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md5.c

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00001 /* MD5 checksum routines used for authentication.  Not covered by GPL, but
00002    in the public domain as per the copyright below */
00003 
00004 # if __BYTE_ORDER == __BIG_ENDIAN || BYTE_ORDER == BIG_ENDIAN
00005 #  define HIGHFIRST 1
00006 # endif
00007 
00008 /*
00009  * This code implements the MD5 message-digest algorithm.
00010  * The algorithm is due to Ron Rivest.  This code was
00011  * written by Colin Plumb in 1993, no copyright is claimed.
00012  * This code is in the public domain; do with it what you wish.
00013  *
00014  * Equivalent code is available from RSA Data Security, Inc.
00015  * This code has been tested against that, and is equivalent,
00016  * except that you don't need to include two pages of legalese
00017  * with every copy.
00018  *
00019  * To compute the message digest of a chunk of bytes, declare an
00020  * MD5Context structure, pass it to MD5Init, call MD5Update as
00021  * needed on buffers full of bytes, and then call MD5Final, which
00022  * will fill a supplied 16-byte array with the digest.
00023  */
00024 #include <string.h>     /* for memcpy() */
00025 #include <asterisk/md5.h>
00026 
00027 #ifndef HIGHFIRST
00028 #define byteReverse(buf, len) /* Nothing */
00029 #else
00030 void byteReverse(unsigned char *buf, unsigned longs);
00031 
00032 #ifndef ASM_MD5
00033 /*
00034  * Note: this code is harmless on little-endian machines.
00035  */
00036 void byteReverse(unsigned char *buf, unsigned longs)
00037 {
00038     uint32 t;
00039     do {
00040    t = (uint32) ((unsigned) buf[3] << 8 | buf[2]) << 16 |
00041        ((unsigned) buf[1] << 8 | buf[0]);
00042    *(uint32 *) buf = t;
00043    buf += 4;
00044     } while (--longs);
00045 }
00046 #endif
00047 #endif
00048 
00049 /*
00050  * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious
00051  * initialization constants.
00052  */
00053 void MD5Init(struct MD5Context *ctx)
00054 {
00055     ctx->buf[0] = 0x67452301;
00056     ctx->buf[1] = 0xefcdab89;
00057     ctx->buf[2] = 0x98badcfe;
00058     ctx->buf[3] = 0x10325476;
00059 
00060     ctx->bits[0] = 0;
00061     ctx->bits[1] = 0;
00062 }
00063 
00064 /*
00065  * Update context to reflect the concatenation of another buffer full
00066  * of bytes.
00067  */
00068 void MD5Update(struct MD5Context *ctx, unsigned char const *buf, unsigned len)
00069 {
00070     uint32 t;
00071 
00072     /* Update bitcount */
00073 
00074     t = ctx->bits[0];
00075     if ((ctx->bits[0] = t + ((uint32) len << 3)) < t)
00076    ctx->bits[1]++;      /* Carry from low to high */
00077     ctx->bits[1] += len >> 29;
00078 
00079     t = (t >> 3) & 0x3f;   /* Bytes already in shsInfo->data */
00080 
00081     /* Handle any leading odd-sized chunks */
00082 
00083     if (t) {
00084    unsigned char *p = (unsigned char *) ctx->in + t;
00085 
00086    t = 64 - t;
00087    if (len < t) {
00088        memcpy(p, buf, len);
00089        return;
00090    }
00091    memcpy(p, buf, t);
00092    byteReverse(ctx->in, 16);
00093    MD5Transform(ctx->buf, (uint32 *) ctx->in);
00094    buf += t;
00095    len -= t;
00096     }
00097     /* Process data in 64-byte chunks */
00098 
00099     while (len >= 64) {
00100    memcpy(ctx->in, buf, 64);
00101    byteReverse(ctx->in, 16);
00102    MD5Transform(ctx->buf, (uint32 *) ctx->in);
00103    buf += 64;
00104    len -= 64;
00105     }
00106 
00107     /* Handle any remaining bytes of data. */
00108 
00109     memcpy(ctx->in, buf, len);
00110 }
00111 
00112 /*
00113  * Final wrapup - pad to 64-byte boundary with the bit pattern 
00114  * 1 0* (64-bit count of bits processed, MSB-first)
00115  */
00116 void MD5Final(unsigned char digest[16], struct MD5Context *ctx)
00117 {
00118     unsigned count;
00119     unsigned char *p;
00120 
00121     /* Compute number of bytes mod 64 */
00122     count = (ctx->bits[0] >> 3) & 0x3F;
00123 
00124     /* Set the first char of padding to 0x80.  This is safe since there is
00125        always at least one byte free */
00126     p = ctx->in + count;
00127     *p++ = 0x80;
00128 
00129     /* Bytes of padding needed to make 64 bytes */
00130     count = 64 - 1 - count;
00131 
00132     /* Pad out to 56 mod 64 */
00133     if (count < 8) {
00134    /* Two lots of padding:  Pad the first block to 64 bytes */
00135    memset(p, 0, count);
00136    byteReverse(ctx->in, 16);
00137    MD5Transform(ctx->buf, (uint32 *) ctx->in);
00138 
00139    /* Now fill the next block with 56 bytes */
00140    memset(ctx->in, 0, 56);
00141     } else {
00142    /* Pad block to 56 bytes */
00143    memset(p, 0, count - 8);
00144     }
00145     byteReverse(ctx->in, 14);
00146 
00147     /* Append length in bits and transform */
00148     ((uint32 *) ctx->in)[14] = ctx->bits[0];
00149     ((uint32 *) ctx->in)[15] = ctx->bits[1];
00150 
00151     MD5Transform(ctx->buf, (uint32 *) ctx->in);
00152     byteReverse((unsigned char *) ctx->buf, 4);
00153     memcpy(digest, ctx->buf, 16);
00154     memset(ctx, 0, sizeof(ctx)); /* In case it's sensitive */
00155 }
00156 
00157 #ifndef ASM_MD5
00158 
00159 /* The four core functions - F1 is optimized somewhat */
00160 
00161 /* #define F1(x, y, z) (x & y | ~x & z) */
00162 #define F1(x, y, z) (z ^ (x & (y ^ z)))
00163 #define F2(x, y, z) F1(z, x, y)
00164 #define F3(x, y, z) (x ^ y ^ z)
00165 #define F4(x, y, z) (y ^ (x | ~z))
00166 
00167 /* This is the central step in the MD5 algorithm. */
00168 #define MD5STEP(f, w, x, y, z, data, s) \
00169    ( w += f(x, y, z) + data,  w = w<<s | w>>(32-s),  w += x )
00170 
00171 /*
00172  * The core of the MD5 algorithm, this alters an existing MD5 hash to
00173  * reflect the addition of 16 longwords of new data.  MD5Update blocks
00174  * the data and converts bytes into longwords for this routine.
00175  */
00176 void MD5Transform(uint32 buf[4], uint32 const in[16])
00177 {
00178     register uint32 a, b, c, d;
00179 
00180     a = buf[0];
00181     b = buf[1];
00182     c = buf[2];
00183     d = buf[3];
00184 
00185     MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
00186     MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
00187     MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
00188     MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
00189     MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
00190     MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
00191     MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
00192     MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
00193     MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
00194     MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
00195     MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
00196     MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
00197     MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
00198     MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
00199     MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
00200     MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
00201 
00202     MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
00203     MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
00204     MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
00205     MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
00206     MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
00207     MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
00208     MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
00209     MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
00210     MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
00211     MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
00212     MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
00213     MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
00214     MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
00215     MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
00216     MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
00217     MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
00218 
00219     MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
00220     MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
00221     MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
00222     MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
00223     MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
00224     MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
00225     MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
00226     MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
00227     MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
00228     MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
00229     MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
00230     MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
00231     MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
00232     MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
00233     MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
00234     MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
00235 
00236     MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
00237     MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
00238     MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
00239     MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
00240     MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
00241     MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
00242     MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
00243     MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
00244     MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
00245     MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
00246     MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
00247     MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
00248     MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
00249     MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
00250     MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
00251     MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
00252 
00253     buf[0] += a;
00254     buf[1] += b;
00255     buf[2] += c;
00256     buf[3] += d;
00257 }
00258 
00259 #endif

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