package org.klomp.snark;
import java.io.UnsupportedEncodingException;
import java.net.URI;
import java.net.URISyntaxException;
import java.util.ArrayList;
import java.util.List;
import java.util.Locale;
import net.i2p.data.Base32;
/**
*
* @since 0.9.4 moved from I2PSnarkServlet
*/
public class MagnetURI {
private final String _tracker;
private final String _name;
private final byte[] _ih;
/** BEP 9 */
public static final String MAGNET = "magnet:";
public static final String MAGNET_FULL = MAGNET + "?xt=urn:btih:";
/** http://sponge.i2p/files/maggotspec.txt */
public static final String MAGGOT = "maggot://";
/**
* @param url non-null
*/
public MagnetURI(I2PSnarkUtil util, String url) throws IllegalArgumentException {
String ihash;
String name;
String trackerURL = null;
if (url.startsWith(MAGNET)) {
// magnet:?xt=urn:btih:0691e40aae02e552cfcb57af1dca56214680c0c5&tr=http://tracker2.postman.i2p/announce.php
String xt = getParam("xt", url);
if (xt == null || !xt.startsWith("urn:btih:"))
throw new IllegalArgumentException();
ihash = xt.substring("urn:btih:".length());
trackerURL = getTrackerParam(url);
name = util.getString("Magnet") + ' ' + ihash;
String dn = getParam("dn", url);
if (dn != null)
name += " (" + dn + ')';
} else if (url.startsWith(MAGGOT)) {
// maggot://0691e40aae02e552cfcb57af1dca56214680c0c5:0b557bbdf8718e95d352fbe994dec3a383e2ede7
ihash = url.substring(MAGGOT.length()).trim();
int col = ihash.indexOf(':');
if (col >= 0)
ihash = ihash.substring(0, col);
name = util.getString("Magnet") + ' ' + ihash;
} else {
throw new IllegalArgumentException();
}
byte[] ih = null;
if (ihash.length() == 32) {
ih = Base32.decode(ihash);
} else if (ihash.length() == 40) {
// Like DataHelper.fromHexString() but ensures no loss of leading zero bytes
ih = new byte[20];
try {
for (int i = 0; i < 20; i++) {
ih[i] = (byte) (Integer.parseInt(ihash.substring(i*2, (i*2) + 2), 16) & 0xff);
}
} catch (NumberFormatException nfe) {
ih = null;
}
}
if (ih == null || ih.length != 20)
throw new IllegalArgumentException();
_ih = ih;
_name = name;
_tracker = trackerURL;
}
/**
* @return 20 bytes or null
*/
public byte[] getInfoHash() {
return _ih;
}
/**
* @return pretty name or null, NOT HTML escaped
*/
public String getName() {
return _name;
}
/**
* @return tracker url or null
*/
public String getTrackerURL() {
return _tracker;
}
/**
* @return first decoded parameter or null
*/
private static String getParam(String key, String uri) {
int idx = uri.indexOf('?' + key + '=');
if (idx >= 0) {
idx += key.length() + 2;
} else {
idx = uri.indexOf('&' + key + '=');
if (idx >= 0)
idx += key.length() + 2;
}
if (idx < 0 || idx > uri.length())
return null;
String rv = uri.substring(idx);
idx = rv.indexOf('&');
if (idx >= 0)
rv = rv.substring(0, idx);
else
rv = rv.trim();
return decode(rv);
}
/**
* @return all decoded parameters or null
* @since 0.9.1
*/
private static List<String> getMultiParam(String key, String uri) {
int idx = uri.indexOf('?' + key + '=');
if (idx >= 0) {
idx += key.length() + 2;
} else {
idx = uri.indexOf('&' + key + '=');
if (idx >= 0)
idx += key.length() + 2;
}
if (idx < 0 || idx > uri.length())
return null;
List<String> rv = new ArrayList<String>();
while (true) {
String p = uri.substring(idx);
uri = p;
idx = p.indexOf('&');
if (idx >= 0)
p = p.substring(0, idx);
else
p = p.trim();
rv.add(decode(p));
idx = uri.indexOf('&' + key + '=');
if (idx < 0)
break;
idx += key.length() + 2;
}
return rv;
}
/**
* @return first valid I2P tracker or null
* @since 0.9.1
*/
private static String getTrackerParam(String uri) {
List<String> trackers = getMultiParam("tr", uri);
if (trackers == null)
return null;
for (String t : trackers) {
try {
URI u = new URI(t);
String protocol = u.getScheme();
String host = u.getHost();
if (protocol == null || host == null ||
!protocol.toLowerCase(Locale.US).equals("http") ||
!host.toLowerCase(Locale.US).endsWith(".i2p"))
continue;
return t;
} catch(URISyntaxException use) {}
}
return null;
}
/**
* Decode %xx encoding, convert to UTF-8 if necessary.
* Copied from i2ptunnel LocalHTTPServer.
* Also converts '+' to ' ' so the dn parameter comes out right
* These are coming in via a application/x-www-form-urlencoded form so
* the pluses are in there...
* hopefully any real + is encoded as %2B.
*
* @since 0.9.1
*/
private static String decode(String s) {
if (!(s.contains("%") || s.contains("+")))
return s;
StringBuilder buf = new StringBuilder(s.length());
boolean utf8 = false;
for (int i = 0; i < s.length(); i++) {
char c = s.charAt(i);
if (c == '+') {
buf.append(' ');
} else if (c != '%') {
buf.append(c);
} else {
try {
int val = Integer.parseInt(s.substring(++i, (++i) + 1), 16);
if ((val & 0x80) != 0)
utf8 = true;
buf.append((char) val);
} catch (IndexOutOfBoundsException ioobe) {
break;
} catch (NumberFormatException nfe) {
break;
}
}
}
if (utf8) {
try {
return new String(buf.toString().getBytes("ISO-8859-1"), "UTF-8");
} catch (UnsupportedEncodingException uee) {}
}
return buf.toString();
}
}