1 files changed, 1429 insertions, 0 deletions

diff --git a/openaes/src/oaes_lib.c b/openaes/src/oaes_lib.c
new file mode 100644
index 000000000..7cfdc1c06
--- /dev/null
+++ b/openaes/src/oaes_lib.c
@@ -0,0 +1,1429 @@
+/* 
+ * ---------------------------------------------------------------------------
+ * OpenAES License
+ * ---------------------------------------------------------------------------
+ * Copyright (c) 2012, Nabil S. Al Ramli, www.nalramli.com
+ * All rights reserved.
+ * 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ * 
+ *   - Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *   - Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ * ---------------------------------------------------------------------------
+ */
+static const char _NR[] = {
+	0x4e,0x61,0x62,0x69,0x6c,0x20,0x53,0x2e,0x20,
+	0x41,0x6c,0x20,0x52,0x61,0x6d,0x6c,0x69,0x00 };
+
+#include <stddef.h>
+#include <time.h> 
+#include <sys/timeb.h>
+#include <malloc.h>
+#include <string.h>
+
+#ifdef WIN32
+#include <process.h>
+#endif
+
+#include "oaes_config.h"
+#include "oaes_lib.h"
+
+#ifdef OAES_HAVE_ISAAC
+#include "rand.h"
+#endif // OAES_HAVE_ISAAC
+
+#define OAES_RKEY_LEN 4
+#define OAES_COL_LEN 4
+#define OAES_ROUND_BASE 7
+
+// the block is padded
+#define OAES_FLAG_PAD 0x01
+
+#ifndef min
+# define min(a,b) (((a)<(b)) ? (a) : (b))
+#endif /* min */
+
+typedef struct _oaes_key
+{
+	size_t data_len;
+	uint8_t *data;
+	size_t exp_data_len;
+	uint8_t *exp_data;
+	size_t num_keys;
+	size_t key_base;
+} oaes_key;
+
+typedef struct _oaes_ctx
+{
+#ifdef OAES_HAVE_ISAAC
+  randctx * rctx;
+#endif // OAES_HAVE_ISAAC
+
+#ifdef OAES_DEBUG
+	oaes_step_cb step_cb;
+#endif // OAES_DEBUG
+
+	oaes_key * key;
+	OAES_OPTION options;
+	uint8_t iv[OAES_BLOCK_SIZE];
+} oaes_ctx;
+
+// "OAES<8-bit header version><8-bit type><16-bit options><8-bit flags><56-bit reserved>"
+static uint8_t oaes_header[OAES_BLOCK_SIZE] = {
+	// 		0,    1,    2,    3,    4,    5,    6,    7,    8,    9,    a,    b,    c,    d,    e,    f,
+	/*0*/	0x4f, 0x41, 0x45, 0x53, 0x01, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+};
+static uint8_t oaes_gf_8[] = {
+	0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36 };
+
+static uint8_t oaes_sub_byte_value[16][16] = {
+	// 		0,    1,    2,    3,    4,    5,    6,    7,    8,    9,    a,    b,    c,    d,    e,    f,
+	/*0*/	0x63, 0x7c, 0x77, 0x7b, 0xf2, 0x6b, 0x6f, 0xc5, 0x30, 0x01, 0x67, 0x2b, 0xfe, 0xd7, 0xab, 0x76,
+	/*1*/	0xca, 0x82, 0xc9, 0x7d, 0xfa, 0x59, 0x47, 0xf0, 0xad, 0xd4, 0xa2, 0xaf, 0x9c, 0xa4, 0x72, 0xc0,
+	/*2*/	0xb7, 0xfd, 0x93, 0x26, 0x36, 0x3f, 0xf7, 0xcc, 0x34, 0xa5, 0xe5, 0xf1, 0x71, 0xd8, 0x31, 0x15,
+	/*3*/	0x04, 0xc7, 0x23, 0xc3, 0x18, 0x96, 0x05, 0x9a, 0x07, 0x12, 0x80, 0xe2, 0xeb, 0x27, 0xb2, 0x75,
+	/*4*/	0x09, 0x83, 0x2c, 0x1a, 0x1b, 0x6e, 0x5a, 0xa0, 0x52, 0x3b, 0xd6, 0xb3, 0x29, 0xe3, 0x2f, 0x84,
+	/*5*/	0x53, 0xd1, 0x00, 0xed, 0x20, 0xfc, 0xb1, 0x5b, 0x6a, 0xcb, 0xbe, 0x39, 0x4a, 0x4c, 0x58, 0xcf,
+	/*6*/	0xd0, 0xef, 0xaa, 0xfb, 0x43, 0x4d, 0x33, 0x85, 0x45, 0xf9, 0x02, 0x7f, 0x50, 0x3c, 0x9f, 0xa8,
+	/*7*/	0x51, 0xa3, 0x40, 0x8f, 0x92, 0x9d, 0x38, 0xf5, 0xbc, 0xb6, 0xda, 0x21, 0x10, 0xff, 0xf3, 0xd2,
+	/*8*/	0xcd, 0x0c, 0x13, 0xec, 0x5f, 0x97, 0x44, 0x17, 0xc4, 0xa7, 0x7e, 0x3d, 0x64, 0x5d, 0x19, 0x73,
+	/*9*/	0x60, 0x81, 0x4f, 0xdc, 0x22, 0x2a, 0x90, 0x88, 0x46, 0xee, 0xb8, 0x14, 0xde, 0x5e, 0x0b, 0xdb,
+	/*a*/	0xe0, 0x32, 0x3a, 0x0a, 0x49, 0x06, 0x24, 0x5c, 0xc2, 0xd3, 0xac, 0x62, 0x91, 0x95, 0xe4, 0x79,
+	/*b*/	0xe7, 0xc8, 0x37, 0x6d, 0x8d, 0xd5, 0x4e, 0xa9, 0x6c, 0x56, 0xf4, 0xea, 0x65, 0x7a, 0xae, 0x08,
+	/*c*/	0xba, 0x78, 0x25, 0x2e, 0x1c, 0xa6, 0xb4, 0xc6, 0xe8, 0xdd, 0x74, 0x1f, 0x4b, 0xbd, 0x8b, 0x8a,
+	/*d*/	0x70, 0x3e, 0xb5, 0x66, 0x48, 0x03, 0xf6, 0x0e, 0x61, 0x35, 0x57, 0xb9, 0x86, 0xc1, 0x1d, 0x9e,
+	/*e*/	0xe1, 0xf8, 0x98, 0x11, 0x69, 0xd9, 0x8e, 0x94, 0x9b, 0x1e, 0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf,
+	/*f*/	0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68, 0x41, 0x99, 0x2d, 0x0f, 0xb0, 0x54, 0xbb, 0x16,
+};
+
+static uint8_t oaes_inv_sub_byte_value[16][16] = {
+	// 		0,    1,    2,    3,    4,    5,    6,    7,    8,    9,    a,    b,    c,    d,    e,    f,
+	/*0*/	0x52, 0x09, 0x6a, 0xd5, 0x30, 0x36, 0xa5, 0x38, 0xbf, 0x40, 0xa3, 0x9e, 0x81, 0xf3, 0xd7, 0xfb,
+	/*1*/	0x7c, 0xe3, 0x39, 0x82, 0x9b, 0x2f, 0xff, 0x87, 0x34, 0x8e, 0x43, 0x44, 0xc4, 0xde, 0xe9, 0xcb,
+	/*2*/	0x54, 0x7b, 0x94, 0x32, 0xa6, 0xc2, 0x23, 0x3d, 0xee, 0x4c, 0x95, 0x0b, 0x42, 0xfa, 0xc3, 0x4e,
+	/*3*/	0x08, 0x2e, 0xa1, 0x66, 0x28, 0xd9, 0x24, 0xb2, 0x76, 0x5b, 0xa2, 0x49, 0x6d, 0x8b, 0xd1, 0x25,
+	/*4*/	0x72, 0xf8, 0xf6, 0x64, 0x86, 0x68, 0x98, 0x16, 0xd4, 0xa4, 0x5c, 0xcc, 0x5d, 0x65, 0xb6, 0x92,
+	/*5*/	0x6c, 0x70, 0x48, 0x50, 0xfd, 0xed, 0xb9, 0xda, 0x5e, 0x15, 0x46, 0x57, 0xa7, 0x8d, 0x9d, 0x84,
+	/*6*/	0x90, 0xd8, 0xab, 0x00, 0x8c, 0xbc, 0xd3, 0x0a, 0xf7, 0xe4, 0x58, 0x05, 0xb8, 0xb3, 0x45, 0x06,
+	/*7*/	0xd0, 0x2c, 0x1e, 0x8f, 0xca, 0x3f, 0x0f, 0x02, 0xc1, 0xaf, 0xbd, 0x03, 0x01, 0x13, 0x8a, 0x6b,
+	/*8*/	0x3a, 0x91, 0x11, 0x41, 0x4f, 0x67, 0xdc, 0xea, 0x97, 0xf2, 0xcf, 0xce, 0xf0, 0xb4, 0xe6, 0x73,
+	/*9*/	0x96, 0xac, 0x74, 0x22, 0xe7, 0xad, 0x35, 0x85, 0xe2, 0xf9, 0x37, 0xe8, 0x1c, 0x75, 0xdf, 0x6e,
+	/*a*/	0x47, 0xf1, 0x1a, 0x71, 0x1d, 0x29, 0xc5, 0x89, 0x6f, 0xb7, 0x62, 0x0e, 0xaa, 0x18, 0xbe, 0x1b,
+	/*b*/	0xfc, 0x56, 0x3e, 0x4b, 0xc6, 0xd2, 0x79, 0x20, 0x9a, 0xdb, 0xc0, 0xfe, 0x78, 0xcd, 0x5a, 0xf4,
+	/*c*/	0x1f, 0xdd, 0xa8, 0x33, 0x88, 0x07, 0xc7, 0x31, 0xb1, 0x12, 0x10, 0x59, 0x27, 0x80, 0xec, 0x5f,
+	/*d*/	0x60, 0x51, 0x7f, 0xa9, 0x19, 0xb5, 0x4a, 0x0d, 0x2d, 0xe5, 0x7a, 0x9f, 0x93, 0xc9, 0x9c, 0xef,
+	/*e*/	0xa0, 0xe0, 0x3b, 0x4d, 0xae, 0x2a, 0xf5, 0xb0, 0xc8, 0xeb, 0xbb, 0x3c, 0x83, 0x53, 0x99, 0x61,
+	/*f*/	0x17, 0x2b, 0x04, 0x7e, 0xba, 0x77, 0xd6, 0x26, 0xe1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0c, 0x7d,
+};
+
+static uint8_t oaes_gf_mul_2[16][16] = {
+	// 		0,    1,    2,    3,    4,    5,    6,    7,    8,    9,    a,    b,    c,    d,    e,    f,
+	/*0*/	0x00, 0x02, 0x04, 0x06, 0x08, 0x0a, 0x0c, 0x0e, 0x10, 0x12, 0x14, 0x16, 0x18, 0x1a, 0x1c, 0x1e,
+	/*1*/	0x20, 0x22, 0x24, 0x26, 0x28, 0x2a, 0x2c, 0x2e, 0x30, 0x32, 0x34, 0x36, 0x38, 0x3a, 0x3c, 0x3e,
+	/*2*/	0x40, 0x42, 0x44, 0x46, 0x48, 0x4a, 0x4c, 0x4e, 0x50, 0x52, 0x54, 0x56, 0x58, 0x5a, 0x5c, 0x5e,
+	/*3*/	0x60, 0x62, 0x64, 0x66, 0x68, 0x6a, 0x6c, 0x6e, 0x70, 0x72, 0x74, 0x76, 0x78, 0x7a, 0x7c, 0x7e,
+	/*4*/	0x80, 0x82, 0x84, 0x86, 0x88, 0x8a, 0x8c, 0x8e, 0x90, 0x92, 0x94, 0x96, 0x98, 0x9a, 0x9c, 0x9e,
+	/*5*/	0xa0, 0xa2, 0xa4, 0xa6, 0xa8, 0xaa, 0xac, 0xae, 0xb0, 0xb2, 0xb4, 0xb6, 0xb8, 0xba, 0xbc, 0xbe,
+	/*6*/	0xc0, 0xc2, 0xc4, 0xc6, 0xc8, 0xca, 0xcc, 0xce, 0xd0, 0xd2, 0xd4, 0xd6, 0xd8, 0xda, 0xdc, 0xde,
+	/*7*/	0xe0, 0xe2, 0xe4, 0xe6, 0xe8, 0xea, 0xec, 0xee, 0xf0, 0xf2, 0xf4, 0xf6, 0xf8, 0xfa, 0xfc, 0xfe,
+	/*8*/	0x1b, 0x19, 0x1f, 0x1d, 0x13, 0x11, 0x17, 0x15, 0x0b, 0x09, 0x0f, 0x0d, 0x03, 0x01, 0x07, 0x05,
+	/*9*/	0x3b, 0x39, 0x3f, 0x3d, 0x33, 0x31, 0x37, 0x35, 0x2b, 0x29, 0x2f, 0x2d, 0x23, 0x21, 0x27, 0x25,
+	/*a*/	0x5b, 0x59, 0x5f, 0x5d, 0x53, 0x51, 0x57, 0x55, 0x4b, 0x49, 0x4f, 0x4d, 0x43, 0x41, 0x47, 0x45,
+	/*b*/	0x7b, 0x79, 0x7f, 0x7d, 0x73, 0x71, 0x77, 0x75, 0x6b, 0x69, 0x6f, 0x6d, 0x63, 0x61, 0x67, 0x65,
+	/*c*/	0x9b, 0x99, 0x9f, 0x9d, 0x93, 0x91, 0x97, 0x95, 0x8b, 0x89, 0x8f, 0x8d, 0x83, 0x81, 0x87, 0x85,
+	/*d*/	0xbb, 0xb9, 0xbf, 0xbd, 0xb3, 0xb1, 0xb7, 0xb5, 0xab, 0xa9, 0xaf, 0xad, 0xa3, 0xa1, 0xa7, 0xa5,
+	/*e*/	0xdb, 0xd9, 0xdf, 0xdd, 0xd3, 0xd1, 0xd7, 0xd5, 0xcb, 0xc9, 0xcf, 0xcd, 0xc3, 0xc1, 0xc7, 0xc5,
+	/*f*/	0xfb, 0xf9, 0xff, 0xfd, 0xf3, 0xf1, 0xf7, 0xf5, 0xeb, 0xe9, 0xef, 0xed, 0xe3, 0xe1, 0xe7, 0xe5,
+};
+
+static uint8_t oaes_gf_mul_3[16][16] = {
+	// 		0,    1,    2,    3,    4,    5,    6,    7,    8,    9,    a,    b,    c,    d,    e,    f,
+	/*0*/	0x00, 0x03, 0x06, 0x05, 0x0c, 0x0f, 0x0a, 0x09, 0x18, 0x1b, 0x1e, 0x1d, 0x14, 0x17, 0x12, 0x11,
+	/*1*/	0x30, 0x33, 0x36, 0x35, 0x3c, 0x3f, 0x3a, 0x39, 0x28, 0x2b, 0x2e, 0x2d, 0x24, 0x27, 0x22, 0x21,
+	/*2*/	0x60, 0x63, 0x66, 0x65, 0x6c, 0x6f, 0x6a, 0x69, 0x78, 0x7b, 0x7e, 0x7d, 0x74, 0x77, 0x72, 0x71,
+	/*3*/	0x50, 0x53, 0x56, 0x55, 0x5c, 0x5f, 0x5a, 0x59, 0x48, 0x4b, 0x4e, 0x4d, 0x44, 0x47, 0x42, 0x41,
+	/*4*/	0xc0, 0xc3, 0xc6, 0xc5, 0xcc, 0xcf, 0xca, 0xc9, 0xd8, 0xdb, 0xde, 0xdd, 0xd4, 0xd7, 0xd2, 0xd1,
+	/*5*/	0xf0, 0xf3, 0xf6, 0xf5, 0xfc, 0xff, 0xfa, 0xf9, 0xe8, 0xeb, 0xee, 0xed, 0xe4, 0xe7, 0xe2, 0xe1,
+	/*6*/	0xa0, 0xa3, 0xa6, 0xa5, 0xac, 0xaf, 0xaa, 0xa9, 0xb8, 0xbb, 0xbe, 0xbd, 0xb4, 0xb7, 0xb2, 0xb1,
+	/*7*/	0x90, 0x93, 0x96, 0x95, 0x9c, 0x9f, 0x9a, 0x99, 0x88, 0x8b, 0x8e, 0x8d, 0x84, 0x87, 0x82, 0x81,
+	/*8*/	0x9b, 0x98, 0x9d, 0x9e, 0x97, 0x94, 0x91, 0x92, 0x83, 0x80, 0x85, 0x86, 0x8f, 0x8c, 0x89, 0x8a,
+	/*9*/	0xab, 0xa8, 0xad, 0xae, 0xa7, 0xa4, 0xa1, 0xa2, 0xb3, 0xb0, 0xb5, 0xb6, 0xbf, 0xbc, 0xb9, 0xba,
+	/*a*/	0xfb, 0xf8, 0xfd, 0xfe, 0xf7, 0xf4, 0xf1, 0xf2, 0xe3, 0xe0, 0xe5, 0xe6, 0xef, 0xec, 0xe9, 0xea,
+	/*b*/	0xcb, 0xc8, 0xcd, 0xce, 0xc7, 0xc4, 0xc1, 0xc2, 0xd3, 0xd0, 0xd5, 0xd6, 0xdf, 0xdc, 0xd9, 0xda,
+	/*c*/	0x5b, 0x58, 0x5d, 0x5e, 0x57, 0x54, 0x51, 0x52, 0x43, 0x40, 0x45, 0x46, 0x4f, 0x4c, 0x49, 0x4a,
+	/*d*/	0x6b, 0x68, 0x6d, 0x6e, 0x67, 0x64, 0x61, 0x62, 0x73, 0x70, 0x75, 0x76, 0x7f, 0x7c, 0x79, 0x7a,
+	/*e*/	0x3b, 0x38, 0x3d, 0x3e, 0x37, 0x34, 0x31, 0x32, 0x23, 0x20, 0x25, 0x26, 0x2f, 0x2c, 0x29, 0x2a,
+	/*f*/	0x0b, 0x08, 0x0d, 0x0e, 0x07, 0x04, 0x01, 0x02, 0x13, 0x10, 0x15, 0x16, 0x1f, 0x1c, 0x19, 0x1a,
+};
+
+static uint8_t oaes_gf_mul_9[16][16] = {
+	// 		0,    1,    2,    3,    4,    5,    6,    7,    8,    9,    a,    b,    c,    d,    e,    f,
+	/*0*/	0x00, 0x09, 0x12, 0x1b, 0x24, 0x2d, 0x36, 0x3f, 0x48, 0x41, 0x5a, 0x53, 0x6c, 0x65, 0x7e, 0x77,
+	/*1*/	0x90, 0x99, 0x82, 0x8b, 0xb4, 0xbd, 0xa6, 0xaf, 0xd8, 0xd1, 0xca, 0xc3, 0xfc, 0xf5, 0xee, 0xe7,
+	/*2*/	0x3b, 0x32, 0x29, 0x20, 0x1f, 0x16, 0x0d, 0x04, 0x73, 0x7a, 0x61, 0x68, 0x57, 0x5e, 0x45, 0x4c,
+	/*3*/	0xab, 0xa2, 0xb9, 0xb0, 0x8f, 0x86, 0x9d, 0x94, 0xe3, 0xea, 0xf1, 0xf8, 0xc7, 0xce, 0xd5, 0xdc,
+	/*4*/	0x76, 0x7f, 0x64, 0x6d, 0x52, 0x5b, 0x40, 0x49, 0x3e, 0x37, 0x2c, 0x25, 0x1a, 0x13, 0x08, 0x01,
+	/*5*/	0xe6, 0xef, 0xf4, 0xfd, 0xc2, 0xcb, 0xd0, 0xd9, 0xae, 0xa7, 0xbc, 0xb5, 0x8a, 0x83, 0x98, 0x91,
+	/*6*/	0x4d, 0x44, 0x5f, 0x56, 0x69, 0x60, 0x7b, 0x72, 0x05, 0x0c, 0x17, 0x1e, 0x21, 0x28, 0x33, 0x3a,
+	/*7*/	0xdd, 0xd4, 0xcf, 0xc6, 0xf9, 0xf0, 0xeb, 0xe2, 0x95, 0x9c, 0x87, 0x8e, 0xb1, 0xb8, 0xa3, 0xaa,
+	/*8*/	0xec, 0xe5, 0xfe, 0xf7, 0xc8, 0xc1, 0xda, 0xd3, 0xa4, 0xad, 0xb6, 0xbf, 0x80, 0x89, 0x92, 0x9b,
+	/*9*/	0x7c, 0x75, 0x6e, 0x67, 0x58, 0x51, 0x4a, 0x43, 0x34, 0x3d, 0x26, 0x2f, 0x10, 0x19, 0x02, 0x0b,
+	/*a*/	0xd7, 0xde, 0xc5, 0xcc, 0xf3, 0xfa, 0xe1, 0xe8, 0x9f, 0x96, 0x8d, 0x84, 0xbb, 0xb2, 0xa9, 0xa0,
+	/*b*/	0x47, 0x4e, 0x55, 0x5c, 0x63, 0x6a, 0x71, 0x78, 0x0f, 0x06, 0x1d, 0x14, 0x2b, 0x22, 0x39, 0x30,
+	/*c*/	0x9a, 0x93, 0x88, 0x81, 0xbe, 0xb7, 0xac, 0xa5, 0xd2, 0xdb, 0xc0, 0xc9, 0xf6, 0xff, 0xe4, 0xed,
+	/*d*/	0x0a, 0x03, 0x18, 0x11, 0x2e, 0x27, 0x3c, 0x35, 0x42, 0x4b, 0x50, 0x59, 0x66, 0x6f, 0x74, 0x7d,
+	/*e*/	0xa1, 0xa8, 0xb3, 0xba, 0x85, 0x8c, 0x97, 0x9e, 0xe9, 0xe0, 0xfb, 0xf2, 0xcd, 0xc4, 0xdf, 0xd6,
+	/*f*/	0x31, 0x38, 0x23, 0x2a, 0x15, 0x1c, 0x07, 0x0e, 0x79, 0x70, 0x6b, 0x62, 0x5d, 0x54, 0x4f, 0x46,
+};
+
+static uint8_t oaes_gf_mul_b[16][16] = {
+	// 		0,    1,    2,    3,    4,    5,    6,    7,    8,    9,    a,    b,    c,    d,    e,    f,
+	/*0*/	0x00, 0x0b, 0x16, 0x1d, 0x2c, 0x27, 0x3a, 0x31, 0x58, 0x53, 0x4e, 0x45, 0x74, 0x7f, 0x62, 0x69,
+	/*1*/	0xb0, 0xbb, 0xa6, 0xad, 0x9c, 0x97, 0x8a, 0x81, 0xe8, 0xe3, 0xfe, 0xf5, 0xc4, 0xcf, 0xd2, 0xd9,
+	/*2*/	0x7b, 0x70, 0x6d, 0x66, 0x57, 0x5c, 0x41, 0x4a, 0x23, 0x28, 0x35, 0x3e, 0x0f, 0x04, 0x19, 0x12,
+	/*3*/	0xcb, 0xc0, 0xdd, 0xd6, 0xe7, 0xec, 0xf1, 0xfa, 0x93, 0x98, 0x85, 0x8e, 0xbf, 0xb4, 0xa9, 0xa2,
+	/*4*/	0xf6, 0xfd, 0xe0, 0xeb, 0xda, 0xd1, 0xcc, 0xc7, 0xae, 0xa5, 0xb8, 0xb3, 0x82, 0x89, 0x94, 0x9f,
+	/*5*/	0x46, 0x4d, 0x50, 0x5b, 0x6a, 0x61, 0x7c, 0x77, 0x1e, 0x15, 0x08, 0x03, 0x32, 0x39, 0x24, 0x2f,
+	/*6*/	0x8d, 0x86, 0x9b, 0x90, 0xa1, 0xaa, 0xb7, 0xbc, 0xd5, 0xde, 0xc3, 0xc8, 0xf9, 0xf2, 0xef, 0xe4,
+	/*7*/	0x3d, 0x36, 0x2b, 0x20, 0x11, 0x1a, 0x07, 0x0c, 0x65, 0x6e, 0x73, 0x78, 0x49, 0x42, 0x5f, 0x54,
+	/*8*/	0xf7, 0xfc, 0xe1, 0xea, 0xdb, 0xd0, 0xcd, 0xc6, 0xaf, 0xa4, 0xb9, 0xb2, 0x83, 0x88, 0x95, 0x9e,
+	/*9*/	0x47, 0x4c, 0x51, 0x5a, 0x6b, 0x60, 0x7d, 0x76, 0x1f, 0x14, 0x09, 0x02, 0x33, 0x38, 0x25, 0x2e,
+	/*a*/	0x8c, 0x87, 0x9a, 0x91, 0xa0, 0xab, 0xb6, 0xbd, 0xd4, 0xdf, 0xc2, 0xc9, 0xf8, 0xf3, 0xee, 0xe5,
+	/*b*/	0x3c, 0x37, 0x2a, 0x21, 0x10, 0x1b, 0x06, 0x0d, 0x64, 0x6f, 0x72, 0x79, 0x48, 0x43, 0x5e, 0x55,
+	/*c*/	0x01, 0x0a, 0x17, 0x1c, 0x2d, 0x26, 0x3b, 0x30, 0x59, 0x52, 0x4f, 0x44, 0x75, 0x7e, 0x63, 0x68,
+	/*d*/	0xb1, 0xba, 0xa7, 0xac, 0x9d, 0x96, 0x8b, 0x80, 0xe9, 0xe2, 0xff, 0xf4, 0xc5, 0xce, 0xd3, 0xd8,
+	/*e*/	0x7a, 0x71, 0x6c, 0x67, 0x56, 0x5d, 0x40, 0x4b, 0x22, 0x29, 0x34, 0x3f, 0x0e, 0x05, 0x18, 0x13,
+	/*f*/	0xca, 0xc1, 0xdc, 0xd7, 0xe6, 0xed, 0xf0, 0xfb, 0x92, 0x99, 0x84, 0x8f, 0xbe, 0xb5, 0xa8, 0xa3,
+};
+
+static uint8_t oaes_gf_mul_d[16][16] = {
+	// 		0,    1,    2,    3,    4,    5,    6,    7,    8,    9,    a,    b,    c,    d,    e,    f,
+	/*0*/	0x00, 0x0d, 0x1a, 0x17, 0x34, 0x39, 0x2e, 0x23, 0x68, 0x65, 0x72, 0x7f, 0x5c, 0x51, 0x46, 0x4b,
+	/*1*/	0xd0, 0xdd, 0xca, 0xc7, 0xe4, 0xe9, 0xfe, 0xf3, 0xb8, 0xb5, 0xa2, 0xaf, 0x8c, 0x81, 0x96, 0x9b,
+	/*2*/	0xbb, 0xb6, 0xa1, 0xac, 0x8f, 0x82, 0x95, 0x98, 0xd3, 0xde, 0xc9, 0xc4, 0xe7, 0xea, 0xfd, 0xf0,
+	/*3*/	0x6b, 0x66, 0x71, 0x7c, 0x5f, 0x52, 0x45, 0x48, 0x03, 0x0e, 0x19, 0x14, 0x37, 0x3a, 0x2d, 0x20,
+	/*4*/	0x6d, 0x60, 0x77, 0x7a, 0x59, 0x54, 0x43, 0x4e, 0x05, 0x08, 0x1f, 0x12, 0x31, 0x3c, 0x2b, 0x26,
+	/*5*/	0xbd, 0xb0, 0xa7, 0xaa, 0x89, 0x84, 0x93, 0x9e, 0xd5, 0xd8, 0xcf, 0xc2, 0xe1, 0xec, 0xfb, 0xf6,
+	/*6*/	0xd6, 0xdb, 0xcc, 0xc1, 0xe2, 0xef, 0xf8, 0xf5, 0xbe, 0xb3, 0xa4, 0xa9, 0x8a, 0x87, 0x90, 0x9d,
+	/*7*/	0x06, 0x0b, 0x1c, 0x11, 0x32, 0x3f, 0x28, 0x25, 0x6e, 0x63, 0x74, 0x79, 0x5a, 0x57, 0x40, 0x4d,
+	/*8*/	0xda, 0xd7, 0xc0, 0xcd, 0xee, 0xe3, 0xf4, 0xf9, 0xb2, 0xbf, 0xa8, 0xa5, 0x86, 0x8b, 0x9c, 0x91,
+	/*9*/	0x0a, 0x07, 0x10, 0x1d, 0x3e, 0x33, 0x24, 0x29, 0x62, 0x6f, 0x78, 0x75, 0x56, 0x5b, 0x4c, 0x41,
+	/*a*/	0x61, 0x6c, 0x7b, 0x76, 0x55, 0x58, 0x4f, 0x42, 0x09, 0x04, 0x13, 0x1e, 0x3d, 0x30, 0x27, 0x2a,
+	/*b*/	0xb1, 0xbc, 0xab, 0xa6, 0x85, 0x88, 0x9f, 0x92, 0xd9, 0xd4, 0xc3, 0xce, 0xed, 0xe0, 0xf7, 0xfa,
+	/*c*/	0xb7, 0xba, 0xad, 0xa0, 0x83, 0x8e, 0x99, 0x94, 0xdf, 0xd2, 0xc5, 0xc8, 0xeb, 0xe6, 0xf1, 0xfc,
+	/*d*/	0x67, 0x6a, 0x7d, 0x70, 0x53, 0x5e, 0x49, 0x44, 0x0f, 0x02, 0x15, 0x18, 0x3b, 0x36, 0x21, 0x2c,
+	/*e*/	0x0c, 0x01, 0x16, 0x1b, 0x38, 0x35, 0x22, 0x2f, 0x64, 0x69, 0x7e, 0x73, 0x50, 0x5d, 0x4a, 0x47,
+	/*f*/	0xdc, 0xd1, 0xc6, 0xcb, 0xe8, 0xe5, 0xf2, 0xff, 0xb4, 0xb9, 0xae, 0xa3, 0x80, 0x8d, 0x9a, 0x97,
+};
+
+static uint8_t oaes_gf_mul_e[16][16] = {
+	// 		0,    1,    2,    3,    4,    5,    6,    7,    8,    9,    a,    b,    c,    d,    e,    f,
+	/*0*/	0x00, 0x0e, 0x1c, 0x12, 0x38, 0x36, 0x24, 0x2a, 0x70, 0x7e, 0x6c, 0x62, 0x48, 0x46, 0x54, 0x5a,
+	/*1*/	0xe0, 0xee, 0xfc, 0xf2, 0xd8, 0xd6, 0xc4, 0xca, 0x90, 0x9e, 0x8c, 0x82, 0xa8, 0xa6, 0xb4, 0xba,
+	/*2*/	0xdb, 0xd5, 0xc7, 0xc9, 0xe3, 0xed, 0xff, 0xf1, 0xab, 0xa5, 0xb7, 0xb9, 0x93, 0x9d, 0x8f, 0x81,
+	/*3*/	0x3b, 0x35, 0x27, 0x29, 0x03, 0x0d, 0x1f, 0x11, 0x4b, 0x45, 0x57, 0x59, 0x73, 0x7d, 0x6f, 0x61,
+	/*4*/	0xad, 0xa3, 0xb1, 0xbf, 0x95, 0x9b, 0x89, 0x87, 0xdd, 0xd3, 0xc1, 0xcf, 0xe5, 0xeb, 0xf9, 0xf7,
+	/*5*/	0x4d, 0x43, 0x51, 0x5f, 0x75, 0x7b, 0x69, 0x67, 0x3d, 0x33, 0x21, 0x2f, 0x05, 0x0b, 0x19, 0x17,
+	/*6*/	0x76, 0x78, 0x6a, 0x64, 0x4e, 0x40, 0x52, 0x5c, 0x06, 0x08, 0x1a, 0x14, 0x3e, 0x30, 0x22, 0x2c,
+	/*7*/	0x96, 0x98, 0x8a, 0x84, 0xae, 0xa0, 0xb2, 0xbc, 0xe6, 0xe8, 0xfa, 0xf4, 0xde, 0xd0, 0xc2, 0xcc,
+	/*8*/	0x41, 0x4f, 0x5d, 0x53, 0x79, 0x77, 0x65, 0x6b, 0x31, 0x3f, 0x2d, 0x23, 0x09, 0x07, 0x15, 0x1b,
+	/*9*/	0xa1, 0xaf, 0xbd, 0xb3, 0x99, 0x97, 0x85, 0x8b, 0xd1, 0xdf, 0xcd, 0xc3, 0xe9, 0xe7, 0xf5, 0xfb,
+	/*a*/	0x9a, 0x94, 0x86, 0x88, 0xa2, 0xac, 0xbe, 0xb0, 0xea, 0xe4, 0xf6, 0xf8, 0xd2, 0xdc, 0xce, 0xc0,
+	/*b*/	0x7a, 0x74, 0x66, 0x68, 0x42, 0x4c, 0x5e, 0x50, 0x0a, 0x04, 0x16, 0x18, 0x32, 0x3c, 0x2e, 0x20,
+	/*c*/	0xec, 0xe2, 0xf0, 0xfe, 0xd4, 0xda, 0xc8, 0xc6, 0x9c, 0x92, 0x80, 0x8e, 0xa4, 0xaa, 0xb8, 0xb6,
+	/*d*/	0x0c, 0x02, 0x10, 0x1e, 0x34, 0x3a, 0x28, 0x26, 0x7c, 0x72, 0x60, 0x6e, 0x44, 0x4a, 0x58, 0x56,
+	/*e*/	0x37, 0x39, 0x2b, 0x25, 0x0f, 0x01, 0x13, 0x1d, 0x47, 0x49, 0x5b, 0x55, 0x7f, 0x71, 0x63, 0x6d,
+	/*f*/	0xd7, 0xd9, 0xcb, 0xc5, 0xef, 0xe1, 0xf3, 0xfd, 0xa7, 0xa9, 0xbb, 0xb5, 0x9f, 0x91, 0x83, 0x8d,
+};
+
+static OAES_RET oaes_sub_byte( uint8_t * byte )
+{
+	size_t _x, _y;
+	
+	if( NULL == byte )
+		return OAES_RET_ARG1;
+
+	_x = _y = *byte;
+	_x &= 0x0f;
+	_y &= 0xf0;
+	_y >>= 4;
+	*byte = oaes_sub_byte_value[_y][_x];
+	
+	return OAES_RET_SUCCESS;
+}
+
+static OAES_RET oaes_inv_sub_byte( uint8_t * byte )
+{
+	size_t _x, _y;
+	
+	if( NULL == byte )
+		return OAES_RET_ARG1;
+
+	_x = _y = *byte;
+	_x &= 0x0f;
+	_y &= 0xf0;
+	_y >>= 4;
+	*byte = oaes_inv_sub_byte_value[_y][_x];
+	
+	return OAES_RET_SUCCESS;
+}
+
+static OAES_RET oaes_word_rot_right( uint8_t word[OAES_COL_LEN] )
+{
+	uint8_t _temp[OAES_COL_LEN];
+	
+	if( NULL == word )
+		return OAES_RET_ARG1;
+
+	memcpy( _temp + 1, word, OAES_COL_LEN - 1 );
+	_temp[0] = word[OAES_COL_LEN - 1];
+	memcpy( word, _temp, OAES_COL_LEN );
+	
+	return OAES_RET_SUCCESS;
+}
+
+static OAES_RET oaes_word_rot_left( uint8_t word[OAES_COL_LEN] )
+{
+	uint8_t _temp[OAES_COL_LEN];
+	
+	if( NULL == word )
+		return OAES_RET_ARG1;
+
+	memcpy( _temp, word + 1, OAES_COL_LEN - 1 );
+	_temp[OAES_COL_LEN - 1] = word[0];
+	memcpy( word, _temp, OAES_COL_LEN );
+	
+	return OAES_RET_SUCCESS;
+}
+
+static OAES_RET oaes_shift_rows( uint8_t block[OAES_BLOCK_SIZE] )
+{
+	uint8_t _temp[OAES_BLOCK_SIZE];
+
+	if( NULL == block )
+		return OAES_RET_ARG1;
+
+	_temp[0x00] = block[0x00];
+	_temp[0x01] = block[0x05];
+	_temp[0x02] = block[0x0a];
+	_temp[0x03] = block[0x0f];
+	_temp[0x04] = block[0x04];
+	_temp[0x05] = block[0x09];
+	_temp[0x06] = block[0x0e];
+	_temp[0x07] = block[0x03];
+	_temp[0x08] = block[0x08];
+	_temp[0x09] = block[0x0d];
+	_temp[0x0a] = block[0x02];
+	_temp[0x0b] = block[0x07];
+	_temp[0x0c] = block[0x0c];
+	_temp[0x0d] = block[0x01];
+	_temp[0x0e] = block[0x06];
+	_temp[0x0f] = block[0x0b];
+	memcpy( block, _temp, OAES_BLOCK_SIZE );
+	
+	return OAES_RET_SUCCESS;
+}
+
+static OAES_RET oaes_inv_shift_rows( uint8_t block[OAES_BLOCK_SIZE] )
+{
+	uint8_t _temp[OAES_BLOCK_SIZE];
+
+	if( NULL == block )
+		return OAES_RET_ARG1;
+
+	_temp[0x00] = block[0x00];
+	_temp[0x01] = block[0x0d];
+	_temp[0x02] = block[0x0a];
+	_temp[0x03] = block[0x07];
+	_temp[0x04] = block[0x04];
+	_temp[0x05] = block[0x01];
+	_temp[0x06] = block[0x0e];
+	_temp[0x07] = block[0x0b];
+	_temp[0x08] = block[0x08];
+	_temp[0x09] = block[0x05];
+	_temp[0x0a] = block[0x02];
+	_temp[0x0b] = block[0x0f];
+	_temp[0x0c] = block[0x0c];
+	_temp[0x0d] = block[0x09];
+	_temp[0x0e] = block[0x06];
+	_temp[0x0f] = block[0x03];
+	memcpy( block, _temp, OAES_BLOCK_SIZE );
+	
+	return OAES_RET_SUCCESS;
+}
+
+static uint8_t oaes_gf_mul(uint8_t left, uint8_t right)
+{
+	size_t _x, _y;
+	
+	_x = _y = left;
+	_x &= 0x0f;
+	_y &= 0xf0;
+	_y >>= 4;
+	
+	switch( right )
+	{
+		case 0x02:
+			return oaes_gf_mul_2[_y][_x];
+			break;
+		case 0x03:
+			return oaes_gf_mul_3[_y][_x];
+			break;
+		case 0x09:
+			return oaes_gf_mul_9[_y][_x];
+			break;
+		case 0x0b:
+			return oaes_gf_mul_b[_y][_x];
+			break;
+		case 0x0d:
+			return oaes_gf_mul_d[_y][_x];
+			break;
+		case 0x0e:
+			return oaes_gf_mul_e[_y][_x];
+			break;
+		default:
+			return left;
+			break;
+	}
+}
+
+static OAES_RET oaes_mix_cols( uint8_t word[OAES_COL_LEN] )
+{
+	uint8_t _temp[OAES_COL_LEN];
+
+	if( NULL == word )
+		return OAES_RET_ARG1;
+	
+	_temp[0] = oaes_gf_mul(word[0], 0x02) ^ oaes_gf_mul( word[1], 0x03 ) ^
+			word[2] ^ word[3];
+	_temp[1] = word[0] ^ oaes_gf_mul( word[1], 0x02 ) ^
+			oaes_gf_mul( word[2], 0x03 ) ^ word[3];
+	_temp[2] = word[0] ^ word[1] ^
+			oaes_gf_mul( word[2], 0x02 ) ^ oaes_gf_mul( word[3], 0x03 );
+	_temp[3] = oaes_gf_mul( word[0], 0x03 ) ^ word[1] ^
+			word[2] ^ oaes_gf_mul( word[3], 0x02 );
+	memcpy( word, _temp, OAES_COL_LEN );
+	
+	return OAES_RET_SUCCESS;
+}
+
+static OAES_RET oaes_inv_mix_cols( uint8_t word[OAES_COL_LEN] )
+{
+	uint8_t _temp[OAES_COL_LEN];
+
+	if( NULL == word )
+		return OAES_RET_ARG1;
+	
+	_temp[0] = oaes_gf_mul( word[0], 0x0e ) ^ oaes_gf_mul( word[1], 0x0b ) ^
+			oaes_gf_mul( word[2], 0x0d ) ^ oaes_gf_mul( word[3], 0x09 );
+	_temp[1] = oaes_gf_mul( word[0], 0x09 ) ^ oaes_gf_mul( word[1], 0x0e ) ^
+			oaes_gf_mul( word[2], 0x0b ) ^ oaes_gf_mul( word[3], 0x0d );
+	_temp[2] = oaes_gf_mul( word[0], 0x0d ) ^ oaes_gf_mul( word[1], 0x09 ) ^
+			oaes_gf_mul( word[2], 0x0e ) ^ oaes_gf_mul( word[3], 0x0b );
+	_temp[3] = oaes_gf_mul( word[0], 0x0b ) ^ oaes_gf_mul( word[1], 0x0d ) ^
+			oaes_gf_mul( word[2], 0x09 ) ^ oaes_gf_mul( word[3], 0x0e );
+	memcpy( word, _temp, OAES_COL_LEN );
+	
+	return OAES_RET_SUCCESS;
+}
+
+OAES_RET oaes_sprintf(
+		char * buf, size_t * buf_len, const uint8_t * data, size_t data_len )
+{
+	size_t _i, _buf_len_in;
+	char _temp[4];
+	
+	if( NULL == buf_len )
+		return OAES_RET_ARG2;
+
+	_buf_len_in = *buf_len;
+	*buf_len = data_len * 3 + data_len / OAES_BLOCK_SIZE + 1;
+	
+	if( NULL == buf )
+		return OAES_RET_SUCCESS;
+
+	if( *buf_len > _buf_len_in )
+		return OAES_RET_BUF;
+
+	if( NULL == data )
+		return OAES_RET_ARG3;
+
+	strcpy( buf, "" );
+	
+	for( _i = 0; _i < data_len; _i++ )
+	{
+		sprintf( _temp, "%02x ", data[_i] );
+		strcat( buf, _temp );
+		if( _i && 0 == ( _i + 1 ) % OAES_BLOCK_SIZE )
+			strcat( buf, "\n" );
+	}
+	
+	return OAES_RET_SUCCESS;
+}
+
+#ifdef OAES_HAVE_ISAAC
+static void oaes_get_seed( char buf[RANDSIZ + 1] )
+{
+	struct timeb timer;
+	struct tm *gmTimer;
+	char * _test = NULL;
+	
+	ftime (&timer);
+	gmTimer = gmtime( &timer.time );
+	_test = (char *) calloc( sizeof( char ), timer.millitm );
+	sprintf( buf, "%04d%02d%02d%02d%02d%02d%03d%p%d",
+		gmTimer->tm_year + 1900, gmTimer->tm_mon + 1, gmTimer->tm_mday,
+		gmTimer->tm_hour, gmTimer->tm_min, gmTimer->tm_sec, timer.millitm,
+		_test + timer.millitm, getpid() );
+	
+	if( _test )
+		free( _test );
+}
+#else
+static uint32_t oaes_get_seed()
+{
+	struct timeb timer;
+	struct tm *gmTimer;
+	char * _test = NULL;
+	uint32_t _ret = 0;
+	
+	ftime (&timer);
+	gmTimer = gmtime( &timer.time );
+	_test = (char *) calloc( sizeof( char ), timer.millitm );
+	_ret = gmTimer->tm_year + 1900 + gmTimer->tm_mon + 1 + gmTimer->tm_mday +
+			gmTimer->tm_hour + gmTimer->tm_min + gmTimer->tm_sec + timer.millitm +
+			(uint32_t) ( _test + timer.millitm ) + getpid();
+
+	if( _test )
+		free( _test );
+	
+	return _ret;
+}
+#endif // OAES_HAVE_ISAAC
+
+static OAES_RET oaes_key_destroy( oaes_key ** key )
+{
+	if( NULL == *key )
+		return OAES_RET_SUCCESS;
+	
+	if( (*key)->data )
+	{
+		free( (*key)->data );
+		(*key)->data = NULL;
+	}
+	
+	if( (*key)->exp_data )
+	{
+		free( (*key)->exp_data );
+		(*key)->exp_data = NULL;
+	}
+	
+	(*key)->data_len = 0;
+	(*key)->exp_data_len = 0;
+	(*key)->num_keys = 0;
+	(*key)->key_base = 0;
+	free( *key );
+	*key = NULL;
+	
+	return OAES_RET_SUCCESS;
+}
+
+static OAES_RET oaes_key_expand( OAES_CTX * ctx )
+{
+	size_t _i, _j;
+	oaes_ctx * _ctx = (oaes_ctx *) ctx;
+	
+	if( NULL == _ctx )
+		return OAES_RET_ARG1;
+	
+	if( NULL == _ctx->key )
+		return OAES_RET_NOKEY;
+	
+	_ctx->key->key_base = _ctx->key->data_len / OAES_RKEY_LEN;
+	_ctx->key->num_keys =  _ctx->key->key_base + OAES_ROUND_BASE;
+					
+	_ctx->key->exp_data_len = _ctx->key->num_keys * OAES_RKEY_LEN * OAES_COL_LEN;
+	_ctx->key->exp_data = (uint8_t *)
+			calloc( _ctx->key->exp_data_len, sizeof( uint8_t ));
+	
+	if( NULL == _ctx->key->exp_data )
+		return OAES_RET_MEM;
+	
+	// the first _ctx->key->data_len are a direct copy
+	memcpy( _ctx->key->exp_data, _ctx->key->data, _ctx->key->data_len );
+
+	// apply ExpandKey algorithm for remainder
+	for( _i = _ctx->key->key_base; _i < _ctx->key->num_keys * OAES_RKEY_LEN; _i++ )
+	{
+		uint8_t _temp[OAES_COL_LEN];
+		
+		memcpy( _temp,
+				_ctx->key->exp_data + ( _i - 1 ) * OAES_RKEY_LEN, OAES_COL_LEN );
+		
+		// transform key column
+		if( 0 == _i % _ctx->key->key_base )
+		{
+			oaes_word_rot_left( _temp );
+
+			for( _j = 0; _j < OAES_COL_LEN; _j++ )
+				oaes_sub_byte( _temp + _j );
+
+			_temp[0] = _temp[0] ^ oaes_gf_8[ _i / _ctx->key->key_base - 1 ];
+		}
+		else if( _ctx->key->key_base > 6 && 4 == _i % _ctx->key->key_base )
+		{
+			for( _j = 0; _j < OAES_COL_LEN; _j++ )
+				oaes_sub_byte( _temp + _j );
+		}
+		
+		for( _j = 0; _j < OAES_COL_LEN; _j++ )
+		{
+			_ctx->key->exp_data[ _i * OAES_RKEY_LEN + _j ] =
+					_ctx->key->exp_data[ ( _i - _ctx->key->key_base ) *
+					OAES_RKEY_LEN + _j ] ^ _temp[_j];
+		}
+	}
+	
+	return OAES_RET_SUCCESS;
+}
+
+static OAES_RET oaes_key_gen( OAES_CTX * ctx, size_t key_size )
+{
+	size_t _i;
+	oaes_key * _key = NULL;
+	oaes_ctx * _ctx = (oaes_ctx *) ctx;
+	OAES_RET _rc = OAES_RET_SUCCESS;
+	
+	if( NULL == _ctx )
+		return OAES_RET_ARG1;
+	
+	_key = (oaes_key *) calloc( sizeof( oaes_key ), 1 );
+	
+	if( NULL == _key )
+		return OAES_RET_MEM;
+	
+	if( _ctx->key )
+		oaes_key_destroy( &(_ctx->key) );
+	
+	_key->data_len = key_size;
+	_key->data = (uint8_t *) calloc( key_size, sizeof( uint8_t ));
+	
+	if( NULL == _key->data )
+		return OAES_RET_MEM;
+	
+	for( _i = 0; _i < key_size; _i++ )
+#ifdef OAES_HAVE_ISAAC
+		_key->data[_i] = (uint8_t) rand( _ctx->rctx );
+#else
+		_key->data[_i] = (uint8_t) rand();
+#endif // OAES_HAVE_ISAAC
+	
+	_ctx->key = _key;
+	_rc = _rc || oaes_key_expand( ctx );
+	
+	if( _rc != OAES_RET_SUCCESS )
+	{
+		oaes_key_destroy( &(_ctx->key) );
+		return _rc;
+	}
+	
+	return OAES_RET_SUCCESS;
+}
+
+OAES_RET oaes_key_gen_128( OAES_CTX * ctx )
+{
+	return oaes_key_gen( ctx, 16 );
+}
+
+OAES_RET oaes_key_gen_192( OAES_CTX * ctx )
+{
+	return oaes_key_gen( ctx, 24 );
+}
+
+OAES_RET oaes_key_gen_256( OAES_CTX * ctx )
+{
+	return oaes_key_gen( ctx, 32 );
+}
+
+OAES_RET oaes_key_export( OAES_CTX * ctx,
+		uint8_t * data, size_t * data_len )
+{
+	size_t _data_len_in;
+	oaes_ctx * _ctx = (oaes_ctx *) ctx;
+	
+	if( NULL == _ctx )
+		return OAES_RET_ARG1;
+	
+	if( NULL == _ctx->key )
+		return OAES_RET_NOKEY;
+	
+	if( NULL == data_len )
+		return OAES_RET_ARG3;
+
+	_data_len_in = *data_len;
+	// data + header
+	*data_len = _ctx->key->data_len + OAES_BLOCK_SIZE;
+
+	if( NULL == data )
+		return OAES_RET_SUCCESS;
+	
+	if( _data_len_in < *data_len )
+		return OAES_RET_BUF;
+	
+	// header
+	memcpy( data, oaes_header, OAES_BLOCK_SIZE );
+	data[5] = 0x01;
+	data[7] = _ctx->key->data_len;
+	memcpy( data + OAES_BLOCK_SIZE, _ctx->key->data, _ctx->key->data_len );
+	
+	return OAES_RET_SUCCESS;
+}
+
+OAES_RET oaes_key_export_data( OAES_CTX * ctx,
+		uint8_t * data, size_t * data_len )
+{
+	size_t _data_len_in;
+	oaes_ctx * _ctx = (oaes_ctx *) ctx;
+	
+	if( NULL == _ctx )
+		return OAES_RET_ARG1;
+	
+	if( NULL == _ctx->key )
+		return OAES_RET_NOKEY;
+	
+	if( NULL == data_len )
+		return OAES_RET_ARG3;
+
+	_data_len_in = *data_len;
+	*data_len = _ctx->key->data_len;
+
+	if( NULL == data )
+		return OAES_RET_SUCCESS;
+	
+	if( _data_len_in < *data_len )
+		return OAES_RET_BUF;
+	
+	memcpy( data, _ctx->key->data, *data_len );
+	
+	return OAES_RET_SUCCESS;
+}
+
+OAES_RET oaes_key_import( OAES_CTX * ctx,
+		const uint8_t * data, size_t data_len )
+{
+	oaes_ctx * _ctx = (oaes_ctx *) ctx;
+	OAES_RET _rc = OAES_RET_SUCCESS;
+	int _key_length;
+	
+	if( NULL == _ctx )
+		return OAES_RET_ARG1;
+	
+	if( NULL == data )
+		return OAES_RET_ARG2;
+	
+	switch( data_len )
+	{
+		case 16 + OAES_BLOCK_SIZE:
+		case 24 + OAES_BLOCK_SIZE:
+		case 32 + OAES_BLOCK_SIZE:
+			break;
+		default:
+			return OAES_RET_ARG3;
+	}
+	
+	// header
+	if( 0 != memcmp( data, oaes_header, 4 ) )
+		return OAES_RET_HEADER;
+
+	// header version
+	switch( data[4] )
+	{
+		case 0x01:
+			break;
+		default:
+			return OAES_RET_HEADER;
+	}
+	
+	// header type
+	switch( data[5] )
+	{
+		case 0x01:
+			break;
+		default:
+			return OAES_RET_HEADER;
+	}
+	
+	// options
+	_key_length = data[7];
+	switch( _key_length )
+	{
+		case 16:
+		case 24:
+		case 32:
+			break;
+		default:
+			return OAES_RET_HEADER;
+	}
+	
+	if( data_len != _key_length + OAES_BLOCK_SIZE )
+			return OAES_RET_ARG3;
+	
+	if( _ctx->key )
+		oaes_key_destroy( &(_ctx->key) );
+	
+	_ctx->key = (oaes_key *) calloc( sizeof( oaes_key ), 1 );
+	
+	if( NULL == _ctx->key )
+		return OAES_RET_MEM;
+	
+	_ctx->key->data_len = _key_length;
+	_ctx->key->data = (uint8_t *)
+			calloc( _key_length, sizeof( uint8_t ));
+	
+	if( NULL == _ctx->key->data )
+	{
+		oaes_key_destroy( &(_ctx->key) );
+		return OAES_RET_MEM;
+	}
+
+	memcpy( _ctx->key->data, data + OAES_BLOCK_SIZE, _key_length );
+	_rc = _rc || oaes_key_expand( ctx );
+	
+	if( _rc != OAES_RET_SUCCESS )
+	{
+		oaes_key_destroy( &(_ctx->key) );
+		return _rc;
+	}
+	
+	return OAES_RET_SUCCESS;
+}
+
+OAES_RET oaes_key_import_data( OAES_CTX * ctx,
+		const uint8_t * data, size_t data_len )
+{
+	oaes_ctx * _ctx = (oaes_ctx *) ctx;
+	OAES_RET _rc = OAES_RET_SUCCESS;
+	
+	if( NULL == _ctx )
+		return OAES_RET_ARG1;
+	
+	if( NULL == data )
+		return OAES_RET_ARG2;
+	
+	switch( data_len )
+	{
+		case 16:
+		case 24:
+		case 32:
+			break;
+		default:
+			return OAES_RET_ARG3;
+	}
+	
+	if( _ctx->key )
+		oaes_key_destroy( &(_ctx->key) );
+	
+	_ctx->key = (oaes_key *) calloc( sizeof( oaes_key ), 1 );
+	
+	if( NULL == _ctx->key )
+		return OAES_RET_MEM;
+	
+	_ctx->key->data_len = data_len;
+	_ctx->key->data = (uint8_t *)
+			calloc( data_len, sizeof( uint8_t ));
+	
+	if( NULL == _ctx->key->data )
+	{
+		oaes_key_destroy( &(_ctx->key) );
+		return OAES_RET_MEM;
+	}
+
+	memcpy( _ctx->key->data, data, data_len );
+	_rc = _rc || oaes_key_expand( ctx );
+	
+	if( _rc != OAES_RET_SUCCESS )
+	{
+		oaes_key_destroy( &(_ctx->key) );
+		return _rc;
+	}
+	
+	return OAES_RET_SUCCESS;
+}
+
+OAES_CTX * oaes_alloc()
+{
+	oaes_ctx * _ctx = (oaes_ctx *) calloc( sizeof( oaes_ctx ), 1 );
+	
+	if( NULL == _ctx )
+		return NULL;
+
+#ifdef OAES_HAVE_ISAAC
+	{
+	  ub4 _i = 0;
+		char _seed[RANDSIZ + 1];
+		
+		_ctx->rctx = (randctx *) calloc( sizeof( randctx ), 1 );
+
+		if( NULL == _ctx->rctx )
+		{
+			free( _ctx );
+			return NULL;
+		}
+
+		oaes_get_seed( _seed );
+		memset( _ctx->rctx->randrsl, 0, RANDSIZ );
+		memcpy( _ctx->rctx->randrsl, _seed, RANDSIZ );
+		randinit( _ctx->rctx, TRUE);
+	}
+#else
+		srand( oaes_get_seed() );
+#endif // OAES_HAVE_ISAAC
+
+	_ctx->key = NULL;
+	oaes_set_option( _ctx, OAES_OPTION_CBC, NULL );
+
+#ifdef OAES_DEBUG
+	_ctx->step_cb = NULL;
+	oaes_set_option( _ctx, OAES_OPTION_STEP_OFF, NULL );
+#endif // OAES_DEBUG
+
+	return (OAES_CTX *) _ctx;
+}
+
+OAES_RET oaes_free( OAES_CTX ** ctx )
+{
+	oaes_ctx ** _ctx = (oaes_ctx **) ctx;
+
+	if( NULL == _ctx )
+		return OAES_RET_ARG1;
+	
+	if( NULL == *_ctx )
+		return OAES_RET_SUCCESS;
+	
+	if( (*_ctx)->key )
+		oaes_key_destroy( &((*_ctx)->key) );
+
+#ifdef OAES_HAVE_ISAAC
+	if( (*_ctx)->rctx )
+	{
+		free( (*_ctx)->rctx );
+		(*_ctx)->rctx = NULL;
+	}
+#endif // OAES_HAVE_ISAAC
+	
+	free( *_ctx );
+	*_ctx = NULL;
+
+	return OAES_RET_SUCCESS;
+}
+
+OAES_RET oaes_set_option( OAES_CTX * ctx,
+		OAES_OPTION option, const void * value )
+{
+	size_t _i;
+	oaes_ctx * _ctx = (oaes_ctx *) ctx;
+	
+	if( NULL == _ctx )
+		return OAES_RET_ARG1;
+
+	switch( option )
+	{
+		case OAES_OPTION_ECB:
+			_ctx->options &= ~OAES_OPTION_CBC;
+			memset( _ctx->iv, 0, OAES_BLOCK_SIZE );
+			break;
+
+		case OAES_OPTION_CBC:
+			_ctx->options &= ~OAES_OPTION_ECB;
+			if( value )
+				memcpy( _ctx->iv, value, OAES_BLOCK_SIZE );
+			else
+			{
+				for( _i = 0; _i < OAES_BLOCK_SIZE; _i++ )
+#ifdef OAES_HAVE_ISAAC
+					_ctx->iv[_i] = (uint8_t) rand( _ctx->rctx );
+#else
+					_ctx->iv[_i] = (uint8_t) rand();
+#endif // OAES_HAVE_ISAAC
+			}
+			break;
+
+#ifdef OAES_DEBUG
+
+		case OAES_OPTION_STEP_ON:
+			if( value )
+			{
+				_ctx->options &= ~OAES_OPTION_STEP_OFF;
+				_ctx->step_cb = value;
+			}
+			else
+			{
+				_ctx->options &= ~OAES_OPTION_STEP_ON;
+				_ctx->options |= OAES_OPTION_STEP_OFF;
+				_ctx->step_cb = NULL;
+				return OAES_RET_ARG3;
+			}
+			break;
+
+		case OAES_OPTION_STEP_OFF:
+			_ctx->options &= ~OAES_OPTION_STEP_ON;
+			_ctx->step_cb = NULL;
+			break;
+
+#endif // OAES_DEBUG
+
+		default:
+			return OAES_RET_ARG2;
+	}
+
+	_ctx->options |= option;
+
+	return OAES_RET_SUCCESS;
+}
+
+static OAES_RET oaes_encrypt_block(
+		OAES_CTX * ctx, uint8_t * c, size_t c_len )
+{
+	size_t _i, _j;
+	oaes_ctx * _ctx = (oaes_ctx *) ctx;
+	
+	if( NULL == _ctx )
+		return OAES_RET_ARG1;
+	
+	if( NULL == c )
+		return OAES_RET_ARG2;
+	
+	if( c_len != OAES_BLOCK_SIZE )
+		return OAES_RET_ARG3;
+	
+	if( NULL == _ctx->key )
+		return OAES_RET_NOKEY;
+	
+#ifdef OAES_DEBUG
+	if( _ctx->step_cb )
+		_ctx->step_cb( c, "input", 1, NULL );
+#endif // OAES_DEBUG
+
+	// AddRoundKey(State, K0)
+	for( _i = 0; _i < c_len; _i++ )
+		c[_i] = c[_i] ^ _ctx->key->exp_data[_i];
+	
+#ifdef OAES_DEBUG
+	if( _ctx->step_cb )
+	{
+		_ctx->step_cb( _ctx->key->exp_data, "k_sch", 1, NULL );
+		_ctx->step_cb( c, "k_add", 1, NULL );
+	}
+#endif // OAES_DEBUG
+
+	// for round = 1 step 1 to Nr–1
+	for( _i = 1; _i < _ctx->key->num_keys - 1; _i++ )
+	{
+		// SubBytes(state)
+		for( _j = 0; _j < c_len; _j++ )
+			oaes_sub_byte( c + _j );
+
+#ifdef OAES_DEBUG
+		if( _ctx->step_cb )
+			_ctx->step_cb( c, "s_box", _i, NULL );
+#endif // OAES_DEBUG
+
+		// ShiftRows(state)
+		oaes_shift_rows( c );
+		
+#ifdef OAES_DEBUG
+		if( _ctx->step_cb )
+			_ctx->step_cb( c, "s_row", _i, NULL );
+#endif // OAES_DEBUG
+
+		// MixColumns(state)
+		oaes_mix_cols( c );
+		oaes_mix_cols( c + 4 );
+		oaes_mix_cols( c + 8 );
+		oaes_mix_cols( c + 12 );
+		
+#ifdef OAES_DEBUG
+		if( _ctx->step_cb )
+			_ctx->step_cb( c, "m_col", _i, NULL );
+#endif // OAES_DEBUG
+
+		// AddRoundKey(state, w[round*Nb, (round+1)*Nb-1])
+		for( _j = 0; _j < c_len; _j++ )
+			c[_j] = c[_j] ^
+					_ctx->key->exp_data[_i * OAES_RKEY_LEN * OAES_COL_LEN + _j];
+
+#ifdef OAES_DEBUG
+	if( _ctx->step_cb )
+	{
+		_ctx->step_cb( _ctx->key->exp_data + _i * OAES_RKEY_LEN * OAES_COL_LEN,
+				"k_sch", _i, NULL );
+		_ctx->step_cb( c, "k_add", _i, NULL );
+	}
+#endif // OAES_DEBUG
+
+	}
+	
+	// SubBytes(state)
+	for( _i = 0; _i < c_len; _i++ )
+		oaes_sub_byte( c + _i );
+	
+#ifdef OAES_DEBUG
+	if( _ctx->step_cb )
+		_ctx->step_cb( c, "s_box", _ctx->key->num_keys - 1, NULL );
+#endif // OAES_DEBUG
+
+	// ShiftRows(state)
+	oaes_shift_rows( c );
+
+#ifdef OAES_DEBUG
+	if( _ctx->step_cb )
+		_ctx->step_cb( c, "s_row", _ctx->key->num_keys - 1, NULL );
+#endif // OAES_DEBUG
+
+	// AddRoundKey(state, w[Nr*Nb, (Nr+1)*Nb-1])
+	for( _i = 0; _i < c_len; _i++ )
+		c[_i] = c[_i] ^ _ctx->key->exp_data[
+				( _ctx->key->num_keys - 1 ) * OAES_RKEY_LEN * OAES_COL_LEN + _i ];
+
+#ifdef OAES_DEBUG
+	if( _ctx->step_cb )
+	{
+		_ctx->step_cb( _ctx->key->exp_data +
+				( _ctx->key->num_keys - 1 ) * OAES_RKEY_LEN * OAES_COL_LEN,
+				"k_sch", _ctx->key->num_keys - 1, NULL );
+		_ctx->step_cb( c, "output", _ctx->key->num_keys - 1, NULL );
+	}
+#endif // OAES_DEBUG
+
+	return OAES_RET_SUCCESS;
+}
+
+static OAES_RET oaes_decrypt_block(
+		OAES_CTX * ctx, uint8_t * c, size_t c_len )
+{
+	size_t _i, _j;
+	oaes_ctx * _ctx = (oaes_ctx *) ctx;
+	
+	if( NULL == _ctx )
+		return OAES_RET_ARG1;
+	
+	if( NULL == c )
+		return OAES_RET_ARG2;
+	
+	if( c_len != OAES_BLOCK_SIZE )
+		return OAES_RET_ARG3;
+	
+	if( NULL == _ctx->key )
+		return OAES_RET_NOKEY;
+	
+#ifdef OAES_DEBUG
+	if( _ctx->step_cb )
+		_ctx->step_cb( c, "iinput", _ctx->key->num_keys - 1, NULL );
+#endif // OAES_DEBUG
+
+	// AddRoundKey(state, w[Nr*Nb, (Nr+1)*Nb-1])
+	for( _i = 0; _i < c_len; _i++ )
+		c[_i] = c[_i] ^ _ctx->key->exp_data[
+				( _ctx->key->num_keys - 1 ) * OAES_RKEY_LEN * OAES_COL_LEN + _i ];
+
+#ifdef OAES_DEBUG
+	if( _ctx->step_cb )
+	{
+		_ctx->step_cb( _ctx->key->exp_data +
+				( _ctx->key->num_keys - 1 ) * OAES_RKEY_LEN * OAES_COL_LEN,
+				"ik_sch", _ctx->key->num_keys - 1, NULL );
+		_ctx->step_cb( c, "ik_add", _ctx->key->num_keys - 1, NULL );
+	}
+#endif // OAES_DEBUG
+
+	for( _i = _ctx->key->num_keys - 2; _i > 0; _i-- )
+	{
+		// InvShiftRows(state)
+		oaes_inv_shift_rows( c );
+
+#ifdef OAES_DEBUG
+	if( _ctx->step_cb )
+		_ctx->step_cb( c, "is_row", _i, NULL );
+#endif // OAES_DEBUG
+
+		// InvSubBytes(state)
+		for( _j = 0; _j < c_len; _j++ )
+			oaes_inv_sub_byte( c + _j );
+	
+#ifdef OAES_DEBUG
+	if( _ctx->step_cb )
+		_ctx->step_cb( c, "is_box", _i, NULL );
+#endif // OAES_DEBUG
+
+		// AddRoundKey(state, w[round*Nb, (round+1)*Nb-1])
+		for( _j = 0; _j < c_len; _j++ )
+			c[_j] = c[_j] ^
+					_ctx->key->exp_data[_i * OAES_RKEY_LEN * OAES_COL_LEN + _j];
+		
+#ifdef OAES_DEBUG
+	if( _ctx->step_cb )
+	{
+		_ctx->step_cb( _ctx->key->exp_data + _i * OAES_RKEY_LEN * OAES_COL_LEN,
+				"ik_sch", _i, NULL );
+		_ctx->step_cb( c, "ik_add", _i, NULL );
+	}
+#endif // OAES_DEBUG
+
+		// InvMixColums(state)
+		oaes_inv_mix_cols( c );
+		oaes_inv_mix_cols( c + 4 );
+		oaes_inv_mix_cols( c + 8 );
+		oaes_inv_mix_cols( c + 12 );
+
+#ifdef OAES_DEBUG
+	if( _ctx->step_cb )
+		_ctx->step_cb( c, "im_col", _i, NULL );
+#endif // OAES_DEBUG
+
+	}
+
+	// InvShiftRows(state)
+	oaes_inv_shift_rows( c );
+
+#ifdef OAES_DEBUG
+	if( _ctx->step_cb )
+		_ctx->step_cb( c, "is_row", 1, NULL );
+#endif // OAES_DEBUG
+
+	// InvSubBytes(state)
+	for( _i = 0; _i < c_len; _i++ )
+		oaes_inv_sub_byte( c + _i );
+
+#ifdef OAES_DEBUG
+	if( _ctx->step_cb )
+		_ctx->step_cb( c, "is_box", 1, NULL );
+#endif // OAES_DEBUG
+
+	// AddRoundKey(state, w[0, Nb-1])
+	for( _i = 0; _i < c_len; _i++ )
+		c[_i] = c[_i] ^ _ctx->key->exp_data[_i];
+	
+#ifdef OAES_DEBUG
+	if( _ctx->step_cb )
+	{
+		_ctx->step_cb( _ctx->key->exp_data, "ik_sch", 1, NULL );
+		_ctx->step_cb( c, "ioutput", 1, NULL );
+	}
+#endif // OAES_DEBUG
+
+	return OAES_RET_SUCCESS;
+}
+
+OAES_RET oaes_encrypt( OAES_CTX * ctx,
+		const uint8_t * m, size_t m_len, uint8_t * c, size_t * c_len )
+{
+	size_t _i, _j, _c_len_in, _c_data_len;
+	size_t _pad_len = m_len % OAES_BLOCK_SIZE == 0 ?
+			0 : OAES_BLOCK_SIZE - m_len % OAES_BLOCK_SIZE;
+	oaes_ctx * _ctx = (oaes_ctx *) ctx;
+	OAES_RET _rc = OAES_RET_SUCCESS;
+	uint8_t _flags = _pad_len ? OAES_FLAG_PAD : 0;
+	
+	if( NULL == _ctx )
+		return OAES_RET_ARG1;
+	
+	if( NULL == m )
+		return OAES_RET_ARG2;
+	
+	if( NULL == c_len )
+		return OAES_RET_ARG5;
+	
+	_c_len_in = *c_len;
+	// data + pad
+	_c_data_len = m_len + _pad_len;
+	// header + iv + data + pad
+	*c_len = 2 * OAES_BLOCK_SIZE + m_len + _pad_len;
+
+	if( NULL == c )
+		return OAES_RET_SUCCESS;
+	
+	if( _c_len_in < *c_len )
+		return OAES_RET_BUF;
+	
+	if( NULL == _ctx->key )
+		return OAES_RET_NOKEY;
+	
+	// header
+	memcpy(c, oaes_header, OAES_BLOCK_SIZE );
+	memcpy(c + 6, &_ctx->options, sizeof(_ctx->options));
+	memcpy(c + 8, &_flags, sizeof(_flags));
+	// iv
+	memcpy(c + OAES_BLOCK_SIZE, _ctx->iv, OAES_BLOCK_SIZE );
+	// data
+	memcpy(c + 2 * OAES_BLOCK_SIZE, m, m_len );
+	
+	for( _i = 0; _i < _c_data_len; _i += OAES_BLOCK_SIZE )
+	{
+		uint8_t _block[OAES_BLOCK_SIZE];
+		size_t _block_size = min( m_len - _i, OAES_BLOCK_SIZE );
+
+		memcpy( _block, c + 2 * OAES_BLOCK_SIZE + _i, _block_size );
+		
+		// insert pad
+		for( _j = 0; _j < OAES_BLOCK_SIZE - _block_size; _j++ )
+			_block[ _block_size + _j ] = _j + 1;
+	
+		// CBC
+		if( _ctx->options & OAES_OPTION_CBC )
+		{
+			for( _j = 0; _j < OAES_BLOCK_SIZE; _j++ )
+				_block[_j] = _block[_j] ^ _ctx->iv[_j];
+		}
+
+		_rc = _rc ||
+				oaes_encrypt_block( ctx, _block, OAES_BLOCK_SIZE );
+		memcpy( c + 2 * OAES_BLOCK_SIZE + _i, _block, OAES_BLOCK_SIZE );
+		
+		if( _ctx->options & OAES_OPTION_CBC )
+			memcpy( _ctx->iv, _block, OAES_BLOCK_SIZE );
+	}
+	
+	return _rc;
+}
+
+OAES_RET oaes_decrypt( OAES_CTX * ctx,
+		const uint8_t * c, size_t c_len, uint8_t * m, size_t * m_len )
+{
+	size_t _i, _j, _m_len_in;
+	oaes_ctx * _ctx = (oaes_ctx *) ctx;
+	OAES_RET _rc = OAES_RET_SUCCESS;
+	uint8_t _iv[OAES_BLOCK_SIZE];
+	uint8_t _flags;
+	OAES_OPTION _options;
+	
+	if( NULL == ctx )
+		return OAES_RET_ARG1;
+	
+	if( NULL == c )
+		return OAES_RET_ARG2;
+	
+	if( c_len % OAES_BLOCK_SIZE )
+		return OAES_RET_ARG3;
+	
+	if( NULL == m_len )
+		return OAES_RET_ARG5;
+	
+	_m_len_in = *m_len;
+	*m_len = c_len - 2 * OAES_BLOCK_SIZE;
+	
+	if( NULL == m )
+		return OAES_RET_SUCCESS;
+	
+	if( _m_len_in < *m_len )
+		return OAES_RET_BUF;
+	
+	if( NULL == _ctx->key )
+		return OAES_RET_NOKEY;
+	
+	// header
+	if( 0 != memcmp( c, oaes_header, 4 ) )
+		return OAES_RET_HEADER;
+
+	// header version
+	switch( c[4] )
+	{
+		case 0x01:
+			break;
+		default:
+			return OAES_RET_HEADER;
+	}
+	
+	// header type
+	switch( c[5] )
+	{
+		case 0x02:
+			break;
+		default:
+			return OAES_RET_HEADER;
+	}
+	
+	// options
+	memcpy(&_options, c + 6, sizeof(_options));
+	// validate that all options are valid
+	if( _options & ~(
+			  OAES_OPTION_ECB
+			| OAES_OPTION_CBC
+#ifdef OAES_DEBUG
+			| OAES_OPTION_STEP_ON
+			| OAES_OPTION_STEP_OFF
+#endif // OAES_DEBUG
+			) )
+		return OAES_RET_HEADER;
+	if( ( _options & OAES_OPTION_ECB ) &&
+			( _options & OAES_OPTION_CBC ) )
+		return OAES_RET_HEADER;
+	if( _options == OAES_OPTION_NONE )
+		return OAES_RET_HEADER;
+	
+	// flags
+	memcpy(&_flags, c + 8, sizeof(_flags));
+	// validate that all flags are valid
+	if( _flags & ~(
+			  OAES_FLAG_PAD
+			) )
+		return OAES_RET_HEADER;
+
+	// iv
+	memcpy( _iv, c + OAES_BLOCK_SIZE, OAES_BLOCK_SIZE);
+	// data + pad
+	memcpy( m, c + 2 * OAES_BLOCK_SIZE, *m_len );
+	
+	for( _i = 0; _i < *m_len; _i += OAES_BLOCK_SIZE )
+	{
+		if( ( _options & OAES_OPTION_CBC ) && _i > 0 )
+			memcpy( _iv, c + OAES_BLOCK_SIZE + _i, OAES_BLOCK_SIZE );
+		
+		_rc = _rc ||
+				oaes_decrypt_block( ctx, m + _i, min( *m_len - _i, OAES_BLOCK_SIZE ) );
+		
+		// CBC
+		if( _options & OAES_OPTION_CBC )
+		{
+			for( _j = 0; _j < OAES_BLOCK_SIZE; _j++ )
+				m[ _i + _j ] = m[ _i + _j ] ^ _iv[_j];
+		}
+	}
+	
+	// remove pad
+	if( _flags & OAES_FLAG_PAD )
+	{
+		int _is_pad = 1;
+		size_t _temp = (size_t) m[*m_len - 1];
+
+		if( _temp  <= 0x00 || _temp > 0x0f )
+			return OAES_RET_HEADER;
+		for( _i = 0; _i < _temp; _i++ )
+			if( m[*m_len - 1 - _i] != _temp - _i )
+				_is_pad = 0;
+		if( _is_pad )
+		{
+			memset( m + *m_len - _temp, 0, _temp );
+			*m_len -= _temp;
+		}
+		else
+			return OAES_RET_HEADER;
+	}
+	
+	return OAES_RET_SUCCESS;
+}