added magnet-uri functions and a base32 decode function

Jamfile

@@ -243,6 +243,7 @@ SOURCES =
 	disk_io_thread
 	enum_net
 	broadcast_socket
+	magnet_uri
 	;
 
 KADEMLIA_SOURCES =

examples/client_test.cpp

@@ -62,6 +62,7 @@ POSSIBILITY OF SUCH DAMAGE.
 #include "libtorrent/identify_client.hpp"
 #include "libtorrent/alert_types.hpp"
 #include "libtorrent/ip_filter.hpp"
+#include "libtorrent/magnet_uri.hpp"
 
 using boost::bind;
 
@@ -1049,6 +1050,7 @@ int main(int ac, char* av[])
 					out	<< "peers: " << s.num_peers << " "
 						<< "seeds: " << s.num_seeds << " "
 						<< "distributed copies: " << s.distributed_copies << "\n"
+						<< "  magnet-link: " << make_magnet_uri(h) << "\n"
 						<< "  download: " << esc("32") << (s.download_rate > 0 ? add_suffix(s.download_rate) + "/s ": "         ") << esc("0")
 						<< "(" << esc("32") << add_suffix(s.total_download) << esc("0") << ") ";
 				}

include/libtorrent/escape_string.hpp

@@ -47,6 +47,7 @@ namespace libtorrent
 	TORRENT_EXPORT std::string base64encode(std::string const& s);
 	// encodes a string using the base32 scheme
 	TORRENT_EXPORT std::string base32encode(std::string const& s);
+	TORRENT_EXPORT std::string base32decode(std::string const& s);
 
 	TORRENT_EXPORT boost::optional<std::string> url_has_argument(
 		std::string const& url, std::string argument);

include/libtorrent/magnet_uri.hpp

@@ -0,0 +1,59 @@
+/*
+
+Copyright (c) 2007, Arvid Norberg
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+    * Redistributions in binary form must reproduce the above copyright
+      notice, this list of conditions and the following disclaimer in
+      the documentation and/or other materials provided with the distribution.
+    * Neither the name of the author nor the names of its
+      contributors may be used to endorse or promote products derived
+      from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.
+
+*/
+
+#ifndef TORRENT_MAGNET_URI_HPP_INCLUDED
+#define TORRENT_MAGNET_URI_HPP_INCLUDED
+
+#include <string>
+#include "libtorrent/config.hpp"
+#include "libtorrent/torrent_handle.hpp"
+#include "libtorrent/session.hpp"
+#include <boost/filesystem/path.hpp>
+
+namespace libtorrent
+{
+	namespace fs = boost::filesystem;
+
+	struct torrent_handle;
+
+	std::string TORRENT_EXPORT make_magnet_uri(torrent_handle const& handle);
+
+	torrent_handle TORRENT_EXPORT add_magnet_uri(session& ses, std::string const& uri
+		, fs::path const& save_path
+		, storage_mode_t storage_mode = storage_mode_sparse
+		, bool paused = false
+		, storage_constructor_type sc = default_storage_constructor
+		, void* userdata = 0);
+}
+
+#endif
+

src/escape_string.cpp

@@ -38,6 +38,7 @@ POSSIBILITY OF SUCH DAMAGE.
 #include <iomanip>
 #include <cctype>
 #include <algorithm>
+#include <iostream>
 
 #include <boost/optional.hpp>
 
@@ -178,11 +179,8 @@ namespace libtorrent
 			std::fill(inbuf, inbuf+3, 0);
 
 			// read a chunk of input into inbuf
-			for (int j = 0; j < available_input; ++j)
+			std::copy(i, i + available_input, inbuf);
-			{
+			i += available_input;
-				inbuf[j] = *i;
-				++i;
-			}
 
 			// encode inbuf to outbuf
 			outbuf[0] = (inbuf[0] & 0xfc) >> 2;
@@ -223,19 +221,14 @@ namespace libtorrent
 		std::string ret;
 		for (std::string::const_iterator i = s.begin(); i != s.end();)
 		{
-			// available input is 1,2 or 3 bytes
-			// since we read 3 bytes at a time at most
 			int available_input = (std::min)(5, (int)std::distance(i, s.end()));
 
 			// clear input buffer
 			std::fill(inbuf, inbuf+5, 0);
 
 			// read a chunk of input into inbuf
-			for (int j = 0; j < available_input; ++j)
+			std::copy(i, i + available_input, inbuf);
-			{
+			i += available_input;
-				inbuf[j] = *i;
-				++i;
-			}
 
 			// encode inbuf to outbuf
 			outbuf[0] = (inbuf[0] & 0xf8) >> 3;
@@ -263,6 +256,64 @@ namespace libtorrent
 		return ret;
 	}
 
+	std::string base32decode(std::string const& s)
+	{
+		unsigned char inbuf[8];
+		unsigned char outbuf[5];
+	
+		std::string ret;
+		for (std::string::const_iterator i = s.begin(); i != s.end();)
+		{
+			int available_input = (std::min)(8, (int)std::distance(i, s.end()));
+
+			int pad_start = 0;
+			if (available_input < 8) pad_start = available_input;
+
+			// clear input buffer
+			std::fill(inbuf, inbuf+8, 0);
+			for (int j = 0; j < available_input; ++j)
+			{
+				char in = std::toupper(*i++);
+				if (in >= 'A' && in <= 'Z')
+					inbuf[j] = in - 'A';
+				else if (in >= '2' && in <= '7')
+					inbuf[j] = in - '2' + ('Z' - 'A') + 1;
+				else if (in == '=')
+				{
+					inbuf[j] = 0;
+					if (pad_start == 0) pad_start = j;
+				}
+				else if (in == '1')
+					inbuf[j] = 'I' - 'A';
+				else
+					return std::string();
+				TORRENT_ASSERT(inbuf[j] == (inbuf[j] & 0x1f));
+			}
+
+			// decode inbuf to outbuf
+			outbuf[0] = inbuf[0] << 3;
+			outbuf[0] |= inbuf[1] >> 2;
+			outbuf[1] = (inbuf[1] & 0x3) << 6;
+			outbuf[1] |= inbuf[2] << 1;
+			outbuf[1] |= (inbuf[3] & 0x10) >> 4;
+			outbuf[2] = (inbuf[3] & 0x0f) << 4;
+			outbuf[2] |= (inbuf[4] & 0x1e) >> 1;
+			outbuf[3] = (inbuf[4] & 0x01) << 7;
+			outbuf[3] |= (inbuf[5] & 0x1f) << 2;
+			outbuf[3] |= (inbuf[6] & 0x18) >> 3;
+			outbuf[4] = (inbuf[6] & 0x07) << 5;
+			outbuf[4] |= inbuf[7];
+
+			int input_output_mapping[] = {5, 1, 1, 2, 2, 3, 4, 4, 5};
+			int num_out = input_output_mapping[pad_start];
+
+			// write output
+			std::copy(outbuf, outbuf + num_out, std::back_inserter(ret));
+		}
+		std::cerr << " base32decode(): " << ret << std::endl;
+		return ret;
+	}
+
 	boost::optional<std::string> url_has_argument(
 		std::string const& url, std::string argument)
 	{

src/magnet_uri.cpp

@@ -0,0 +1,99 @@
+/*
+
+Copyright (c) 2007, Arvid Norberg
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+    * Redistributions in binary form must reproduce the above copyright
+      notice, this list of conditions and the following disclaimer in
+      the documentation and/or other materials provided with the distribution.
+    * Neither the name of the author nor the names of its
+      contributors may be used to endorse or promote products derived
+      from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.
+
+*/
+
+#include "libtorrent/magnet_uri.hpp"
+#include "libtorrent/session.hpp"
+#include "libtorrent/torrent_handle.hpp"
+#include "libtorrent/escape_string.hpp"
+
+#include <string>
+#include <sstream>
+
+namespace libtorrent
+{
+	std::string make_magnet_uri(torrent_handle const& handle)
+	{
+		std::stringstream ret;
+		if (!handle.is_valid()) return ret.str();
+
+		std::string name = handle.name();
+
+		ret << "magnet:?xt=urn:btih:" << base32encode((char*)handle.info_hash().begin());
+		if (!name.empty())
+			ret << "&dn=" << escape_string(name.c_str(), name.length());
+		torrent_status st = handle.status();
+		if (!st.current_tracker.empty())
+		{
+			ret << "&tr=" << escape_string(st.current_tracker.c_str()
+				, st.current_tracker.length());
+		}
+		else
+		{
+			std::vector<announce_entry> const& tr = handle.trackers();
+			if (!tr.empty())
+			{
+				ret << "&tr=" << escape_string(tr[0].url.c_str()
+					, tr[0].url.length());
+			}
+		}
+		return ret.str();
+	}
+
+	torrent_handle add_magnet_uri(session& ses, std::string const& uri
+		, fs::path const& save_path
+		, storage_mode_t storage_mode
+		, bool paused
+		, storage_constructor_type sc
+		, void* userdata)
+	{
+		std::string name;
+		std::string tracker;
+
+		boost::optional<std::string> display_name = url_has_argument(uri, "dn");
+		if (display_name) name = unescape_string(display_name->c_str());
+		boost::optional<std::string> tracker_string = url_has_argument(uri, "tr");
+		if (tracker_string) tracker = unescape_string(tracker_string->c_str());
+	
+		boost::optional<std::string> btih = url_has_argument(uri, "xt");
+		if (!btih) return torrent_handle();
+
+		if (btih->compare(0, 9, "urn:btih:") != 0) return torrent_handle();
+
+		sha1_hash info_hash(base32decode(btih->substr(9)));
+
+		return ses.add_torrent(tracker.empty() ? 0 : tracker.c_str(), info_hash
+			, name.empty() ? 0 : name.c_str(), save_path, entry()
+			, storage_mode, paused, sc, userdata);
+	}
+}
+
+

test/test_primitives.cpp

@@ -101,6 +101,25 @@ int test_main()
    TEST_CHECK(base32encode("fooba") == "MZXW6YTB");
    TEST_CHECK(base32encode("foobar") == "MZXW6YTBOI======");
 
+   TEST_CHECK(base32decode("") == "");
+   TEST_CHECK(base32decode("MY======") == "f");
+   TEST_CHECK(base32decode("MZXQ====") == "fo");
+   TEST_CHECK(base32decode("MZXW6===") == "foo");
+   TEST_CHECK(base32decode("MZXW6YQ=") == "foob");
+   TEST_CHECK(base32decode("MZXW6YTB") == "fooba");
+   TEST_CHECK(base32decode("MZXW6YTBOI======") == "foobar");
+
+   TEST_CHECK(base32decode("MY") == "f");
+   TEST_CHECK(base32decode("MZXW6YQ") == "foob");
+   TEST_CHECK(base32decode("MZXW6YTBOI") == "foobar");
+   TEST_CHECK(base32decode("mZXw6yTBO1======") == "foobar");
+
+	std::string test;
+	for (int i = 0; i < 255; ++i)
+		test += char(i);
+
+	TEST_CHECK(base32decode(base32encode(test)) == test);
+
 	// url_has_argument
 
 	TEST_CHECK(!url_has_argument("http://127.0.0.1/test", "test"));