Audacious  $Id:Doxyfile42802007-03-2104:39:00Znenolod$
md5.c
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00001 /*
00002  * MD5 implementation, modified for Audacious from
00003  * Colin Plumb's implementation by Matti 'ccr' Hämäläinen.
00004  *
00005  * This code implements the MD5 message-digest algorithm.
00006  * The algorithm is due to Ron Rivest.  This code was
00007  * written by Colin Plumb in 1993, no copyright is claimed.
00008  * This code is in the public domain; do with it what you wish.
00009  */
00010 #include "md5.h"
00011 #include <string.h>
00012 
00013 
00014 #if G_BYTE_ORDER == G_LITTLE_ENDIAN
00015 #  define aud_md5_bytereverse(buf, len) do { } while (0)
00016 #else
00017 #  if G_BYTE_ORDER == G_BIG_ENDIAN
00018 static void aud_md5_bytereverse(guint8 *buf, guint l)
00019 {
00020     guint32 t;
00021     do {
00022         t = (guint32) ((guint) buf[3] << 8 | buf[2]) << 16 | ((guint) buf[1] << 8 | buf[0]);
00023         *(guint32 *) buf = t;
00024         buf += sizeof(guint32);
00025     } while (--l);
00026 }
00027 #  else
00028 #    error Unsupported endianess, not G_LITTLE_ENDIAN or G_BIG_ENDIAN!
00029 #  endif
00030 #endif
00031 
00032 
00039 void aud_md5_init(aud_md5state_t *ctx)
00040 {
00041     ctx->buf[0] = 0x67452301;
00042     ctx->buf[1] = 0xefcdab89;
00043     ctx->buf[2] = 0x98badcfe;
00044     ctx->buf[3] = 0x10325476;
00045 
00046     ctx->bits[0] = 0;
00047     ctx->bits[1] = 0;
00048 }
00049 
00050 
00051 /* The core of the MD5 algorithm, this alters an existing MD5 hash to
00052  * reflect the addition of 16 longwords of new data.  aud_md5_update blocks
00053  * the data and converts bytes into longwords for this routine.
00054  */
00055 #define F1(x, y, z) (z ^ (x & (y ^ z)))
00056 #define F2(x, y, z) F1(z, x, y)
00057 #define F3(x, y, z) (x ^ y ^ z)
00058 #define F4(x, y, z) (y ^ (x | ~z))
00059 #define MD5STEP(f, w, x, y, z, data, s) \
00060     ( w += f(x, y, z) + data,  w = w<<s | w>>(32-s),  w += x )
00061 
00062 static void aud_md5_transform(guint32 buf[4], guint32 const in[16])
00063 {
00064     register guint32 a, b, c, d;
00065 
00066     a = buf[0];
00067     b = buf[1];
00068     c = buf[2];
00069     d = buf[3];
00070 
00071     MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
00072     MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
00073     MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
00074     MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
00075     MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
00076     MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
00077     MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
00078     MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
00079     MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
00080     MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
00081     MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
00082     MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
00083     MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
00084     MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
00085     MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
00086     MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
00087 
00088     MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
00089     MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
00090     MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
00091     MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
00092     MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
00093     MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
00094     MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
00095     MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
00096     MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
00097     MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
00098     MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
00099     MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
00100     MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
00101     MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
00102     MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
00103     MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
00104 
00105     MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
00106     MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
00107     MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
00108     MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
00109     MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
00110     MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
00111     MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
00112     MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
00113     MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
00114     MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
00115     MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
00116     MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
00117     MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
00118     MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
00119     MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
00120     MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
00121 
00122     MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
00123     MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
00124     MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
00125     MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
00126     MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
00127     MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
00128     MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
00129     MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
00130     MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
00131     MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
00132     MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
00133     MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
00134     MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
00135     MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
00136     MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
00137     MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
00138 
00139     buf[0] += a;
00140     buf[1] += b;
00141     buf[2] += c;
00142     buf[3] += d;
00143 }
00144 
00145 
00154 void aud_md5_append(aud_md5state_t *ctx, const guint8 *buf, guint len)
00155 {
00156     guint32 t;
00157 
00158     /* Update bitcount */
00159     t = ctx->bits[0];
00160     if ((ctx->bits[0] = t + ((guint32) len << 3)) < t)
00161         ctx->bits[1]++;    /* Carry from low to high */
00162     ctx->bits[1] += len >> 29;
00163 
00164     t = (t >> 3) & 0x3f;    /* Bytes already in shsInfo->data */
00165 
00166     /* Handle any leading odd-sized chunks */
00167     if (t) {
00168         guint8 *p = (guint8 *) ctx->in + t;
00169 
00170         t = 64 - t;
00171         if (len < t) {
00172             memcpy(p, buf, len);
00173             return;
00174         }
00175         memcpy(p, buf, t);
00176         aud_md5_bytereverse(ctx->in, 16);
00177         aud_md5_transform(ctx->buf, (guint32 *) ctx->in);
00178         buf += t;
00179         len -= t;
00180     }
00181 
00182     /* Process data in 64-byte chunks */
00183     while (len >= 64) {
00184         memcpy(ctx->in, buf, 64);
00185         aud_md5_bytereverse(ctx->in, 16);
00186         aud_md5_transform(ctx->buf, (guint32 *) ctx->in);
00187         buf += 64;
00188         len -= 64;
00189     }
00190 
00191     /* Handle any remaining bytes of data. */
00192     memcpy(ctx->in, buf, len);
00193 }
00194 
00201 void aud_md5_finish(aud_md5state_t *ctx, aud_md5hash_t digest)
00202 {
00203     guint count;
00204     guint8 *p;
00205 
00206     /* Compute number of bytes mod 64 */
00207     count = (ctx->bits[0] >> 3) & 0x3F;
00208 
00209     /* Set the first char of padding to 0x80.  This is safe since there is
00210        always at least one byte free */
00211     p = ctx->in + count;
00212     *p++ = 0x80;
00213 
00214     /* Bytes of padding needed to make 64 bytes */
00215     count = 64 - 1 - count;
00216 
00217     /* Pad out to 56 mod 64 */
00218     if (count < 8) {
00219         /* Two lots of padding:  Pad the first block to 64 bytes */
00220         memset(p, 0, count);
00221         aud_md5_bytereverse(ctx->in, 16);
00222         aud_md5_transform(ctx->buf, (guint32 *) ctx->in);
00223 
00224         /* Now fill the next block with 56 bytes */
00225         memset(ctx->in, 0, 56);
00226     } else {
00227         /* Pad block to 56 bytes */
00228         memset(p, 0, count - 8);
00229     }
00230     aud_md5_bytereverse(ctx->in, 14);
00231 
00232     /* Append length in bits and transform */
00233     ((guint32 *) ctx->in)[14] = ctx->bits[0];
00234     ((guint32 *) ctx->in)[15] = ctx->bits[1];
00235 
00236     aud_md5_transform(ctx->buf, (guint32 *) ctx->in);
00237     aud_md5_bytereverse((guint8 *) ctx->buf, 4);
00238     memcpy(digest, ctx->buf, 16);
00239     memset(ctx, 0, sizeof(ctx));    /* In case it's sensitive */
00240 }