| // SPDX-License-Identifier: BSD-2-Clause |
| /* 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. |
| */ |
| #include "tomcrypt_private.h" |
| |
| #ifdef LTC_CCM_MODE |
| |
| /** |
| Add AAD to the CCM state |
| @param ccm The CCM state |
| @param adata The additional authentication data to add to the CCM state |
| @param adatalen The length of the AAD data. |
| @return CRYPT_OK on success |
| */ |
| int ccm_add_aad(ccm_state *ccm, |
| const unsigned char *adata, unsigned long adatalen) |
| { |
| unsigned long y; |
| int err; |
| |
| LTC_ARGCHK(ccm != NULL); |
| LTC_ARGCHK(adata != NULL); |
| |
| if (ccm->aadlen < ccm->current_aadlen + adatalen) { |
| return CRYPT_INVALID_ARG; |
| } |
| ccm->current_aadlen += adatalen; |
| |
| /* now add the data */ |
| for (y = 0; y < adatalen; y++) { |
| if (ccm->x == 16) { |
| /* full block so let's encrypt it */ |
| if ((err = cipher_descriptor[ccm->cipher]->ecb_encrypt(ccm->PAD, ccm->PAD, &ccm->K)) != CRYPT_OK) { |
| return err; |
| } |
| ccm->x = 0; |
| } |
| ccm->PAD[ccm->x++] ^= adata[y]; |
| } |
| |
| /* remainder? */ |
| if (ccm->aadlen == ccm->current_aadlen) { |
| if (ccm->x != 0) { |
| if ((err = cipher_descriptor[ccm->cipher]->ecb_encrypt(ccm->PAD, ccm->PAD, &ccm->K)) != CRYPT_OK) { |
| return err; |
| } |
| } |
| ccm->x = 0; |
| } |
| |
| return CRYPT_OK; |
| } |
| |
| #endif |
| |
| /* ref: $Format:%D$ */ |
| /* git commit: $Format:%H$ */ |
| /* commit time: $Format:%ai$ */ |