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. */
12typedef unsigned char u8;
13typedef 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_BLOCK_LENGTH bytes.
22 */
23
24enum {
25	AES_STATECOLS	= 4,	/* columns in the state & expanded key */
26	AES128_KEYCOLS	= 4,	/* columns in a key for aes128 */
27	AES192_KEYCOLS	= 6,	/* columns in a key for aes128 */
28	AES256_KEYCOLS	= 8,	/* columns in a key for aes128 */
29	AES128_ROUNDS	= 10,	/* rounds in encryption for aes128 */
30	AES192_ROUNDS	= 12,	/* rounds in encryption for aes192 */
31	AES256_ROUNDS	= 14,	/* rounds in encryption for aes256 */
32	AES128_KEY_LENGTH	= 128 / 8,
33	AES192_KEY_LENGTH	= 192 / 8,
34	AES256_KEY_LENGTH	= 256 / 8,
35	AES128_EXPAND_KEY_LENGTH = 4 * AES_STATECOLS * (AES128_ROUNDS + 1),
36	AES192_EXPAND_KEY_LENGTH = 4 * AES_STATECOLS * (AES192_ROUNDS + 1),
37	AES256_EXPAND_KEY_LENGTH = 4 * AES_STATECOLS * (AES256_ROUNDS + 1),
38	AES_BLOCK_LENGTH	= 128 / 8,
39};
40
41/**
42 * aes_expand_key() - Expand the AES key
43 *
44 * Expand a key into a key schedule, which is then used for the other
45 * operations.
46 *
47 * @key		Key
48 * @key_size	Size of the key (in bits)
49 * @expkey	Buffer to place expanded key, AES_EXPAND_KEY_LENGTH
50 */
51void aes_expand_key(u8 *key, u32 key_size, u8 *expkey);
52
53/**
54 * aes_encrypt() - Encrypt single block of data with AES 128
55 *
56 * @key_size	Size of the aes key (in bits)
57 * @in		Input data
58 * @expkey	Expanded key to use for encryption (from aes_expand_key())
59 * @out		Output data
60 */
61void aes_encrypt(u32 key_size, u8 *in, u8 *expkey, u8 *out);
62
63/**
64 * aes_decrypt() - Decrypt single block of data with AES 128
65 *
66 * @key_size	Size of the aes key (in bits)
67 * @in		Input data
68 * @expkey	Expanded key to use for decryption (from aes_expand_key())
69 * @out		Output data
70 */
71void aes_decrypt(u32 key_size, u8 *in, u8 *expkey, u8 *out);
72
73/**
74 * Apply chain data to the destination using EOR
75 *
76 * Each array is of length AES_BLOCK_LENGTH.
77 *
78 * @cbc_chain_data	Chain data
79 * @src			Source data
80 * @dst			Destination data, which is modified here
81 */
82void aes_apply_cbc_chain_data(u8 *cbc_chain_data, u8 *src, u8 *dst);
83
84/**
85 * aes_cbc_encrypt_blocks() - Encrypt multiple blocks of data with AES CBC.
86 *
87 * @key_size		Size of the aes key (in bits)
88 * @key_exp		Expanded key to use
89 * @iv			Initialization vector
90 * @src			Source data to encrypt
91 * @dst			Destination buffer
92 * @num_aes_blocks	Number of AES blocks to encrypt
93 */
94void aes_cbc_encrypt_blocks(u32 key_size, u8 *key_exp, u8 *iv, u8 *src, u8 *dst,
95			    u32 num_aes_blocks);
96
97/**
98 * Decrypt multiple blocks of data with AES CBC.
99 *
100 * @key_size		Size of the aes key (in bits)
101 * @key_exp		Expanded key to use
102 * @iv			Initialization vector
103 * @src			Source data to decrypt
104 * @dst			Destination buffer
105 * @num_aes_blocks	Number of AES blocks to decrypt
106 */
107void aes_cbc_decrypt_blocks(u32 key_size, u8 *key_exp, u8 *iv, u8 *src, u8 *dst,
108			    u32 num_aes_blocks);
109
110#endif /* _AES_REF_H_ */
111