des和3Des加密算法實現

2024年1月24日 87次阅读

DES簡介：

DES算法爲密碼體制中的對稱密碼體制，又被成爲美國數據加密標準，是1972年美國IBM公司研製的對稱密碼體制加密算法。其密鑰長度爲56位，明文按64位進行分組，將分組後的明文組和56位的密鑰按位替代或交換的方法形成密文組的加密方法。DES加密算法特點：分組比較短、密鑰太短、密碼生命週期短、運算速度較慢。DES工作的基本原理是，其入口參數有三個:key、data、mode。 key爲加密解密使用的密鑰，data爲加密解密的數據，mode爲其工作模式。當模式爲加密模式時，明文按照64位進行分組，形成明文組，key用於對數據加密，當模式爲解密模式時，key用於對數據解密。實際運用中，密鑰只用到了64位中的56位，這樣才具有高的安全性。DES( Data Encryption Standard)算法，於1977年得到美國政府的正式許可，是一種用56位密鑰來加密64位數據的方法。雖然56位密鑰的DES算法已經風光不在,而且常有用Des加密的明文被破譯的報道,但是瞭解一下昔日美國的標準加密算法總是有益的,而且目前DES算法得到了廣泛的應用,在某些場合,仍然發揮着餘熱。

DES加密算法代碼如下：

public class DesEncrypt {

/*static final是表示了只讀，切能在同一個進程空間內的多個

Instance間共享*/

// 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轉換成byte

private static byte iu2b ( int input) {

byte output1;

output1 = (byte)(input & 0xff);

return output1;

}

b2iu把byte按照不考慮正負號的原則的＂升位＂成int程序，

因爲java沒有unsigned運算

private static int b2iu(byte b) {

return b < 0 ? b & 0x7F + 128 : b;

}

/*byteHEX()，用來把一個byte類型的數轉換成十六進制的ASCII表示，

　因爲java中的byte的toString無法實現這一點，我們又沒有C語言中的

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是一個內部使用的byte數組的塊拷貝函數，

從input的inpos開始把len長度的

字節拷貝到output的outpos位置開始

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;

//兩個字符表示一個字節，所以字節數組長度是字符串長度除以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簡介

密碼學中，3DES（或稱爲Triple DES）是三重數據加密算法（TDEA，Triple Data Encryption Algorithm）塊密碼的通稱。它相當於是對每個數據塊應用三次DES加密算法。由於計算機運算能力的增強，原版DES密碼的密鑰長度變得容易被暴力破解；3DES即是設計用來提供一種相對簡單的方法，即通過增加DES的密鑰長度來避免類似的攻擊，而不是設計一種全新的塊密碼算法。

3DES加密算法： package com.star.sms.business.provision.send.util.encrypt; import java.security.Key; import java.security.NoSuchAlgorithmException; import java.security.SecureRandom; import java.security.Security; import javax.crypto.Cipher; import javax.crypto.KeyGenerator; import javax.crypto.SecretKey; import javax.crypto.spec.SecretKeySpec; import com.sun.crypto.provider.SunJCE; /** * @author xuefc * @version 1.0 */ public class Des_3DesUtils { // —————————-3DES—————————- /** * 生成3DES密鑰. * * @param key_byte * seed key * @throws Exception * @return javax.crypto.SecretKey Generated DES key */ public static SecretKey genTripleDesKey(byte[] byteKey) { if (byteKey == null) { return null; } return new SecretKeySpec(byteKey, “DESede”); } public static SecretKey genTripleDesKey(String strKey) { if (strKey == null) { return null; } return genTripleDesKey(strKey.getBytes()); } /** * 3DES 解密(byte[]). * * @param key * SecretKey * @param crypt * byte[] * @throws Exception * @return byte[] */ public static byte[] tripleDesDecrypt(SecretKey key, byte[] data) { try { Cipher cipher = Cipher.getInstance(“DESede/ECB/NoPadding”); cipher.init(Cipher.DECRYPT_MODE, key); return cipher.doFinal(data); } catch (Exception e) { throw new EncryptException(e); } } /** * 3DES 解密. * 因爲3DES是對稱加密算法，key是24位，當只有16位時，後8位取key的前8位 * @param key * SecretKey * @param crypt * byte[] * @throws Exception * @return byte[] */ public static byte[] tripleDesDecrypt(byte[] byteKey, byte[] data) { byte[] keys = null; if (byteKey.length == 16) { keys = new byte[24]; System.arraycopy(byteKey, 0,keys , 0, 16); System.arraycopy(byteKey, 0,keys , 16, 8); } else { keys = byteKey; } return tripleDesDecrypt(genTripleDesKey(keys), data); } /** * 3DES加密(byte[]). * * @param key * SecretKey * @param src * byte[] * @throws Exception * @return byte[] */ public static byte[] tripleDesEncrypt(SecretKey key, byte[] data) { try { Cipher cipher = Cipher.getInstance(“DESede/ECB/NoPadding”); cipher.init(Cipher.ENCRYPT_MODE, key); return cipher.doFinal(data); } catch (Exception e) { throw new EncryptException(e); } } /** * 3DES加密(byte[]). * 因爲3DES是對稱加密算法，key是24位，當只有16位時，後8位取key的前8位 * @param key * SecretKey * @param src * byte[] * @throws Exception * @return byte[] */ public static byte[] tripleDesEncrypt(byte[] byteKey, byte[] data) { byte[] keys = null; if (byteKey.length == 16) { keys = new byte[24]; System.arraycopy(byteKey, 0,keys , 0, 16); System.arraycopy(byteKey, 0,keys , 16, 8); } else { keys = byteKey; } return tripleDesEncrypt(genTripleDesKey(keys), data); } // —————————-DES—————————- /** * 獲得DES加密的密鑰。需要JCE的支持，如果jdk版本低於1.4，則需要安裝jce-1_2_2才能正常使用。 * * @return Key 返回對稱密鑰 * @throws java.security.NoSuchAlgorithmException * @see util.EncryptUtil 其中包括加密和解密的方法 */ public static Key getDesKey(byte[] key) { if (key == null) { return null; } try { Security.insertProviderAt(new SunJCE(), 1); KeyGenerator generator = KeyGenerator.getInstance(“DES”); generator.init(new SecureRandom(key)); return generator.generateKey(); } catch (NoSuchAlgorithmException e) { throw new EncryptException(e); } } public static Key getDesKey(String key) { if (key == null) { return null; } return getDesKey(key.getBytes()); } /** * DES加密 * * @param key * 密鑰 * @param data * 需要加密的數據 * @return byte[] 加密後的數據 * @throws util.EncryptException */ public static byte[] desEncrypt(byte[] byteKey, byte[] data) { // return desEncrypt(getDesKey(byteKey), data); try { byte[] encryptData = new byte[data.length]; DesEncrypt de = new DesEncrypt(); de.ENCRYPT(byteKey, data, encryptData, data.length); return encryptData; } catch (Exception e) { throw new EncryptException(e); } } /** * DES解密 * * @param key * 密鑰 * @param raw * 待解密的數據 * @return byte[] 解密後的數據 * @throws util.EncryptException */ public static byte[] desDecrypt(byte[] byteKey, byte[] data) { // return desDecrypt(getDesKey(byteKey), data); try { byte[] plainData = new byte[data.length]; DesEncrypt de = new DesEncrypt(); de.DECRYPT(byteKey, plainData, data, data.length); return plainData; } catch (Exception e) { throw new EncryptException(e); } } public static String getHexStr(byte[] data) { if (data == null) { return “”; } StringBuffer str = new StringBuffer(); for (byte b : data) { String temp = Integer.toHexString(b & 0xFF); // str.append(“0x”); if (temp.length() == 1) { str.append(“0” + temp); } else { str.append(temp); } str.append(“,”); } return str.substring(0,str.length()-1).toString(); } } class EncryptException extends RuntimeException { private static final long serialVersionUID = 1L; public EncryptException(String msg) { } public EncryptException(Throwable e) { super(e); } }