| /* 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 pmac_done.c |
| PMAC implementation, terminate a session, by Tom St Denis |
| */ |
| |
| #ifdef PMAC |
| |
| int pmac_done(pmac_state *state, unsigned char *out, unsigned long *outlen) |
| { |
| int err, x; |
| |
| LTC_ARGCHK(state != NULL); |
| LTC_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); |
| cipher_descriptor[state->cipher_idx].done(&state->key); |
| |
| /* store it */ |
| for (x = 0; x < state->block_len && x <= (int)*outlen; x++) { |
| out[x] = state->checksum[x]; |
| } |
| *outlen = x; |
| |
| #ifdef LTC_CLEAN_STACK |
| zeromem(state, sizeof(*state)); |
| #endif |
| return CRYPT_OK; |
| } |
| |
| #endif |
| |