mongoose/src/md5.c
2023-09-29 13:09:29 +01:00

203 lines
6.5 KiB
C

#include "arch.h"
#include "md5.h"
// 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.
#if defined(MG_ENABLE_MD5) && MG_ENABLE_MD5
static void mg_byte_reverse(unsigned char *buf, unsigned longs) {
if (MG_BIG_ENDIAN) {
do {
uint32_t t = (uint32_t) ((unsigned) buf[3] << 8 | buf[2]) << 16 |
((unsigned) buf[1] << 8 | buf[0]);
*(uint32_t *) buf = t;
buf += 4;
} while (--longs);
} else {
(void) buf, (void) longs; // Little endian. Do nothing
}
}
#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))
#define MD5STEP(f, w, x, y, z, data, s) \
(w += f(x, y, z) + data, w = w << s | w >> (32 - s), w += x)
/*
* Start MD5 accumulation. Set bit count to 0 and buffer to mysterious
* initialization constants.
*/
void mg_md5_init(mg_md5_ctx *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;
}
static void mg_md5_transform(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);
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;
}
void mg_md5_update(mg_md5_ctx *ctx, const unsigned char *buf, size_t len) {
uint32_t t;
t = ctx->bits[0];
if ((ctx->bits[0] = t + ((uint32_t) len << 3)) < t) ctx->bits[1]++;
ctx->bits[1] += (uint32_t) len >> 29;
t = (t >> 3) & 0x3f;
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);
mg_byte_reverse(ctx->in, 16);
mg_md5_transform(ctx->buf, (uint32_t *) ctx->in);
buf += t;
len -= t;
}
while (len >= 64) {
memcpy(ctx->in, buf, 64);
mg_byte_reverse(ctx->in, 16);
mg_md5_transform(ctx->buf, (uint32_t *) ctx->in);
buf += 64;
len -= 64;
}
memcpy(ctx->in, buf, len);
}
void mg_md5_final(mg_md5_ctx *ctx, unsigned char digest[16]) {
unsigned count;
unsigned char *p;
uint32_t *a;
count = (ctx->bits[0] >> 3) & 0x3F;
p = ctx->in + count;
*p++ = 0x80;
count = 64 - 1 - count;
if (count < 8) {
memset(p, 0, count);
mg_byte_reverse(ctx->in, 16);
mg_md5_transform(ctx->buf, (uint32_t *) ctx->in);
memset(ctx->in, 0, 56);
} else {
memset(p, 0, count - 8);
}
mg_byte_reverse(ctx->in, 14);
a = (uint32_t *) ctx->in;
a[14] = ctx->bits[0];
a[15] = ctx->bits[1];
mg_md5_transform(ctx->buf, (uint32_t *) ctx->in);
mg_byte_reverse((unsigned char *) ctx->buf, 4);
memcpy(digest, ctx->buf, 16);
memset((char *) ctx, 0, sizeof(*ctx));
}
#endif