/* $OpenBSD: sha1.c,v 1.9 2011/01/11 15:50:40 deraadt Exp $ */

/*

* SHA-1 in C

* By Steve Reid <steve@edmweb.com>

* 100% Public Domain

*

* Test Vectors (from FIPS PUB 180-1)

* "abc"

* A9993E36 4706816A BA3E2571 7850C26C 9CD0D89D

* "abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq"

* 84983E44 1C3BD26E BAAE4AA1 F95129E5 E54670F1

* A million repetitions of "a"

* 34AA973C D4C4DAA4 F61EEB2B DBAD2731 6534016F

*/

/* #define LITTLE_ENDIAN * This should be #define'd already, if true. */

/* #define SHA1HANDSOFF * Copies data before messing with it. */

#define SHA1HANDSOFF

#include <string.h>

#include <sys/param.h>

//#include <sys/systm.h>

#include "sha1.h"

#define rol(value, bits) (((value) << (bits)) | ((value) >> (32 - (bits))))

/* blk0() and blk() perform the initial expand. */

/* I got the idea of expanding during the round function from SSLeay */

#if PLATFORM_LITTLEENDIAN

#define blk0(i) (block->l[i] = (rol(block->l[i],24)&0xFF00FF00) \

|(rol(block->l[i],8)&0x00FF00FF))

#else

#define blk0(i) block->l[i]

#endif

#define blk(i) (block->l[i&15] = rol(block->l[(i+13)&15]^block->l[(i+8)&15] \

^block->l[(i+2)&15]^block->l[i&15],1))

/* (R0+R1), R2, R3, R4 are the different operations used in SHA1 */

#define R0(v,w,x,y,z,i) z+=((w&(x^y))^y)+blk0(i)+0x5A827999+rol(v,5);w=rol(w,30);

#define R1(v,w,x,y,z,i) z+=((w&(x^y))^y)+blk(i)+0x5A827999+rol(v,5);w=rol(w,30);

#define R2(v,w,x,y,z,i) z+=(w^x^y)+blk(i)+0x6ED9EBA1+rol(v,5);w=rol(w,30);

#define R3(v,w,x,y,z,i) z+=(((w|x)&y)|(w&x))+blk(i)+0x8F1BBCDC+rol(v,5);w=rol(w,30);

#define R4(v,w,x,y,z,i) z+=(w^x^y)+blk(i)+0xCA62C1D6+rol(v,5);w=rol(w,30);

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

void

SHA1Transform(uint32_t state[5], const uint8_t buffer[SHA1_BLOCK_LENGTH])

{

uint32_t a, b, c, d, e;

typedef union {

uint8_t c[64];

uint32_t l[16];

} CHAR64LONG16;

CHAR64LONG16* block;

#ifdef SHA1HANDSOFF

uint8_t workspace[SHA1_BLOCK_LENGTH];

block = (CHAR64LONG16 *)workspace;

memcpy(block, buffer, SHA1_BLOCK_LENGTH);

#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->count = 0;

context->state[0] = 0x67452301;

context->state[1] = 0xEFCDAB89;

context->state[2] = 0x98BADCFE;

context->state[3] = 0x10325476;

context->state[4] = 0xC3D2E1F0;

}

/* Run your data through this. */

void

SHA1Update(SHA1_CTX *context, const uint8_t *data, const uint32_t len)

{

uint32_t i;

uint32_t j;

j = (uint32_t)((context->count >> 3) & 63);

context->count += (len << 3);

if ((j + len) > 63) {

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;

memcpy(&context->buffer[j], &data[i], len - i);

}

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

void

SHA1Final(uint8_t digest[SHA1_DIGEST_LENGTH], SHA1_CTX *context)

{

unsigned int i;

uint8_t finalcount[8];

for (i = 0; i < 8; i++) {

finalcount[i] = (uint8_t)((context->count >>

((7 - (i & 7)) * 8)) & 255); /* Endian independent */

}

SHA1Update(context, (uint8_t *)"\200", 1);

while ((context->count & 504) != 448) {

SHA1Update(context, (uint8_t *)"\0", 1);

}

SHA1Update(context, finalcount, 8); /* Should cause a SHA1Transform() */

if (digest)

for (i = 0; i < SHA1_DIGEST_LENGTH; i++) {

digest[i] = (uint8_t)((context->state[i >> 2] >>

((3 - (i & 3)) * 8)) & 255);

}

memset(finalcount, '\0', 8);

#if 0 /* We want to use this for "keyfill" */

/* Wipe variables */

i = 0;

bzero(context->buffer, 64);

bzero(context->state, 20);

bzero(context->count, 8);

#ifdef SHA1HANDSOFF /* make SHA1Transform overwrite its own static vars */

SHA1Transform(context->state, context->buffer);

#endif

#endif

}

/* https://www.ietf.org/rfc/rfc2104.txt */

void SHA1Hmac(const uint8_t *key, const uint32_t keylen, const uint8_t *msg, const uint32_t msglen, uint8_t digest[SHA1_DIGEST_LENGTH])

{

SHA1_CTX sha1;

uint8_t block[64]; // 512 bits.

uint8_t xori[sizeof (block)];

uint8_t xoro[sizeof (block)];

int i;

memset(block, '\0', sizeof (block));

if (keylen <= sizeof (block)) {

memcpy(block, key, keylen);

} else {

/* SHA-1 the key itself to shrink it down. */

SHA1Init(&sha1);

SHA1Update(&sha1, key, keylen);

SHA1Final(block, &sha1);

}

for (i = 0; i < sizeof (block); i++) {

const uint8_t b = block[i];

xori[i] = b ^ 0x36; /* XOR block vs ipad value */

xoro[i] = b ^ 0x5C; /* XOR block vs opad value */

}

SHA1Init(&sha1);

SHA1Update(&sha1, xori, sizeof (xori));

SHA1Update(&sha1, msg, msglen);

SHA1Final(block, &sha1);

SHA1Init(&sha1);

SHA1Update(&sha1, xoro, sizeof (xoro));

SHA1Update(&sha1, block, SHA1_DIGEST_LENGTH);

SHA1Final(digest, &sha1);

}