/* * 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 "config.h" #include "fm_md5.h" #ifdef HAVE_STRING_H #include /* memmove */ #endif #include /* * Note: this code is harmless on little-endian machines. */ static 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); } /* * 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, const void *buf_, unsigned len) { const unsigned char *buf = (const unsigned char *)buf_; 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->u.in + t; t = 64 - t; if (len < t) { memmove(p, buf, len); return; } memmove(p, buf, t); byteReverse(ctx->u.in, 16); MD5Transform(ctx->buf, ctx->u.in32); buf += t; len -= t; } /* Process data in 64-byte chunks */ while (len >= 64) { memmove(ctx->u.in, buf, 64); byteReverse(ctx->u.in, 16); MD5Transform(ctx->buf, ctx->u.in32); buf += 64; len -= 64; } /* Handle any remaining bytes of data. */ memmove(ctx->u.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(void *digest, struct MD5Context *ctx) { unsigned int 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->u.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->u.in, 16); MD5Transform(ctx->buf, ctx->u.in32); /* Now fill the next block with 56 bytes */ memset(ctx->u.in, 0, 56); } else { /* Pad block to 56 bytes */ memset(p, 0, count - 8); } byteReverse(ctx->u.in, 14); /* Append length in bits and transform */ ctx->u.in32[14] = ctx->bits[0]; ctx->u.in32[15] = ctx->bits[1]; MD5Transform(ctx->buf, ctx->u.in32); byteReverse((unsigned char *) ctx->buf, 4); memmove(digest, ctx->buf, 16); memset(ctx, 0, sizeof(*ctx)); /* In case it's sensitive */ } /* 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<>(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]) { 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); MD5