/*
 *  FIPS-180-1 compliant SHA-1 implementation
 *
 *  Copyright (C) 2001-2003  Christophe Devine
 *  Copyright (C) 2012       Chris Elston, Katalix Systems Ltd <celston@katalix.com>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 *
 *  Changed to use guint instead of uint 2004 by Anders Broman
 *  Original code found at http://www.cr0.net:8040/code/crypto/sha1/
 *  References: http://www.ietf.org/rfc/rfc3174.txt?number=3174
 *
 *  2012-08-21 - C Elston - Split sha1_hmac function to allow incremental usage.
 */

#include <string.h>
#include <glib.h>

#include "sha1.h"

#define GET_UINT32(n,b,i)                       \
{                                               \
    (n) = ( (guint32) (b)[(i)    ] << 24 )       \
        | ( (guint32) (b)[(i) + 1] << 16 )       \
        | ( (guint32) (b)[(i) + 2] <<  8 )       \
        | ( (guint32) (b)[(i) + 3]       );      \
}

#define PUT_UINT32(n,b,i)                       \
{                                               \
    (b)[(i)    ] = (guint8) ( (n) >> 24 );       \
    (b)[(i) + 1] = (guint8) ( (n) >> 16 );       \
    (b)[(i) + 2] = (guint8) ( (n) >>  8 );       \
    (b)[(i) + 3] = (guint8) ( (n)       );       \
}

void sha1_starts( sha1_context *ctx )
{
    ctx->total[0] = 0;
    ctx->total[1] = 0;

    ctx->state[0] = 0x67452301;
    ctx->state[1] = 0xEFCDAB89;
    ctx->state[2] = 0x98BADCFE;
    ctx->state[3] = 0x10325476;
    ctx->state[4] = 0xC3D2E1F0;
}

static void sha1_process( sha1_context *ctx, const guint8 data[64] )
{
    guint32 temp, W[16], A, B, C, D, E;

    GET_UINT32( W[0],  data,  0 );
    GET_UINT32( W[1],  data,  4 );
    GET_UINT32( W[2],  data,  8 );
    GET_UINT32( W[3],  data, 12 );
    GET_UINT32( W[4],  data, 16 );
    GET_UINT32( W[5],  data, 20 );
    GET_UINT32( W[6],  data, 24 );
    GET_UINT32( W[7],  data, 28 );
    GET_UINT32( W[8],  data, 32 );
    GET_UINT32( W[9],  data, 36 );
    GET_UINT32( W[10], data, 40 );
    GET_UINT32( W[11], data, 44 );
    GET_UINT32( W[12], data, 48 );
    GET_UINT32( W[13], data, 52 );
    GET_UINT32( W[14], data, 56 );
    GET_UINT32( W[15], data, 60 );

#define S(x,n) ((x << n) | ((x & 0xFFFFFFFF) >> (32 - n)))

#define R(t)                                            \
(                                                       \
    temp = W[(t -  3) & 0x0F] ^ W[(t - 8) & 0x0F] ^     \
           W[(t - 14) & 0x0F] ^ W[ t      & 0x0F],      \
    ( W[t & 0x0F] = S(temp,1) )                         \
)

#define P(a,b,c,d,e,x)                                  \
{                                                       \
    e += S(a,5) + F(b,c,d) + K + x; b = S(b,30);        \
}

    A = ctx->state[0];
    B = ctx->state[1];
    C = ctx->state[2];
    D = ctx->state[3];
    E = ctx->state[4];

#define F(x,y,z) (z ^ (x & (y ^ z)))
#define K 0x5A827999

    P( A, B, C, D, E, W[0]  );
    P( E, A, B, C, D, W[1]  );
    P( D, E, A, B, C, W[2]  );
    P( C, D, E, A, B, W[3]  );
    P( B, C, D, E, A, W[4]  );
    P( A, B, C, D, E, W[5]  );
    P( E, A, B, C, D, W[6]  );
    P( D, E, A, B, C, W[7]  );
    P( C, D, E, A, B, W[8]  );
    P( B, C, D, E, A, W[9]  );
    P( A, B, C, D, E, W[10] );
    P( E, A, B, C, D, W[11] );
    P( D, E, A, B, C, W[12] );
    P( C, D, E, A, B, W[13] );
    P( B, C, D, E, A, W[14] );
    P( A, B, C, D, E, W[15] );
    P( E, A, B, C, D, R(16) );
    P( D, E, A, B, C, R(17) );
    P( C, D, E, A, B, R(18) );
    P( B, C, D, E, A, R(19) );

#undef K
#undef F

#define F(x,y,z) (x ^ y ^ z)
#define K 0x6ED9EBA1

    P( A, B, C, D, E, R(20) );
    P( E, A, B, C, D, R(21) );
    P( D, E, A, B, C, R(22) );
    P( C, D, E, A, B, R(23) );
    P( B, C, D, E, A, R(24) );
    P( A, B, C, D, E, R(25) );
    P( E, A, B, C, D, R(26) );
    P( D, E, A, B, C, R(27) );
    P( C, D, E, A, B, R(28) );
    P( B, C, D, E, A, R(29) );
    P( A, B, C, D, E, R(30) );
    P( E, A, B, C, D, R(31) );
    P( D, E, A, B, C, R(32) );
    P( C, D, E, A, B, R(33) );
    P( B, C, D, E, A, R(34) );
    P( A, B, C, D, E, R(35) );
    P( E, A, B, C, D, R(36) );
    P( D, E, A, B, C, R(37) );
    P( C, D, E, A, B, R(38) );
    P( B, C, D, E, A, R(39) );

#undef K
#undef F

#define F(x,y,z) ((x & y) | (z & (x | y)))
#define K 0x8F1BBCDC

    P( A, B, C, D, E, R(40) );
    P( E, A, B, C, D, R(41) );
    P( D, E, A, B, C, R(42) );
    P( C, D, E, A, B, R(43) );
    P( B, C, D, E, A, R(44) );
    P( A, B, C, D, E, R(45) );
    P( E, A, B, C, D, R(46) );
    P( D, E, A, B, C, R(47) );
    P( C, D, E, A, B, R(48) );
    P( B, C, D, E, A, R(49) );
    P( A, B, C, D, E, R(50) );
    P( E, A, B, C, D, R(51) );
    P( D, E, A, B, C, R(52) );
    P( C, D, E, A, B, R(53) );
    P( B, C, D, E, A, R(54) );
    P( A, B, C, D, E, R(55) );
    P( E, A, B, C, D, R(56) );
    P( D, E, A, B, C, R(57) );
    P( C, D, E, A, B, R(58) );
    P( B, C, D, E, A, R(59) );

#undef K
#undef F

#define F(x,y,z) (x ^ y ^ z)
#define K 0xCA62C1D6

    P( A, B, C, D, E, R(60) );
    P( E, A, B, C, D, R(61) );
    P( D, E, A, B, C, R(62) );
    P( C, D, E, A, B, R(63) );
    P( B, C, D, E, A, R(64) );
    P( A, B, C, D, E, R(65) );
    P( E, A, B, C, D, R(66) );
    P( D, E, A, B, C, R(67) );
    P( C, D, E, A, B, R(68) );
    P( B, C, D, E, A, R(69) );
    P( A, B, C, D, E, R(70) );
    P( E, A, B, C, D, R(71) );
    P( D, E, A, B, C, R(72) );
    P( C, D, E, A, B, R(73) );
    P( B, C, D, E, A, R(74) );
    P( A, B, C, D, E, R(75) );
    P( E, A, B, C, D, R(76) );
    P( D, E, A, B, C, R(77) );
    P( C, D, E, A, B, R(78) );
    P( B, C, D, E, A, R(79) );

#undef K
#undef F

    ctx->state[0] += A;
    ctx->state[1] += B;
    ctx->state[2] += C;
    ctx->state[3] += D;
    ctx->state[4] += E;
}

void sha1_update( sha1_context *ctx, const guint8 *input, guint32 length )
{
    guint32 left, fill;

    if( ! length ) return;

    left = ctx->total[0] & 0x3F;
    fill = 64 - left;

    ctx->total[0] += length;
    ctx->total[0] &= 0xFFFFFFFF;

    if( ctx->total[0] < length )
        ctx->total[1]++;

    if( left && length >= fill )
    {
        memcpy( (void *) (ctx->buffer + left),
                (const void *) input, fill );
        sha1_process( ctx, ctx->buffer );
        length -= fill;
        input  += fill;
        left = 0;
    }

    while( length >= 64 )
    {
        sha1_process( ctx, input );
        length -= 64;
        input  += 64;
    }

    if( length )
    {
        memcpy( (void *) (ctx->buffer + left),
                (const void *) input, length );
    }
}

static guint8 sha1_padding[64] =
{
    0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
       0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
       0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
       0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};

void sha1_finish( sha1_context *ctx, guint8 digest[SHA1_DIGEST_LEN] )
{
    guint32 last, padn;
    guint32 high, low;
    guint8 msglen[8];

    high = ( ctx->total[0] >> 29 )
         | ( ctx->total[1] <<  3 );
    low  = ( ctx->total[0] <<  3 );

    PUT_UINT32( high, msglen, 0 );
    PUT_UINT32( low,  msglen, 4 );

    last = ctx->total[0] & 0x3F;
    padn = ( last < 56 ) ? ( 56 - last ) : ( 120 - last );

    sha1_update( ctx, sha1_padding, padn );
    sha1_update( ctx, msglen, 8 );

    PUT_UINT32( ctx->state[0], digest,  0 );
    PUT_UINT32( ctx->state[1], digest,  4 );
    PUT_UINT32( ctx->state[2], digest,  8 );
    PUT_UINT32( ctx->state[3], digest, 12 );
    PUT_UINT32( ctx->state[4], digest, 16 );
}

void sha1_hmac_starts( sha1_hmac_context *hctx, const guint8 *key, guint32 keylen )
{
    guint32 i;
    guint8 k_ipad[64];

    memset( k_ipad, 0x36, 64 );
    memset( hctx->k_opad, 0x5C, 64 );

    for( i = 0; i < keylen; i++ )
    {
        if( i >= 64 ) break;

        k_ipad[i] ^= key[i];
        hctx->k_opad[i] ^= key[i];
    }

    sha1_starts( &hctx->ctx );
    sha1_update( &hctx->ctx, k_ipad, 64 );
}

void sha1_hmac_update( sha1_hmac_context *hctx, const guint8 *buf, guint32 buflen )
{
    sha1_update( &hctx->ctx, buf, buflen );
}

void sha1_hmac_finish( sha1_hmac_context *hctx, guint8 digest[SHA1_DIGEST_LEN] )
{
    guint8 tmpbuf[SHA1_DIGEST_LEN];

    sha1_finish( &hctx->ctx, tmpbuf );

    sha1_starts( &hctx->ctx );
    sha1_update( &hctx->ctx, hctx->k_opad, 64 );
    sha1_update( &hctx->ctx, tmpbuf, SHA1_DIGEST_LEN );
    sha1_finish( &hctx->ctx, digest );
}

void sha1_hmac( const guint8 *key, guint32 keylen, const guint8 *buf, guint32 buflen,
                guint8 digest[SHA1_DIGEST_LEN] )
{
    sha1_hmac_context hctx;

    sha1_hmac_starts( &hctx, key, keylen );
    sha1_hmac_update( &hctx, buf, buflen );
    sha1_hmac_finish( &hctx, digest );
}

#ifdef TEST

#include <stdlib.h>
#include <stdio.h>
#include <errno.h>

/*
 * those are the standard FIPS-180-1 test vectors
 */

static const char *msg[] =
{
    "abc",
    "abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq",
    NULL
};

static const char *val[] =
{
    "a9993e364706816aba3e25717850c26c9cd0d89d",
    "84983e441c3bd26ebaae4aa1f95129e5e54670f1",
    "34aa973cd4c4daa4f61eeb2bdbad27316534016f"
};

int main( int argc, char *argv[] )
{
    FILE *f;
    int i, j;
    char output[41];
    sha1_context ctx;
    unsigned char buf[1000];
    unsigned char sha1sum[SHA1_DIGEST_LEN];

    if( argc < 2 )
    {
        printf( "\n SHA-1 Validation Tests:\n\n" );

        for( i = 0; i < 3; i++ )
        {
            printf( " Test %d ", i + 1 );

            sha1_starts( &ctx );

            if( i < 2 )
            {
                sha1_update( &ctx, (guint8 *) msg[i],
                             strlen( msg[i] ) );
            }
            else
            {
                memset( buf, 'a', 1000 );

                for( j = 0; j < 1000; j++ )
                {
                    sha1_update( &ctx, (guint8 *) buf, 1000 );
                }
            }

            sha1_finish( &ctx, sha1sum );

            for( j = 0; j < SHA1_DIGEST_LEN; j++ )
            {
                g_snprintf( output + j * 2, 41-j*2, "%02x", sha1sum[j] );
            }

            if( memcmp( output, val[i], 40 ) )
            {
                printf( "failed!\n" );
                return( 1 );
            }

            printf( "passed.\n" );
        }

        printf( "\n" );
    }
    else
    {
        if( ! ( f = ws_fopen( argv[1], "rb" ) ) )
        {
            printf("fopen: %s", g_strerror(errno));
            return( 1 );
        }

        sha1_starts( &ctx );

        while( ( i = fread( buf, 1, sizeof( buf ), f ) ) > 0 )
        {
            sha1_update( &ctx, buf, i );
        }

        sha1_finish( &ctx, sha1sum );

        for( j = 0; j < SHA1_DIGEST_LEN; j++ )
        {
            printf( "%02x", sha1sum[j] );
        }

        printf( "  %s\n", argv[1] );
    }

    return( 0 );
}

#endif


/*
 * Editor modelines  -  http://www.wireshark.org/tools/modelines.html
 *
 * Local variables:
 * c-basic-offset: 4
 * tab-width: 8
 * indent-tabs-mode: nil
 * End:
 *
 * vi: set shiftwidth=4 tabstop=8 expandtab:
 * :indentSize=4:tabSize=8:noTabs=true:
 */
