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mirror of git://git.gnupg.org/gnupg.git synced 2024-12-23 10:29:58 +01:00
2004-07-20 11:48:09 +00:00

579 lines
16 KiB
C

/*
---------------------------------------------------------------------------
Copyright (c) 2003, Dr Brian Gladman, Worcester, UK. All rights reserved.
LICENSE TERMS
The free distribution and use of this software in both source and binary
form is allowed (with or without changes) provided that:
1. distributions of this source code include the above copyright
notice, this list of conditions and the following disclaimer;
2. distributions in binary form include the above copyright
notice, this list of conditions and the following disclaimer
in the documentation and/or other associated materials;
3. the copyright holder's name is not used to endorse products
built using this software without specific written permission.
ALTERNATIVELY, provided that this notice is retained in full, this product
may be distributed under the terms of the GNU General Public License (GPL),
in which case the provisions of the GPL apply INSTEAD OF those given above.
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 30/06/2004
*/
#include "aesopt.h"
#include "aestab.h"
#ifdef USE_VIA_ACE
#include "via_ace.h"
#endif
#if defined(__cplusplus)
extern "C"
{
#endif
/* Initialise the key schedule from the user supplied key. The key
length can be specified in bytes, with legal values of 16, 24
and 32, or in bits, with legal values of 128, 192 and 256. These
values correspond with Nk values of 4, 6 and 8 respectively.
The following macros implement a single cycle in the key
schedule generation process. The number of cycles needed
for each cx->n_col and nk value is:
nk = 4 5 6 7 8
------------------------------
cx->n_col = 4 10 9 8 7 7
cx->n_col = 5 14 11 10 9 9
cx->n_col = 6 19 15 12 11 11
cx->n_col = 7 21 19 16 13 14
cx->n_col = 8 29 23 19 17 14
*/
#if defined(ENCRYPTION_KEY_SCHEDULE)
#if defined(AES_128) || defined(AES_VAR)
#define ke4(k,i) \
{ k[4*(i)+4] = ss[0] ^= ls_box(ss[3],3) ^ t_use(r,c)[i]; \
k[4*(i)+5] = ss[1] ^= ss[0]; \
k[4*(i)+6] = ss[2] ^= ss[1]; \
k[4*(i)+7] = ss[3] ^= ss[2]; \
}
aes_rval aes_encrypt_key128(const unsigned char *key, aes_encrypt_ctx cx[1])
{ aes_32t ss[4];
cx->ks[0] = ss[0] = word_in(key, 0);
cx->ks[1] = ss[1] = word_in(key, 1);
cx->ks[2] = ss[2] = word_in(key, 2);
cx->ks[3] = ss[3] = word_in(key, 3);
#if ENC_UNROLL == NONE
{ aes_32t i;
for(i = 0; i < 9; ++i)
ke4(cx->ks, i);
}
#else
ke4(cx->ks, 0); ke4(cx->ks, 1);
ke4(cx->ks, 2); ke4(cx->ks, 3);
ke4(cx->ks, 4); ke4(cx->ks, 5);
ke4(cx->ks, 6); ke4(cx->ks, 7);
ke4(cx->ks, 8);
#endif
ke4(cx->ks, 9);
cx->inf.l = 0;
cx->inf.b[0] = 10 * 16;
#ifdef USE_VIA_ACE
if(via_ace_available())
cx->inf.b[1] = 0xff;
#endif
#if defined( AES_ERR_CHK )
return aes_good;
#endif
}
#endif
#if defined(AES_192) || defined(AES_VAR)
#define kef6(k,i) \
{ k[6*(i)+ 6] = ss[0] ^= ls_box(ss[5],3) ^ t_use(r,c)[i]; \
k[6*(i)+ 7] = ss[1] ^= ss[0]; \
k[6*(i)+ 8] = ss[2] ^= ss[1]; \
k[6*(i)+ 9] = ss[3] ^= ss[2]; \
}
#define ke6(k,i) \
{ kef6(k,i); \
k[6*(i)+10] = ss[4] ^= ss[3]; \
k[6*(i)+11] = ss[5] ^= ss[4]; \
}
aes_rval aes_encrypt_key192(const unsigned char *key, aes_encrypt_ctx cx[1])
{ aes_32t ss[6];
cx->ks[0] = ss[0] = word_in(key, 0);
cx->ks[1] = ss[1] = word_in(key, 1);
cx->ks[2] = ss[2] = word_in(key, 2);
cx->ks[3] = ss[3] = word_in(key, 3);
cx->ks[4] = ss[4] = word_in(key, 4);
cx->ks[5] = ss[5] = word_in(key, 5);
#if ENC_UNROLL == NONE
{ aes_32t i;
for(i = 0; i < 7; ++i)
ke6(cx->ks, i);
}
#else
ke6(cx->ks, 0); ke6(cx->ks, 1);
ke6(cx->ks, 2); ke6(cx->ks, 3);
ke6(cx->ks, 4); ke6(cx->ks, 5);
ke6(cx->ks, 6);
#endif
kef6(cx->ks, 7);
cx->inf.l = 0;
cx->inf.b[0] = 12 * 16;
#ifdef USE_VIA_ACE
if(via_ace_available())
cx->inf.b[1] = 0xff;
#endif
#if defined( AES_ERR_CHK )
return aes_good;
#endif
}
#endif
#if defined(AES_256) || defined(AES_VAR)
#define kef8(k,i) \
{ k[8*(i)+ 8] = ss[0] ^= ls_box(ss[7],3) ^ t_use(r,c)[i]; \
k[8*(i)+ 9] = ss[1] ^= ss[0]; \
k[8*(i)+10] = ss[2] ^= ss[1]; \
k[8*(i)+11] = ss[3] ^= ss[2]; \
}
#define ke8(k,i) \
{ kef8(k,i); \
k[8*(i)+12] = ss[4] ^= ls_box(ss[3],0); \
k[8*(i)+13] = ss[5] ^= ss[4]; \
k[8*(i)+14] = ss[6] ^= ss[5]; \
k[8*(i)+15] = ss[7] ^= ss[6]; \
}
aes_rval aes_encrypt_key256(const unsigned char *key, aes_encrypt_ctx cx[1])
{ aes_32t ss[8];
cx->ks[0] = ss[0] = word_in(key, 0);
cx->ks[1] = ss[1] = word_in(key, 1);
cx->ks[2] = ss[2] = word_in(key, 2);
cx->ks[3] = ss[3] = word_in(key, 3);
cx->ks[4] = ss[4] = word_in(key, 4);
cx->ks[5] = ss[5] = word_in(key, 5);
cx->ks[6] = ss[6] = word_in(key, 6);
cx->ks[7] = ss[7] = word_in(key, 7);
#if ENC_UNROLL == NONE
{ aes_32t i;
for(i = 0; i < 6; ++i)
ke8(cx->ks, i);
}
#else
ke8(cx->ks, 0); ke8(cx->ks, 1);
ke8(cx->ks, 2); ke8(cx->ks, 3);
ke8(cx->ks, 4); ke8(cx->ks, 5);
#endif
kef8(cx->ks, 6);
cx->inf.l = 0;
cx->inf.b[0] = 14 * 16;
#ifdef USE_VIA_ACE
if(via_ace_available())
cx->inf.b[1] = 0xff;
#endif
#if defined( AES_ERR_CHK )
return aes_good;
#endif
}
#endif
#if defined(AES_VAR)
aes_rval aes_encrypt_key(const unsigned char *key, int key_len, aes_encrypt_ctx cx[1])
{
switch(key_len)
{
#if defined( AES_ERR_CHK )
case 16: case 128: return aes_encrypt_key128(key, cx);
case 24: case 192: return aes_encrypt_key192(key, cx);
case 32: case 256: return aes_encrypt_key256(key, cx);
default: return aes_error;
#else
case 16: case 128: aes_encrypt_key128(key, cx); return;
case 24: case 192: aes_encrypt_key192(key, cx); return;
case 32: case 256: aes_encrypt_key256(key, cx); return;
#endif
}
}
#endif
#endif
#if defined(DECRYPTION_KEY_SCHEDULE)
/* this is used to store the decryption round keys */
/* in forward or reverse order */
#ifdef AES_REV_DKS
#define v(n,i) ((n) - (i) + 2 * ((i) & 3))
#else
#define v(n,i) (i)
#endif
#if DEC_ROUND == NO_TABLES
#define ff(x) (x)
#else
#define ff(x) inv_mcol(x)
#if defined( dec_imvars )
#define d_vars dec_imvars
#endif
#endif
#if defined(AES_128) || defined(AES_VAR)
#define k4e(k,i) \
{ k[v(40,(4*(i))+4)] = ss[0] ^= ls_box(ss[3],3) ^ t_use(r,c)[i]; \
k[v(40,(4*(i))+5)] = ss[1] ^= ss[0]; \
k[v(40,(4*(i))+6)] = ss[2] ^= ss[1]; \
k[v(40,(4*(i))+7)] = ss[3] ^= ss[2]; \
}
#if 1
#define kdf4(k,i) \
{ ss[0] = ss[0] ^ ss[2] ^ ss[1] ^ ss[3]; \
ss[1] = ss[1] ^ ss[3]; \
ss[2] = ss[2] ^ ss[3]; \
ss[4] = ls_box(ss[(i+3) % 4], 3) ^ t_use(r,c)[i]; \
ss[i % 4] ^= ss[4]; \
ss[4] ^= k[v(40,(4*(i)))]; k[v(40,(4*(i))+4)] = ff(ss[4]); \
ss[4] ^= k[v(40,(4*(i))+1)]; k[v(40,(4*(i))+5)] = ff(ss[4]); \
ss[4] ^= k[v(40,(4*(i))+2)]; k[v(40,(4*(i))+6)] = ff(ss[4]); \
ss[4] ^= k[v(40,(4*(i))+3)]; k[v(40,(4*(i))+7)] = ff(ss[4]); \
}
#define kd4(k,i) \
{ ss[4] = ls_box(ss[(i+3) % 4], 3) ^ t_use(r,c)[i]; \
ss[i % 4] ^= ss[4]; ss[4] = ff(ss[4]); \
k[v(40,(4*(i))+4)] = ss[4] ^= k[v(40,(4*(i)))]; \
k[v(40,(4*(i))+5)] = ss[4] ^= k[v(40,(4*(i))+1)]; \
k[v(40,(4*(i))+6)] = ss[4] ^= k[v(40,(4*(i))+2)]; \
k[v(40,(4*(i))+7)] = ss[4] ^= k[v(40,(4*(i))+3)]; \
}
#define kdl4(k,i) \
{ ss[4] = ls_box(ss[(i+3) % 4], 3) ^ t_use(r,c)[i]; ss[i % 4] ^= ss[4]; \
k[v(40,(4*(i))+4)] = (ss[0] ^= ss[1]) ^ ss[2] ^ ss[3]; \
k[v(40,(4*(i))+5)] = ss[1] ^ ss[3]; \
k[v(40,(4*(i))+6)] = ss[0]; \
k[v(40,(4*(i))+7)] = ss[1]; \
}
#else
#define kdf4(k,i) \
{ ss[0] ^= ls_box(ss[3],3) ^ t_use(r,c)[i]; k[v(40,(4*(i))+ 4)] = ff(ss[0]); \
ss[1] ^= ss[0]; k[v(40,(4*(i))+ 5)] = ff(ss[1]); \
ss[2] ^= ss[1]; k[v(40,(4*(i))+ 6)] = ff(ss[2]); \
ss[3] ^= ss[2]; k[v(40,(4*(i))+ 7)] = ff(ss[3]); \
}
#define kd4(k,i) \
{ ss[4] = ls_box(ss[3],3) ^ t_use(r,c)[i]; \
ss[0] ^= ss[4]; ss[4] = ff(ss[4]); k[v(40,(4*(i))+ 4)] = ss[4] ^= k[v(40,(4*(i)))]; \
ss[1] ^= ss[0]; k[v(40,(4*(i))+ 5)] = ss[4] ^= k[v(40,(4*(i))+ 1)]; \
ss[2] ^= ss[1]; k[v(40,(4*(i))+ 6)] = ss[4] ^= k[v(40,(4*(i))+ 2)]; \
ss[3] ^= ss[2]; k[v(40,(4*(i))+ 7)] = ss[4] ^= k[v(40,(4*(i))+ 3)]; \
}
#define kdl4(k,i) \
{ ss[0] ^= ls_box(ss[3],3) ^ t_use(r,c)[i]; k[v(40,(4*(i))+ 4)] = ss[0]; \
ss[1] ^= ss[0]; k[v(40,(4*(i))+ 5)] = ss[1]; \
ss[2] ^= ss[1]; k[v(40,(4*(i))+ 6)] = ss[2]; \
ss[3] ^= ss[2]; k[v(40,(4*(i))+ 7)] = ss[3]; \
}
#endif
aes_rval aes_decrypt_key128(const unsigned char *key, aes_decrypt_ctx cx[1])
{ aes_32t ss[5];
#if defined( d_vars )
d_vars;
#endif
cx->ks[v(40,(0))] = ss[0] = word_in(key, 0);
cx->ks[v(40,(1))] = ss[1] = word_in(key, 1);
cx->ks[v(40,(2))] = ss[2] = word_in(key, 2);
cx->ks[v(40,(3))] = ss[3] = word_in(key, 3);
#if DEC_UNROLL == NONE
{ aes_32t i;
for(i = 0; i < 10; ++i)
k4e(cx->ks, i);
#if !(DEC_ROUND == NO_TABLES)
for(i = N_COLS; i < 10 * N_COLS; ++i)
cx->ks[i] = inv_mcol(cx->ks[i]);
#endif
}
#else
kdf4(cx->ks, 0); kd4(cx->ks, 1);
kd4(cx->ks, 2); kd4(cx->ks, 3);
kd4(cx->ks, 4); kd4(cx->ks, 5);
kd4(cx->ks, 6); kd4(cx->ks, 7);
kd4(cx->ks, 8); kdl4(cx->ks, 9);
#endif
cx->inf.l = 0;
cx->inf.b[0] = 10 * 16;
#ifdef USE_VIA_ACE
if(via_ace_available())
cx->inf.b[1] = 0xff;
#endif
#if defined( AES_ERR_CHK )
return aes_good;
#endif
}
#endif
#if defined(AES_192) || defined(AES_VAR)
#define k6ef(k,i) \
{ k[v(48,(6*(i))+ 6)] = ss[0] ^= ls_box(ss[5],3) ^ t_use(r,c)[i]; \
k[v(48,(6*(i))+ 7)] = ss[1] ^= ss[0]; \
k[v(48,(6*(i))+ 8)] = ss[2] ^= ss[1]; \
k[v(48,(6*(i))+ 9)] = ss[3] ^= ss[2]; \
}
#define k6e(k,i) \
{ k6ef(k,i); \
k[v(48,(6*(i))+10)] = ss[4] ^= ss[3]; \
k[v(48,(6*(i))+11)] = ss[5] ^= ss[4]; \
}
#define kdf6(k,i) \
{ ss[0] ^= ls_box(ss[5],3) ^ t_use(r,c)[i]; k[v(48,(6*(i))+ 6)] = ff(ss[0]); \
ss[1] ^= ss[0]; k[v(48,(6*(i))+ 7)] = ff(ss[1]); \
ss[2] ^= ss[1]; k[v(48,(6*(i))+ 8)] = ff(ss[2]); \
ss[3] ^= ss[2]; k[v(48,(6*(i))+ 9)] = ff(ss[3]); \
ss[4] ^= ss[3]; k[v(48,(6*(i))+10)] = ff(ss[4]); \
ss[5] ^= ss[4]; k[v(48,(6*(i))+11)] = ff(ss[5]); \
}
#define kd6(k,i) \
{ ss[6] = ls_box(ss[5],3) ^ t_use(r,c)[i]; \
ss[0] ^= ss[6]; ss[6] = ff(ss[6]); k[v(48,(6*(i))+ 6)] = ss[6] ^= k[v(48,(6*(i)))]; \
ss[1] ^= ss[0]; k[v(48,(6*(i))+ 7)] = ss[6] ^= k[v(48,(6*(i))+ 1)]; \
ss[2] ^= ss[1]; k[v(48,(6*(i))+ 8)] = ss[6] ^= k[v(48,(6*(i))+ 2)]; \
ss[3] ^= ss[2]; k[v(48,(6*(i))+ 9)] = ss[6] ^= k[v(48,(6*(i))+ 3)]; \
ss[4] ^= ss[3]; k[v(48,(6*(i))+10)] = ss[6] ^= k[v(48,(6*(i))+ 4)]; \
ss[5] ^= ss[4]; k[v(48,(6*(i))+11)] = ss[6] ^= k[v(48,(6*(i))+ 5)]; \
}
#define kdl6(k,i) \
{ ss[0] ^= ls_box(ss[5],3) ^ t_use(r,c)[i]; k[v(48,(6*(i))+ 6)] = ss[0]; \
ss[1] ^= ss[0]; k[v(48,(6*(i))+ 7)] = ss[1]; \
ss[2] ^= ss[1]; k[v(48,(6*(i))+ 8)] = ss[2]; \
ss[3] ^= ss[2]; k[v(48,(6*(i))+ 9)] = ss[3]; \
}
aes_rval aes_decrypt_key192(const unsigned char *key, aes_decrypt_ctx cx[1])
{ aes_32t ss[7];
#if defined( d_vars )
d_vars;
#endif
cx->ks[v(48,(0))] = ss[0] = word_in(key, 0);
cx->ks[v(48,(1))] = ss[1] = word_in(key, 1);
cx->ks[v(48,(2))] = ss[2] = word_in(key, 2);
cx->ks[v(48,(3))] = ss[3] = word_in(key, 3);
#if DEC_UNROLL == NONE
cx->ks[v(48,(4))] = ss[4] = word_in(key, 4);
cx->ks[v(48,(5))] = ss[5] = word_in(key, 5);
{ aes_32t i;
for(i = 0; i < 7; ++i)
k6e(cx->ks, i);
k6ef(cx->ks, 7);
#if !(DEC_ROUND == NO_TABLES)
for(i = N_COLS; i < 12 * N_COLS; ++i)
cx->ks[i] = inv_mcol(cx->ks[i]);
#endif
}
#else
cx->ks[v(48,(4))] = ff(ss[4] = word_in(key, 4));
cx->ks[v(48,(5))] = ff(ss[5] = word_in(key, 5));
kdf6(cx->ks, 0); kd6(cx->ks, 1);
kd6(cx->ks, 2); kd6(cx->ks, 3);
kd6(cx->ks, 4); kd6(cx->ks, 5);
kd6(cx->ks, 6); kdl6(cx->ks, 7);
#endif
cx->inf.l = 0;
cx->inf.b[0] = 12 * 16;
#ifdef USE_VIA_ACE
if(via_ace_available())
cx->inf.b[1] = 0xff;
#endif
#if defined( AES_ERR_CHK )
return aes_good;
#endif
}
#endif
#if defined(AES_256) || defined(AES_VAR)
#define k8ef(k,i) \
{ k[v(56,(8*(i))+ 8)] = ss[0] ^= ls_box(ss[7],3) ^ t_use(r,c)[i]; \
k[v(56,(8*(i))+ 9)] = ss[1] ^= ss[0]; \
k[v(56,(8*(i))+10)] = ss[2] ^= ss[1]; \
k[v(56,(8*(i))+11)] = ss[3] ^= ss[2]; \
}
#define k8e(k,i) \
{ k8ef(k,i); \
k[v(56,(8*(i))+12)] = ss[4] ^= ls_box(ss[3],0); \
k[v(56,(8*(i))+13)] = ss[5] ^= ss[4]; \
k[v(56,(8*(i))+14)] = ss[6] ^= ss[5]; \
k[v(56,(8*(i))+15)] = ss[7] ^= ss[6]; \
}
#define kdf8(k,i) \
{ ss[0] ^= ls_box(ss[7],3) ^ t_use(r,c)[i]; k[v(56,(8*(i))+ 8)] = ff(ss[0]); \
ss[1] ^= ss[0]; k[v(56,(8*(i))+ 9)] = ff(ss[1]); \
ss[2] ^= ss[1]; k[v(56,(8*(i))+10)] = ff(ss[2]); \
ss[3] ^= ss[2]; k[v(56,(8*(i))+11)] = ff(ss[3]); \
ss[4] ^= ls_box(ss[3],0); k[v(56,(8*(i))+12)] = ff(ss[4]); \
ss[5] ^= ss[4]; k[v(56,(8*(i))+13)] = ff(ss[5]); \
ss[6] ^= ss[5]; k[v(56,(8*(i))+14)] = ff(ss[6]); \
ss[7] ^= ss[6]; k[v(56,(8*(i))+15)] = ff(ss[7]); \
}
#define kd8(k,i) \
{ ss[8] = ls_box(ss[7],3) ^ t_use(r,c)[i]; \
ss[0] ^= ss[8]; ss[8] = ff(ss[8]); k[v(56,(8*(i))+ 8)] = ss[8] ^= k[v(56,(8*(i)))]; \
ss[1] ^= ss[0]; k[v(56,(8*(i))+ 9)] = ss[8] ^= k[v(56,(8*(i))+ 1)]; \
ss[2] ^= ss[1]; k[v(56,(8*(i))+10)] = ss[8] ^= k[v(56,(8*(i))+ 2)]; \
ss[3] ^= ss[2]; k[v(56,(8*(i))+11)] = ss[8] ^= k[v(56,(8*(i))+ 3)]; \
ss[8] = ls_box(ss[3],0); \
ss[4] ^= ss[8]; ss[8] = ff(ss[8]); k[v(56,(8*(i))+12)] = ss[8] ^= k[v(56,(8*(i))+ 4)]; \
ss[5] ^= ss[4]; k[v(56,(8*(i))+13)] = ss[8] ^= k[v(56,(8*(i))+ 5)]; \
ss[6] ^= ss[5]; k[v(56,(8*(i))+14)] = ss[8] ^= k[v(56,(8*(i))+ 6)]; \
ss[7] ^= ss[6]; k[v(56,(8*(i))+15)] = ss[8] ^= k[v(56,(8*(i))+ 7)]; \
}
#define kdl8(k,i) \
{ ss[0] ^= ls_box(ss[7],3) ^ t_use(r,c)[i]; k[v(56,(8*(i))+ 8)] = ss[0]; \
ss[1] ^= ss[0]; k[v(56,(8*(i))+ 9)] = ss[1]; \
ss[2] ^= ss[1]; k[v(56,(8*(i))+10)] = ss[2]; \
ss[3] ^= ss[2]; k[v(56,(8*(i))+11)] = ss[3]; \
}
aes_rval aes_decrypt_key256(const unsigned char *key, aes_decrypt_ctx cx[1])
{ aes_32t ss[9];
#if defined( d_vars )
d_vars;
#endif
cx->ks[v(56,(0))] = ss[0] = word_in(key, 0);
cx->ks[v(56,(1))] = ss[1] = word_in(key, 1);
cx->ks[v(56,(2))] = ss[2] = word_in(key, 2);
cx->ks[v(56,(3))] = ss[3] = word_in(key, 3);
#if DEC_UNROLL == NONE
cx->ks[v(56,(4))] = ss[4] = word_in(key, 4);
cx->ks[v(56,(5))] = ss[5] = word_in(key, 5);
cx->ks[v(56,(6))] = ss[6] = word_in(key, 6);
cx->ks[v(56,(7))] = ss[7] = word_in(key, 7);
{ aes_32t i;
for(i = 0; i < 6; ++i)
k8e(cx->ks, i);
k8ef(cx->ks, 6);
#if !(DEC_ROUND == NO_TABLES)
for(i = N_COLS; i < 14 * N_COLS; ++i)
cx->ks[i] = inv_mcol(cx->ks[i]);
#endif
}
#else
cx->ks[v(56,(4))] = ff(ss[4] = word_in(key, 4));
cx->ks[v(56,(5))] = ff(ss[5] = word_in(key, 5));
cx->ks[v(56,(6))] = ff(ss[6] = word_in(key, 6));
cx->ks[v(56,(7))] = ff(ss[7] = word_in(key, 7));
kdf8(cx->ks, 0); kd8(cx->ks, 1);
kd8(cx->ks, 2); kd8(cx->ks, 3);
kd8(cx->ks, 4); kd8(cx->ks, 5);
kdl8(cx->ks, 6);
#endif
cx->inf.l = 0;
cx->inf.b[0] = 14 * 16;
#ifdef USE_VIA_ACE
if(via_ace_available())
cx->inf.b[1] = 0xff;
#endif
#if defined( AES_ERR_CHK )
return aes_good;
#endif
}
#endif
#if defined(AES_VAR)
aes_rval aes_decrypt_key(const unsigned char *key, int key_len, aes_decrypt_ctx cx[1])
{
switch(key_len)
{
#if defined( AES_ERR_CHK )
case 16: case 128: return aes_decrypt_key128(key, cx);
case 24: case 192: return aes_decrypt_key192(key, cx);
case 32: case 256: return aes_decrypt_key256(key, cx);
default: return aes_error;
#else
case 16: case 128: aes_decrypt_key128(key, cx); return;
case 24: case 192: aes_decrypt_key192(key, cx); return;
case 32: case 256: aes_decrypt_key256(key, cx); return;
#endif
}
}
#endif
#endif
#if defined(__cplusplus)
}
#endif