Home | Mirror | SearchITEYE 博客 | OSChina 博客 | 51CTO 博客

7.4. Java MD5

1.2版之前的JDK沒有實現md5;


/************************************************
MD5 算法的Java Bean
@author:Topcat Tuppin
Last Modified:10,Mar,2001
*************************************************/
package netkiller.security;
import java.lang.reflect.*;
/*************************************************
md5 類實現了RSA Data Security, Inc.在提交給IETF
的RFC1321中的MD5 message-digest 算法。
*************************************************/

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,切能在同一個進程空間內的多個
       Instance間共享*/

        static final int S11 = 7;
        static final int S12 = 12;
        static final int S13 = 17;
        static final int S14 = 22;

        static final int S21 = 5;
        static final int S22 = 9;
        static final int S23 = 14;
        static final int S24 = 20;

        static final int S31 = 4;
        static final int S32 = 11;
        static final int S33 = 16;
        static final int S34 = 23;

        static final int S41 = 6;
        static final int S42 = 10;
        static final int S43 = 15;
        static final int S44 = 21;



        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個核心數據,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 (lsb first)
        private byte[] buffer = new byte[64]; // input buffer

       /* digestHexStr是MD5的唯一一個公共成員,是最新一次計算結果的
         16進制ASCII表示.
       */

        public String digestHexStr;

        /* digest,是最新一次計算結果的2進制內部表示,表示128bit的MD5值. */

        private byte[] digest = new byte[16];

       /*
         getMD5ofStr是類MD5最主要的公共方法,入口參數是你想要進行MD5變換的字元串
         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();

                digestHexStr = "";

                for (int i = 0; i < 16; i++) {

                        digestHexStr += byteHEX(digest[i]);

                }

                return digestHexStr;



        }

        // 這是MD5這個類的標準建構子,JavaBean要求有一個public的並且沒有參數的建構子

        public MD5() {
                md5Init();
                return;
        }

        /* md5Init是一個初始化函數,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函數,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宏,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將調用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
         函數由getMD5ofStr調用,調用之前需要調用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數組的塊拷貝函數,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核心變換程序,有md5Update調用,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數組按順序拆成byte數組,因為java的long類型是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數組按順序合成成long數組,因為java的long類型是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"程序,因為java沒有unsigned運算
        */

        public static long 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)

       */

        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;

        }



        public String getMD5String(String md5){
                      return getMD5ofStr(md5).toLowerCase();
        }

        public static void main(String args[]) {

                MD5 m = new MD5();

                if (Array.getLength(args) == 0) {   //如果沒有參數,執行標準的Test Suite



                    System.out.println("MD5 Test suite:");

                       System.out.println("MD5(\"\"):"+m.getMD5ofStr(""));

                       System.out.println("MD5(\"a\"):"+m.getMD5ofStr("a"));

                       System.out.println("MD5(\"abc\"):"+m.getMD5ofStr("abc"));

                       System.out.println("MD5(\"message digest\"):"+m.getMD5ofStr("message digest"));

                       System.out.println("MD5(\"abcdefghijklmnopqrstuvwxyz\"):"+

                        m.getMD5ofStr("abcdefghijklmnopqrstuvwxyz"));

                       System.out.println("MD5(\"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789\"):"+

                            m.getMD5ofStr("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"));

                }

                else

                          System.out.println("MD5(" + args[0] + ")=" + m.getMD5ofStr(args[0]));





        }



}

			

以下使用JDK 1.5.x版實現;


import java.security.*;

public class md5Test {

	private static String dumpBytes(byte[] bytes) {
	    int i;
	    StringBuffer sb = new StringBuffer();
	    for (i = 0; i < bytes.length; i++) {
	      if (i % 32 == 0 && i != 0) {
	        sb.append("\n");
	      }
	      String s = Integer.toHexString(bytes[i]);
	      if (s.length() < 2) {
	        s = "0" + s;
	      }
	      if (s.length() > 2) {
	        s = s.substring(s.length() - 2);
	      }
	      sb.append(s);
	    }
	    return sb.toString();
	}
	public static void main(String[] args) {

		String passwd = "netkiller";
	    MessageDigest md = null;
		try {
			md = MessageDigest.getInstance("MD5");
			md.update("chen".getBytes());
		} catch (NoSuchAlgorithmException e) {
			e.printStackTrace();
		}

	    System.out.println(dumpBytes(md.digest()));
	}

}

			

編譯運行,輸入字元串:a1a8887793acfc199182a649e905daab

comments powered by Disqus