hmac_sha1.c

软件实现SHA1的HMAC算法

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <memory.h>

#include "hmac_sha1.h"

/* Hash a single 512-bit block. This is the core of the algorithm. */

void SHA1Transform(__u32 state[5], __u8 buffer[64])
{
__u32 a, b, c, d, e;
typedef union {
    unsigned char c[64];
    __u32 l[16];
} CHAR64LONG16;

CHAR64LONG16* block;

#ifdef SHA1HANDSOFF

static unsigned char workspace[64];
    block = (CHAR64LONG16*)workspace;
//    NdisMoveMemory(block, buffer, 64);
    memcpy(block, buffer, 64);
#else
    block = (CHAR64LONG16*)buffer;
#endif
    /* Copy context->state[] to working vars */
    a = state[0];
    b = state[1];
    c = state[2];
    d = state[3];
    e = state[4];
    /* 4 rounds of 20 operations each. Loop unrolled. */
    R0(a,b,c,d,e, 0); R0(e,a,b,c,d, 1); R0(d,e,a,b,c, 2); R0(c,d,e,a,b, 3);
    R0(b,c,d,e,a, 4); R0(a,b,c,d,e, 5); R0(e,a,b,c,d, 6); R0(d,e,a,b,c, 7);
    R0(c,d,e,a,b, 8); R0(b,c,d,e,a, 9); R0(a,b,c,d,e,10); R0(e,a,b,c,d,11);
    R0(d,e,a,b,c,12); R0(c,d,e,a,b,13); R0(b,c,d,e,a,14); R0(a,b,c,d,e,15);
    R1(e,a,b,c,d,16); R1(d,e,a,b,c,17); R1(c,d,e,a,b,18); R1(b,c,d,e,a,19);
    R2(a,b,c,d,e,20); R2(e,a,b,c,d,21); R2(d,e,a,b,c,22); R2(c,d,e,a,b,23);
    R2(b,c,d,e,a,24); R2(a,b,c,d,e,25); R2(e,a,b,c,d,26); R2(d,e,a,b,c,27);
    R2(c,d,e,a,b,28); R2(b,c,d,e,a,29); R2(a,b,c,d,e,30); R2(e,a,b,c,d,31);
    R2(d,e,a,b,c,32); R2(c,d,e,a,b,33); R2(b,c,d,e,a,34); R2(a,b,c,d,e,35);
    R2(e,a,b,c,d,36); R2(d,e,a,b,c,37); R2(c,d,e,a,b,38); R2(b,c,d,e,a,39);
    R3(a,b,c,d,e,40); R3(e,a,b,c,d,41); R3(d,e,a,b,c,42); R3(c,d,e,a,b,43);
    R3(b,c,d,e,a,44); R3(a,b,c,d,e,45); R3(e,a,b,c,d,46); R3(d,e,a,b,c,47);
    R3(c,d,e,a,b,48); R3(b,c,d,e,a,49); R3(a,b,c,d,e,50); R3(e,a,b,c,d,51);
    R3(d,e,a,b,c,52); R3(c,d,e,a,b,53); R3(b,c,d,e,a,54); R3(a,b,c,d,e,55);
    R3(e,a,b,c,d,56); R3(d,e,a,b,c,57); R3(c,d,e,a,b,58); R3(b,c,d,e,a,59);
    R4(a,b,c,d,e,60); R4(e,a,b,c,d,61); R4(d,e,a,b,c,62); R4(c,d,e,a,b,63);
    R4(b,c,d,e,a,64); R4(a,b,c,d,e,65); R4(e,a,b,c,d,66); R4(d,e,a,b,c,67);
    R4(c,d,e,a,b,68); R4(b,c,d,e,a,69); R4(a,b,c,d,e,70); R4(e,a,b,c,d,71);
    R4(d,e,a,b,c,72); R4(c,d,e,a,b,73); R4(b,c,d,e,a,74); R4(a,b,c,d,e,75);
    R4(e,a,b,c,d,76); R4(d,e,a,b,c,77); R4(c,d,e,a,b,78); R4(b,c,d,e,a,79);
    /* Add the working vars back into context.state[] */
    state[0] += a;
    state[1] += b;
    state[2] += c;
    state[3] += d;
    state[4] += e;
    /* Wipe variables */
    a = b = c = d = e = 0;
}


/* SHA1Init - Initialize new context */

void SHA1Init(SHA1_CTX* context)
{
    /* SHA1 initialization constants */
    context->state[0] = 0x67452301;
    context->state[1] = 0xEFCDAB89;
    context->state[2] = 0x98BADCFE;
    context->state[3] = 0x10325476;
    context->state[4] = 0xC3D2E1F0;
    context->count[0] = context->count[1] = 0;
}


/* Run your data through this. */

void SHA1Update(SHA1_CTX* context, unsigned char* data, __u32 len)
{
	__u32 i, j;

    j = context->count[0];
    if ((context->count[0] += len << 3) < j)
	context->count[1]++;
    context->count[1] += (len>>29);
    j = (j >> 3) & 63;
    if ((j + len) > 63) {
//        NdisMoveMemory(&context->buffer[j], data, (i = 64-j));
        memcpy(&context->buffer[j], data, (i = 64-j));
        SHA1Transform(context->state, context->buffer);
        for ( ; i + 63 < len; i += 64) {
            SHA1Transform(context->state, &data[i]);
        }
        j = 0;
    }
    else i = 0;
//    NdisMoveMemory(&context->buffer[j], &data[i], len - i);
    memcpy(&context->buffer[j], &data[i], len - i);
}


/* Add padding and return the message digest. */

void SHA1Final(unsigned char digest[20], SHA1_CTX* context)
{
__u32 i, j;
unsigned char finalcount[8];

    for (i = 0; i < 8; i++) {
        finalcount[i] = (unsigned char)((context->count[(i >= 4 ? 0 : 1)]
         >> ((3-(i & 3)) * 8) ) & 255);  /* Endian independent */
    }
    SHA1Update(context, (unsigned char *)"\200", 1);
    while ((context->count[0] & 504) != 448) {
        SHA1Update(context, (unsigned char *)"\0", 1);
    }
    SHA1Update(context, finalcount, 8);  /* Should cause a SHA1Transform() */
    for (i = 0; i < 20; i++) {
        digest[i] = (unsigned char)
         ((context->state[i>>2] >> ((3-(i & 3)) * 8) ) & 255);
    }
    /* Wipe variables */
    i = j = 0;
//    NdisZeroMemory(context->buffer, 64);
//    NdisZeroMemory(context->state, 20);
//    NdisZeroMemory(context->count, 8);
//    NdisZeroMemory(&finalcount, 8);
    memset(context->buffer, 0x00, 64);
    memset(context->state, 0x00, 20);
    memset(context->count, 0x00, 8);
    memset(&finalcount, 0x00, 8);
    
#ifdef SHA1HANDSOFF  /* make SHA1Transform overwrite its own static vars */
    SHA1Transform(context->state, context->buffer);
#endif
}

void hmac_sha1(unsigned char *to_mac,unsigned int to_mac_length, unsigned char *key,unsigned int key_length, unsigned char *out_mac)
{
	unsigned char digest[20];
	int i;
	SHA1_CTX	sha1_ctx;
	unsigned char k_ipad[65];    /* inner padding -
                                      * key XORd with ipad
                                      */
	unsigned char k_opad[65];    /* outer padding -
                                      * key XORd with opad
                                      */
	       /* start out by storing key in pads */
    //   if (key_length>512)
    //   	return 1;
//	NdisZeroMemory(k_ipad, sizeof k_ipad);
//	NdisZeroMemory(k_opad, sizeof k_opad);
//	NdisMoveMemory(k_ipad, key,key_length);
//	NdisMoveMemory(k_opad, key,key_length);
	memset(k_ipad, 0x00, sizeof(k_ipad));
	memset(k_opad, 0x00, sizeof(k_opad));
	memcpy(k_ipad, key, key_length);
	memcpy(k_opad, key, key_length);


        /* XOR key with ipad and opad values */
	for (i=0; i<64; i++) {
		k_ipad[i] ^= 0x36;
		k_opad[i] ^= 0x5c;
	}
	
	SHA1Init(&sha1_ctx);                   /* init sha1_ctx for 1st
       * pass */

	SHA1Update(&sha1_ctx,to_mac, to_mac_length); /* then text of datagram */
	SHA1Final(digest, &sha1_ctx);          /* finish up 1st pass */
        /*
         * perform outer 
         */
	SHA1Init(&sha1_ctx);                   /* init sha1_ctx for 2nd
                                              * pass */
	SHA1Update(&sha1_ctx, k_opad, 64);     /* start with outer pad */
	SHA1Update(&sha1_ctx, digest, 20);     /* then results of 1st*/
        /* hash */
	SHA1Final(out_mac, &sha1_ctx);          /* finish up 2nd pass */
	//return 0;
}

int DTCSP_Hmac_Sha1(
	void          *pContext,
	unsigned char *pSha1Key,
	int            nSha1KeyLen,
	unsigned char *pInData,
	int            nInDataLen,
	unsigned char *pOutData,
	int           *pOutDataLen)
{
	if(nSha1KeyLen > 64)
		return 0xEE20;
	hmac_sha1(pInData, nInDataLen, pSha1Key, nSha1KeyLen, pOutData);
	*pOutDataLen = 20;
	return 0;
}