1 /* SPDX-License-Identifier: GPL-2.0+ */ 2 /* 3 * Copyright (c) 2011 The Chromium OS Authors. 4 * (C) Copyright 2010 - 2011 NVIDIA Corporation <www.nvidia.com> 5 */ 6 7 #ifndef _AES_REF_H_ 8 #define _AES_REF_H_ 9 10 #ifdef USE_HOSTCC 11 /* Define compat stuff for use in fw_* tools. */ 12 typedef unsigned char u8; 13 typedef unsigned int u32; 14 #define debug(...) do {} while (0) 15 #endif 16 17 /* 18 * AES encryption library, with small code size, supporting only 128-bit AES 19 * 20 * AES is a stream cipher which works a block at a time, with each block 21 * in this case being AES_KEY_LENGTH bytes. 22 */ 23 24 enum { 25 AES_STATECOLS = 4, /* columns in the state & expanded key */ 26 AES_KEYCOLS = 4, /* columns in a key */ 27 AES_ROUNDS = 10, /* rounds in encryption */ 28 29 AES_KEY_LENGTH = 128 / 8, 30 AES_EXPAND_KEY_LENGTH = 4 * AES_STATECOLS * (AES_ROUNDS + 1), 31 }; 32 33 /** 34 * aes_expand_key() - Expand the AES key 35 * 36 * Expand a key into a key schedule, which is then used for the other 37 * operations. 38 * 39 * @key Key, of length AES_KEY_LENGTH bytes 40 * @expkey Buffer to place expanded key, AES_EXPAND_KEY_LENGTH 41 */ 42 void aes_expand_key(u8 *key, u8 *expkey); 43 44 /** 45 * aes_encrypt() - Encrypt single block of data with AES 128 46 * 47 * @in Input data 48 * @expkey Expanded key to use for encryption (from aes_expand_key()) 49 * @out Output data 50 */ 51 void aes_encrypt(u8 *in, u8 *expkey, u8 *out); 52 53 /** 54 * aes_decrypt() - Decrypt single block of data with AES 128 55 * 56 * @in Input data 57 * @expkey Expanded key to use for decryption (from aes_expand_key()) 58 * @out Output data 59 */ 60 void aes_decrypt(u8 *in, u8 *expkey, u8 *out); 61 62 /** 63 * Apply chain data to the destination using EOR 64 * 65 * Each array is of length AES_KEY_LENGTH. 66 * 67 * @cbc_chain_data Chain data 68 * @src Source data 69 * @dst Destination data, which is modified here 70 */ 71 void aes_apply_cbc_chain_data(u8 *cbc_chain_data, u8 *src, u8 *dst); 72 73 /** 74 * aes_cbc_encrypt_blocks() - Encrypt multiple blocks of data with AES CBC. 75 * 76 * @key_exp Expanded key to use 77 * @iv Initialization vector 78 * @src Source data to encrypt 79 * @dst Destination buffer 80 * @num_aes_blocks Number of AES blocks to encrypt 81 */ 82 void aes_cbc_encrypt_blocks(u8 *key_exp, u8 *iv, u8 *src, u8 *dst, 83 u32 num_aes_blocks); 84 85 /** 86 * Decrypt multiple blocks of data with AES CBC. 87 * 88 * @key_exp Expanded key to use 89 * @iv Initialization vector 90 * @src Source data to decrypt 91 * @dst Destination buffer 92 * @num_aes_blocks Number of AES blocks to decrypt 93 */ 94 void aes_cbc_decrypt_blocks(u8 *key_exp, u8 *iv, u8 *src, u8 *dst, 95 u32 num_aes_blocks); 96 97 #endif /* _AES_REF_H_ */ 98