paulo@0: /*
paulo@0:  * $Id: gt_urn.c,v 1.4 2004/03/05 17:47:29 hipnod Exp $
paulo@0:  *
paulo@0:  * Copyright (C) 2003 giFT project (gift.sourceforge.net)
paulo@0:  *
paulo@0:  * This program is free software; you can redistribute it and/or modify it
paulo@0:  * under the terms of the GNU General Public License as published by the
paulo@0:  * Free Software Foundation; either version 2, or (at your option) any
paulo@0:  * later version.
paulo@0:  *
paulo@0:  * This program is distributed in the hope that it will be useful, but
paulo@0:  * WITHOUT ANY WARRANTY; without even the implied warranty of
paulo@0:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
paulo@0:  * General Public License for more details.
paulo@0:  */
paulo@0: 
paulo@0: #include "gt_gnutella.h"
paulo@0: #include "gt_urn.h"
paulo@0: #include "encoding/base32.h"
paulo@0: #include "sha1.h"
paulo@0: 
paulo@0: /*****************************************************************************/
paulo@0: 
paulo@0: #define URN_PREFIX_LEN        (sizeof("urn:")-1)
paulo@0: #define SHA1_PREFIX_LEN       (sizeof("sha1:")-1)
paulo@0: #define BITPRINT_PREFIX_LEN   (sizeof("bitprint:")-1)
paulo@0: 
paulo@0: /*****************************************************************************/
paulo@0: 
paulo@0: enum urn_types
paulo@0: {
paulo@0: 	GT_URN_SHA1     = 0,
paulo@0: 	GT_URN_BITPRINT = 1,   /* for now, collapse bitprint to sha1 */
paulo@0: };
paulo@0: 
paulo@0: /*****************************************************************************/
paulo@0: 
paulo@0: static long get_urn_type (gt_urn_t *urn)
paulo@0: {
paulo@0: 	long tmp;
paulo@0: 
paulo@0: 	memcpy (&tmp, urn, sizeof(tmp));
paulo@0: 	return tmp;
paulo@0: }
paulo@0: 
paulo@0: static void set_urn_type (gt_urn_t *urn, enum urn_types t)
paulo@0: {
paulo@0: 	long tmp = t;
paulo@0: 
paulo@0: 	memcpy (urn, &tmp, sizeof(tmp));
paulo@0: }
paulo@0: 
paulo@0: static unsigned char *get_urn_data (const gt_urn_t *urn)
paulo@0: {
paulo@0: 	return (unsigned char *)urn + sizeof(long);
paulo@0: }
paulo@0: 
paulo@0: static void set_urn_data (gt_urn_t *urn, const unsigned char *data, size_t len)
paulo@0: {
paulo@0: 	memcpy (get_urn_data (urn), data, len);
paulo@0: }
paulo@0: 
paulo@0: /*****************************************************************************/
paulo@0: 
paulo@0: static size_t bin_length (enum urn_types t)
paulo@0: {
paulo@0: 	switch (t)
paulo@0: 	{
paulo@0: 	 case GT_URN_BITPRINT:
paulo@0: 	 case GT_URN_SHA1: return SHA1_BINSIZE;
paulo@0: 	 default:          return 0;
paulo@0: 	}
paulo@0: }
paulo@0: 
paulo@0: static gt_urn_t *sha1_urn_new (const unsigned char *data)
paulo@0: {
paulo@0: 	gt_urn_t *new_urn;
paulo@0: 
paulo@0: 	if (!(new_urn = malloc (SHA1_BINSIZE + sizeof(long))))
paulo@0: 		return NULL;
paulo@0: 
paulo@0: 	/* put the identifier at the beginning */
paulo@0: 	set_urn_type (new_urn, GT_URN_SHA1);
paulo@0: 
paulo@0: 	/* copy the data */
paulo@0: 	set_urn_data (new_urn, data, SHA1_BINSIZE);
paulo@0: 
paulo@0: 	return new_urn;
paulo@0: }
paulo@0: 
paulo@0: gt_urn_t *gt_urn_new (const char *urn_type, const unsigned char *data)
paulo@0: {
paulo@0: 	if (!strcasecmp (urn_type, "urn:sha1"))
paulo@0: 		return sha1_urn_new (data);
paulo@0: 
paulo@0: 	return NULL;
paulo@0: }
paulo@0: 
paulo@0: unsigned char *gt_urn_data (const gt_urn_t *urn)
paulo@0: {
paulo@0: 	if (!urn)
paulo@0: 		return NULL;
paulo@0: 
paulo@0: 	return get_urn_data (urn);
paulo@0: }
paulo@0: 
paulo@0: char *gt_urn_string (const gt_urn_t *urn)
paulo@0: {
paulo@0: 	unsigned char  *data;
paulo@0: 	char           *urn_str;
paulo@0: 	const size_t    prefix_len = URN_PREFIX_LEN + SHA1_PREFIX_LEN;
paulo@0: 
paulo@0: 	/*
paulo@0: 	 * This is the same for bitprint and sha1 urns, because we convert
paulo@0: 	 * to sha1 anyway.
paulo@0: 	 */
paulo@0: 
paulo@0: 	if (!(data = gt_urn_data (urn)))
paulo@0: 		return NULL;
paulo@0: 
paulo@0: 	if (!(urn_str = malloc (prefix_len + SHA1_STRLEN + 1)))
paulo@0: 		return NULL;
paulo@0: 
paulo@0: 	memcpy (urn_str, "urn:sha1:", prefix_len);
paulo@0: 	gt_base32_encode (data, SHA1_BINSIZE, urn_str + prefix_len, SHA1_STRLEN);
paulo@0: 
paulo@0: 	urn_str[prefix_len + SHA1_STRLEN] = 0;
paulo@0: 
paulo@0: 	return urn_str;
paulo@0: }
paulo@0: 
paulo@0: /*****************************************************************************/
paulo@0: 
paulo@0: static gt_urn_t *sha1_urn_parse (const char *base32)
paulo@0: {
paulo@0: 	gt_urn_t *bin;
paulo@0: 
paulo@0: 	/* make sure the hash is the right length */
paulo@0: 	if (!gt_base32_valid (base32, SHA1_STRLEN))
paulo@0: 		return NULL;
paulo@0: 
paulo@0: 	if (!(bin = malloc (SHA1_BINSIZE + sizeof(long))))
paulo@0: 		return NULL;
paulo@0: 
paulo@0: 	gt_base32_decode (base32, SHA1_STRLEN, bin + sizeof(long), SHA1_BINSIZE);
paulo@0: 	set_urn_type (bin, GT_URN_SHA1);
paulo@0: 
paulo@0: 	return bin;
paulo@0: }
paulo@0: 
paulo@0: /*
paulo@0:  * Bitprint urns are the format:
paulo@0:  *
paulo@0:  *      urn:bitprint:[32-character SHA1].[39-character TigerTree]
paulo@0:  *
paulo@0:  * We use the sha1 parsing and truncate the tigertree for now.
paulo@0:  */
paulo@0: static gt_urn_t *bitprint_urn_parse (const char *base32)
paulo@0: {
paulo@0: 	return sha1_urn_parse (base32);
paulo@0: }
paulo@0: 
paulo@0: gt_urn_t *gt_urn_parse (const char *str)
paulo@0: {
paulo@0: 	if (strncasecmp ("urn:", str, URN_PREFIX_LEN) != 0)
paulo@0: 		return NULL;
paulo@0: 
paulo@0: 	str += URN_PREFIX_LEN;
paulo@0: 
paulo@0: 	if (!strncasecmp (str, "sha1:", SHA1_PREFIX_LEN))
paulo@0: 		return sha1_urn_parse (str + SHA1_PREFIX_LEN);
paulo@0: 
paulo@0: 	if (!strncasecmp (str, "bitprint:", BITPRINT_PREFIX_LEN))
paulo@0: 		return bitprint_urn_parse (str + BITPRINT_PREFIX_LEN);
paulo@0: 
paulo@0: 	return NULL;
paulo@0: }
paulo@0: 
paulo@0: /*****************************************************************************/
paulo@0: 
paulo@0: int gt_urn_cmp (gt_urn_t *a, gt_urn_t *b)
paulo@0: {
paulo@0: 	int ret;
paulo@0: 
paulo@0: 	if (!a || !b)
paulo@0: 		return -1;
paulo@0: 
paulo@0: 	if ((ret = memcmp (a, b, 4)))
paulo@0: 		return ret;
paulo@0: 
paulo@0: 	return memcmp (a + sizeof(long), b + sizeof(long),
paulo@0: 	               bin_length (get_urn_type (a)));
paulo@0: }