/*
 *	cook - file construction tool
 *	Copyright (C) 1994, 2003 Peter Miller.
 *	All rights reserved.
 *
 *	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., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
 *
 * MANIFEST: functions to manipulate combined fingerprints
 *
 * Derived from code marked:
 *	Daniel J. Bernstein, brnstnd@nyu.edu.
 *	930708: fprintfile 0.95. Public domain.
 *	930708: Added fingerprintfile_addn.
 *	930622: Split off fprintfmt.c.
 *	930601: Baseline, fprintfile 0.8. Public domain.
 *	No known patent problems.
 */

#include <error.h>
#include <fp/combined.h>
#include <fp/crc32.h>
#include <fp/len.h>
#include <fp/md5.h>
#include <fp/snefru.h>

typedef struct combined_ty combined_ty;
struct combined_ty
{
    FINGERPRINT_BASE_CLASS
    fingerprint_ty  *snefru;
    fingerprint_ty  *md5;
    fingerprint_ty  *crc32;
    fingerprint_ty  *len;
};


static void
combined_constructor(fingerprint_ty *p)
{
    combined_ty     *f;

    f = (combined_ty *)p;
    f->snefru = fingerprint_new(&fp_snefru);
    f->md5 = fingerprint_new(&fp_md5);
    f->crc32 = fingerprint_new(&fp_crc32);
    f->len = fingerprint_new(&fp_len);
}


static void
combined_destructor(fingerprint_ty *p)
{
    combined_ty     *f;

    f = (combined_ty *)p;
    fingerprint_delete(f->snefru);
    fingerprint_delete(f->md5);
    fingerprint_delete(f->crc32);
    fingerprint_delete(f->len);
}


static void
combined_addn(fingerprint_ty *p, unsigned char *s, size_t n)
{
    combined_ty     *f;

    f = (combined_ty *)p;
    fingerprint_addn(f->snefru, s, n);
    fingerprint_addn(f->md5, s, n);
    fingerprint_addn(f->crc32, s, n);
    fingerprint_addn(f->len, s, n);
}


static int
combined_hash(fingerprint_ty *p, unsigned char *h)
{
    combined_ty     *f;
    int		    nbytes;
    unsigned char   *obuf;

    f = (combined_ty *)p;
    obuf = h;
    nbytes = fingerprint_hash(f->snefru, h);
    h += nbytes;
    nbytes = fingerprint_hash(f->md5, h);
    h += nbytes;
    nbytes = fingerprint_hash(f->crc32, h);
    h += nbytes;
    nbytes = fingerprint_hash(f->len, h);
    h += nbytes;
    return (h - obuf);
}


static char base64sane[] =
	"0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ:.";


static void
combined_sum(fingerprint_ty *p, char *s)
{
    unsigned char   h[1024];
    int		    i;
    unsigned long   x;
    int		    nbytes;

    nbytes = combined_hash(p, h);
    assert(nbytes == 57);

    for (i = 0; i < 19; ++i)
    {
	x = (h[3 * i] + 256L * (h[3 * i + 1] + 256L * h[3 * i + 2]));
	s[(12 * i) % 76] = base64sane[x & 63];
	x /= 64;
	s[(12 * i + 41) % 76] = base64sane[x & 63];
	x /= 64;
	s[(12 * i + 6) % 76] = base64sane[x & 63];
	x /= 64;
	s[(12 * i + 47) % 76] = base64sane[x & 63];
    }
    s[76] = 0;
}


fingerprint_methods_ty fp_combined =
{
    sizeof(combined_ty),
    "fingerprint",
    combined_constructor,
    combined_destructor,
    combined_addn,
    combined_hash,
    combined_sum
};
