DES简介：
DES算法为密码*中的对称密码*，又被成为美国数据加密标准，是1972年美国IBM公司研制的对称密码*加密算法。其密钥长度为56位，明文按64位进行分组，将分组后的明文组和56位的密钥按位替代或交换的方法形成密文组的加密方法。DES加密算法特点：分组比较短、密钥太短、密码生命周期短、运算速度较慢。DES工作的基本原理是，其入口参数有三个:key、data、mode。 key为加密解密使用的密钥，data为加密解密的数据，mode为其工作模式。当模式为加密模式时，明文按照64位进行分组，形成明文组，key用于对数据加密，当模式为解密模式时，key用于对数据解密。实际运用中，密钥只用到了64位中的56位，这样才具有高的安全性。DES( Data Encryption Standard)算法，于1977年得到美国*的正式许可，是一种用56位密钥来加密64位数据的方法。虽然56位密钥的DES算法已经风光不在,而且常有用Des加密的明文被破译的报道,但是了解一下昔日美国的标准加密算法总是有益的,而且目前DES算法得到了广泛的应用,在某些场合,仍然发挥着余热。
DES加密算法代码如下：
public class DesEncrypt {
/*static final是表示了只读，切能在同一个进程空间内的多个
Instance间共享*/
// private static String strDefaultKey = "87654321";
public String digestHexStr;
//28
static final int pc_1_cp[]={
57,49,41,33,25,17,9
,1,58,50,42,34,26,18
,10,2,59,51,43,35,27
,19,11,3,60,52,44,36};
//28
static final int pc_1_dp[]={
63,55,47,39,31,23,15
,7,62,54,46,38,30,22
,14,6,61,53,45,37,29
,21,13,5,28,20,12,4};
//48
static final int pc_2p[]={
14,17,11,24,1,5,
3,28,15,6,21,10,
23,19,12,4,26,8,
16,7,27,20,13,2,
41,52,31,37,47,55,
30,40,51,45,33,48,
44,49,39,56,34,53,
46,42,50,36,29,32};
//16
static final int ls_countp[]={1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1};
//64
static final int iip_tab_p[]={
58,50,42,34,26,18,10,2,
60,52,44,36,28,20,12,4,
62,54,46,38,30,22,14,6,
64,56,48,40,32,24,16,8,
57,49,41,33,25,17,9,1,
59,51,43,35,27,19,11,3,
61,53,45,37,29,21,13,5,
63,55,47,39,31,23,15,7};
//64
static final int _iip_tab_p[]={
40,8,48,16,56,24,64,32,
39,7,47,15,55,23,63,31,
38,6,46,14,54,22,62,30,
37,5,45,13,53,21,61,29,
36,4,44,12,52,20,60,28,
35,3,43,11,51,19,59,27,
34,2,42,10,50,18,58,26,
33,1,41,9,49,17,57,25};
//48
static final int e_r_p[]={
32,1,2,3,4,5,4,5,6,7,8,9,
8,9,10,11,12,13,12,13,14,15,16,17,
16,17,18,19,20,21,20,21,22,23,24,25,
24,25,26,27,28,29,28,29,30,31,32,1};
//32
static final int local_PP[]={
16,7,20,21,29,12,28,17,
1,15,23,26,5,18,31,10,
2,8,24,14,32,27,3,9,
19,13,30,6,22,11,4,25};
//[8][4][16]
static final int ccom_SSS_p[][][]={
{{14,4,13,1,2,15,11,8,3,10,6,12,5,9,0,7},
{0,15,7,4,14,2,13,1,10,6,12,11,9,5,3,8},
{4,1,14,8,13,6,2,11,15,12,9,7,3,10,5,0},
{15,12,8,2,4,9,1,7,5,11,3,14,10,0,6,13}},
{{15,1,8,14,6,11,3,4,9,7,2,13,12,0,5,10},
{3,13,4,7,15,2,8,14,12,0,1,10,6,9,11,5},
{0,14,7,11,10,4,13,1,5,8,12,6,9,3,2,15},
{13,8,10,1,3,15,4,2,11,6,7,12,0,5,14,9}},
{{10,0,9,14,6,3,15,5,1,13,12,7,11,4,2,8},
{13,7,0,9,3,4,6,10,2,8,5,14,12,11,15,1},
{13,6,4,9,8,15,3,0,11,1,2,12,5,10,14,7},
{1,10,13,0,6,9,8,7,4,15,14,3,11,5,2,12}},
{{7,13,14,3,0,6,9,10,1,2,8,5,11,12,4,15},
{13,8,11,5,6,15,0,3,4,7,2,12,1,10,14,9},
{10,6,9,0,12,11,7,13,15,1,3,14,5,2,8,4},
{3,15,0,6,10,1,13,8,9,4,5,11,12,7,2,14}}, /* err on */
{{2,12,4,1,7,10,11,6,8,5,3,15,13,0,14,9},
{14,11,2,12,4,7,13,1,5,0,15,10,3,9,8,6}, /* err on */
{4,2,1,11,10,13,7,8,15,9,12,5,6,3,0,14},
{11,8,12,7,1,14,2,13,6,15,0,9,10,4,5,3}},
{{12,1,10,15,9,2,6,8,0,13,3,4,14,7,5,11},
{10,15,4,2,7,12,9,5,6,1,13,14,0,11,3,8},
{9,14,15,5,2,8,12,3,7,0,4,10,1,13,11,6},
{4,3,2,12,9,5,15,10,11,14,1,7,6,0,8,13}},
{{4,11,2,14,15,0,8,13,3,12,9,7,5,10,6,1},
{13,0,11,7,4,9,1,10,14,3,5,12,2,15,8,6},
{1,4,11,13,12,3,7,14,10,15,6,8,0,5,9,2},
{6,11,13,8,1,4,10,7,9,5,0,15,14,2,3,12}},
{{13,2,8,4,6,15,11,1,10,9,3,14,5,0,12,7},
{1,15,13,8,10,3,7,4,12,5,6,11,0,14,9,2},
{7,11,4,1,9,12,14,2,0,6,10,13,15,3,5,8},
{2,1,14,7,4,10,8,13,15,12,9,0,3,5,6,11}}};
byte[][] C=new byte[17][28];
byte[][] D=new byte[17][28];
byte[][] K=new byte[17][48];
public DesEncrypt() {
return;
}
/*iu2b把int转换成byte
*/
private static byte iu2b ( int input) {
byte output1;
output1 = (byte)(input & 0xff);
return output1;
}
/*
b2iu把byte按照不考虑正负号的原则的＂升位＂成int程序，
因为java没有unsigned运算
*/
private static int b2iu(byte b) {
return b < 0 ? b & 0x7F + 128 : b;
}
/*byteHEX()，用来把一个byte类型的数转换成十六进制的ASCII表示，
因为java中的byte的toString无法实现这一点，我们又没有C语言中的
sprintf(outbuf,"%02X",ib)
*/
public static String byteHEX(byte ib) {
char[] Digit = { '0','1','2','3','4','5','6','7','8','9', 'A','B','C','D','E','F' };
char[] ob = new char[2];
ob[0] = Digit[(ib >>> 4) & 0X0F];
ob[1] = Digit[ib & 0X0F];
String s = new String(ob);
return s;
}
/* desMemcpy是一个内部使用的byte数组的块拷贝函数，
从input的inpos开始把len长度的
字节拷贝到output的outpos位置开始
*/
private void desMemcpy (byte[] output, byte[] input, int outpos, int inpos, int len) {
int i;
for (i = 0; i < len; i++)
output[outpos + i] = input[inpos + i];
}
private void Fexpand0(byte[] in,byte[] out) {
int divide;
int i,j;
byte temp1;
for (i=0;i<8;i++)
{
divide=7;
for (j=0;j<8;j++)
{
temp1=in[i];
out[8*i+j]=iu2b((b2iu(temp1)>>>divide)&1);
divide--;
}
}
}
private void FLS(byte[] bits,byte[] buffer,int count) {
int i,j;
for (i=0;i<28;i++)
{
buffer[i]=bits[(i+count)%28];
}
}
private void Fson(byte[] cc,byte[] dd,byte[] kk) {
int i,j;
byte[] buffer=new byte[56];
for (i=0;i<28;i++)
buffer[i]=cc[i];
for (i=28;i<56;i++)
buffer[i]=dd[i-28];
for (i=0;i<48;i++)
kk[i]=buffer[pc_2p[i]-1];
}
private void Fsetkeystar(byte[] bits) {
int i,j;
for (i=0;i<28;i++)
C[0][i]=bits[pc_1_cp[i]-1];
for (i=0;i<28;i++)
D[0][i]=bits[pc_1_dp[i]-1];
for (j=0;j<16;j++)
{
FLS(C[j],C[j+1],ls_countp[j]);
FLS(D[j],D[j+1],ls_countp[j]);
Fson(C[j+1],D[j+1],K[j+1]);
}
}
private void Fiip(byte[] text,byte[] ll,byte[] rr) {
int i,j;
byte[] buffer=new byte[64];
byte[] tmp=new byte[64];
Fexpand0(text,buffer);
for (i=0;i<32;i++)
ll[i]=buffer[iip_tab_p[i]-1];
for (i=0;i<32;i++)
rr[i]=buffer[iip_tab_p[i+32]-1];
}
private void Fs_box(byte[] aa,byte[] bb) {
int i,j,k,m;
int y,z;
byte[] ss=new byte[8];
m=0;
for (i=0;i<8;i++)
{
j=6*i;
y=b2iu(aa[j])*2+b2iu(aa[j+5]);
z=b2iu(aa[j+1])*8+b2iu(aa[j+2])*4+b2iu(aa[j+3])*2+b2iu(aa[j+4]);
ss[i]=iu2b(ccom_SSS_p[i][y][z]);
y=3;
for (k=0;k<4;k++)
{
bb[m++]=iu2b((b2iu(ss[i])>>>y)&1);
y--;
}
}
}
private void FF(int n,byte[] ll,byte[] rr,byte[] LL,byte[] RR) {
int i,j;
byte[] buffer=new byte[64],tmp=new byte[64];
for (i=0;i<48;i++)
buffer[i]=rr[e_r_p[i]-1];
for (i=0;i<48;i++)
buffer[i]=iu2b((b2iu(buffer[i])+b2iu(K[n][i]))&1);
Fs_box(buffer,tmp);
for (i=0;i<32;i++)
buffer[i]=tmp[local_PP[i]-1];
for (i=0;i<32;i++)
RR[i]=iu2b((b2iu(buffer[i])+b2iu(ll[i]))&1);
for (i=0;i<32;i++)
LL[i]=rr[i];
}
private void _Fiip(byte[] text,byte[] ll,byte[] rr) {
int i,j;
byte[] tmp=new byte[64];
for (i=0;i<32;i++)
tmp[i]=ll[i];
for (i=32;i<64;i++)
tmp[i]=rr[i-32];
for (i=0;i<64;i++)
text[i]=tmp[_iip_tab_p[i]-1];
}
private void Fcompress016(byte[] out,byte[] in) {
int times;
int i,j;
for (i=0;i<16;i++)
{
times=3;
in[i]='0';
for (j=0;j<4;j++)
{
in[i]=iu2b(b2iu(in[i])+(b2iu(out[i*16+j])<<times));
times--;
}
}
}
void Fcompress0(byte[] out,byte[] in) {
int times;
int i,j;
for (i=0;i<8;i++)
{
times=7;
in[i]=0;
for (j=0;j<8;j++)
{
in[i]=iu2b(b2iu(in[i])+(b2iu(out[i*8+j])<<times));
times--;
}
}
}
private void Fencrypt0(byte[] text,byte[] mtext) {
byte[] ll=new byte[64],rr=new byte[64],LL=new byte[64],RR=new byte[64];
byte[] tmp=new byte[64];
int i,j;
Fiip(text,ll,rr);
for (i=1;i<17;i++)
{
FF(i,ll,rr,LL,RR);
for (j=0;j<32;j++)
{
ll[j]=LL[j];
rr[j]=RR[j];
}
}
_Fiip(tmp,rr,ll);
Fcompress0(tmp,mtext);
}
private void FDES(byte[] key,byte[] text,byte[] mtext) {
byte[] tmp=new byte[64];
Fexpand0(key,tmp);
Fsetkeystar(tmp);
Fencrypt0(text,mtext);
}
/*加密*/
public int ENCRYPT(byte[] key, byte[] s,byte[] d,int len ) {
int i,j;
byte[] cData=new byte[8];
byte[] cEncryptData=new byte[8];
for (i=0;i<len;i+=8) {
if ((i+8)>len) {
desMemcpy(cData,s,0,i,len-i);
for (j = len-i; j < 8; j++)
cData[j] = 0;
} else
desMemcpy(cData,s,0,i,8);
FDES(key,cData,cEncryptData);
desMemcpy(d,cEncryptData,i,0,8);
}
return i;
}
private void Fdiscrypt0(byte[] mtext,byte[] text) {
byte[] ll=new byte[64],rr=new byte[64],LL=new byte[64],RR=new byte[64];
byte[] tmp=new byte[64];
int i,j;
Fiip(mtext,ll,rr);
for (i=16;i>0;i--)
{
FF(i,ll,rr,LL,RR);
for (j=0;j<32;j++)
{
ll[j]=LL[j];
rr[j]=RR[j];
}
}
_Fiip(tmp,rr,ll);
Fcompress0(tmp,text);
}
/*****************************************************************************
* function: DES
* parameter: u_char * key ; key for encrypt
* u_char * mtext ; encipher data
* u_char * text ; plain data
* return: none
*****************************************************************************/
private void _FDES(byte[] key,byte[] mtext,byte[] text) {
byte[] tmp=new byte[64];
Fexpand0(key,tmp);
Fsetkeystar(tmp);
Fdiscrypt0(mtext,text);
}
/*解密*/
public int DECRYPT(byte[] key, byte[] s,byte[] d,int len ) {
int i;
byte[] cData=new byte[8];
byte[] cEncryptData=new byte[8];
for(i=0;i<len;i+=8) {
desMemcpy(cEncryptData,d,0,i,8);
_FDES(key,cEncryptData,cData);
desMemcpy(s,cData,i,0,8);
}
return i;
}
public static byte[] hexStr2ByteArr(String strIn) {
byte[] arrB = strIn.getBytes();
int iLen = arrB.length;
//两个字符表示一个字节，所以字节数组长度是字符串长度除以2
byte[] arrOut = new byte[iLen / 2];
for (int i = 0; i < iLen; i = i + 2) {
String strTmp = new String(arrB, i, 2);
arrOut[i / 2] = (byte) Integer.parseInt(strTmp, 16);
}
return arrOut;
}
}
3DES简介
密码学中，3DES（或称为Triple DES）是三重数据加密算法（TDEA，Triple Data Encryption Algorithm）块密码的通称。它相当于是对每个数据块应用三次DES加密算法。由于计算机运算能力的增强，原版DES密码的密钥长度变得容易被暴力破解；3DES即是设计用来提供一种相对简单的方法，即通过增加DES的密钥长度来避免类似的攻击，而不是设计一种全新的块密码算法。