Refactor authentication code

This commit is contained in:
Sam Whited 2014-11-12 10:15:38 -05:00
parent e555fe4b03
commit 14cfb60952
5 changed files with 145 additions and 88 deletions

View File

@ -0,0 +1,72 @@
package eu.siacs.conversations.crypto.sasl;
import android.util.Base64;
import java.math.BigInteger;
import java.nio.charset.Charset;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import eu.siacs.conversations.entities.Account;
import eu.siacs.conversations.utils.CryptoHelper;
import eu.siacs.conversations.xml.TagWriter;
public class DigestMd5 extends SaslMechanism {
public DigestMd5(final TagWriter tagWriter, final Account account, final SecureRandom rng) {
super(tagWriter, account, rng);
}
@Override
public String getMechanism() {
return "DIGEST-MD5";
}
@Override
public String getResponse(final String challenge) {
final String encodedResponse;
try {
final String[] challengeParts = new String(Base64.decode(challenge,
Base64.DEFAULT)).split(",");
String nonce = "";
for (int i = 0; i < challengeParts.length; ++i) {
String[] parts = challengeParts[i].split("=");
if (parts[0].equals("nonce")) {
nonce = parts[1].replace("\"", "");
} else if (parts[0].equals("rspauth")) {
return "";
}
}
final String digestUri = "xmpp/" + account.getServer();
final String nonceCount = "00000001";
final String x = account.getUsername() + ":" + account.getServer() + ":"
+ account.getPassword();
final MessageDigest md = MessageDigest.getInstance("MD5");
final byte[] y = md.digest(x.getBytes(Charset.defaultCharset()));
final String cNonce = new BigInteger(100, rng).toString(32);
final byte[] a1 = CryptoHelper.concatenateByteArrays(y,
(":" + nonce + ":" + cNonce).getBytes(Charset
.defaultCharset()));
final String a2 = "AUTHENTICATE:" + digestUri;
final String ha1 = CryptoHelper.bytesToHex(md.digest(a1));
final String ha2 = CryptoHelper.bytesToHex(md.digest(a2.getBytes(Charset
.defaultCharset())));
final String kd = ha1 + ":" + nonce + ":" + nonceCount + ":" + cNonce
+ ":auth:" + ha2;
final String response = CryptoHelper.bytesToHex(md.digest(kd.getBytes(Charset
.defaultCharset())));
final String saslString = "username=\"" + account.getUsername()
+ "\",realm=\"" + account.getServer() + "\",nonce=\""
+ nonce + "\",cnonce=\"" + cNonce + "\",nc=" + nonceCount
+ ",qop=auth,digest-uri=\"" + digestUri + "\",response="
+ response + ",charset=utf-8";
encodedResponse = Base64.encodeToString(
saslString.getBytes(Charset.defaultCharset()),
Base64.NO_WRAP);
} catch (final NoSuchAlgorithmException e) {
return "";
}
return encodedResponse;
}
}

View File

@ -0,0 +1,25 @@
package eu.siacs.conversations.crypto.sasl;
import android.util.Base64;
import java.nio.charset.Charset;
import eu.siacs.conversations.entities.Account;
import eu.siacs.conversations.xml.TagWriter;
public class Plain extends SaslMechanism {
public Plain(final TagWriter tagWriter, final Account account) {
super(tagWriter, account, null);
}
@Override
public String getMechanism() {
return "PLAIN";
}
@Override
public String getStartAuth() {
final String sasl = '\u0000' + account.getUsername() + '\u0000' + account.getPassword();
return Base64.encodeToString(sasl.getBytes(Charset.defaultCharset()), Base64.NO_WRAP);
}
}

View File

@ -0,0 +1,27 @@
package eu.siacs.conversations.crypto.sasl;
import java.security.SecureRandom;
import eu.siacs.conversations.entities.Account;
import eu.siacs.conversations.xml.TagWriter;
public abstract class SaslMechanism {
final protected TagWriter tagWriter;
final protected Account account;
final protected SecureRandom rng;
public SaslMechanism(final TagWriter tagWriter, final Account account, final SecureRandom rng) {
this.tagWriter = tagWriter;
this.account = account;
this.rng = rng;
}
public abstract String getMechanism();
public String getStartAuth() {
return "";
}
public String getResponse(final String challenge) {
return "";
}
}

View File

@ -1,14 +1,7 @@
package eu.siacs.conversations.utils;
import java.math.BigInteger;
import java.nio.charset.Charset;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import eu.siacs.conversations.entities.Account;
import android.util.Base64;
public class CryptoHelper {
public static final String FILETRANSFER = "?FILETRANSFERv1:";
final protected static char[] hexArray = "0123456789abcdef".toCharArray();
@ -36,64 +29,13 @@ public class CryptoHelper {
return array;
}
public static String saslPlain(String username, String password) {
String sasl = '\u0000' + username + '\u0000' + password;
return Base64.encodeToString(sasl.getBytes(Charset.defaultCharset()),
Base64.NO_WRAP);
}
private static byte[] concatenateByteArrays(byte[] a, byte[] b) {
public static byte[] concatenateByteArrays(byte[] a, byte[] b) {
byte[] result = new byte[a.length + b.length];
System.arraycopy(a, 0, result, 0, a.length);
System.arraycopy(b, 0, result, a.length, b.length);
return result;
}
public static String saslDigestMd5(Account account, String challenge,
SecureRandom random) {
try {
String[] challengeParts = new String(Base64.decode(challenge,
Base64.DEFAULT)).split(",");
String nonce = "";
for (int i = 0; i < challengeParts.length; ++i) {
String[] parts = challengeParts[i].split("=");
if (parts[0].equals("nonce")) {
nonce = parts[1].replace("\"", "");
} else if (parts[0].equals("rspauth")) {
return null;
}
}
String digestUri = "xmpp/" + account.getServer();
String nonceCount = "00000001";
String x = account.getUsername() + ":" + account.getServer() + ":"
+ account.getPassword();
MessageDigest md = MessageDigest.getInstance("MD5");
byte[] y = md.digest(x.getBytes(Charset.defaultCharset()));
String cNonce = new BigInteger(100, random).toString(32);
byte[] a1 = concatenateByteArrays(y,
(":" + nonce + ":" + cNonce).getBytes(Charset
.defaultCharset()));
String a2 = "AUTHENTICATE:" + digestUri;
String ha1 = bytesToHex(md.digest(a1));
String ha2 = bytesToHex(md.digest(a2.getBytes(Charset
.defaultCharset())));
String kd = ha1 + ":" + nonce + ":" + nonceCount + ":" + cNonce
+ ":auth:" + ha2;
String response = bytesToHex(md.digest(kd.getBytes(Charset
.defaultCharset())));
String saslString = "username=\"" + account.getUsername()
+ "\",realm=\"" + account.getServer() + "\",nonce=\""
+ nonce + "\",cnonce=\"" + cNonce + "\",nc=" + nonceCount
+ ",qop=auth,digest-uri=\"" + digestUri + "\",response="
+ response + ",charset=utf-8";
return Base64.encodeToString(
saslString.getBytes(Charset.defaultCharset()),
Base64.NO_WRAP);
} catch (NoSuchAlgorithmException e) {
return null;
}
}
public static String randomMucName(SecureRandom random) {
return randomWord(3, random) + "." + randomWord(7, random);
}

View File

@ -39,9 +39,11 @@ import javax.net.ssl.SSLSocketFactory;
import javax.net.ssl.X509TrustManager;
import eu.siacs.conversations.Config;
import eu.siacs.conversations.crypto.sasl.DigestMd5;
import eu.siacs.conversations.crypto.sasl.Plain;
import eu.siacs.conversations.crypto.sasl.SaslMechanism;
import eu.siacs.conversations.entities.Account;
import eu.siacs.conversations.services.XmppConnectionService;
import eu.siacs.conversations.utils.CryptoHelper;
import eu.siacs.conversations.utils.DNSHelper;
import eu.siacs.conversations.utils.zlib.ZLibInputStream;
import eu.siacs.conversations.utils.zlib.ZLibOutputStream;
@ -104,6 +106,8 @@ public class XmppConnection implements Runnable {
private OnMessageAcknowledged acknowledgedListener = null;
private XmppConnectionService mXmppConnectionService = null;
private SaslMechanism saslMechanism;
public XmppConnection(Account account, XmppConnectionService service) {
this.account = account;
this.wakeLock = service.getPowerManager().newWakeLock(
@ -287,12 +291,11 @@ public class XmppConnection implements Runnable {
tagReader.readElement(nextTag);
changeStatus(Account.STATUS_UNAUTHORIZED);
} else if (nextTag.isStart("challenge")) {
String challange = tagReader.readElement(nextTag).getContent();
Element response = new Element("response");
final String challenge = tagReader.readElement(nextTag).getContent();
final Element response = new Element("response");
response.setAttribute("xmlns",
"urn:ietf:params:xml:ns:xmpp-sasl");
response.setContent(CryptoHelper.saslDigestMd5(account,
challange, mXmppConnectionService.getRNG()));
response.setContent(saslMechanism.getResponse(challenge));
tagWriter.writeElement(response);
} else if (nextTag.isStart("enabled")) {
Element enabled = tagReader.readElement(nextTag);
@ -592,23 +595,6 @@ public class XmppConnection implements Runnable {
}
}
private void sendSaslAuthPlain() throws IOException {
String saslString = CryptoHelper.saslPlain(account.getUsername(),
account.getPassword());
Element auth = new Element("auth");
auth.setAttribute("xmlns", "urn:ietf:params:xml:ns:xmpp-sasl");
auth.setAttribute("mechanism", "PLAIN");
auth.setContent(saslString);
tagWriter.writeElement(auth);
}
private void sendSaslAuthDigestMd5() throws IOException {
Element auth = new Element("auth");
auth.setAttribute("xmlns", "urn:ietf:params:xml:ns:xmpp-sasl");
auth.setAttribute("mechanism", "DIGEST-MD5");
tagWriter.writeElement(auth);
}
private void processStreamFeatures(Tag currentTag)
throws XmlPullParserException, IOException {
this.streamFeatures = tagReader.readElement(currentTag);
@ -626,14 +612,19 @@ public class XmppConnection implements Runnable {
disconnect(true);
} else if (this.streamFeatures.hasChild("mechanisms")
&& shouldAuthenticate && usingEncryption) {
List<String> mechanisms = extractMechanisms(streamFeatures
final List<String> mechanisms = extractMechanisms(streamFeatures
.findChild("mechanisms"));
if (mechanisms.contains("PLAIN")) {
sendSaslAuthPlain();
} else if (mechanisms.contains("DIGEST-MD5")) {
sendSaslAuthDigestMd5();
}
} else if (this.streamFeatures.hasChild("sm", "urn:xmpp:sm:"
final Element auth = new Element("auth");
auth.setAttribute("xmlns", "urn:ietf:params:xml:ns:xmpp-sasl");
if (mechanisms.contains("DIGEST-MD5")) {
saslMechanism = new DigestMd5(tagWriter, account, mXmppConnectionService.getRNG());
} else if (mechanisms.contains("PLAIN")) {
saslMechanism = new Plain(tagWriter, account);
auth.setContent(((Plain)saslMechanism).getStartAuth());
}
auth.setAttribute("mechanism", saslMechanism.getMechanism());
tagWriter.writeElement(auth);
} else if (this.streamFeatures.hasChild("sm", "urn:xmpp:sm:"
+ smVersion)
&& streamId != null) {
ResumePacket resume = new ResumePacket(this.streamId,