使用MD5的ASP.NET哈希密码

I've got the following code, which hashes a password as inputted by the user, and subsequently stores it in an SQL Server database:

我有以下代码，它会记录用户输入的密码，然后将其存储在SQL Server数据库中：

   Byte[] originalPassword;
   Byte[] hashedPassword;

   MD5CryptoServiceProvider md5Hasher = new MD5CryptoServiceProvider();
   UTF8Encoding encoder = new UTF8Encoding();

   originalPassword = encoder.GetBytes(passwordBox.Text);
   hashedPassword = md5Hasher.ComputeHash(originalPassword);
   command.Parameters.Add(new SqlParameter("Password", hashedPassword));
   command.ExecuteNonQuery();

My problem is that I've got a number of plaintext passwords already stored in the database. How exactly am I to modify them into this new hashed format, since they appear as '0xA99ED....'?

我的问题是我已经在数据库中存储了许多明文密码。我究竟是如何将它们修改为这种新的哈希格式，因为它们显示为“0xA99ED ....”？

4 个解决方案

#1

The output of any hash function is a collection of bytes, not a collection of text. So when you enter text as a test you are probably entering a text conversion of that byte array. Simply converting it in SQL to a binary(16) is not correct, you need to do a proper conversion, which is something you cannot do in SQL. This also explains why changing the datatype of the column doesn't work either.

任何散列函数的输出都是字节的集合，而不是文本的集合。因此，当您输入文本作为测试时，您可能正在输入该字节数组的文本转换。简单地将它在SQL中转换为二进制（16）是不正确的，您需要进行适当的转换，这是您在SQL中无法做到的。这也解释了为什么更改列的数据类型也不起作用。

When hashes are expressed as strings it's usually via hex values of each byte, or via a character set encoder. In order to switch between them you need to figure out which one is in use and perform the conversion in code, not by switching the datatypes in SQL

当哈希表示为字符串时，它通常通过每个字节的十六进制值，或通过字符集编码器。为了在它们之间切换，您需要确定哪个正在使用并在代码中执行转换，而不是通过在SQL中切换数据类型

#2

try this out first create a Windows form with 2 buttons and 2 text boxes
1st button label Encrypt
2nd button label Validate
**--- Hashing using the MD5 class ---**

use the following code below
/// <summary>
/// take any string and encrypt it using MD5 then
/// return the encrypted data 
/// </summary>
/// <param name="data">input text you will enterd to encrypt it</param>
/// <returns>return the encrypted text as hexadecimal string</returns>
private string GetMD5HashData(string data)
{
    //create new instance of md5
    MD5 md5 = MD5.Create();

    //convert the input text to array of bytes
    byte[] hashData = md5.ComputeHash(Encoding.Default.GetBytes(data));

    //create new instance of StringBuilder to save hashed data
    StringBuilder returnValue = new StringBuilder();

    //loop for each byte and add it to StringBuilder
    for (int i = 0; i < hashData.Length; i++)
    {
        returnValue.Append(hashData[i].ToString());
    }

    // return hexadecimal string
    return returnValue.ToString();

}

/// <summary>
/// encrypt input text using MD5 and compare it with
/// the stored encrypted text
/// </summary>
/// <param name="inputData">input text you will enterd to encrypt it</param>
/// <param name="storedHashData">the encrypted text
///         stored on file or database ... etc</param>
/// <returns>true or false depending on input validation</returns>
private bool ValidateMD5HashData(string inputData, string storedHashData)
{
    //hash input text and save it string variable
    string getHashInputData = GetMD5HashData(inputData);

    if (string.Compare(getHashInputData, storedHashData) == 0)
    {
        return true;
    }
    else
    {
        return false;
    }
}

#3

This method works great, returns a string from the MD5 hash using LINQ. This worked for MailChimp API 3.0 whereas the previous code that returned the byte array did not.

此方法很有效，使用LINQ从MD5哈希返回一个字符串。这适用于MailChimp API 3.0，而之前返回字节数组的代码没有。

  public static string GetMd5HashData(string yourString )
  {
     return string.Join("", MD5.Create().ComputeHash(Encoding.ASCII.GetBytes(yourString)).Select(s => s.ToString("x2")));
  }

Found here: http://rion.io/2013/02/23/generating-an-md5-hash-from-a-string-using-linq/

在这里找到：http：//rion.io/2013/02/23/generating-an-md5-hash-from-a-string-using-linq/

#4

Here is the VB.NET version using LINQ (for those who are still using VB.NET):

这是使用LINQ的VB.NET版本（对于那些仍在使用VB.NET的人）：

Public Function GenerateMD5(ByVal plainText As String) As String
        Return String.Join("", System.Security.Cryptography.MD5.Create().ComputeHash(System.Text.Encoding.ASCII.GetBytes(plainText)).Select(Function(x) x.ToString("x2")))
End Function