jbtule's answer a bit complicated for a quick and dirty secured AES string encryption and Brett's answer had a bug with the Initialization Vector being a fixed value making it vulnerable to padding attacks, so I fixed Brett's code and added a random IV that is added to the chipered string, creating a different encrypted value each and every encryption of the same value:
原来的帖子:我发现jbtule的回答有点复杂的快速和肮脏的AES加密字符串和布雷特的回答有错误和初始化向量是一个固定值使其容易填充攻击,所以我固定布雷特的代码和添加了一个随机字符串添加到chipered IV,创建一个不同的加密值每加密相同的值:
Encryption:
加密:
public static string Encrypt(string clearText)
{
byte[] clearBytes = Encoding.Unicode.GetBytes(clearText);
using (Aes encryptor = Aes.Create())
{
byte[] IV = new byte[15];
rand.NextBytes(IV);
Rfc2898DeriveBytes pdb = new Rfc2898DeriveBytes(EncryptionKey, IV);
encryptor.Key = pdb.GetBytes(32);
encryptor.IV = pdb.GetBytes(16);
using (MemoryStream ms = new MemoryStream())
{
using (CryptoStream cs = new CryptoStream(ms, encryptor.CreateEncryptor(), CryptoStreamMode.Write))
{
cs.Write(clearBytes, 0, clearBytes.Length);
cs.Close();
}
clearText = Convert.ToBase64String(IV) + Convert.ToBase64String(ms.ToArray());
}
}
return clearText;
}
Decryption:
解密:
public static string Decrypt(string cipherText)
{
byte[] IV = Convert.FromBase64String(cipherText.Substring(0, 20));
cipherText = cipherText.Substring(20).Replace(" ", "+");
byte[] cipherBytes = Convert.FromBase64String(cipherText);
using (Aes encryptor = Aes.Create())
{
Rfc2898DeriveBytes pdb = new Rfc2898DeriveBytes(EncryptionKey, IV);
encryptor.Key = pdb.GetBytes(32);
encryptor.IV = pdb.GetBytes(16);
using (MemoryStream ms = new MemoryStream())
{
using (CryptoStream cs = new CryptoStream(ms, encryptor.CreateDecryptor(), CryptoStreamMode.Write))
{
cs.Write(cipherBytes, 0, cipherBytes.Length);
cs.Close();
}
cipherText = Encoding.Unicode.GetString(ms.ToArray());
}
}
return cipherText;
}
Replace EncryptionKey with your key. In my implementation, the key is being saved in the configuration file (web.config\app.config) as you shouldn't save it hard coded. The configuration file should be also encrypted so the key won't be saved as clear text in it.
用密钥替换EncryptionKey。在我的实现中，密钥被保存在配置文件(web.config\app.config)中，因为您不应该将其硬编码。配置文件也应该加密，这样密钥就不会作为明文保存在其中。
protected static string _Key = "";
protected static string EncryptionKey
{
get
{
if (String.IsNullOrEmpty(_Key))
{
_Key = ConfigurationManager.AppSettings["AESKey"].ToString();
}
return _Key;
}
}
#7
10
Encryption
加密
public string EncryptString(string inputString)
{
MemoryStream memStream = null;
try
{
byte[] key = { };
byte[] IV = { 12, 21, 43, 17, 57, 35, 67, 27 };
string encryptKey = "aXb2uy4z"; // MUST be 8 characters
key = Encoding.UTF8.GetBytes(encryptKey);
byte[] byteInput = Encoding.UTF8.GetBytes(inputString);
DESCryptoServiceProvider provider = new DESCryptoServiceProvider();
memStream = new MemoryStream();
ICryptoTransform transform = provider.CreateEncryptor(key, IV);
CryptoStream cryptoStream = new CryptoStream(memStream, transform, CryptoStreamMode.Write);
cryptoStream.Write(byteInput, 0, byteInput.Length);
cryptoStream.FlushFinalBlock();
}
catch (Exception ex)
{
Response.Write(ex.Message);
}
return Convert.ToBase64String(memStream.ToArray());
}
Decryption:
解密:
public string DecryptString(string inputString)
{
MemoryStream memStream = null;
try
{
byte[] key = { };
byte[] IV = { 12, 21, 43, 17, 57, 35, 67, 27 };
string encryptKey = "aXb2uy4z"; // MUST be 8 characters
key = Encoding.UTF8.GetBytes(encryptKey);
byte[] byteInput = new byte[inputString.Length];
byteInput = Convert.FromBase64String(inputString);
DESCryptoServiceProvider provider = new DESCryptoServiceProvider();
memStream = new MemoryStream();
ICryptoTransform transform = provider.CreateDecryptor(key, IV);
CryptoStream cryptoStream = new CryptoStream(memStream, transform, CryptoStreamMode.Write);
cryptoStream.Write(byteInput, 0, byteInput.Length);
cryptoStream.FlushFinalBlock();
}
catch (Exception ex)
{
Response.Write(ex.Message);
}
Encoding encoding1 = Encoding.UTF8;
return encoding1.GetString(memStream.ToArray());
}
#8
5
With the reference of Encrypt and Decrypt a String in c#, I found one of good solution :
参考c#中对字符串的加密和解密，我找到了一个很好的解决方案:
static readonly string PasswordHash = "P@@Sw0rd";
static readonly string SaltKey = "S@LT&KEY";
static readonly string VIKey = "@1B2c3D4e5F6g7H8";
For Encrypt
对于加密
public static string Encrypt(string plainText)
{
byte[] plainTextBytes = Encoding.UTF8.GetBytes(plainText);
byte[] keyBytes = new Rfc2898DeriveBytes(PasswordHash, Encoding.ASCII.GetBytes(SaltKey)).GetBytes(256 / 8);
var symmetricKey = new RijndaelManaged() { Mode = CipherMode.CBC, Padding = PaddingMode.Zeros };
var encryptor = symmetricKey.CreateEncryptor(keyBytes, Encoding.ASCII.GetBytes(VIKey));
byte[] cipherTextBytes;
using (var memoryStream = new MemoryStream())
{
using (var cryptoStream = new CryptoStream(memoryStream, encryptor, CryptoStreamMode.Write))
{
cryptoStream.Write(plainTextBytes, 0, plainTextBytes.Length);
cryptoStream.FlushFinalBlock();
cipherTextBytes = memoryStream.ToArray();
cryptoStream.Close();
}
memoryStream.Close();
}
return Convert.ToBase64String(cipherTextBytes);
}
For Decrypt
对解密
public static string Decrypt(string encryptedText)
{
byte[] cipherTextBytes = Convert.FromBase64String(encryptedText);
byte[] keyBytes = new Rfc2898DeriveBytes(PasswordHash, Encoding.ASCII.GetBytes(SaltKey)).GetBytes(256 / 8);
var symmetricKey = new RijndaelManaged() { Mode = CipherMode.CBC, Padding = PaddingMode.None };
var decryptor = symmetricKey.CreateDecryptor(keyBytes, Encoding.ASCII.GetBytes(VIKey));
var memoryStream = new MemoryStream(cipherTextBytes);
var cryptoStream = new CryptoStream(memoryStream, decryptor, CryptoStreamMode.Read);
byte[] plainTextBytes = new byte[cipherTextBytes.Length];
int decryptedByteCount = cryptoStream.Read(plainTextBytes, 0, plainTextBytes.Length);
memoryStream.Close();
cryptoStream.Close();
return Encoding.UTF8.GetString(plainTextBytes, 0, decryptedByteCount).TrimEnd("\0".ToCharArray());
}
#9
4
To support mattmanser answer. Here's an example using MachineKey class to encrypt/decrypt URL safe values.
支持mattmanser回答。这里有一个使用MachineKey类加密/解密URL安全值的示例。
Something to bear in mind, as mentioned before, this will use Machine config settings (https://msdn.microsoft.com/en-us/library/ff649308.aspx). You can set encryption and decryption key/algorithm manually (you might need this specially if your site is running on multiple servers) in web.config file. You can generate keys from IIS (see here: https://blogs.msdn.microsoft.com/vijaysk/2009/05/13/iis-7-tip-10-you-can-generate-machine-keys-from-the-iis-manager/) or can use an online machine key generator like: http://www.developerfusion.com/tools/generatemachinekey/
请记住，如前所述，这将使用机器配置设置(https://msdn.microsoft.com/en-us/library/ff649308.aspx)。您可以在web中手动设置加密和解密密钥/算法(如果您的站点在多个服务器上运行，您可能尤其需要这个)。配置文件。您可以从IIS生成密钥(参见这里:https://blogs.msdn.microsoft.com/vijaysk/2009/05/13/iis-7-tip-10- can-generate-machine- keys-fromiismanager/)，也可以使用在线机器密钥生成器，如:http://www.developerfusion.com/tools/generatemachinekey/
private static readonly UTF8Encoding Encoder = new UTF8Encoding();
public static string Encrypt(string unencrypted)
{
if (string.IsNullOrEmpty(unencrypted))
return string.Empty;
try
{
var encryptedBytes = MachineKey.Protect(Encoder.GetBytes(unencrypted));
if (encryptedBytes != null && encryptedBytes.Length > 0)
return HttpServerUtility.UrlTokenEncode(encryptedBytes);
}
catch (Exception)
{
return string.Empty;
}
return string.Empty;
}
public static string Decrypt(string encrypted)
{
if (string.IsNullOrEmpty(encrypted))
return string.Empty;
try
{
var bytes = HttpServerUtility.UrlTokenDecode(encrypted);
if (bytes != null && bytes.Length > 0)
{
var decryptedBytes = MachineKey.Unprotect(bytes);
if(decryptedBytes != null && decryptedBytes.Length > 0)
return Encoder.GetString(decryptedBytes);
}
}
catch (Exception)
{
return string.Empty;
}
return string.Empty;
}
#10
3
Here is a simple example of encrypting strings in C# using AES CBC mode with random IV and HMAC and password-derived keys, to show the basic moving parts:
这里有一个简单的例子，它使用AES CBC模式，使用AES CBC模式，使用随机的IV和HMAC和密码派生的密钥对字符串进行加密，以显示基本的移动部分:
private byte[] EncryptBytes(byte[] key, byte[] plaintext)
{
using (var cipher = new RijndaelManaged { Key = key })
{
using (var encryptor = cipher.CreateEncryptor())
{
var ciphertext = encryptor.TransformFinalBlock(plaintext, 0, plaintext.Length);
// IV is prepended to ciphertext
return cipher.IV.Concat(ciphertext).ToArray();
}
}
}
private byte[] DecryptBytes(byte[] key, byte[] packed)
{
using (var cipher = new RijndaelManaged { Key = key })
{
int ivSize = cipher.BlockSize / 8;
cipher.IV = packed.Take(ivSize).ToArray();
using (var encryptor = cipher.CreateDecryptor())
{
return encryptor.TransformFinalBlock(packed, ivSize, packed.Length - ivSize);
}
}
}
private byte[] AddMac(byte[] key, byte[] data)
{
using (var hmac = new HMACSHA256(key))
{
var macBytes = hmac.ComputeHash(data);
// HMAC is appended to data
return data.Concat(macBytes).ToArray();
}
}
private bool BadMac(byte[] found, byte[] computed)
{
int mismatch = 0;
// Aim for consistent timing regardless of inputs
for (int i = 0; i < found.Length; i++)
{
mismatch += found[i] == computed[i] ? 0 : 1;
}
return mismatch != 0;
}
private byte[] RemoveMac(byte[] key, byte[] data)
{
using (var hmac = new HMACSHA256(key))
{
int macSize = hmac.HashSize / 8;
var packed = data.Take(data.Length - macSize).ToArray();
var foundMac = data.Skip(packed.Length).ToArray();
var computedMac = hmac.ComputeHash(packed);
if (this.BadMac(foundMac, computedMac))
{
throw new Exception("Bad MAC");
}
return packed;
}
}
private List<byte[]> DeriveTwoKeys(string password)
{
var salt = new byte[] { 1, 2, 3, 4, 5, 6, 7, 8 };
var kdf = new Rfc2898DeriveBytes(password, salt, 10000);
var bytes = kdf.GetBytes(32); // Two keys 128 bits each
return new List<byte[]> { bytes.Take(16).ToArray(), bytes.Skip(16).ToArray() };
}
public byte[] EncryptString(string password, String message)
{
var keys = this.DeriveTwoKeys(password);
var plaintext = Encoding.UTF8.GetBytes(message);
var packed = this.EncryptBytes(keys[0], plaintext);
return this.AddMac(keys[1], packed);
}
public String DecryptString(string password, byte[] secret)
{
var keys = this.DeriveTwoKeys(password);
var packed = this.RemoveMac(keys[1], secret);
var plaintext = this.DecryptBytes(keys[0], packed);
return Encoding.UTF8.GetString(plaintext);
}
public void Example()
{
var password = "correcthorsebatterystaple";
var secret = this.EncryptString(password, "Hello World");
Console.WriteLine("secret: " + BitConverter.ToString(secret));
var recovered = this.DecryptString(password, secret);
Console.WriteLine(recovered);
}
#11
3
If you got here looking for PGP encryption, in the following comment on an example of how to use PGP encryption via BouncyCastle, the PGPEncryptDecrypt class seems to work basically out of the box:
如果您在这里寻找PGP加密，以下是关于如何通过BouncyCastle使用PGP加密的示例的评论，那么PGPEncryptDecrypt类似乎基本上是开箱即用的:
http://blogs.microsoft.co.il/kim/2009/01/23/pgp-zip-encrypted-files-with-c/#comment-611002
http://blogs.microsoft.co.il/kim/2009/01/23/pgp-zip-encrypted-files-with-c/评论- 611002
Too long to paste here, slightly modified: https://gist.github.com/zaus/c0ea1fd8dad5d9590af1
在这里粘贴太长了，稍微修改一下:https://gist.github.com/zaus/c0ea1fd8dad5d9590af1
#12
3
An alternative to BouncyCastle for AES-GCM encryption is libsodium-net. It wraps the libsodium C library. One nice advantage is that it uses the AES-NI extension in CPUs for very fast encryption. The down side is that it won't work at all if the CPU doesn't have the extension. There's no software fall back.
用于AES-GCM加密的BouncyCastle的另一种选择是libsodium-net。它封装了lib钠C库。一个很好的优点是它使用cpu中的AES-NI扩展来进行非常快速的加密。缺点是，如果CPU没有扩展，它根本就不能工作。没有软件可以退回。
#13
2
This is the class that was placed here by Brett. However I made a slight edit since I was receiving the error 'Invalid length for a Base-64 char array' when using it for URL strings to encrypt and decrypt.
这是布雷特布置的课程。然而，我做了一个轻微的编辑，因为我在使用URL字符串加密和解密时收到了错误“Base-64 char数组的无效长度”。
public class CryptoURL
{
private static byte[] _salt = Encoding.ASCII.GetBytes("Catto_Salt_Enter_Any_Value99");
/// <summary>
/// Encrypt the given string using AES. The string can be decrypted using
/// DecryptStringAES(). The sharedSecret parameters must match.
/// The SharedSecret for the Password Reset that is used is in the next line
/// string sharedSecret = "OneUpSharedSecret9";
/// </summary>
/// <param name="plainText">The text to encrypt.</param>
/// <param name="sharedSecret">A password used to generate a key for encryption.</param>
public static string EncryptString(string plainText, string sharedSecret)
{
if (string.IsNullOrEmpty(plainText))
throw new ArgumentNullException("plainText");
if (string.IsNullOrEmpty(sharedSecret))
throw new ArgumentNullException("sharedSecret");
string outStr = null; // Encrypted string to return
RijndaelManaged aesAlg = null; // RijndaelManaged object used to encrypt the data.
try
{
// generate the key from the shared secret and the salt
Rfc2898DeriveBytes key = new Rfc2898DeriveBytes(sharedSecret, _salt);
// Create a RijndaelManaged object
aesAlg = new RijndaelManaged();
aesAlg.Key = key.GetBytes(aesAlg.KeySize / 8);
// Create a decryptor to perform the stream transform.
ICryptoTransform encryptor = aesAlg.CreateEncryptor(aesAlg.Key, aesAlg.IV);
// Create the streams used for encryption.
using (MemoryStream msEncrypt = new MemoryStream())
{
// prepend the IV
msEncrypt.Write(BitConverter.GetBytes(aesAlg.IV.Length), 0, sizeof(int));
msEncrypt.Write(aesAlg.IV, 0, aesAlg.IV.Length);
using (CryptoStream csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write))
{
using (StreamWriter swEncrypt = new StreamWriter(csEncrypt))
{
//Write all data to the stream.
swEncrypt.Write(plainText);
}
}
outStr = HttpServerUtility.UrlTokenEncode(msEncrypt.ToArray());
//outStr = Convert.ToBase64String(msEncrypt.ToArray());
// you may need to add a reference. right click reference in solution explorer => "add Reference" => .NET tab => select "System.Web"
}
}
finally
{
// Clear the RijndaelManaged object.
if (aesAlg != null)
aesAlg.Clear();
}
// Return the encrypted bytes from the memory stream.
return outStr;
}
/// <summary>
/// Decrypt the given string. Assumes the string was encrypted using
/// EncryptStringAES(), using an identical sharedSecret.
/// </summary>
/// <param name="cipherText">The text to decrypt.</param>
/// <param name="sharedSecret">A password used to generate a key for decryption.</param>
public static string DecryptString(string cipherText, string sharedSecret)
{
if (string.IsNullOrEmpty(cipherText))
throw new ArgumentNullException("cipherText");
if (string.IsNullOrEmpty(sharedSecret))
throw new ArgumentNullException("sharedSecret");
// Declare the RijndaelManaged object
// used to decrypt the data.
RijndaelManaged aesAlg = null;
// Declare the string used to hold
// the decrypted text.
string plaintext = null;
byte[] inputByteArray;
try
{
// generate the key from the shared secret and the salt
Rfc2898DeriveBytes key = new Rfc2898DeriveBytes(sharedSecret, _salt);
// Create the streams used for decryption.
//byte[] bytes = Convert.FromBase64String(cipherText);
inputByteArray = HttpServerUtility.UrlTokenDecode(cipherText);
using (MemoryStream msDecrypt = new MemoryStream(inputByteArray))
{
// Create a RijndaelManaged object
// with the specified key and IV.
aesAlg = new RijndaelManaged();
aesAlg.Key = key.GetBytes(aesAlg.KeySize / 8);
// Get the initialization vector from the encrypted stream
aesAlg.IV = ReadByteArray(msDecrypt);
// Create a decrytor to perform the stream transform.
ICryptoTransform decryptor = aesAlg.CreateDecryptor(aesAlg.Key, aesAlg.IV);
using (CryptoStream csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read))
{
using (StreamReader srDecrypt = new StreamReader(csDecrypt))
// Read the decrypted bytes from the decrypting stream
// and place them in a string.
plaintext = srDecrypt.ReadToEnd();
}
}
}
catch (System.Exception ex)
{
return "ERROR";
//throw ex;
}
finally
{
// Clear the RijndaelManaged object.
if (aesAlg != null)
aesAlg.Clear();
}
return plaintext;
}
static string ConvertStringArrayToString(string[] array)
{
//
// Concatenate all the elements into a StringBuilder.
//
StringBuilder builder = new StringBuilder();
foreach (string value in array)
{
builder.Append(value);
builder.Append('.');
}
return builder.ToString();
}
private static byte[] ReadByteArray(Stream s)
{
byte[] rawLength = new byte[sizeof(int)];
if (s.Read(rawLength, 0, rawLength.Length) != rawLength.Length)
{
throw new SystemException("Stream did not contain properly formatted byte array");
}
byte[] buffer = new byte[BitConverter.ToInt32(rawLength, 0)];
if (s.Read(buffer, 0, buffer.Length) != buffer.Length)
{
throw new SystemException("Did not read byte array properly");
}
return buffer;
}
}
#14
1
Encryption is a very common matter in programming. I think it is better to install a package to do the task for you. Maybe a simple open source Nuget project like Simple Aes Encryption
加密是编程中很常见的事情。我认为最好是安装一个包来帮你完成这个任务。也许是一个简单的开源Nuget项目，比如简单的Aes加密
The key is in the config file and therefore it is easy to change in the production environment, and I don't see any drawbacks
关键是在配置文件中，因此很容易在生产环境中更改，我没有看到任何缺陷
<MessageEncryption>
<EncryptionKey KeySize="256" Key="3q2+796tvu/erb7v3q2+796tvu/erb7v3q2+796tvu8="/>
</MessageEncryption>
#15
0
Copied in my answer here from a similar question: Simple two-way encryption for C#.
我在这里的答案来自一个类似的问题:c#的简单双向加密。
Based on multiple answers and comments.
基于多个答案和评论。
- Random initialization vector prepended to crypto text (@jbtule)
- 随机初始化向量预置到加密文本(@jbtule)
- Use TransformFinalBlock() instead of MemoryStream (@RenniePet)
- 使用TransformFinalBlock()而不是MemoryStream (@RenniePet)
- No pre-filled keys to avoid anyone copy & pasting a disaster
- 没有预先填充的键可以避免任何人复制粘贴灾难
- Proper dispose and using patterns
- 正确的配置和使用模式
Code:
代码:
/// <summary>
/// Simple encryption/decryption using a random initialization vector
/// and prepending it to the crypto text.
/// </summary>
/// <remarks>Based on multiple answers in https://*.com/questions/165808/simple-two-way-encryption-for-c-sharp </remarks>
public class SimpleAes : IDisposable
{
/// <summary>
/// Initialization vector length in bytes.
/// </summary>
private const int IvBytes = 16;
/// <summary>
/// Must be exactly 16, 24 or 32 characters long.
/// </summary>
private static readonly byte[] Key = Convert.FromBase64String("FILL ME WITH 16, 24 OR 32 CHARS");
private readonly UTF8Encoding _encoder;
private readonly ICryptoTransform _encryptor;
private readonly RijndaelManaged _rijndael;
public SimpleAes()
{
_rijndael = new RijndaelManaged {Key = Key};
_rijndael.GenerateIV();
_encryptor = _rijndael.CreateEncryptor();
_encoder = new UTF8Encoding();
}
public string Decrypt(string encrypted)
{
return _encoder.GetString(Decrypt(Convert.FromBase64String(encrypted)));
}
public void Dispose()
{
_rijndael.Dispose();
_encryptor.Dispose();
}
public string Encrypt(string unencrypted)
{
return Convert.ToBase64String(Encrypt(_encoder.GetBytes(unencrypted)));
}
private byte[] Decrypt(byte[] buffer)
{
// IV is prepended to cryptotext
byte[] iv = buffer.Take(IvBytes).ToArray();
using (ICryptoTransform decryptor = _rijndael.CreateDecryptor(_rijndael.Key, iv))
{
return decryptor.TransformFinalBlock(buffer, IvBytes, buffer.Length - IvBytes);
}
}
private byte[] Encrypt(byte[] buffer)
{
// Prepend cryptotext with IV
byte[] inputBuffer = _rijndael.IV.Concat(buffer).ToArray();
return _encryptor.TransformFinalBlock(inputBuffer, IvBytes, buffer.Length);
}
}
#16
0
Here is simple Snippet originally by ASP Snippets
以下是最初由ASP片段组成的简单代码片段
using System.Text;
using System.Security.Cryptography;
using System.IO;
private string Encrypt(string clearText)
{
string EncryptionKey = "yourkey";
byte[] clearBytes = Encoding.Unicode.GetBytes(clearText);
using (Aes encryptor = Aes.Create())
{
Rfc2898DeriveBytes pdb = new Rfc2898DeriveBytes(EncryptionKey, new byte[] { 0x49, 0x76, 0x61, 0x6e, 0x20, 0x4d, 0x65, 0x64, 0x76, 0x65, 0x64, 0x65, 0x76 });
encryptor.Key = pdb.GetBytes(32);
encryptor.IV = pdb.GetBytes(16);
using (MemoryStream ms = new MemoryStream())
{
using (CryptoStream cs = new CryptoStream(ms, encryptor.CreateEncryptor(), CryptoStreamMode.Write))
{
cs.Write(clearBytes, 0, clearBytes.Length);
cs.Close();
}
clearText = Convert.ToBase64String(ms.ToArray());
}
}
return clearText;
}
private string Decrypt(string cipherText)
{
string EncryptionKey = "yourkey";
cipherText = cipherText.Replace(" ", "+");
byte[] cipherBytes = Convert.FromBase64String(cipherText);
using (Aes encryptor = Aes.Create())
{
Rfc2898DeriveBytes pdb = new Rfc2898DeriveBytes(EncryptionKey, new byte[] { 0x49, 0x76, 0x61, 0x6e, 0x20, 0x4d, 0x65, 0x64, 0x76, 0x65, 0x64, 0x65, 0x76 });
encryptor.Key = pdb.GetBytes(32);
encryptor.IV = pdb.GetBytes(16);
using (MemoryStream ms = new MemoryStream())
{
using (CryptoStream cs = new CryptoStream(ms, encryptor.CreateDecryptor(), CryptoStreamMode.Write))
{
cs.Write(cipherBytes, 0, cipherBytes.Length);
cs.Close();
}
cipherText = Encoding.Unicode.GetString(ms.ToArray());
}
}
return cipherText;
}
#17
0
AES Algorithm:
AES算法:
public static class CryptographyProvider
{
public static string EncryptString(string plainText, out string Key)
{
if (plainText == null || plainText.Length <= 0)
throw new ArgumentNullException("plainText");
using (Aes _aesAlg = Aes.Create())
{
Key = Convert.ToBase64String(_aesAlg.Key);
ICryptoTransform _encryptor = _aesAlg.CreateEncryptor(_aesAlg.Key, _aesAlg.IV);
using (MemoryStream _memoryStream = new MemoryStream())
{
_memoryStream.Write(_aesAlg.IV, 0, 16);
using (CryptoStream _cryptoStream = new CryptoStream(_memoryStream, _encryptor, CryptoStreamMode.Write))
{
using (StreamWriter _streamWriter = new StreamWriter(_cryptoStream))
{
_streamWriter.Write(plainText);
}
return Convert.ToBase64String(_memoryStream.ToArray());
}
}
}
}
public static string DecryptString(string cipherText, string Key)
{
if (string.IsNullOrEmpty(cipherText))
throw new ArgumentNullException("cipherText");
if (string.IsNullOrEmpty(Key))
throw new ArgumentNullException("Key");
string plaintext = null;
byte[] _initialVector = new byte[16];
byte[] _Key = Convert.FromBase64String(Key);
byte[] _cipherTextBytesArray = Convert.FromBase64String(cipherText);
byte[] _originalString = new byte[_cipherTextBytesArray.Length - 16];
Array.Copy(_cipherTextBytesArray, 0, _initialVector, 0, _initialVector.Length);
Array.Copy(_cipherTextBytesArray, 16, _originalString, 0, _cipherTextBytesArray.Length - 16);
using (Aes _aesAlg = Aes.Create())
{
_aesAlg.Key = _Key;
_aesAlg.IV = _initialVector;
ICryptoTransform decryptor = _aesAlg.CreateDecryptor(_aesAlg.Key, _aesAlg.IV);
using (MemoryStream _memoryStream = new MemoryStream(_originalString))
{
using (CryptoStream _cryptoStream = new CryptoStream(_memoryStream, decryptor, CryptoStreamMode.Read))
{
using (StreamReader _streamReader = new StreamReader(_cryptoStream))
{
plaintext = _streamReader.ReadToEnd();
}
}
}
}
return plaintext;
}
}
#18
-1
A good algorithm to securely hash data is BCrypt:
一种安全哈希数据的好算法是BCrypt:
Besides incorporating a salt to protect against rainbow table attacks, bcrypt is an adaptive function: over time, the iteration count can be increased to make it slower, so it remains resistant to brute-force search attacks even with increasing computation power.
bcrypt是一种自适应功能，除了加入盐来防止彩虹表攻击外，还可以增加迭代次数，使其变慢，因此即使计算能力增加，也能抵抗蛮力搜索攻击。
There's a nice .NET implementation of BCrypt that is available also as a NuGet package.
BCrypt有一个很好的。net实现，也可以作为NuGet包使用。
#19
-2
using System;
using System.Collections.Generic;
using System.Text;
using System.Text.RegularExpressions; // This is for password validation
using System.Security.Cryptography;
using System.Configuration; // This is where the hash functions reside
namespace BullyTracker.Common
{
public class HashEncryption
{
//public string GenerateHashvalue(string thisPassword)
//{
// MD5CryptoServiceProvider md5 = new MD5CryptoServiceProvider();
// byte[] tmpSource;
// byte[] tmpHash;
// tmpSource = ASCIIEncoding.ASCII.GetBytes(thisPassword); // Turn password into byte array
// tmpHash = md5.ComputeHash(tmpSource);
// StringBuilder sOutput = new StringBuilder(tmpHash.Length);
// for (int i = 0; i < tmpHash.Length; i++)
// {
// sOutput.Append(tmpHash[i].ToString("X2")); // X2 formats to hexadecimal
// }
// return sOutput.ToString();
//}
//public Boolean VerifyHashPassword(string thisPassword, string thisHash)
//{
// Boolean IsValid = false;
// string tmpHash = GenerateHashvalue(thisPassword); // Call the routine on user input
// if (tmpHash == thisHash) IsValid = true; // Compare to previously generated hash
// return IsValid;
//}
public string GenerateHashvalue(string toEncrypt, bool useHashing)
{
byte[] keyArray;
byte[] toEncryptArray = UTF8Encoding.UTF8.GetBytes(toEncrypt);
System.Configuration.AppSettingsReader settingsReader = new AppSettingsReader();
// Get the key from config file
string key = (string)settingsReader.GetValue("SecurityKey", typeof(String));
//System.Windows.Forms.MessageBox.Show(key);
if (useHashing)
{
MD5CryptoServiceProvider hashmd5 = new MD5CryptoServiceProvider();
keyArray = hashmd5.ComputeHash(UTF8Encoding.UTF8.GetBytes(key));
hashmd5.Clear();
}
else
keyArray = UTF8Encoding.UTF8.GetBytes(key);
TripleDESCryptoServiceProvider tdes = new TripleDESCryptoServiceProvider();
tdes.Key = keyArray;
tdes.Mode = CipherMode.ECB;
tdes.Padding = PaddingMode.PKCS7;
ICryptoTransform cTransform = tdes.CreateEncryptor();
byte[] resultArray = cTransform.TransformFinalBlock(toEncryptArray, 0, toEncryptArray.Length);
tdes.Clear();
return Convert.ToBase64String(resultArray, 0, resultArray.Length);
}
/// <summary>
/// DeCrypt a string using dual encryption method. Return a DeCrypted clear string
/// </summary>
/// <param name="cipherString">encrypted string</param>
/// <param name="useHashing">Did you use hashing to encrypt this data? pass true is yes</param>
/// <returns></returns>
public string Decrypt(string cipherString, bool useHashing)
{
byte[] keyArray;
byte[] toEncryptArray = Convert.FromBase64String(cipherString);
System.Configuration.AppSettingsReader settingsReader = new AppSettingsReader();
//Get your key from config file to open the lock!
string key = (string)settingsReader.GetValue("SecurityKey", typeof(String));
if (useHashing)
{
MD5CryptoServiceProvider hashmd5 = new MD5CryptoServiceProvider();
keyArray = hashmd5.ComputeHash(UTF8Encoding.UTF8.GetBytes(key));
hashmd5.Clear();
}
else
keyArray = UTF8Encoding.UTF8.GetBytes(key);
TripleDESCryptoServiceProvider tdes = new TripleDESCryptoServiceProvider();
tdes.Key = keyArray;
tdes.Mode = CipherMode.ECB;
tdes.Padding = PaddingMode.PKCS7;
ICryptoTransform cTransform = tdes.CreateDecryptor();
byte[] resultArray = cTransform.TransformFinalBlock(toEncryptArray, 0, toEncryptArray.Length);
tdes.Clear();
return UTF8Encoding.UTF8.GetString(resultArray);
}
}
}
#20
-2
for simplicity i made for myself this function that i use for non crypto purposes : replace "yourpassphrase" with your password ...
为了简单起见，我为自己创建了一个用于非加密目的的函数:用密码替换“yourpassphrase”……
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Security.Cryptography;
using System.IO;
namespace My
{
public class strCrypto
{
// This constant string is used as a "salt" value for the PasswordDeriveBytes function calls.
// This size of the IV (in bytes) must = (keysize / 8). Default keysize is 256, so the IV must be
// 32 bytes long. Using a 16 character string here gives us 32 bytes when converted to a byte array.
private const string initVector = "r5dm5fgm24mfhfku";
private const string passPhrase = "yourpassphrase"; // email password encryption password
// This constant is used to determine the keysize of the encryption algorithm.
private const int keysize = 256;
public static string encryptString(string plainText)
{
//if the plaintext is empty or null string just return an empty string
if (plainText == "" || plainText == null )
{
return "";
}
byte[] initVectorBytes = Encoding.UTF8.GetBytes(initVector);
byte[] plainTextBytes = Encoding.UTF8.GetBytes(plainText);
PasswordDeriveBytes password = new PasswordDeriveBytes(passPhrase, null);
byte[] keyBytes = password.GetBytes(keysize / 8);
RijndaelManaged symmetricKey = new RijndaelManaged();
symmetricKey.Mode = CipherMode.CBC;
ICryptoTransform encryptor = symmetricKey.CreateEncryptor(keyBytes, initVectorBytes);
MemoryStream memoryStream = new MemoryStream();
CryptoStream cryptoStream = new CryptoStream(memoryStream, encryptor, CryptoStreamMode.Write);
cryptoStream.Write(plainTextBytes, 0, plainTextBytes.Length);
cryptoStream.FlushFinalBlock();
byte[] cipherTextBytes = memoryStream.ToArray();
memoryStream.Close();
cryptoStream.Close();
return Convert.ToBase64String(cipherTextBytes);
}
public static string decryptString(string cipherText)
{
//if the ciphertext is empty or null string just return an empty string
if (cipherText == "" || cipherText == null )
{
return "";
}
byte[] initVectorBytes = Encoding.ASCII.GetBytes(initVector);
byte[] cipherTextBytes = Convert.FromBase64String(cipherText);
PasswordDeriveBytes password = new PasswordDeriveBytes(passPhrase, null);
byte[] keyBytes = password.GetBytes(keysize / 8);
RijndaelManaged symmetricKey = new RijndaelManaged();
symmetricKey.Mode = CipherMode.CBC;
ICryptoTransform decryptor = symmetricKey.CreateDecryptor(keyBytes, initVectorBytes);
MemoryStream memoryStream = new MemoryStream(cipherTextBytes);
CryptoStream cryptoStream = new CryptoStream(memoryStream, decryptor, CryptoStreamMode.Read);
byte[] plainTextBytes = new byte[cipherTextBytes.Length];
int decryptedByteCount = cryptoStream.Read(plainTextBytes, 0, plainTextBytes.Length);
memoryStream.Close();
cryptoStream.Close();
return Encoding.UTF8.GetString(plainTextBytes, 0, decryptedByteCount);
}
}
}
}
#21
-3
I want to give you my contribute, with my code for AES Rfc2898DeriveBytes (here the documentation) algorhytm, written in C# (.NET framework 4) and fully working also for limited platforms, as .NET Compact Framework for Windows Phone 7.0+ (not all platforms support every criptographic method of the .NET framework!).
我想向您提供我的贡献，以及用c#(这里是文档)编写的AES Rfc2898DeriveBytes (algorhytm)代码。NET framework 4)以及完全适用于有限的平台，如。NET Compact framework for Windows Phone 7.0+(并不是所有平台都支持。NET framework的所有criptographic方法!)
I hope this can help anyone!
我希望这能帮助任何人!
using System;
using System.IO;
using System.Security.Cryptography;
using System.Text;
public static class Crypto
{
private static readonly byte[] IVa = new byte[] { 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x11, 0x11, 0x12, 0x13, 0x14, 0x0e, 0x16, 0x17 };
public static string Encrypt(this string text, string salt)
{
try
{
using (Aes aes = new AesManaged())
{
Rfc2898DeriveBytes deriveBytes = new Rfc2898DeriveBytes(Encoding.UTF8.GetString(IVa, 0, IVa.Length), Encoding.UTF8.GetBytes(salt));
aes.Key = deriveBytes.GetBytes(128 / 8);
aes.IV = aes.Key;
using (MemoryStream encryptionStream = new MemoryStream())
{
using (CryptoStream encrypt = new CryptoStream(encryptionStream, aes.CreateEncryptor(), CryptoStreamMode.Write))
{
byte[] cleanText = Encoding.UTF8.GetBytes(text);
encrypt.Write(cleanText, 0, cleanText.Length);
encrypt.FlushFinalBlock();
}
byte[] encryptedData = encryptionStream.ToArray();
string encryptedText = Convert.ToBase64String(encryptedData);
return encryptedText;
}
}
}
catch
{
return String.Empty;
}
}
public static string Decrypt(this string text, string salt)
{
try
{
using (Aes aes = new AesManaged())
{
Rfc2898DeriveBytes deriveBytes = new Rfc2898DeriveBytes(Encoding.UTF8.GetString(IVa, 0, IVa.Length), Encoding.UTF8.GetBytes(salt));
aes.Key = deriveBytes.GetBytes(128 / 8);
aes.IV = aes.Key;
using (MemoryStream decryptionStream = new MemoryStream())
{
using (CryptoStream decrypt = new CryptoStream(decryptionStream, aes.CreateDecryptor(), CryptoStreamMode.Write))
{
byte[] encryptedData = Convert.FromBase64String(text);
decrypt.Write(encryptedData, 0, encryptedData.Length);
decrypt.Flush();
}
byte[] decryptedData = decryptionStream.ToArray();
string decryptedText = Encoding.UTF8.GetString(decryptedData, 0, decryptedData.Length);
return decryptedText;
}
}
}
catch
{
return String.Empty;
}
}
}
}
#22
-4
using System;
using System.Data;
using System.Configuration;
using System.Text;
using System.Security.Cryptography;
namespace Encription
{
class CryptorEngine
{
public static string Encrypt(string ToEncrypt, bool useHasing)
{
byte[] keyArray;
byte[] toEncryptArray = UTF8Encoding.UTF8.GetBytes(ToEncrypt);
//System.Configuration.AppSettingsReader settingsReader = new AppSettingsReader();
string Key = "Bhagwati";
if (useHasing)
{
MD5CryptoServiceProvider hashmd5 = new MD5CryptoServiceProvider();
keyArray = hashmd5.ComputeHash(UTF8Encoding.UTF8.GetBytes(Key));
hashmd5.Clear();
}
else
{
keyArray = UTF8Encoding.UTF8.GetBytes(Key);
}
TripleDESCryptoServiceProvider tDes = new TripleDESCryptoServiceProvider();
tDes.Key = keyArray;
tDes.Mode = CipherMode.ECB;
tDes.Padding = PaddingMode.PKCS7;
ICryptoTransform cTransform = tDes.CreateEncryptor();
byte[] resultArray = cTransform.TransformFinalBlock(toEncryptArray, 0, toEncryptArray.Length);
tDes.Clear();
return Convert.ToBase64String(resultArray, 0, resultArray.Length);
}
public static string Decrypt(string cypherString, bool useHasing)
{
byte[] keyArray;
byte[] toDecryptArray = Convert.FromBase64String(cypherString);
//byte[] toEncryptArray = Convert.FromBase64String(cypherString);
//System.Configuration.AppSettingsReader settingReader = new AppSettingsReader();
string key = "Bhagwati";
if (useHasing)
{
MD5CryptoServiceProvider hashmd = new MD5CryptoServiceProvider();
keyArray = hashmd.ComputeHash(UTF8Encoding.UTF8.GetBytes(key));
hashmd.Clear();
}
else
{
keyArray = UTF8Encoding.UTF8.GetBytes(key);
}
TripleDESCryptoServiceProvider tDes = new TripleDESCryptoServiceProvider();
tDes.Key = keyArray;
tDes.Mode = CipherMode.ECB;
tDes.Padding = PaddingMode.PKCS7;
ICryptoTransform cTransform = tDes.CreateDecryptor();
try
{
byte[] resultArray = cTransform.TransformFinalBlock(toDecryptArray, 0, toDecryptArray.Length);
tDes.Clear();
return UTF8Encoding.UTF8.GetString(resultArray,0,resultArray.Length);
}
catch (Exception ex)
{
throw ex;
}
}
}
}
#23
-4
You have to use the namespace using System.Security.Cryptography; and useHashing is a bool type either true or false. String variable "key" should be same for Encryption and for Decryption
必须使用System.Security.Cryptography来使用名称空间;而useHashing是一个bool类型，要么是真，要么是假。字符串变量“key”对于加密和解密应该是相同的
//Encryption
public string EncryptText(string toEncrypt, bool useHashing)
{
try
{
byte[] keyArray;
byte[] toEncryptArray = UTF8Encoding.UTF8.GetBytes(toEncrypt);
string key = "String Key Value"; //Based on this key stirng is encrypting
//System.Windows.Forms.MessageBox.Show(key);
//If hashing use get hashcode regards to your key
if (useHashing)
{
MD5CryptoServiceProvider hashmd5 = new MD5CryptoServiceProvider();
keyArray = hashmd5.ComputeHash(UTF8Encoding.UTF8.GetBytes(key));
//Always release the resources and flush data
//of the Cryptographic service provide. Best Practice
hashmd5.Clear();
}
else
keyArray = UTF8Encoding.UTF8.GetBytes(key);
TripleDESCryptoServiceProvider tdes = new TripleDESCryptoServiceProvider();
//set the secret key for the tripleDES algorithm
tdes.Key = keyArray;
//mode of operation. there are other 4 modes. We choose ECB(Electronic code Book)
tdes.Mode = CipherMode.ECB;
//padding mode(if any extra byte added)
tdes.Padding = PaddingMode.PKCS7;
ICryptoTransform cTransform = tdes.CreateEncryptor();
//transform the specified region of bytes array to resultArray
byte[] resultArray = cTransform.TransformFinalBlock(toEncryptArray, 0, toEncryptArray.Length);
//Release resources held by TripleDes Encryptor
tdes.Clear();
//Return the encrypted data into unreadable string format
return Convert.ToBase64String(resultArray, 0, resultArray.Length);
}
catch (Exception e)
{
throw e;
}
}
//Decryption
public string DecryptText(string cipherString, bool useHashing)
{
try
{
byte[] keyArray;
//get the byte code of the string
byte[] toEncryptArray = Convert.FromBase64String(cipherString);
string key = "String Key Value"; //Based on this key string is decrypted
if (useHashing)
{
//if hashing was used get the hash code with regards to your key
MD5CryptoServiceProvider hashmd5 = new MD5CryptoServiceProvider();
keyArray = hashmd5.ComputeHash(UTF8Encoding.UTF8.GetBytes(key));
//release any resource held by the MD5CryptoServiceProvider
hashmd5.Clear();
}
else
{
//if hashing was not implemented get the byte code of the key
keyArray = UTF8Encoding.UTF8.GetBytes(key);
}
TripleDESCryptoServiceProvider tdes = new TripleDESCryptoServiceProvider();
//set the secret key for the tripleDES algorithm
tdes.Key = keyArray;
//mode of operation. there are other 4 modes.
//We choose ECB(Electronic code Book)
tdes.Mode = CipherMode.ECB;
//padding mode(if any extra byte added)
tdes.Padding = PaddingMode.PKCS7;
ICryptoTransform cTransform = tdes.CreateDecryptor();
byte[] resultArray = cTransform.TransformFinalBlock
(toEncryptArray, 0, toEncryptArray.Length);
//Release resources held by TripleDes Encryptor
tdes.Clear();
//return the Clear decrypted TEXT
return UTF8Encoding.UTF8.GetString(resultArray);
}
catch (Exception ex)
{
throw ex;
}
}