xref: /openbmc/u-boot/cmd/aes.c (revision aa5e3e22)
1 /*
2  * Copyright (C) 2014 Marek Vasut <marex@denx.de>
3  *
4  * Command for en/de-crypting block of memory with AES-128-CBC cipher.
5  *
6  * SPDX-License-Identifier:	GPL-2.0+
7  */
8 
9 #include <common.h>
10 #include <command.h>
11 #include <environment.h>
12 #include <uboot_aes.h>
13 #include <malloc.h>
14 #include <asm/byteorder.h>
15 #include <linux/compiler.h>
16 
17 DECLARE_GLOBAL_DATA_PTR;
18 
19 /**
20  * do_aes() - Handle the "aes" command-line command
21  * @cmdtp:	Command data struct pointer
22  * @flag:	Command flag
23  * @argc:	Command-line argument count
24  * @argv:	Array of command-line arguments
25  *
26  * Returns zero on success, CMD_RET_USAGE in case of misuse and negative
27  * on error.
28  */
29 static int do_aes(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[])
30 {
31 	uint32_t key_addr, iv_addr, src_addr, dst_addr, len;
32 	uint8_t *key_ptr, *iv_ptr, *src_ptr, *dst_ptr;
33 	uint8_t key_exp[AES_EXPAND_KEY_LENGTH];
34 	uint32_t aes_blocks;
35 	int enc;
36 
37 	if (argc != 7)
38 		return CMD_RET_USAGE;
39 
40 	if (!strncmp(argv[1], "enc", 3))
41 		enc = 1;
42 	else if (!strncmp(argv[1], "dec", 3))
43 		enc = 0;
44 	else
45 		return CMD_RET_USAGE;
46 
47 	key_addr = simple_strtoul(argv[2], NULL, 16);
48 	iv_addr = simple_strtoul(argv[3], NULL, 16);
49 	src_addr = simple_strtoul(argv[4], NULL, 16);
50 	dst_addr = simple_strtoul(argv[5], NULL, 16);
51 	len = simple_strtoul(argv[6], NULL, 16);
52 
53 	key_ptr = (uint8_t *)key_addr;
54 	iv_ptr = (uint8_t *)iv_addr;
55 	src_ptr = (uint8_t *)src_addr;
56 	dst_ptr = (uint8_t *)dst_addr;
57 
58 	/* First we expand the key. */
59 	aes_expand_key(key_ptr, key_exp);
60 
61 	/* Calculate the number of AES blocks to encrypt. */
62 	aes_blocks = DIV_ROUND_UP(len, AES_KEY_LENGTH);
63 
64 	if (enc)
65 		aes_cbc_encrypt_blocks(key_exp, iv_ptr, src_ptr, dst_ptr,
66 				       aes_blocks);
67 	else
68 		aes_cbc_decrypt_blocks(key_exp, iv_ptr, src_ptr, dst_ptr,
69 				       aes_blocks);
70 
71 	return 0;
72 }
73 
74 /***************************************************/
75 #ifdef CONFIG_SYS_LONGHELP
76 static char aes_help_text[] =
77 	"enc key iv src dst len - Encrypt block of data $len bytes long\n"
78 	"                             at address $src using a key at address\n"
79 	"                             $key with initialization vector at address\n"
80 	"                             $iv. Store the result at address $dst.\n"
81 	"                             The $len size must be multiple of 16 bytes.\n"
82 	"                             The $key and $iv must be 16 bytes long.\n"
83 	"aes dec key iv src dst len - Decrypt block of data $len bytes long\n"
84 	"                             at address $src using a key at address\n"
85 	"                             $key with initialization vector at address\n"
86 	"                             $iv. Store the result at address $dst.\n"
87 	"                             The $len size must be multiple of 16 bytes.\n"
88 	"                             The $key and $iv must be 16 bytes long.";
89 #endif
90 
91 U_BOOT_CMD(
92 	aes, 7, 1, do_aes,
93 	"AES 128 CBC encryption",
94 	aes_help_text
95 );
96