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mirror of https://gitlab.nic.cz/labs/bird.git synced 2024-11-15 07:38:43 +00:00
bird/lib/md5.c
2015-11-24 16:01:48 +01:00

323 lines
8.6 KiB
C

/*
* BIRD Library -- MD5 Hash Function and HMAC-MD5 Function
*
* (c) 2015 CZ.NIC z.s.p.o.
*
* The code was written by Colin Plumb in 1993, no copyright is claimed.
*
* Adapted for BIRD by Martin Mares <mj@ucw.cz>
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
#include "lib/md5.h"
#ifdef CPU_LITTLE_ENDIAN
#define byteReverse(buf, len) /* Nothing */
#else
void byteReverse(byte *buf, uint longs);
/*
* Note: this code is harmless on little-endian machines.
*/
void byteReverse(byte *buf, uint longs)
{
u32 t;
do {
t = (u32) ((uint) buf[3] << 8 | buf[2]) << 16 |
((uint) buf[1] << 8 | buf[0]);
*(u32 *) buf = t;
buf += 4;
} while (--longs);
}
#endif
static void md5_transform(u32 buf[4], u32 const in[16]);
/*
* Start MD5 accumulation. Set bit count to 0 and buffer to mysterious
* initialization constants.
*/
void
md5_init(struct md5_context *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
md5_update(struct md5_context *ctx, const byte *buf, uint 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)
{
byte *p = (byte *) ctx->in + t;
t = 64 - t;
if (len < t)
{
memcpy(p, buf, len);
return;
}
memcpy(p, buf, t);
byteReverse(ctx->in, 16);
md5_transform(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);
md5_transform(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)
*/
byte *
md5_final(struct md5_context *ctx)
{
uint count;
byte *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);
md5_transform(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];
md5_transform(ctx->buf, (u32 *) ctx->in);
byteReverse((byte *) ctx->buf, 4);
return (byte*) ctx->buf;
}
/* I am a hard paranoid */
void
md5_erase_ctx(struct md5_context *ctx)
{
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
md5_transform(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;
}
/*
* MD5-HMAC
*/
static void
md5_hash_buffer(byte *outbuf, const byte *buffer, size_t length)
{
struct md5_context hd_tmp;
md5_init(&hd_tmp);
md5_update(&hd_tmp, buffer, length);
memcpy(outbuf, md5_final(&hd_tmp), MD5_SIZE);
}
void
md5_hmac_init(struct md5_hmac_context *ctx, const byte *key, size_t keylen)
{
byte keybuf[MD5_BLOCK_SIZE], buf[MD5_BLOCK_SIZE];
/* Hash the key if necessary */
if (keylen <= MD5_BLOCK_SIZE)
{
memcpy(keybuf, key, keylen);
bzero(keybuf + keylen, MD5_BLOCK_SIZE - keylen);
}
else
{
md5_hash_buffer(keybuf, key, keylen);
bzero(keybuf + MD5_SIZE, MD5_BLOCK_SIZE - MD5_SIZE);
}
/* Initialize the inner digest */
md5_init(&ctx->ictx);
int i;
for (i = 0; i < MD5_BLOCK_SIZE; i++)
buf[i] = keybuf[i] ^ 0x36;
md5_update(&ctx->ictx, buf, MD5_BLOCK_SIZE);
/* Initialize the outer digest */
md5_init(&ctx->octx);
for (i = 0; i < MD5_BLOCK_SIZE; i++)
buf[i] = keybuf[i] ^ 0x5c;
md5_update(&ctx->octx, buf, MD5_BLOCK_SIZE);
}
void
md5_hmac_update(struct md5_hmac_context *ctx, const byte *buf, size_t buflen)
{
/* Just update the inner digest */
md5_update(&ctx->ictx, buf, buflen);
}
byte *
md5_hmac_final(struct md5_hmac_context *ctx)
{
/* Finish the inner digest */
byte *isha = md5_final(&ctx->ictx);
/* Finish the outer digest */
md5_update(&ctx->octx, isha, MD5_SIZE);
return md5_final(&ctx->octx);
}