diff options
Diffstat (limited to 'libtomcrypt/src/mac/pmac/pmac_init.c')
| -rw-r--r-- | libtomcrypt/src/mac/pmac/pmac_init.c | 147 |
1 files changed, 147 insertions, 0 deletions
diff --git a/libtomcrypt/src/mac/pmac/pmac_init.c b/libtomcrypt/src/mac/pmac/pmac_init.c new file mode 100644 index 0000000..c842160 --- /dev/null +++ b/libtomcrypt/src/mac/pmac/pmac_init.c @@ -0,0 +1,147 @@ +/* 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@gmail.com, http://libtomcrypt.com + */ +#include "tomcrypt.h" + +/** + @file pmac_init.c + PMAC implementation, initialize state, by Tom St Denis +*/ + +#ifdef LTC_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 } +} +}; + +/** + Initialize a PMAC state + @param pmac The PMAC state to initialize + @param cipher The index of the desired cipher + @param key The secret key + @param keylen The length of the secret key (octets) + @return CRYPT_OK if successful +*/ +int pmac_init(pmac_state *pmac, int cipher, const unsigned char *key, unsigned long keylen) +{ + int poly, x, y, m, err; + unsigned char *L; + + LTC_ARGCHK(pmac != NULL); + LTC_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; + } + +#ifdef LTC_FAST + if (pmac->block_len % sizeof(LTC_FAST_TYPE)) { + return CRYPT_INVALID_ARG; + } +#endif + + + /* schedule the key */ + if ((err = cipher_descriptor[cipher].setup(key, keylen, 0, &pmac->key)) != CRYPT_OK) { + return err; + } + + /* allocate L */ + L = XMALLOC(pmac->block_len); + if (L == NULL) { + return CRYPT_MEM; + } + + /* find L = E[0] */ + zeromem(L, pmac->block_len); + if ((err = cipher_descriptor[cipher].ecb_encrypt(L, L, &pmac->key)) != CRYPT_OK) { + goto error; + } + + /* find Ls[i] = L << i for i == 0..31 */ + XMEMCPY(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)); + err = CRYPT_OK; +error: +#ifdef LTC_CLEAN_STACK + zeromem(L, pmac->block_len); +#endif + + XFREE(L); + + return err; +} + +#endif + +/* $Source: /cvs/libtom/libtomcrypt/src/mac/pmac/pmac_init.c,v $ */ +/* $Revision: 1.7 $ */ +/* $Date: 2006/11/03 00:39:49 $ */ |