Mercurial > dropbear
view libtomcrypt/src/encauth/ocb/ocb_decrypt_verify_memory.c @ 1481:515f37a55cd2
exclude clang rather than osx for unbundled libtom
author | Matt Johnston <matt@ucc.asn.au> |
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date | Sat, 10 Feb 2018 00:09:02 +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. */ /** @file ocb_decrypt_verify_memory.c OCB implementation, helper to decrypt block of memory, by Tom St Denis */ #include "tomcrypt.h" #ifdef LTC_OCB_MODE /** Decrypt and compare the tag with OCB. @param cipher The index of the cipher desired @param key The secret key @param keylen The length of the secret key (octets) @param nonce The session nonce (length of the block size of the block cipher) @param ct The ciphertext @param ctlen The length of the ciphertext (octets) @param pt [out] The plaintext @param tag The tag to compare against @param taglen The length of the tag (octets) @param stat [out] The result of the tag comparison (1==valid, 0==invalid) @return CRYPT_OK if successful regardless of the tag comparison */ int ocb_decrypt_verify_memory(int cipher, const unsigned char *key, unsigned long keylen, const unsigned char *nonce, const unsigned char *ct, unsigned long ctlen, unsigned char *pt, const unsigned char *tag, unsigned long taglen, int *stat) { int err; ocb_state *ocb; LTC_ARGCHK(key != NULL); LTC_ARGCHK(nonce != NULL); LTC_ARGCHK(pt != NULL); LTC_ARGCHK(ct != NULL); LTC_ARGCHK(tag != NULL); LTC_ARGCHK(stat != NULL); /* allocate memory */ ocb = XMALLOC(sizeof(ocb_state)); if (ocb == NULL) { return CRYPT_MEM; } if ((err = ocb_init(ocb, cipher, key, keylen, nonce)) != CRYPT_OK) { goto LBL_ERR; } while (ctlen > (unsigned long)ocb->block_len) { if ((err = ocb_decrypt(ocb, ct, pt)) != CRYPT_OK) { goto LBL_ERR; } ctlen -= ocb->block_len; pt += ocb->block_len; ct += ocb->block_len; } err = ocb_done_decrypt(ocb, ct, ctlen, pt, tag, taglen, stat); LBL_ERR: #ifdef LTC_CLEAN_STACK zeromem(ocb, sizeof(ocb_state)); #endif XFREE(ocb); return err; } #endif /* ref: $Format:%D$ */ /* git commit: $Format:%H$ */ /* commit time: $Format:%ai$ */