Mercurial > dropbear
view libtomcrypt/src/encauth/ccm/ccm_process.c @ 1746:28ab2cdb84bf
Fix fuzzer build
author | Matt Johnston <matt@ucc.asn.au> |
---|---|
date | Sun, 18 Oct 2020 23:32:39 +0800 |
parents | 6dba84798cd5 |
children |
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/* 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.h" #ifdef LTC_CCM_MODE /** Process plaintext/ciphertext through CCM @param ccm The CCM state @param pt The plaintext @param ptlen The plaintext length (ciphertext length is the same) @param ct The ciphertext @param direction Encrypt or Decrypt mode (CCM_ENCRYPT or CCM_DECRYPT) @return CRYPT_OK on success */ int ccm_process(ccm_state *ccm, unsigned char *pt, unsigned long ptlen, unsigned char *ct, int direction) { unsigned char z, b; unsigned long y; int err; LTC_ARGCHK(ccm != NULL); /* Check aad has been correctly added */ if (ccm->aadlen != ccm->current_aadlen) { return CRYPT_ERROR; } /* Check we do not process too much data */ if (ccm->ptlen < ccm->current_ptlen + ptlen) { return CRYPT_ERROR; } ccm->current_ptlen += ptlen; /* now handle the PT */ if (ptlen > 0) { LTC_ARGCHK(pt != NULL); LTC_ARGCHK(ct != NULL); for (y = 0; y < ptlen; y++) { /* increment the ctr? */ if (ccm->CTRlen == 16) { for (z = 15; z > 15-ccm->L; z--) { ccm->ctr[z] = (ccm->ctr[z] + 1) & 255; if (ccm->ctr[z]) break; } if ((err = cipher_descriptor[ccm->cipher].ecb_encrypt(ccm->ctr, ccm->CTRPAD, &ccm->K)) != CRYPT_OK) { return err; } ccm->CTRlen = 0; } /* if we encrypt we add the bytes to the MAC first */ if (direction == CCM_ENCRYPT) { b = pt[y]; ct[y] = b ^ ccm->CTRPAD[ccm->CTRlen++]; } else { b = ct[y] ^ ccm->CTRPAD[ccm->CTRlen++]; pt[y] = b; } if (ccm->x == 16) { 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++] ^= b; } } return CRYPT_OK; } #endif /* ref: $Format:%D$ */ /* git commit: $Format:%H$ */ /* commit time: $Format:%ai$ */