將資料庫中的密碼加密
package com.test.util;
/** * 使用MD5演算法對字串進行加密的工具類。 MD5即Message-Digest * Algorithm5(資訊-摘要演算法5)，是一種用於產生數字簽名的單項雜湊演算法， 這個演算法是不可逆的， * 也就是說即使你看到源程式和演算法描述，也無法將一個MD5的值變換回原始的字串 * */ public class MD5 { /* * 下面這些S11-S44實際上是一個4*4的矩陣，在原始的C實現中是用#define 實現的， 這裡把它們實現成為static * final是表示了只讀，切能在同一個程序空間內的多個 Instance間共享 */ private static final int S11 = 7;
private static final int S12 = 12;
private static final int S13 = 17;
private static final int S14 = 22;
private static final int S21 = 5;
private static final int S22 = 9;
private static final int S23 = 14;
private static final int S24 = 20;
private static final int S31 = 4;
private static final int S32 = 11;
private static final int S33 = 16;
private static final int S34 = 23;
private static final int S41 = 6;
private static final int S42 = 10;
private static final int S43 = 15;
private static final int S44 = 21;
private static final byte[] PADDING = { -128, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
/* * 下面的三個成員是MD5計算過程中用到的3個核心資料，在原始的C實現中 被定義到MD5_CTX結構中 * */ private long[] state = new long[4]; // state (ABCD)
private long[] count = new long[2];// number of bits, modulo 2^64(lsbfirst)
private byte[] buffer = new byte[64]; // input buffer
/* * digest,是最新一次計算結果的2進位制內部表示，表示128bit的MD5值. */ private byte[] digest = new byte[16];
public MD5() { md5Init(); }
/* * getMD5ofStr是類MD5最主要的公共方法，入口引數是你想要進行MD5變換的字串 * 返回的是變換完的結果，這個結果是從公共成員digestHexStr取得的． */ public String getMD5ofStr(String inbuf) { md5Init(); md5Update(inbuf.getBytes(), inbuf.length()); md5Final(); String digestHexStr = ""; for (int i = 0; i < 16; i++) { digestHexStr += byteHEX(digest[i]); } return digestHexStr;
}
/* md5Init是一個初始化函式，初始化核心變數，裝入標準的幻數 */ private void md5Init() { count[0] = 0L; count[1] = 0L; // /* Load magic initialization constants.
state[0] = 0x67452301L; state[1] = 0xefcdab89L; state[2] = 0x98badcfeL; state[3] = 0x10325476L; return; }
/* * F, G, H ,I 是4個基本的MD5函式，在原始的MD5的C實現中，由於它們是 * 簡單的位運算，可能出於效率的考慮把它們實現成了巨集，在java中，我們把它們 實現成了private方法，名字保持了原來C中的。 */
private long F(long x, long y, long z) { return (x & y) | ((~x) & z);
}
private long G(long x, long y, long z) { return (x & z) | (y & (~z));
}
private long H(long x, long y, long z) { return x ^ y ^ z; }
private long I(long x, long y, long z) { return y ^ (x | (~z)); }
/* * FF,GG,HH和II將呼叫F,G,H,I進行近一步變換 FF, GG, HH, and II transformations for * rounds 1, 2, 3, and 4. Rotation is separate from addition to prevent * recomputation. */
private long FF(long a, long b, long c, long d, long x, long s, long ac) { a += F(b, c, d) + x + ac; a = ((int) a << s) | ((int) a >>> (32 - s)); a += b; return a; }
private long GG(long a, long b, long c, long d, long x, long s, long ac) { a += G(b, c, d) + x + ac; a = ((int) a << s) | ((int) a >>> (32 - s)); a += b; return a; }
private long HH(long a, long b, long c, long d, long x, long s, long ac) { a += H(b, c, d) + x + ac; a = ((int) a << s) | ((int) a >>> (32 - s)); a += b; return a; }
private long II(long a, long b, long c, long d, long x, long s, long ac) { a += I(b, c, d) + x + ac; a = ((int) a << s) | ((int) a >>> (32 - s)); a += b; return a; }
/* * md5Update是MD5的主計算過程，inbuf是要變換的位元組串，inputlen是長度，這個 * 函式由getMD5ofStr呼叫，呼叫之前需要呼叫md5init，因此把它設計成private的 */ private void md5Update(byte[] inbuf, int inputLen) {
int i, index, partLen; byte[] block = new byte[64]; index = (int) (count[0] >>> 3) & 0x3F; // /* Update number of bits */ if ((count[0] += (inputLen << 3)) < (inputLen << 3)) count[1]++; count[1] += (inputLen >>> 29);
partLen = 64 - index;
// Transform as many times as possible. if (inputLen >= partLen) { md5Memcpy(buffer, inbuf, index, 0, partLen); md5Transform(buffer);
for (i = partLen; i + 63 < inputLen; i += 64) {
md5Memcpy(block, inbuf, 0, i, 64); md5Transform(block); } index = 0;
} else
i = 0;
// /* Buffer remaining input */ md5Memcpy(buffer, inbuf, index, i, inputLen - i);
}
/* * md5Final整理和填寫輸出結果 */ private void md5Final() { byte[] bits = new byte[8]; int index, padLen;
// /* Save number of bits */ Encode(bits, count, 8);
// /* Pad out to 56 mod 64. index = (int) (count[0] >>> 3) & 0x3f; padLen = (index < 56) ? (56 - index) : (120 - index); md5Update(PADDING, padLen);
// /* Append length (before padding) */ md5Update(bits, 8);
// /* Store state in digest */ Encode(digest, state, 16);
}
/* * md5Memcpy是一個內部使用的byte陣列的塊拷貝函式，從input的inpos開始把len長度的 * 位元組拷貝到output的outpos位置開始 */
private void md5Memcpy(byte[] output, byte[] input, int outpos, int inpos, int len) { int i;
for (i = 0; i < len; i++) output[outpos + i] = input[inpos + i]; }
/* * md5Transform是MD5核心變換程式，有md5Update呼叫，block是分塊的原始位元組 */ private void md5Transform(byte block[]) { long a = state[0], b = state[1], c = state[2], d = state[3]; long[] x = new long[16];
Decode(x, block, 64);
/* Round 1 */ a = FF(a, b, c, d, x[0], S11, 0xd76aa478L); /* 1 */ d = FF(d, a, b, c, x[1], S12, 0xe8c7b756L); /* 2 */ c = FF(c, d, a, b, x[2], S13, 0x242070dbL); /* 3 */ b = FF(b, c, d, a, x[3], S14, 0xc1bdceeeL); /* 4 */ a = FF(a, b, c, d, x[4], S11, 0xf57c0fafL); /* 5 */ d = FF(d, a, b, c, x[5], S12, 0x4787c62aL); /* 6 */ c = FF(c, d, a, b, x[6], S13, 0xa8304613L); /* 7 */ b = FF(b, c, d, a, x[7], S14, 0xfd469501L); /* 8 */ a = FF(a, b, c, d, x[8], S11, 0x698098d8L); /* 9 */ d = FF(d, a, b, c, x[9], S12, 0x8b44f7afL); /* 10 */ c = FF(c, d, a, b, x[10], S13, 0xffff5bb1L); /* 11 */ b = FF(b, c, d, a, x[11], S14, 0x895cd7beL); /* 12 */ a = FF(a, b, c, d, x[12], S11, 0x6b901122L); /* 13 */ d = FF(d, a, b, c, x[13], S12, 0xfd987193L); /* 14 */ c = FF(c, d, a, b, x[14], S13, 0xa679438eL); /* 15 */ b = FF(b, c, d, a, x[15], S14, 0x49b40821L); /* 16 */
/* Round 2 */ a = GG(a, b, c, d, x[1], S21, 0xf61e2562L); /* 17 */ d = GG(d, a, b, c, x[6], S22, 0xc040b340L); /* 18 */ c = GG(c, d, a, b, x[11], S23, 0x265e5a51L); /* 19 */ b = GG(b, c, d, a, x[0], S24, 0xe9b6c7aaL); /* 20 */ a = GG(a, b, c, d, x[5], S21, 0xd62f105dL); /* 21 */ d = GG(d, a, b, c, x[10], S22, 0x2441453L); /* 22 */ c = GG(c, d, a, b, x[15], S23, 0xd8a1e681L); /* 23 */ b = GG(b, c, d, a, x[4], S24, 0xe7d3fbc8L); /* 24 */ a = GG(a, b, c, d, x[9], S21, 0x21e1cde6L); /* 25 */ d = GG(d, a, b, c, x[14], S22, 0xc33707d6L); /* 26 */ c = GG(c, d, a, b, x[3], S23, 0xf4d50d87L); /* 27 */ b = GG(b, c, d, a, x[8], S24, 0x455a14edL); /* 28 */ a = GG(a, b, c, d, x[13], S21, 0xa9e3e905L); /* 29 */ d = GG(d, a, b, c, x[2], S22, 0xfcefa3f8L); /* 30 */ c = GG(c, d, a, b, x[7], S23, 0x676f02d9L); /* 31 */ b = GG(b, c, d, a, x[12], S24, 0x8d2a4c8aL); /* 32 */
/* Round 3 */ a = HH(a, b, c, d, x[5], S31, 0xfffa3942L); /* 33 */ d = HH(d, a, b, c, x[8], S32, 0x8771f681L); /* 34 */ c = HH(c, d, a, b, x[11], S33, 0x6d9d6122L); /* 35 */ b = HH(b, c, d, a, x[14], S34, 0xfde5380cL); /* 36 */ a = HH(a, b, c, d, x[1], S31, 0xa4beea44L); /* 37 */ d = HH(d, a, b, c, x[4], S32, 0x4bdecfa9L); /* 38 */ c = HH(c, d, a, b, x[7], S33, 0xf6bb4b60L); /* 39 */ b = HH(b, c, d, a, x[10], S34, 0xbebfbc70L); /* 40 */ a = HH(a, b, c, d, x[13], S31, 0x289b7ec6L); /* 41 */ d = HH(d, a, b, c, x[0], S32, 0xeaa127faL); /* 42 */ c = HH(c, d, a, b, x[3], S33, 0xd4ef3085L); /* 43 */ b = HH(b, c, d, a, x[6], S34, 0x4881d05L); /* 44 */ a = HH(a, b, c, d, x[9], S31, 0xd9d4d039L); /* 45 */ d = HH(d, a, b, c, x[12], S32, 0xe6db99e5L); /* 46 */ c = HH(c, d, a, b, x[15], S33, 0x1fa27cf8L); /* 47 */ b = HH(b, c, d, a, x[2], S34, 0xc4ac5665L); /* 48 */
/* Round 4 */ a = II(a, b, c, d, x[0], S41, 0xf4292244L); /* 49 */ d = II(d, a, b, c, x[7], S42, 0x432aff97L); /* 50 */ c = II(c, d, a, b, x[14], S43, 0xab9423a7L); /* 51 */ b = II(b, c, d, a, x[5], S44, 0xfc93a039L); /* 52 */ a = II(a, b, c, d, x[12], S41, 0x655b59c3L); /* 53 */ d = II(d, a, b, c, x[3], S42, 0x8f0ccc92L); /* 54 */ c = II(c, d, a, b, x[10], S43, 0xffeff47dL); /* 55 */ b = II(b, c, d, a, x[1], S44, 0x85845dd1L); /* 56 */ a = II(a, b, c, d, x[8], S41, 0x6fa87e4fL); /* 57 */ d = II(d, a, b, c, x[15], S42, 0xfe2ce6e0L); /* 58 */ c = II(c, d, a, b, x[6], S43, 0xa3014314L); /* 59 */ b = II(b, c, d, a, x[13], S44, 0x4e0811a1L); /* 60 */ a = II(a, b, c, d, x[4], S41, 0xf7537e82L); /* 61 */ d = II(d, a, b, c, x[11], S42, 0xbd3af235L); /* 62 */ c = II(c, d, a, b, x[2], S43, 0x2ad7d2bbL); /* 63 */ b = II(b, c, d, a, x[9], S44, 0xeb86d391L); /* 64 */
state[0] += a; state[1] += b; state[2] += c; state[3] += d;
}
/* * Encode把long陣列按順序拆成byte陣列，因為java的long型別是64bit的， 只拆低32bit，以適應原始C實現的用途 */ private void Encode(byte[] output, long[] input, int len) { int i, j;
for (i = 0, j = 0; j < len; i++, j += 4) { output[j] = (byte) (input[i] & 0xffL); output[j + 1] = (byte) ((input[i] >>> 8) & 0xffL); output[j + 2] = (byte) ((input[i] >>> 16) & 0xffL); output[j + 3] = (byte) ((input[i] >>> 24) & 0xffL); } }
/* * Decode把byte陣列按順序合成成long陣列，因為java的long型別是64bit的， * 只合成低32bit，高32bit清零，以適應原始C實現的用途 */ private void Decode(long[] output, byte[] input, int len) { int i, j;
for (i = 0, j = 0; j < len; i++, j += 4) output[i] = b2iu(input[j]) | (b2iu(input[j + 1]) << 8) | (b2iu(input[j + 2]) << 16) | (b2iu(input[j + 3]) << 24);
return; }
/* * b2iu是我寫的一個把byte按照不考慮正負號的原則的＂升位＂程式，因為java沒有unsigned運算 */ private static long b2iu(byte b) { return b < 0 ? b & 0x7F + 128 : b; }
/* * byteHEX()，用來把一個byte型別的數轉換成十六進位制的ASCII表示， * 因為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) */ private 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; }
public static void main(String args[]) { String source = "888888"; MD5 md5 = new MD5(); String s1 = md5.getMD5ofStr(source);// length=32 System.out.println(s1); } }