library/aes.c

/*
 *  FIPS-197 compliant AES implementation
 *
 *  Copyright The Mbed TLS Contributors
 *  SPDX-License-Identifier: Apache-2.0
 *
 *  Licensed under the Apache License, Version 2.0 (the "License"); you may
 *  not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */
/*
 *  The AES block cipher was designed by Vincent Rijmen and Joan Daemen.
 *
 *  https://csrc.nist.gov/csrc/media/projects/cryptographic-standards-and-guidelines/documents/aes-development/rijndael-ammended.pdf
 *  http://csrc.nist.gov/publications/fips/fips197/fips-197.pdf
 */

#include "common.h"

#if defined(MBEDTLS_AES_C)

#include <string.h>

#include "mbedtls/aes.h"
#include "mbedtls/platform.h"
#include "mbedtls/platform_util.h"
#include "mbedtls/error.h"

#if defined(MBEDTLS_AES_USE_HARDWARE_ONLY)
#if !((defined(MBEDTLS_ARCH_IS_ARM64) && defined(MBEDTLS_AESCE_C)) || \
    (defined(MBEDTLS_ARCH_IS_X64)   && defined(MBEDTLS_AESNI_C)) || \
    (defined(MBEDTLS_ARCH_IS_X86)   && defined(MBEDTLS_AESNI_C)))
#error "MBEDTLS_AES_USE_HARDWARE_ONLY defined, but not all prerequisites"
#endif
#endif

#if defined(MBEDTLS_ARCH_IS_X86)
#if defined(MBEDTLS_PADLOCK_C)
#if !defined(MBEDTLS_HAVE_ASM)
#error "MBEDTLS_PADLOCK_C defined, but not all prerequisites"
#endif
#if defined(MBEDTLS_AES_USE_HARDWARE_ONLY)
#error "MBEDTLS_AES_USE_HARDWARE_ONLY cannot be defined when " \
    "MBEDTLS_PADLOCK_C is set"
#endif
#endif
#endif

#if defined(MBEDTLS_PADLOCK_C)
#include "padlock.h"
#endif
#if defined(MBEDTLS_AESNI_C)
#include "aesni.h"
#endif
#if defined(MBEDTLS_AESCE_C)
#include "aesce.h"
#endif

#include "mbedtls/platform.h"

#if !defined(MBEDTLS_AES_ALT)

#if defined(MBEDTLS_VIA_PADLOCK_HAVE_CODE)
static int aes_padlock_ace = -1;
#endif

#if defined(MBEDTLS_AES_ROM_TABLES)
/*
 * Forward S-box
 */
#if !defined(MBEDTLS_AES_ENCRYPT_ALT) || !defined(MBEDTLS_AES_SETKEY_ENC_ALT) || \
    !defined(MBEDTLS_AES_SETKEY_DEC_ALT)
static const unsigned char FSb[256] =
{
    0x63, 0x7C, 0x77, 0x7B, 0xF2, 0x6B, 0x6F, 0xC5,
    0x30, 0x01, 0x67, 0x2B, 0xFE, 0xD7, 0xAB, 0x76,
    0xCA, 0x82, 0xC9, 0x7D, 0xFA, 0x59, 0x47, 0xF0,
    0xAD, 0xD4, 0xA2, 0xAF, 0x9C, 0xA4, 0x72, 0xC0,
    0xB7, 0xFD, 0x93, 0x26, 0x36, 0x3F, 0xF7, 0xCC,
    0x34, 0xA5, 0xE5, 0xF1, 0x71, 0xD8, 0x31, 0x15,
    0x04, 0xC7, 0x23, 0xC3, 0x18, 0x96, 0x05, 0x9A,
    0x07, 0x12, 0x80, 0xE2, 0xEB, 0x27, 0xB2, 0x75,
    0x09, 0x83, 0x2C, 0x1A, 0x1B, 0x6E, 0x5A, 0xA0,
    0x52, 0x3B, 0xD6, 0xB3, 0x29, 0xE3, 0x2F, 0x84,
    0x53, 0xD1, 0x00, 0xED, 0x20, 0xFC, 0xB1, 0x5B,
    0x6A, 0xCB, 0xBE, 0x39, 0x4A, 0x4C, 0x58, 0xCF,
    0xD0, 0xEF, 0xAA, 0xFB, 0x43, 0x4D, 0x33, 0x85,
    0x45, 0xF9, 0x02, 0x7F, 0x50, 0x3C, 0x9F, 0xA8,
    0x51, 0xA3, 0x40, 0x8F, 0x92, 0x9D, 0x38, 0xF5,
    0xBC, 0xB6, 0xDA, 0x21, 0x10, 0xFF, 0xF3, 0xD2,
    0xCD, 0x0C, 0x13, 0xEC, 0x5F, 0x97, 0x44, 0x17,
    0xC4, 0xA7, 0x7E, 0x3D, 0x64, 0x5D, 0x19, 0x73,
    0x60, 0x81, 0x4F, 0xDC, 0x22, 0x2A, 0x90, 0x88,
    0x46, 0xEE, 0xB8, 0x14, 0xDE, 0x5E, 0x0B, 0xDB,
    0xE0, 0x32, 0x3A, 0x0A, 0x49, 0x06, 0x24, 0x5C,
    0xC2, 0xD3, 0xAC, 0x62, 0x91, 0x95, 0xE4, 0x79,
    0xE7, 0xC8, 0x37, 0x6D, 0x8D, 0xD5, 0x4E, 0xA9,
    0x6C, 0x56, 0xF4, 0xEA, 0x65, 0x7A, 0xAE, 0x08,
    0xBA, 0x78, 0x25, 0x2E, 0x1C, 0xA6, 0xB4, 0xC6,
    0xE8, 0xDD, 0x74, 0x1F, 0x4B, 0xBD, 0x8B, 0x8A,
    0x70, 0x3E, 0xB5, 0x66, 0x48, 0x03, 0xF6, 0x0E,
    0x61, 0x35, 0x57, 0xB9, 0x86, 0xC1, 0x1D, 0x9E,
    0xE1, 0xF8, 0x98, 0x11, 0x69, 0xD9, 0x8E, 0x94,
    0x9B, 0x1E, 0x87, 0xE9, 0xCE, 0x55, 0x28, 0xDF,
    0x8C, 0xA1, 0x89, 0x0D, 0xBF, 0xE6, 0x42, 0x68,
    0x41, 0x99, 0x2D, 0x0F, 0xB0, 0x54, 0xBB, 0x16
};
#endif /* !defined(MBEDTLS_AES_ENCRYPT_ALT) || !defined(MBEDTLS_AES_SETKEY_ENC_ALT) || \
          !defined(MBEDTLS_AES_SETKEY_DEC_ALT) */

/*
 * Forward tables
 */
#define FT \
\
    V(A5, 63, 63, C6), V(84, 7C, 7C, F8), V(99, 77, 77, EE), V(8D, 7B, 7B, F6), \
    V(0D, F2, F2, FF), V(BD, 6B, 6B, D6), V(B1, 6F, 6F, DE), V(54, C5, C5, 91), \
    V(50, 30, 30, 60), V(03, 01, 01, 02), V(A9, 67, 67, CE), V(7D, 2B, 2B, 56), \
    V(19, FE, FE, E7), V(62, D7, D7, B5), V(E6, AB, AB, 4D), V(9A, 76, 76, EC), \
    V(45, CA, CA, 8F), V(9D, 82, 82, 1F), V(40, C9, C9, 89), V(87, 7D, 7D, FA), \
    V(15, FA, FA, EF), V(EB, 59, 59, B2), V(C9, 47, 47, 8E), V(0B, F0, F0, FB), \
    V(EC, AD, AD, 41), V(67, D4, D4, B3), V(FD, A2, A2, 5F), V(EA, AF, AF, 45), \
    V(BF, 9C, 9C, 23), V(F7, A4, A4, 53), V(96, 72, 72, E4), V(5B, C0, C0, 9B), \
    V(C2, B7, B7, 75), V(1C, FD, FD, E1), V(AE, 93, 93, 3D), V(6A, 26, 26, 4C), \
    V(5A, 36, 36, 6C), V(41, 3F, 3F, 7E), V(02, F7, F7, F5), V(4F, CC, CC, 83), \
    V(5C, 34, 34, 68), V(F4, A5, A5, 51), V(34, E5, E5, D1), V(08, F1, F1, F9), \
    V(93, 71, 71, E2), V(73, D8, D8, AB), V(53, 31, 31, 62), V(3F, 15, 15, 2A), \
    V(0C, 04, 04, 08), V(52, C7, C7, 95), V(65, 23, 23, 46), V(5E, C3, C3, 9D), \
    V(28, 18, 18, 30), V(A1, 96, 96, 37), V(0F, 05, 05, 0A), V(B5, 9A, 9A, 2F), \
    V(09, 07, 07, 0E), V(36, 12, 12, 24), V(9B, 80, 80, 1B), V(3D, E2, E2, DF), \
    V(26, EB, EB, CD), V(69, 27, 27, 4E), V(CD, B2, B2, 7F), V(9F, 75, 75, EA), \
    V(1B, 09, 09, 12), V(9E, 83, 83, 1D), V(74, 2C, 2C, 58), V(2E, 1A, 1A, 34), \
    V(2D, 1B, 1B, 36), V(B2, 6E, 6E, DC), V(EE, 5A, 5A, B4), V(FB, A0, A0, 5B), \
    V(F6, 52, 52, A4), V(4D, 3B, 3B, 76), V(61, D6, D6, B7), V(CE, B3, B3, 7D), \
    V(7B, 29, 29, 52), V(3E, E3, E3, DD), V(71, 2F, 2F, 5E), V(97, 84, 84, 13), \
    V(F5, 53, 53, A6), V(68, D1, D1, B9), V(00, 00, 00, 00), V(2C, ED, ED, C1), \
    V(60, 20, 20, 40), V(1F, FC, FC, E3), V(C8, B1, B1, 79), V(ED, 5B, 5B, B6), \
    V(BE, 6A, 6A, D4), V(46, CB, CB, 8D), V(D9, BE, BE, 67), V(4B, 39, 39, 72), \
    V(DE, 4A, 4A, 94), V(D4, 4C, 4C, 98), V(E8, 58, 58, B0), V(4A, CF, CF, 85), \
    V(6B, D0, D0, BB), V(2A, EF, EF, C5), V(E5, AA, AA, 4F), V(16, FB, FB, ED), \
    V(C5, 43, 43, 86), V(D7, 4D, 4D, 9A), V(55, 33, 33, 66), V(94, 85, 85, 11), \
    V(CF, 45, 45, 8A), V(10, F9, F9, E9), V(06, 02, 02, 04), V(81, 7F, 7F, FE), \
    V(F0, 50, 50, A0), V(44, 3C, 3C, 78), V(BA, 9F, 9F, 25), V(E3, A8, A8, 4B), \
    V(F3, 51, 51, A2), V(FE, A3, A3, 5D), V(C0, 40, 40, 80), V(8A, 8F, 8F, 05), \
    V(AD, 92, 92, 3F), V(BC, 9D, 9D, 21), V(48, 38, 38, 70), V(04, F5, F5, F1), \
    V(DF, BC, BC, 63), V(C1, B6, B6, 77), V(75, DA, DA, AF), V(63, 21, 21, 42), \
    V(30, 10, 10, 20), V(1A, FF, FF, E5), V(0E, F3, F3, FD), V(6D, D2, D2, BF), \
    V(4C, CD, CD, 81), V(14, 0C, 0C, 18), V(35, 13, 13, 26), V(2F, EC, EC, C3), \
    V(E1, 5F, 5F, BE), V(A2, 97, 97, 35), V(CC, 44, 44, 88), V(39, 17, 17, 2E), \
    V(57, C4, C4, 93), V(F2, A7, A7, 55), V(82, 7E, 7E, FC), V(47, 3D, 3D, 7A), \
    V(AC, 64, 64, C8), V(E7, 5D, 5D, BA), V(2B, 19, 19, 32), V(95, 73, 73, E6), \
    V(A0, 60, 60, C0), V(98, 81, 81, 19), V(D1, 4F, 4F, 9E), V(7F, DC, DC, A3), \
    V(66, 22, 22, 44), V(7E, 2A, 2A, 54), V(AB, 90, 90, 3B), V(83, 88, 88, 0B), \
    V(CA, 46, 46, 8C), V(29, EE, EE, C7), V(D3, B8, B8, 6B), V(3C, 14, 14, 28), \
    V(79, DE, DE, A7), V(E2, 5E, 5E, BC), V(1D, 0B, 0B, 16), V(76, DB, DB, AD), \
    V(3B, E0, E0, DB), V(56, 32, 32, 64), V(4E, 3A, 3A, 74), V(1E, 0A, 0A, 14), \
    V(DB, 49, 49, 92), V(0A, 06, 06, 0C), V(6C, 24, 24, 48), V(E4, 5C, 5C, B8), \
    V(5D, C2, C2, 9F), V(6E, D3, D3, BD), V(EF, AC, AC, 43), V(A6, 62, 62, C4), \
    V(A8, 91, 91, 39), V(A4, 95, 95, 31), V(37, E4, E4, D3), V(8B, 79, 79, F2), \
    V(32, E7, E7, D5), V(43, C8, C8, 8B), V(59, 37, 37, 6E), V(B7, 6D, 6D, DA), \
    V(8C, 8D, 8D, 01), V(64, D5, D5, B1), V(D2, 4E, 4E, 9C), V(E0, A9, A9, 49), \
    V(B4, 6C, 6C, D8), V(FA, 56, 56, AC), V(07, F4, F4, F3), V(25, EA, EA, CF), \
    V(AF, 65, 65, CA), V(8E, 7A, 7A, F4), V(E9, AE, AE, 47), V(18, 08, 08, 10), \
    V(D5, BA, BA, 6F), V(88, 78, 78, F0), V(6F, 25, 25, 4A), V(72, 2E, 2E, 5C), \
    V(24, 1C, 1C, 38), V(F1, A6, A6, 57), V(C7, B4, B4, 73), V(51, C6, C6, 97), \
    V(23, E8, E8, CB), V(7C, DD, DD, A1), V(9C, 74, 74, E8), V(21, 1F, 1F, 3E), \
    V(DD, 4B, 4B, 96), V(DC, BD, BD, 61), V(86, 8B, 8B, 0D), V(85, 8A, 8A, 0F), \
    V(90, 70, 70, E0), V(42, 3E, 3E, 7C), V(C4, B5, B5, 71), V(AA, 66, 66, CC), \
    V(D8, 48, 48, 90), V(05, 03, 03, 06), V(01, F6, F6, F7), V(12, 0E, 0E, 1C), \
    V(A3, 61, 61, C2), V(5F, 35, 35, 6A), V(F9, 57, 57, AE), V(D0, B9, B9, 69), \
    V(91, 86, 86, 17), V(58, C1, C1, 99), V(27, 1D, 1D, 3A), V(B9, 9E, 9E, 27), \
    V(38, E1, E1, D9), V(13, F8, F8, EB), V(B3, 98, 98, 2B), V(33, 11, 11, 22), \
    V(BB, 69, 69, D2), V(70, D9, D9, A9), V(89, 8E, 8E, 07), V(A7, 94, 94, 33), \
    V(B6, 9B, 9B, 2D), V(22, 1E, 1E, 3C), V(92, 87, 87, 15), V(20, E9, E9, C9), \
    V(49, CE, CE, 87), V(FF, 55, 55, AA), V(78, 28, 28, 50), V(7A, DF, DF, A5), \
    V(8F, 8C, 8C, 03), V(F8, A1, A1, 59), V(80, 89, 89, 09), V(17, 0D, 0D, 1A), \
    V(DA, BF, BF, 65), V(31, E6, E6, D7), V(C6, 42, 42, 84), V(B8, 68, 68, D0), \
    V(C3, 41, 41, 82), V(B0, 99, 99, 29), V(77, 2D, 2D, 5A), V(11, 0F, 0F, 1E), \
    V(CB, B0, B0, 7B), V(FC, 54, 54, A8), V(D6, BB, BB, 6D), V(3A, 16, 16, 2C)

#if !defined(MBEDTLS_AES_ENCRYPT_ALT)
#define V(a, b, c, d) 0x##a##b##c##d
static const uint32_t FT0[256] = { FT };
#undef V

#if !defined(MBEDTLS_AES_FEWER_TABLES)

#define V(a, b, c, d) 0x##b##c##d##a
static const uint32_t FT1[256] = { FT };
#undef V

#define V(a, b, c, d) 0x##c##d##a##b
static const uint32_t FT2[256] = { FT };
#undef V

#define V(a, b, c, d) 0x##d##a##b##c
static const uint32_t FT3[256] = { FT };
#undef V

#endif /* !MBEDTLS_AES_FEWER_TABLES */

#endif /* !defined(MBEDTLS_AES_ENCRYPT_ALT) */

#undef FT

#if !defined(MBEDTLS_AES_DECRYPT_ALT)
/*
 * Reverse S-box
 */
static const unsigned char RSb[256] =
{
    0x52, 0x09, 0x6A, 0xD5, 0x30, 0x36, 0xA5, 0x38,
    0xBF, 0x40, 0xA3, 0x9E, 0x81, 0xF3, 0xD7, 0xFB,
    0x7C, 0xE3, 0x39, 0x82, 0x9B, 0x2F, 0xFF, 0x87,
    0x34, 0x8E, 0x43, 0x44, 0xC4, 0xDE, 0xE9, 0xCB,
    0x54, 0x7B, 0x94, 0x32, 0xA6, 0xC2, 0x23, 0x3D,
    0xEE, 0x4C, 0x95, 0x0B, 0x42, 0xFA, 0xC3, 0x4E,
    0x08, 0x2E, 0xA1, 0x66, 0x28, 0xD9, 0x24, 0xB2,
    0x76, 0x5B, 0xA2, 0x49, 0x6D, 0x8B, 0xD1, 0x25,
    0x72, 0xF8, 0xF6, 0x64, 0x86, 0x68, 0x98, 0x16,
    0xD4, 0xA4, 0x5C, 0xCC, 0x5D, 0x65, 0xB6, 0x92,
    0x6C, 0x70, 0x48, 0x50, 0xFD, 0xED, 0xB9, 0xDA,
    0x5E, 0x15, 0x46, 0x57, 0xA7, 0x8D, 0x9D, 0x84,
    0x90, 0xD8, 0xAB, 0x00, 0x8C, 0xBC, 0xD3, 0x0A,
    0xF7, 0xE4, 0x58, 0x05, 0xB8, 0xB3, 0x45, 0x06,
    0xD0, 0x2C, 0x1E, 0x8F, 0xCA, 0x3F, 0x0F, 0x02,
    0xC1, 0xAF, 0xBD, 0x03, 0x01, 0x13, 0x8A, 0x6B,
    0x3A, 0x91, 0x11, 0x41, 0x4F, 0x67, 0xDC, 0xEA,
    0x97, 0xF2, 0xCF, 0xCE, 0xF0, 0xB4, 0xE6, 0x73,
    0x96, 0xAC, 0x74, 0x22, 0xE7, 0xAD, 0x35, 0x85,
    0xE2, 0xF9, 0x37, 0xE8, 0x1C, 0x75, 0xDF, 0x6E,
    0x47, 0xF1, 0x1A, 0x71, 0x1D, 0x29, 0xC5, 0x89,
    0x6F, 0xB7, 0x62, 0x0E, 0xAA, 0x18, 0xBE, 0x1B,
    0xFC, 0x56, 0x3E, 0x4B, 0xC6, 0xD2, 0x79, 0x20,
    0x9A, 0xDB, 0xC0, 0xFE, 0x78, 0xCD, 0x5A, 0xF4,
    0x1F, 0xDD, 0xA8, 0x33, 0x88, 0x07, 0xC7, 0x31,
    0xB1, 0x12, 0x10, 0x59, 0x27, 0x80, 0xEC, 0x5F,
    0x60, 0x51, 0x7F, 0xA9, 0x19, 0xB5, 0x4A, 0x0D,
    0x2D, 0xE5, 0x7A, 0x9F, 0x93, 0xC9, 0x9C, 0xEF,
    0xA0, 0xE0, 0x3B, 0x4D, 0xAE, 0x2A, 0xF5, 0xB0,
    0xC8, 0xEB, 0xBB, 0x3C, 0x83, 0x53, 0x99, 0x61,
    0x17, 0x2B, 0x04, 0x7E, 0xBA, 0x77, 0xD6, 0x26,
    0xE1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0C, 0x7D
};
#endif /* defined(MBEDTLS_AES_DECRYPT_ALT)) */

/*
 * Reverse tables
 */
#define RT \
\
    V(50, A7, F4, 51), V(53, 65, 41, 7E), V(C3, A4, 17, 1A), V(96, 5E, 27, 3A), \
    V(CB, 6B, AB, 3B), V(F1, 45, 9D, 1F), V(AB, 58, FA, AC), V(93, 03, E3, 4B), \
    V(55, FA, 30, 20), V(F6, 6D, 76, AD), V(91, 76, CC, 88), V(25, 4C, 02, F5), \
    V(FC, D7, E5, 4F), V(D7, CB, 2A, C5), V(80, 44, 35, 26), V(8F, A3, 62, B5), \
    V(49, 5A, B1, DE), V(67, 1B, BA, 25), V(98, 0E, EA, 45), V(E1, C0, FE, 5D), \
    V(02, 75, 2F, C3), V(12, F0, 4C, 81), V(A3, 97, 46, 8D), V(C6, F9, D3, 6B), \
    V(E7, 5F, 8F, 03), V(95, 9C, 92, 15), V(EB, 7A, 6D, BF), V(DA, 59, 52, 95), \
    V(2D, 83, BE, D4), V(D3, 21, 74, 58), V(29, 69, E0, 49), V(44, C8, C9, 8E), \
    V(6A, 89, C2, 75), V(78, 79, 8E, F4), V(6B, 3E, 58, 99), V(DD, 71, B9, 27), \
    V(B6, 4F, E1, BE), V(17, AD, 88, F0), V(66, AC, 20, C9), V(B4, 3A, CE, 7D), \
    V(18, 4A, DF, 63), V(82, 31, 1A, E5), V(60, 33, 51, 97), V(45, 7F, 53, 62), \
    V(E0, 77, 64, B1), V(84, AE, 6B, BB), V(1C, A0, 81, FE), V(94, 2B, 08, F9), \
    V(58, 68, 48, 70), V(19, FD, 45, 8F), V(87, 6C, DE, 94), V(B7, F8, 7B, 52), \
    V(23, D3, 73, AB), V(E2, 02, 4B, 72), V(57, 8F, 1F, E3), V(2A, AB, 55, 66), \
    V(07, 28, EB, B2), V(03, C2, B5, 2F), V(9A, 7B, C5, 86), V(A5, 08, 37, D3), \
    V(F2, 87, 28, 30), V(B2, A5, BF, 23), V(BA, 6A, 03, 02), V(5C, 82, 16, ED), \
    V(2B, 1C, CF, 8A), V(92, B4, 79, A7), V(F0, F2, 07, F3), V(A1, E2, 69, 4E), \
    V(CD, F4, DA, 65), V(D5, BE, 05, 06), V(1F, 62, 34, D1), V(8A, FE, A6, C4), \
    V(9D, 53, 2E, 34), V(A0, 55, F3, A2), V(32, E1, 8A, 05), V(75, EB, F6, A4), \
    V(39, EC, 83, 0B), V(AA, EF, 60, 40), V(06, 9F, 71, 5E), V(51, 10, 6E, BD), \
    V(F9, 8A, 21, 3E), V(3D, 06, DD, 96), V(AE, 05, 3E, DD), V(46, BD, E6, 4D), \
    V(B5, 8D, 54, 91), V(05, 5D, C4, 71), V(6F, D4, 06, 04), V(FF, 15, 50, 60), \
    V(24, FB, 98, 19), V(97, E9, BD, D6), V(CC, 43, 40, 89), V(77, 9E, D9, 67), \
    V(BD, 42, E8, B0), V(88, 8B, 89, 07), V(38, 5B, 19, E7), V(DB, EE, C8, 79), \
    V(47, 0A, 7C, A1), V(E9, 0F, 42, 7C), V(C9, 1E, 84, F8), V(00, 00, 00, 00), \
    V(83, 86, 80, 09), V(48, ED, 2B, 32), V(AC, 70, 11, 1E), V(4E, 72, 5A, 6C), \
    V(FB, FF, 0E, FD), V(56, 38, 85, 0F), V(1E, D5, AE, 3D), V(27, 39, 2D, 36), \
    V(64, D9, 0F, 0A), V(21, A6, 5C, 68), V(D1, 54, 5B, 9B), V(3A, 2E, 36, 24), \
    V(B1, 67, 0A, 0C), V(0F, E7, 57, 93), V(D2, 96, EE, B4), V(9E, 91, 9B, 1B), \
    V(4F, C5, C0, 80), V(A2, 20, DC, 61), V(69, 4B, 77, 5A), V(16, 1A, 12, 1C), \
    V(0A, BA, 93, E2), V(E5, 2A, A0, C0), V(43, E0, 22, 3C), V(1D, 17, 1B, 12), \
    V(0B, 0D, 09, 0E), V(AD, C7, 8B, F2), V(B9, A8, B6, 2D), V(C8, A9, 1E, 14), \
    V(85, 19, F1, 57), V(4C, 07, 75, AF), V(BB, DD, 99, EE), V(FD, 60, 7F, A3), \
    V(9F, 26, 01, F7), V(BC, F5, 72, 5C), V(C5, 3B, 66, 44), V(34, 7E, FB, 5B), \
    V(76, 29, 43, 8B), V(DC, C6, 23, CB), V(68, FC, ED, B6), V(63, F1, E4, B8), \
    V(CA, DC, 31, D7), V(10, 85, 63, 42), V(40, 22, 97, 13), V(20, 11, C6, 84), \
    V(7D, 24, 4A, 85), V(F8, 3D, BB, D2), V(11, 32, F9, AE), V(6D, A1, 29, C7), \
    V(4B, 2F, 9E, 1D), V(F3, 30, B2, DC), V(EC, 52, 86, 0D), V(D0, E3, C1, 77), \
    V(6C, 16, B3, 2B), V(99, B9, 70, A9), V(FA, 48, 94, 11), V(22, 64, E9, 47), \
    V(C4, 8C, FC, A8), V(1A, 3F, F0, A0), V(D8, 2C, 7D, 56), V(EF, 90, 33, 22), \
    V(C7, 4E, 49, 87), V(C1, D1, 38, D9), V(FE, A2, CA, 8C), V(36, 0B, D4, 98), \
    V(CF, 81, F5, A6), V(28, DE, 7A, A5), V(26, 8E, B7, DA), V(A4, BF, AD, 3F), \
    V(E4, 9D, 3A, 2C), V(0D, 92, 78, 50), V(9B, CC, 5F, 6A), V(62, 46, 7E, 54), \
    V(C2, 13, 8D, F6), V(E8, B8, D8, 90), V(5E, F7, 39, 2E), V(F5, AF, C3, 82), \
    V(BE, 80, 5D, 9F), V(7C, 93, D0, 69), V(A9, 2D, D5, 6F), V(B3, 12, 25, CF), \
    V(3B, 99, AC, C8), V(A7, 7D, 18, 10), V(6E, 63, 9C, E8), V(7B, BB, 3B, DB), \
    V(09, 78, 26, CD), V(F4, 18, 59, 6E), V(01, B7, 9A, EC), V(A8, 9A, 4F, 83), \
    V(65, 6E, 95, E6), V(7E, E6, FF, AA), V(08, CF, BC, 21), V(E6, E8, 15, EF), \
    V(D9, 9B, E7, BA), V(CE, 36, 6F, 4A), V(D4, 09, 9F, EA), V(D6, 7C, B0, 29), \
    V(AF, B2, A4, 31), V(31, 23, 3F, 2A), V(30, 94, A5, C6), V(C0, 66, A2, 35), \
    V(37, BC, 4E, 74), V(A6, CA, 82, FC), V(B0, D0, 90, E0), V(15, D8, A7, 33), \
    V(4A, 98, 04, F1), V(F7, DA, EC, 41), V(0E, 50, CD, 7F), V(2F, F6, 91, 17), \
    V(8D, D6, 4D, 76), V(4D, B0, EF, 43), V(54, 4D, AA, CC), V(DF, 04, 96, E4), \
    V(E3, B5, D1, 9E), V(1B, 88, 6A, 4C), V(B8, 1F, 2C, C1), V(7F, 51, 65, 46), \
    V(04, EA, 5E, 9D), V(5D, 35, 8C, 01), V(73, 74, 87, FA), V(2E, 41, 0B, FB), \
    V(5A, 1D, 67, B3), V(52, D2, DB, 92), V(33, 56, 10, E9), V(13, 47, D6, 6D), \
    V(8C, 61, D7, 9A), V(7A, 0C, A1, 37), V(8E, 14, F8, 59), V(89, 3C, 13, EB), \
    V(EE, 27, A9, CE), V(35, C9, 61, B7), V(ED, E5, 1C, E1), V(3C, B1, 47, 7A), \
    V(59, DF, D2, 9C), V(3F, 73, F2, 55), V(79, CE, 14, 18), V(BF, 37, C7, 73), \
    V(EA, CD, F7, 53), V(5B, AA, FD, 5F), V(14, 6F, 3D, DF), V(86, DB, 44, 78), \
    V(81, F3, AF, CA), V(3E, C4, 68, B9), V(2C, 34, 24, 38), V(5F, 40, A3, C2), \
    V(72, C3, 1D, 16), V(0C, 25, E2, BC), V(8B, 49, 3C, 28), V(41, 95, 0D, FF), \
    V(71, 01, A8, 39), V(DE, B3, 0C, 08), V(9C, E4, B4, D8), V(90, C1, 56, 64), \
    V(61, 84, CB, 7B), V(70, B6, 32, D5), V(74, 5C, 6C, 48), V(42, 57, B8, D0)

#if !defined(MBEDTLS_AES_DECRYPT_ALT) || !defined(MBEDTLS_AES_SETKEY_DEC_ALT)

#define V(a, b, c, d) 0x##a##b##c##d
static const uint32_t RT0[256] = { RT };
#undef V

#if !defined(MBEDTLS_AES_FEWER_TABLES)

#define V(a, b, c, d) 0x##b##c##d##a
static const uint32_t RT1[256] = { RT };
#undef V

#define V(a, b, c, d) 0x##c##d##a##b
static const uint32_t RT2[256] = { RT };
#undef V

#define V(a, b, c, d) 0x##d##a##b##c
static const uint32_t RT3[256] = { RT };
#undef V

#endif /* !MBEDTLS_AES_FEWER_TABLES */

#endif /* !defined(MBEDTLS_AES_DECRYPT_ALT) || !defined(MBEDTLS_AES_SETKEY_DEC_ALT) */

#undef RT

#if !defined(MBEDTLS_AES_SETKEY_ENC_ALT)
/*
 * Round constants
 */
static const uint32_t round_constants[10] =
{
    0x00000001, 0x00000002, 0x00000004, 0x00000008,
    0x00000010, 0x00000020, 0x00000040, 0x00000080,
    0x0000001B, 0x00000036
};
#endif /* !defined(MBEDTLS_AES_SETKEY_ENC_ALT) */

#else /* MBEDTLS_AES_ROM_TABLES */

/*
 * Forward S-box & tables
 */
#if !defined(MBEDTLS_AES_ENCRYPT_ALT) || !defined(MBEDTLS_AES_SETKEY_ENC_ALT) || \
    !defined(MBEDTLS_AES_SETKEY_DEC_ALT)
static unsigned char FSb[256];
#endif /* !defined(MBEDTLS_AES_ENCRYPT_ALT) || !defined(MBEDTLS_AES_SETKEY_ENC_ALT) || \
          !defined(MBEDTLS_AES_SETKEY_DEC_ALT) */
#if !defined(MBEDTLS_AES_ENCRYPT_ALT) || !defined(MBEDTLS_AES_SETKEY_ENC_ALT)
static uint32_t FT0[256];
#if !defined(MBEDTLS_AES_FEWER_TABLES)
static uint32_t FT1[256];
static uint32_t FT2[256];
static uint32_t FT3[256];
#endif /* !MBEDTLS_AES_FEWER_TABLES */
#endif /* !defined(MBEDTLS_AES_ENCRYPT_ALT) || !defined(MBEDTLS_AES_SETKEY_ENC_ALT) */

/*
 * Reverse S-box & tables
 */
#if !(defined(MBEDTLS_AES_SETKEY_ENC_ALT) && defined(MBEDTLS_AES_DECRYPT_ALT))
static unsigned char RSb[256];
#endif /* !(defined(MBEDTLS_AES_SETKEY_ENC_ALT) && defined(MBEDTLS_AES_DECRYPT_ALT)) */

#if !defined(MBEDTLS_AES_DECRYPT_ALT) || !defined(MBEDTLS_AES_SETKEY_DEC_ALT)
static uint32_t RT0[256];
#if !defined(MBEDTLS_AES_FEWER_TABLES)
static uint32_t RT1[256];
static uint32_t RT2[256];
static uint32_t RT3[256];
#endif /* !MBEDTLS_AES_FEWER_TABLES */
#endif /* !defined(MBEDTLS_AES_DECRYPT_ALT) || !defined(MBEDTLS_AES_SETKEY_DEC_ALT) */

#if !defined(MBEDTLS_AES_SETKEY_ENC_ALT)
/*
 * Round constants
 */
static uint32_t round_constants[10];

/*
 * Tables generation code
 */
#define ROTL8(x) (((x) << 8) & 0xFFFFFFFF) | ((x) >> 24)
#define XTIME(x) (((x) << 1) ^ (((x) & 0x80) ? 0x1B : 0x00))
#define MUL(x, y) (((x) && (y)) ? pow[(log[(x)]+log[(y)]) % 255] : 0)

static int aes_init_done = 0;

static void aes_gen_tables(void)
{
    int i;
    uint8_t x, y, z;
    uint8_t pow[256];
    uint8_t log[256];

    /*
     * compute pow and log tables over GF(2^8)
     */
    for (i = 0, x = 1; i < 256; i++) {
        pow[i] = x;
        log[x] = (uint8_t) i;
        x ^= XTIME(x);
    }

    /*
     * calculate the round constants
     */
    for (i = 0, x = 1; i < 10; i++) {
        round_constants[i] = x;
        x = XTIME(x);
    }

    /*
     * generate the forward and reverse S-boxes
     */
    FSb[0x00] = 0x63;
    RSb[0x63] = 0x00;

    for (i = 1; i < 256; i++) {
        x = pow[255 - log[i]];

        y  = x; y = (y << 1) | (y >> 7);
        x ^= y; y = (y << 1) | (y >> 7);
        x ^= y; y = (y << 1) | (y >> 7);
        x ^= y; y = (y << 1) | (y >> 7);
        x ^= y ^ 0x63;

        FSb[i] = x;
        RSb[x] = (unsigned char) i;
    }

    /*
     * generate the forward and reverse tables
     */
    for (i = 0; i < 256; i++) {
        x = FSb[i];
        y = XTIME(x);
        z = y ^ x;

        FT0[i] = ((uint32_t) y) ^
                 ((uint32_t) x <<  8) ^
                 ((uint32_t) x << 16) ^
                 ((uint32_t) z << 24);

#if !defined(MBEDTLS_AES_FEWER_TABLES)
        FT1[i] = ROTL8(FT0[i]);
        FT2[i] = ROTL8(FT1[i]);
        FT3[i] = ROTL8(FT2[i]);
#endif /* !MBEDTLS_AES_FEWER_TABLES */

        x = RSb[i];

#if !defined(MBEDTLS_AES_DECRYPT_ALT) || !defined(MBEDTLS_AES_SETKEY_DEC_ALT)
        RT0[i] = ((uint32_t) MUL(0x0E, x)) ^
                 ((uint32_t) MUL(0x09, x) <<  8) ^
                 ((uint32_t) MUL(0x0D, x) << 16) ^
                 ((uint32_t) MUL(0x0B, x) << 24);

#if !defined(MBEDTLS_AES_FEWER_TABLES)
        RT1[i] = ROTL8(RT0[i]);
        RT2[i] = ROTL8(RT1[i]);
        RT3[i] = ROTL8(RT2[i]);
#endif /* !MBEDTLS_AES_FEWER_TABLES */
#endif /* !defined(MBEDTLS_AES_DECRYPT_ALT) || !defined(MBEDTLS_AES_SETKEY_DEC_ALT) */
    }
}

#endif /* !defined(MBEDTLS_AES_SETKEY_ENC_ALT) */

#undef ROTL8

#endif /* MBEDTLS_AES_ROM_TABLES */

#if defined(MBEDTLS_AES_FEWER_TABLES)

#define ROTL8(x)  ((uint32_t) ((x) <<  8) + (uint32_t) ((x) >> 24))
#define ROTL16(x) ((uint32_t) ((x) << 16) + (uint32_t) ((x) >> 16))
#define ROTL24(x) ((uint32_t) ((x) << 24) + (uint32_t) ((x) >>  8))

#define AES_RT0(idx) RT0[idx]
#define AES_RT1(idx) ROTL8(RT0[idx])
#define AES_RT2(idx) ROTL16(RT0[idx])
#define AES_RT3(idx) ROTL24(RT0[idx])

#define AES_FT0(idx) FT0[idx]
#define AES_FT1(idx) ROTL8(FT0[idx])
#define AES_FT2(idx) ROTL16(FT0[idx])
#define AES_FT3(idx) ROTL24(FT0[idx])

#else /* MBEDTLS_AES_FEWER_TABLES */

#define AES_RT0(idx) RT0[idx]
#define AES_RT1(idx) RT1[idx]
#define AES_RT2(idx) RT2[idx]
#define AES_RT3(idx) RT3[idx]

#define AES_FT0(idx) FT0[idx]
#define AES_FT1(idx) FT1[idx]
#define AES_FT2(idx) FT2[idx]
#define AES_FT3(idx) FT3[idx]

#endif /* MBEDTLS_AES_FEWER_TABLES */

void mbedtls_aes_init(mbedtls_aes_context *ctx)
{
    memset(ctx, 0, sizeof(mbedtls_aes_context));
}

void mbedtls_aes_free(mbedtls_aes_context *ctx)
{
    if (ctx == NULL) {
        return;
    }

    mbedtls_platform_zeroize(ctx, sizeof(mbedtls_aes_context));
}

#if defined(MBEDTLS_CIPHER_MODE_XTS)
void mbedtls_aes_xts_init(mbedtls_aes_xts_context *ctx)
{
    mbedtls_aes_init(&ctx->crypt);
    mbedtls_aes_init(&ctx->tweak);
}

void mbedtls_aes_xts_free(mbedtls_aes_xts_context *ctx)
{
    if (ctx == NULL) {
        return;
    }

    mbedtls_aes_free(&ctx->crypt);
    mbedtls_aes_free(&ctx->tweak);
}
#endif /* MBEDTLS_CIPHER_MODE_XTS */

/* Some implementations need the round keys to be aligned.
 * Return an offset to be added to buf, such that (buf + offset) is
 * correctly aligned.
 * Note that the offset is in units of elements of buf, i.e. 32-bit words,
 * i.e. an offset of 1 means 4 bytes and so on.
 */
#if (defined(MBEDTLS_VIA_PADLOCK_HAVE_CODE)) ||        \
    (defined(MBEDTLS_AESNI_C) && MBEDTLS_AESNI_HAVE_CODE == 2)
#define MAY_NEED_TO_ALIGN
#endif

#if defined(MAY_NEED_TO_ALIGN) || !defined(MBEDTLS_AES_SETKEY_DEC_ALT) || \
    !defined(MBEDTLS_AES_SETKEY_ENC_ALT)
static unsigned mbedtls_aes_rk_offset(uint32_t *buf)
{
#if defined(MAY_NEED_TO_ALIGN)
    int align_16_bytes = 0;

#if defined(MBEDTLS_VIA_PADLOCK_HAVE_CODE)
    if (aes_padlock_ace == -1) {
        aes_padlock_ace = mbedtls_padlock_has_support(MBEDTLS_PADLOCK_ACE);
    }
    if (aes_padlock_ace) {
        align_16_bytes = 1;
    }
#endif

#if defined(MBEDTLS_AESNI_C) && MBEDTLS_AESNI_HAVE_CODE == 2
    if (mbedtls_aesni_has_support(MBEDTLS_AESNI_AES)) {
        align_16_bytes = 1;
    }
#endif

    if (align_16_bytes) {
        /* These implementations needs 16-byte alignment
         * for the round key array. */
        unsigned delta = ((uintptr_t) buf & 0x0000000fU) / 4;
        if (delta == 0) {
            return 0;
        } else {
            return 4 - delta; // 16 bytes = 4 uint32_t
        }
    }
#else /* MAY_NEED_TO_ALIGN */
    (void) buf;
#endif /* MAY_NEED_TO_ALIGN */

    return 0;
}
#endif /* defined(MAY_NEED_TO_ALIGN) || !defined(MBEDTLS_AES_SETKEY_DEC_ALT) || \
          !defined(MBEDTLS_AES_SETKEY_ENC_ALT) */

/*
 * AES key schedule (encryption)
 */
#if !defined(MBEDTLS_AES_SETKEY_ENC_ALT)
int mbedtls_aes_setkey_enc(mbedtls_aes_context *ctx, const unsigned char *key,
                           unsigned int keybits)
{
    uint32_t *RK;

    switch (keybits) {
        case 128: ctx->nr = 10; break;
#if !defined(MBEDTLS_AES_ONLY_128_BIT_KEY_LENGTH)
        case 192: ctx->nr = 12; break;
        case 256: ctx->nr = 14; break;
#endif /* !MBEDTLS_AES_ONLY_128_BIT_KEY_LENGTH */
        default: return MBEDTLS_ERR_AES_INVALID_KEY_LENGTH;
    }

#if !defined(MBEDTLS_AES_ROM_TABLES)
    if (aes_init_done == 0) {
        aes_gen_tables();
        aes_init_done = 1;
    }
#endif

    ctx->rk_offset = mbedtls_aes_rk_offset(ctx->buf);
    RK = ctx->buf + ctx->rk_offset;

#if defined(MBEDTLS_AESNI_HAVE_CODE)
    if (mbedtls_aesni_has_support(MBEDTLS_AESNI_AES)) {
        return mbedtls_aesni_setkey_enc((unsigned char *) RK, key, keybits);
    }
#endif

#if defined(MBEDTLS_AESCE_HAVE_CODE)
    if (MBEDTLS_AESCE_HAS_SUPPORT()) {
        return mbedtls_aesce_setkey_enc((unsigned char *) RK, key, keybits);
    }
#endif

#if !defined(MBEDTLS_AES_USE_HARDWARE_ONLY)
    for (unsigned int i = 0; i < (keybits >> 5); i++) {
        RK[i] = MBEDTLS_GET_UINT32_LE(key, i << 2);
    }

    switch (ctx->nr) {
        case 10:

            for (unsigned int i = 0; i < 10; i++, RK += 4) {
                RK[4]  = RK[0] ^ round_constants[i] ^
                         ((uint32_t) FSb[MBEDTLS_BYTE_1(RK[3])]) ^
                         ((uint32_t) FSb[MBEDTLS_BYTE_2(RK[3])] <<  8) ^
                         ((uint32_t) FSb[MBEDTLS_BYTE_3(RK[3])] << 16) ^
                         ((uint32_t) FSb[MBEDTLS_BYTE_0(RK[3])] << 24);

                RK[5]  = RK[1] ^ RK[4];
                RK[6]  = RK[2] ^ RK[5];
                RK[7]  = RK[3] ^ RK[6];
            }
            break;

#if !defined(MBEDTLS_AES_ONLY_128_BIT_KEY_LENGTH)
        case 12:

            for (unsigned int i = 0; i < 8; i++, RK += 6) {
                RK[6]  = RK[0] ^ round_constants[i] ^
                         ((uint32_t) FSb[MBEDTLS_BYTE_1(RK[5])]) ^
                         ((uint32_t) FSb[MBEDTLS_BYTE_2(RK[5])] <<  8) ^
                         ((uint32_t) FSb[MBEDTLS_BYTE_3(RK[5])] << 16) ^
                         ((uint32_t) FSb[MBEDTLS_BYTE_0(RK[5])] << 24);

                RK[7]  = RK[1] ^ RK[6];
                RK[8]  = RK[2] ^ RK[7];
                RK[9]  = RK[3] ^ RK[8];
                RK[10] = RK[4] ^ RK[9];
                RK[11] = RK[5] ^ RK[10];
            }
            break;

        case 14:

            for (unsigned int i = 0; i < 7; i++, RK += 8) {
                RK[8]  = RK[0] ^ round_constants[i] ^
                         ((uint32_t) FSb[MBEDTLS_BYTE_1(RK[7])]) ^
                         ((uint32_t) FSb[MBEDTLS_BYTE_2(RK[7])] <<  8) ^
                         ((uint32_t) FSb[MBEDTLS_BYTE_3(RK[7])] << 16) ^
                         ((uint32_t) FSb[MBEDTLS_BYTE_0(RK[7])] << 24);

                RK[9]  = RK[1] ^ RK[8];
                RK[10] = RK[2] ^ RK[9];
                RK[11] = RK[3] ^ RK[10];

                RK[12] = RK[4] ^
                         ((uint32_t) FSb[MBEDTLS_BYTE_0(RK[11])]) ^
                         ((uint32_t) FSb[MBEDTLS_BYTE_1(RK[11])] <<  8) ^
                         ((uint32_t) FSb[MBEDTLS_BYTE_2(RK[11])] << 16) ^
                         ((uint32_t) FSb[MBEDTLS_BYTE_3(RK[11])] << 24);

                RK[13] = RK[5] ^ RK[12];
                RK[14] = RK[6] ^ RK[13];
                RK[15] = RK[7] ^ RK[14];
            }
            break;
#endif /* !MBEDTLS_AES_ONLY_128_BIT_KEY_LENGTH */
    }

    return 0;
#endif /* !MBEDTLS_AES_USE_HARDWARE_ONLY */
}
#endif /* !MBEDTLS_AES_SETKEY_ENC_ALT */

/*
 * AES key schedule (decryption)
 */
#if !defined(MBEDTLS_AES_SETKEY_DEC_ALT)
int mbedtls_aes_setkey_dec(mbedtls_aes_context *ctx, const unsigned char *key,
                           unsigned int keybits)
{
#if !defined(MBEDTLS_AES_USE_HARDWARE_ONLY)
    uint32_t *SK;
#endif
    int ret;
    mbedtls_aes_context cty;
    uint32_t *RK;


    mbedtls_aes_init(&cty);

    ctx->rk_offset = mbedtls_aes_rk_offset(ctx->buf);
    RK = ctx->buf + ctx->rk_offset;

    /* Also checks keybits */
    if ((ret = mbedtls_aes_setkey_enc(&cty, key, keybits)) != 0) {
        goto exit;
    }

    ctx->nr = cty.nr;

#if defined(MBEDTLS_AESNI_HAVE_CODE)
    if (mbedtls_aesni_has_support(MBEDTLS_AESNI_AES)) {
        mbedtls_aesni_inverse_key((unsigned char *) RK,
                                  (const unsigned char *) (cty.buf + cty.rk_offset), ctx->nr);
        goto exit;
    }
#endif

#if defined(MBEDTLS_AESCE_HAVE_CODE)
    if (MBEDTLS_AESCE_HAS_SUPPORT()) {
        mbedtls_aesce_inverse_key(
            (unsigned char *) RK,
            (const unsigned char *) (cty.buf + cty.rk_offset),
            ctx->nr);
        goto exit;
    }
#endif

#if !defined(MBEDTLS_AES_USE_HARDWARE_ONLY)
    SK = cty.buf + cty.rk_offset + cty.nr * 4;

    *RK++ = *SK++;
    *RK++ = *SK++;
    *RK++ = *SK++;
    *RK++ = *SK++;
    SK -= 8;
    for (int i = ctx->nr - 1; i > 0; i--, SK -= 8) {
        for (int j = 0; j < 4; j++, SK++) {
            *RK++ = AES_RT0(FSb[MBEDTLS_BYTE_0(*SK)]) ^
                    AES_RT1(FSb[MBEDTLS_BYTE_1(*SK)]) ^
                    AES_RT2(FSb[MBEDTLS_BYTE_2(*SK)]) ^
                    AES_RT3(FSb[MBEDTLS_BYTE_3(*SK)]);
        }
    }

    *RK++ = *SK++;
    *RK++ = *SK++;
    *RK++ = *SK++;
    *RK++ = *SK++;
#endif /* !MBEDTLS_AES_USE_HARDWARE_ONLY */
exit:
    mbedtls_aes_free(&cty);

    return ret;
}
#endif /* !MBEDTLS_AES_SETKEY_DEC_ALT */

#if defined(MBEDTLS_CIPHER_MODE_XTS)
static int mbedtls_aes_xts_decode_keys(const unsigned char *key,
                                       unsigned int keybits,
                                       const unsigned char **key1,
                                       unsigned int *key1bits,
                                       const unsigned char **key2,
                                       unsigned int *key2bits)
{
    const unsigned int half_keybits = keybits / 2;
    const unsigned int half_keybytes = half_keybits / 8;

    switch (keybits) {
        case 256: break;
        case 512: break;
        default: return MBEDTLS_ERR_AES_INVALID_KEY_LENGTH;
    }

    *key1bits = half_keybits;
    *key2bits = half_keybits;
    *key1 = &key[0];
    *key2 = &key[half_keybytes];

    return 0;
}

int mbedtls_aes_xts_setkey_enc(mbedtls_aes_xts_context *ctx,
                               const unsigned char *key,
                               unsigned int keybits)
{
    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
    const unsigned char *key1, *key2;
    unsigned int key1bits, key2bits;

    ret = mbedtls_aes_xts_decode_keys(key, keybits, &key1, &key1bits,
                                      &key2, &key2bits);
    if (ret != 0) {
        return ret;
    }

    /* Set the tweak key. Always set tweak key for the encryption mode. */
    ret = mbedtls_aes_setkey_enc(&ctx->tweak, key2, key2bits);
    if (ret != 0) {
        return ret;
    }

    /* Set crypt key for encryption. */
    return mbedtls_aes_setkey_enc(&ctx->crypt, key1, key1bits);
}

int mbedtls_aes_xts_setkey_dec(mbedtls_aes_xts_context *ctx,
                               const unsigned char *key,
                               unsigned int keybits)
{
    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
    const unsigned char *key1, *key2;
    unsigned int key1bits, key2bits;

    ret = mbedtls_aes_xts_decode_keys(key, keybits, &key1, &key1bits,
                                      &key2, &key2bits);
    if (ret != 0) {
        return ret;
    }

    /* Set the tweak key. Always set tweak key for encryption. */
    ret = mbedtls_aes_setkey_enc(&ctx->tweak, key2, key2bits);
    if (ret != 0) {
        return ret;
    }

    /* Set crypt key for decryption. */
    return mbedtls_aes_setkey_dec(&ctx->crypt, key1, key1bits);
}
#endif /* MBEDTLS_CIPHER_MODE_XTS */

#define AES_FROUND(X0, X1, X2, X3, Y0, Y1, Y2, Y3)                 \
    do                                                      \
    {                                                       \
        (X0) = *RK++ ^ AES_FT0(MBEDTLS_BYTE_0(Y0)) ^    \
               AES_FT1(MBEDTLS_BYTE_1(Y1)) ^    \
               AES_FT2(MBEDTLS_BYTE_2(Y2)) ^    \
               AES_FT3(MBEDTLS_BYTE_3(Y3));     \
                                                            \
        (X1) = *RK++ ^ AES_FT0(MBEDTLS_BYTE_0(Y1)) ^    \
               AES_FT1(MBEDTLS_BYTE_1(Y2)) ^    \
               AES_FT2(MBEDTLS_BYTE_2(Y3)) ^    \
               AES_FT3(MBEDTLS_BYTE_3(Y0));     \
                                                            \
        (X2) = *RK++ ^ AES_FT0(MBEDTLS_BYTE_0(Y2)) ^    \
               AES_FT1(MBEDTLS_BYTE_1(Y3)) ^    \
               AES_FT2(MBEDTLS_BYTE_2(Y0)) ^    \
               AES_FT3(MBEDTLS_BYTE_3(Y1));     \
                                                            \
        (X3) = *RK++ ^ AES_FT0(MBEDTLS_BYTE_0(Y3)) ^    \
               AES_FT1(MBEDTLS_BYTE_1(Y0)) ^    \
               AES_FT2(MBEDTLS_BYTE_2(Y1)) ^    \
               AES_FT3(MBEDTLS_BYTE_3(Y2));     \
    } while (0)

#define AES_RROUND(X0, X1, X2, X3, Y0, Y1, Y2, Y3)                 \
    do                                                      \
    {                                                       \
        (X0) = *RK++ ^ AES_RT0(MBEDTLS_BYTE_0(Y0)) ^    \
               AES_RT1(MBEDTLS_BYTE_1(Y3)) ^    \
               AES_RT2(MBEDTLS_BYTE_2(Y2)) ^    \
               AES_RT3(MBEDTLS_BYTE_3(Y1));     \
                                                            \
        (X1) = *RK++ ^ AES_RT0(MBEDTLS_BYTE_0(Y1)) ^    \
               AES_RT1(MBEDTLS_BYTE_1(Y0)) ^    \
               AES_RT2(MBEDTLS_BYTE_2(Y3)) ^    \
               AES_RT3(MBEDTLS_BYTE_3(Y2));     \
                                                            \
        (X2) = *RK++ ^ AES_RT0(MBEDTLS_BYTE_0(Y2)) ^    \
               AES_RT1(MBEDTLS_BYTE_1(Y1)) ^    \
               AES_RT2(MBEDTLS_BYTE_2(Y0)) ^    \
               AES_RT3(MBEDTLS_BYTE_3(Y3));     \
                                                            \
        (X3) = *RK++ ^ AES_RT0(MBEDTLS_BYTE_0(Y3)) ^    \
               AES_RT1(MBEDTLS_BYTE_1(Y2)) ^    \
               AES_RT2(MBEDTLS_BYTE_2(Y1)) ^    \
               AES_RT3(MBEDTLS_BYTE_3(Y0));     \
    } while (0)

/*
 * AES-ECB block encryption
 */
#if !defined(MBEDTLS_AES_ENCRYPT_ALT)
int mbedtls_internal_aes_encrypt(mbedtls_aes_context *ctx,
                                 const unsigned char input[16],
                                 unsigned char output[16])
{
    int i;
    uint32_t *RK = ctx->buf + ctx->rk_offset;
    struct {
        uint32_t X[4];
        uint32_t Y[4];
    } t;

    t.X[0] = MBEDTLS_GET_UINT32_LE(input,  0); t.X[0] ^= *RK++;
    t.X[1] = MBEDTLS_GET_UINT32_LE(input,  4); t.X[1] ^= *RK++;
    t.X[2] = MBEDTLS_GET_UINT32_LE(input,  8); t.X[2] ^= *RK++;
    t.X[3] = MBEDTLS_GET_UINT32_LE(input, 12); t.X[3] ^= *RK++;

    for (i = (ctx->nr >> 1) - 1; i > 0; i--) {
        AES_FROUND(t.Y[0], t.Y[1], t.Y[2], t.Y[3], t.X[0], t.X[1], t.X[2], t.X[3]);
        AES_FROUND(t.X[0], t.X[1], t.X[2], t.X[3], t.Y[0], t.Y[1], t.Y[2], t.Y[3]);
    }

    AES_FROUND(t.Y[0], t.Y[1], t.Y[2], t.Y[3], t.X[0], t.X[1], t.X[2], t.X[3]);

    t.X[0] = *RK++ ^ \
             ((uint32_t) FSb[MBEDTLS_BYTE_0(t.Y[0])]) ^
             ((uint32_t) FSb[MBEDTLS_BYTE_1(t.Y[1])] <<  8) ^
             ((uint32_t) FSb[MBEDTLS_BYTE_2(t.Y[2])] << 16) ^
             ((uint32_t) FSb[MBEDTLS_BYTE_3(t.Y[3])] << 24);

    t.X[1] = *RK++ ^ \
             ((uint32_t) FSb[MBEDTLS_BYTE_0(t.Y[1])]) ^
             ((uint32_t) FSb[MBEDTLS_BYTE_1(t.Y[2])] <<  8) ^
             ((uint32_t) FSb[MBEDTLS_BYTE_2(t.Y[3])] << 16) ^
             ((uint32_t) FSb[MBEDTLS_BYTE_3(t.Y[0])] << 24);

    t.X[2] = *RK++ ^ \
             ((uint32_t) FSb[MBEDTLS_BYTE_0(t.Y[2])]) ^
             ((uint32_t) FSb[MBEDTLS_BYTE_1(t.Y[3])] <<  8) ^
             ((uint32_t) FSb[MBEDTLS_BYTE_2(t.Y[0])] << 16) ^
             ((uint32_t) FSb[MBEDTLS_BYTE_3(t.Y[1])] << 24);

    t.X[3] = *RK++ ^ \
             ((uint32_t) FSb[MBEDTLS_BYTE_0(t.Y[3])]) ^
             ((uint32_t) FSb[MBEDTLS_BYTE_1(t.Y[0])] <<  8) ^
             ((uint32_t) FSb[MBEDTLS_BYTE_2(t.Y[1])] << 16) ^
             ((uint32_t) FSb[MBEDTLS_BYTE_3(t.Y[2])] << 24);

    MBEDTLS_PUT_UINT32_LE(t.X[0], output,  0);
    MBEDTLS_PUT_UINT32_LE(t.X[1], output,  4);
    MBEDTLS_PUT_UINT32_LE(t.X[2], output,  8);
    MBEDTLS_PUT_UINT32_LE(t.X[3], output, 12);

    mbedtls_platform_zeroize(&t, sizeof(t));

    return 0;
}
#endif /* !MBEDTLS_AES_ENCRYPT_ALT */

/*
 * AES-ECB block decryption
 */
#if !defined(MBEDTLS_AES_DECRYPT_ALT)
int mbedtls_internal_aes_decrypt(mbedtls_aes_context *ctx,
                                 const unsigned char input[16],
                                 unsigned char output[16])
{
    int i;
    uint32_t *RK = ctx->buf + ctx->rk_offset;
    struct {
        uint32_t X[4];
        uint32_t Y[4];
    } t;

    t.X[0] = MBEDTLS_GET_UINT32_LE(input,  0); t.X[0] ^= *RK++;
    t.X[1] = MBEDTLS_GET_UINT32_LE(input,  4); t.X[1] ^= *RK++;
    t.X[2] = MBEDTLS_GET_UINT32_LE(input,  8); t.X[2] ^= *RK++;
    t.X[3] = MBEDTLS_GET_UINT32_LE(input, 12); t.X[3] ^= *RK++;

    for (i = (ctx->nr >> 1) - 1; i > 0; i--) {
        AES_RROUND(t.Y[0], t.Y[1], t.Y[2], t.Y[3], t.X[0], t.X[1], t.X[2], t.X[3]);
        AES_RROUND(t.X[0], t.X[1], t.X[2], t.X[3], t.Y[0], t.Y[1], t.Y[2], t.Y[3]);
    }

    AES_RROUND(t.Y[0], t.Y[1], t.Y[2], t.Y[3], t.X[0], t.X[1], t.X[2], t.X[3]);

    t.X[0] = *RK++ ^ \
             ((uint32_t) RSb[MBEDTLS_BYTE_0(t.Y[0])]) ^
             ((uint32_t) RSb[MBEDTLS_BYTE_1(t.Y[3])] <<  8) ^
             ((uint32_t) RSb[MBEDTLS_BYTE_2(t.Y[2])] << 16) ^
             ((uint32_t) RSb[MBEDTLS_BYTE_3(t.Y[1])] << 24);

    t.X[1] = *RK++ ^ \
             ((uint32_t) RSb[MBEDTLS_BYTE_0(t.Y[1])]) ^
             ((uint32_t) RSb[MBEDTLS_BYTE_1(t.Y[0])] <<  8) ^
             ((uint32_t) RSb[MBEDTLS_BYTE_2(t.Y[3])] << 16) ^
             ((uint32_t) RSb[MBEDTLS_BYTE_3(t.Y[2])] << 24);

    t.X[2] = *RK++ ^ \
             ((uint32_t) RSb[MBEDTLS_BYTE_0(t.Y[2])]) ^
             ((uint32_t) RSb[MBEDTLS_BYTE_1(t.Y[1])] <<  8) ^
             ((uint32_t) RSb[MBEDTLS_BYTE_2(t.Y[0])] << 16) ^
             ((uint32_t) RSb[MBEDTLS_BYTE_3(t.Y[3])] << 24);

    t.X[3] = *RK++ ^ \
             ((uint32_t) RSb[MBEDTLS_BYTE_0(t.Y[3])]) ^
             ((uint32_t) RSb[MBEDTLS_BYTE_1(t.Y[2])] <<  8) ^
             ((uint32_t) RSb[MBEDTLS_BYTE_2(t.Y[1])] << 16) ^
             ((uint32_t) RSb[MBEDTLS_BYTE_3(t.Y[0])] << 24);

    MBEDTLS_PUT_UINT32_LE(t.X[0], output,  0);
    MBEDTLS_PUT_UINT32_LE(t.X[1], output,  4);
    MBEDTLS_PUT_UINT32_LE(t.X[2], output,  8);
    MBEDTLS_PUT_UINT32_LE(t.X[3], output, 12);

    mbedtls_platform_zeroize(&t, sizeof(t));

    return 0;
}
#endif /* !MBEDTLS_AES_DECRYPT_ALT */

#if defined(MAY_NEED_TO_ALIGN)
/* VIA Padlock and our intrinsics-based implementation of AESNI require
 * the round keys to be aligned on a 16-byte boundary. We take care of this
 * before creating them, but the AES context may have moved (this can happen
 * if the library is called from a language with managed memory), and in later
 * calls it might have a different alignment with respect to 16-byte memory.
 * So we may need to realign.
 */
static void aes_maybe_realign(mbedtls_aes_context *ctx)
{
    unsigned new_offset = mbedtls_aes_rk_offset(ctx->buf);
    if (new_offset != ctx->rk_offset) {
        memmove(ctx->buf + new_offset,     // new address
                ctx->buf + ctx->rk_offset, // current address
                (ctx->nr + 1) * 16);       // number of round keys * bytes per rk
        ctx->rk_offset = new_offset;
    }
}
#endif

/*
 * AES-ECB block encryption/decryption
 */
int mbedtls_aes_crypt_ecb(mbedtls_aes_context *ctx,
                          int mode,
                          const unsigned char input[16],
                          unsigned char output[16])
{
    if (mode != MBEDTLS_AES_ENCRYPT && mode != MBEDTLS_AES_DECRYPT) {
        return MBEDTLS_ERR_AES_BAD_INPUT_DATA;
    }

#if defined(MAY_NEED_TO_ALIGN)
    aes_maybe_realign(ctx);
#endif

#if defined(MBEDTLS_AESNI_HAVE_CODE)
    if (mbedtls_aesni_has_support(MBEDTLS_AESNI_AES)) {
        return mbedtls_aesni_crypt_ecb(ctx, mode, input, output);
    }
#endif

#if defined(MBEDTLS_AESCE_HAVE_CODE)
    if (MBEDTLS_AESCE_HAS_SUPPORT()) {
        return mbedtls_aesce_crypt_ecb(ctx, mode, input, output);
    }
#endif

#if defined(MBEDTLS_VIA_PADLOCK_HAVE_CODE)
    if (aes_padlock_ace > 0) {
        return mbedtls_padlock_xcryptecb(ctx, mode, input, output);
    }
#endif

#if !defined(MBEDTLS_AES_USE_HARDWARE_ONLY)
    if (mode == MBEDTLS_AES_ENCRYPT) {
        return mbedtls_internal_aes_encrypt(ctx, input, output);
    } else {
        return mbedtls_internal_aes_decrypt(ctx, input, output);
    }
#endif

}

#if defined(MBEDTLS_CIPHER_MODE_CBC)

/*
 * AES-CBC buffer encryption/decryption
 */
int mbedtls_aes_crypt_cbc(mbedtls_aes_context *ctx,
                          int mode,
                          size_t length,
                          unsigned char iv[16],
                          const unsigned char *input,
                          unsigned char *output)
{
    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
    unsigned char temp[16];

    if (mode != MBEDTLS_AES_ENCRYPT && mode != MBEDTLS_AES_DECRYPT) {
        return MBEDTLS_ERR_AES_BAD_INPUT_DATA;
    }

    /* Nothing to do if length is zero. */
    if (length == 0) {
        return 0;
    }

    if (length % 16) {
        return MBEDTLS_ERR_AES_INVALID_INPUT_LENGTH;
    }

#if defined(MBEDTLS_VIA_PADLOCK_HAVE_CODE)
    if (aes_padlock_ace > 0) {
        if (mbedtls_padlock_xcryptcbc(ctx, mode, length, iv, input, output) == 0) {
            return 0;
        }

        // If padlock data misaligned, we just fall back to
        // unaccelerated mode
        //
    }
#endif

    const unsigned char *ivp = iv;

    if (mode == MBEDTLS_AES_DECRYPT) {
        while (length > 0) {
            memcpy(temp, input, 16);
            ret = mbedtls_aes_crypt_ecb(ctx, mode, input, output);
            if (ret != 0) {
                goto exit;
            }
            /* Avoid using the NEON implementation of mbedtls_xor. Because of the dependency on
             * the result for the next block in CBC, and the cost of transferring that data from
             * NEON registers, NEON is slower on aarch64. */
            mbedtls_xor_no_simd(output, output, iv, 16);

            memcpy(iv, temp, 16);

            input  += 16;
            output += 16;
            length -= 16;
        }
    } else {
        while (length > 0) {
            mbedtls_xor_no_simd(output, input, ivp, 16);

            ret = mbedtls_aes_crypt_ecb(ctx, mode, output, output);
            if (ret != 0) {
                goto exit;
            }
            ivp = output;

            input  += 16;
            output += 16;
            length -= 16;
        }
        memcpy(iv, ivp, 16);
    }
    ret = 0;

exit:
    return ret;
}
#endif /* MBEDTLS_CIPHER_MODE_CBC */

#if defined(MBEDTLS_CIPHER_MODE_XTS)

typedef unsigned char mbedtls_be128[16];

/*
 * GF(2^128) multiplication function
 *
 * This function multiplies a field element by x in the polynomial field
 * representation. It uses 64-bit word operations to gain speed but compensates
 * for machine endianness and hence works correctly on both big and little
 * endian machines.
 */
#if defined(MBEDTLS_AESCE_C) || defined(MBEDTLS_AESNI_C)
MBEDTLS_OPTIMIZE_FOR_PERFORMANCE
#endif
static inline void mbedtls_gf128mul_x_ble(unsigned char r[16],
                                          const unsigned char x[16])
{
    uint64_t a, b, ra, rb;

    a = MBEDTLS_GET_UINT64_LE(x, 0);
    b = MBEDTLS_GET_UINT64_LE(x, 8);

    ra = (a << 1)  ^ 0x0087 >> (8 - ((b >> 63) << 3));
    rb = (a >> 63) | (b << 1);

    MBEDTLS_PUT_UINT64_LE(ra, r, 0);
    MBEDTLS_PUT_UINT64_LE(rb, r, 8);
}

/*
 * AES-XTS buffer encryption/decryption
 *
 * Use of MBEDTLS_OPTIMIZE_FOR_PERFORMANCE here and for mbedtls_gf128mul_x_ble()
 * is a 3x performance improvement for gcc -Os, if we have hardware AES support.
 */
#if defined(MBEDTLS_AESCE_C) || defined(MBEDTLS_AESNI_C)
MBEDTLS_OPTIMIZE_FOR_PERFORMANCE
#endif
int mbedtls_aes_crypt_xts(mbedtls_aes_xts_context *ctx,
                          int mode,
                          size_t length,
                          const unsigned char data_unit[16],
                          const unsigned char *input,
                          unsigned char *output)
{
    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
    size_t blocks = length / 16;
    size_t leftover = length % 16;
    unsigned char tweak[16];
    unsigned char prev_tweak[16];
    unsigned char tmp[16];

    if (mode != MBEDTLS_AES_ENCRYPT && mode != MBEDTLS_AES_DECRYPT) {
        return MBEDTLS_ERR_AES_BAD_INPUT_DATA;
    }

    /* Data units must be at least 16 bytes long. */
    if (length < 16) {
        return MBEDTLS_ERR_AES_INVALID_INPUT_LENGTH;
    }

    /* NIST SP 800-38E disallows data units larger than 2**20 blocks. */
    if (length > (1 << 20) * 16) {
        return MBEDTLS_ERR_AES_INVALID_INPUT_LENGTH;
    }

    /* Compute the tweak. */
    ret = mbedtls_aes_crypt_ecb(&ctx->tweak, MBEDTLS_AES_ENCRYPT,
                                data_unit, tweak);
    if (ret != 0) {
        return ret;
    }

    while (blocks--) {
        if (MBEDTLS_UNLIKELY(leftover && (mode == MBEDTLS_AES_DECRYPT) && blocks == 0)) {
            /* We are on the last block in a decrypt operation that has
             * leftover bytes, so we need to use the next tweak for this block,
             * and this tweak for the leftover bytes. Save the current tweak for
             * the leftovers and then update the current tweak for use on this,
             * the last full block. */
            memcpy(prev_tweak, tweak, sizeof(tweak));
            mbedtls_gf128mul_x_ble(tweak, tweak);
        }

        mbedtls_xor(tmp, input, tweak, 16);

        ret = mbedtls_aes_crypt_ecb(&ctx->crypt, mode, tmp, tmp);
        if (ret != 0) {
            return ret;
        }

        mbedtls_xor(output, tmp, tweak, 16);

        /* Update the tweak for the next block. */
        mbedtls_gf128mul_x_ble(tweak, tweak);

        output += 16;
        input += 16;
    }

    if (leftover) {
        /* If we are on the leftover bytes in a decrypt operation, we need to
         * use the previous tweak for these bytes (as saved in prev_tweak). */
        unsigned char *t = mode == MBEDTLS_AES_DECRYPT ? prev_tweak : tweak;

        /* We are now on the final part of the data unit, which doesn't divide
         * evenly by 16. It's time for ciphertext stealing. */
        size_t i;
        unsigned char *prev_output = output - 16;

        /* Copy ciphertext bytes from the previous block to our output for each
         * byte of ciphertext we won't steal. */
        for (i = 0; i < leftover; i++) {
            output[i] = prev_output[i];
        }

        /* Copy the remainder of the input for this final round. */
        mbedtls_xor(tmp, input, t, leftover);

        /* Copy ciphertext bytes from the previous block for input in this
         * round. */
        mbedtls_xor(tmp + i, prev_output + i, t + i, 16 - i);

        ret = mbedtls_aes_crypt_ecb(&ctx->crypt, mode, tmp, tmp);
        if (ret != 0) {
            return ret;
        }

        /* Write the result back to the previous block, overriding the previous
         * output we copied. */
        mbedtls_xor(prev_output, tmp, t, 16);
    }

    return 0;
}
#endif /* MBEDTLS_CIPHER_MODE_XTS */

#if defined(MBEDTLS_CIPHER_MODE_CFB)
/*
 * AES-CFB128 buffer encryption/decryption
 */
int mbedtls_aes_crypt_cfb128(mbedtls_aes_context *ctx,
                             int mode,
                             size_t length,
                             size_t *iv_off,
                             unsigned char iv[16],
                             const unsigned char *input,
                             unsigned char *output)
{
    int c;
    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
    size_t n;

    if (mode != MBEDTLS_AES_ENCRYPT && mode != MBEDTLS_AES_DECRYPT) {
        return MBEDTLS_ERR_AES_BAD_INPUT_DATA;
    }

    n = *iv_off;

    if (n > 15) {
        return MBEDTLS_ERR_AES_BAD_INPUT_DATA;
    }

    if (mode == MBEDTLS_AES_DECRYPT) {
        while (length--) {
            if (n == 0) {
                ret = mbedtls_aes_crypt_ecb(ctx, MBEDTLS_AES_ENCRYPT, iv, iv);
                if (ret != 0) {
                    goto exit;
                }
            }

            c = *input++;
            *output++ = (unsigned char) (c ^ iv[n]);
            iv[n] = (unsigned char) c;

            n = (n + 1) & 0x0F;
        }
    } else {
        while (length--) {
            if (n == 0) {
                ret = mbedtls_aes_crypt_ecb(ctx, MBEDTLS_AES_ENCRYPT, iv, iv);
                if (ret != 0) {
                    goto exit;
                }
            }

            iv[n] = *output++ = (unsigned char) (iv[n] ^ *input++);

            n = (n + 1) & 0x0F;
        }
    }

    *iv_off = n;
    ret = 0;

exit:
    return ret;
}

/*
 * AES-CFB8 buffer encryption/decryption
 */
int mbedtls_aes_crypt_cfb8(mbedtls_aes_context *ctx,
                           int mode,
                           size_t length,
                           unsigned char iv[16],
                           const unsigned char *input,
                           unsigned char *output)
{
    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
    unsigned char c;
    unsigned char ov[17];

    if (mode != MBEDTLS_AES_ENCRYPT && mode != MBEDTLS_AES_DECRYPT) {
        return MBEDTLS_ERR_AES_BAD_INPUT_DATA;
    }
    while (length--) {
        memcpy(ov, iv, 16);
        ret = mbedtls_aes_crypt_ecb(ctx, MBEDTLS_AES_ENCRYPT, iv, iv);
        if (ret != 0) {
            goto exit;
        }

        if (mode == MBEDTLS_AES_DECRYPT) {
            ov[16] = *input;
        }

        c = *output++ = (unsigned char) (iv[0] ^ *input++);

        if (mode == MBEDTLS_AES_ENCRYPT) {
            ov[16] = c;
        }

        memcpy(iv, ov + 1, 16);
    }
    ret = 0;

exit:
    return ret;
}
#endif /* MBEDTLS_CIPHER_MODE_CFB */

#if defined(MBEDTLS_CIPHER_MODE_OFB)
/*
 * AES-OFB (Output Feedback Mode) buffer encryption/decryption
 */
int mbedtls_aes_crypt_ofb(mbedtls_aes_context *ctx,
                          size_t length,
                          size_t *iv_off,
                          unsigned char iv[16],
                          const unsigned char *input,
                          unsigned char *output)
{
    int ret = 0;
    size_t n;

    n = *iv_off;

    if (n > 15) {
        return MBEDTLS_ERR_AES_BAD_INPUT_DATA;
    }

    while (length--) {
        if (n == 0) {
            ret = mbedtls_aes_crypt_ecb(ctx, MBEDTLS_AES_ENCRYPT, iv, iv);
            if (ret != 0) {
                goto exit;
            }
        }
        *output++ =  *input++ ^ iv[n];

        n = (n + 1) & 0x0F;
    }

    *iv_off = n;

exit:
    return ret;
}
#endif /* MBEDTLS_CIPHER_MODE_OFB */

#if defined(MBEDTLS_CIPHER_MODE_CTR)
/*
 * AES-CTR buffer encryption/decryption
 */
int mbedtls_aes_crypt_ctr(mbedtls_aes_context *ctx,
                          size_t length,
                          size_t *nc_off,
                          unsigned char nonce_counter[16],
                          unsigned char stream_block[16],
                          const unsigned char *input,
                          unsigned char *output)
{
    int c, i;
    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
    size_t n;

    n = *nc_off;

    if (n > 0x0F) {
        return MBEDTLS_ERR_AES_BAD_INPUT_DATA;
    }

    while (length--) {
        if (n == 0) {
            ret = mbedtls_aes_crypt_ecb(ctx, MBEDTLS_AES_ENCRYPT, nonce_counter, stream_block);
            if (ret != 0) {
                goto exit;
            }

            for (i = 16; i > 0; i--) {
                if (++nonce_counter[i - 1] != 0) {
                    break;
                }
            }
        }
        c = *input++;
        *output++ = (unsigned char) (c ^ stream_block[n]);

        n = (n + 1) & 0x0F;
    }

    *nc_off = n;
    ret = 0;

exit:
    return ret;
}
#endif /* MBEDTLS_CIPHER_MODE_CTR */

#endif /* !MBEDTLS_AES_ALT */

#if defined(MBEDTLS_SELF_TEST)
/*
 * AES test vectors from:
 *
 * http://csrc.nist.gov/archive/aes/rijndael/rijndael-vals.zip
 */
static const unsigned char aes_test_ecb_dec[][16] =
{
    { 0x44, 0x41, 0x6A, 0xC2, 0xD1, 0xF5, 0x3C, 0x58,
      0x33, 0x03, 0x91, 0x7E, 0x6B, 0xE9, 0xEB, 0xE0 },
#if !defined(MBEDTLS_AES_ONLY_128_BIT_KEY_LENGTH)
    { 0x48, 0xE3, 0x1E, 0x9E, 0x25, 0x67, 0x18, 0xF2,
      0x92, 0x29, 0x31, 0x9C, 0x19, 0xF1, 0x5B, 0xA4 },
    { 0x05, 0x8C, 0xCF, 0xFD, 0xBB, 0xCB, 0x38, 0x2D,
      0x1F, 0x6F, 0x56, 0x58, 0x5D, 0x8A, 0x4A, 0xDE }
#endif
};

static const unsigned char aes_test_ecb_enc[][16] =
{
    { 0xC3, 0x4C, 0x05, 0x2C, 0xC0, 0xDA, 0x8D, 0x73,
      0x45, 0x1A, 0xFE, 0x5F, 0x03, 0xBE, 0x29, 0x7F },
#if !defined(MBEDTLS_AES_ONLY_128_BIT_KEY_LENGTH)
    { 0xF3, 0xF6, 0x75, 0x2A, 0xE8, 0xD7, 0x83, 0x11,
      0x38, 0xF0, 0x41, 0x56, 0x06, 0x31, 0xB1, 0x14 },
    { 0x8B, 0x79, 0xEE, 0xCC, 0x93, 0xA0, 0xEE, 0x5D,
      0xFF, 0x30, 0xB4, 0xEA, 0x21, 0x63, 0x6D, 0xA4 }
#endif
};

#if defined(MBEDTLS_CIPHER_MODE_CBC)
static const unsigned char aes_test_cbc_dec[][16] =
{
    { 0xFA, 0xCA, 0x37, 0xE0, 0xB0, 0xC8, 0x53, 0x73,
      0xDF, 0x70, 0x6E, 0x73, 0xF7, 0xC9, 0xAF, 0x86 },
#if !defined(MBEDTLS_AES_ONLY_128_BIT_KEY_LENGTH)
    { 0x5D, 0xF6, 0x78, 0xDD, 0x17, 0xBA, 0x4E, 0x75,
      0xB6, 0x17, 0x68, 0xC6, 0xAD, 0xEF, 0x7C, 0x7B },
    { 0x48, 0x04, 0xE1, 0x81, 0x8F, 0xE6, 0x29, 0x75,
      0x19, 0xA3, 0xE8, 0x8C, 0x57, 0x31, 0x04, 0x13 }
#endif
};

static const unsigned char aes_test_cbc_enc[][16] =
{
    { 0x8A, 0x05, 0xFC, 0x5E, 0x09, 0x5A, 0xF4, 0x84,
      0x8A, 0x08, 0xD3, 0x28, 0xD3, 0x68, 0x8E, 0x3D },
#if !defined(MBEDTLS_AES_ONLY_128_BIT_KEY_LENGTH)
    { 0x7B, 0xD9, 0x66, 0xD5, 0x3A, 0xD8, 0xC1, 0xBB,
      0x85, 0xD2, 0xAD, 0xFA, 0xE8, 0x7B, 0xB1, 0x04 },
    { 0xFE, 0x3C, 0x53, 0x65, 0x3E, 0x2F, 0x45, 0xB5,
      0x6F, 0xCD, 0x88, 0xB2, 0xCC, 0x89, 0x8F, 0xF0 }
#endif
};
#endif /* MBEDTLS_CIPHER_MODE_CBC */

#if defined(MBEDTLS_CIPHER_MODE_CFB)
/*
 * AES-CFB128 test vectors from:
 *
 * http://csrc.nist.gov/publications/nistpubs/800-38a/sp800-38a.pdf
 */
static const unsigned char aes_test_cfb128_key[][32] =
{
    { 0x2B, 0x7E, 0x15, 0x16, 0x28, 0xAE, 0xD2, 0xA6,
      0xAB, 0xF7, 0x15, 0x88, 0x09, 0xCF, 0x4F, 0x3C },
#if !defined(MBEDTLS_AES_ONLY_128_BIT_KEY_LENGTH)
    { 0x8E, 0x73, 0xB0, 0xF7, 0xDA, 0x0E, 0x64, 0x52,
      0xC8, 0x10, 0xF3, 0x2B, 0x80, 0x90, 0x79, 0xE5,
      0x62, 0xF8, 0xEA, 0xD2, 0x52, 0x2C, 0x6B, 0x7B },
    { 0x60, 0x3D, 0xEB, 0x10, 0x15, 0xCA, 0x71, 0xBE,
      0x2B, 0x73, 0xAE, 0xF0, 0x85, 0x7D, 0x77, 0x81,
      0x1F, 0x35, 0x2C, 0x07, 0x3B, 0x61, 0x08, 0xD7,
      0x2D, 0x98, 0x10, 0xA3, 0x09, 0x14, 0xDF, 0xF4 }
#endif
};

static const unsigned char aes_test_cfb128_iv[16] =
{
    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
    0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F
};

static const unsigned char aes_test_cfb128_pt[64] =
{
    0x6B, 0xC1, 0xBE, 0xE2, 0x2E, 0x40, 0x9F, 0x96,
    0xE9, 0x3D, 0x7E, 0x11, 0x73, 0x93, 0x17, 0x2A,
    0xAE, 0x2D, 0x8A, 0x57, 0x1E, 0x03, 0xAC, 0x9C,
    0x9E, 0xB7, 0x6F, 0xAC, 0x45, 0xAF, 0x8E, 0x51,
    0x30, 0xC8, 0x1C, 0x46, 0xA3, 0x5C, 0xE4, 0x11,
    0xE5, 0xFB, 0xC1, 0x19, 0x1A, 0x0A, 0x52, 0xEF,
    0xF6, 0x9F, 0x24, 0x45, 0xDF, 0x4F, 0x9B, 0x17,
    0xAD, 0x2B, 0x41, 0x7B, 0xE6, 0x6C, 0x37, 0x10
};

static const unsigned char aes_test_cfb128_ct[][64] =
{
    { 0x3B, 0x3F, 0xD9, 0x2E, 0xB7, 0x2D, 0xAD, 0x20,
      0x33, 0x34, 0x49, 0xF8, 0xE8, 0x3C, 0xFB, 0x4A,
      0xC8, 0xA6, 0x45, 0x37, 0xA0, 0xB3, 0xA9, 0x3F,
      0xCD, 0xE3, 0xCD, 0xAD, 0x9F, 0x1C, 0xE5, 0x8B,
      0x26, 0x75, 0x1F, 0x67, 0xA3, 0xCB, 0xB1, 0x40,
      0xB1, 0x80, 0x8C, 0xF1, 0x87, 0xA4, 0xF4, 0xDF,
      0xC0, 0x4B, 0x05, 0x35, 0x7C, 0x5D, 0x1C, 0x0E,
      0xEA, 0xC4, 0xC6, 0x6F, 0x9F, 0xF7, 0xF2, 0xE6 },
#if !defined(MBEDTLS_AES_ONLY_128_BIT_KEY_LENGTH)
    { 0xCD, 0xC8, 0x0D, 0x6F, 0xDD, 0xF1, 0x8C, 0xAB,
      0x34, 0xC2, 0x59, 0x09, 0xC9, 0x9A, 0x41, 0x74,
      0x67, 0xCE, 0x7F, 0x7F, 0x81, 0x17, 0x36, 0x21,
      0x96, 0x1A, 0x2B, 0x70, 0x17, 0x1D, 0x3D, 0x7A,
      0x2E, 0x1E, 0x8A, 0x1D, 0xD5, 0x9B, 0x88, 0xB1,
      0xC8, 0xE6, 0x0F, 0xED, 0x1E, 0xFA, 0xC4, 0xC9,
      0xC0, 0x5F, 0x9F, 0x9C, 0xA9, 0x83, 0x4F, 0xA0,
      0x42, 0xAE, 0x8F, 0xBA, 0x58, 0x4B, 0x09, 0xFF },
    { 0xDC, 0x7E, 0x84, 0xBF, 0xDA, 0x79, 0x16, 0x4B,
      0x7E, 0xCD, 0x84, 0x86, 0x98, 0x5D, 0x38, 0x60,
      0x39, 0xFF, 0xED, 0x14, 0x3B, 0x28, 0xB1, 0xC8,
      0x32, 0x11, 0x3C, 0x63, 0x31, 0xE5, 0x40, 0x7B,
      0xDF, 0x10, 0x13, 0x24, 0x15, 0xE5, 0x4B, 0x92,
      0xA1, 0x3E, 0xD0, 0xA8, 0x26, 0x7A, 0xE2, 0xF9,
      0x75, 0xA3, 0x85, 0x74, 0x1A, 0xB9, 0xCE, 0xF8,
      0x20, 0x31, 0x62, 0x3D, 0x55, 0xB1, 0xE4, 0x71 }
#endif
};
#endif /* MBEDTLS_CIPHER_MODE_CFB */

#if defined(MBEDTLS_CIPHER_MODE_OFB)
/*
 * AES-OFB test vectors from:
 *
 * https://csrc.nist.gov/publications/detail/sp/800-38a/final
 */
static const unsigned char aes_test_ofb_key[][32] =
{
    { 0x2B, 0x7E, 0x15, 0x16, 0x28, 0xAE, 0xD2, 0xA6,
      0xAB, 0xF7, 0x15, 0x88, 0x09, 0xCF, 0x4F, 0x3C },
#if !defined(MBEDTLS_AES_ONLY_128_BIT_KEY_LENGTH)
    { 0x8E, 0x73, 0xB0, 0xF7, 0xDA, 0x0E, 0x64, 0x52,
      0xC8, 0x10, 0xF3, 0x2B, 0x80, 0x90, 0x79, 0xE5,
      0x62, 0xF8, 0xEA, 0xD2, 0x52, 0x2C, 0x6B, 0x7B },
    { 0x60, 0x3D, 0xEB, 0x10, 0x15, 0xCA, 0x71, 0xBE,
      0x2B, 0x73, 0xAE, 0xF0, 0x85, 0x7D, 0x77, 0x81,
      0x1F, 0x35, 0x2C, 0x07, 0x3B, 0x61, 0x08, 0xD7,
      0x2D, 0x98, 0x10, 0xA3, 0x09, 0x14, 0xDF, 0xF4 }
#endif
};

static const unsigned char aes_test_ofb_iv[16] =
{
    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
    0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F
};

static const unsigned char aes_test_ofb_pt[64] =
{
    0x6B, 0xC1, 0xBE, 0xE2, 0x2E, 0x40, 0x9F, 0x96,
    0xE9, 0x3D, 0x7E, 0x11, 0x73, 0x93, 0x17, 0x2A,
    0xAE, 0x2D, 0x8A, 0x57, 0x1E, 0x03, 0xAC, 0x9C,
    0x9E, 0xB7, 0x6F, 0xAC, 0x45, 0xAF, 0x8E, 0x51,
    0x30, 0xC8, 0x1C, 0x46, 0xA3, 0x5C, 0xE4, 0x11,
    0xE5, 0xFB, 0xC1, 0x19, 0x1A, 0x0A, 0x52, 0xEF,
    0xF6, 0x9F, 0x24, 0x45, 0xDF, 0x4F, 0x9B, 0x17,
    0xAD, 0x2B, 0x41, 0x7B, 0xE6, 0x6C, 0x37, 0x10
};

static const unsigned char aes_test_ofb_ct[][64] =
{
    { 0x3B, 0x3F, 0xD9, 0x2E, 0xB7, 0x2D, 0xAD, 0x20,
      0x33, 0x34, 0x49, 0xF8, 0xE8, 0x3C, 0xFB, 0x4A,
      0x77, 0x89, 0x50, 0x8d, 0x16, 0x91, 0x8f, 0x03,
      0xf5, 0x3c, 0x52, 0xda, 0xc5, 0x4e, 0xd8, 0x25,
      0x97, 0x40, 0x05, 0x1e, 0x9c, 0x5f, 0xec, 0xf6,
      0x43, 0x44, 0xf7, 0xa8, 0x22, 0x60, 0xed, 0xcc,
      0x30, 0x4c, 0x65, 0x28, 0xf6, 0x59, 0xc7, 0x78,
      0x66, 0xa5, 0x10, 0xd9, 0xc1, 0xd6, 0xae, 0x5e },
#if !defined(MBEDTLS_AES_ONLY_128_BIT_KEY_LENGTH)
    { 0xCD, 0xC8, 0x0D, 0x6F, 0xDD, 0xF1, 0x8C, 0xAB,
      0x34, 0xC2, 0x59, 0x09, 0xC9, 0x9A, 0x41, 0x74,
      0xfc, 0xc2, 0x8b, 0x8d, 0x4c, 0x63, 0x83, 0x7c,
      0x09, 0xe8, 0x17, 0x00, 0xc1, 0x10, 0x04, 0x01,
      0x8d, 0x9a, 0x9a, 0xea, 0xc0, 0xf6, 0x59, 0x6f,
      0x55, 0x9c, 0x6d, 0x4d, 0xaf, 0x59, 0xa5, 0xf2,
      0x6d, 0x9f, 0x20, 0x08, 0x57, 0xca, 0x6c, 0x3e,
      0x9c, 0xac, 0x52, 0x4b, 0xd9, 0xac, 0xc9, 0x2a },
    { 0xDC, 0x7E, 0x84, 0xBF, 0xDA, 0x79, 0x16, 0x4B,
      0x7E, 0xCD, 0x84, 0x86, 0x98, 0x5D, 0x38, 0x60,
      0x4f, 0xeb, 0xdc, 0x67, 0x40, 0xd2, 0x0b, 0x3a,
      0xc8, 0x8f, 0x6a, 0xd8, 0x2a, 0x4f, 0xb0, 0x8d,
      0x71, 0xab, 0x47, 0xa0, 0x86, 0xe8, 0x6e, 0xed,
      0xf3, 0x9d, 0x1c, 0x5b, 0xba, 0x97, 0xc4, 0x08,
      0x01, 0x26, 0x14, 0x1d, 0x67, 0xf3, 0x7b, 0xe8,
      0x53, 0x8f, 0x5a, 0x8b, 0xe7, 0x40, 0xe4, 0x84 }
#endif
};
#endif /* MBEDTLS_CIPHER_MODE_OFB */

#if defined(MBEDTLS_CIPHER_MODE_CTR)
/*
 * AES-CTR test vectors from:
 *
 * http://www.faqs.org/rfcs/rfc3686.html
 */

static const unsigned char aes_test_ctr_key[][16] =
{
    { 0xAE, 0x68, 0x52, 0xF8, 0x12, 0x10, 0x67, 0xCC,
      0x4B, 0xF7, 0xA5, 0x76, 0x55, 0x77, 0xF3, 0x9E },
    { 0x7E, 0x24, 0x06, 0x78, 0x17, 0xFA, 0xE0, 0xD7,
      0x43, 0xD6, 0xCE, 0x1F, 0x32, 0x53, 0x91, 0x63 },
    { 0x76, 0x91, 0xBE, 0x03, 0x5E, 0x50, 0x20, 0xA8,
      0xAC, 0x6E, 0x61, 0x85, 0x29, 0xF9, 0xA0, 0xDC }
};

static const unsigned char aes_test_ctr_nonce_counter[][16] =
{
    { 0x00, 0x00, 0x00, 0x30, 0x00, 0x00, 0x00, 0x00,
      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01 },
    { 0x00, 0x6C, 0xB6, 0xDB, 0xC0, 0x54, 0x3B, 0x59,
      0xDA, 0x48, 0xD9, 0x0B, 0x00, 0x00, 0x00, 0x01 },
    { 0x00, 0xE0, 0x01, 0x7B, 0x27, 0x77, 0x7F, 0x3F,
      0x4A, 0x17, 0x86, 0xF0, 0x00, 0x00, 0x00, 0x01 }
};

static const unsigned char aes_test_ctr_pt[][48] =
{
    { 0x53, 0x69, 0x6E, 0x67, 0x6C, 0x65, 0x20, 0x62,
      0x6C, 0x6F, 0x63, 0x6B, 0x20, 0x6D, 0x73, 0x67 },
    { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
      0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F,
      0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
      0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F },

    { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
      0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F,
      0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
      0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F,
      0x20, 0x21, 0x22, 0x23 }
};

static const unsigned char aes_test_ctr_ct[][48] =
{
    { 0xE4, 0x09, 0x5D, 0x4F, 0xB7, 0xA7, 0xB3, 0x79,
      0x2D, 0x61, 0x75, 0xA3, 0x26, 0x13, 0x11, 0xB8 },
    { 0x51, 0x04, 0xA1, 0x06, 0x16, 0x8A, 0x72, 0xD9,
      0x79, 0x0D, 0x41, 0xEE, 0x8E, 0xDA, 0xD3, 0x88,
      0xEB, 0x2E, 0x1E, 0xFC, 0x46, 0xDA, 0x57, 0xC8,
      0xFC, 0xE6, 0x30, 0xDF, 0x91, 0x41, 0xBE, 0x28 },
    { 0xC1, 0xCF, 0x48, 0xA8, 0x9F, 0x2F, 0xFD, 0xD9,
      0xCF, 0x46, 0x52, 0xE9, 0xEF, 0xDB, 0x72, 0xD7,
      0x45, 0x40, 0xA4, 0x2B, 0xDE, 0x6D, 0x78, 0x36,
      0xD5, 0x9A, 0x5C, 0xEA, 0xAE, 0xF3, 0x10, 0x53,
      0x25, 0xB2, 0x07, 0x2F }
};

static const int aes_test_ctr_len[3] =
{ 16, 32, 36 };
#endif /* MBEDTLS_CIPHER_MODE_CTR */

#if defined(MBEDTLS_CIPHER_MODE_XTS)
/*
 * AES-XTS test vectors from:
 *
 * IEEE P1619/D16 Annex B
 * https://web.archive.org/web/20150629024421/http://grouper.ieee.org/groups/1619/email/pdf00086.pdf
 * (Archived from original at http://grouper.ieee.org/groups/1619/email/pdf00086.pdf)
 */
static const unsigned char aes_test_xts_key[][32] =
{
    { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
    { 0x11, 0x11, 0x11, 0x11, 0x11, 0x11, 0x11, 0x11,
      0x11, 0x11, 0x11, 0x11, 0x11, 0x11, 0x11, 0x11,
      0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22,
      0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22 },
    { 0xff, 0xfe, 0xfd, 0xfc, 0xfb, 0xfa, 0xf9, 0xf8,
      0xf7, 0xf6, 0xf5, 0xf4, 0xf3, 0xf2, 0xf1, 0xf0,
      0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22,
      0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22 },
};

static const unsigned char aes_test_xts_pt32[][32] =
{
    { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
    { 0x44, 0x44, 0x44, 0x44, 0x44, 0x44, 0x44, 0x44,
      0x44, 0x44, 0x44, 0x44, 0x44, 0x44, 0x44, 0x44,
      0x44, 0x44, 0x44, 0x44, 0x44, 0x44, 0x44, 0x44,
      0x44, 0x44, 0x44, 0x44, 0x44, 0x44, 0x44, 0x44 },
    { 0x44, 0x44, 0x44, 0x44, 0x44, 0x44, 0x44, 0x44,
      0x44, 0x44, 0x44, 0x44, 0x44, 0x44, 0x44, 0x44,
      0x44, 0x44, 0x44, 0x44, 0x44, 0x44, 0x44, 0x44,
      0x44, 0x44, 0x44, 0x44, 0x44, 0x44, 0x44, 0x44 },
};

static const unsigned char aes_test_xts_ct32[][32] =
{
    { 0x91, 0x7c, 0xf6, 0x9e, 0xbd, 0x68, 0xb2, 0xec,
      0x9b, 0x9f, 0xe9, 0xa3, 0xea, 0xdd, 0xa6, 0x92,
      0xcd, 0x43, 0xd2, 0xf5, 0x95, 0x98, 0xed, 0x85,
      0x8c, 0x02, 0xc2, 0x65, 0x2f, 0xbf, 0x92, 0x2e },
    { 0xc4, 0x54, 0x18, 0x5e, 0x6a, 0x16, 0x93, 0x6e,
      0x39, 0x33, 0x40, 0x38, 0xac, 0xef, 0x83, 0x8b,
      0xfb, 0x18, 0x6f, 0xff, 0x74, 0x80, 0xad, 0xc4,
      0x28, 0x93, 0x82, 0xec, 0xd6, 0xd3, 0x94, 0xf0 },
    { 0xaf, 0x85, 0x33, 0x6b, 0x59, 0x7a, 0xfc, 0x1a,
      0x90, 0x0b, 0x2e, 0xb2, 0x1e, 0xc9, 0x49, 0xd2,
      0x92, 0xdf, 0x4c, 0x04, 0x7e, 0x0b, 0x21, 0x53,
      0x21, 0x86, 0xa5, 0x97, 0x1a, 0x22, 0x7a, 0x89 },
};

static const unsigned char aes_test_xts_data_unit[][16] =
{
    { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
    { 0x33, 0x33, 0x33, 0x33, 0x33, 0x00, 0x00, 0x00,
      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
    { 0x33, 0x33, 0x33, 0x33, 0x33, 0x00, 0x00, 0x00,
      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
};

#endif /* MBEDTLS_CIPHER_MODE_XTS */

/*
 * Checkup routine
 */
int mbedtls_aes_self_test(int verbose)
{
    int ret = 0, i, j, u, mode;
    unsigned int keybits;
    unsigned char key[32];
    unsigned char buf[64];
    const unsigned char *aes_tests;
#if defined(MBEDTLS_CIPHER_MODE_CBC) || defined(MBEDTLS_CIPHER_MODE_CFB) || \
    defined(MBEDTLS_CIPHER_MODE_OFB)
    unsigned char iv[16];
#endif
#if defined(MBEDTLS_CIPHER_MODE_CBC)
    unsigned char prv[16];
#endif
#if defined(MBEDTLS_CIPHER_MODE_CTR) || defined(MBEDTLS_CIPHER_MODE_CFB) || \
    defined(MBEDTLS_CIPHER_MODE_OFB)
    size_t offset;
#endif
#if defined(MBEDTLS_CIPHER_MODE_CTR) || defined(MBEDTLS_CIPHER_MODE_XTS)
    int len;
#endif
#if defined(MBEDTLS_CIPHER_MODE_CTR)
    unsigned char nonce_counter[16];
    unsigned char stream_block[16];
#endif
    mbedtls_aes_context ctx;

    memset(key, 0, 32);
    mbedtls_aes_init(&ctx);

    if (verbose != 0) {
#if defined(MBEDTLS_AES_ALT)
        mbedtls_printf("  AES note: alternative implementation.\n");
#else /* MBEDTLS_AES_ALT */
#if defined(MBEDTLS_AESNI_HAVE_CODE)
#if MBEDTLS_AESNI_HAVE_CODE == 1
        mbedtls_printf("  AES note: AESNI code present (assembly implementation).\n");
#elif MBEDTLS_AESNI_HAVE_CODE == 2
        mbedtls_printf("  AES note: AESNI code present (intrinsics implementation).\n");
#else
#error "Unrecognised value for MBEDTLS_AESNI_HAVE_CODE"
#endif
        if (mbedtls_aesni_has_support(MBEDTLS_AESNI_AES)) {
            mbedtls_printf("  AES note: using AESNI.\n");
        } else
#endif
#if defined(MBEDTLS_VIA_PADLOCK_HAVE_CODE)
        if (mbedtls_padlock_has_support(MBEDTLS_PADLOCK_ACE)) {
            mbedtls_printf("  AES note: using VIA Padlock.\n");
        } else
#endif
#if defined(MBEDTLS_AESCE_HAVE_CODE)
        if (MBEDTLS_AESCE_HAS_SUPPORT()) {
            mbedtls_printf("  AES note: using AESCE.\n");
        } else
#endif
        {
#if !defined(MBEDTLS_AES_USE_HARDWARE_ONLY)
            mbedtls_printf("  AES note: built-in implementation.\n");
#endif
        }
#endif /* MBEDTLS_AES_ALT */
    }

    /*
     * ECB mode
     */
    {
        static const int num_tests =
            sizeof(aes_test_ecb_dec) / sizeof(*aes_test_ecb_dec);

        for (i = 0; i < num_tests << 1; i++) {
            u = i >> 1;
            keybits = 128 + u * 64;
            mode = i & 1;

            if (verbose != 0) {
                mbedtls_printf("  AES-ECB-%3u (%s): ", keybits,
                               (mode == MBEDTLS_AES_DECRYPT) ? "dec" : "enc");
            }

            memset(buf, 0, 16);

            if (mode == MBEDTLS_AES_DECRYPT) {
                ret = mbedtls_aes_setkey_dec(&ctx, key, keybits);
                aes_tests = aes_test_ecb_dec[u];
            } else {
                ret = mbedtls_aes_setkey_enc(&ctx, key, keybits);
                aes_tests = aes_test_ecb_enc[u];
            }

            /*
             * AES-192 is an optional feature that may be unavailable when
             * there is an alternative underlying implementation i.e. when
             * MBEDTLS_AES_ALT is defined.
             */
            if (ret == MBEDTLS_ERR_PLATFORM_FEATURE_UNSUPPORTED && keybits == 192) {
                mbedtls_printf("skipped\n");
                continue;
            } else if (ret != 0) {
                goto exit;
            }

            for (j = 0; j < 10000; j++) {
                ret = mbedtls_aes_crypt_ecb(&ctx, mode, buf, buf);
                if (ret != 0) {
                    goto exit;
                }
            }

            if (memcmp(buf, aes_tests, 16) != 0) {
                ret = 1;
                goto exit;
            }

            if (verbose != 0) {
                mbedtls_printf("passed\n");
            }
        }

        if (verbose != 0) {
            mbedtls_printf("\n");
        }
    }

#if defined(MBEDTLS_CIPHER_MODE_CBC)
    /*
     * CBC mode
     */
    {
        static const int num_tests =
            sizeof(aes_test_cbc_dec) / sizeof(*aes_test_cbc_dec);

        for (i = 0; i < num_tests << 1; i++) {
            u = i >> 1;
            keybits = 128 + u * 64;
            mode = i & 1;

            if (verbose != 0) {
                mbedtls_printf("  AES-CBC-%3u (%s): ", keybits,
                               (mode == MBEDTLS_AES_DECRYPT) ? "dec" : "enc");
            }

            memset(iv, 0, 16);
            memset(prv, 0, 16);
            memset(buf, 0, 16);

            if (mode == MBEDTLS_AES_DECRYPT) {
                ret = mbedtls_aes_setkey_dec(&ctx, key, keybits);
                aes_tests = aes_test_cbc_dec[u];
            } else {
                ret = mbedtls_aes_setkey_enc(&ctx, key, keybits);
                aes_tests = aes_test_cbc_enc[u];
            }

            /*
             * AES-192 is an optional feature that may be unavailable when
             * there is an alternative underlying implementation i.e. when
             * MBEDTLS_AES_ALT is defined.
             */
            if (ret == MBEDTLS_ERR_PLATFORM_FEATURE_UNSUPPORTED && keybits == 192) {
                mbedtls_printf("skipped\n");
                continue;
            } else if (ret != 0) {
                goto exit;
            }

            for (j = 0; j < 10000; j++) {
                if (mode == MBEDTLS_AES_ENCRYPT) {
                    unsigned char tmp[16];

                    memcpy(tmp, prv, 16);
                    memcpy(prv, buf, 16);
                    memcpy(buf, tmp, 16);
                }

                ret = mbedtls_aes_crypt_cbc(&ctx, mode, 16, iv, buf, buf);
                if (ret != 0) {
                    goto exit;
                }

            }

            if (memcmp(buf, aes_tests, 16) != 0) {
                ret = 1;
                goto exit;
            }

            if (verbose != 0) {
                mbedtls_printf("passed\n");
            }
        }

        if (verbose != 0) {
            mbedtls_printf("\n");
        }
    }
#endif /* MBEDTLS_CIPHER_MODE_CBC */

#if defined(MBEDTLS_CIPHER_MODE_CFB)
    /*
     * CFB128 mode
     */
    {
        static const int num_tests =
            sizeof(aes_test_cfb128_key) / sizeof(*aes_test_cfb128_key);

        for (i = 0; i < num_tests << 1; i++) {
            u = i >> 1;
            keybits = 128 + u * 64;
            mode = i & 1;

            if (verbose != 0) {
                mbedtls_printf("  AES-CFB128-%3u (%s): ", keybits,
                               (mode == MBEDTLS_AES_DECRYPT) ? "dec" : "enc");
            }

            memcpy(iv,  aes_test_cfb128_iv, 16);
            memcpy(key, aes_test_cfb128_key[u], keybits / 8);

            offset = 0;
            ret = mbedtls_aes_setkey_enc(&ctx, key, keybits);
            /*
             * AES-192 is an optional feature that may be unavailable when
             * there is an alternative underlying implementation i.e. when
             * MBEDTLS_AES_ALT is defined.
             */
            if (ret == MBEDTLS_ERR_PLATFORM_FEATURE_UNSUPPORTED && keybits == 192) {
                mbedtls_printf("skipped\n");
                continue;
            } else if (ret != 0) {
                goto exit;
            }

            if (mode == MBEDTLS_AES_DECRYPT) {
                memcpy(buf, aes_test_cfb128_ct[u], 64);
                aes_tests = aes_test_cfb128_pt;
            } else {
                memcpy(buf, aes_test_cfb128_pt, 64);
                aes_tests = aes_test_cfb128_ct[u];
            }

            ret = mbedtls_aes_crypt_cfb128(&ctx, mode, 64, &offset, iv, buf, buf);
            if (ret != 0) {
                goto exit;
            }

            if (memcmp(buf, aes_tests, 64) != 0) {
                ret = 1;
                goto exit;
            }

            if (verbose != 0) {
                mbedtls_printf("passed\n");
            }
        }

        if (verbose != 0) {
            mbedtls_printf("\n");
        }
    }
#endif /* MBEDTLS_CIPHER_MODE_CFB */

#if defined(MBEDTLS_CIPHER_MODE_OFB)
    /*
     * OFB mode
     */
    {
        static const int num_tests =
            sizeof(aes_test_ofb_key) / sizeof(*aes_test_ofb_key);

        for (i = 0; i < num_tests << 1; i++) {
            u = i >> 1;
            keybits = 128 + u * 64;
            mode = i & 1;

            if (verbose != 0) {
                mbedtls_printf("  AES-OFB-%3u (%s): ", keybits,
                               (mode == MBEDTLS_AES_DECRYPT) ? "dec" : "enc");
            }

            memcpy(iv,  aes_test_ofb_iv, 16);
            memcpy(key, aes_test_ofb_key[u], keybits / 8);

            offset = 0;
            ret = mbedtls_aes_setkey_enc(&ctx, key, keybits);
            /*
             * AES-192 is an optional feature that may be unavailable when
             * there is an alternative underlying implementation i.e. when
             * MBEDTLS_AES_ALT is defined.
             */
            if (ret == MBEDTLS_ERR_PLATFORM_FEATURE_UNSUPPORTED && keybits == 192) {
                mbedtls_printf("skipped\n");
                continue;
            } else if (ret != 0) {
                goto exit;
            }

            if (mode == MBEDTLS_AES_DECRYPT) {
                memcpy(buf, aes_test_ofb_ct[u], 64);
                aes_tests = aes_test_ofb_pt;
            } else {
                memcpy(buf, aes_test_ofb_pt, 64);
                aes_tests = aes_test_ofb_ct[u];
            }

            ret = mbedtls_aes_crypt_ofb(&ctx, 64, &offset, iv, buf, buf);
            if (ret != 0) {
                goto exit;
            }

            if (memcmp(buf, aes_tests, 64) != 0) {
                ret = 1;
                goto exit;
            }

            if (verbose != 0) {
                mbedtls_printf("passed\n");
            }
        }

        if (verbose != 0) {
            mbedtls_printf("\n");
        }
    }
#endif /* MBEDTLS_CIPHER_MODE_OFB */

#if defined(MBEDTLS_CIPHER_MODE_CTR)
    /*
     * CTR mode
     */
    {
        static const int num_tests =
            sizeof(aes_test_ctr_key) / sizeof(*aes_test_ctr_key);

        for (i = 0; i < num_tests << 1; i++) {
            u = i >> 1;
            mode = i & 1;

            if (verbose != 0) {
                mbedtls_printf("  AES-CTR-128 (%s): ",
                               (mode == MBEDTLS_AES_DECRYPT) ? "dec" : "enc");
            }

            memcpy(nonce_counter, aes_test_ctr_nonce_counter[u], 16);
            memcpy(key, aes_test_ctr_key[u], 16);

            offset = 0;
            if ((ret = mbedtls_aes_setkey_enc(&ctx, key, 128)) != 0) {
                goto exit;
            }

            len = aes_test_ctr_len[u];

            if (mode == MBEDTLS_AES_DECRYPT) {
                memcpy(buf, aes_test_ctr_ct[u], len);
                aes_tests = aes_test_ctr_pt[u];
            } else {
                memcpy(buf, aes_test_ctr_pt[u], len);
                aes_tests = aes_test_ctr_ct[u];
            }

            ret = mbedtls_aes_crypt_ctr(&ctx, len, &offset, nonce_counter,
                                        stream_block, buf, buf);
            if (ret != 0) {
                goto exit;
            }

            if (memcmp(buf, aes_tests, len) != 0) {
                ret = 1;
                goto exit;
            }

            if (verbose != 0) {
                mbedtls_printf("passed\n");
            }
        }
    }

    if (verbose != 0) {
        mbedtls_printf("\n");
    }
#endif /* MBEDTLS_CIPHER_MODE_CTR */

#if defined(MBEDTLS_CIPHER_MODE_XTS)
    /*
     * XTS mode
     */
    {
        static const int num_tests =
            sizeof(aes_test_xts_key) / sizeof(*aes_test_xts_key);
        mbedtls_aes_xts_context ctx_xts;

        mbedtls_aes_xts_init(&ctx_xts);

        for (i = 0; i < num_tests << 1; i++) {
            const unsigned char *data_unit;
            u = i >> 1;
            mode = i & 1;

            if (verbose != 0) {
                mbedtls_printf("  AES-XTS-128 (%s): ",
                               (mode == MBEDTLS_AES_DECRYPT) ? "dec" : "enc");
            }

            memset(key, 0, sizeof(key));
            memcpy(key, aes_test_xts_key[u], 32);
            data_unit = aes_test_xts_data_unit[u];

            len = sizeof(*aes_test_xts_ct32);

            if (mode == MBEDTLS_AES_DECRYPT) {
                ret = mbedtls_aes_xts_setkey_dec(&ctx_xts, key, 256);
                if (ret != 0) {
                    goto exit;
                }
                memcpy(buf, aes_test_xts_ct32[u], len);
                aes_tests = aes_test_xts_pt32[u];
            } else {
                ret = mbedtls_aes_xts_setkey_enc(&ctx_xts, key, 256);
                if (ret != 0) {
                    goto exit;
                }
                memcpy(buf, aes_test_xts_pt32[u], len);
                aes_tests = aes_test_xts_ct32[u];
            }


            ret = mbedtls_aes_crypt_xts(&ctx_xts, mode, len, data_unit,
                                        buf, buf);
            if (ret != 0) {
                goto exit;
            }

            if (memcmp(buf, aes_tests, len) != 0) {
                ret = 1;
                goto exit;
            }

            if (verbose != 0) {
                mbedtls_printf("passed\n");
            }
        }

        if (verbose != 0) {
            mbedtls_printf("\n");
        }

        mbedtls_aes_xts_free(&ctx_xts);
    }
#endif /* MBEDTLS_CIPHER_MODE_XTS */

    ret = 0;

exit:
    if (ret != 0 && verbose != 0) {
        mbedtls_printf("failed\n");
    }

    mbedtls_aes_free(&ctx);

    return ret;
}

#endif /* MBEDTLS_SELF_TEST */

#endif /* MBEDTLS_AES_C */