纯C：AES256

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aes256.h

#ifndef _AES256_H_
#define _AES256_H_
#include <stdio.h>
#include <string.h>
#include <stdlib.h>

#ifndef uint8_t
#define uint8_t unsigned char
#endif

#define AES_BLOCK_SIZE 16

#ifdef __cplusplus
extern "C" {
#endif

typedef struct {
uint8_t key[32];
uint8_t enckey[32];
uint8_t deckey[32];
} aes256_context;

void aes256_init(aes256_context *, uint8_t * /* key */);
void aes256_done(aes256_context *);
void aes256_encrypt(aes256_context *, uint8_t * /* plaintext */);
void aes256_decrypt(aes256_context *, uint8_t *, uint8_t */* cipertext */);
void aes256_encrypt_cbc(aes256_context *, uint8_t *, int inLen, uint8_t *, uint8_t *);
void aes256_decrypt_cbc(aes256_context *, uint8_t *, int inLen, uint8_t *, uint8_t *);
//AES 固定密钥长度 不填充 返回buff
unsigned char * AES_CBC_PKCS5_Encrypt(unsigned char *, int, unsigned char *, int*);
unsigned char * AES_CBC_PKCS5_Decrypt(unsigned char *, int, unsigned char *, int*);
#ifdef __cplusplus
}
#endif

#define DUMP(s, i, buf, sz) {printf(s); \
for (i = 0; i < (sz);i++) \
printf("%02x ", buf[i]); \
printf("\n");}

#endif

aes256.c

//#ifndef _CRT_SECURE_NO_WARNINGS
//#define _CRT_SECURE_NO_WARNINGS
//#endif
/*
* Byte-oriented AES-256 implementation.
*
* CBC PKCS5Padding with iv

* All lookup tables replaced with 'on the fly' calculations.
*
* Copyright (c) 2007-2009 Ilya O. Levin, http://www.literatecode.com
* Other contributors: Hal Finney
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
* coded by longdw 2015.5.21
* http://www.longdw.com
*/
#include "aes256.h"

#define F(x) (((x)<<1) ^ ((((x)>>7) & 1) * 0x1b))
#define FD(x) (((x) >> 1) ^ (((x) & 1) ? 0x8d : 0))

// #define BACK_TO_TABLES
#ifdef BACK_TO_TABLES

const uint8_t sbox[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
};
const uint8_t sboxinv[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
};

#define rj_sbox(x) sbox[(x)]
#define rj_sbox_inv(x) sboxinv[(x)]

#else /* tableless subroutines */

/* -------------------------------------------------------------------------- */
uint8_t gf_alog(uint8_t x) // calculate anti-logarithm gen 3
{
uint8_t atb = 1, z;

while (x--)
{
z = atb;
atb <<= 1;
if (z & 0x80)
atb ^= 0x1b; atb ^= z;
}

return atb;
} /* gf_alog */

/* -------------------------------------------------------------------------- */
uint8_t gf_log(uint8_t x) // calculate logarithm gen 3
{
uint8_t atb = 1, i = 0, z;

do {
if (atb == x) break;
z = atb; atb <<= 1;
if (z & 0x80)
atb ^= 0x1b; atb ^= z;
} while (++i > 0);

return i;
} /* gf_log */

/* -------------------------------------------------------------------------- */
uint8_t gf_mulinv(uint8_t x) // calculate multiplicative inverse
{
return (x) ? gf_alog(255 - gf_log(x)) : 0;
} /* gf_mulinv */

/* -------------------------------------------------------------------------- */
uint8_t rj_sbox(uint8_t x)
{
uint8_t y, sb;

sb = y = gf_mulinv(x);
y = (y << 1) | (y >> 7); sb ^= y; y = (y << 1) | (y >> 7); sb ^= y;
y = (y << 1) | (y >> 7); sb ^= y; y = (y << 1) | (y >> 7); sb ^= y;

return (sb ^ 0x63);
} /* rj_sbox */

/* -------------------------------------------------------------------------- */
uint8_t rj_sbox_inv(uint8_t x)
{
uint8_t y, sb;

y = x ^ 0x63;
sb = y = (y << 1) | (y >> 7);
y = (y << 2) | (y >> 6); sb ^= y; y = (y << 3) | (y >> 5); sb ^= y;

return gf_mulinv(sb);
} /* rj_sbox_inv */

#endif

/* -------------------------------------------------------------------------- */
uint8_t rj_xtime(uint8_t x)
{
return (x & 0x80) ? ((x << 1) ^ 0x1b) : (x << 1);
} /* rj_xtime */

/* -------------------------------------------------------------------------- */
void aes_subBytes(uint8_t *buf)
{
register uint8_t i = 16;
//register uint8_t i = 32;

while (i--) buf[i] = rj_sbox(buf[i]);
} /* aes_subBytes */

/* -------------------------------------------------------------------------- */
void aes_subBytes_inv(uint8_t *buf)
{
register uint8_t i = 16;
//register uint8_t i = 32;

while (i--) buf[i] = rj_sbox_inv(buf[i]);
} /* aes_subBytes_inv */

/* -------------------------------------------------------------------------- */
void aes_addRoundKey(uint8_t *buf, uint8_t *key)
{
register uint8_t i = 16;
//register uint8_t i = 32;
while (i--) buf[i] ^= key[i];
} /* aes_addRoundKey */

/* -------------------------------------------------------------------------- */
void aes_addRoundKey_cpy(uint8_t *buf, uint8_t *key, uint8_t *cpk)
{
register uint8_t i = 16;
//register uint8_t i = 32;

while (i--) buf[i] ^= (cpk[i] = key[i]), cpk[16 + i] = key[16 + i];
} /* aes_addRoundKey_cpy */

/* -------------------------------------------------------------------------- */
void aes_shiftRows(uint8_t *buf)
{
register uint8_t i, j; /* to make it potentially parallelable :) */

i = buf[1]; buf[1] = buf[5]; buf[5] = buf[9]; buf[9] = buf[13]; buf[13] = i;
i = buf[10]; buf[10] = buf[2]; buf[2] = i;
j = buf[3]; buf[3] = buf[15]; buf[15] = buf[11]; buf[11] = buf[7]; buf[7] = j;
j = buf[14]; buf[14] = buf[6]; buf[6] = j;

} /* aes_shiftRows */

/* -------------------------------------------------------------------------- */
void aes_shiftRows_inv(uint8_t *buf)
{
register uint8_t i, j; /* same as above :) */

i = buf[1]; buf[1] = buf[13]; buf[13] = buf[9]; buf[9] = buf[5]; buf[5] = i;
i = buf[2]; buf[2] = buf[10]; buf[10] = i;
j = buf[3]; buf[3] = buf[7]; buf[7] = buf[11]; buf[11] = buf[15]; buf[15] = j;
j = buf[6]; buf[6] = buf[14]; buf[14] = j;

} /* aes_shiftRows_inv */

/* -------------------------------------------------------------------------- */
void aes_mixColumns(uint8_t *buf)
{
register uint8_t i, a, b, c, d, e;

for (i = 0; i < 16; i += 4)
{
a = buf[i]; b = buf[i + 1]; c = buf[i + 2]; d = buf[i + 3];
e = a ^ b ^ c ^ d;
buf[i] ^= e ^ rj_xtime(a^b); buf[i + 1] ^= e ^ rj_xtime(b^c);
buf[i + 2] ^= e ^ rj_xtime(c^d); buf[i + 3] ^= e ^ rj_xtime(d^a);
}
} /* aes_mixColumns */

/* -------------------------------------------------------------------------- */
void aes_mixColumns_inv(uint8_t *buf)
{
register uint8_t i, a, b, c, d, e, x, y, z;

for (i = 0; i < 16; i += 4)
{
a = buf[i]; b = buf[i + 1]; c = buf[i + 2]; d = buf[i + 3];
e = a ^ b ^ c ^ d;
z = rj_xtime(e);
x = e ^ rj_xtime(rj_xtime(z^a^c)); y = e ^ rj_xtime(rj_xtime(z^b^d));
buf[i] ^= x ^ rj_xtime(a^b); buf[i + 1] ^= y ^ rj_xtime(b^c);
buf[i + 2] ^= x ^ rj_xtime(c^d); buf[i + 3] ^= y ^ rj_xtime(d^a);
}
} /* aes_mixColumns_inv */

/* -------------------------------------------------------------------------- */
void aes_expandEncKey(uint8_t *k, uint8_t *rc)
{
register uint8_t i;

k[0] ^= rj_sbox(k[29]) ^ (*rc);
k[1] ^= rj_sbox(k[30]);
k[2] ^= rj_sbox(k[31]);
k[3] ^= rj_sbox(k[28]);
*rc = F(*rc);

for (i = 4; i < 16; i += 4) k[i] ^= k[i - 4], k[i + 1] ^= k[i - 3],
k[i + 2] ^= k[i - 2], k[i + 3] ^= k[i - 1];
k[16] ^= rj_sbox(k[12]);
k[17] ^= rj_sbox(k[13]);
k[18] ^= rj_sbox(k[14]);
k[19] ^= rj_sbox(k[15]);

for (i = 20; i < 32; i += 4) k[i] ^= k[i - 4], k[i + 1] ^= k[i - 3],
k[i + 2] ^= k[i - 2], k[i + 3] ^= k[i - 1];

} /* aes_expandEncKey */

/* -------------------------------------------------------------------------- */
void aes_expandDecKey(uint8_t *k, uint8_t *rc)
{
uint8_t i;

for (i = 28; i > 16; i -= 4) k[i + 0] ^= k[i - 4], k[i + 1] ^= k[i - 3],
k[i + 2] ^= k[i - 2], k[i + 3] ^= k[i - 1];

k[16] ^= rj_sbox(k[12]);
k[17] ^= rj_sbox(k[13]);
k[18] ^= rj_sbox(k[14]);
k[19] ^= rj_sbox(k[15]);

for (i = 12; i > 0; i -= 4) k[i + 0] ^= k[i - 4], k[i + 1] ^= k[i - 3],
k[i + 2] ^= k[i - 2], k[i + 3] ^= k[i - 1];

*rc = FD(*rc);
k[0] ^= rj_sbox(k[29]) ^ (*rc);
k[1] ^= rj_sbox(k[30]);
k[2] ^= rj_sbox(k[31]);
k[3] ^= rj_sbox(k[28]);
} /* aes_expandDecKey */

/* -------------------------------------------------------------------------- */
void aes256_init(aes256_context *ctx, uint8_t *k)
{
uint8_t rcon = 1;
register uint8_t i;

for (i = 0; i < sizeof(ctx->key); i++) ctx->enckey[i] = ctx->deckey[i] = k[i];
for (i = 8; --i;) aes_expandEncKey(ctx->deckey, &rcon);
} /* aes256_init */

/* -------------------------------------------------------------------------- */
void aes256_done(aes256_context *ctx)
{
register uint8_t i;

for (i = 0; i < sizeof(ctx->key); i++)
ctx->key[i] = ctx->enckey[i] = ctx->deckey[i] = 0;
} /* aes256_done */

/* -------------------------------------------------------------------------- */
void aes256_encrypt(aes256_context *ctx, uint8_t *buf)
{
uint8_t i, rcon;

aes_addRoundKey_cpy(buf, ctx->enckey, ctx->key);
for (i = 1, rcon = 1; i < 14; ++i)
{
aes_subBytes(buf);
aes_shiftRows(buf);
aes_mixColumns(buf);
if (i & 1) aes_addRoundKey(buf, &ctx->key[16]);
else aes_expandEncKey(ctx->key, &rcon), aes_addRoundKey(buf, ctx->key);
}
aes_subBytes(buf);
aes_shiftRows(buf);
aes_expandEncKey(ctx->key, &rcon);
aes_addRoundKey(buf, ctx->key);
} /* aes256_encrypt */

void aes_cbc(uint8_t *buf, uint8_t *iv)
{
register uint8_t i = 16;
//register uint8_t i = 32;
while (i--) buf[i] ^= iv[i];
}/*aes_cbc*/

/* -------------------------------------------------------------------------- */
void aes256_decrypt(aes256_context *ctx, uint8_t *iv, uint8_t *buf)
{
uint8_t i, rcon;

aes_addRoundKey_cpy(buf, ctx->deckey, ctx->key);
aes_shiftRows_inv(buf);
aes_subBytes_inv(buf);

for (i = 14, rcon = 0x80; --i;)
{
if ((i & 1))
{
aes_expandDecKey(ctx->key, &rcon);
aes_addRoundKey(buf, &ctx->key[16]);
}
else aes_addRoundKey(buf, ctx->key);
aes_mixColumns_inv(buf);
aes_shiftRows_inv(buf);
aes_subBytes_inv(buf);
}
aes_addRoundKey(buf, ctx->key);
aes_cbc(buf, iv);
} /* aes256_decrypt */

void aes256_encrypt_cbc(aes256_context *ctx, uint8_t *in,int inLen, uint8_t *iv, uint8_t *out)
{
uint8_t i, j, rcon;
uint8_t buf[16], iv_change[16];
//int size = strlen((char *)in) / 16;
int size = inLen / 16;

for (j = 0; j < size; j++)
{
memcpy(buf, in + j * 16, 16);
if (j == 0)
{
aes_cbc(buf, iv);
aes_addRoundKey_cpy(buf, ctx->enckey, ctx->key);
for (i = 1, rcon = 1; i < 14; ++i)
{
aes_subBytes(buf);
aes_shiftRows(buf);
aes_mixColumns(buf);
if (i & 1) aes_addRoundKey(buf, &ctx->key[16]);
else aes_expandEncKey(ctx->key, &rcon), aes_addRoundKey(buf, ctx->key);
}
aes_subBytes(buf);
aes_shiftRows(buf);
aes_expandEncKey(ctx->key, &rcon);
aes_addRoundKey(buf, ctx->key);

memcpy(out + j * 16, buf, 16);
memcpy(iv_change, buf, 16);
}
else
{
aes_cbc(buf, iv_change);
aes_addRoundKey_cpy(buf, ctx->enckey, ctx->key);
for (i = 1, rcon = 1; i < 14; ++i)
{
aes_subBytes(buf);
aes_shiftRows(buf);
aes_mixColumns(buf);
if (i & 1) aes_addRoundKey(buf, &ctx->key[16]);
else aes_expandEncKey(ctx->key, &rcon), aes_addRoundKey(buf, ctx->key);
}
aes_subBytes(buf);
aes_shiftRows(buf);
aes_expandEncKey(ctx->key, &rcon);
aes_addRoundKey(buf, ctx->key);

memcpy(out + j * 16, buf, 16);
memcpy(iv_change, buf, 16);
}
}
}/*aes256_encrypt_cbc*/

void aes256_decrypt_cbc(aes256_context *ctx, uint8_t *in, int inLen, uint8_t *iv, uint8_t *out)
{
uint8_t i, j, rcon;
uint8_t buf[16], iv_change_1[16], iv_change_2[16];
int size = inLen / 16;
for (j = 0; j < size; j++)
{
memcpy(buf, in + j * 16, 16);
if (j == 0)
{
memcpy(iv_change_1, buf, 16);
aes_addRoundKey_cpy(buf, ctx->deckey, ctx->key);
aes_shiftRows_inv(buf);
aes_subBytes_inv(buf);

for (i = 14, rcon = 0x80; --i;)
{
if ((i & 1))
{
aes_expandDecKey(ctx->key, &rcon);
aes_addRoundKey(buf, &ctx->key[16]);
}
else aes_addRoundKey(buf, ctx->key);
aes_mixColumns_inv(buf);
aes_shiftRows_inv(buf);
aes_subBytes_inv(buf);
}
aes_addRoundKey(buf, ctx->key);
aes_cbc(buf, iv);

memcpy(out + j * 16, buf, 16);
memcpy(iv_change_2, iv_change_1, 16);
}
else
{
memcpy(iv_change_1, buf, 16);
aes_addRoundKey_cpy(buf, ctx->deckey, ctx->key);
aes_shiftRows_inv(buf);
aes_subBytes_inv(buf);

for (i = 14, rcon = 0x80; --i;)
{
if ((i & 1))
{
aes_expandDecKey(ctx->key, &rcon);
aes_addRoundKey(buf, &ctx->key[16]);
}
else aes_addRoundKey(buf, ctx->key);
aes_mixColumns_inv(buf);
aes_shiftRows_inv(buf);
aes_subBytes_inv(buf);
}
aes_addRoundKey(buf, ctx->key);
aes_cbc(buf, iv_change_2);

memcpy(out + j * 16, buf, 16);
memcpy(iv_change_2, iv_change_1, 16);
}
}

}

unsigned char * AES_CBC_PKCS5_Encrypt(unsigned char *src, int srcLen, unsigned char *key, int* dstLen)
{
//PKCS5 PADDING
int quotient = srcLen / AES_BLOCK_SIZE;
int mod = srcLen % AES_BLOCK_SIZE;
int blockCount = quotient + 1;

int padding = AES_BLOCK_SIZE - mod;
unsigned char *in = (char *)malloc(AES_BLOCK_SIZE*blockCount);
memset(in, padding, AES_BLOCK_SIZE*blockCount);
memcpy(in, src, srcLen);

//out
unsigned char *out = (unsigned char *)malloc(AES_BLOCK_SIZE*blockCount);
memset(out, 0x00, AES_BLOCK_SIZE*blockCount);

//iv
unsigned char iv[AES_BLOCK_SIZE];
memset(iv, 0x00, AES_BLOCK_SIZE);

//ase256
aes256_context ctx;
aes256_init(&ctx, key);
aes256_encrypt_cbc(&ctx, in, AES_BLOCK_SIZE*blockCount, iv, out);

//to hex
/*
*dstLen = AES_BLOCK_SIZE*blockCount * 2;
unsigned char *dst = (unsigned char *)malloc(AES_BLOCK_SIZE*blockCount * 2 + 1);
memset(dst, 0x00, AES_BLOCK_SIZE*blockCount * 2 + 1);
for (int i = 0; i < AES_BLOCK_SIZE*blockCount; i++)
{
sprintf(dst + strlen(dst), "%02x", out[i]);
}
free(out);
*/
*dstLen = AES_BLOCK_SIZE*blockCount;
return out;
}

unsigned char * AES_CBC_PKCS5_Decrypt(unsigned char *src, int srcLen, unsigned char *key, int* dstLen)
{
//iv
unsigned char iv[AES_BLOCK_SIZE];
memset(iv, 0x00, AES_BLOCK_SIZE);

unsigned char *out = (unsigned char *)malloc(srcLen);
memset(out, 0x00, srcLen);

//ase
aes256_context ctx;
aes256_init(&ctx, key);
aes256_decrypt_cbc(&ctx, src, srcLen, iv, out);

//unpadding
int padding = out[srcLen - 1];
int dlen = srcLen - padding;

//dst
if (dlen <= 0){
free(out);
return NULL;
}
unsigned char *dst = (unsigned char *)malloc(dlen);
memset(dst, 0x00, dlen);
memcpy(dst, out, dlen);
free(out);
*dstLen = dlen;
return dst;
}

/*aes256_decrypt_cbc*/