u-boot/common/cmd_aes.c
Marek Vasut b401b73d02 aes: Add 'aes' command to access AES-128-CBC
Add simple 'aes' command, which allows using the AES-128-CBC encryption
and decryption functions from U-Boot command line.

Signed-off-by: Marek Vasut <marex@denx.de>
2014-03-21 16:43:58 -04:00

90 lines
2.5 KiB
C

/*
* Copyright (C) 2014 Marek Vasut <marex@denx.de>
*
* Command for en/de-crypting block of memory with AES-128-CBC cipher.
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <command.h>
#include <environment.h>
#include <aes.h>
#include <malloc.h>
#include <asm/byteorder.h>
#include <linux/compiler.h>
DECLARE_GLOBAL_DATA_PTR;
/**
* do_aes() - Handle the "aes" command-line command
* @cmdtp: Command data struct pointer
* @flag: Command flag
* @argc: Command-line argument count
* @argv: Array of command-line arguments
*
* Returns zero on success, CMD_RET_USAGE in case of misuse and negative
* on error.
*/
static int do_aes(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[])
{
uint32_t key_addr, src_addr, dst_addr, len;
uint8_t *key_ptr, *src_ptr, *dst_ptr;
uint8_t key_exp[AES_EXPAND_KEY_LENGTH];
uint32_t aes_blocks;
int enc;
if (argc != 6)
return CMD_RET_USAGE;
if (!strncmp(argv[1], "enc", 3))
enc = 1;
else if (!strncmp(argv[1], "dec", 3))
enc = 0;
else
return CMD_RET_USAGE;
key_addr = simple_strtoul(argv[2], NULL, 16);
src_addr = simple_strtoul(argv[3], NULL, 16);
dst_addr = simple_strtoul(argv[4], NULL, 16);
len = simple_strtoul(argv[5], NULL, 16);
key_ptr = (uint8_t *)key_addr;
src_ptr = (uint8_t *)src_addr;
dst_ptr = (uint8_t *)dst_addr;
/* First we expand the key. */
aes_expand_key(key_ptr, key_exp);
/* Calculate the number of AES blocks to encrypt. */
aes_blocks = DIV_ROUND_UP(len, AES_KEY_LENGTH);
if (enc)
aes_cbc_encrypt_blocks(key_exp, src_ptr, dst_ptr, aes_blocks);
else
aes_cbc_decrypt_blocks(key_exp, src_ptr, dst_ptr, aes_blocks);
return 0;
}
/***************************************************/
#ifdef CONFIG_SYS_LONGHELP
static char aes_help_text[] =
"enc key src dst len - Encrypt block of data $len bytes long\n"
" at address $src using a key at address\n"
" $key and store the result at address\n"
" $dst. The $len size must be multiple of\n"
" 16 bytes and $key must be 16 bytes long.\n"
"aes dec key src dst len - Decrypt block of data $len bytes long\n"
" at address $src using a key at address\n"
" $key and store the result at address\n"
" $dst. The $len size must be multiple of\n"
" 16 bytes and $key must be 16 bytes long.";
#endif
U_BOOT_CMD(
aes, 6, 1, do_aes,
"AES 128 CBC encryption",
aes_help_text
);