1ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta/* 2ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta --------------------------------------------------------------------------- 3ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta Copyright (c) 1998-2008, Brian Gladman, Worcester, UK. All rights reserved. 4ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta 5ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta LICENSE TERMS 6ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta 7ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta The redistribution and use of this software (with or without changes) 8ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta is allowed without the payment of fees or royalties provided that: 9ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta 10ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta 1. source code distributions include the above copyright notice, this 11ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta list of conditions and the following disclaimer; 12ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta 13ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta 2. binary distributions include the above copyright notice, this list 14ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta of conditions and the following disclaimer in their documentation; 15ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta 16ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta 3. the name of the copyright holder is not used to endorse products 17ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta built using this software without specific written permission. 18ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta 19ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta DISCLAIMER 20ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta 21ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta This software is provided 'as is' with no explicit or implied warranties 22ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta in respect of its properties, including, but not limited to, correctness 23ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta and/or fitness for purpose. 24ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta --------------------------------------------------------------------------- 25ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta Issue 09/09/2006 26ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta 27ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta This is an AES implementation that uses only 8-bit byte operations on the 28ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta cipher state. 29ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta */ 30ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta 31ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta#ifndef AES_H 32ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta#define AES_H 33ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta 34ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta#if 1 35ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta# define AES_ENC_PREKEYED /* AES encryption with a precomputed key schedule */ 36ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta#endif 37ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta#if 1 38ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta# define AES_DEC_PREKEYED /* AES decryption with a precomputed key schedule */ 39ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta#endif 40ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta#if 1 41ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta# define AES_ENC_128_OTFK /* AES encryption with 'on the fly' 128 bit keying */ 42ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta#endif 43ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta#if 1 44ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta# define AES_DEC_128_OTFK /* AES decryption with 'on the fly' 128 bit keying */ 45ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta#endif 46ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta#if 1 47ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta# define AES_ENC_256_OTFK /* AES encryption with 'on the fly' 256 bit keying */ 48ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta#endif 49ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta#if 1 50ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta# define AES_DEC_256_OTFK /* AES decryption with 'on the fly' 256 bit keying */ 51ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta#endif 52ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta 53ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta#define N_ROW 4 54ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta#define N_COL 4 55ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta#define N_BLOCK (N_ROW * N_COL) 56ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta#define N_MAX_ROUNDS 14 57ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta 58ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Battatypedef unsigned char uint_8t; 59ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta 60ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Battatypedef uint_8t return_type; 61ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta 62ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta/* Warning: The key length for 256 bit keys overflows a byte 63ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta (see comment below) 64ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta*/ 65ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta 66ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Battatypedef uint_8t length_type; 67ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta 68ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Battatypedef struct 69ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta{ uint_8t ksch[(N_MAX_ROUNDS + 1) * N_BLOCK]; 70ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta uint_8t rnd; 71ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta} aes_context; 72ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta 73ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta/* The following calls are for a precomputed key schedule 74ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta 75ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta NOTE: If the length_type used for the key length is an 76ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta unsigned 8-bit character, a key length of 256 bits must 77ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta be entered as a length in bytes (valid inputs are hence 78ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta 128, 192, 16, 24 and 32). 79ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta*/ 80ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta 81ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta#if defined( AES_ENC_PREKEYED ) || defined( AES_DEC_PREKEYED ) 82ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta 83ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Battareturn_type aes_set_key( const unsigned char key[], 84ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta length_type keylen, 85ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta aes_context ctx[1] ); 86ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta#endif 87ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta 88ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta#if defined( AES_ENC_PREKEYED ) 89ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta 90ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Battareturn_type aes_encrypt( const unsigned char in[N_BLOCK], 91ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta unsigned char out[N_BLOCK], 92ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta const aes_context ctx[1] ); 93ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta 94ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Battareturn_type aes_cbc_encrypt( const unsigned char *in, 95ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta unsigned char *out, 96ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta int n_block, 97ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta unsigned char iv[N_BLOCK], 98ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta const aes_context ctx[1] ); 99ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta#endif 100ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta 101ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta#if defined( AES_DEC_PREKEYED ) 102ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta 103ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Battareturn_type aes_decrypt( const unsigned char in[N_BLOCK], 104ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta unsigned char out[N_BLOCK], 105ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta const aes_context ctx[1] ); 106ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta 107ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Battareturn_type aes_cbc_decrypt( const unsigned char *in, 108ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta unsigned char *out, 109ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta int n_block, 110ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta unsigned char iv[N_BLOCK], 111ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta const aes_context ctx[1] ); 112ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta#endif 113ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta 114ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta/* The following calls are for 'on the fly' keying. In this case the 115ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta encryption and decryption keys are different. 116ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta 117ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta The encryption subroutines take a key in an array of bytes in 118ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta key[L] where L is 16, 24 or 32 bytes for key lengths of 128, 119ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta 192, and 256 bits respectively. They then encrypts the input 120ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta data, in[] with this key and put the reult in the output array 121ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta out[]. In addition, the second key array, o_key[L], is used 122ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta to output the key that is needed by the decryption subroutine 123ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta to reverse the encryption operation. The two key arrays can 124ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta be the same array but in this case the original key will be 125ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta overwritten. 126ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta 127ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta In the same way, the decryption subroutines output keys that 128ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta can be used to reverse their effect when used for encryption. 129ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta 130ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta Only 128 and 256 bit keys are supported in these 'on the fly' 131ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta modes. 132ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta*/ 133ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta 134ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta#if defined( AES_ENC_128_OTFK ) 135ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Battavoid aes_encrypt_128( const unsigned char in[N_BLOCK], 136ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta unsigned char out[N_BLOCK], 137ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta const unsigned char key[N_BLOCK], 138ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta uint_8t o_key[N_BLOCK] ); 139ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta#endif 140ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta 141ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta#if defined( AES_DEC_128_OTFK ) 142ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Battavoid aes_decrypt_128( const unsigned char in[N_BLOCK], 143ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta unsigned char out[N_BLOCK], 144ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta const unsigned char key[N_BLOCK], 145ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta unsigned char o_key[N_BLOCK] ); 146ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta#endif 147ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta 148ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta#if defined( AES_ENC_256_OTFK ) 149ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Battavoid aes_encrypt_256( const unsigned char in[N_BLOCK], 150ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta unsigned char out[N_BLOCK], 151ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta const unsigned char key[2 * N_BLOCK], 152ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta unsigned char o_key[2 * N_BLOCK] ); 153ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta#endif 154ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta 155ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta#if defined( AES_DEC_256_OTFK ) 156ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Battavoid aes_decrypt_256( const unsigned char in[N_BLOCK], 157ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta unsigned char out[N_BLOCK], 158ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta const unsigned char key[2 * N_BLOCK], 159ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta unsigned char o_key[2 * N_BLOCK] ); 160ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta#endif 161ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta 162ead3cde4bac0c3e32cd31f149093f004eef8ceebGanesh Ganapathi Batta#endif 163