/*$KAME: sha1.c,v 1.5 2000/11/08 06:13:08 itojun Exp $	*/
/*
 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the project nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */
/*
 * Portions copyright (c) 2010, Intel Corporation
 */

/*
 * From:  FreeBSD sys/crypto/sha1.c
 */

/*
 * FIPS pub 180-1: Secure Hash Algorithm (SHA-1)
 * based on: http://csrc.nist.gov/fips/fip180-1.txt
 * implemented by Jun-ichiro itojun Itoh <itojun@itojun.org>
 */

#include <types.h>
#include <compiler.h>
#include <string.h>
#include <sha1.h>

#define BIG_ENDIAN \
    (!(__x86_64__ || __i386__ || _M_IX86 || _M_X64 || __ARMEL__ || __MIPSEL__))
#define LITTLE_ENDIAN   !BIG_ENDIAN

/* constant table */
static uint32_t _K[] = { 0x5a827999, 0x6ed9eba1, 0x8f1bbcdc, 0xca62c1d6 };
#define	K(t)	_K[(t) / 20]
#define	F0(b, c, d)	(((b) & (c)) | ((~(b)) & (d)))
#define	F1(b, c, d)	(((b) ^ (c)) ^ (d))
#define	F2(b, c, d)	(((b) & (c)) | ((b) & (d)) | ((c) & (d)))
#define	F3(b, c, d)	(((b) ^ (c)) ^ (d))
#define	S(n, x) 	(((x) << (n)) | ((x) >> (32 - n)))
#define	H(n)	(ctxt->h.b32[(n)])
#define	COUNT	(ctxt->count)
#define	BCOUNT	(ctxt->c.b64[0] / 8)
#define	W(n)	(ctxt->m.b32[(n)])
#define	PUTBYTE(x){\
    ctxt->m.b8[(COUNT % 64)] = (x);\
    COUNT++;\
    COUNT %= 64;\
    ctxt->c.b64[0] += 8;\
    if (COUNT % 64 == 0)\
        sha1_step(ctxt);\
     }
#define PUTPAD(x){\
    ctxt->m.b8[(COUNT % 64)] = (x);\
    COUNT++;\
    COUNT %= 64;\
    if (COUNT % 64 == 0)\
        sha1_step(ctxt);\
     }
static void sha1_step(struct sha1_ctxt *ctxt)
{
    uint32_t    a, b, c, d, e;
    size_t t, s;
    uint32_t    tmp;

#if LITTLE_ENDIAN
    struct sha1_ctxt tctxt;
    tb_memcpy(&tctxt.m.b8[0], &ctxt->m.b8[0], 64);
    ctxt->m.b8[0] = tctxt.m.b8[3]; ctxt->m.b8[1] = tctxt.m.b8[2];
    ctxt->m.b8[2] = tctxt.m.b8[1]; ctxt->m.b8[3] = tctxt.m.b8[0];
    ctxt->m.b8[4] = tctxt.m.b8[7]; ctxt->m.b8[5] = tctxt.m.b8[6];
    ctxt->m.b8[6] = tctxt.m.b8[5]; ctxt->m.b8[7] = tctxt.m.b8[4];
    ctxt->m.b8[8] = tctxt.m.b8[11]; ctxt->m.b8[9] = tctxt.m.b8[10];
    ctxt->m.b8[10] = tctxt.m.b8[9]; ctxt->m.b8[11] = tctxt.m.b8[8];
    ctxt->m.b8[12] = tctxt.m.b8[15]; ctxt->m.b8[13] = tctxt.m.b8[14];
    ctxt->m.b8[14] = tctxt.m.b8[13]; ctxt->m.b8[15] = tctxt.m.b8[12];
    ctxt->m.b8[16] = tctxt.m.b8[19]; ctxt->m.b8[17] = tctxt.m.b8[18];
    ctxt->m.b8[18] = tctxt.m.b8[17]; ctxt->m.b8[19] = tctxt.m.b8[16];
    ctxt->m.b8[20] = tctxt.m.b8[23]; ctxt->m.b8[21] = tctxt.m.b8[22];
    ctxt->m.b8[22] = tctxt.m.b8[21]; ctxt->m.b8[23] = tctxt.m.b8[20];
    ctxt->m.b8[24] = tctxt.m.b8[27]; ctxt->m.b8[25] = tctxt.m.b8[26];
    ctxt->m.b8[26] = tctxt.m.b8[25]; ctxt->m.b8[27] = tctxt.m.b8[24];
    ctxt->m.b8[28] = tctxt.m.b8[31]; ctxt->m.b8[29] = tctxt.m.b8[30];
    ctxt->m.b8[30] = tctxt.m.b8[29]; ctxt->m.b8[31] = tctxt.m.b8[28];
    ctxt->m.b8[32] = tctxt.m.b8[35]; ctxt->m.b8[33] = tctxt.m.b8[34];
    ctxt->m.b8[34] = tctxt.m.b8[33]; ctxt->m.b8[35] = tctxt.m.b8[32];
    ctxt->m.b8[36] = tctxt.m.b8[39]; ctxt->m.b8[37] = tctxt.m.b8[38];
    ctxt->m.b8[38] = tctxt.m.b8[37]; ctxt->m.b8[39] = tctxt.m.b8[36];
    ctxt->m.b8[40] = tctxt.m.b8[43]; ctxt->m.b8[41] = tctxt.m.b8[42];
    ctxt->m.b8[42] = tctxt.m.b8[41]; ctxt->m.b8[43] = tctxt.m.b8[40];
    ctxt->m.b8[44] = tctxt.m.b8[47]; ctxt->m.b8[45] = tctxt.m.b8[46];
    ctxt->m.b8[46] = tctxt.m.b8[45]; ctxt->m.b8[47] = tctxt.m.b8[44];
    ctxt->m.b8[48] = tctxt.m.b8[51]; ctxt->m.b8[49] = tctxt.m.b8[50];
    ctxt->m.b8[50] = tctxt.m.b8[49]; ctxt->m.b8[51] = tctxt.m.b8[48];
    ctxt->m.b8[52] = tctxt.m.b8[55]; ctxt->m.b8[53] = tctxt.m.b8[54];
    ctxt->m.b8[54] = tctxt.m.b8[53]; ctxt->m.b8[55] = tctxt.m.b8[52];
    ctxt->m.b8[56] = tctxt.m.b8[59]; ctxt->m.b8[57] = tctxt.m.b8[58];
    ctxt->m.b8[58] = tctxt.m.b8[57]; ctxt->m.b8[59] = tctxt.m.b8[56];
    ctxt->m.b8[60] = tctxt.m.b8[63]; ctxt->m.b8[61] = tctxt.m.b8[62];
    ctxt->m.b8[62] = tctxt.m.b8[61]; ctxt->m.b8[63] = tctxt.m.b8[60];
#endif

    a = H(0); b = H(1); c = H(2); d = H(3); e = H(4);

    for (t = 0; t < 20; t++) {
        s = t & 0x0f;
        if (t >= 16){
            W(s) = S(1, W((s+13) & 0x0f) ^ W((s+8) & 0x0f) ^ W((s+2) & 0x0f) ^ W(s));
        }
        tmp = S(5, a) + F0(b, c, d) + e + W(s) + K(t);
        e = d; d = c; c = S(30, b); b = a; a = tmp;
    }
    for (t = 20; t < 40; t++) {
        s = t & 0x0f;
        W(s) = S(1, W((s+13) & 0x0f) ^ W((s+8) & 0x0f) ^ W((s+2) & 0x0f) ^ W(s));
        tmp = S(5, a) + F1(b, c, d) + e + W(s) + K(t);
        e = d; d = c; c = S(30, b); b = a; a = tmp;
    }
    for (t = 40; t < 60; t++) {
        s = t & 0x0f;
        W(s) = S(1, W((s+13) & 0x0f) ^ W((s+8) & 0x0f) ^ W((s+2) & 0x0f) ^ W(s));
        tmp = S(5, a) + F2(b, c, d) + e + W(s) + K(t);
        e = d; d = c; c = S(30, b); b = a; a = tmp;
    }
    for (t = 60; t < 80; t++) {
        s = t & 0x0f;
        W(s) = S(1, W((s+13) & 0x0f) ^ W((s+8) & 0x0f) ^ W((s+2) & 0x0f) ^ W(s));
        tmp = S(5, a) + F3(b, c, d) + e + W(s) + K(t);
        e = d; d = c; c = S(30, b); b = a; a = tmp;
    }

    H(0) = H(0) + a;
    H(1) = H(1) + b;
    H(2) = H(2) + c;
    H(3) = H(3) + d;
    H(4) = H(4) + e;

    tb_memset(&ctxt->m.b8[0],0, 64);
}

/*------------------------------------------------------------*/

void sha1_init(struct sha1_ctxt *ctxt)
{
    tb_memset(ctxt,0, sizeof(struct sha1_ctxt));
    H(0) = 0x67452301;
    H(1) = 0xefcdab89;
    H(2) = 0x98badcfe;
    H(3) = 0x10325476;
    H(4) = 0xc3d2e1f0;
}

void sha1_pad(struct sha1_ctxt *ctxt)
{
    size_t padlen;    /*pad length in bytes*/
    size_t padstart;

    PUTPAD(0x80);
    
    padstart = COUNT % 64;
    padlen = 64 - padstart;
    if (padlen < 8) {
        tb_memset(&ctxt->m.b8[padstart],0, padlen);
        COUNT += padlen;
        COUNT %= 64;
        sha1_step(ctxt);
        padstart = COUNT % 64;    /* should be 0 */
        padlen = 64 - padstart;   /* should be 64 */
    }
    tb_memset(&ctxt->m.b8[padstart],0, padlen - 8);
    COUNT += (padlen - 8);
    COUNT %= 64;
#if BIG_ENDIAN
    PUTPAD(ctxt->c.b8[0]); PUTPAD(ctxt->c.b8[1]);
    PUTPAD(ctxt->c.b8[2]); PUTPAD(ctxt->c.b8[3]);
    PUTPAD(ctxt->c.b8[4]); PUTPAD(ctxt->c.b8[5]);
    PUTPAD(ctxt->c.b8[6]); PUTPAD(ctxt->c.b8[7]);
#else
    PUTPAD(ctxt->c.b8[7]); PUTPAD(ctxt->c.b8[6]);
    PUTPAD(ctxt->c.b8[5]); PUTPAD(ctxt->c.b8[4]);
    PUTPAD(ctxt->c.b8[3]); PUTPAD(ctxt->c.b8[2]);
    PUTPAD(ctxt->c.b8[1]); PUTPAD(ctxt->c.b8[0]);
#endif
}

void sha1_loop(struct sha1_ctxt *ctxt,const uint8_t *input,size_t len)
{
    size_t gaplen;
    size_t gapstart;
    size_t off;
    size_t copysiz;

    off = 0;

    while (off < len) {
        gapstart = COUNT % 64;
        gaplen = 64 - gapstart;

        copysiz = (gaplen < len - off) ? gaplen : len - off;
        tb_memcpy(&ctxt->m.b8[gapstart],&input[off], copysiz);
        COUNT += copysiz;
        COUNT %= 64;
        ctxt->c.b64[0] += copysiz * 8;
        if (COUNT % 64 == 0)
            sha1_step(ctxt);
        off += copysiz;
    }
}

void sha1_result(struct sha1_ctxt *ctxt,unsigned char *digest0)
{
    uint8_t *digest;
    digest = (uint8_t *)digest0;
    sha1_pad(ctxt);
#if BIG_ENDIAN
    tb_memcpy(digest, &ctxt->h.b8[0],20);
#else
    digest[0] = ctxt->h.b8[3]; digest[1] = ctxt->h.b8[2];
    digest[2] = ctxt->h.b8[1]; digest[3] = ctxt->h.b8[0];
    digest[4] = ctxt->h.b8[7]; digest[5] = ctxt->h.b8[6];
    digest[6] = ctxt->h.b8[5]; digest[7] = ctxt->h.b8[4];
    digest[8] = ctxt->h.b8[11]; digest[9] = ctxt->h.b8[10];
    digest[10] = ctxt->h.b8[9]; digest[11] = ctxt->h.b8[8];
    digest[12] = ctxt->h.b8[15]; digest[13] = ctxt->h.b8[14];
    digest[14] = ctxt->h.b8[13]; digest[15] = ctxt->h.b8[12];
    digest[16] = ctxt->h.b8[19]; digest[17] = ctxt->h.b8[18];
    digest[18] = ctxt->h.b8[17]; digest[19] = ctxt->h.b8[16];
#endif
}

int sha1_buffer(const unsigned char *buffer, size_t len,
                unsigned char md[SHA_DIGEST_LENGTH])
{
    SHA_CTX c;

    if (md == NULL)
        return 1;
    SHA1_Init(&c);
    SHA1_Update(&c,buffer,len);
    SHA1_Final(md,&c);
    return 0;
}

