Table of Contents
MD5 為當前常用的 hash function,一般用來計算資料的雜湊值,俾利資料正確性之驗證;md5sum 則為用來檢查計算hash function 的的工具程序,具體的參數用法可去man md5sum 的用法。
生成雜湊值,有些文章叫指紋
md5sum file.txt
C:\GnuWin32\neo>md5sum file.txt 7012acbb1d394b20567dffbf0992b677 *file.txt C:\GnuWin32\neo>md5sum file.txt > file.txt.md5 C:\GnuWin32\neo>md5sum -c file.txt.md5 file.txt: OK
生成指紋並重訂向到檔案
md5sum file.txt > file.txt.md5
C:\GnuWin32\neo>md5sum file.txt 7012acbb1d394b20567dffbf0992b677 *file.txt C:\GnuWin32\neo>md5sum file.txt > file.txt.md5 C:\GnuWin32\neo>md5sum -c file.txt.md5 file.txt: OK
生成一組檔案
md5sum file0.txt > file.txt.md5 md5sum file1.txt >> file.txt.md5 md5sum file2.txt >> file.txt.md5
使用通配符
C:\GnuWin32\neo>md5sum * 7012acbb1d394b20567dffbf0992b677 *file.txt d9226d4bd8779baa69db272f89a2e05c *message.txt C:\GnuWin32\neo>md5sum * >file.txt.md5
驗證檔案是否被人更改過
md5sum -c file.txt.md5
C:\GnuWin32\neo>md5sum file.txt 7012acbb1d394b20567dffbf0992b677 *file.txt C:\GnuWin32\neo>md5sum file.txt > file.txt.md5 C:\GnuWin32\neo>md5sum -c file.txt.md5 file.txt: OK
# cat md5.php <html> <p>MD5 密碼產生器</p> <form method=post action=des.php> <p>password:<input name=passwd type=text size=20></p> <input type=submit value=submit> </form> <? $enpw=md5($passwd); echo "password is: $enpw"; ?>
select md5('password');
[chen@linux chen]$ mysql Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 11947 to server version: 4.0.13-log Type 'help;' or '\h' for help. Type '\c' to clear the buffer. mysql> select md5('chen'); +----------------------------------+ | md5('chen') | +----------------------------------+ | a1a8887793acfc199182a649e905daab | +----------------------------------+ 1 row in set (0.00 sec) mysql> mysql> select md5('chen') as passwd; +----------------------------------+ | passwd | +----------------------------------+ | a1a8887793acfc199182a649e905daab | +----------------------------------+ 1 row in set (0.00 sec) mysql>
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
# Functional style use Digest::MD5 qw(md5 md5_hex md5_base64); $digest = md5($data); $digest = md5_hex($data); $digest = md5_base64($data); # OO style use Digest::MD5; $ctx = Digest::MD5->new; $ctx->add($data); $ctx->addfile(*FILE); $digest = $ctx->digest; $digest = $ctx->hexdigest; $digest = $ctx->b64digest;