freebsd-dev/lib/libmd/md4c.c
Xin LI 66bdf50fac libmd: Always erase context in _Final method, and when doing
it, consistently use explicit_bzero().

Update manual pages to match the behavior.

Reviewed by:	pfg, allanjude, jmg
MFC after:	1 month
Differential Revision:	https://reviews.freebsd.org/D16316
2018-07-20 07:01:28 +00:00

311 lines
8.9 KiB
C

/* MD4C.C - RSA Data Security, Inc., MD4 message-digest algorithm
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
/*-
SPDX-License-Identifier: RSA-MD
Copyright (C) 1990-2, RSA Data Security, Inc. All rights reserved.
License to copy and use this software is granted provided that it
is identified as the "RSA Data Security, Inc. MD4 Message-Digest
Algorithm" in all material mentioning or referencing this software
or this function.
License is also granted to make and use derivative works provided
that such works are identified as "derived from the RSA Data
Security, Inc. MD4 Message-Digest Algorithm" in all material
mentioning or referencing the derived work.
RSA Data Security, Inc. makes no representations concerning either
the merchantability of this software or the suitability of this
software for any particular purpose. It is provided "as is"
without express or implied warranty of any kind.
These notices must be retained in any copies of any part of this
documentation and/or software.
*/
#include <sys/types.h>
#include <string.h>
#include "md4.h"
typedef unsigned char *POINTER;
typedef const unsigned char *CONST_POINTER;
typedef u_int16_t UINT2;
typedef u_int32_t UINT4;
#define PROTO_LIST(list) list
/* Constants for MD4Transform routine.
*/
#define S11 3
#define S12 7
#define S13 11
#define S14 19
#define S21 3
#define S22 5
#define S23 9
#define S24 13
#define S31 3
#define S32 9
#define S33 11
#define S34 15
static void MD4Transform PROTO_LIST ((UINT4 [4], const unsigned char [64]));
static void Encode PROTO_LIST
((unsigned char *, UINT4 *, unsigned int));
static void Decode PROTO_LIST
((UINT4 *, const unsigned char *, unsigned int));
static unsigned char PADDING[64] = {
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
};
/* F, G and H are basic MD4 functions.
*/
#define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
#define G(x, y, z) (((x) & (y)) | ((x) & (z)) | ((y) & (z)))
#define H(x, y, z) ((x) ^ (y) ^ (z))
/* ROTATE_LEFT rotates x left n bits.
*/
#define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))
/* FF, GG and HH are transformations for rounds 1, 2 and 3 */
/* Rotation is separate from addition to prevent recomputation */
#define FF(a, b, c, d, x, s) { \
(a) += F ((b), (c), (d)) + (x); \
(a) = ROTATE_LEFT ((a), (s)); \
}
#define GG(a, b, c, d, x, s) { \
(a) += G ((b), (c), (d)) + (x) + (UINT4)0x5a827999; \
(a) = ROTATE_LEFT ((a), (s)); \
}
#define HH(a, b, c, d, x, s) { \
(a) += H ((b), (c), (d)) + (x) + (UINT4)0x6ed9eba1; \
(a) = ROTATE_LEFT ((a), (s)); \
}
/* MD4 initialization. Begins an MD4 operation, writing a new context.
*/
void MD4Init (context)
MD4_CTX *context; /* context */
{
context->count[0] = context->count[1] = 0;
/* Load magic initialization constants.
*/
context->state[0] = 0x67452301;
context->state[1] = 0xefcdab89;
context->state[2] = 0x98badcfe;
context->state[3] = 0x10325476;
}
/* MD4 block update operation. Continues an MD4 message-digest
operation, processing another message block, and updating the
context.
*/
void MD4Update (context, in, inputLen)
MD4_CTX *context; /* context */
const void *in; /* input block */
unsigned int inputLen; /* length of input block */
{
unsigned int i, idx, partLen;
const unsigned char *input = in;
/* Compute number of bytes mod 64 */
idx = (unsigned int)((context->count[0] >> 3) & 0x3F);
/* Update number of bits */
if ((context->count[0] += ((UINT4)inputLen << 3))
< ((UINT4)inputLen << 3))
context->count[1]++;
context->count[1] += ((UINT4)inputLen >> 29);
partLen = 64 - idx;
/* Transform as many times as possible.
*/
if (inputLen >= partLen) {
memcpy
((POINTER)&context->buffer[idx], (CONST_POINTER)input, partLen);
MD4Transform (context->state, context->buffer);
for (i = partLen; i + 63 < inputLen; i += 64)
MD4Transform (context->state, &input[i]);
idx = 0;
}
else
i = 0;
/* Buffer remaining input */
memcpy
((POINTER)&context->buffer[idx], (CONST_POINTER)&input[i],
inputLen-i);
}
/* MD4 padding. */
void MD4Pad (context)
MD4_CTX *context; /* context */
{
unsigned char bits[8];
unsigned int idx, padLen;
/* Save number of bits */
Encode (bits, context->count, 8);
/* Pad out to 56 mod 64.
*/
idx = (unsigned int)((context->count[0] >> 3) & 0x3f);
padLen = (idx < 56) ? (56 - idx) : (120 - idx);
MD4Update (context, PADDING, padLen);
/* Append length (before padding) */
MD4Update (context, bits, 8);
}
/* MD4 finalization. Ends an MD4 message-digest operation, writing the
the message digest and zeroizing the context.
*/
void MD4Final (digest, context)
unsigned char digest[16]; /* message digest */
MD4_CTX *context; /* context */
{
/* Do padding */
MD4Pad (context);
/* Store state in digest */
Encode (digest, context->state, 16);
/* Zeroize sensitive information.
*/
explicit_bzero(context, sizeof(*context));
}
/* MD4 basic transformation. Transforms state based on block.
*/
static void MD4Transform (state, block)
UINT4 state[4];
const unsigned char block[64];
{
UINT4 a = state[0], b = state[1], c = state[2], d = state[3], x[16];
Decode (x, block, 64);
/* Round 1 */
FF (a, b, c, d, x[ 0], S11); /* 1 */
FF (d, a, b, c, x[ 1], S12); /* 2 */
FF (c, d, a, b, x[ 2], S13); /* 3 */
FF (b, c, d, a, x[ 3], S14); /* 4 */
FF (a, b, c, d, x[ 4], S11); /* 5 */
FF (d, a, b, c, x[ 5], S12); /* 6 */
FF (c, d, a, b, x[ 6], S13); /* 7 */
FF (b, c, d, a, x[ 7], S14); /* 8 */
FF (a, b, c, d, x[ 8], S11); /* 9 */
FF (d, a, b, c, x[ 9], S12); /* 10 */
FF (c, d, a, b, x[10], S13); /* 11 */
FF (b, c, d, a, x[11], S14); /* 12 */
FF (a, b, c, d, x[12], S11); /* 13 */
FF (d, a, b, c, x[13], S12); /* 14 */
FF (c, d, a, b, x[14], S13); /* 15 */
FF (b, c, d, a, x[15], S14); /* 16 */
/* Round 2 */
GG (a, b, c, d, x[ 0], S21); /* 17 */
GG (d, a, b, c, x[ 4], S22); /* 18 */
GG (c, d, a, b, x[ 8], S23); /* 19 */
GG (b, c, d, a, x[12], S24); /* 20 */
GG (a, b, c, d, x[ 1], S21); /* 21 */
GG (d, a, b, c, x[ 5], S22); /* 22 */
GG (c, d, a, b, x[ 9], S23); /* 23 */
GG (b, c, d, a, x[13], S24); /* 24 */
GG (a, b, c, d, x[ 2], S21); /* 25 */
GG (d, a, b, c, x[ 6], S22); /* 26 */
GG (c, d, a, b, x[10], S23); /* 27 */
GG (b, c, d, a, x[14], S24); /* 28 */
GG (a, b, c, d, x[ 3], S21); /* 29 */
GG (d, a, b, c, x[ 7], S22); /* 30 */
GG (c, d, a, b, x[11], S23); /* 31 */
GG (b, c, d, a, x[15], S24); /* 32 */
/* Round 3 */
HH (a, b, c, d, x[ 0], S31); /* 33 */
HH (d, a, b, c, x[ 8], S32); /* 34 */
HH (c, d, a, b, x[ 4], S33); /* 35 */
HH (b, c, d, a, x[12], S34); /* 36 */
HH (a, b, c, d, x[ 2], S31); /* 37 */
HH (d, a, b, c, x[10], S32); /* 38 */
HH (c, d, a, b, x[ 6], S33); /* 39 */
HH (b, c, d, a, x[14], S34); /* 40 */
HH (a, b, c, d, x[ 1], S31); /* 41 */
HH (d, a, b, c, x[ 9], S32); /* 42 */
HH (c, d, a, b, x[ 5], S33); /* 43 */
HH (b, c, d, a, x[13], S34); /* 44 */
HH (a, b, c, d, x[ 3], S31); /* 45 */
HH (d, a, b, c, x[11], S32); /* 46 */
HH (c, d, a, b, x[ 7], S33); /* 47 */
HH (b, c, d, a, x[15], S34); /* 48 */
state[0] += a;
state[1] += b;
state[2] += c;
state[3] += d;
/* Zeroize sensitive information.
*/
memset ((POINTER)x, 0, sizeof (x));
}
/* Encodes input (UINT4) into output (unsigned char). Assumes len is
a multiple of 4.
*/
static void Encode (output, input, len)
unsigned char *output;
UINT4 *input;
unsigned int len;
{
unsigned int i, j;
for (i = 0, j = 0; j < len; i++, j += 4) {
output[j] = (unsigned char)(input[i] & 0xff);
output[j+1] = (unsigned char)((input[i] >> 8) & 0xff);
output[j+2] = (unsigned char)((input[i] >> 16) & 0xff);
output[j+3] = (unsigned char)((input[i] >> 24) & 0xff);
}
}
/* Decodes input (unsigned char) into output (UINT4). Assumes len is
a multiple of 4.
*/
static void Decode (output, input, len)
UINT4 *output;
const unsigned char *input;
unsigned int len;
{
unsigned int i, j;
for (i = 0, j = 0; j < len; i++, j += 4)
output[i] = ((UINT4)input[j]) | (((UINT4)input[j+1]) << 8) |
(((UINT4)input[j+2]) << 16) | (((UINT4)input[j+3]) << 24);
}
#ifdef WEAK_REFS
/* When building libmd, provide weak references. Note: this is not
activated in the context of compiling these sources for internal
use in libcrypt.
*/
#undef MD4Init
__weak_reference(_libmd_MD4Init, MD4Init);
#undef MD4Update
__weak_reference(_libmd_MD4Update, MD4Update);
#undef MD4Pad
__weak_reference(_libmd_MD4Pad, MD4Pad);
#undef MD4Final
__weak_reference(_libmd_MD4Final, MD4Final);
#endif