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#include "tomcrypt.h" 12f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 13f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project/** 14f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project @file ecb_decrypt.c 15f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project ECB implementation, decrypt a block, Tom St Denis 16f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project*/ 17f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 18f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project#ifdef LTC_ECB_MODE 19f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 20f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project/** 21f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project ECB decrypt 22f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project @param ct Ciphertext 23f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project @param pt [out] Plaintext 24f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project @param len The number of octets to process (must be multiple of the cipher block size) 25f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project @param ecb ECB state 26f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project @return CRYPT_OK if successful 27f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project*/ 28f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Projectint ecb_decrypt(const unsigned char *ct, unsigned char *pt, unsigned long len, symmetric_ECB *ecb) 29f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project{ 30f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project int err; 31f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project LTC_ARGCHK(pt != NULL); 32f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project LTC_ARGCHK(ct != NULL); 33f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project LTC_ARGCHK(ecb != NULL); 34f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project if ((err = cipher_is_valid(ecb->cipher)) != CRYPT_OK) { 35f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project return err; 36f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project } 37f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project if (len % cipher_descriptor[ecb->cipher].block_length) { 38f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project return CRYPT_INVALID_ARG; 39f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project } 40f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 41f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project /* check for accel */ 42f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project if (cipher_descriptor[ecb->cipher].accel_ecb_decrypt != NULL) { 43f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project return cipher_descriptor[ecb->cipher].accel_ecb_decrypt(ct, pt, len / cipher_descriptor[ecb->cipher].block_length, &ecb->key); 44f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project } else { 45f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project while (len) { 46f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project if ((err = cipher_descriptor[ecb->cipher].ecb_decrypt(ct, pt, &ecb->key)) != CRYPT_OK) { 47f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project return err; 48f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project } 49f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project pt += cipher_descriptor[ecb->cipher].block_length; 50f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project ct += cipher_descriptor[ecb->cipher].block_length; 51f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project len -= cipher_descriptor[ecb->cipher].block_length; 52f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project } 53f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project } 54f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project return CRYPT_OK; 55f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project} 56f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 57f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project#endif 58f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project 59f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project/* $Source: /cvs/libtom/libtomcrypt/src/modes/ecb/ecb_decrypt.c,v $ */ 60f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project/* $Revision: 1.9 $ */ 61f7fc46c63fdc8f39234fea409b8dbe116d73ebf8The Android Open Source Project/* $Date: 2006/06/29 01:51:34 $ */ 62