xref: /openbmc/u-boot/cmd/aes.c (revision cbd2fba1)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2014 Marek Vasut <marex@denx.de>
4  *
5  * Command for en/de-crypting block of memory with AES-128-CBC cipher.
6  */
7 
8 #include <common.h>
9 #include <command.h>
10 #include <environment.h>
11 #include <uboot_aes.h>
12 #include <malloc.h>
13 #include <asm/byteorder.h>
14 #include <linux/compiler.h>
15 
16 /**
17  * do_aes() - Handle the "aes" command-line command
18  * @cmdtp:	Command data struct pointer
19  * @flag:	Command flag
20  * @argc:	Command-line argument count
21  * @argv:	Array of command-line arguments
22  *
23  * Returns zero on success, CMD_RET_USAGE in case of misuse and negative
24  * on error.
25  */
26 static int do_aes(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[])
27 {
28 	uint32_t key_addr, iv_addr, src_addr, dst_addr, len;
29 	uint8_t *key_ptr, *iv_ptr, *src_ptr, *dst_ptr;
30 	uint8_t key_exp[AES_EXPAND_KEY_LENGTH];
31 	uint32_t aes_blocks;
32 	int enc;
33 
34 	if (argc != 7)
35 		return CMD_RET_USAGE;
36 
37 	if (!strncmp(argv[1], "enc", 3))
38 		enc = 1;
39 	else if (!strncmp(argv[1], "dec", 3))
40 		enc = 0;
41 	else
42 		return CMD_RET_USAGE;
43 
44 	key_addr = simple_strtoul(argv[2], NULL, 16);
45 	iv_addr = simple_strtoul(argv[3], NULL, 16);
46 	src_addr = simple_strtoul(argv[4], NULL, 16);
47 	dst_addr = simple_strtoul(argv[5], NULL, 16);
48 	len = simple_strtoul(argv[6], NULL, 16);
49 
50 	key_ptr = (uint8_t *)key_addr;
51 	iv_ptr = (uint8_t *)iv_addr;
52 	src_ptr = (uint8_t *)src_addr;
53 	dst_ptr = (uint8_t *)dst_addr;
54 
55 	/* First we expand the key. */
56 	aes_expand_key(key_ptr, key_exp);
57 
58 	/* Calculate the number of AES blocks to encrypt. */
59 	aes_blocks = DIV_ROUND_UP(len, AES_KEY_LENGTH);
60 
61 	if (enc)
62 		aes_cbc_encrypt_blocks(key_exp, iv_ptr, src_ptr, dst_ptr,
63 				       aes_blocks);
64 	else
65 		aes_cbc_decrypt_blocks(key_exp, iv_ptr, src_ptr, dst_ptr,
66 				       aes_blocks);
67 
68 	return 0;
69 }
70 
71 /***************************************************/
72 #ifdef CONFIG_SYS_LONGHELP
73 static char aes_help_text[] =
74 	"enc key iv src dst len - Encrypt block of data $len bytes long\n"
75 	"                             at address $src using a key at address\n"
76 	"                             $key with initialization vector at address\n"
77 	"                             $iv. Store the result at address $dst.\n"
78 	"                             The $len size must be multiple of 16 bytes.\n"
79 	"                             The $key and $iv must be 16 bytes long.\n"
80 	"aes dec key iv src dst len - Decrypt block of data $len bytes long\n"
81 	"                             at address $src using a key at address\n"
82 	"                             $key with initialization vector at address\n"
83 	"                             $iv. Store the result at address $dst.\n"
84 	"                             The $len size must be multiple of 16 bytes.\n"
85 	"                             The $key and $iv must be 16 bytes long.";
86 #endif
87 
88 U_BOOT_CMD(
89 	aes, 7, 1, do_aes,
90 	"AES 128 CBC encryption",
91 	aes_help_text
92 );
93