1 /* LibTomCrypt, modular cryptographic library -- Tom St Denis 2 * 3 * LibTomCrypt is a library that provides various cryptographic 4 * algorithms in a highly modular and flexible manner. 5 * 6 * The library is free for all purposes without any express 7 * guarantee it works. 8 * 9 * Tom St Denis, tomstdenis (at) gmail.com, http://libtomcrypt.com 10 */ 11 12 /** 13 @file eax_encrypt_authenticate_memory.c 14 EAX implementation, encrypt a block of memory, by Tom St Denis 15 */ 16 #include "tomcrypt.h" 17 18 #ifdef EAX_MODE 19 20 /** 21 EAX encrypt and produce an authentication tag 22 @param cipher The index of the cipher desired 23 @param key The secret key to use 24 @param keylen The length of the secret key (octets) 25 @param nonce The session nonce [use once] 26 @param noncelen The length of the nonce 27 @param header The header for the session 28 @param headerlen The length of the header (octets) 29 @param pt The plaintext 30 @param ptlen The length of the plaintext (octets) 31 @param ct [out] The ciphertext 32 @param tag [out] The destination tag 33 @param taglen [in/out] The max size and resulting size of the authentication tag 34 @return CRYPT_OK if successful 35 */ 36 int eax_encrypt_authenticate_memory(int cipher, 37 const unsigned char *key, unsigned long keylen, 38 const unsigned char *nonce, unsigned long noncelen, 39 const unsigned char *header, unsigned long headerlen, 40 const unsigned char *pt, unsigned long ptlen, 41 unsigned char *ct, 42 unsigned char *tag, unsigned long *taglen) 43 { 44 int err; 45 eax_state *eax; 46 47 LTC_ARGCHK(key != NULL); 48 LTC_ARGCHK(pt != NULL); 49 LTC_ARGCHK(ct != NULL); 50 LTC_ARGCHK(tag != NULL); 51 LTC_ARGCHK(taglen != NULL); 52 53 eax = XMALLOC(sizeof(*eax)); 54 55 if ((err = eax_init(eax, cipher, key, keylen, nonce, noncelen, header, headerlen)) != CRYPT_OK) { 56 goto LBL_ERR; 57 } 58 59 if ((err = eax_encrypt(eax, pt, ct, ptlen)) != CRYPT_OK) { 60 goto LBL_ERR; 61 } 62 63 if ((err = eax_done(eax, tag, taglen)) != CRYPT_OK) { 64 goto LBL_ERR; 65 } 66 67 err = CRYPT_OK; 68 LBL_ERR: 69 #ifdef LTC_CLEAN_STACK 70 zeromem(eax, sizeof(*eax)); 71 #endif 72 73 XFREE(eax); 74 75 return err; 76 } 77 78 #endif 79 80 /* $Source: /cvs/libtom/libtomcrypt/src/encauth/eax/eax_encrypt_authenticate_memory.c,v $ */ 81 /* $Revision: 1.4 $ */ 82 /* $Date: 2006/03/31 14:15:35 $ */ 83
