tomcrypt/md2.c
2010-06-16 12:38:16 +02:00

222 lines
6.0 KiB
C

/* LibTomCrypt, modular cryptographic library -- Tom St Denis
*
* LibTomCrypt is a library that provides various cryptographic
* algorithms in a highly modular and flexible manner.
*
* The library is free for all purposes without any express
* guarantee it works.
*
* Tom St Denis, tomstdenis@iahu.ca, http://libtomcrypt.org
*/
/* MD2 (RFC 1319) hash function implementation by Tom St Denis */
#include "mycrypt.h"
#ifdef MD2
const struct _hash_descriptor md2_desc =
{
"md2",
7,
16,
16,
/* DER encoding */
{ 0x30, 0x20, 0x30, 0x0C, 0x06, 0x08, 0x2A, 0x86,
0x48, 0x86, 0xF7, 0x0D, 0x02, 0x02, 0x05, 0x00,
0x04, 0x10 },
18,
&md2_init,
&md2_process,
&md2_done,
&md2_test
};
static const unsigned char PI_SUBST[256] = {
41, 46, 67, 201, 162, 216, 124, 1, 61, 54, 84, 161, 236, 240, 6,
19, 98, 167, 5, 243, 192, 199, 115, 140, 152, 147, 43, 217, 188,
76, 130, 202, 30, 155, 87, 60, 253, 212, 224, 22, 103, 66, 111, 24,
138, 23, 229, 18, 190, 78, 196, 214, 218, 158, 222, 73, 160, 251,
245, 142, 187, 47, 238, 122, 169, 104, 121, 145, 21, 178, 7, 63,
148, 194, 16, 137, 11, 34, 95, 33, 128, 127, 93, 154, 90, 144, 50,
39, 53, 62, 204, 231, 191, 247, 151, 3, 255, 25, 48, 179, 72, 165,
181, 209, 215, 94, 146, 42, 172, 86, 170, 198, 79, 184, 56, 210,
150, 164, 125, 182, 118, 252, 107, 226, 156, 116, 4, 241, 69, 157,
112, 89, 100, 113, 135, 32, 134, 91, 207, 101, 230, 45, 168, 2, 27,
96, 37, 173, 174, 176, 185, 246, 28, 70, 97, 105, 52, 64, 126, 15,
85, 71, 163, 35, 221, 81, 175, 58, 195, 92, 249, 206, 186, 197,
234, 38, 44, 83, 13, 110, 133, 40, 132, 9, 211, 223, 205, 244, 65,
129, 77, 82, 106, 220, 55, 200, 108, 193, 171, 250, 36, 225, 123,
8, 12, 189, 177, 74, 120, 136, 149, 139, 227, 99, 232, 109, 233,
203, 213, 254, 59, 0, 29, 57, 242, 239, 183, 14, 102, 88, 208, 228,
166, 119, 114, 248, 235, 117, 75, 10, 49, 68, 80, 180, 143, 237,
31, 26, 219, 153, 141, 51, 159, 17, 131, 20
};
/* adds 16 bytes to the checksum */
static void md2_update_chksum(hash_state *md)
{
int j;
unsigned char L;
L = md->md2.chksum[15];
for (j = 0; j < 16; j++) {
/* caution, the RFC says its "C[j] = S[M[i*16+j] xor L]" but the reference source code [and test vectors] say
otherwise.
*/
L = (md->md2.chksum[j] ^= PI_SUBST[(int)(md->md2.buf[j] ^ L)] & 255);
}
}
static void md2_compress(hash_state *md)
{
int j, k;
unsigned char t;
/* copy block */
for (j = 0; j < 16; j++) {
md->md2.X[16+j] = md->md2.buf[j];
md->md2.X[32+j] = md->md2.X[j] ^ md->md2.X[16+j];
}
t = (unsigned char)0;
/* do 18 rounds */
for (j = 0; j < 18; j++) {
for (k = 0; k < 48; k++) {
t = (md->md2.X[k] ^= PI_SUBST[(int)(t & 255)]);
}
t = (t + (unsigned char)j) & 255;
}
}
void md2_init(hash_state *md)
{
_ARGCHK(md != NULL);
/* MD2 uses a zero'ed state... */
zeromem(md->md2.X, sizeof(md->md2.X));
zeromem(md->md2.chksum, sizeof(md->md2.chksum));
zeromem(md->md2.buf, sizeof(md->md2.buf));
md->md2.curlen = 0;
}
int md2_process(hash_state *md, const unsigned char *buf, unsigned long len)
{
unsigned long n;
_ARGCHK(md != NULL);
_ARGCHK(buf != NULL);
if (md-> md2 .curlen > sizeof(md-> md2 .buf)) {
return CRYPT_INVALID_ARG;
}
while (len > 0) {
n = MIN(len, (16 - md->md2.curlen));
XMEMCPY(md->md2.buf + md->md2.curlen, buf, (size_t)n);
md->md2.curlen += n;
buf += n;
len -= n;
/* is 16 bytes full? */
if (md->md2.curlen == 16) {
md2_compress(md);
md2_update_chksum(md);
md->md2.curlen = 0;
}
}
return CRYPT_OK;
}
int md2_done(hash_state * md, unsigned char *hash)
{
unsigned long i, k;
_ARGCHK(md != NULL);
_ARGCHK(hash != NULL);
if (md->md2.curlen >= sizeof(md->md2.buf)) {
return CRYPT_INVALID_ARG;
}
/* pad the message */
k = 16 - md->md2.curlen;
for (i = md->md2.curlen; i < 16; i++) {
md->md2.buf[i] = (unsigned char)k;
}
/* hash and update */
md2_compress(md);
md2_update_chksum(md);
/* hash checksum */
XMEMCPY(md->md2.buf, md->md2.chksum, 16);
md2_compress(md);
/* output is lower 16 bytes of X */
XMEMCPY(hash, md->md2.X, 16);
#ifdef CLEAN_STACK
zeromem(md, sizeof(hash_state));
#endif
return CRYPT_OK;
}
int md2_test(void)
{
#ifndef LTC_TEST
return CRYPT_NOP;
#else
static const struct {
char *msg;
unsigned char md[16];
} tests[] = {
{ "",
{0x83,0x50,0xe5,0xa3,0xe2,0x4c,0x15,0x3d,
0xf2,0x27,0x5c,0x9f,0x80,0x69,0x27,0x73
}
},
{ "a",
{0x32,0xec,0x01,0xec,0x4a,0x6d,0xac,0x72,
0xc0,0xab,0x96,0xfb,0x34,0xc0,0xb5,0xd1
}
},
{ "message digest",
{0xab,0x4f,0x49,0x6b,0xfb,0x2a,0x53,0x0b,
0x21,0x9f,0xf3,0x30,0x31,0xfe,0x06,0xb0
}
},
{ "abcdefghijklmnopqrstuvwxyz",
{0x4e,0x8d,0xdf,0xf3,0x65,0x02,0x92,0xab,
0x5a,0x41,0x08,0xc3,0xaa,0x47,0x94,0x0b
}
},
{ "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789",
{0xda,0x33,0xde,0xf2,0xa4,0x2d,0xf1,0x39,
0x75,0x35,0x28,0x46,0xc3,0x03,0x38,0xcd
}
},
{ "12345678901234567890123456789012345678901234567890123456789012345678901234567890",
{0xd5,0x97,0x6f,0x79,0xd8,0x3d,0x3a,0x0d,
0xc9,0x80,0x6c,0x3c,0x66,0xf3,0xef,0xd8
}
}
};
int i;
hash_state md;
unsigned char buf[16];
for (i = 0; i < (int)(sizeof(tests) / sizeof(tests[0])); i++) {
md2_init(&md);
md2_process(&md, (unsigned char*)tests[i].msg, (unsigned long)strlen(tests[i].msg));
md2_done(&md, buf);
if (memcmp(buf, tests[i].md, 16) != 0) {
return CRYPT_FAIL_TESTVECTOR;
}
}
return CRYPT_OK;
#endif
}
#endif