///////////////////////////////////////////////////////////////////////////////
// ÎÄ ¼þ Ãû£ºTH_AES.cpp
// Ãè    Êö£ºAES¼ÓÃÜËã·¨
///////////////////////////////////////////////////////////////////////////////

#include <string.h>

#include "TH_AES.h"

// ¼Ó½âÃÜģʽ
#define AES_MODE_ECB	0				// µç×ÓÃÜÂ뱾ģʽ£¨Ò»°ãģʽ£©
#define AES_MODE_CBC	1				// ÃÜÂë·Ö×éÁ´½Óģʽ
#define AES_MODE		AES_MODE_CBC

#define Nk	(AES_KEY_LEN / 4)	// ÒÔ4×Ö½ÚΪµ¥Î»µÄÃÜÔ¿³¤¶È
#define Nb	4					// ÒÔ4×Ö½ÚΪµ¥Î»µÄ¼Ó½âÃÜÊý¾Ý¿é´óС£¬¹Ì¶¨Îª4

// Nr£º¼ÓÃܵÄÂÖÊý
#if   AES_KEY_LEN == 16
	#define Nr	10
#elif AES_KEY_LENGTH == 24
	#define Nr	12
#elif AES_KEY_LENGTH == 32
	#define Nr	14
#else
	#error AES_KEY_LEN must be 16, 24 or 32 bytes !
#endif

// ¼ÓÃÜÓõÄSBox
static const unsigned char 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 
};

// ½âÃÜÓõÄSBox
static const unsigned char InvSBox[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	
};

// CBCģʽ³õʼ»¯ÏòÁ¿
static const unsigned char IV[32] = { 0x00 };

///////////////////////////////////////////////////////////////////////////////
//	º¯ÊýÃû£º	RotationWord
//	ÃèÊö£º		¶ÔÒ»¸ö¡°×Ö¡±Êý¾Ý½øÐÐÑ­»·ÓÒÒÆ¡£
//	ÊäÈë²ÎÊý£º	pWord -- ÒªÓÒÒƵÄ4×Ö½ÚÊý¾Ý¡£
//	Êä³ö²ÎÊý£º	pWord -- ÓÒÒƺóµÄ4×Ö½ÚÊý¾Ý¡£
//	·µ»ØÖµ£º	ÎÞ¡£
///////////////////////////////////////////////////////////////////////////////
static void RotationWord(unsigned char *pWord)
{
	unsigned char temp = pWord[0];
	pWord[0]  = pWord[1];
	pWord[1]  = pWord[2];
	pWord[2]  = pWord[3];
	pWord[3]  = temp;
}

///////////////////////////////////////////////////////////////////////////////
//	º¯ÊýÃû£º	XorBytes
//	ÃèÊö£º		ÅúÁ¿Òì»òÁ½×éÊý¾Ý¡£
//	ÊäÈë²ÎÊý£º	pData1 -- ÒªÒì»òµÄµÚÒ»×éÊý¾Ý¡£
//				pData1 -- ÒªÒì»òµÄµÚ¶þ×éÊý¾Ý¡£
//				nCount -- ÒªÒì»òµÄÊý¾Ý³¤¶È¡£
//	Êä³ö²ÎÊý£º	pData1 -- Òì»òºóµÄ½á¹û¡£
//	·µ»ØÖµ£º	ÎÞ¡£
///////////////////////////////////////////////////////////////////////////////
static void XorBytes(unsigned char *pData1, const unsigned char *pData2, unsigned char nCount)
{
	unsigned char i;
	for(i = 0; i < nCount; i++) pData1[i] ^= pData2[i];
}

///////////////////////////////////////////////////////////////////////////////
//	º¯ÊýÃû£º	AddRoundKey
//	ÃèÊö£º		°Ñ Öмä״̬Êý¾Ý ¼ÓÉÏ£¨Òì»ò£©×ÓÃÜÔ¿£¬Êý¾Ý³¤¶ÈΪ16×Ö½Ú¡£
//	ÊäÈë²ÎÊý£º	pState	  -- ״̬Êý¾Ý¡£
//				pRoundKey -- ×ÓÃÜÔ¿Êý¾Ý¡£
//	Êä³ö²ÎÊý£º	pState	  -- ¼ÓÉÏ×ÓÃÜÔ¿ºóµÄ״̬Êý¾Ý¡£
//	·µ»ØÖµ£º	ÎÞ¡£
///////////////////////////////////////////////////////////////////////////////
// static void AddRoundKey(unsigned char *pState, const unsigned char *pRoundKey)
// {
// 	XorBytes(pState, pRoundKey, 4*Nb);
// }

// AddRoundKeyµÄºêÐÎʽ£¬±Èº¯ÊýÐÎʽ¿ÉÒÔ½ÚÊ¡4×Ö½ÚµÄdataÊý¾Ý
#define AddRoundKey(pState, pRoundKey) \
	XorBytes((pState), (pRoundKey), 4 * Nb)


///////////////////////////////////////////////////////////////////////////////
//	º¯ÊýÃû£º	SubBytes
//	ÃèÊö£º		ͨ¹ýSºÐ×ÓÖû»×´Ì¬Êý¾Ý¡£
//	ÊäÈë²ÎÊý£º	pState	-- ״̬Êý¾Ý¡£
//				nCount  -- ״̬Êý¾Ý³¤¶È¡£
//				bInvert	-- ÊÇ·ñʹÓ÷´ÏòSºÐ×Ó£¨½âÃÜʱʹÓã©¡£
//	Êä³ö²ÎÊý£º	pState	-- Öû»ºóµÄ״̬Êý¾Ý¡£
//	·µ»ØÖµ£º	ÎÞ¡£
///////////////////////////////////////////////////////////////////////////////
static void SubBytes(unsigned char *pState, unsigned char nCount, unsigned char bInvert)
{
	const unsigned char *pSBox = bInvert ? InvSBox : SBox;
	unsigned char i;
	for (i = 0; i < nCount; i++) pState[i] = pSBox[pState[i]];
}

///////////////////////////////////////////////////////////////////////////////
//	º¯ÊýÃû£º	ShiftRows
//	ÃèÊö£º		°Ñ״̬Êý¾ÝÒÆÐС£
//	ÊäÈë²ÎÊý£º	pState	-- ״̬Êý¾Ý¡£
//				bInvert	-- ÊÇ·ñ·´ÏòÒÆÐУ¨½âÃÜʱʹÓã©¡£
//	Êä³ö²ÎÊý£º	pState	-- ÒÆÐкóµÄ״̬Êý¾Ý¡£
//	·µ»ØÖµ£º	ÎÞ¡£
///////////////////////////////////////////////////////////////////////////////
static void ShiftRows(unsigned char *pState, unsigned char bInvert)
{
	// ×¢Ò⣺״̬Êý¾ÝÒÔÁÐÐÎʽ´æ·Å£¡

	unsigned char r, c;	// ÐУ¬ÁÐ
	unsigned char temp, rowData[4];
	
	for (r = 1; r < 4; r++) {
		// ±¸·ÝÒ»ÐÐÊý¾Ý
		for (c = 0; c < 4; c++) rowData[c] = pState[r + 4 * c];

		temp = bInvert ? (4 - r) : r;
		for (c = 0; c < 4; c++) pState[r + 4 * c] = rowData[(c + temp) % 4];
	}
}

///////////////////////////////////////////////////////////////////////////////
//	º¯ÊýÃû£º	GfMultBy02
//	ÃèÊö£º		ÔÚGF(28)ÓòµÄ ³Ë2 ÔËËã¡£
//	ÊäÈë²ÎÊý£º	num	-- ³ËÊý¡£
//	Êä³ö²ÎÊý£º	ÎÞ¡£
//	·µ»ØÖµ£º	num³ËÒÔ2µÄ½á¹û¡£
///////////////////////////////////////////////////////////////////////////////
static unsigned char GfMultBy02(unsigned char num)
{
#define BPOLY 0x1B // GF(28) ¶àÏîʽ: Lower 8 BOOLs of (x^8 + x^4 + x^3 + x + 1), ie. (x^4 + x^3 + x + 1).

	if ((num & 0x80) == 0) num = num << 1;
	else num = (num << 1) ^ BPOLY;
	
	return num;
}

///////////////////////////////////////////////////////////////////////////////
//	º¯ÊýÃû£º	MixColumns
//	ÃèÊö£º		»ìºÏ״̬¸÷ÁÐÊý¾Ý¡£
//	ÊäÈë²ÎÊý£º	pState	-- ״̬Êý¾Ý¡£
//				bInvert	-- ÊÇ·ñ·´Ïò»ìºÏ£¨½âÃÜʱʹÓã©¡£
//	Êä³ö²ÎÊý£º	pState	-- »ìºÏÁкóµÄ״̬Êý¾Ý¡£
//	·µ»ØÖµ£º	ÎÞ¡£
///////////////////////////////////////////////////////////////////////////////
static void MixColumns(unsigned char *pState, unsigned char bInvert)
{
	unsigned char i, temp;
	unsigned char a0Pa2_M4;	// 4(a0 + a2)
	unsigned char a1Pa3_M4;	// 4(a1 + a3)
	unsigned char result[4];

	for (i = 0; i < 4; i++, pState += 4) {
		// b0 = 2a0 + 3a1 + a2 + a3 
		//    = (a0 + a1 + a2 + a3) + 2(a0 + a1) + a0

		temp = pState[0] ^ pState[1] ^ pState[2] ^ pState[3];
		result[0] = temp ^ pState[0] ^ GfMultBy02((unsigned char) (pState[0] ^ pState[1]));
		result[1] = temp ^ pState[1] ^ GfMultBy02((unsigned char) (pState[1] ^ pState[2]));
		result[2] = temp ^ pState[2] ^ GfMultBy02((unsigned char) (pState[2] ^ pState[3]));
		result[3] = temp ^ pState[3] ^ GfMultBy02((unsigned char) (pState[3] ^ pState[0]));

		if (bInvert) {
			// b0' = 14a0 + 11a1 + 13a2 + 9a3 
			//     = (a0 + a1 + a2 + a3) + 2(a0 + a1) + a0	£¨Õⲿ·ÖΪb0£©
			//       + 2(4(a0 + a2) + 4(a1 + a3))
			//       +   4(a0 + a2)

			a0Pa2_M4 = GfMultBy02(GfMultBy02((unsigned char) (pState[0] ^ pState[2])));
			a1Pa3_M4 = GfMultBy02(GfMultBy02((unsigned char) (pState[1] ^ pState[3])));
			temp	 = GfMultBy02((unsigned char) (a0Pa2_M4 ^ a1Pa3_M4));
			result[0] ^= temp ^ a0Pa2_M4;
			result[1] ^= temp ^ a1Pa3_M4;
			result[2] ^= temp ^ a0Pa2_M4;
			result[3] ^= temp ^ a1Pa3_M4;
		}

		memcpy(pState, result, 4);
	}
}

///////////////////////////////////////////////////////////////////////////////
//	º¯ÊýÃû£º	BlockEncrypt
//	ÃèÊö£º		¶Ôµ¥¿éÊý¾Ý¼ÓÃÜ¡£
//	ÊäÈë²ÎÊý£º	pState -- ״̬Êý¾Ý¡£
//	Êä³ö²ÎÊý£º	pState -- ¼ÓÃܺóµÄ״̬Êý¾Ý¡£
//	·µ»ØÖµ£º	ÎÞ¡£
///////////////////////////////////////////////////////////////////////////////
static void BlockEncrypt(unsigned char *pState, unsigned char* pRoundKeyTable)
{
	unsigned char i;
	
	AddRoundKey(pState, pRoundKeyTable);
	
	for (i = 1; i <= Nr; i++) {	// i = [1, Nr]
		SubBytes(pState, 4 * Nb, 0);
		ShiftRows(pState, 0);

		if (i != Nr) MixColumns(pState, 0);

		AddRoundKey(pState, &pRoundKeyTable[4 * Nb * i]);
	}
}

///////////////////////////////////////////////////////////////////////////////
//	º¯ÊýÃû£º	BlockDecrypt
//	ÃèÊö£º		¶Ôµ¥¿éÊý¾Ý½âÃÜ¡£
//	ÊäÈë²ÎÊý£º	pState -- ״̬Êý¾Ý¡£
//	Êä³ö²ÎÊý£º	pState -- ½âÃܺóµÄ״̬Êý¾Ý¡£
//	·µ»ØÖµ£º	ÎÞ¡£
///////////////////////////////////////////////////////////////////////////////
static void BlockDecrypt(unsigned char *pState, unsigned char* pRoundKeyTable)
{
	unsigned char i;
	
	AddRoundKey(pState, &pRoundKeyTable[4*Nb*Nr]);
	
	for (i = Nr; i > 0; i--) {	// i = [Nr, 1]
		ShiftRows(pState, 1);
		SubBytes(pState, 4 * Nb, 1);
		AddRoundKey(pState, &pRoundKeyTable[4 * Nb * (i - 1)]);

		if (i != 1) MixColumns(pState, 1);
	}
}


// À©Õ¹ÃÜÔ¿²Ù
//	ÊäÈë²ÎÊý£ºpKey -- ԭʼÃÜÔ¿£¬Æ䳤¶È±ØÐëΪ AES_KEY_LENGTH/8 ×Ö½Ú¡£
//	Êä³ö²ÎÊý£ºpRoundkeyTable -- À©Õ¹ÃÜÔ¿±í
///////////////////////////////////////////////////////////////////////////////
static void RoundKey(const void *pKey, unsigned char* pRoundkeyTable)
{
	// À©Õ¹ÃÜÔ¿
	unsigned char i;
	unsigned char *pRoundKey;
	unsigned char Rcon[4] = { 0x01, 0x00, 0x00, 0x00 };

	memcpy(pRoundkeyTable, pKey, 4 * Nk);

	pRoundKey = &pRoundkeyTable[4 * Nk];

	for (i = Nk; i < Nb * (Nr +1 ); pRoundKey += 4, i++) {
		memcpy(pRoundKey, pRoundKey - 4, 4);

		if (i % Nk == 0) {
			RotationWord(pRoundKey);
			SubBytes(pRoundKey, 4, 0);
			XorBytes(pRoundKey, Rcon, 4);

			Rcon[0] = GfMultBy02(Rcon[0]);
		} else if (Nk > 6 && i % Nk == Nb) SubBytes(pRoundKey, 4, 0);

		XorBytes(pRoundKey, pRoundKey - 4 * Nk, 4);
	}
}

//////////////////////////////////////////////////////////////////////////
//	º¯ÊýÃû£º	AES_Encrypt
//	ÃèÊö£º		¼ÓÃÜÊý¾Ý
//	ÊäÈë²ÎÊý£º	pKey -- ÃÜÔ¿£¬³¤¶È±ØÐëµÈÓÚÃÜÔ¿³¤¶È
//              pData	-- Ã÷ÎÄ£¬¼´Ðè¼ÓÃܵÄÊý¾Ý£¬Æ䳤¶ÈΪnDataLen×Ö½Ú
//				nDataLen -- Êý¾Ý³¤¶È£¬±ØÐëΪÃÜÔ¿³¤¶ÈµÄÕû±¶Êý
//	Êä³ö²ÎÊý£º	pData	-- ÃÜÎÄ£¬¼´ÓÉÃ÷ÎļÓÃܺóµÄÊý¾Ý£¬µÈÓÚÃ÷Îij¤¶È
//	·µ»ØÖµ£º	ÎÞ¡£
//////////////////////////////////////////////////////////////////////////
void AES_Encrypt(const void *pKey, unsigned char *pData, int nDataLen)
{
	const unsigned char *pIV = IV;
	int i;

	// AES×ÓÃÜÔ¿±í£¬µ±ÃÜÔ¿³¤¶ÈΪ128λʱ£¬Õ¼ÓÃ176×Ö½Ú¿Õ¼ä
	unsigned char roundKeyTable[4*Nb*(Nr+1)];
	RoundKey(pKey, roundKeyTable);

	for(i = nDataLen / (4 * Nb); i > 0 ; i--, pData += 4 * Nb) {
		#if AES_MODE == AES_MODE_CBC
			XorBytes(pData, pIV, 4 * Nb);
		#endif

		BlockEncrypt(pData, roundKeyTable);
		pIV = pData;
	}
}

//////////////////////////////////////////////////////////////////////////
//	º¯ÊýÃû£º	AES_Decrypt
//	ÃèÊö£º		½âÃÜÊý¾Ý
//	ÊäÈë²ÎÊý£º	pKey -- ÃÜÔ¿£¬³¤¶È±ØÐëµÈÓÚÃÜÔ¿³¤¶È
//              pData -- ÃÜÎÄ£¬¼´Ðè½âÃܵÄÊý¾Ý£¬Æ䳤¶ÈΪnDataLen×Ö½Ú
//				nDataLen	-- Êý¾Ý³¤¶È£¬ÒÔ×Ö½ÚΪµ¥Î»£¬±ØÐëΪÃÜÔ¿³¤¶ÈµÄÕû±¶Êý
//	Êä³ö²ÎÊý£º	pData  -- Ã÷ÎÄ£¬¼´ÓÉÃÜÎĽâÃܺóµÄÊý¾Ý£¬µÈÓÚÃÜÎij¤¶È
//	·µ»ØÖµ£º	ÎÞ¡£
//////////////////////////////////////////////////////////////////////////
void AES_Decrypt(const void *pKey, unsigned char *pData, int nDataLen)
{
	int i;

	// AES×ÓÃÜÔ¿±í£¬µ±ÃÜÔ¿³¤¶ÈΪ128λʱ£¬Õ¼ÓÃ176×Ö½Ú¿Õ¼ä
	unsigned char roundKeyTable[4 * Nb * (Nr + 1)];
	RoundKey(pKey, roundKeyTable);

	// ´Ó×îºóÒ»¿éÊý¾Ý¿ªÊ¼½âÃÜ£¬ÕâÑù²»Óÿª±Ù¿Õ¼äÀ´±£´æIV
	pData += nDataLen - 4 * Nb;
	for(i = nDataLen / (4 * Nb); i > 0 ; i--, pData -= 4 * Nb) {
		BlockDecrypt(pData, roundKeyTable);

		#if AES_MODE == AES_MODE_CBC
			if (i == 1) {// ×îºóÒ»¿éÊý¾Ý
				XorBytes(pData, IV, 4 * Nb);
			} else XorBytes(pData, pData - 4 * Nb, 4 * Nb);
		#endif
	}
}


/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// º¯ÊýÃû£º SDK_Encrypt
// ÃèÊö£º   SDK¼ÓÃÜ£¬ÓÉÃ÷Îĵõ½ÃÜÎÄ
// ÊäÈë²ÎÊý£º pData -- Ëæ»úÉú³ÉµÄÃ÷ÎÄ
// Êä³ö²ÎÊý£º pData -- ¼ÓÃܺóµÃµ½µÄÃÜÎÄ
// ·µ»ØÖµ£º   ÎÞ
// ±¸×¢£º   SDKËæ»úÉú³ÉÃ÷ÎÄ£¬½«Ã÷ÎÄ·¢Ë͸øµ÷Ó÷½£¬µ÷Ó÷½½«Ã÷Îıä³ÉÃÜÎÄ´«»ØSDK£¬
//          SDKµ÷Óñ¾½Ó¿ÚÒ²Éú³ÉÃÜÎÄ£¬±È½ÏSDKÉú³ÉµÄÃÜÎÄÓëµ÷Ó÷½´«»ØµÄÃÜÎÄÊÇ·ñÒ»Ö£¬Ò»ÖÂÔòÈÏ֤ͨ¹ý£¬·ñÔòÈÏÖ¤²»Í¨¹ý
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
void TH_SDK_Encrypt(unsigned char* pData)
{
	static unsigned char KEY_CRYPTED[16] = { 0x21, 0x38, 0x42, 0xA9, 0x92, 0x69, 0x5D, 0x8D, 0x8A, 0xD8, 0x4C, 0x4C, 0xE5, 0x3F, 0xED, 0x20 }; // ÃÜÔ¿µÄ¼ÓÃÜÐÎʽ
	static unsigned char KEY_PASSWORD[16] = { 0xE7, 0x44, 0xF2, 0x49, 0x10, 0x80, 0x53, 0x21, 0xD2, 0xA2, 0xFD, 0x36, 0x9D, 0x63, 0x93, 0x2B }; // ½âÃÜÃÜÔ¿µÄÃÜÂë
	static unsigned char KEY[16]; // ʵ¼ÊµÄÃÜÔ¿£¨²»ÒÔÃ÷ÎÄÐÎʽ´æÔÚ´úÂëÖУ©

	// »¹Ô­Êµ¼ÊÃÜÔ¿
	static int bInit = 0;
	if(bInit == 0) {
		bInit = 1;
		memcpy(KEY, KEY_CRYPTED, 16);
		AES_Decrypt(KEY_PASSWORD, KEY, 16);
	}

	// AES¼ÓÃÜ
	AES_Encrypt(KEY, pData, 16);
}