1f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project/* LibTomCrypt, modular cryptographic library -- Tom St Denis 2f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project * 3f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project * LibTomCrypt is a library that provides various cryptographic 4f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project * algorithms in a highly modular and flexible manner. 5f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project * 6f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project * The library is free for all purposes without any express 7f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project * guarantee it works. 8f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project * 9f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project * Tom St Denis, tomstdenis@gmail.com, http://libtomcrypt.com 10f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project */ 11f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 12f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project/** 13f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project @file eax_decrypt.c 14f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project EAX implementation, decrypt block, by Tom St Denis 15f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project*/ 16f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project#include "tomcrypt.h" 17f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 18f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project#ifdef EAX_MODE 19f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 20f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project/** 21f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project Decrypt data with the EAX protocol 22f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project @param eax The EAX state 23f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project @param ct The ciphertext 24f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project @param pt [out] The plaintext 25f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project @param length The length (octets) of the ciphertext 26f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project @return CRYPT_OK if successful 27f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project*/ 28f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Projectint eax_decrypt(eax_state *eax, const unsigned char *ct, unsigned char *pt, 29f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project unsigned long length) 30f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project{ 31f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project int err; 32f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 33f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project LTC_ARGCHK(eax != NULL); 34f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project LTC_ARGCHK(pt != NULL); 35f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project LTC_ARGCHK(ct != NULL); 36f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 37f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project /* omac ciphertext */ 38f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project if ((err = omac_process(&eax->ctomac, ct, length)) != CRYPT_OK) { 39f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project return err; 40f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project } 41f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 42f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project /* decrypt */ 43f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project return ctr_decrypt(ct, pt, length, &eax->ctr); 44f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project} 45f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 46f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project#endif 47f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 48f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project/* $Source: /cvs/libtom/libtomcrypt/src/encauth/eax/eax_decrypt.c,v $ */ 49f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project/* $Revision: 1.4 $ */ 50f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project/* $Date: 2006/03/31 14:15:35 $ */ 51