xref: /openbmc/u-boot/cmd/aes.c (revision 35546f6f2014282cc4f9772324b5588bd44a2938)
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 <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, src_addr, dst_addr, len;
32  	uint8_t *key_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 != 6)
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  	src_addr = simple_strtoul(argv[3], NULL, 16);
49  	dst_addr = simple_strtoul(argv[4], NULL, 16);
50  	len = simple_strtoul(argv[5], NULL, 16);
51  
52  	key_ptr = (uint8_t *)key_addr;
53  	src_ptr = (uint8_t *)src_addr;
54  	dst_ptr = (uint8_t *)dst_addr;
55  
56  	/* First we expand the key. */
57  	aes_expand_key(key_ptr, key_exp);
58  
59  	/* Calculate the number of AES blocks to encrypt. */
60  	aes_blocks = DIV_ROUND_UP(len, AES_KEY_LENGTH);
61  
62  	if (enc)
63  		aes_cbc_encrypt_blocks(key_exp, src_ptr, dst_ptr, aes_blocks);
64  	else
65  		aes_cbc_decrypt_blocks(key_exp, src_ptr, dst_ptr, aes_blocks);
66  
67  	return 0;
68  }
69  
70  /***************************************************/
71  #ifdef CONFIG_SYS_LONGHELP
72  static char aes_help_text[] =
73  	"enc key src dst len - Encrypt block of data $len bytes long\n"
74  	"                          at address $src using a key at address\n"
75  	"                          $key and store the result at address\n"
76  	"                          $dst. The $len size must be multiple of\n"
77  	"                          16 bytes and $key must be 16 bytes long.\n"
78  	"aes dec key src dst len - Decrypt block of data $len bytes long\n"
79  	"                          at address $src using a key at address\n"
80  	"                          $key and store the result at address\n"
81  	"                          $dst. The $len size must be multiple of\n"
82  	"                          16 bytes and $key must be 16 bytes long.";
83  #endif
84  
85  U_BOOT_CMD(
86  	aes, 6, 1, do_aes,
87  	"AES 128 CBC encryption",
88  	aes_help_text
89  );
90