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/*
* $Id: md5.c,v 1.3 2003/06/23 19:02:38 katzj Exp $ * * 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. * * Modified 12 June 2003 Jeremy Katz <katzj@redhat.com> to handle * endianness better * */
#include <string.h>
#include <endian.h>
#include "md5.h"
void MD5_Transform(uint32 *buf, uint32 const *in);
#define IS_BIG_ENDIAN() (__BYTE_ORDER == __BIG_ENDIAN)
#define IS_LITTLE_ENDIAN() (__BYTE_ORDER == __LITTLE_ENDIAN)
static void byteReverse(unsigned char *buf, unsigned longs);
#ifndef ASM_MD5
/*
* Note: this code is harmless on little-endian machines. */static void byteReverse(unsigned char *buf, unsigned longs){ uint32 t; do { t = (uint32) ((unsigned) buf[3] << 8 | buf[2]) << 16 | ((unsigned) buf[1] << 8 | buf[0]); *(uint32 *) buf = t; buf += 4; } while (--longs);}#endif
/*
* Start MD5 accumulation. Set bit count to 0 and buffer to mysterious * initialization constants. */void MD5_Init(struct MD5Context *ctx){ ctx->buf[0] = 0x67452301U; ctx->buf[1] = 0xefcdab89U; ctx->buf[2] = 0x98badcfeU; ctx->buf[3] = 0x10325476U;
ctx->bits[0] = 0; ctx->bits[1] = 0;
if (IS_BIG_ENDIAN()) ctx->doByteReverse = 1; else ctx->doByteReverse = 0;}
/*
* Update context to reflect the concatenation of another buffer full * of bytes. */void MD5_Update(struct MD5Context *ctx, unsigned const char *buf, unsigned len){ uint32 t;
/* Update bitcount */
t = ctx->bits[0]; if ((ctx->bits[0] = t + ((uint32) len << 3)) < t) ctx->bits[1]++; /* Carry from low to high */ ctx->bits[1] += len >> 29;
t = (t >> 3) & 0x3f; /* Bytes already in shsInfo->data */
/* Handle any leading odd-sized chunks */
if (t) { unsigned char *p = (unsigned char *) ctx->in + t;
t = 64 - t; if (len < t) { memcpy(p, buf, len); return; } memcpy(p, buf, t); if (ctx->doByteReverse) byteReverse(ctx->in, 16); MD5_Transform(ctx->buf, (uint32 *) ctx->in); buf += t; len -= t; } /* Process data in 64-byte chunks */
while (len >= 64) { memcpy(ctx->in, buf, 64); if (ctx->doByteReverse) byteReverse(ctx->in, 16); MD5_Transform(ctx->buf, (uint32 *) ctx->in); buf += 64; len -= 64; }
/* Handle any remaining bytes of data. */
memcpy(ctx->in, buf, len);}
/*
* Final wrapup - pad to 64-byte boundary with the bit pattern * 1 0* (64-bit count of bits processed, MSB-first) */void MD5_Final(unsigned char digest[16], struct MD5Context *ctx){ unsigned count; unsigned char *p;
/* Compute number of bytes mod 64 */ count = (ctx->bits[0] >> 3) & 0x3F;
/* Set the first char of padding to 0x80. This is safe since there is
always at least one byte free */ p = ctx->in + count; *p++ = 0x80;
/* Bytes of padding needed to make 64 bytes */ count = 64 - 1 - count;
/* Pad out to 56 mod 64 */ if (count < 8) { /* Two lots of padding: Pad the first block to 64 bytes */ memset(p, 0, count); if (ctx->doByteReverse) byteReverse(ctx->in, 16); MD5_Transform(ctx->buf, (uint32 *) ctx->in);
/* Now fill the next block with 56 bytes */ memset(ctx->in, 0, 56); } else { /* Pad block to 56 bytes */ memset(p, 0, count - 8); } if (ctx->doByteReverse) byteReverse(ctx->in, 14);
/* Append length in bits and transform */ ((uint32 *) ctx->in)[14] = ctx->bits[0]; ((uint32 *) ctx->in)[15] = ctx->bits[1];
MD5_Transform(ctx->buf, (uint32 *) ctx->in); if (ctx->doByteReverse) byteReverse((unsigned char *) ctx->buf, 4); memcpy(digest, ctx->buf, 16); memset(ctx, 0, sizeof(ctx)); /* In case it's sensitive */}
#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, data, s) \
( w += f(x, y, z) + data, w = w<<s | w>>(32-s), w += 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 MD5_Transform(uint32 buf[4], uint32 const in[16]){ register uint32 a, b, c, d;
a = buf[0]; b = buf[1]; c = buf[2]; d = buf[3];
MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478U, 7); MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756U, 12); MD5STEP(F1, c, d, a, b, in[2] + 0x242070dbU, 17); MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceeeU, 22); MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0fafU, 7); MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62aU, 12); MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613U, 17); MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501U, 22); MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8U, 7); MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7afU, 12); MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1U, 17); MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7beU, 22); MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122U, 7); MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193U, 12); MD5STEP(F1, c, d, a, b, in[14] + 0xa679438eU, 17); MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821U, 22);
MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562U, 5); MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340U, 9); MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51U, 14); MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aaU, 20); MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105dU, 5); MD5STEP(F2, d, a, b, c, in[10] + 0x02441453U, 9); MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681U, 14); MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8U, 20); MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6U, 5); MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6U, 9); MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87U, 14); MD5STEP(F2, b, c, d, a, in[8] + 0x455a14edU, 20); MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905U, 5); MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8U, 9); MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9U, 14); MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8aU, 20);
MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942U, 4); MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681U, 11); MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122U, 16); MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380cU, 23); MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44U, 4); MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9U, 11); MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60U, 16); MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70U, 23); MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6U, 4); MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127faU, 11); MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085U, 16); MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05U, 23); MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039U, 4); MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5U, 11); MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8U, 16); MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665U, 23);
MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244U, 6); MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97U, 10); MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7U, 15); MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039U, 21); MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3U, 6); MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92U, 10); MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47dU, 15); MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1U, 21); MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4fU, 6); MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0U, 10); MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314U, 15); MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1U, 21); MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82U, 6); MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235U, 10); MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bbU, 15); MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391U, 21);
buf[0] += a; buf[1] += b; buf[2] += c; buf[3] += d;}
#endif
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