md5.c

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/*!\file
\brief MD5 checksum routines used for authentication. Not covered by GPL, but
 in the public domain as per the copyright below */

/*
 * 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.
 */

#include "asterisk.h"

#include "asterisk/endian.h"
#include "asterisk/md5.h"

# if __BYTE_ORDER == __BIG_ENDIAN
# define HIGHFIRST 1
# endif
#ifndef HIGHFIRST
#define byteReverse(buf, len) /* Nothing */
#else
void byteReverse(unsigned char *buf, unsigned longs);

#ifndef ASM_MD5
/*
 * Note: this code is harmless on little-endian machines.
 */
void byteReverse(unsigned char *buf, unsigned longs)
{
 uint32_t t;
 do {
 t = (uint32_t) ((unsigned) buf[3] << 8 | buf[2]) << 16 |
 ((unsigned) buf[1] << 8 | buf[0]);
 *(uint32_t *) buf = t;
 buf += 4;
 } while (--longs);
}
#endif
#endif

/*
 * Start MD5 accumulation. Set bit count to 0 and buffer to mysterious
 * initialization constants.
 */
void MD5Init(struct MD5Context *ctx)
{
 ctx->buf[0] = 0x67452301;
 ctx->buf[1] = 0xefcdab89;
 ctx->buf[2] = 0x98badcfe;
 ctx->buf[3] = 0x10325476;

 ctx->bits[0] = 0;
 ctx->bits[1] = 0;
}

/*
 * Update context to reflect the concatenation of another buffer full
 * of bytes.
 */
void MD5Update(struct MD5Context *ctx, unsigned char const *buf, unsigned len)
{
 uint32_t t;

 /* Update bitcount */

 t = ctx->bits[0];
 if ((ctx->bits[0] = t + ((uint32_t) 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);
 byteReverse(ctx->in, 16);
 MD5Transform(ctx->buf, (uint32_t *) ctx->in);
 buf += t;
 len -= t;
 }
 /* Process data in 64-byte chunks */

 while (len >= 64) {
 memcpy(ctx->in, buf, 64);
 byteReverse(ctx->in, 16);
 MD5Transform(ctx->buf, (uint32_t *) 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 MD5Final(unsigned char digest[16], struct MD5Context *ctx)
{
 unsigned count;
 unsigned char *p;
 uint32_t *in_buf;

 /* 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);
 byteReverse(ctx->in, 16);
 MD5Transform(ctx->buf, (uint32_t *) 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);
 }
 byteReverse(ctx->in, 14);

 /* Append length in bits and transform */
 in_buf = (uint32_t *) ctx->in;
 in_buf[14] = ctx->bits[0];
 in_buf[15] = ctx->bits[1];

 MD5Transform(ctx->buf, (uint32_t *) ctx->in);
 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 MD5Transform(uint32_t buf[4], uint32_t const in[16])
{
 register uint32_t 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