md5.c

来自「Ralink RT61 SoftAP Driver source code. 」· C语言 代码 · 共 1,418 行 · 第 1/4 页

/*
 ***************************************************************************
 * Ralink Tech Inc.
 * 4F, No. 2 Technology	5th	Rd.
 * Science-based Industrial	Park
 * Hsin-chu, Taiwan, R.O.C.
 *
 * (c) Copyright 2002-2006, Ralink Technology, Inc.
 *
 * All rights reserved.	Ralink's source	code is	an unpublished work	and	the
 * use of a	copyright notice does not imply	otherwise. This	source code
 * contains	confidential trade secret material of Ralink Tech. Any attemp
 * or participation	in deciphering,	decoding, reverse engineering or in	any
 * way altering	the	source code	is stricitly prohibited, unless	the	prior
 * written consent of Ralink Technology, Inc. is obtained.
 ***************************************************************************
	
    Module Name:
    md5.c

	Abstract:

	Revision History:
	Who			When			What
	--------	----------		----------------------------------------------
	Name		Date			Modification logs
	jan			10-28-03		Initial
	Rita    	11-23-04		Modify MD5 and SHA-1
	Rita		10-14-05		Modify SHA-1 in big-endian platform
 */
#include "rt_config.h"

/**
 * md5_mac:
 * @key: pointer to	the	key	used for MAC generation
 * @key_len: length	of the key in bytes
 * @data: pointer to the data area for which the MAC is	generated
 * @data_len: length of	the	data in	bytes
 * @mac: pointer to	the	buffer holding space for the MAC; the buffer should
 * have	space for 128-bit (16 bytes) MD5 hash value
 *
 * md5_mac() determines	the	message	authentication code	by using secure	hash
 * MD5(key | data |	key).
 */
void md5_mac(u8 *key, size_t key_len, u8 *data, size_t data_len, u8 *mac)
{
	MD5_CTX	context;

	MD5Init(&context);
	MD5Update(&context,	key, key_len);
	MD5Update(&context,	data, data_len);
	MD5Update(&context,	key, key_len);
	MD5Final(mac, &context);
}

/**
 * hmac_md5:
 * @key: pointer to	the	key	used for MAC generation
 * @key_len: length	of the key in bytes
 * @data: pointer to the data area for which the MAC is	generated
 * @data_len: length of	the	data in	bytes
 * @mac: pointer to	the	buffer holding space for the MAC; the buffer should
 * have	space for 128-bit (16 bytes) MD5 hash value
 *
 * hmac_md5() determines the message authentication	code using HMAC-MD5.
 * This	implementation is based	on the sample code presented in	RFC	2104.
 */
void hmac_md5(u8 *key, size_t key_len, u8 *data, size_t data_len, u8 *mac)
{
	MD5_CTX	context;
    u8 k_ipad[65]; /* inner padding - key XORd with ipad */
    u8 k_opad[65]; /* outer padding - key XORd with opad */
    u8 tk[16];
	int	i;

	//assert(key != NULL && data != NULL && mac != NULL);

	/* if key is longer	than 64	bytes reset	it to key =	MD5(key) */
	if (key_len	> 64) {
		MD5_CTX	ttcontext;

		MD5Init(&ttcontext);
		MD5Update(&ttcontext, key, key_len);
		MD5Final(tk, &ttcontext);
		//key=(PUCHAR)ttcontext.buf;
		key	= tk;
		key_len	= 16;
	}

	/* the HMAC_MD5	transform looks	like:
	 *
	 * MD5(K XOR opad, MD5(K XOR ipad, text))
	 *
	 * where K is an n byte	key
	 * ipad	is the byte	0x36 repeated 64 times
	 * opad	is the byte	0x5c repeated 64 times
	 * and text	is the data	being protected	*/

	/* start out by	storing	key	in pads	*/
	NdisZeroMemory(k_ipad, sizeof(k_ipad));
	NdisZeroMemory(k_opad,	sizeof(k_opad));
	//assert(key_len < sizeof(k_ipad));
	NdisMoveMemory(k_ipad, key,	key_len);
	NdisMoveMemory(k_opad, key,	key_len);

	/* XOR key with	ipad and opad values */
	for	(i = 0;	i <	64;	i++) {
		k_ipad[i] ^= 0x36;
		k_opad[i] ^= 0x5c;
	}

	/* perform inner MD5 */
	MD5Init(&context);					 /*	init context for 1st pass */
	MD5Update(&context,	k_ipad,	64);	 /*	start with inner pad */
	MD5Update(&context,	data, data_len); /*	then text of datagram */
	MD5Final(mac, &context);			 /*	finish up 1st pass */

	/* perform outer MD5 */
	MD5Init(&context);					 /*	init context for 2nd pass */
	MD5Update(&context,	k_opad,	64);	 /*	start with outer pad */
	MD5Update(&context,	mac, 16);		 /*	then results of	1st	hash */
	MD5Final(mac, &context);			 /*	finish up 2nd pass */
}

#ifndef BIG_ENDIAN
#define byteReverse(buf, len)   /* Nothing */
#else
void byteReverse(unsigned char *buf, unsigned longs);
void byteReverse(unsigned char *buf, unsigned longs)
{
    do {
        *(ULONG *)buf = SWAP32(*(ULONG *)buf);
        buf += 4;
    } while (--longs);
}
#endif


/* ==========================  MD5 implementation =========================== */ 
// four base functions for MD5 
#define MD5_F1(x, y, z) (((x) & (y)) | ((~x) & (z))) 
#define MD5_F2(x, y, z) (((x) & (z)) | ((y) & (~z))) 
#define MD5_F3(x, y, z) ((x) ^ (y) ^ (z))
#define MD5_F4(x, y, z) ((y) ^ ((x) | (~z)))
#define CYCLIC_LEFT_SHIFT(w, s) (((w) << (s)) | ((w) >> (32-(s))))

#define	MD5Step(f, w, x, y,	z, data, t, s)	\
	( w	+= f(x,	y, z) +	data + t,  w = (CYCLIC_LEFT_SHIFT(w, s)) & 0xffffffff, w +=	x )


/*
 *  Function Description:
 *      Initiate MD5 Context satisfied in RFC 1321
 *
 *  Arguments:
 *      pCtx        Pointer	to MD5 context
 *
 *  Return Value:
 *      None	    
 */
VOID MD5Init(MD5_CTX *pCtx)
{
    pCtx->Buf[0]=0x67452301;
    pCtx->Buf[1]=0xefcdab89;
    pCtx->Buf[2]=0x98badcfe;
    pCtx->Buf[3]=0x10325476;

    pCtx->LenInBitCount[0]=0;
    pCtx->LenInBitCount[1]=0;
}


/*
 *  Function Description:
 *      Update MD5 Context, allow of an arrary of octets as the next portion 
 *      of the message
 *      
 *  Arguments:
 *      pCtx		Pointer	to MD5 context
 * 	    pData       Pointer to input data
 *      LenInBytes  The length of input data (unit: byte)
 *
 *  Return Value:
 *      None
 *
 *  Note:
 *      Called after MD5Init or MD5Update(itself)   
 */
VOID MD5Update(MD5_CTX *pCtx, UCHAR *pData, ULONG LenInBytes)
{
    
    ULONG TfTimes;
    ULONG temp;
	unsigned int i;
    
    temp = pCtx->LenInBitCount[0];

    pCtx->LenInBitCount[0] = (ULONG) (pCtx->LenInBitCount[0] + (LenInBytes << 3));
 
    if (pCtx->LenInBitCount[0] < temp)
        pCtx->LenInBitCount[1]++;   //carry in

    pCtx->LenInBitCount[1] += LenInBytes >> 29;

    // mod 64 bytes
    temp = (temp >> 3) & 0x3f;  
    
    // process lacks of 64-byte data 
    if (temp) 
    {
        UCHAR *pAds = (UCHAR *) pCtx->Input + temp;
        
        if ((temp+LenInBytes) < 64)
        {
            NdisMoveMemory(pAds, (UCHAR *)pData, LenInBytes);   
            return;
        }
        
        NdisMoveMemory(pAds, (UCHAR *)pData, 64-temp);               
        byteReverse(pCtx->Input, 16);
        MD5Transform(pCtx->Buf, (ULONG *)pCtx->Input);

        pData += 64-temp;
        LenInBytes -= 64-temp; 
    } // end of if (temp)
    
     
    TfTimes = (LenInBytes >> 6);

    for (i=TfTimes; i>0; i--)
    {
        NdisMoveMemory(pCtx->Input, (UCHAR *)pData, 64);
        byteReverse(pCtx->Input, 16);
        MD5Transform(pCtx->Buf, (ULONG *)pCtx->Input);
        pData += 64;
        LenInBytes -= 64;
    } // end of for

    // buffering lacks of 64-byte data
    if(LenInBytes)
        NdisMoveMemory(pCtx->Input, (UCHAR *)pData, LenInBytes);   
   
}


/*
 *  Function Description:
 *      Append padding bits and length of original message in the tail 
 *      The message digest has to be completed in the end  
 *  
 *  Arguments:
 *      Digest		Output of Digest-Message for MD5
 *  	pCtx        Pointer	to MD5 context
 * 	
 *  Return Value:
 *      None
 *  
 *  Note:
 *      Called after MD5Update  
 */
VOID MD5Final(UCHAR Digest[16], MD5_CTX *pCtx)
{
    UCHAR Remainder;
    UCHAR PadLenInBytes;
    UCHAR *pAppend=0;
    unsigned int i;
    
    Remainder = (UCHAR)((pCtx->LenInBitCount[0] >> 3) & 0x3f);

    PadLenInBytes = (Remainder < 56) ? (56-Remainder) : (120-Remainder);
    
    pAppend = (UCHAR *)pCtx->Input + Remainder;

    // padding bits without crossing block(64-byte based) boundary
    if (Remainder < 56)
    {
        *pAppend = 0x80;
        PadLenInBytes --;
        
        NdisZeroMemory((UCHAR *)pCtx->Input + Remainder+1, PadLenInBytes); 
		
		// add data-length field, from low to high
       	for (i=0; i<4; i++)
        {
        	pCtx->Input[56+i] = (UCHAR)((pCtx->LenInBitCount[0] >> (i << 3)) & 0xff);
        	pCtx->Input[60+i] = (UCHAR)((pCtx->LenInBitCount[1] >> (i << 3)) & 0xff);
      	}
      	
        byteReverse(pCtx->Input, 16);
        MD5Transform(pCtx->Buf, (ULONG *)pCtx->Input);
    } // end of if
    
    // padding bits with crossing block(64-byte based) boundary
    else
    {
        // the first block ===
        *pAppend = 0x80;
        PadLenInBytes --;
       
        NdisZeroMemory((UCHAR *)pCtx->Input + Remainder+1, (64-Remainder-1)); 
        PadLenInBytes -= (64 - Remainder - 1);
        
        byteReverse(pCtx->Input, 16);
        MD5Transform(pCtx->Buf, (ULONG *)pCtx->Input);
        

        // the second block ===
        NdisZeroMemory((UCHAR *)pCtx->Input, PadLenInBytes); 

        // add data-length field
        for (i=0; i<4; i++)
        {
        	pCtx->Input[56+i] = (UCHAR)((pCtx->LenInBitCount[0] >> (i << 3)) & 0xff);
        	pCtx->Input[60+i] = (UCHAR)((pCtx->LenInBitCount[1] >> (i << 3)) & 0xff);
      	}

        byteReverse(pCtx->Input, 16);
        MD5Transform(pCtx->Buf, (ULONG *)pCtx->Input);
    } // end of else


    NdisMoveMemory((UCHAR *)Digest, (ULONG *)pCtx->Buf, 16); // output
    byteReverse((UCHAR *)Digest, 4);
    NdisZeroMemory(pCtx, sizeof(pCtx)); // memory free 
}


/*
 *  Function Description:
 *      The central algorithm of MD5, consists of four rounds and sixteen 
 *  	steps per round
 * 
 *  Arguments:
 *      Buf     Buffers of four states (output: 16 bytes)		
 * 	    Mes     Input data (input: 64 bytes) 
 *  
 *  Return Value:
 *      None
 *  	
 *  Note:
 *      Called by MD5Update or MD5Final
 */
VOID MD5Transform(ULONG Buf[4], ULONG Mes[16])
{  
    ULONG Reg[4], Temp; 
	unsigned int i;
    
    static UCHAR LShiftVal[16] = 
    { 	
        7, 12, 17, 22, 	
		5, 9 , 14, 20, 
		4, 11, 16, 23, 
 		6, 10, 15, 21, 
 	};