xref: /openbmc/u-boot/include/uboot_aes.h (revision ebce73f0)
1 /*
2  * Copyright (c) 2011 The Chromium OS Authors.
3  * (C) Copyright 2010 - 2011 NVIDIA Corporation <www.nvidia.com>
4  *
5  * SPDX-License-Identifier:	GPL-2.0+
6  */
7 
8 #ifndef _AES_REF_H_
9 #define _AES_REF_H_
10 
11 #ifdef USE_HOSTCC
12 /* Define compat stuff for use in fw_* tools. */
13 typedef unsigned char u8;
14 typedef unsigned int u32;
15 #define debug(...) do {} while (0)
16 #endif
17 
18 /*
19  * AES encryption library, with small code size, supporting only 128-bit AES
20  *
21  * AES is a stream cipher which works a block at a time, with each block
22  * in this case being AES_KEY_LENGTH bytes.
23  */
24 
25 enum {
26 	AES_STATECOLS	= 4,	/* columns in the state & expanded key */
27 	AES_KEYCOLS	= 4,	/* columns in a key */
28 	AES_ROUNDS	= 10,	/* rounds in encryption */
29 
30 	AES_KEY_LENGTH	= 128 / 8,
31 	AES_EXPAND_KEY_LENGTH	= 4 * AES_STATECOLS * (AES_ROUNDS + 1),
32 };
33 
34 /**
35  * aes_expand_key() - Expand the AES key
36  *
37  * Expand a key into a key schedule, which is then used for the other
38  * operations.
39  *
40  * @key		Key, of length AES_KEY_LENGTH bytes
41  * @expkey	Buffer to place expanded key, AES_EXPAND_KEY_LENGTH
42  */
43 void aes_expand_key(u8 *key, u8 *expkey);
44 
45 /**
46  * aes_encrypt() - Encrypt single block of data with AES 128
47  *
48  * @in		Input data
49  * @expkey	Expanded key to use for encryption (from aes_expand_key())
50  * @out		Output data
51  */
52 void aes_encrypt(u8 *in, u8 *expkey, u8 *out);
53 
54 /**
55  * aes_decrypt() - Decrypt single block of data with AES 128
56  *
57  * @in		Input data
58  * @expkey	Expanded key to use for decryption (from aes_expand_key())
59  * @out		Output data
60  */
61 void aes_decrypt(u8 *in, u8 *expkey, u8 *out);
62 
63 /**
64  * Apply chain data to the destination using EOR
65  *
66  * Each array is of length AES_KEY_LENGTH.
67  *
68  * @cbc_chain_data	Chain data
69  * @src			Source data
70  * @dst			Destination data, which is modified here
71  */
72 void aes_apply_cbc_chain_data(u8 *cbc_chain_data, u8 *src, u8 *dst);
73 
74 /**
75  * aes_cbc_encrypt_blocks() - Encrypt multiple blocks of data with AES CBC.
76  *
77  * @key_exp		Expanded key to use
78  * @iv			Initialization vector
79  * @src			Source data to encrypt
80  * @dst			Destination buffer
81  * @num_aes_blocks	Number of AES blocks to encrypt
82  */
83 void aes_cbc_encrypt_blocks(u8 *key_exp, u8 *iv, u8 *src, u8 *dst,
84 			    u32 num_aes_blocks);
85 
86 /**
87  * Decrypt multiple blocks of data with AES CBC.
88  *
89  * @key_exp		Expanded key to use
90  * @iv			Initialization vector
91  * @src			Source data to decrypt
92  * @dst			Destination buffer
93  * @num_aes_blocks	Number of AES blocks to decrypt
94  */
95 void aes_cbc_decrypt_blocks(u8 *key_exp, u8 *iv, u8 *src, u8 *dst,
96 			    u32 num_aes_blocks);
97 
98 #endif /* _AES_REF_H_ */
99