md5 support

depending on CONFIG_SMALL this can either be compiled to a fully unrolled kernel / rfc reference style md5 routine
or a single loop similar to what mplayer uses

Originally committed as revision 5565 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavutil/md5.c

+/*
+ * Copyright (C) 2006 Michael Niedermayer (michaelni@gmx.at)
+ * Copyright (C) 2003-2005 by Christopher R. Hertel (crh@ubiqx.mn.org)
+ * #inlcude LGPL license
+ *
+ * References:
+ *  IETF RFC 1321: The MD5 Message-Digest Algorithm
+ *       Ron Rivest. IETF, April, 1992
+ *
+ * based on http://ubiqx.org/libcifs/source/Auth/MD5.c
+ *          from Christopher R. Hertel (crh@ubiqx.mn.org)
+ * simplified, cleaned and IMO redundant comments removed by michael
+ *
+ * if you use gcc, then version 4.1 or later and -fomit-frame-pointer is
+ * strongly recommanded
+ */
+
+#include "common.h"
+#include <string.h>
+#include "md5.h"
+
+typedef struct AVMD5{
+    uint8_t  block[64];
+    uint32_t ABCD[4];
+    uint64_t len;
+    int      b_used;
+} AVMD5;
+
+const int av_md5_size= sizeof(AVMD5);
+
+static const uint8_t S[4][4] = {
+    { 7, 12, 17, 22 },  /* Round 1 */
+    { 5,  9, 14, 20 },  /* Round 2 */
+    { 4, 11, 16, 23 },  /* Round 3 */
+    { 6, 10, 15, 21 }   /* Round 4 */
+};
+
+static const uint32_t T[64] = {
+    0xd76aa478, 0xe8c7b756, 0x242070db, 0xc1bdceee,   /* Round 1 */
+    0xf57c0faf, 0x4787c62a, 0xa8304613, 0xfd469501,
+    0x698098d8, 0x8b44f7af, 0xffff5bb1, 0x895cd7be,
+    0x6b901122, 0xfd987193, 0xa679438e, 0x49b40821,
+
+    0xf61e2562, 0xc040b340, 0x265e5a51, 0xe9b6c7aa,   /* Round 2 */
+    0xd62f105d, 0x02441453, 0xd8a1e681, 0xe7d3fbc8,
+    0x21e1cde6, 0xc33707d6, 0xf4d50d87, 0x455a14ed,
+    0xa9e3e905, 0xfcefa3f8, 0x676f02d9, 0x8d2a4c8a,
+
+    0xfffa3942, 0x8771f681, 0x6d9d6122, 0xfde5380c,   /* Round 3 */
+    0xa4beea44, 0x4bdecfa9, 0xf6bb4b60, 0xbebfbc70,
+    0x289b7ec6, 0xeaa127fa, 0xd4ef3085, 0x04881d05,
+    0xd9d4d039, 0xe6db99e5, 0x1fa27cf8, 0xc4ac5665,
+
+    0xf4292244, 0x432aff97, 0xab9423a7, 0xfc93a039,   /* Round 4 */
+    0x655b59c3, 0x8f0ccc92, 0xffeff47d, 0x85845dd1,
+    0x6fa87e4f, 0xfe2ce6e0, 0xa3014314, 0x4e0811a1,
+    0xf7537e82, 0xbd3af235, 0x2ad7d2bb, 0xeb86d391,
+};
+
+#define CORE(i, a, b, c, d) \
+        t = S[i>>4][i&3];\
+        a += T[i];\
+\
+        switch(i>>4){\
+        case 0: a += (d ^ b&(c^d)) + X[      i &15 ]; break;\
+        case 1: a += (c ^ d&(c^b)) + X[ (1+5*i)&15 ]; break;\
+        case 2: a += (b^c^d)       + X[ (5+3*i)&15 ]; break;\
+        case 3: a += (c^(b|~d))    + X[ (  7*i)&15 ]; break;\
+        }\
+        a = b + (( a << t ) | ( a >> (32 - t) ));
+
+static void body(uint32_t ABCD[4], const uint32_t X[16]){
+    int i, t;
+    unsigned int a= ABCD[3];
+    unsigned int b= ABCD[2];
+    unsigned int c= ABCD[1];
+    unsigned int d= ABCD[0];
+
+#ifdef WORDS_BIGENDIAN
+    for(i=0; i<16; i++)
+        X[i]= bswap_32(X[i]);
+#endif
+
+#ifdef CONFIG_SMALL
+    for( i = 0; i < 64; i++ ){
+        CORE(i,a,b,c,d)
+        t=d; d=c; c=b; b=a; a=t;
+    }
+#else
+#define CORE2(i) CORE(i,a,b,c,d) CORE((i+1),d,a,b,c) CORE((i+2),c,d,a,b) CORE((i+3),b,c,d,a)
+#define CORE4(i) CORE2(i) CORE2((i+4)) CORE2((i+8)) CORE2((i+12))
+CORE4(0) CORE4(16) CORE4(32) CORE4(48)
+#endif
+
+    ABCD[0] += d;
+    ABCD[1] += c;
+    ABCD[2] += b;
+    ABCD[3] += a;
+}
+
+void av_md5_init(AVMD5 *ctx){
+    ctx->len    = 0;
+    ctx->b_used = 0;
+
+    ctx->ABCD[0] = 0x10325476;
+    ctx->ABCD[1] = 0x98badcfe;
+    ctx->ABCD[2] = 0xefcdab89;
+    ctx->ABCD[3] = 0x67452301;
+}
+
+void av_md5_update(AVMD5 *ctx, const uint8_t *src, const int len){
+    int i;
+
+    ctx->len += len;
+
+    for( i = 0; i < len; i++ ){
+        ctx->block[ ctx->b_used++ ] = src[i];
+        if( 64 == ctx->b_used ){
+            body(ctx->ABCD, ctx->block);
+            ctx->b_used = 0;
+        }
+    }
+}
+
+void av_md5_final(AVMD5 *ctx, uint8_t *dst){
+    int i;
+
+    ctx->block[ctx->b_used++] = 0x80;
+
+    memset(&ctx->block[ctx->b_used], 0, 64 - ctx->b_used);
+
+    if( 56 < ctx->b_used ){
+        body( ctx->ABCD, ctx->block );
+        memset(ctx->block, 0, 64);
+    }
+
+    for(i=0; i<8; i++)
+        ctx->block[56+i] = (ctx->len << 3) >> (i<<3);
+
+    body(ctx->ABCD, ctx->block);
+
+#define le2me_32(a) a
+    for(i=0; i<4; i++)
+        ((uint32_t*)dst)[i]= le2me_32(ctx->ABCD[3-i]);
+}
+
+void av_md5_sum(uint8_t *dst, const uint8_t *src, const int len){
+    AVMD5 ctx[1];
+
+    av_md5_init(ctx);
+    av_md5_update(ctx, src, len);
+    av_md5_final(ctx, dst);
+}
+
+#ifdef TEST
+#include <stdio.h>
+main(){
+    uint64_t md5val;
+    int i;
+    uint8_t in[1000];
+
+    for(i=0; i<1000; i++) in[i]= i*i;
+    av_md5_sum( (uint8_t*)&md5val, in,  1000); printf("%lld\n", md5val);
+    av_md5_sum( (uint8_t*)&md5val, in,  63); printf("%lld\n", md5val);
+    av_md5_sum( (uint8_t*)&md5val, in,  64); printf("%lld\n", md5val);
+    av_md5_sum( (uint8_t*)&md5val, in,  65); printf("%lld\n", md5val);
+    for(i=0; i<1000; i++) in[i]= i % 127;
+    av_md5_sum( (uint8_t*)&md5val, in,  999); printf("%lld\n", md5val);
+}
+#endif

libavutil/md5.h

+#ifndef MD5_H
+#define MD5_H
+
+extern const av_md5_size;
+
+struct AVMD5;
+
+void av_md5_init(struct AVMD5 *ctx);
+void av_md5_update(struct AVMD5 *ctx, const uint8_t *src, const int len);
+void av_md5_final(struct AVMD5 *ctx, uint8_t *dst);
+
+#endif /* MD5_H */
+