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  • only in /netgear-R7000-V1.0.7.12_1.2.5/ap/gpl/transmission/transmission-2.73/libtransmission/
1/*
2 * This file Copyright (C) Mnemosyne LLC
3 *
4 * This file is licensed by the GPL version 2. Works owned by the
5 * Transmission project are granted a special exemption to clause 2(b)
6 * so that the bulk of its code can remain under the MIT license.
7 * This exemption does not extend to derived works not owned by
8 * the Transmission project.
9 *
10 * $Id: magnet.c 13546 2012-10-05 16:10:12Z jordan $
11 */
12
13#include <assert.h>
14#include <string.h> /* strchr() */
15#include <stdio.h> /* sscanf() */
16
17#include "transmission.h"
18#include "bencode.h"
19#include "magnet.h"
20#include "utils.h"
21#include "web.h"
22
23/***
24****
25***/
26
27/* this base32 code converted from code by Robert Kaye and Gordon Mohr
28 * and is public domain. see http://bitzi.com/publicdomain for more info */
29
30static const int base32Lookup[] =
31{
32    0xFF,0xFF,0x1A,0x1B,0x1C,0x1D,0x1E,0x1F, /* '0', '1', '2', '3', '4', '5', '6', '7' */
33    0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF, /* '8', '9', ':', ';', '<', '=', '>', '?' */
34    0xFF,0x00,0x01,0x02,0x03,0x04,0x05,0x06, /* '@', 'A', 'B', 'C', 'D', 'E', 'F', 'G' */
35    0x07,0x08,0x09,0x0A,0x0B,0x0C,0x0D,0x0E, /* 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O' */
36    0x0F,0x10,0x11,0x12,0x13,0x14,0x15,0x16, /* 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W' */
37    0x17,0x18,0x19,0xFF,0xFF,0xFF,0xFF,0xFF, /* 'X', 'Y', 'Z', '[', '\', ']', '^', '_' */
38    0xFF,0x00,0x01,0x02,0x03,0x04,0x05,0x06, /* '`', 'a', 'b', 'c', 'd', 'e', 'f', 'g' */
39    0x07,0x08,0x09,0x0A,0x0B,0x0C,0x0D,0x0E, /* 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o' */
40    0x0F,0x10,0x11,0x12,0x13,0x14,0x15,0x16, /* 'p', 'q', 'r', 's', 't', 'u', 'v', 'w' */
41    0x17,0x18,0x19,0xFF,0xFF,0xFF,0xFF,0xFF  /* 'x', 'y', 'z', '{', '|', '}', '~', 'DEL' */
42};
43
44static const int base32LookupLen = sizeof( base32Lookup ) / sizeof( base32Lookup[0] );
45
46static void
47base32_to_sha1( uint8_t * out, const char * in, const int inlen )
48{
49    const int outlen = 20;
50    int i, index, offset;
51
52    memset( out, 0, 20 );
53
54    assert( inlen == 32 );
55
56    for( i=0, index=0, offset=0; i<inlen; ++i )
57    {
58        int digit;
59        int lookup = in[i] - '0';
60
61        /* Skip chars outside the lookup table */
62        if( lookup<0 || lookup>=base32LookupLen )
63            continue;
64
65        /* If this digit is not in the table, ignore it */
66        digit = base32Lookup[lookup];
67        if( digit == 0xFF )
68            continue;
69
70        if( index <= 3 ) {
71            index = (index + 5) % 8;
72            if( index == 0 ) {
73                out[offset] |= digit;
74                offset++;
75                if( offset >= outlen )
76                    break;
77            } else {
78                out[offset] |= digit << (8 - index);
79            }
80        } else {
81            index = (index + 5) % 8;
82            out[offset] |= (digit >> index);
83            offset++;
84
85            if( offset >= outlen )
86                break;
87            out[offset] |= digit << (8 - index);
88       }
89   }
90}
91
92/***
93****
94***/
95
96#define MAX_TRACKERS 64
97#define MAX_WEBSEEDS 64
98
99tr_magnet_info *
100tr_magnetParse( const char * uri )
101{
102    bool got_checksum = false;
103    int trCount = 0;
104    int wsCount = 0;
105    char * tr[MAX_TRACKERS];
106    char * ws[MAX_WEBSEEDS];
107    char * displayName = NULL;
108    uint8_t sha1[SHA_DIGEST_LENGTH];
109    tr_magnet_info * info = NULL;
110
111    if( ( uri != NULL ) && !memcmp( uri, "magnet:?", 8 ) )
112    {
113        const char * walk;
114
115        for( walk=uri+8; walk && *walk; )
116        {
117            const char * key = walk;
118            const char * delim = strchr( key, '=' );
119            const char * val = delim == NULL ? NULL : delim + 1;
120            const char * next = strchr( delim == NULL ? key : val, '&' );
121            int keylen, vallen;
122
123            if( delim != NULL )
124                keylen = delim - key;
125            else if( next != NULL )
126                keylen = next - key;
127            else
128                keylen = strlen( key );
129
130            if( val == NULL )
131                vallen = 0;
132            else if( next != NULL )
133                vallen = next - val;
134            else
135                vallen = strlen( val );
136
137            if( ( keylen==2 ) && !memcmp( key, "xt", 2 ) && val && !memcmp( val, "urn:btih:", 9 ) )
138            {
139                const char * hash = val + 9;
140                const int hashlen = vallen - 9;
141
142                if( hashlen == 40 ) {
143                    tr_hex_to_sha1( sha1, hash );
144                    got_checksum = true;
145                }
146                else if( hashlen == 32 ) {
147                    base32_to_sha1( sha1, hash, hashlen );
148                    got_checksum = true;
149                }
150            }
151
152            if( ( vallen > 0 ) && ( keylen==2 ) && !memcmp( key, "dn", 2 ) )
153                displayName = tr_http_unescape( val, vallen );
154
155            if( ( vallen > 0 ) && ( trCount < MAX_TRACKERS ) ) {
156                int i;
157                if( ( keylen==2 ) && !memcmp( key, "tr", 2 ) )
158                    tr[trCount++] = tr_http_unescape( val, vallen );
159                else if( ( sscanf( key, "tr.%d=", &i ) == 1 ) && ( i > 0 ) ) /* ticket #3341 */
160                    tr[trCount++] = tr_http_unescape( val, vallen );
161            }
162
163            if( ( vallen > 0 ) && ( keylen==2 ) && !memcmp( key, "ws", 2 ) && ( wsCount < MAX_WEBSEEDS ) )
164                ws[wsCount++] = tr_http_unescape( val, vallen );
165
166            walk = next != NULL ? next + 1 : NULL;
167        }
168    }
169
170    if( got_checksum )
171    {
172        info = tr_new0( tr_magnet_info, 1 );
173        info->displayName = displayName;
174        info->trackerCount = trCount;
175        info->trackers = tr_memdup( tr, sizeof(char*) * trCount );
176        info->webseedCount = wsCount;
177        info->webseeds = tr_memdup( ws, sizeof(char*) * wsCount );
178        memcpy( info->hash, sha1, sizeof(uint8_t) * SHA_DIGEST_LENGTH );
179    }
180
181    return info;
182}
183
184void
185tr_magnetFree( tr_magnet_info * info )
186{
187    if( info != NULL )
188    {
189        int i;
190
191        for( i=0; i<info->trackerCount; ++i )
192            tr_free( info->trackers[i] );
193        tr_free( info->trackers );
194
195        for( i=0; i<info->webseedCount; ++i )
196            tr_free( info->webseeds[i] );
197        tr_free( info->webseeds );
198
199        tr_free( info->displayName );
200        tr_free( info );
201    }
202}
203
204void
205tr_magnetCreateMetainfo( const tr_magnet_info * info, tr_benc * top )
206{
207    int i;
208    tr_benc * d;
209    tr_bencInitDict( top, 4 );
210
211    /* announce list */
212    if( info->trackerCount == 1 )
213        tr_bencDictAddStr( top, "announce", info->trackers[0] );
214    else {
215        tr_benc * trackers = tr_bencDictAddList( top, "announce-list", info->trackerCount );
216        for( i=0; i<info->trackerCount; ++i )
217            tr_bencListAddStr( tr_bencListAddList( trackers, 1 ), info->trackers[i] );
218    }
219
220    /* webseeds */
221    if( info->webseedCount > 0 ) {
222        tr_benc * urls = tr_bencDictAddList( top, "url-list", info->webseedCount );
223        for( i=0; i<info->webseedCount; ++i )
224            tr_bencListAddStr( urls, info->webseeds[i] );
225    }
226
227    /* nonstandard keys */
228    d = tr_bencDictAddDict( top, "magnet-info", 2 );
229    tr_bencDictAddRaw( d, "info_hash", info->hash, 20 );
230    if( info->displayName != NULL )
231        tr_bencDictAddStr( d, "display-name", info->displayName );
232}
233
234
235