diff options
Diffstat (limited to 'src/mac/pelican/pelican.c')
| -rw-r--r-- | src/mac/pelican/pelican.c | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/src/mac/pelican/pelican.c b/src/mac/pelican/pelican.c new file mode 100644 index 0000000..85bf9ee --- /dev/null +++ b/src/mac/pelican/pelican.c @@ -0,0 +1,165 @@ +/* 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.org + */ +#include "tomcrypt.h" + +/** + @file pelican.c + Pelican MAC, initialize state, by Tom St Denis +*/ + +#ifdef PELICAN + +#define ENCRYPT_ONLY +#include "../../ciphers/aes/aes_tab.c" + + +/** + Initialize a Pelican state + @param pelmac The Pelican state to initialize + @param key The secret key + @param keylen The length of the secret key (octets) + @return CRYPT_OK if successful +*/ +int pelican_init(pelican_state *pelmac, const unsigned char *key, unsigned long keylen) +{ + int err; + + LTC_ARGCHK(pelmac != NULL); + LTC_ARGCHK(key != NULL); + +#ifdef LTC_FAST + if (16 % sizeof(LTC_FAST_TYPE)) { + return CRYPT_INVALID_ARG; + } +#endif + + if ((err = aes_setup(key, keylen, 0, &pelmac->K)) != CRYPT_OK) { + return err; + } + + zeromem(pelmac->state, 16); + aes_ecb_encrypt(pelmac->state, pelmac->state, &pelmac->K); + pelmac->buflen = 0; + + return CRYPT_OK; +} + +static void four_rounds(pelican_state *pelmac) +{ + ulong32 s0, s1, s2, s3, t0, t1, t2, t3; + int r; + + LOAD32H(s0, pelmac->state ); + LOAD32H(s1, pelmac->state + 4); + LOAD32H(s2, pelmac->state + 8); + LOAD32H(s3, pelmac->state + 12); + for (r = 0; r < 4; r++) { + t0 = + Te0(byte(s0, 3)) ^ + Te1(byte(s1, 2)) ^ + Te2(byte(s2, 1)) ^ + Te3(byte(s3, 0)); + t1 = + Te0(byte(s1, 3)) ^ + Te1(byte(s2, 2)) ^ + Te2(byte(s3, 1)) ^ + Te3(byte(s0, 0)); + t2 = + Te0(byte(s2, 3)) ^ + Te1(byte(s3, 2)) ^ + Te2(byte(s0, 1)) ^ + Te3(byte(s1, 0)); + t3 = + Te0(byte(s3, 3)) ^ + Te1(byte(s0, 2)) ^ + Te2(byte(s1, 1)) ^ + Te3(byte(s2, 0)); + s0 = t0; s1 = t1; s2 = t2; s3 = t3; + } + STORE32H(s0, pelmac->state ); + STORE32H(s1, pelmac->state + 4); + STORE32H(s2, pelmac->state + 8); + STORE32H(s3, pelmac->state + 12); +} + +/** + Process a block of text through Pelican + @param pelmac The Pelican MAC state + @param in The input + @param inlen The length input (octets) + @return CRYPT_OK on success + */ +int pelican_process(pelican_state *pelmac, const unsigned char *in, unsigned long inlen) +{ + + LTC_ARGCHK(pelmac != NULL); + LTC_ARGCHK(in != NULL); + + /* check range */ + if (pelmac->buflen < 0 || pelmac->buflen > 15) { + return CRYPT_INVALID_ARG; + } + +#ifdef LTC_FAST + if (pelmac->buflen == 0) { + while (inlen & ~15) { + int x; + for (x = 0; x < 16; x += sizeof(LTC_FAST_TYPE)) { + *((LTC_FAST_TYPE*)((unsigned char *)pelmac->state + x)) ^= *((LTC_FAST_TYPE*)((unsigned char *)in + x)); + } + four_rounds(pelmac); + in += 16; + inlen -= 16; + } + } +#endif + + while (inlen--) { + pelmac->state[pelmac->buflen++] ^= *in++; + if (pelmac->buflen == 16) { + four_rounds(pelmac); + pelmac->buflen = 0; + } + } + return CRYPT_OK; +} + +/** + Terminate Pelican MAC + @param pelmac The Pelican MAC state + @param out [out] The TAG + @return CRYPT_OK on sucess +*/ +int pelican_done(pelican_state *pelmac, unsigned char *out) +{ + LTC_ARGCHK(pelmac != NULL); + LTC_ARGCHK(out != NULL); + + /* check range */ + if (pelmac->buflen < 0 || pelmac->buflen > 16) { + return CRYPT_INVALID_ARG; + } + + if (pelmac->buflen == 16) { + four_rounds(pelmac); + pelmac->buflen = 0; + } + pelmac->state[pelmac->buflen++] ^= 0x80; + aes_ecb_encrypt(pelmac->state, out, &pelmac->K); + aes_done(&pelmac->K); + return CRYPT_OK; +} + +#endif + +/* $Source: /cvs/libtom/libtomcrypt/src/mac/pelican/pelican.c,v $ */ +/* $Revision: 1.16 $ */ +/* $Date: 2005/05/05 14:35:59 $ */ |