libtomcrypt/pmac.c
2010-06-16 12:38:09 +02:00

438 lines
11 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
* gurantee it works.
*
* Tom St Denis, tomstdenis@iahu.ca, http://libtomcrypt.org
*/
/* PMAC implementation by Tom St Denis */
#include "mycrypt.h"
#ifdef PMAC
static const struct {
int len;
unsigned char poly_div[MAXBLOCKSIZE],
poly_mul[MAXBLOCKSIZE];
} polys[] = {
{
8,
{ 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0D },
{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x1B }
}, {
16,
{ 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x43 },
{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x87 }
}
};
int pmac_init(pmac_state *pmac, int cipher, const unsigned char *key, unsigned long keylen)
{
int poly, x, y, m, err;
unsigned char L[MAXBLOCKSIZE];
_ARGCHK(pmac != NULL);
_ARGCHK(key != NULL);
/* valid cipher? */
if ((err = cipher_is_valid(cipher)) != CRYPT_OK) {
return err;
}
/* determine which polys to use */
pmac->block_len = cipher_descriptor[cipher].block_length;
for (poly = 0; poly < (int)(sizeof(polys)/sizeof(polys[0])); poly++) {
if (polys[poly].len == pmac->block_len) {
break;
}
}
if (polys[poly].len != pmac->block_len) {
return CRYPT_INVALID_ARG;
}
/* schedule the key */
if ((err = cipher_descriptor[cipher].setup(key, keylen, 0, &pmac->key)) != CRYPT_OK) {
return err;
}
/* find L = E[0] */
zeromem(L, pmac->block_len);
cipher_descriptor[cipher].ecb_encrypt(L, L, &pmac->key);
/* find Ls[i] = L << i for i == 0..31 */
memcpy(pmac->Ls[0], L, pmac->block_len);
for (x = 1; x < 32; x++) {
m = pmac->Ls[x-1][0] >> 7;
for (y = 0; y < pmac->block_len-1; y++) {
pmac->Ls[x][y] = ((pmac->Ls[x-1][y] << 1) | (pmac->Ls[x-1][y+1] >> 7)) & 255;
}
pmac->Ls[x][pmac->block_len-1] = (pmac->Ls[x-1][pmac->block_len-1] << 1) & 255;
if (m == 1) {
for (y = 0; y < pmac->block_len; y++) {
pmac->Ls[x][y] ^= polys[poly].poly_mul[y];
}
}
}
/* find Lr = L / x */
m = L[pmac->block_len-1] & 1;
/* shift right */
for (x = pmac->block_len - 1; x > 0; x--) {
pmac->Lr[x] = ((L[x] >> 1) | (L[x-1] << 7)) & 255;
}
pmac->Lr[0] = L[0] >> 1;
if (m == 1) {
for (x = 0; x < pmac->block_len; x++) {
pmac->Lr[x] ^= polys[poly].poly_div[x];
}
}
/* zero buffer, counters, etc... */
pmac->block_index = 1;
pmac->cipher_idx = cipher;
pmac->buflen = 0;
zeromem(pmac->block, sizeof(pmac->block));
zeromem(pmac->Li, sizeof(pmac->Li));
zeromem(pmac->checksum, sizeof(pmac->checksum));
#ifdef CLEAN_STACK
zeromem(L, sizeof(L));
#endif
return CRYPT_OK;
}
static int ntz(unsigned long x)
{
int c;
x &= 0xFFFFFFFFUL;
c = 0;
while ((x & 1) == 0) {
++c;
x >>= 1;
}
return c;
}
static void shift_xor(pmac_state *pmac)
{
int x, y;
y = ntz(pmac->block_index++);
for (x = 0; x < pmac->block_len; x++) {
pmac->Li[x] ^= pmac->Ls[y][x];
}
}
int pmac_process(pmac_state *state, const unsigned char *buf, unsigned long len)
{
int err, n, x;
unsigned char Z[MAXBLOCKSIZE];
_ARGCHK(state != NULL);
_ARGCHK(buf != NULL);
if ((err = cipher_is_valid(state->cipher_idx)) != CRYPT_OK) {
return err;
}
if ((state->buflen > (int)sizeof(state->block)) || (state->buflen < 0) ||
(state->block_len > (int)sizeof(state->block)) || (state->buflen > state->block_len)) {
return CRYPT_INVALID_ARG;
}
while (len != 0) {
/* ok if the block is full we xor in prev, encrypt and replace prev */
if (state->buflen == state->block_len) {
shift_xor(state);
for (x = 0; x < state->block_len; x++) {
Z[x] = state->Li[x] ^ state->block[x];
}
cipher_descriptor[state->cipher_idx].ecb_encrypt(Z, Z, &state->key);
for (x = 0; x < state->block_len; x++) {
state->checksum[x] ^= Z[x];
}
state->buflen = 0;
}
/* add bytes */
n = MIN(len, (unsigned long)(state->block_len - state->buflen));
memcpy(state->block + state->buflen, buf, n);
state->buflen += n;
len -= n;
buf += n;
}
#ifdef CLEAN_STACK
zeromem(Z, sizeof(Z));
#endif
return CRYPT_OK;
}
int pmac_done(pmac_state *state, unsigned char *out, unsigned long *outlen)
{
int err, x;
_ARGCHK(state != NULL);
_ARGCHK(out != NULL);
if ((err = cipher_is_valid(state->cipher_idx)) != CRYPT_OK) {
return err;
}
if ((state->buflen > (int)sizeof(state->block)) || (state->buflen < 0) ||
(state->block_len > (int)sizeof(state->block)) || (state->buflen > state->block_len)) {
return CRYPT_INVALID_ARG;
}
/* handle padding. If multiple xor in L/x */
if (state->buflen == state->block_len) {
/* xor Lr against the checksum */
for (x = 0; x < state->block_len; x++) {
state->checksum[x] ^= state->block[x] ^ state->Lr[x];
}
} else {
/* otherwise xor message bytes then the 0x80 byte */
for (x = 0; x < state->buflen; x++) {
state->checksum[x] ^= state->block[x];
}
state->checksum[x] ^= 0x80;
}
/* encrypt it */
cipher_descriptor[state->cipher_idx].ecb_encrypt(state->checksum, state->checksum, &state->key);
/* store it */
for (x = 0; x < state->block_len && x <= (int)*outlen; x++) {
out[x] = state->checksum[x];
}
*outlen = x;
#ifdef CLEAN_STACK
zeromem(state, sizeof(*state));
#endif
return CRYPT_OK;
}
int pmac_memory(int cipher, const unsigned char *key, unsigned long keylen,
const unsigned char *msg, unsigned long msglen,
unsigned char *out, unsigned long *outlen)
{
int err;
pmac_state pmac;
_ARGCHK(key != NULL);
_ARGCHK(msg != NULL);
_ARGCHK(out != NULL);
_ARGCHK(outlen != NULL);
if ((err = pmac_init(&pmac, cipher, key, keylen)) != CRYPT_OK) {
return err;
}
if ((err = pmac_process(&pmac, msg, msglen)) != CRYPT_OK) {
return err;
}
if ((err = pmac_done(&pmac, out, outlen)) != CRYPT_OK) {
return err;
}
return CRYPT_OK;
}
int pmac_file(int cipher, const unsigned char *key, unsigned long keylen,
const char *filename, unsigned char *out, unsigned long *outlen)
{
#ifdef NO_FILE
return CRYPT_NOP;
#else
int err, x;
pmac_state pmac;
FILE *in;
unsigned char buf[512];
_ARGCHK(key != NULL);
_ARGCHK(filename != NULL);
_ARGCHK(out != NULL);
_ARGCHK(outlen != NULL);
in = fopen(filename, "rb");
if (in == NULL) {
return CRYPT_FILE_NOTFOUND;
}
if ((err = pmac_init(&pmac, cipher, key, keylen)) != CRYPT_OK) {
fclose(in);
return err;
}
do {
x = fread(buf, 1, sizeof(buf), in);
if ((err = pmac_process(&pmac, buf, x)) != CRYPT_OK) {
fclose(in);
return err;
}
} while (x == sizeof(buf));
fclose(in);
if ((err = pmac_done(&pmac, out, outlen)) != CRYPT_OK) {
return err;
}
#ifdef CLEAN_STACK
zeromem(buf, sizeof(buf));
#endif
return CRYPT_OK;
#endif
}
int pmac_test(void)
{
#if !defined(LTC_TEST)
return CRYPT_NOP;
#else
static const struct {
int msglen;
unsigned char key[16], msg[34], tag[16];
} tests[] = {
/* PMAC-AES-128-0B */
{
0,
/* key */
{ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f },
/* msg */
{ 0x00 },
/* tag */
{ 0x43, 0x99, 0x57, 0x2c, 0xd6, 0xea, 0x53, 0x41,
0xb8, 0xd3, 0x58, 0x76, 0xa7, 0x09, 0x8a, 0xf7 }
},
/* PMAC-AES-128-3B */
{
3,
/* key */
{ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f },
/* msg */
{ 0x00, 0x01, 0x02 },
/* tag */
{ 0x25, 0x6b, 0xa5, 0x19, 0x3c, 0x1b, 0x99, 0x1b,
0x4d, 0xf0, 0xc5, 0x1f, 0x38, 0x8a, 0x9e, 0x27 }
},
/* PMAC-AES-128-16B */
{
16,
/* key */
{ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f },
/* msg */
{ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f },
/* tag */
{ 0xeb, 0xbd, 0x82, 0x2f, 0xa4, 0x58, 0xda, 0xf6,
0xdf, 0xda, 0xd7, 0xc2, 0x7d, 0xa7, 0x63, 0x38 }
},
/* PMAC-AES-128-20B */
{
20,
/* key */
{ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f },
/* msg */
{ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
0x10, 0x11, 0x12, 0x13 },
/* tag */
{ 0x04, 0x12, 0xca, 0x15, 0x0b, 0xbf, 0x79, 0x05,
0x8d, 0x8c, 0x75, 0xa5, 0x8c, 0x99, 0x3f, 0x55 }
},
/* PMAC-AES-128-32B */
{
32,
/* key */
{ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f },
/* msg */
{ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f },
/* tag */
{ 0xe9, 0x7a, 0xc0, 0x4e, 0x9e, 0x5e, 0x33, 0x99,
0xce, 0x53, 0x55, 0xcd, 0x74, 0x07, 0xbc, 0x75 }
},
/* PMAC-AES-128-34B */
{
34,
/* key */
{ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f },
/* msg */
{ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
0x20, 0x21 },
/* tag */
{ 0x5c, 0xba, 0x7d, 0x5e, 0xb2, 0x4f, 0x7c, 0x86,
0xcc, 0xc5, 0x46, 0x04, 0xe5, 0x3d, 0x55, 0x12 }
}
};
int err, x, idx;
unsigned long len;
unsigned char outtag[MAXBLOCKSIZE];
/* AES can be under rijndael or aes... try to find it */
if ((idx = find_cipher("aes")) == -1) {
if ((idx = find_cipher("rijndael")) == -1) {
return CRYPT_NOP;
}
}
for (x = 0; x < (int)(sizeof(tests)/sizeof(tests[0])); x++) {
len = sizeof(outtag);
if ((err = pmac_memory(idx, tests[x].key, 16, tests[x].msg, tests[x].msglen, outtag, &len)) != CRYPT_OK) {
return err;
}
if (memcmp(outtag, tests[x].tag, len)) {
#if 0
unsigned long y;
printf("\nTAG:\n");
for (y = 0; y < len; ) {
printf("0x%02x", outtag[y]);
if (y < len-1) printf(", ");
if (!(++y % 8)) printf("\n");
}
#endif
return CRYPT_FAIL_TESTVECTOR;
}
}
return CRYPT_OK;
#endif /* LTC_TEST */
}
#endif /* PMAC_MODE */