diff options
Diffstat (limited to 'lib/md5.c')
-rw-r--r-- | lib/md5.c | 252 |
1 files changed, 252 insertions, 0 deletions
diff --git a/lib/md5.c b/lib/md5.c new file mode 100644 index 00000000..9fec594c --- /dev/null +++ b/lib/md5.c @@ -0,0 +1,252 @@ +/* + * 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. + */ + +/* + * Adapted for BIRD by Martin Mares <mj@atrey.karlin.mff.cuni.cz> + */ + +#include <string.h> /* for memcpy() */ +#include "nest/bird.h" +#include "md5.h" + +#ifdef CPU_LITTLE_ENDIAN +#define byteReverse(buf, len) /* Nothing */ +#else +void byteReverse(unsigned char *buf, unsigned longs); + +/* + * Note: this code is harmless on little-endian machines. + */ +void byteReverse(unsigned char *buf, unsigned longs) +{ + u32 t; + do { + t = (u32) ((unsigned) buf[3] << 8 | buf[2]) << 16 | + ((unsigned) buf[1] << 8 | buf[0]); + *(u32 *) buf = t; + buf += 4; + } while (--longs); +} +#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) +{ + u32 t; + + /* Update bitcount */ + + t = ctx->bits[0]; + if ((ctx->bits[0] = t + ((u32) 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, (u32 *) 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, (u32 *) 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; + + /* 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, (u32 *) 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 */ + ((u32 *) ctx->in)[14] = ctx->bits[0]; + ((u32 *) ctx->in)[15] = ctx->bits[1]; + + MD5Transform(ctx->buf, (u32 *) ctx->in); + byteReverse((unsigned char *) ctx->buf, 4); + memcpy(digest, ctx->buf, 16); + memset((char *) 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<<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(u32 buf[4], u32 const in[16]) +{ + register u32 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; +} |