md5.c
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上传日期:2007-01-08
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文件大小:7k
- #pragma ident "@(#)md5.c 1.3 95/11/18 Sun Microsystems"
- /*
- * This code implements the MD5 message-digest algorithm.
- * The algorithm is due to Ron Rivest. This code was
- * written by Colin Plumb in 1993, no copyright is claimed.
- * This code is in the public domain; do with it what you wish.
- *
- * Equivalent code is available from RSA Data Security, Inc.
- * This code has been tested against that, and is equivalent,
- * except that you don't need to include two pages of legalese
- * with every copy.
- *
- * To compute the message digest of a chunk of bytes, declare an
- * MD5Context structure, pass it to MD5Init, call MD5Update as
- * needed on buffers full of bytes, and then call MD5Final, which
- * will fill a supplied 16-byte array with the digest.
- */
- typedef unsigned char byte;
- #include "md5.h"
- #if (!defined (_KERNEL) && !defined(KERNEL))
- #define BCOPY(s,d,n) memcpy(d,s,n)
- #define BZERO(s,n) memset(s,0,n)
- #else
- #define BCOPY(s,d,n) bcopy(s,d,n)
- #define BZERO(s,n) bzero(s,n)
- #endif
- #ifndef ASM_MD5
- /*
- * Shuffle the bytes into little-endian order within words, as per the
- * MD5 spec. Note: this code works regardless of the byte order.
- */
- void
- byteSwap(word32 *buf, unsigned words)
- {
- byte *p = (byte *)buf;
- do {
- *buf++ = (word32)((unsigned)p[3] << 8 | p[2]) << 16 |
- ((unsigned)p[1] << 8 | p[0]);
- p += 4;
- } while (--words);
- }
- #endif
- /*
- * Start MD5 accumulation. Set bit count to 0 and buffer to mysterious
- * initialization constants.
- */
- void
- xMD5Init(struct xMD5Context *ctx)
- {
- ctx->buf[0] = 0x67452301;
- ctx->buf[1] = 0xefcdab89;
- ctx->buf[2] = 0x98badcfe;
- ctx->buf[3] = 0x10325476;
- ctx->bytes[0] = 0;
- ctx->bytes[1] = 0;
- }
- /*
- * Update context to reflect the concatenation of another buffer full
- * of bytes.
- */
- void
- xMD5Update(struct xMD5Context *ctx, byte const *buf, size_t len)
- {
- word32 t;
- /* Update byte count */
- t = ctx->bytes[0];
- if ((ctx->bytes[0] = t + len) < t)
- ctx->bytes[1]++; /* Carry from low to high */
- t = 64 - (t & 0x3f); /* Space available in ctx->in (at least 1) */
- if ((unsigned)t > len) {
- BCOPY(buf, (byte *)ctx->in + 64 - (unsigned)t, len);
- return;
- }
- /* First chunk is an odd size */
- BCOPY(buf,(byte *)ctx->in + 64 - (unsigned)t, (unsigned)t);
- byteSwap(ctx->in, 16);
- xMD5Transform(ctx->buf, ctx->in);
- buf += (unsigned)t;
- len -= (unsigned)t;
- /* Process data in 64-byte chunks */
- while (len >= 64) {
- BCOPY(buf, ctx->in, 64);
- byteSwap(ctx->in, 16);
- xMD5Transform(ctx->buf, ctx->in);
- buf += 64;
- len -= 64;
- }
- /* Handle any remaining bytes of data. */
- BCOPY(buf, ctx->in, len);
- }
- /*
- * Final wrapup - pad to 64-byte boundary with the bit pattern
- * 1 0* (64-bit count of bits processed, MSB-first)
- */
- void
- xMD5Final(byte digest[16], struct xMD5Context *ctx)
- {
- int count = (int)(ctx->bytes[0] & 0x3f); /* Bytes in ctx->in */
- byte *p = (byte *)ctx->in + count; /* First unused byte */
- /* Set the first char of padding to 0x80. There is always room. */
- *p++ = 0x80;
- /* Bytes of padding needed to make 56 bytes (-8..55) */
- count = 56 - 1 - count;
- if (count < 0) { /* Padding forces an extra block */
- BZERO(p, count+8);
- byteSwap(ctx->in, 16);
- xMD5Transform(ctx->buf, ctx->in);
- p = (byte *)ctx->in;
- count = 56;
- }
- BZERO(p, count+8);
- byteSwap(ctx->in, 14);
- /* Append length in bits and transform */
- ctx->in[14] = ctx->bytes[0] << 3;
- ctx->in[15] = ctx->bytes[1] << 3 | ctx->bytes[0] >> 29;
- xMD5Transform(ctx->buf, ctx->in);
- byteSwap(ctx->buf, 4);
- BCOPY(ctx->buf, digest, 16);
- BZERO(ctx,sizeof(ctx));
- }
- #ifndef ASM_MD5
- /* The four core functions - F1 is optimized somewhat */
- /* #define F1(x, y, z) (x & y | ~x & z) */
- #define F1(x, y, z) (z ^ (x & (y ^ z)))
- #define F2(x, y, z) F1(z, x, y)
- #define F3(x, y, z) (x ^ y ^ z)
- #define F4(x, y, z) (y ^ (x | ~z))
- /* This is the central step in the MD5 algorithm. */
- #define MD5STEP(f,w,x,y,z,in,s)
- (w += f(x,y,z) + in, w = (w<<s | w>>(32-s)) + x)
- /*
- * The core of the MD5 algorithm, this alters an existing MD5 hash to
- * reflect the addition of 16 longwords of new data. MD5Update blocks
- * the data and converts bytes into longwords for this routine.
- */
- void
- xMD5Transform(word32 buf[4], word32 const in[16])
- {
- register word32 a, b, c, d;
- a = buf[0];
- b = buf[1];
- c = buf[2];
- d = buf[3];
- MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
- MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
- MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
- MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
- MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
- MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
- MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
- MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
- MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
- MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
- MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
- MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
- MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
- MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
- MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
- MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
- MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
- MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
- MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
- MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
- MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
- MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
- MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
- MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
- MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
- MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
- MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
- MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
- MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
- MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
- MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
- MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
- MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
- MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
- MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
- MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
- MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
- MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
- MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
- MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
- MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
- MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
- MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
- MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
- MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
- MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
- MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
- MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
- MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
- MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
- MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
- MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
- MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
- MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
- MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
- MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
- MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
- MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
- MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
- MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
- MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
- MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
- MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
- MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
- buf[0] += a;
- buf[1] += b;
- buf[2] += c;
- buf[3] += d;
- }
- #endif