diff options
Diffstat (limited to 'libtomcrypt/src/encauth/ocb/ocb_encrypt_authenticate_memory.c')
-rw-r--r-- | libtomcrypt/src/encauth/ocb/ocb_encrypt_authenticate_memory.c | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/libtomcrypt/src/encauth/ocb/ocb_encrypt_authenticate_memory.c b/libtomcrypt/src/encauth/ocb/ocb_encrypt_authenticate_memory.c new file mode 100644 index 0000000..e58975e --- /dev/null +++ b/libtomcrypt/src/encauth/ocb/ocb_encrypt_authenticate_memory.c @@ -0,0 +1,84 @@ +/* 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.com + */ + +/** + @file ocb_encrypt_authenticate_memory.c + OCB implementation, encrypt block of memory, by Tom St Denis +*/ +#include "tomcrypt.h" + +#ifdef OCB_MODE + +/** + Encrypt and generate an authentication code for a buffer of memory + @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 ciphers block size) + @param pt The plaintext + @param ptlen The length of the plaintext (octets) + @param ct [out] The ciphertext + @param tag [out] The authentication tag + @param taglen [in/out] The max size and resulting size of the authentication tag + @return CRYPT_OK if successful +*/ +int ocb_encrypt_authenticate_memory(int cipher, + const unsigned char *key, unsigned long keylen, + const unsigned char *nonce, + const unsigned char *pt, unsigned long ptlen, + unsigned char *ct, + unsigned char *tag, unsigned long *taglen) +{ + 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(taglen != NULL); + + /* allocate ram */ + 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 (ptlen > (unsigned long)ocb->block_len) { + if ((err = ocb_encrypt(ocb, pt, ct)) != CRYPT_OK) { + goto LBL_ERR; + } + ptlen -= ocb->block_len; + pt += ocb->block_len; + ct += ocb->block_len; + } + + err = ocb_done_encrypt(ocb, pt, ptlen, ct, tag, taglen); +LBL_ERR: +#ifdef LTC_CLEAN_STACK + zeromem(ocb, sizeof(ocb_state)); +#endif + + XFREE(ocb); + + return err; +} + +#endif + +/* $Source: /cvs/libtom/libtomcrypt/src/encauth/ocb/ocb_encrypt_authenticate_memory.c,v $ */ +/* $Revision: 1.4 $ */ +/* $Date: 2006/03/31 14:15:35 $ */ |