1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/src/gt_urn.c	Sat Feb 20 21:18:28 2010 -0800
     1.3 @@ -0,0 +1,193 @@
     1.4 +/*
     1.5 + * $Id: gt_urn.c,v 1.4 2004/03/05 17:47:29 hipnod Exp $
     1.6 + *
     1.7 + * Copyright (C) 2003 giFT project (gift.sourceforge.net)
     1.8 + *
     1.9 + * This program is free software; you can redistribute it and/or modify it
    1.10 + * under the terms of the GNU General Public License as published by the
    1.11 + * Free Software Foundation; either version 2, or (at your option) any
    1.12 + * later version.
    1.13 + *
    1.14 + * This program is distributed in the hope that it will be useful, but
    1.15 + * WITHOUT ANY WARRANTY; without even the implied warranty of
    1.16 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    1.17 + * General Public License for more details.
    1.18 + */
    1.19 +
    1.20 +#include "gt_gnutella.h"
    1.21 +#include "gt_urn.h"
    1.22 +#include "encoding/base32.h"
    1.23 +#include "sha1.h"
    1.24 +
    1.25 +/*****************************************************************************/
    1.26 +
    1.27 +#define URN_PREFIX_LEN        (sizeof("urn:")-1)
    1.28 +#define SHA1_PREFIX_LEN       (sizeof("sha1:")-1)
    1.29 +#define BITPRINT_PREFIX_LEN   (sizeof("bitprint:")-1)
    1.30 +
    1.31 +/*****************************************************************************/
    1.32 +
    1.33 +enum urn_types
    1.34 +{
    1.35 +	GT_URN_SHA1     = 0,
    1.36 +	GT_URN_BITPRINT = 1,   /* for now, collapse bitprint to sha1 */
    1.37 +};
    1.38 +
    1.39 +/*****************************************************************************/
    1.40 +
    1.41 +static long get_urn_type (gt_urn_t *urn)
    1.42 +{
    1.43 +	long tmp;
    1.44 +
    1.45 +	memcpy (&tmp, urn, sizeof(tmp));
    1.46 +	return tmp;
    1.47 +}
    1.48 +
    1.49 +static void set_urn_type (gt_urn_t *urn, enum urn_types t)
    1.50 +{
    1.51 +	long tmp = t;
    1.52 +
    1.53 +	memcpy (urn, &tmp, sizeof(tmp));
    1.54 +}
    1.55 +
    1.56 +static unsigned char *get_urn_data (const gt_urn_t *urn)
    1.57 +{
    1.58 +	return (unsigned char *)urn + sizeof(long);
    1.59 +}
    1.60 +
    1.61 +static void set_urn_data (gt_urn_t *urn, const unsigned char *data, size_t len)
    1.62 +{
    1.63 +	memcpy (get_urn_data (urn), data, len);
    1.64 +}
    1.65 +
    1.66 +/*****************************************************************************/
    1.67 +
    1.68 +static size_t bin_length (enum urn_types t)
    1.69 +{
    1.70 +	switch (t)
    1.71 +	{
    1.72 +	 case GT_URN_BITPRINT:
    1.73 +	 case GT_URN_SHA1: return SHA1_BINSIZE;
    1.74 +	 default:          return 0;
    1.75 +	}
    1.76 +}
    1.77 +
    1.78 +static gt_urn_t *sha1_urn_new (const unsigned char *data)
    1.79 +{
    1.80 +	gt_urn_t *new_urn;
    1.81 +
    1.82 +	if (!(new_urn = malloc (SHA1_BINSIZE + sizeof(long))))
    1.83 +		return NULL;
    1.84 +
    1.85 +	/* put the identifier at the beginning */
    1.86 +	set_urn_type (new_urn, GT_URN_SHA1);
    1.87 +
    1.88 +	/* copy the data */
    1.89 +	set_urn_data (new_urn, data, SHA1_BINSIZE);
    1.90 +
    1.91 +	return new_urn;
    1.92 +}
    1.93 +
    1.94 +gt_urn_t *gt_urn_new (const char *urn_type, const unsigned char *data)
    1.95 +{
    1.96 +	if (!strcasecmp (urn_type, "urn:sha1"))
    1.97 +		return sha1_urn_new (data);
    1.98 +
    1.99 +	return NULL;
   1.100 +}
   1.101 +
   1.102 +unsigned char *gt_urn_data (const gt_urn_t *urn)
   1.103 +{
   1.104 +	if (!urn)
   1.105 +		return NULL;
   1.106 +
   1.107 +	return get_urn_data (urn);
   1.108 +}
   1.109 +
   1.110 +char *gt_urn_string (const gt_urn_t *urn)
   1.111 +{
   1.112 +	unsigned char  *data;
   1.113 +	char           *urn_str;
   1.114 +	const size_t    prefix_len = URN_PREFIX_LEN + SHA1_PREFIX_LEN;
   1.115 +
   1.116 +	/*
   1.117 +	 * This is the same for bitprint and sha1 urns, because we convert
   1.118 +	 * to sha1 anyway.
   1.119 +	 */
   1.120 +
   1.121 +	if (!(data = gt_urn_data (urn)))
   1.122 +		return NULL;
   1.123 +
   1.124 +	if (!(urn_str = malloc (prefix_len + SHA1_STRLEN + 1)))
   1.125 +		return NULL;
   1.126 +
   1.127 +	memcpy (urn_str, "urn:sha1:", prefix_len);
   1.128 +	gt_base32_encode (data, SHA1_BINSIZE, urn_str + prefix_len, SHA1_STRLEN);
   1.129 +
   1.130 +	urn_str[prefix_len + SHA1_STRLEN] = 0;
   1.131 +
   1.132 +	return urn_str;
   1.133 +}
   1.134 +
   1.135 +/*****************************************************************************/
   1.136 +
   1.137 +static gt_urn_t *sha1_urn_parse (const char *base32)
   1.138 +{
   1.139 +	gt_urn_t *bin;
   1.140 +
   1.141 +	/* make sure the hash is the right length */
   1.142 +	if (!gt_base32_valid (base32, SHA1_STRLEN))
   1.143 +		return NULL;
   1.144 +
   1.145 +	if (!(bin = malloc (SHA1_BINSIZE + sizeof(long))))
   1.146 +		return NULL;
   1.147 +
   1.148 +	gt_base32_decode (base32, SHA1_STRLEN, bin + sizeof(long), SHA1_BINSIZE);
   1.149 +	set_urn_type (bin, GT_URN_SHA1);
   1.150 +
   1.151 +	return bin;
   1.152 +}
   1.153 +
   1.154 +/*
   1.155 + * Bitprint urns are the format:
   1.156 + *
   1.157 + *      urn:bitprint:[32-character SHA1].[39-character TigerTree]
   1.158 + *
   1.159 + * We use the sha1 parsing and truncate the tigertree for now.
   1.160 + */
   1.161 +static gt_urn_t *bitprint_urn_parse (const char *base32)
   1.162 +{
   1.163 +	return sha1_urn_parse (base32);
   1.164 +}
   1.165 +
   1.166 +gt_urn_t *gt_urn_parse (const char *str)
   1.167 +{
   1.168 +	if (strncasecmp ("urn:", str, URN_PREFIX_LEN) != 0)
   1.169 +		return NULL;
   1.170 +
   1.171 +	str += URN_PREFIX_LEN;
   1.172 +
   1.173 +	if (!strncasecmp (str, "sha1:", SHA1_PREFIX_LEN))
   1.174 +		return sha1_urn_parse (str + SHA1_PREFIX_LEN);
   1.175 +
   1.176 +	if (!strncasecmp (str, "bitprint:", BITPRINT_PREFIX_LEN))
   1.177 +		return bitprint_urn_parse (str + BITPRINT_PREFIX_LEN);
   1.178 +
   1.179 +	return NULL;
   1.180 +}
   1.181 +
   1.182 +/*****************************************************************************/
   1.183 +
   1.184 +int gt_urn_cmp (gt_urn_t *a, gt_urn_t *b)
   1.185 +{
   1.186 +	int ret;
   1.187 +
   1.188 +	if (!a || !b)
   1.189 +		return -1;
   1.190 +
   1.191 +	if ((ret = memcmp (a, b, 4)))
   1.192 +		return ret;
   1.193 +
   1.194 +	return memcmp (a + sizeof(long), b + sizeof(long),
   1.195 +	               bin_length (get_urn_type (a)));
   1.196 +}