/* @(#)sha_func.c	1.5 06/09/13 Copyright 1998,1999 Heiko Eissfeldt */
#ifndef lint
static char	sccsid[] =
"@(#)sha_func.c	1.5 06/09/13 Copyright 1998,1999 Heiko Eissfeldt";

#endif
/* NIST Secure Hash Algorithm */

/* heavily modified by Uwe Hollerbach <uh@alumni.caltech edu> */
/* from Peter C. Gutmann's implementation as found in */
/* Applied Cryptography by Bruce Schneier */
/* Further modifications to include the "UNRAVEL" stuff, below */
/* portability modifications Heiko Eissfeldt */

/* This code is in the public domain */

#include "config.h"
#include <schily/string.h>
#include "sha.h"

/* UNRAVEL should be fastest & biggest */
/* UNROLL_LOOPS should be just as big, but slightly slower */
/* both undefined should be smallest and slowest */

#define	UNRAVEL
/* #define	UNROLL_LOOPS */

/* SHA f()-functions */

#define	f1(x, y, z)	((x & y) | (~x & z))
#define	f2(x, y, z)	(x ^ y ^ z)
#define	f3(x, y, z)	((x & y) | (x & z) | (y & z))
#define	f4(x, y, z)	(x ^ y ^ z)

/* SHA constants */

#define	CONST1		ULONG_C(0x5a827999)
#define	CONST2		ULONG_C(0x6ed9eba1)
#define	CONST3		ULONG_C(0x8f1bbcdc)
#define	CONST4		ULONG_C(0xca62c1d6)

/* truncate to 32 bits -- should be a null op on 32-bit machines */

#define	T32(x)	((x) & ULONG_C(0xffffffff))

/* 32-bit rotate */

#define	R32(x, n)	T32(((x << n) | (x >> (32 - n))))

/* the generic case, for when the overall rotation is not unraveled */

/* CONCAT(f, n(B ,C ,D)) does not with K&R C... */
/* BEGIN CSTYLED */
#define	FG(n)	\
	T = T32(R32(A, 5) + CONCAT(f,n(B,C,D)) + E + *WP++ + CONCAT(CONST,n));	\
	E = D; D = C; C = R32(B, 30); B = A; A = T

/* specific cases, for when the overall rotation is unraveled */

#define	FA(n)	\
	T = T32(R32(A, 5) + CONCAT(f,n(B,C,D)) + E + *WP++ + CONCAT(CONST,n)); B = R32(B, 30)

#define	FB(n)	\
	E = T32(R32(T, 5) + CONCAT(f,n(A,B,C)) + D + *WP++ + CONCAT(CONST,n)); A = R32(A, 30)

#define	FC(n)	\
	D = T32(R32(E, 5) + CONCAT(f,n(T,A,B)) + C + *WP++ + CONCAT(CONST,n)); T = R32(T, 30)

#define	FD(n)	\
	C = T32(R32(D, 5) + CONCAT(f,n(E,T,A)) + B + *WP++ + CONCAT(CONST,n)); E = R32(E, 30)

#define	FE(n)	\
	B = T32(R32(C, 5) + CONCAT(f,n(D,E,T)) + A + *WP++ + CONCAT(CONST,n)); D = R32(D, 30)

#define	FT(n)	\
	A = T32(R32(B, 5) + CONCAT(f,n(C,D,E)) + T + *WP++ + CONCAT(CONST,n)); C = R32(C, 30)
/* END CSTYLED */

/* do SHA transformation */

static void sha_transform __PR((SHA_INFO *sha_info));

static void
sha_transform(sha_info)
	SHA_INFO	*sha_info;
{
	int	i;
	BYTE	*dp;
	ULONG	T, A, B, C, D, E, W[80], *WP;

	dp = sha_info->data;

/*
 * the following makes sure that at least one code block below is
 * traversed or an error is reported, without the necessity for nested
 * preprocessor if/else/endif blocks, which are a great pain in the
 * nether regions of the anatomy...
 */
#undef SWAP_DONE

#if (SHA_BYTE_ORDER == 1234)
#define	SWAP_DONE
	for (i = 0; i < 16; ++i) {
		T = *((ULONG *) dp);
		dp += 4;
		W[i] =  ((T << 24) & ULONG_C(0xff000000)) |
			((T <<  8) & ULONG_C(0x00ff0000)) |
			((T >>  8) & ULONG_C(0x0000ff00)) |
			((T >> 24) & ULONG_C(0x000000ff));
	}
#endif /* SHA_BYTE_ORDER == 1234 */

#if (SHA_BYTE_ORDER == 4321)
#define	SWAP_DONE
	for (i = 0; i < 16; ++i) {
		T = *((ULONG *) dp);
		dp += 4;
		W[i] = T32(T);
	}
#endif /* SHA_BYTE_ORDER == 4321 */

#if (SHA_BYTE_ORDER == 12345678)
#define	SWAP_DONE
	for (i = 0; i < 16; i += 2) {
		T = *((ULONG *) dp);
		dp += 8;
		W[i] =  ((T << 24) & ULONG_C(0xff000000)) |
			((T <<  8) & ULONG_C(0x00ff0000)) |
			((T >>  8) & ULONG_C(0x0000ff00)) |
			((T >> 24) & ULONG_C(0x000000ff));
		T >>= 32;
		W[i+1] = ((T << 24) & ULONG_C(0xff000000)) |
			((T <<  8) & ULONG_C(0x00ff0000)) |
			((T >>  8) & ULONG_C(0x0000ff00)) |
			((T >> 24) & ULONG_C(0x000000ff));
	}
#endif /* SHA_BYTE_ORDER == 12345678 */

#if (SHA_BYTE_ORDER == 87654321)
#define	SWAP_DONE
	for (i = 0; i < 16; i += 2) {
		T = *((ULONG *) dp);
		dp += 8;
		W[i] = T32(T >> 32);
		W[i+1] = T32(T);
	}
#endif /* SHA_BYTE_ORDER == 87654321 */

#ifndef SWAP_DONE
error Unknown byte order -- you need to add code here
#endif /* SWAP_DONE */

	for (i = 16; i < 80; ++i) {
		W[i] = W[i-3] ^ W[i-8] ^ W[i-14] ^ W[i-16];
#if (SHA_VERSION == 1)
		W[i] = R32(W[i], 1);
#endif /* SHA_VERSION */
	}
	A = sha_info->digest[0];
	B = sha_info->digest[1];
	C = sha_info->digest[2];
	D = sha_info->digest[3];
	E = sha_info->digest[4];
	WP = W;
#ifdef UNRAVEL
	FA(1); FB(1); FC(1); FD(1); FE(1); FT(1); FA(1); FB(1); FC(1); FD(1);
	FE(1); FT(1); FA(1); FB(1); FC(1); FD(1); FE(1); FT(1); FA(1); FB(1);
	FC(2); FD(2); FE(2); FT(2); FA(2); FB(2); FC(2); FD(2); FE(2); FT(2);
	FA(2); FB(2); FC(2); FD(2); FE(2); FT(2); FA(2); FB(2); FC(2); FD(2);
	FE(3); FT(3); FA(3); FB(3); FC(3); FD(3); FE(3); FT(3); FA(3); FB(3);
	FC(3); FD(3); FE(3); FT(3); FA(3); FB(3); FC(3); FD(3); FE(3); FT(3);
	FA(4); FB(4); FC(4); FD(4); FE(4); FT(4); FA(4); FB(4); FC(4); FD(4);
	FE(4); FT(4); FA(4); FB(4); FC(4); FD(4); FE(4); FT(4); FA(4); FB(4);
	sha_info->digest[0] = T32(sha_info->digest[0] + E);
	sha_info->digest[1] = T32(sha_info->digest[1] + T);
	sha_info->digest[2] = T32(sha_info->digest[2] + A);
	sha_info->digest[3] = T32(sha_info->digest[3] + B);
	sha_info->digest[4] = T32(sha_info->digest[4] + C);
#else /* !UNRAVEL */
#ifdef UNROLL_LOOPS
	FG(1); FG(1); FG(1); FG(1); FG(1); FG(1); FG(1); FG(1); FG(1); FG(1);
	FG(1); FG(1); FG(1); FG(1); FG(1); FG(1); FG(1); FG(1); FG(1); FG(1);
	FG(2); FG(2); FG(2); FG(2); FG(2); FG(2); FG(2); FG(2); FG(2); FG(2);
	FG(2); FG(2); FG(2); FG(2); FG(2); FG(2); FG(2); FG(2); FG(2); FG(2);
	FG(3); FG(3); FG(3); FG(3); FG(3); FG(3); FG(3); FG(3); FG(3); FG(3);
	FG(3); FG(3); FG(3); FG(3); FG(3); FG(3); FG(3); FG(3); FG(3); FG(3);
	FG(4); FG(4); FG(4); FG(4); FG(4); FG(4); FG(4); FG(4); FG(4); FG(4);
	FG(4); FG(4); FG(4); FG(4); FG(4); FG(4); FG(4); FG(4); FG(4); FG(4);
#else /* !UNROLL_LOOPS */
	for (i =  0; i < 20; ++i) { FG(1); }
	for (i = 20; i < 40; ++i) { FG(2); }
	for (i = 40; i < 60; ++i) { FG(3); }
	for (i = 60; i < 80; ++i) { FG(4); }
#endif /* !UNROLL_LOOPS */
	sha_info->digest[0] = T32(sha_info->digest[0] + A);
	sha_info->digest[1] = T32(sha_info->digest[1] + B);
	sha_info->digest[2] = T32(sha_info->digest[2] + C);
	sha_info->digest[3] = T32(sha_info->digest[3] + D);
	sha_info->digest[4] = T32(sha_info->digest[4] + E);
#endif /* !UNRAVEL */
}

/* initialize the SHA digest */

void sha_init __PR((SHA_INFO *sha_info));

void
sha_init(sha_info)
	SHA_INFO	*sha_info;
{
	sha_info->digest[0] = ULONG_C(0x67452301);
	sha_info->digest[1] = ULONG_C(0xefcdab89);
	sha_info->digest[2] = ULONG_C(0x98badcfe);
	sha_info->digest[3] = ULONG_C(0x10325476);
	sha_info->digest[4] = ULONG_C(0xc3d2e1f0);
	sha_info->count_lo = 0L;
	sha_info->count_hi = 0L;
	sha_info->local = 0;
}

/* update the SHA digest */

void sha_update __PR((SHA_INFO *sha_info, BYTE *buffer, int count));

void
sha_update(sha_info, buffer, count)
	SHA_INFO	*sha_info;
	BYTE		*buffer;
	int		count;
{
	int	i;
	ULONG	clo;

	clo = T32(sha_info->count_lo + ((ULONG) count << 3));
	if (clo < sha_info->count_lo) {
		++sha_info->count_hi;
	}
	sha_info->count_lo = clo;
	sha_info->count_hi += (ULONG) count >> 29;
	if (sha_info->local) {
		i = SHA_BLOCKSIZE - sha_info->local;
		if (i > count) {
			i = count;
		}
		memcpy(((BYTE *) sha_info->data) + sha_info->local, buffer, i);
		count -= i;
		buffer += i;
		sha_info->local += i;
		if (sha_info->local == SHA_BLOCKSIZE) {
			sha_transform(sha_info);
		} else {
			return;
		}
	}
	while (count >= SHA_BLOCKSIZE) {
		memcpy(sha_info->data, buffer, SHA_BLOCKSIZE);
		buffer += SHA_BLOCKSIZE;
		count -= SHA_BLOCKSIZE;
		sha_transform(sha_info);
	}
	memcpy(sha_info->data, buffer, count);
	sha_info->local = count;
}

/* finish computing the SHA digest */

void sha_final __PR((unsigned char digest[20], SHA_INFO *sha_info));

void
sha_final(digest, sha_info)
	unsigned char	digest[20];
	SHA_INFO	*sha_info;
{
	int	count;
	ULONG	lo_bit_count, hi_bit_count;

	lo_bit_count = sha_info->count_lo;
	hi_bit_count = sha_info->count_hi;
	count = (int) ((lo_bit_count >> 3) & 0x3f);
	((BYTE *) sha_info->data)[count++] = 0x80;
	if (count > SHA_BLOCKSIZE - 8) {
		memset(((BYTE *) sha_info->data) + count, 0,
						SHA_BLOCKSIZE - count);
		sha_transform(sha_info);
		memset((BYTE *) sha_info->data, 0, SHA_BLOCKSIZE - 8);
	} else {
		memset(((BYTE *) sha_info->data) + count, 0,
			SHA_BLOCKSIZE - 8 - count);
	}
	sha_info->data[56] = (unsigned char) ((hi_bit_count >> 24) & 0xff);
	sha_info->data[57] = (unsigned char) ((hi_bit_count >> 16) & 0xff);
	sha_info->data[58] = (unsigned char) ((hi_bit_count >>  8) & 0xff);
	sha_info->data[59] = (unsigned char) ((hi_bit_count >>  0) & 0xff);
	sha_info->data[60] = (unsigned char) ((lo_bit_count >> 24) & 0xff);
	sha_info->data[61] = (unsigned char) ((lo_bit_count >> 16) & 0xff);
	sha_info->data[62] = (unsigned char) ((lo_bit_count >>  8) & 0xff);
	sha_info->data[63] = (unsigned char) ((lo_bit_count >>  0) & 0xff);
	sha_transform(sha_info);
	digest[ 0] = (unsigned char) ((sha_info->digest[0] >> 24) & 0xff);
	digest[ 1] = (unsigned char) ((sha_info->digest[0] >> 16) & 0xff);
	digest[ 2] = (unsigned char) ((sha_info->digest[0] >>  8) & 0xff);
	digest[ 3] = (unsigned char) ((sha_info->digest[0])	  & 0xff);
	digest[ 4] = (unsigned char) ((sha_info->digest[1] >> 24) & 0xff);
	digest[ 5] = (unsigned char) ((sha_info->digest[1] >> 16) & 0xff);
	digest[ 6] = (unsigned char) ((sha_info->digest[1] >>  8) & 0xff);
	digest[ 7] = (unsigned char) ((sha_info->digest[1])	  & 0xff);
	digest[ 8] = (unsigned char) ((sha_info->digest[2] >> 24) & 0xff);
	digest[ 9] = (unsigned char) ((sha_info->digest[2] >> 16) & 0xff);
	digest[10] = (unsigned char) ((sha_info->digest[2] >>  8) & 0xff);
	digest[11] = (unsigned char) ((sha_info->digest[2])	  & 0xff);
	digest[12] = (unsigned char) ((sha_info->digest[3] >> 24) & 0xff);
	digest[13] = (unsigned char) ((sha_info->digest[3] >> 16) & 0xff);
	digest[14] = (unsigned char) ((sha_info->digest[3] >>  8) & 0xff);
	digest[15] = (unsigned char) ((sha_info->digest[3])	  & 0xff);
	digest[16] = (unsigned char) ((sha_info->digest[4] >> 24) & 0xff);
	digest[17] = (unsigned char) ((sha_info->digest[4] >> 16) & 0xff);
	digest[18] = (unsigned char) ((sha_info->digest[4] >>  8) & 0xff);
	digest[19] = (unsigned char) ((sha_info->digest[4])	  & 0xff);
}

#ifdef SHA_FOR_C

/* compute the SHA digest of a FILE stream */

#define	BLOCK_SIZE	8192

void sha_stream __PR((unsigned char digest[20], SHA_INFO *sha_info, FILE *fin));

void
sha_stream(digest, sha_info, fin)
	unsigned char	digest[20];
	SHA_INFO	*sha_info;
	FILE		*fin;
{
	int	i;
	BYTE	data[BLOCK_SIZE];

	sha_init(sha_info);
	while ((i = fread(data, 1, BLOCK_SIZE, fin)) > 0) {
		sha_update(sha_info, data, i);
	}
	sha_final(digest, sha_info);
}

/* print a SHA digest */

void sha_print __PR((unsigned char digest[20]));

void
sha_print(digest)
	unsigned char	digest[20];
{
	int	i, j;

	for (j = 0; j < 5; ++j) {
		for (i = 0; i < 4; ++i) {
			printf("%02x", *digest++);
		}
		printf("%c", (j < 4) ? ' ' : '\n');
	}
}

char *sha_version __PR((void));

char *
sha_version()
{
#if (SHA_VERSION == 1)
static char	*version = "SHA-1";
#else
static char	*version = "SHA";
#endif
	return (version);
}

#endif /* SHA_FOR_C */
