u-boot/cmd/aes.c
Андрей Мозжухин af09eba64f aes: Allow non-zero initialization vector
AES encryption in CBC mode, in most cases, must be used with random
initialization vector. Using the same key and initialization vector several
times is weak and must be avoided.

Added iv parameter to the aes_cbc_encrypt_blocks and aes_cbc_decrypt_blocks
functions for passing initialization vector.

Command 'aes' now also require the initialization vector parameter.

Signed-off-by: Andrey Mozzhuhin <amozzhuhin@yandex.ru>
2018-01-29 12:50:13 -05:00

95 lines
2.8 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 <uboot_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, iv_addr, src_addr, dst_addr, len;
uint8_t *key_ptr, *iv_ptr, *src_ptr, *dst_ptr;
uint8_t key_exp[AES_EXPAND_KEY_LENGTH];
uint32_t aes_blocks;
int enc;
if (argc != 7)
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);
iv_addr = simple_strtoul(argv[3], NULL, 16);
src_addr = simple_strtoul(argv[4], NULL, 16);
dst_addr = simple_strtoul(argv[5], NULL, 16);
len = simple_strtoul(argv[6], NULL, 16);
key_ptr = (uint8_t *)key_addr;
iv_ptr = (uint8_t *)iv_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, iv_ptr, src_ptr, dst_ptr,
aes_blocks);
else
aes_cbc_decrypt_blocks(key_exp, iv_ptr, src_ptr, dst_ptr,
aes_blocks);
return 0;
}
/***************************************************/
#ifdef CONFIG_SYS_LONGHELP
static char aes_help_text[] =
"enc key iv src dst len - Encrypt block of data $len bytes long\n"
" at address $src using a key at address\n"
" $key with initialization vector at address\n"
" $iv. Store the result at address $dst.\n"
" The $len size must be multiple of 16 bytes.\n"
" The $key and $iv must be 16 bytes long.\n"
"aes dec key iv src dst len - Decrypt block of data $len bytes long\n"
" at address $src using a key at address\n"
" $key with initialization vector at address\n"
" $iv. Store the result at address $dst.\n"
" The $len size must be multiple of 16 bytes.\n"
" The $key and $iv must be 16 bytes long.";
#endif
U_BOOT_CMD(
aes, 7, 1, do_aes,
"AES 128 CBC encryption",
aes_help_text
);