Until now, we only support aes128. This commit add the support of aes192 and aes256.
Signed-off-by: Philippe Reynes philippe.reynes@softathome.com --- cmd/aes.c | 38 +++++++++++++++++--------- include/uboot_aes.h | 34 +++++++++++++++-------- lib/aes.c | 77 +++++++++++++++++++++++++++++++++++++---------------- 3 files changed, 103 insertions(+), 46 deletions(-)
diff --git a/cmd/aes.c b/cmd/aes.c index d0a45fa..e0e43cc 100644 --- a/cmd/aes.c +++ b/cmd/aes.c @@ -2,7 +2,7 @@ /* * Copyright (C) 2014 Marek Vasut marex@denx.de * - * Command for en/de-crypting block of memory with AES-128-CBC cipher. + * Command for en/de-crypting block of memory with AES-[128/192/256]-CBC cipher. */
#include <common.h> @@ -13,6 +13,18 @@ #include <linux/compiler.h> #include <mapmem.h>
+u32 aes_get_key_len(char *command) +{ + u32 key_len = AES128_KEY_LENGTH; + + if (!strcmp(command, "aes.192")) + key_len = AES192_KEY_LENGTH; + else if (!strcmp(command, "aes.256")) + key_len = AES256_KEY_LENGTH; + + return key_len; +} + /** * do_aes() - Handle the "aes" command-line command * @cmdtp: Command data struct pointer @@ -27,13 +39,15 @@ 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; + u8 key_exp[AES256_EXPAND_KEY_LENGTH]; + u32 aes_blocks, key_len; int enc;
if (argc != 7) return CMD_RET_USAGE;
+ key_len = aes_get_key_len(argv[0]); + if (!strncmp(argv[1], "enc", 3)) enc = 1; else if (!strncmp(argv[1], "dec", 3)) @@ -47,23 +61,23 @@ static int do_aes(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[]) dst_addr = simple_strtoul(argv[5], NULL, 16); len = simple_strtoul(argv[6], NULL, 16);
- key_ptr = (uint8_t *)map_sysmem(key_addr, 128 / 8); + key_ptr = (uint8_t *)map_sysmem(key_addr, key_len); iv_ptr = (uint8_t *)map_sysmem(iv_addr, 128 / 8); src_ptr = (uint8_t *)map_sysmem(src_addr, len); dst_ptr = (uint8_t *)map_sysmem(dst_addr, len);
/* First we expand the key. */ - aes_expand_key(key_ptr, key_exp); + aes_expand_key(key_ptr, key_len, key_exp);
/* Calculate the number of AES blocks to encrypt. */ aes_blocks = DIV_ROUND_UP(len, AES_BLOCK_LENGTH);
if (enc) - aes_cbc_encrypt_blocks(key_exp, iv_ptr, src_ptr, dst_ptr, - aes_blocks); + aes_cbc_encrypt_blocks(key_len, 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); + aes_cbc_decrypt_blocks(key_len, key_exp, iv_ptr, src_ptr, + dst_ptr, aes_blocks);
return 0; } @@ -71,13 +85,13 @@ static int do_aes(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[]) /***************************************************/ #ifdef CONFIG_SYS_LONGHELP static char aes_help_text[] = - "enc key iv src dst len - Encrypt block of data $len bytes long\n" + "[.128,.192,.256] 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" + "[.128,.192,.256] 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" @@ -87,6 +101,6 @@ static char aes_help_text[] =
U_BOOT_CMD( aes, 7, 1, do_aes, - "AES 128 CBC encryption", + "AES 128/192/256 CBC encryption", aes_help_text ); diff --git a/include/uboot_aes.h b/include/uboot_aes.h index 1ae3ac9..d2583be 100644 --- a/include/uboot_aes.h +++ b/include/uboot_aes.h @@ -23,11 +23,18 @@ typedef unsigned int u32;
enum { AES_STATECOLS = 4, /* columns in the state & expanded key */ - AES_KEYCOLS = 4, /* columns in a key */ - AES_ROUNDS = 10, /* rounds in encryption */ - - AES_KEY_LENGTH = 128 / 8, - AES_EXPAND_KEY_LENGTH = 4 * AES_STATECOLS * (AES_ROUNDS + 1), + AES128_KEYCOLS = 4, /* columns in a key for aes128 */ + AES192_KEYCOLS = 6, /* columns in a key for aes128 */ + AES256_KEYCOLS = 8, /* columns in a key for aes128 */ + AES128_ROUNDS = 10, /* rounds in encryption for aes128 */ + AES192_ROUNDS = 12, /* rounds in encryption for aes192 */ + AES256_ROUNDS = 14, /* rounds in encryption for aes256 */ + AES128_KEY_LENGTH = 128 / 8, + AES192_KEY_LENGTH = 192 / 8, + AES256_KEY_LENGTH = 256 / 8, + AES128_EXPAND_KEY_LENGTH = 4 * AES_STATECOLS * (AES128_ROUNDS + 1), + AES192_EXPAND_KEY_LENGTH = 4 * AES_STATECOLS * (AES192_ROUNDS + 1), + AES256_EXPAND_KEY_LENGTH = 4 * AES_STATECOLS * (AES256_ROUNDS + 1), AES_BLOCK_LENGTH = 128 / 8, };
@@ -37,28 +44,31 @@ enum { * Expand a key into a key schedule, which is then used for the other * operations. * - * @key Key, of length AES_KEY_LENGTH bytes + * @key Key + * @key_size Size of the key (in bits) * @expkey Buffer to place expanded key, AES_EXPAND_KEY_LENGTH */ -void aes_expand_key(u8 *key, u8 *expkey); +void aes_expand_key(u8 *key, u32 key_size, u8 *expkey);
/** * aes_encrypt() - Encrypt single block of data with AES 128 * + * @key_size Size of the aes key (in bits) * @in Input data * @expkey Expanded key to use for encryption (from aes_expand_key()) * @out Output data */ -void aes_encrypt(u8 *in, u8 *expkey, u8 *out); +void aes_encrypt(u32 key_size, u8 *in, u8 *expkey, u8 *out);
/** * aes_decrypt() - Decrypt single block of data with AES 128 * + * @key_size Size of the aes key (in bits) * @in Input data * @expkey Expanded key to use for decryption (from aes_expand_key()) * @out Output data */ -void aes_decrypt(u8 *in, u8 *expkey, u8 *out); +void aes_decrypt(u32 key_size, u8 *in, u8 *expkey, u8 *out);
/** * Apply chain data to the destination using EOR @@ -74,25 +84,27 @@ void aes_apply_cbc_chain_data(u8 *cbc_chain_data, u8 *src, u8 *dst); /** * aes_cbc_encrypt_blocks() - Encrypt multiple blocks of data with AES CBC. * + * @key_size Size of the aes key (in bits) * @key_exp Expanded key to use * @iv Initialization vector * @src Source data to encrypt * @dst Destination buffer * @num_aes_blocks Number of AES blocks to encrypt */ -void aes_cbc_encrypt_blocks(u8 *key_exp, u8 *iv, u8 *src, u8 *dst, +void aes_cbc_encrypt_blocks(u32 key_size, u8 *key_exp, u8 *iv, u8 *src, u8 *dst, u32 num_aes_blocks);
/** * Decrypt multiple blocks of data with AES CBC. * + * @key_size Size of the aes key (in bits) * @key_exp Expanded key to use * @iv Initialization vector * @src Source data to decrypt * @dst Destination buffer * @num_aes_blocks Number of AES blocks to decrypt */ -void aes_cbc_decrypt_blocks(u8 *key_exp, u8 *iv, u8 *src, u8 *dst, +void aes_cbc_decrypt_blocks(u32 key_size, u8 *key_exp, u8 *iv, u8 *src, u8 *dst, u32 num_aes_blocks);
#endif /* _AES_REF_H_ */ diff --git a/lib/aes.c b/lib/aes.c index cfa57b6..ce53c9f 100644 --- a/lib/aes.c +++ b/lib/aes.c @@ -508,50 +508,79 @@ static u8 rcon[11] = { 0x00, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36 };
+static u32 aes_get_rounds(u32 key_len) +{ + u32 rounds = AES128_ROUNDS; + + if (key_len == AES192_KEY_LENGTH) + rounds = AES192_ROUNDS; + else if (key_len == AES256_KEY_LENGTH) + rounds = AES256_ROUNDS; + + return rounds; +} + +static u32 aes_get_keycols(u32 key_len) +{ + u32 keycols = AES128_KEYCOLS; + + if (key_len == AES192_KEY_LENGTH) + keycols = AES192_KEYCOLS; + else if (key_len == AES256_KEY_LENGTH) + keycols = AES256_KEYCOLS; + + return keycols; +} + /* produce AES_STATECOLS bytes for each round */ -void aes_expand_key(u8 *key, u8 *expkey) +void aes_expand_key(u8 *key, u32 key_len, u8 *expkey) { u8 tmp0, tmp1, tmp2, tmp3, tmp4; - u32 idx; + u32 idx, aes_rounds, aes_keycols;
- memcpy(expkey, key, AES_KEYCOLS * 4); + aes_rounds = aes_get_rounds(key_len); + aes_keycols = aes_get_keycols(key_len);
- for (idx = AES_KEYCOLS; idx < AES_STATECOLS * (AES_ROUNDS + 1); idx++) { + memcpy(expkey, key, key_len); + + for (idx = aes_keycols; idx < AES_STATECOLS * (aes_rounds + 1); idx++) { tmp0 = expkey[4*idx - 4]; tmp1 = expkey[4*idx - 3]; tmp2 = expkey[4*idx - 2]; tmp3 = expkey[4*idx - 1]; - if (!(idx % AES_KEYCOLS)) { + if (!(idx % aes_keycols)) { tmp4 = tmp3; tmp3 = sbox[tmp0]; - tmp0 = sbox[tmp1] ^ rcon[idx / AES_KEYCOLS]; + tmp0 = sbox[tmp1] ^ rcon[idx / aes_keycols]; tmp1 = sbox[tmp2]; tmp2 = sbox[tmp4]; - } else if ((AES_KEYCOLS > 6) && (idx % AES_KEYCOLS == 4)) { + } else if ((aes_keycols > 6) && (idx % aes_keycols == 4)) { tmp0 = sbox[tmp0]; tmp1 = sbox[tmp1]; tmp2 = sbox[tmp2]; tmp3 = sbox[tmp3]; }
- expkey[4*idx+0] = expkey[4*idx - 4*AES_KEYCOLS + 0] ^ tmp0; - expkey[4*idx+1] = expkey[4*idx - 4*AES_KEYCOLS + 1] ^ tmp1; - expkey[4*idx+2] = expkey[4*idx - 4*AES_KEYCOLS + 2] ^ tmp2; - expkey[4*idx+3] = expkey[4*idx - 4*AES_KEYCOLS + 3] ^ tmp3; + expkey[4*idx+0] = expkey[4*idx - 4*aes_keycols + 0] ^ tmp0; + expkey[4*idx+1] = expkey[4*idx - 4*aes_keycols + 1] ^ tmp1; + expkey[4*idx+2] = expkey[4*idx - 4*aes_keycols + 2] ^ tmp2; + expkey[4*idx+3] = expkey[4*idx - 4*aes_keycols + 3] ^ tmp3; } }
/* encrypt one 128 bit block */ -void aes_encrypt(u8 *in, u8 *expkey, u8 *out) +void aes_encrypt(u32 key_len, u8 *in, u8 *expkey, u8 *out) { u8 state[AES_STATECOLS * 4]; - u32 round; + u32 round, aes_rounds; + + aes_rounds = aes_get_rounds(key_len);
memcpy(state, in, AES_STATECOLS * 4); add_round_key((u32 *)state, (u32 *)expkey);
- for (round = 1; round < AES_ROUNDS + 1; round++) { - if (round < AES_ROUNDS) + for (round = 1; round < aes_rounds + 1; round++) { + if (round < aes_rounds) mix_sub_columns(state); else shift_rows(state); @@ -563,18 +592,20 @@ void aes_encrypt(u8 *in, u8 *expkey, u8 *out) memcpy(out, state, sizeof(state)); }
-void aes_decrypt(u8 *in, u8 *expkey, u8 *out) +void aes_decrypt(u32 key_len, u8 *in, u8 *expkey, u8 *out) { u8 state[AES_STATECOLS * 4]; - int round; + int round, aes_rounds; + + aes_rounds = aes_get_rounds(key_len);
memcpy(state, in, sizeof(state));
add_round_key((u32 *)state, - (u32 *)expkey + AES_ROUNDS * AES_STATECOLS); + (u32 *)expkey + aes_rounds * AES_STATECOLS); inv_shift_rows(state);
- for (round = AES_ROUNDS; round--; ) { + for (round = aes_rounds; round--; ) { add_round_key((u32 *)state, (u32 *)expkey + round * AES_STATECOLS); if (round) @@ -600,7 +631,7 @@ void aes_apply_cbc_chain_data(u8 *cbc_chain_data, u8 *src, u8 *dst) *dst++ = *src++ ^ *cbc_chain_data++; }
-void aes_cbc_encrypt_blocks(u8 *key_exp, u8 *iv, u8 *src, u8 *dst, +void aes_cbc_encrypt_blocks(u32 key_len, u8 *key_exp, u8 *iv, u8 *src, u8 *dst, u32 num_aes_blocks) { u8 tmp_data[AES_BLOCK_LENGTH]; @@ -616,7 +647,7 @@ void aes_cbc_encrypt_blocks(u8 *key_exp, u8 *iv, u8 *src, u8 *dst, debug_print_vector("AES Xor", AES_BLOCK_LENGTH, tmp_data);
/* Encrypt the AES block */ - aes_encrypt(tmp_data, key_exp, dst); + aes_encrypt(key_len, tmp_data, key_exp, dst); debug_print_vector("AES Dst", AES_BLOCK_LENGTH, dst);
/* Update pointers for next loop. */ @@ -626,7 +657,7 @@ void aes_cbc_encrypt_blocks(u8 *key_exp, u8 *iv, u8 *src, u8 *dst, } }
-void aes_cbc_decrypt_blocks(u8 *key_exp, u8 *iv, u8 *src, u8 *dst, +void aes_cbc_decrypt_blocks(u32 key_len, u8 *key_exp, u8 *iv, u8 *src, u8 *dst, u32 num_aes_blocks) { u8 tmp_data[AES_BLOCK_LENGTH], tmp_block[AES_BLOCK_LENGTH]; @@ -642,7 +673,7 @@ void aes_cbc_decrypt_blocks(u8 *key_exp, u8 *iv, u8 *src, u8 *dst, memcpy(tmp_block, src, AES_BLOCK_LENGTH);
/* Decrypt the AES block */ - aes_decrypt(src, key_exp, tmp_data); + aes_decrypt(key_len, src, key_exp, tmp_data); debug_print_vector("AES Xor", AES_BLOCK_LENGTH, tmp_data);
/* Apply the chain data */