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/* $OpenBSD: md4.c,v 1.3 2004/04/29 18:45:39 millert Exp $ */
/*
* This code implements the MD4 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.
* Todd C. Miller modified the MD5 code to do MD4 based on RFC 1186.
*
* 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
* MD4Context structure, pass it to MD4Init, call MD4Update as
* needed on buffers full of bytes, and then call MD4Final, which
* will fill a supplied 16-byte array with the digest.
*/
#if defined(LIBC_SCCS) && !defined(lint)
static const char rcsid[] = "$OpenBSD: md4.c,v 1.3 2004/04/29 18:45:39 millert Exp $";
#endif /* LIBC_SCCS and not lint */
#include <sys/types.h>
#include <string.h>
#include <md4.h>
#define PUT_64BIT_LE(cp, value) do { \
(cp)[7] = (value) >> 56; \
(cp)[6] = (value) >> 48; \
(cp)[5] = (value) >> 40; \
(cp)[4] = (value) >> 32; \
(cp)[3] = (value) >> 24; \
(cp)[2] = (value) >> 16; \
(cp)[1] = (value) >> 8; \
(cp)[0] = (value); } while (0)
#define PUT_32BIT_LE(cp, value) do { \
(cp)[3] = (value) >> 24; \
(cp)[2] = (value) >> 16; \
(cp)[1] = (value) >> 8; \
(cp)[0] = (value); } while (0)
static u_char PADDING[MD4_BLOCK_LENGTH] = {
0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};
/*
* Start MD4 accumulation.
* Set bit count to 0 and buffer to mysterious initialization constants.
*/
void
MD4Init(MD4_CTX *ctx)
{
ctx->count = 0;
ctx->state[0] = 0x67452301;
ctx->state[1] = 0xefcdab89;
ctx->state[2] = 0x98badcfe;
ctx->state[3] = 0x10325476;
}
/*
* Update context to reflect the concatenation of another buffer full
* of bytes.
*/
void
MD4Update(MD4_CTX *ctx, const unsigned char *input, size_t len)
{
u_int32_t have, need;
/* Check how many bytes we already have and how many more we need. */
have = (u_int32_t)((ctx->count >> 3) & (MD4_BLOCK_LENGTH - 1));
need = MD4_BLOCK_LENGTH - have;
/* Update bitcount */
ctx->count += (u_int64_t)len << 3;
if (len >= need) {
if (have != 0) {
memcpy(ctx->buffer + have, input, need);
MD4Transform(ctx->state, ctx->buffer);
input += need;
len -= need;
have = 0;
}
/* Process data in MD4_BLOCK_LENGTH-byte chunks. */
while (len >= MD4_BLOCK_LENGTH) {
MD4Transform(ctx->state, input);
input += MD4_BLOCK_LENGTH;
len -= MD4_BLOCK_LENGTH;
}
}
/* Handle any remaining bytes of data. */
if (len != 0)
memcpy(ctx->buffer + have, input, len);
}
/*
* Final wrapup - pad to 64-byte boundary with the bit pattern
* 1 0* (64-bit count of bits processed, MSB-first)
*/
void
MD4Final(unsigned char digest[MD4_DIGEST_LENGTH], MD4_CTX *ctx)
{
u_int8_t count[8];
u_int32_t padlen;
int i;
/* Convert count to 8 bytes in little endian order. */
PUT_64BIT_LE(count, ctx->count);
/* Pad out to 56 mod 64. */
padlen = MD4_BLOCK_LENGTH -
((ctx->count >> 3) & (MD4_BLOCK_LENGTH - 1));
if (padlen < 1 + 8)
padlen += MD4_BLOCK_LENGTH;
MD4Update(ctx, PADDING, padlen - 8); /* padlen - 8 <= 64 */
MD4Update(ctx, count, 8);
if (digest != NULL) {
for (i = 0; i < 4; i++)
PUT_32BIT_LE(digest + i * 4, ctx->state[i]);
}
memset(ctx, 0, sizeof(*ctx)); /* in case it's sensitive */
}
/* The three 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) ((x & y) | (x & z) | (y & z))
#define F3(x, y, z) (x ^ y ^ z)
/* This is the central step in the MD4 algorithm. */
#define MD4STEP(f, w, x, y, z, data, s) \
( w += f(x, y, z) + data, w = w<<s | w>>(32-s) )
/*
* The core of the MD4 algorithm, this alters an existing MD4 hash to
* reflect the addition of 16 longwords of new data. MD4Update blocks
* the data and converts bytes into longwords for this routine.
*/
void
MD4Transform(u_int32_t state[4], const u_int8_t block[MD4_BLOCK_LENGTH])
{
u_int32_t a, b, c, d, in[MD4_BLOCK_LENGTH / 4];
#if BYTE_ORDER == LITTLE_ENDIAN
memcpy(in, block, sizeof(in));
#else
for (a = 0; a < MD4_BLOCK_LENGTH / 4; a++) {
in[a] = (u_int32_t)(
(u_int32_t)(block[a * 4 + 0]) |
(u_int32_t)(block[a * 4 + 1]) << 8 |
(u_int32_t)(block[a * 4 + 2]) << 16 |
(u_int32_t)(block[a * 4 + 3]) << 24);
}
#endif
a = state[0];
b = state[1];
c = state[2];
d = state[3];
MD4STEP(F1, a, b, c, d, in[ 0], 3);
MD4STEP(F1, d, a, b, c, in[ 1], 7);
MD4STEP(F1, c, d, a, b, in[ 2], 11);
MD4STEP(F1, b, c, d, a, in[ 3], 19);
MD4STEP(F1, a, b, c, d, in[ 4], 3);
MD4STEP(F1, d, a, b, c, in[ 5], 7);
MD4STEP(F1, c, d, a, b, in[ 6], 11);
MD4STEP(F1, b, c, d, a, in[ 7], 19);
MD4STEP(F1, a, b, c, d, in[ 8], 3);
MD4STEP(F1, d, a, b, c, in[ 9], 7);
MD4STEP(F1, c, d, a, b, in[10], 11);
MD4STEP(F1, b, c, d, a, in[11], 19);
MD4STEP(F1, a, b, c, d, in[12], 3);
MD4STEP(F1, d, a, b, c, in[13], 7);
MD4STEP(F1, c, d, a, b, in[14], 11);
MD4STEP(F1, b, c, d, a, in[15], 19);
MD4STEP(F2, a, b, c, d, in[ 0] + 0x5a827999, 3);
MD4STEP(F2, d, a, b, c, in[ 4] + 0x5a827999, 5);
MD4STEP(F2, c, d, a, b, in[ 8] + 0x5a827999, 9);
MD4STEP(F2, b, c, d, a, in[12] + 0x5a827999, 13);
MD4STEP(F2, a, b, c, d, in[ 1] + 0x5a827999, 3);
MD4STEP(F2, d, a, b, c, in[ 5] + 0x5a827999, 5);
MD4STEP(F2, c, d, a, b, in[ 9] + 0x5a827999, 9);
MD4STEP(F2, b, c, d, a, in[13] + 0x5a827999, 13);
MD4STEP(F2, a, b, c, d, in[ 2] + 0x5a827999, 3);
MD4STEP(F2, d, a, b, c, in[ 6] + 0x5a827999, 5);
MD4STEP(F2, c, d, a, b, in[10] + 0x5a827999, 9);
MD4STEP(F2, b, c, d, a, in[14] + 0x5a827999, 13);
MD4STEP(F2, a, b, c, d, in[ 3] + 0x5a827999, 3);
MD4STEP(F2, d, a, b, c, in[ 7] + 0x5a827999, 5);
MD4STEP(F2, c, d, a, b, in[11] + 0x5a827999, 9);
MD4STEP(F2, b, c, d, a, in[15] + 0x5a827999, 13);
MD4STEP(F3, a, b, c, d, in[ 0] + 0x6ed9eba1, 3);
MD4STEP(F3, d, a, b, c, in[ 8] + 0x6ed9eba1, 9);
MD4STEP(F3, c, d, a, b, in[ 4] + 0x6ed9eba1, 11);
MD4STEP(F3, b, c, d, a, in[12] + 0x6ed9eba1, 15);
MD4STEP(F3, a, b, c, d, in[ 2] + 0x6ed9eba1, 3);
MD4STEP(F3, d, a, b, c, in[10] + 0x6ed9eba1, 9);
MD4STEP(F3, c, d, a, b, in[ 6] + 0x6ed9eba1, 11);
MD4STEP(F3, b, c, d, a, in[14] + 0x6ed9eba1, 15);
MD4STEP(F3, a, b, c, d, in[ 1] + 0x6ed9eba1, 3);
MD4STEP(F3, d, a, b, c, in[ 9] + 0x6ed9eba1, 9);
MD4STEP(F3, c, d, a, b, in[ 5] + 0x6ed9eba1, 11);
MD4STEP(F3, b, c, d, a, in[13] + 0x6ed9eba1, 15);
MD4STEP(F3, a, b, c, d, in[ 3] + 0x6ed9eba1, 3);
MD4STEP(F3, d, a, b, c, in[11] + 0x6ed9eba1, 9);
MD4STEP(F3, c, d, a, b, in[ 7] + 0x6ed9eba1, 11);
MD4STEP(F3, b, c, d, a, in[15] + 0x6ed9eba1, 15);
state[0] += a;
state[1] += b;
state[2] += c;
state[3] += d;
}
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