LXR uboot/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-[128/192/256]-CBC cipher.
   6 */
   7
   8#include <common.h>
   9#include <command.h>
  10#include <uboot_aes.h>
  11#include <malloc.h>
  12#include <asm/byteorder.h>
  13#include <linux/compiler.h>
  14#include <mapmem.h>
  15
  16u32 aes_get_key_len(char *command)
  17{
  18        u32 key_len = AES128_KEY_LENGTH;
  19
  20        if (!strcmp(command, "aes.192"))
  21                key_len = AES192_KEY_LENGTH;
  22        else if (!strcmp(command, "aes.256"))
  23                key_len = AES256_KEY_LENGTH;
  24
  25        return key_len;
  26}
  27
  28/**
  29 * do_aes() - Handle the "aes" command-line command
  30 * @cmdtp:      Command data struct pointer
  31 * @flag:       Command flag
  32 * @argc:       Command-line argument count
  33 * @argv:       Array of command-line arguments
  34 *
  35 * Returns zero on success, CMD_RET_USAGE in case of misuse and negative
  36 * on error.
  37 */
  38static int do_aes(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
  39{
  40        uint32_t key_addr, iv_addr, src_addr, dst_addr, len;
  41        uint8_t *key_ptr, *iv_ptr, *src_ptr, *dst_ptr;
  42        u8 key_exp[AES256_EXPAND_KEY_LENGTH];
  43        u32 aes_blocks, key_len;
  44        int enc;
  45
  46        if (argc != 7)
  47                return CMD_RET_USAGE;
  48
  49        key_len = aes_get_key_len(argv[0]);
  50
  51        if (!strncmp(argv[1], "enc", 3))
  52                enc = 1;
  53        else if (!strncmp(argv[1], "dec", 3))
  54                enc = 0;
  55        else
  56                return CMD_RET_USAGE;
  57
  58        key_addr = hextoul(argv[2], NULL);
  59        iv_addr = hextoul(argv[3], NULL);
  60        src_addr = hextoul(argv[4], NULL);
  61        dst_addr = hextoul(argv[5], NULL);
  62        len = hextoul(argv[6], NULL);
  63
  64        key_ptr = (uint8_t *)map_sysmem(key_addr, key_len);
  65        iv_ptr = (uint8_t *)map_sysmem(iv_addr, 128 / 8);
  66        src_ptr = (uint8_t *)map_sysmem(src_addr, len);
  67        dst_ptr = (uint8_t *)map_sysmem(dst_addr, len);
  68
  69        /* First we expand the key. */
  70        aes_expand_key(key_ptr, key_len, key_exp);
  71
  72        /* Calculate the number of AES blocks to encrypt. */
  73        aes_blocks = DIV_ROUND_UP(len, AES_BLOCK_LENGTH);
  74
  75        if (enc)
  76                aes_cbc_encrypt_blocks(key_len, key_exp, iv_ptr, src_ptr,
  77                                       dst_ptr, aes_blocks);
  78        else
  79                aes_cbc_decrypt_blocks(key_len, key_exp, iv_ptr, src_ptr,
  80                                       dst_ptr, aes_blocks);
  81
  82        unmap_sysmem(key_ptr);
  83        unmap_sysmem(iv_ptr);
  84        unmap_sysmem(src_ptr);
  85        unmap_sysmem(dst_ptr);
  86
  87        return 0;
  88}
  89
  90/***************************************************/
  91#ifdef CONFIG_SYS_LONGHELP
  92static char aes_help_text[] =
  93        "[.128,.192,.256] enc key iv src dst len - Encrypt block of data $len bytes long\n"
  94        "                             at address $src using a key at address\n"
  95        "                             $key with initialization vector at address\n"
  96        "                             $iv. Store the result at address $dst.\n"
  97        "                             The $len size must be multiple of 16 bytes.\n"
  98        "                             The $key and $iv must be 16 bytes long.\n"
  99        "aes [.128,.192,.256] dec key iv src dst len - Decrypt block of data $len bytes long\n"
 100        "                             at address $src using a key at address\n"
 101        "                             $key with initialization vector at address\n"
 102        "                             $iv. Store the result at address $dst.\n"
 103        "                             The $len size must be multiple of 16 bytes.\n"
 104        "                             The $key and $iv must be 16 bytes long.";
 105#endif
 106
 107U_BOOT_CMD(
 108        aes, 7, 1, do_aes,
 109        "AES 128/192/256 CBC encryption",
 110        aes_help_text
 111);
 112