cmd/aes.c

   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 );