Diff: system/crypto/aes.cpp

Revision:

1:352f608c3337

Child:

5:1e9f6a365854

diff -r 92bca02df485 -r 352f608c3337 system/crypto/aes.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/system/crypto/aes.cpp	Thu Nov 26 12:59:52 2015 +0000
@@ -0,0 +1,936 @@
+/*
+ ---------------------------------------------------------------------------
+ Copyright (c) 1998-2008, Brian Gladman, Worcester, UK. All rights reserved.
+
+ LICENSE TERMS
+
+ The redistribution and use of this software (with or without changes)
+ is allowed without the payment of fees or royalties provided that:
+
+  1. source code distributions include the above copyright notice, this
+     list of conditions and the following disclaimer;
+
+  2. binary distributions include the above copyright notice, this list
+     of conditions and the following disclaimer in their documentation;
+
+  3. the name of the copyright holder is not used to endorse products
+     built using this software without specific written permission.
+
+ DISCLAIMER
+
+ This software is provided 'as is' with no explicit or implied warranties
+ in respect of its properties, including, but not limited to, correctness
+ and/or fitness for purpose.
+ ---------------------------------------------------------------------------
+ Issue 09/09/2006
+
+ This is an AES implementation that uses only 8-bit byte operations on the
+ cipher state (there are options to use 32-bit types if available).
+
+ The combination of mix columns and byte substitution used here is based on
+ that developed by Karl Malbrain. His contribution is acknowledged.
+ */
+
+/* define if you have a fast memcpy function on your system */
+#if 0
+#  define HAVE_MEMCPY
+#  include <string.h>
+#  if defined( _MSC_VER )
+#    include <intrin.h>
+#    pragma intrinsic( memcpy )
+#  endif
+#endif
+
+
+#include <stdlib.h>
+#include <stdint.h>
+
+/* define if you have fast 32-bit types on your system */
+#if 1
+#  define HAVE_UINT_32T
+#endif
+
+/* define if you don't want any tables */
+#if 1
+#  define USE_TABLES
+#endif
+
+/*  On Intel Core 2 duo VERSION_1 is faster */
+
+/* alternative versions (test for performance on your system) */
+#if 1
+#  define VERSION_1
+#endif
+
+#include "aes.h"
+
+//#if defined( HAVE_UINT_32T )
+//  typedef unsigned long uint32_t;
+//#endif
+
+/* functions for finite field multiplication in the AES Galois field    */
+
+#define WPOLY   0x011b
+#define BPOLY     0x1b
+#define DPOLY   0x008d
+
+#define f1(x)   (x)
+#define f2(x)   ((x << 1) ^ (((x >> 7) & 1) * WPOLY))
+#define f4(x)   ((x << 2) ^ (((x >> 6) & 1) * WPOLY) ^ (((x >> 6) & 2) * WPOLY))
+#define f8(x)   ((x << 3) ^ (((x >> 5) & 1) * WPOLY) ^ (((x >> 5) & 2) * WPOLY) \
+                          ^ (((x >> 5) & 4) * WPOLY))
+#define d2(x)   (((x) >> 1) ^ ((x) & 1 ? DPOLY : 0))
+
+#define f3(x)   (f2(x) ^ x)
+#define f9(x)   (f8(x) ^ x)
+#define fb(x)   (f8(x) ^ f2(x) ^ x)
+#define fd(x)   (f8(x) ^ f4(x) ^ x)
+#define fe(x)   (f8(x) ^ f4(x) ^ f2(x))
+
+#if defined( USE_TABLES )
+
+#define sb_data(w) {    /* S Box data values */                            \
+    w(0x63), w(0x7c), w(0x77), w(0x7b), w(0xf2), w(0x6b), w(0x6f), w(0xc5),\
+    w(0x30), w(0x01), w(0x67), w(0x2b), w(0xfe), w(0xd7), w(0xab), w(0x76),\
+    w(0xca), w(0x82), w(0xc9), w(0x7d), w(0xfa), w(0x59), w(0x47), w(0xf0),\
+    w(0xad), w(0xd4), w(0xa2), w(0xaf), w(0x9c), w(0xa4), w(0x72), w(0xc0),\
+    w(0xb7), w(0xfd), w(0x93), w(0x26), w(0x36), w(0x3f), w(0xf7), w(0xcc),\
+    w(0x34), w(0xa5), w(0xe5), w(0xf1), w(0x71), w(0xd8), w(0x31), w(0x15),\
+    w(0x04), w(0xc7), w(0x23), w(0xc3), w(0x18), w(0x96), w(0x05), w(0x9a),\
+    w(0x07), w(0x12), w(0x80), w(0xe2), w(0xeb), w(0x27), w(0xb2), w(0x75),\
+    w(0x09), w(0x83), w(0x2c), w(0x1a), w(0x1b), w(0x6e), w(0x5a), w(0xa0),\
+    w(0x52), w(0x3b), w(0xd6), w(0xb3), w(0x29), w(0xe3), w(0x2f), w(0x84),\
+    w(0x53), w(0xd1), w(0x00), w(0xed), w(0x20), w(0xfc), w(0xb1), w(0x5b),\
+    w(0x6a), w(0xcb), w(0xbe), w(0x39), w(0x4a), w(0x4c), w(0x58), w(0xcf),\
+    w(0xd0), w(0xef), w(0xaa), w(0xfb), w(0x43), w(0x4d), w(0x33), w(0x85),\
+    w(0x45), w(0xf9), w(0x02), w(0x7f), w(0x50), w(0x3c), w(0x9f), w(0xa8),\
+    w(0x51), w(0xa3), w(0x40), w(0x8f), w(0x92), w(0x9d), w(0x38), w(0xf5),\
+    w(0xbc), w(0xb6), w(0xda), w(0x21), w(0x10), w(0xff), w(0xf3), w(0xd2),\
+    w(0xcd), w(0x0c), w(0x13), w(0xec), w(0x5f), w(0x97), w(0x44), w(0x17),\
+    w(0xc4), w(0xa7), w(0x7e), w(0x3d), w(0x64), w(0x5d), w(0x19), w(0x73),\
+    w(0x60), w(0x81), w(0x4f), w(0xdc), w(0x22), w(0x2a), w(0x90), w(0x88),\
+    w(0x46), w(0xee), w(0xb8), w(0x14), w(0xde), w(0x5e), w(0x0b), w(0xdb),\
+    w(0xe0), w(0x32), w(0x3a), w(0x0a), w(0x49), w(0x06), w(0x24), w(0x5c),\
+    w(0xc2), w(0xd3), w(0xac), w(0x62), w(0x91), w(0x95), w(0xe4), w(0x79),\
+    w(0xe7), w(0xc8), w(0x37), w(0x6d), w(0x8d), w(0xd5), w(0x4e), w(0xa9),\
+    w(0x6c), w(0x56), w(0xf4), w(0xea), w(0x65), w(0x7a), w(0xae), w(0x08),\
+    w(0xba), w(0x78), w(0x25), w(0x2e), w(0x1c), w(0xa6), w(0xb4), w(0xc6),\
+    w(0xe8), w(0xdd), w(0x74), w(0x1f), w(0x4b), w(0xbd), w(0x8b), w(0x8a),\
+    w(0x70), w(0x3e), w(0xb5), w(0x66), w(0x48), w(0x03), w(0xf6), w(0x0e),\
+    w(0x61), w(0x35), w(0x57), w(0xb9), w(0x86), w(0xc1), w(0x1d), w(0x9e),\
+    w(0xe1), w(0xf8), w(0x98), w(0x11), w(0x69), w(0xd9), w(0x8e), w(0x94),\
+    w(0x9b), w(0x1e), w(0x87), w(0xe9), w(0xce), w(0x55), w(0x28), w(0xdf),\
+    w(0x8c), w(0xa1), w(0x89), w(0x0d), w(0xbf), w(0xe6), w(0x42), w(0x68),\
+    w(0x41), w(0x99), w(0x2d), w(0x0f), w(0xb0), w(0x54), w(0xbb), w(0x16) }
+
+#define isb_data(w) {   /* inverse S Box data values */                    \
+    w(0x52), w(0x09), w(0x6a), w(0xd5), w(0x30), w(0x36), w(0xa5), w(0x38),\
+    w(0xbf), w(0x40), w(0xa3), w(0x9e), w(0x81), w(0xf3), w(0xd7), w(0xfb),\
+    w(0x7c), w(0xe3), w(0x39), w(0x82), w(0x9b), w(0x2f), w(0xff), w(0x87),\
+    w(0x34), w(0x8e), w(0x43), w(0x44), w(0xc4), w(0xde), w(0xe9), w(0xcb),\
+    w(0x54), w(0x7b), w(0x94), w(0x32), w(0xa6), w(0xc2), w(0x23), w(0x3d),\
+    w(0xee), w(0x4c), w(0x95), w(0x0b), w(0x42), w(0xfa), w(0xc3), w(0x4e),\
+    w(0x08), w(0x2e), w(0xa1), w(0x66), w(0x28), w(0xd9), w(0x24), w(0xb2),\
+    w(0x76), w(0x5b), w(0xa2), w(0x49), w(0x6d), w(0x8b), w(0xd1), w(0x25),\
+    w(0x72), w(0xf8), w(0xf6), w(0x64), w(0x86), w(0x68), w(0x98), w(0x16),\
+    w(0xd4), w(0xa4), w(0x5c), w(0xcc), w(0x5d), w(0x65), w(0xb6), w(0x92),\
+    w(0x6c), w(0x70), w(0x48), w(0x50), w(0xfd), w(0xed), w(0xb9), w(0xda),\
+    w(0x5e), w(0x15), w(0x46), w(0x57), w(0xa7), w(0x8d), w(0x9d), w(0x84),\
+    w(0x90), w(0xd8), w(0xab), w(0x00), w(0x8c), w(0xbc), w(0xd3), w(0x0a),\
+    w(0xf7), w(0xe4), w(0x58), w(0x05), w(0xb8), w(0xb3), w(0x45), w(0x06),\
+    w(0xd0), w(0x2c), w(0x1e), w(0x8f), w(0xca), w(0x3f), w(0x0f), w(0x02),\
+    w(0xc1), w(0xaf), w(0xbd), w(0x03), w(0x01), w(0x13), w(0x8a), w(0x6b),\
+    w(0x3a), w(0x91), w(0x11), w(0x41), w(0x4f), w(0x67), w(0xdc), w(0xea),\
+    w(0x97), w(0xf2), w(0xcf), w(0xce), w(0xf0), w(0xb4), w(0xe6), w(0x73),\
+    w(0x96), w(0xac), w(0x74), w(0x22), w(0xe7), w(0xad), w(0x35), w(0x85),\
+    w(0xe2), w(0xf9), w(0x37), w(0xe8), w(0x1c), w(0x75), w(0xdf), w(0x6e),\
+    w(0x47), w(0xf1), w(0x1a), w(0x71), w(0x1d), w(0x29), w(0xc5), w(0x89),\
+    w(0x6f), w(0xb7), w(0x62), w(0x0e), w(0xaa), w(0x18), w(0xbe), w(0x1b),\
+    w(0xfc), w(0x56), w(0x3e), w(0x4b), w(0xc6), w(0xd2), w(0x79), w(0x20),\
+    w(0x9a), w(0xdb), w(0xc0), w(0xfe), w(0x78), w(0xcd), w(0x5a), w(0xf4),\
+    w(0x1f), w(0xdd), w(0xa8), w(0x33), w(0x88), w(0x07), w(0xc7), w(0x31),\
+    w(0xb1), w(0x12), w(0x10), w(0x59), w(0x27), w(0x80), w(0xec), w(0x5f),\
+    w(0x60), w(0x51), w(0x7f), w(0xa9), w(0x19), w(0xb5), w(0x4a), w(0x0d),\
+    w(0x2d), w(0xe5), w(0x7a), w(0x9f), w(0x93), w(0xc9), w(0x9c), w(0xef),\
+    w(0xa0), w(0xe0), w(0x3b), w(0x4d), w(0xae), w(0x2a), w(0xf5), w(0xb0),\
+    w(0xc8), w(0xeb), w(0xbb), w(0x3c), w(0x83), w(0x53), w(0x99), w(0x61),\
+    w(0x17), w(0x2b), w(0x04), w(0x7e), w(0xba), w(0x77), w(0xd6), w(0x26),\
+    w(0xe1), w(0x69), w(0x14), w(0x63), w(0x55), w(0x21), w(0x0c), w(0x7d) }
+
+#define mm_data(w) {    /* basic data for forming finite field tables */   \
+    w(0x00), w(0x01), w(0x02), w(0x03), w(0x04), w(0x05), w(0x06), w(0x07),\
+    w(0x08), w(0x09), w(0x0a), w(0x0b), w(0x0c), w(0x0d), w(0x0e), w(0x0f),\
+    w(0x10), w(0x11), w(0x12), w(0x13), w(0x14), w(0x15), w(0x16), w(0x17),\
+    w(0x18), w(0x19), w(0x1a), w(0x1b), w(0x1c), w(0x1d), w(0x1e), w(0x1f),\
+    w(0x20), w(0x21), w(0x22), w(0x23), w(0x24), w(0x25), w(0x26), w(0x27),\
+    w(0x28), w(0x29), w(0x2a), w(0x2b), w(0x2c), w(0x2d), w(0x2e), w(0x2f),\
+    w(0x30), w(0x31), w(0x32), w(0x33), w(0x34), w(0x35), w(0x36), w(0x37),\
+    w(0x38), w(0x39), w(0x3a), w(0x3b), w(0x3c), w(0x3d), w(0x3e), w(0x3f),\
+    w(0x40), w(0x41), w(0x42), w(0x43), w(0x44), w(0x45), w(0x46), w(0x47),\
+    w(0x48), w(0x49), w(0x4a), w(0x4b), w(0x4c), w(0x4d), w(0x4e), w(0x4f),\
+    w(0x50), w(0x51), w(0x52), w(0x53), w(0x54), w(0x55), w(0x56), w(0x57),\
+    w(0x58), w(0x59), w(0x5a), w(0x5b), w(0x5c), w(0x5d), w(0x5e), w(0x5f),\
+    w(0x60), w(0x61), w(0x62), w(0x63), w(0x64), w(0x65), w(0x66), w(0x67),\
+    w(0x68), w(0x69), w(0x6a), w(0x6b), w(0x6c), w(0x6d), w(0x6e), w(0x6f),\
+    w(0x70), w(0x71), w(0x72), w(0x73), w(0x74), w(0x75), w(0x76), w(0x77),\
+    w(0x78), w(0x79), w(0x7a), w(0x7b), w(0x7c), w(0x7d), w(0x7e), w(0x7f),\
+    w(0x80), w(0x81), w(0x82), w(0x83), w(0x84), w(0x85), w(0x86), w(0x87),\
+    w(0x88), w(0x89), w(0x8a), w(0x8b), w(0x8c), w(0x8d), w(0x8e), w(0x8f),\
+    w(0x90), w(0x91), w(0x92), w(0x93), w(0x94), w(0x95), w(0x96), w(0x97),\
+    w(0x98), w(0x99), w(0x9a), w(0x9b), w(0x9c), w(0x9d), w(0x9e), w(0x9f),\
+    w(0xa0), w(0xa1), w(0xa2), w(0xa3), w(0xa4), w(0xa5), w(0xa6), w(0xa7),\
+    w(0xa8), w(0xa9), w(0xaa), w(0xab), w(0xac), w(0xad), w(0xae), w(0xaf),\
+    w(0xb0), w(0xb1), w(0xb2), w(0xb3), w(0xb4), w(0xb5), w(0xb6), w(0xb7),\
+    w(0xb8), w(0xb9), w(0xba), w(0xbb), w(0xbc), w(0xbd), w(0xbe), w(0xbf),\
+    w(0xc0), w(0xc1), w(0xc2), w(0xc3), w(0xc4), w(0xc5), w(0xc6), w(0xc7),\
+    w(0xc8), w(0xc9), w(0xca), w(0xcb), w(0xcc), w(0xcd), w(0xce), w(0xcf),\
+    w(0xd0), w(0xd1), w(0xd2), w(0xd3), w(0xd4), w(0xd5), w(0xd6), w(0xd7),\
+    w(0xd8), w(0xd9), w(0xda), w(0xdb), w(0xdc), w(0xdd), w(0xde), w(0xdf),\
+    w(0xe0), w(0xe1), w(0xe2), w(0xe3), w(0xe4), w(0xe5), w(0xe6), w(0xe7),\
+    w(0xe8), w(0xe9), w(0xea), w(0xeb), w(0xec), w(0xed), w(0xee), w(0xef),\
+    w(0xf0), w(0xf1), w(0xf2), w(0xf3), w(0xf4), w(0xf5), w(0xf6), w(0xf7),\
+    w(0xf8), w(0xf9), w(0xfa), w(0xfb), w(0xfc), w(0xfd), w(0xfe), w(0xff) }
+
+static const uint8_t sbox[256]  =  sb_data(f1);
+
+#if defined( AES_DEC_PREKEYED )
+static const uint8_t isbox[256] = isb_data(f1);
+#endif
+
+static const uint8_t gfm2_sbox[256] = sb_data(f2);
+static const uint8_t gfm3_sbox[256] = sb_data(f3);
+
+#if defined( AES_DEC_PREKEYED )
+static const uint8_t gfmul_9[256] = mm_data(f9);
+static const uint8_t gfmul_b[256] = mm_data(fb);
+static const uint8_t gfmul_d[256] = mm_data(fd);
+static const uint8_t gfmul_e[256] = mm_data(fe);
+#endif
+
+#define s_box(x)     sbox[(x)]
+#if defined( AES_DEC_PREKEYED )
+#define is_box(x)    isbox[(x)]
+#endif
+#define gfm2_sb(x)   gfm2_sbox[(x)]
+#define gfm3_sb(x)   gfm3_sbox[(x)]
+#if defined( AES_DEC_PREKEYED )
+#define gfm_9(x)     gfmul_9[(x)]
+#define gfm_b(x)     gfmul_b[(x)]
+#define gfm_d(x)     gfmul_d[(x)]
+#define gfm_e(x)     gfmul_e[(x)]
+#endif
+#else
+
+/* this is the high bit of x right shifted by 1 */
+/* position. Since the starting polynomial has  */
+/* 9 bits (0x11b), this right shift keeps the   */
+/* values of all top bits within a byte         */
+
+static uint8_t hibit(const uint8_t x)
+{   uint8_t r = (uint8_t)((x >> 1) | (x >> 2));
+
+    r |= (r >> 2);
+    r |= (r >> 4);
+    return (r + 1) >> 1;
+}
+
+/* return the inverse of the finite field element x */
+
+static uint8_t gf_inv(const uint8_t x)
+{   uint8_t p1 = x, p2 = BPOLY, n1 = hibit(x), n2 = 0x80, v1 = 1, v2 = 0;
+
+    if(x < 2) 
+        return x;
+
+    for( ; ; )
+    {
+        if(n1)
+            while(n2 >= n1)             /* divide polynomial p2 by p1    */
+            {
+                n2 /= n1;               /* shift smaller polynomial left */ 
+                p2 ^= (p1 * n2) & 0xff; /* and remove from larger one    */
+                v2 ^= (v1 * n2);        /* shift accumulated value and   */ 
+                n2 = hibit(p2);         /* add into result               */
+            }
+        else
+            return v1;
+
+        if(n2)                          /* repeat with values swapped    */ 
+            while(n1 >= n2)
+            {
+                n1 /= n2; 
+                p1 ^= p2 * n1; 
+                v1 ^= v2 * n1; 
+                n1 = hibit(p1);
+            }
+        else
+            return v2;
+    }
+}
+
+/* The forward and inverse affine transformations used in the S-box */
+uint8_t fwd_affine(const uint8_t x)
+{   
+#if defined( HAVE_UINT_32T )
+    uint32_t w = x;
+    w ^= (w << 1) ^ (w << 2) ^ (w << 3) ^ (w << 4);
+    return 0x63 ^ ((w ^ (w >> 8)) & 0xff);
+#else
+    return 0x63 ^ x ^ (x << 1) ^ (x << 2) ^ (x << 3) ^ (x << 4) 
+                    ^ (x >> 7) ^ (x >> 6) ^ (x >> 5) ^ (x >> 4);
+#endif
+}
+
+uint8_t inv_affine(const uint8_t x)
+{
+#if defined( HAVE_UINT_32T )
+    uint32_t w = x;
+    w = (w << 1) ^ (w << 3) ^ (w << 6);
+    return 0x05 ^ ((w ^ (w >> 8)) & 0xff);
+#else
+    return 0x05 ^ (x << 1) ^ (x << 3) ^ (x << 6) 
+                ^ (x >> 7) ^ (x >> 5) ^ (x >> 2);
+#endif
+}
+
+#define s_box(x)   fwd_affine(gf_inv(x))
+#define is_box(x)  gf_inv(inv_affine(x))
+#define gfm2_sb(x) f2(s_box(x))
+#define gfm3_sb(x) f3(s_box(x))
+#define gfm_9(x)   f9(x)
+#define gfm_b(x)   fb(x)
+#define gfm_d(x)   fd(x)
+#define gfm_e(x)   fe(x)
+
+#endif
+
+#if defined( HAVE_MEMCPY )
+#  define block_copy_nn(d, s, l)    memcpy(d, s, l)
+#  define block_copy(d, s)          memcpy(d, s, N_BLOCK)
+#else
+#  define block_copy_nn(d, s, l)    copy_block_nn(d, s, l)
+#  define block_copy(d, s)          copy_block(d, s)
+#endif
+
+static void copy_block( void *d, const void *s )
+{
+#if defined( HAVE_UINT_32T )
+    ((uint32_t*)d)[ 0] = ((uint32_t*)s)[ 0];
+    ((uint32_t*)d)[ 1] = ((uint32_t*)s)[ 1];
+    ((uint32_t*)d)[ 2] = ((uint32_t*)s)[ 2];
+    ((uint32_t*)d)[ 3] = ((uint32_t*)s)[ 3];
+#else
+    ((uint8_t*)d)[ 0] = ((uint8_t*)s)[ 0];
+    ((uint8_t*)d)[ 1] = ((uint8_t*)s)[ 1];
+    ((uint8_t*)d)[ 2] = ((uint8_t*)s)[ 2];
+    ((uint8_t*)d)[ 3] = ((uint8_t*)s)[ 3];
+    ((uint8_t*)d)[ 4] = ((uint8_t*)s)[ 4];
+    ((uint8_t*)d)[ 5] = ((uint8_t*)s)[ 5];
+    ((uint8_t*)d)[ 6] = ((uint8_t*)s)[ 6];
+    ((uint8_t*)d)[ 7] = ((uint8_t*)s)[ 7];
+    ((uint8_t*)d)[ 8] = ((uint8_t*)s)[ 8];
+    ((uint8_t*)d)[ 9] = ((uint8_t*)s)[ 9];
+    ((uint8_t*)d)[10] = ((uint8_t*)s)[10];
+    ((uint8_t*)d)[11] = ((uint8_t*)s)[11];
+    ((uint8_t*)d)[12] = ((uint8_t*)s)[12];
+    ((uint8_t*)d)[13] = ((uint8_t*)s)[13];
+    ((uint8_t*)d)[14] = ((uint8_t*)s)[14];
+    ((uint8_t*)d)[15] = ((uint8_t*)s)[15];
+#endif
+}
+
+static void copy_block_nn( uint8_t * d, const uint8_t *s, uint8_t nn )
+{
+    while( nn-- )
+        //*((uint8_t*)d)++ = *((uint8_t*)s)++;
+        *d++ = *s++;
+}
+
+static void xor_block( void *d, const void *s )
+{
+#if defined( HAVE_UINT_32T )
+    ((uint32_t*)d)[ 0] ^= ((uint32_t*)s)[ 0];
+    ((uint32_t*)d)[ 1] ^= ((uint32_t*)s)[ 1];
+    ((uint32_t*)d)[ 2] ^= ((uint32_t*)s)[ 2];
+    ((uint32_t*)d)[ 3] ^= ((uint32_t*)s)[ 3];
+#else
+    ((uint8_t*)d)[ 0] ^= ((uint8_t*)s)[ 0];
+    ((uint8_t*)d)[ 1] ^= ((uint8_t*)s)[ 1];
+    ((uint8_t*)d)[ 2] ^= ((uint8_t*)s)[ 2];
+    ((uint8_t*)d)[ 3] ^= ((uint8_t*)s)[ 3];
+    ((uint8_t*)d)[ 4] ^= ((uint8_t*)s)[ 4];
+    ((uint8_t*)d)[ 5] ^= ((uint8_t*)s)[ 5];
+    ((uint8_t*)d)[ 6] ^= ((uint8_t*)s)[ 6];
+    ((uint8_t*)d)[ 7] ^= ((uint8_t*)s)[ 7];
+    ((uint8_t*)d)[ 8] ^= ((uint8_t*)s)[ 8];
+    ((uint8_t*)d)[ 9] ^= ((uint8_t*)s)[ 9];
+    ((uint8_t*)d)[10] ^= ((uint8_t*)s)[10];
+    ((uint8_t*)d)[11] ^= ((uint8_t*)s)[11];
+    ((uint8_t*)d)[12] ^= ((uint8_t*)s)[12];
+    ((uint8_t*)d)[13] ^= ((uint8_t*)s)[13];
+    ((uint8_t*)d)[14] ^= ((uint8_t*)s)[14];
+    ((uint8_t*)d)[15] ^= ((uint8_t*)s)[15];
+#endif
+}
+
+static void copy_and_key( void *d, const void *s, const void *k )
+{
+#if defined( HAVE_UINT_32T )
+    ((uint32_t*)d)[ 0] = ((uint32_t*)s)[ 0] ^ ((uint32_t*)k)[ 0];
+    ((uint32_t*)d)[ 1] = ((uint32_t*)s)[ 1] ^ ((uint32_t*)k)[ 1];
+    ((uint32_t*)d)[ 2] = ((uint32_t*)s)[ 2] ^ ((uint32_t*)k)[ 2];
+    ((uint32_t*)d)[ 3] = ((uint32_t*)s)[ 3] ^ ((uint32_t*)k)[ 3];
+#elif 1
+    ((uint8_t*)d)[ 0] = ((uint8_t*)s)[ 0] ^ ((uint8_t*)k)[ 0];
+    ((uint8_t*)d)[ 1] = ((uint8_t*)s)[ 1] ^ ((uint8_t*)k)[ 1];
+    ((uint8_t*)d)[ 2] = ((uint8_t*)s)[ 2] ^ ((uint8_t*)k)[ 2];
+    ((uint8_t*)d)[ 3] = ((uint8_t*)s)[ 3] ^ ((uint8_t*)k)[ 3];
+    ((uint8_t*)d)[ 4] = ((uint8_t*)s)[ 4] ^ ((uint8_t*)k)[ 4];
+    ((uint8_t*)d)[ 5] = ((uint8_t*)s)[ 5] ^ ((uint8_t*)k)[ 5];
+    ((uint8_t*)d)[ 6] = ((uint8_t*)s)[ 6] ^ ((uint8_t*)k)[ 6];
+    ((uint8_t*)d)[ 7] = ((uint8_t*)s)[ 7] ^ ((uint8_t*)k)[ 7];
+    ((uint8_t*)d)[ 8] = ((uint8_t*)s)[ 8] ^ ((uint8_t*)k)[ 8];
+    ((uint8_t*)d)[ 9] = ((uint8_t*)s)[ 9] ^ ((uint8_t*)k)[ 9];
+    ((uint8_t*)d)[10] = ((uint8_t*)s)[10] ^ ((uint8_t*)k)[10];
+    ((uint8_t*)d)[11] = ((uint8_t*)s)[11] ^ ((uint8_t*)k)[11];
+    ((uint8_t*)d)[12] = ((uint8_t*)s)[12] ^ ((uint8_t*)k)[12];
+    ((uint8_t*)d)[13] = ((uint8_t*)s)[13] ^ ((uint8_t*)k)[13];
+    ((uint8_t*)d)[14] = ((uint8_t*)s)[14] ^ ((uint8_t*)k)[14];
+    ((uint8_t*)d)[15] = ((uint8_t*)s)[15] ^ ((uint8_t*)k)[15];
+#else
+    block_copy(d, s);
+    xor_block(d, k);
+#endif
+}
+
+static void add_round_key( uint8_t d[N_BLOCK], const uint8_t k[N_BLOCK] )
+{
+    xor_block(d, k);
+}
+
+static void shift_sub_rows( uint8_t st[N_BLOCK] )
+{   uint8_t tt;
+
+    st[ 0] = s_box(st[ 0]); st[ 4] = s_box(st[ 4]);
+    st[ 8] = s_box(st[ 8]); st[12] = s_box(st[12]);
+
+    tt = st[1]; st[ 1] = s_box(st[ 5]); st[ 5] = s_box(st[ 9]);
+    st[ 9] = s_box(st[13]); st[13] = s_box( tt );
+
+    tt = st[2]; st[ 2] = s_box(st[10]); st[10] = s_box( tt );
+    tt = st[6]; st[ 6] = s_box(st[14]); st[14] = s_box( tt );
+
+    tt = st[15]; st[15] = s_box(st[11]); st[11] = s_box(st[ 7]);
+    st[ 7] = s_box(st[ 3]); st[ 3] = s_box( tt );
+}
+
+#if defined( AES_DEC_PREKEYED )
+
+static void inv_shift_sub_rows( uint8_t st[N_BLOCK] )
+{   uint8_t tt;
+
+    st[ 0] = is_box(st[ 0]); st[ 4] = is_box(st[ 4]);
+    st[ 8] = is_box(st[ 8]); st[12] = is_box(st[12]);
+
+    tt = st[13]; st[13] = is_box(st[9]); st[ 9] = is_box(st[5]);
+    st[ 5] = is_box(st[1]); st[ 1] = is_box( tt );
+
+    tt = st[2]; st[ 2] = is_box(st[10]); st[10] = is_box( tt );
+    tt = st[6]; st[ 6] = is_box(st[14]); st[14] = is_box( tt );
+
+    tt = st[3]; st[ 3] = is_box(st[ 7]); st[ 7] = is_box(st[11]);
+    st[11] = is_box(st[15]); st[15] = is_box( tt );
+}
+
+#endif
+
+#if defined( VERSION_1 )
+  static void mix_sub_columns( uint8_t dt[N_BLOCK] )
+  { uint8_t st[N_BLOCK];
+    block_copy(st, dt);
+#else
+  static void mix_sub_columns( uint8_t dt[N_BLOCK], uint8_t st[N_BLOCK] )
+  {
+#endif
+    dt[ 0] = gfm2_sb(st[0]) ^ gfm3_sb(st[5]) ^ s_box(st[10]) ^ s_box(st[15]);
+    dt[ 1] = s_box(st[0]) ^ gfm2_sb(st[5]) ^ gfm3_sb(st[10]) ^ s_box(st[15]);
+    dt[ 2] = s_box(st[0]) ^ s_box(st[5]) ^ gfm2_sb(st[10]) ^ gfm3_sb(st[15]);
+    dt[ 3] = gfm3_sb(st[0]) ^ s_box(st[5]) ^ s_box(st[10]) ^ gfm2_sb(st[15]);
+
+    dt[ 4] = gfm2_sb(st[4]) ^ gfm3_sb(st[9]) ^ s_box(st[14]) ^ s_box(st[3]);
+    dt[ 5] = s_box(st[4]) ^ gfm2_sb(st[9]) ^ gfm3_sb(st[14]) ^ s_box(st[3]);
+    dt[ 6] = s_box(st[4]) ^ s_box(st[9]) ^ gfm2_sb(st[14]) ^ gfm3_sb(st[3]);
+    dt[ 7] = gfm3_sb(st[4]) ^ s_box(st[9]) ^ s_box(st[14]) ^ gfm2_sb(st[3]);
+
+    dt[ 8] = gfm2_sb(st[8]) ^ gfm3_sb(st[13]) ^ s_box(st[2]) ^ s_box(st[7]);
+    dt[ 9] = s_box(st[8]) ^ gfm2_sb(st[13]) ^ gfm3_sb(st[2]) ^ s_box(st[7]);
+    dt[10] = s_box(st[8]) ^ s_box(st[13]) ^ gfm2_sb(st[2]) ^ gfm3_sb(st[7]);
+    dt[11] = gfm3_sb(st[8]) ^ s_box(st[13]) ^ s_box(st[2]) ^ gfm2_sb(st[7]);
+
+    dt[12] = gfm2_sb(st[12]) ^ gfm3_sb(st[1]) ^ s_box(st[6]) ^ s_box(st[11]);
+    dt[13] = s_box(st[12]) ^ gfm2_sb(st[1]) ^ gfm3_sb(st[6]) ^ s_box(st[11]);
+    dt[14] = s_box(st[12]) ^ s_box(st[1]) ^ gfm2_sb(st[6]) ^ gfm3_sb(st[11]);
+    dt[15] = gfm3_sb(st[12]) ^ s_box(st[1]) ^ s_box(st[6]) ^ gfm2_sb(st[11]);
+  }
+
+#if defined( AES_DEC_PREKEYED )
+
+#if defined( VERSION_1 )
+  static void inv_mix_sub_columns( uint8_t dt[N_BLOCK] )
+  { uint8_t st[N_BLOCK];
+    block_copy(st, dt);
+#else
+  static void inv_mix_sub_columns( uint8_t dt[N_BLOCK], uint8_t st[N_BLOCK] )
+  {
+#endif
+    dt[ 0] = is_box(gfm_e(st[ 0]) ^ gfm_b(st[ 1]) ^ gfm_d(st[ 2]) ^ gfm_9(st[ 3]));
+    dt[ 5] = is_box(gfm_9(st[ 0]) ^ gfm_e(st[ 1]) ^ gfm_b(st[ 2]) ^ gfm_d(st[ 3]));
+    dt[10] = is_box(gfm_d(st[ 0]) ^ gfm_9(st[ 1]) ^ gfm_e(st[ 2]) ^ gfm_b(st[ 3]));
+    dt[15] = is_box(gfm_b(st[ 0]) ^ gfm_d(st[ 1]) ^ gfm_9(st[ 2]) ^ gfm_e(st[ 3]));
+
+    dt[ 4] = is_box(gfm_e(st[ 4]) ^ gfm_b(st[ 5]) ^ gfm_d(st[ 6]) ^ gfm_9(st[ 7]));
+    dt[ 9] = is_box(gfm_9(st[ 4]) ^ gfm_e(st[ 5]) ^ gfm_b(st[ 6]) ^ gfm_d(st[ 7]));
+    dt[14] = is_box(gfm_d(st[ 4]) ^ gfm_9(st[ 5]) ^ gfm_e(st[ 6]) ^ gfm_b(st[ 7]));
+    dt[ 3] = is_box(gfm_b(st[ 4]) ^ gfm_d(st[ 5]) ^ gfm_9(st[ 6]) ^ gfm_e(st[ 7]));
+
+    dt[ 8] = is_box(gfm_e(st[ 8]) ^ gfm_b(st[ 9]) ^ gfm_d(st[10]) ^ gfm_9(st[11]));
+    dt[13] = is_box(gfm_9(st[ 8]) ^ gfm_e(st[ 9]) ^ gfm_b(st[10]) ^ gfm_d(st[11]));
+    dt[ 2] = is_box(gfm_d(st[ 8]) ^ gfm_9(st[ 9]) ^ gfm_e(st[10]) ^ gfm_b(st[11]));
+    dt[ 7] = is_box(gfm_b(st[ 8]) ^ gfm_d(st[ 9]) ^ gfm_9(st[10]) ^ gfm_e(st[11]));
+
+    dt[12] = is_box(gfm_e(st[12]) ^ gfm_b(st[13]) ^ gfm_d(st[14]) ^ gfm_9(st[15]));
+    dt[ 1] = is_box(gfm_9(st[12]) ^ gfm_e(st[13]) ^ gfm_b(st[14]) ^ gfm_d(st[15]));
+    dt[ 6] = is_box(gfm_d(st[12]) ^ gfm_9(st[13]) ^ gfm_e(st[14]) ^ gfm_b(st[15]));
+    dt[11] = is_box(gfm_b(st[12]) ^ gfm_d(st[13]) ^ gfm_9(st[14]) ^ gfm_e(st[15]));
+  }
+
+#endif
+
+#if defined( AES_ENC_PREKEYED ) || defined( AES_DEC_PREKEYED )
+
+/*  Set the cipher key for the pre-keyed version */
+
+return_type aes_set_key( const uint8_t key[], length_type keylen, aes_context ctx[1] )
+{
+    uint8_t cc, rc, hi;
+
+    switch( keylen )
+    {
+    case 16:
+    case 24:
+    case 32:
+        break;
+    default: 
+        ctx->rnd = 0; 
+        return ( uint8_t )-1;
+    }
+    block_copy_nn(ctx->ksch, key, keylen);
+    hi = (keylen + 28) << 2;
+    ctx->rnd = (hi >> 4) - 1;
+    for( cc = keylen, rc = 1; cc < hi; cc += 4 )
+    {   uint8_t tt, t0, t1, t2, t3;
+
+        t0 = ctx->ksch[cc - 4];
+        t1 = ctx->ksch[cc - 3];
+        t2 = ctx->ksch[cc - 2];
+        t3 = ctx->ksch[cc - 1];
+        if( cc % keylen == 0 )
+        {
+            tt = t0;
+            t0 = s_box(t1) ^ rc;
+            t1 = s_box(t2);
+            t2 = s_box(t3);
+            t3 = s_box(tt);
+            rc = f2(rc);
+        }
+        else if( keylen > 24 && cc % keylen == 16 )
+        {
+            t0 = s_box(t0);
+            t1 = s_box(t1);
+            t2 = s_box(t2);
+            t3 = s_box(t3);
+        }
+        tt = cc - keylen;
+        ctx->ksch[cc + 0] = ctx->ksch[tt + 0] ^ t0;
+        ctx->ksch[cc + 1] = ctx->ksch[tt + 1] ^ t1;
+        ctx->ksch[cc + 2] = ctx->ksch[tt + 2] ^ t2;
+        ctx->ksch[cc + 3] = ctx->ksch[tt + 3] ^ t3;
+    }
+    return 0;
+}
+
+#endif
+
+#if defined( AES_ENC_PREKEYED )
+
+/*  Encrypt a single block of 16 bytes */
+
+return_type aes_encrypt( const uint8_t in[N_BLOCK], uint8_t  out[N_BLOCK], const aes_context ctx[1] )
+{
+    if( ctx->rnd )
+    {
+        uint8_t s1[N_BLOCK], r;
+        copy_and_key( s1, in, ctx->ksch );
+
+        for( r = 1 ; r < ctx->rnd ; ++r )
+#if defined( VERSION_1 )
+        {
+            mix_sub_columns( s1 );
+            add_round_key( s1, ctx->ksch + r * N_BLOCK);
+        }
+#else
+        {   uint8_t s2[N_BLOCK];
+            mix_sub_columns( s2, s1 );
+            copy_and_key( s1, s2, ctx->ksch + r * N_BLOCK);
+        }
+#endif
+        shift_sub_rows( s1 );
+        copy_and_key( out, s1, ctx->ksch + r * N_BLOCK );
+    }
+    else
+        return ( uint8_t )-1;
+    return 0;
+}
+
+/* CBC encrypt a number of blocks (input and return an IV) */
+
+return_type aes_cbc_encrypt( const uint8_t *in, uint8_t *out,
+                         int32_t n_block, uint8_t iv[N_BLOCK], const aes_context ctx[1] )
+{
+
+    while(n_block--)
+    {
+        xor_block(iv, in);
+        if(aes_encrypt(iv, iv, ctx) != EXIT_SUCCESS)
+            return EXIT_FAILURE;
+        //memcpy(out, iv, N_BLOCK);
+        block_copy(out, iv);
+        in += N_BLOCK;
+        out += N_BLOCK;
+    }
+    return EXIT_SUCCESS;
+}
+
+#endif
+
+#if defined( AES_DEC_PREKEYED )
+
+/*  Decrypt a single block of 16 bytes */
+
+return_type aes_decrypt( const uint8_t in[N_BLOCK], uint8_t out[N_BLOCK], const aes_context ctx[1] )
+{
+    if( ctx->rnd )
+    {
+        uint8_t s1[N_BLOCK], r;
+        copy_and_key( s1, in, ctx->ksch + ctx->rnd * N_BLOCK );
+        inv_shift_sub_rows( s1 );
+
+        for( r = ctx->rnd ; --r ; )
+#if defined( VERSION_1 )
+        {
+            add_round_key( s1, ctx->ksch + r * N_BLOCK );
+            inv_mix_sub_columns( s1 );
+        }
+#else
+        {   uint8_t s2[N_BLOCK];
+            copy_and_key( s2, s1, ctx->ksch + r * N_BLOCK );
+            inv_mix_sub_columns( s1, s2 );
+        }
+#endif
+        copy_and_key( out, s1, ctx->ksch );
+    }
+    else
+        return -1;
+    return 0;
+}
+
+/* CBC decrypt a number of blocks (input and return an IV) */
+
+return_type aes_cbc_decrypt( const uint8_t *in, uint8_t *out,
+                         int32_t n_block, uint8_t iv[N_BLOCK], const aes_context ctx[1] )
+{   
+    while(n_block--)
+    {   uint8_t tmp[N_BLOCK];
+        
+        //memcpy(tmp, in, N_BLOCK);
+        block_copy(tmp, in);
+        if(aes_decrypt(in, out, ctx) != EXIT_SUCCESS)
+            return EXIT_FAILURE;
+        xor_block(out, iv);
+        //memcpy(iv, tmp, N_BLOCK);
+        block_copy(iv, tmp);
+        in += N_BLOCK;
+        out += N_BLOCK;
+    }
+    return EXIT_SUCCESS;
+}
+
+#endif
+
+#if defined( AES_ENC_128_OTFK )
+
+/*  The 'on the fly' encryption key update for for 128 bit keys */
+
+static void update_encrypt_key_128( uint8_t k[N_BLOCK], uint8_t *rc )
+{   uint8_t cc;
+
+    k[0] ^= s_box(k[13]) ^ *rc;
+    k[1] ^= s_box(k[14]);
+    k[2] ^= s_box(k[15]);
+    k[3] ^= s_box(k[12]);
+    *rc = f2( *rc );
+
+    for(cc = 4; cc < 16; cc += 4 )
+    {
+        k[cc + 0] ^= k[cc - 4];
+        k[cc + 1] ^= k[cc - 3];
+        k[cc + 2] ^= k[cc - 2];
+        k[cc + 3] ^= k[cc - 1];
+    }
+}
+
+/*  Encrypt a single block of 16 bytes with 'on the fly' 128 bit keying */
+
+void aes_encrypt_128( const uint8_t in[N_BLOCK], uint8_t out[N_BLOCK],
+                     const uint8_t key[N_BLOCK], uint8_t o_key[N_BLOCK] )
+{   uint8_t s1[N_BLOCK], r, rc = 1;
+
+    if(o_key != key)
+        block_copy( o_key, key );
+    copy_and_key( s1, in, o_key );
+
+    for( r = 1 ; r < 10 ; ++r )
+#if defined( VERSION_1 )
+    {
+        mix_sub_columns( s1 );
+        update_encrypt_key_128( o_key, &rc );
+        add_round_key( s1, o_key );
+    }
+#else
+    {   uint8_t s2[N_BLOCK];
+        mix_sub_columns( s2, s1 );
+        update_encrypt_key_128( o_key, &rc );
+        copy_and_key( s1, s2, o_key );
+    }
+#endif
+
+    shift_sub_rows( s1 );
+    update_encrypt_key_128( o_key, &rc );
+    copy_and_key( out, s1, o_key );
+}
+
+#endif
+
+#if defined( AES_DEC_128_OTFK )
+
+/*  The 'on the fly' decryption key update for for 128 bit keys */
+
+static void update_decrypt_key_128( uint8_t k[N_BLOCK], uint8_t *rc )
+{   uint8_t cc;
+
+    for( cc = 12; cc > 0; cc -= 4 )
+    {
+        k[cc + 0] ^= k[cc - 4];
+        k[cc + 1] ^= k[cc - 3];
+        k[cc + 2] ^= k[cc - 2];
+        k[cc + 3] ^= k[cc - 1];
+    }
+    *rc = d2(*rc);
+    k[0] ^= s_box(k[13]) ^ *rc;
+    k[1] ^= s_box(k[14]);
+    k[2] ^= s_box(k[15]);
+    k[3] ^= s_box(k[12]);
+}
+
+/*  Decrypt a single block of 16 bytes with 'on the fly' 128 bit keying */
+
+void aes_decrypt_128( const uint8_t in[N_BLOCK], uint8_t out[N_BLOCK],
+                      const uint8_t key[N_BLOCK], uint8_t o_key[N_BLOCK] )
+{
+    uint8_t s1[N_BLOCK], r, rc = 0x6c;
+    if(o_key != key)
+        block_copy( o_key, key );
+
+    copy_and_key( s1, in, o_key );
+    inv_shift_sub_rows( s1 );
+
+    for( r = 10 ; --r ; )
+#if defined( VERSION_1 )
+    {
+        update_decrypt_key_128( o_key, &rc );
+        add_round_key( s1, o_key );
+        inv_mix_sub_columns( s1 );
+    }
+#else
+    {   uint8_t s2[N_BLOCK];
+        update_decrypt_key_128( o_key, &rc );
+        copy_and_key( s2, s1, o_key );
+        inv_mix_sub_columns( s1, s2 );
+    }
+#endif
+    update_decrypt_key_128( o_key, &rc );
+    copy_and_key( out, s1, o_key );
+}
+
+#endif
+
+#if defined( AES_ENC_256_OTFK )
+
+/*  The 'on the fly' encryption key update for for 256 bit keys */
+
+static void update_encrypt_key_256( uint8_t k[2 * N_BLOCK], uint8_t *rc )
+{   uint8_t cc;
+
+    k[0] ^= s_box(k[29]) ^ *rc;
+    k[1] ^= s_box(k[30]);
+    k[2] ^= s_box(k[31]);
+    k[3] ^= s_box(k[28]);
+    *rc = f2( *rc );
+
+    for(cc = 4; cc < 16; cc += 4)
+    {
+        k[cc + 0] ^= k[cc - 4];
+        k[cc + 1] ^= k[cc - 3];
+        k[cc + 2] ^= k[cc - 2];
+        k[cc + 3] ^= k[cc - 1];
+    }
+
+    k[16] ^= s_box(k[12]);
+    k[17] ^= s_box(k[13]);
+    k[18] ^= s_box(k[14]);
+    k[19] ^= s_box(k[15]);
+
+    for( cc = 20; cc < 32; cc += 4 )
+    {
+        k[cc + 0] ^= k[cc - 4];
+        k[cc + 1] ^= k[cc - 3];
+        k[cc + 2] ^= k[cc - 2];
+        k[cc + 3] ^= k[cc - 1];
+    }
+}
+
+/*  Encrypt a single block of 16 bytes with 'on the fly' 256 bit keying */
+
+void aes_encrypt_256( const uint8_t in[N_BLOCK], uint8_t out[N_BLOCK],
+                      const uint8_t key[2 * N_BLOCK], uint8_t o_key[2 * N_BLOCK] )
+{
+    uint8_t s1[N_BLOCK], r, rc = 1;
+    if(o_key != key)
+    {
+        block_copy( o_key, key );
+        block_copy( o_key + 16, key + 16 );
+    }
+    copy_and_key( s1, in, o_key );
+
+    for( r = 1 ; r < 14 ; ++r )
+#if defined( VERSION_1 )
+    {
+        mix_sub_columns(s1);
+        if( r & 1 )
+            add_round_key( s1, o_key + 16 );
+        else
+        {
+            update_encrypt_key_256( o_key, &rc );
+            add_round_key( s1, o_key );
+        }
+    }
+#else
+    {   uint8_t s2[N_BLOCK];
+        mix_sub_columns( s2, s1 );
+        if( r & 1 )
+            copy_and_key( s1, s2, o_key + 16 );
+        else
+        {
+            update_encrypt_key_256( o_key, &rc );
+            copy_and_key( s1, s2, o_key );
+        }
+    }
+#endif
+
+    shift_sub_rows( s1 );
+    update_encrypt_key_256( o_key, &rc );
+    copy_and_key( out, s1, o_key );
+}
+
+#endif
+
+#if defined( AES_DEC_256_OTFK )
+
+/*  The 'on the fly' encryption key update for for 256 bit keys */
+
+static void update_decrypt_key_256( uint8_t k[2 * N_BLOCK], uint8_t *rc )
+{   uint8_t cc;
+
+    for(cc = 28; cc > 16; cc -= 4)
+    {
+        k[cc + 0] ^= k[cc - 4];
+        k[cc + 1] ^= k[cc - 3];
+        k[cc + 2] ^= k[cc - 2];
+        k[cc + 3] ^= k[cc - 1];
+    }
+
+    k[16] ^= s_box(k[12]);
+    k[17] ^= s_box(k[13]);
+    k[18] ^= s_box(k[14]);
+    k[19] ^= s_box(k[15]);
+
+    for(cc = 12; cc > 0; cc -= 4)
+    {
+        k[cc + 0] ^= k[cc - 4];
+        k[cc + 1] ^= k[cc - 3];
+        k[cc + 2] ^= k[cc - 2];
+        k[cc + 3] ^= k[cc - 1];
+    }
+
+    *rc = d2(*rc);
+    k[0] ^= s_box(k[29]) ^ *rc;
+    k[1] ^= s_box(k[30]);
+    k[2] ^= s_box(k[31]);
+    k[3] ^= s_box(k[28]);
+}
+
+/*  Decrypt a single block of 16 bytes with 'on the fly'
+    256 bit keying
+*/
+void aes_decrypt_256( const uint8_t in[N_BLOCK], uint8_t out[N_BLOCK],
+                      const uint8_t key[2 * N_BLOCK], uint8_t o_key[2 * N_BLOCK] )
+{
+    uint8_t s1[N_BLOCK], r, rc = 0x80;
+
+    if(o_key != key)
+    {
+        block_copy( o_key, key );
+        block_copy( o_key + 16, key + 16 );
+    }
+
+    copy_and_key( s1, in, o_key );
+    inv_shift_sub_rows( s1 );
+
+    for( r = 14 ; --r ; )
+#if defined( VERSION_1 )
+    {
+        if( ( r & 1 ) )
+        {
+            update_decrypt_key_256( o_key, &rc );
+            add_round_key( s1, o_key + 16 );
+        }
+        else
+            add_round_key( s1, o_key );
+        inv_mix_sub_columns( s1 );
+    }
+#else
+    {   uint8_t s2[N_BLOCK];
+        if( ( r & 1 ) )
+        {
+            update_decrypt_key_256( o_key, &rc );
+            copy_and_key( s2, s1, o_key + 16 );
+        }
+        else
+            copy_and_key( s2, s1, o_key );
+        inv_mix_sub_columns( s1, s2 );
+    }
+#endif
+    copy_and_key( out, s1, o_key );
+}
+
+#endif