diff --git a/src/eu/siacs/conversations/utils/CryptoHelper.java b/src/eu/siacs/conversations/utils/CryptoHelper.java
index 74f942bf2..08a65992e 100644
--- a/src/eu/siacs/conversations/utils/CryptoHelper.java
+++ b/src/eu/siacs/conversations/utils/CryptoHelper.java
@@ -1,37 +1,105 @@
 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 java.util.Random;
 
+import eu.siacs.conversations.entities.Account;
+
 import android.util.Base64;
+import android.util.Log;
 
 public class CryptoHelper {
 	final protected static char[] hexArray = "0123456789ABCDEF".toCharArray();
 	final protected static char[] vowels = "aeiou".toCharArray();
-	final protected static char[] consonants ="bcdfghjklmnpqrstvwxyz".toCharArray();
+	final protected static char[] consonants = "bcdfghjklmnpqrstvwxyz"
+			.toCharArray();
+
 	public static String bytesToHex(byte[] bytes) {
-	    char[] hexChars = new char[bytes.length * 2];
-	    for ( int j = 0; j < bytes.length; j++ ) {
-	        int v = bytes[j] & 0xFF;
-	        hexChars[j * 2] = hexArray[v >>> 4];
-	        hexChars[j * 2 + 1] = hexArray[v & 0x0F];
-	    }
-	    return new String(hexChars);
+		char[] hexChars = new char[bytes.length * 2];
+		for (int j = 0; j < bytes.length; j++) {
+			int v = bytes[j] & 0xFF;
+			hexChars[j * 2] = hexArray[v >>> 4];
+			hexChars[j * 2 + 1] = hexArray[v & 0x0F];
+		}
+		return new String(hexChars).toLowerCase();
 	}
+
 	public static String saslPlain(String username, String password) {
-		String sasl = '\u0000'+username + '\u0000' + password;
-		return Base64.encodeToString(sasl.getBytes(Charset.defaultCharset()),Base64.NO_WRAP);
+		String sasl = '\u0000' + username + '\u0000' + password;
+		return Base64.encodeToString(sasl.getBytes(Charset.defaultCharset()),
+				Base64.NO_WRAP);
 	}
+
+	private 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) {
+		try {
+			Random random = new SecureRandom();
+			Log.d("xmppService",
+					"challenge="
+							+ new String(Base64.decode(challenge,
+									Base64.DEFAULT)));
+			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);
+			Log.d("xmppService", "conce=" + cNonce);
+			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;
+			Log.d("xmppService", "kd=" + kd);
+			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,authzid=\"" + account.getJid() + "\"";
+			Log.d("xmppService", "saslString=" + saslString);
+			return Base64.encodeToString(
+					saslString.getBytes(Charset.defaultCharset()),
+					Base64.NO_WRAP);
+		} catch (NoSuchAlgorithmException e) {
+			return null;
+		}
+	}
+
 	public static String randomMucName() {
 		Random random = new SecureRandom();
-		return randomWord(3,random)+"."+randomWord(7,random);
+		return randomWord(3, random) + "." + randomWord(7, random);
 	}
-	
-	protected static String randomWord(int lenght,Random random) {
+
+	protected static String randomWord(int lenght, Random random) {
 		StringBuilder builder = new StringBuilder(lenght);
-		for(int i = 0; i < lenght; ++i) {
+		for (int i = 0; i < lenght; ++i) {
 			if (i % 2 == 0) {
 				builder.append(consonants[random.nextInt(consonants.length)]);
 			} else {
diff --git a/src/eu/siacs/conversations/xmpp/XmppConnection.java b/src/eu/siacs/conversations/xmpp/XmppConnection.java
index 36bd4be22..4baf5fae0 100644
--- a/src/eu/siacs/conversations/xmpp/XmppConnection.java
+++ b/src/eu/siacs/conversations/xmpp/XmppConnection.java
@@ -210,11 +210,16 @@ public class XmppConnection implements Runnable {
 				processStream(tagReader.readTag());
 				break;
 			} else if (nextTag.isStart("failure")) {
-				tagReader.readElement(nextTag);
+				Element failure = tagReader.readElement(nextTag);
+				Log.d(LOGTAG,"login failure"+failure);
 				changeStatus(Account.STATUS_UNAUTHORIZED);
 			} else if (nextTag.isStart("challenge")) {
 				String challange = tagReader.readElement(nextTag).getContent();
-				Log.d(LOGTAG,"a challange arrived! "+challange);
+				Element response = new Element("response");
+				response.setAttribute("xmlns", "urn:ietf:params:xml:ns:xmpp-sasl");
+				response.setContent(CryptoHelper.saslDigestMd5(account, challange));
+				Log.d(LOGTAG,response.toString());
+				tagWriter.writeElement(response);
 			} else if (nextTag.isStart("enabled")) {
 				this.stanzasSent = 0;
 				Element enabled = tagReader.readElement(nextTag);