implement SCRAM-SHA512

src/main/java/eu/siacs/conversations/crypto/sasl/Anonymous.java

@@ -7,6 +7,8 @@ import eu.siacs.conversations.xml.TagWriter;
 
 public class Anonymous extends SaslMechanism {
 
+    public static final String MECHANISM = "ANONYMOUS";
+
     public Anonymous(TagWriter tagWriter, Account account, SecureRandom rng) {
         super(tagWriter, account, rng);
     }
@@ -18,7 +20,7 @@ public class Anonymous extends SaslMechanism {
 
     @Override
     public String getMechanism() {
-		return "ANONYMOUS";
+        return MECHANISM;
     }
 
     @Override

src/main/java/eu/siacs/conversations/crypto/sasl/DigestMd5.java

@@ -12,6 +12,9 @@ import eu.siacs.conversations.utils.CryptoHelper;
 import eu.siacs.conversations.xml.TagWriter;
 
 public class DigestMd5 extends SaslMechanism {
+
+    public static final String MECHANISM = "DIGEST-MD5";
+
     public DigestMd5(final TagWriter tagWriter, final Account account, final SecureRandom rng) {
         super(tagWriter, account, rng);
     }
@@ -23,7 +26,7 @@ public class DigestMd5 extends SaslMechanism {
 
     @Override
     public String getMechanism() {
-		return "DIGEST-MD5";
+        return MECHANISM;
     }
 
     private State state = State.INITIAL;

src/main/java/eu/siacs/conversations/crypto/sasl/External.java

@@ -1,6 +1,7 @@
 package eu.siacs.conversations.crypto.sasl;
 
 import android.util.Base64;
+
 import java.security.SecureRandom;
 
 import eu.siacs.conversations.entities.Account;
@@ -8,6 +9,8 @@ import eu.siacs.conversations.xml.TagWriter;
 
 public class External extends SaslMechanism {
 
+    public static final String MECHANISM = "EXTERNAL";
+
     public External(TagWriter tagWriter, Account account, SecureRandom rng) {
         super(tagWriter, account, rng);
     }
@@ -19,7 +22,7 @@ public class External extends SaslMechanism {
 
     @Override
     public String getMechanism() {
-		return "EXTERNAL";
+        return MECHANISM;
     }
 
     @Override

src/main/java/eu/siacs/conversations/crypto/sasl/Plain.java

@@ -8,6 +8,9 @@ import eu.siacs.conversations.entities.Account;
 import eu.siacs.conversations.xml.TagWriter;
 
 public class Plain extends SaslMechanism {
+
+    public static final String MECHANISM = "PLAIN";
+
     public Plain(final TagWriter tagWriter, final Account account) {
         super(tagWriter, account, null);
     }
@@ -19,7 +22,7 @@ public class Plain extends SaslMechanism {
 
     @Override
     public String getMechanism() {
-		return "PLAIN";
+        return MECHANISM;
     }
 
     @Override

src/main/java/eu/siacs/conversations/crypto/sasl/SaslMechanism.java

@@ -52,14 +52,17 @@ public abstract class SaslMechanism {
      * The priority is used to pin the authentication mechanism. If authentication fails, it MAY be retried with another
      * mechanism of the same priority, but MUST NOT be tried with a mechanism of lower priority (to prevent downgrade
      * attacks).
+     *
      * @return An arbitrary int representing the priority
      */
     public abstract int getPriority();
 
     public abstract String getMechanism();
+
     public String getClientFirstMessage() {
         return "";
     }
+
     public String getResponse(final String challenge) throws AuthenticationException {
         return "";
     }

src/main/java/eu/siacs/conversations/crypto/sasl/ScramMechanism.java

@@ -1,7 +1,5 @@
 package eu.siacs.conversations.crypto.sasl;
 
-import android.annotation.TargetApi;
-import android.os.Build;
 import android.util.Base64;
 
 import com.google.common.base.Objects;
@@ -21,7 +19,6 @@ import eu.siacs.conversations.entities.Account;
 import eu.siacs.conversations.utils.CryptoHelper;
 import eu.siacs.conversations.xml.TagWriter;
 
-@TargetApi(Build.VERSION_CODES.HONEYCOMB_MR1)
 abstract class ScramMechanism extends SaslMechanism {
     // TODO: When channel binding (SCRAM-SHA1-PLUS) is supported in future, generalize this to indicate support and/or usage.
     private final static String GS2_HEADER = "n,,";

src/main/java/eu/siacs/conversations/crypto/sasl/ScramSha1.java

@@ -11,6 +11,8 @@ import eu.siacs.conversations.xml.TagWriter;
 
 public class ScramSha1 extends ScramMechanism {
 
+    public static final String MECHANISM = "SCRAM-SHA-1";
+
     @Override
     protected HMac getHMAC() {
         return new HMac(new SHA1Digest());
@@ -32,6 +34,6 @@ public class ScramSha1 extends ScramMechanism {
 
     @Override
     public String getMechanism() {
-		return "SCRAM-SHA-1";
+        return MECHANISM;
     }
 }

src/main/java/eu/siacs/conversations/crypto/sasl/ScramSha256.java

@@ -11,6 +11,8 @@ import eu.siacs.conversations.xml.TagWriter;
 
 public class ScramSha256 extends ScramMechanism {
 
+    public static final String MECHANISM = "SCRAM-SHA-256";
+
     @Override
     protected HMac getHMAC() {
         return new HMac(new SHA256Digest());
@@ -32,6 +34,6 @@ public class ScramSha256 extends ScramMechanism {
 
     @Override
     public String getMechanism() {
-		return "SCRAM-SHA-256";
+        return MECHANISM;
     }
 }

src/main/java/eu/siacs/conversations/crypto/sasl/ScramSha512.java

@@ -0,0 +1,39 @@
+package eu.siacs.conversations.crypto.sasl;
+
+import org.bouncycastle.crypto.Digest;
+import org.bouncycastle.crypto.digests.SHA512Digest;
+import org.bouncycastle.crypto.macs.HMac;
+
+import java.security.SecureRandom;
+
+import eu.siacs.conversations.entities.Account;
+import eu.siacs.conversations.xml.TagWriter;
+
+public class ScramSha512 extends ScramMechanism {
+
+    public static final String MECHANISM = "SCRAM-SHA-512";
+
+    @Override
+    protected HMac getHMAC() {
+        return new HMac(new SHA512Digest());
+    }
+
+    @Override
+    protected Digest getDigest() {
+        return new SHA512Digest();
+    }
+
+    public ScramSha512(final TagWriter tagWriter, final Account account, final SecureRandom rng) {
+        super(tagWriter, account, rng);
+    }
+
+    @Override
+    public int getPriority() {
+        return 30;
+    }
+
+    @Override
+    public String getMechanism() {
+        return MECHANISM;
+    }
+}

src/main/java/eu/siacs/conversations/xmpp/XmppConnection.java

@@ -64,6 +64,7 @@ import eu.siacs.conversations.crypto.sasl.Plain;
 import eu.siacs.conversations.crypto.sasl.SaslMechanism;
 import eu.siacs.conversations.crypto.sasl.ScramSha1;
 import eu.siacs.conversations.crypto.sasl.ScramSha256;
+import eu.siacs.conversations.crypto.sasl.ScramSha512;
 import eu.siacs.conversations.entities.Account;
 import eu.siacs.conversations.entities.Message;
 import eu.siacs.conversations.entities.ServiceDiscoveryResult;
@@ -870,20 +871,21 @@ public class XmppConnection implements Runnable {
     }
 
     private void authenticate() throws IOException {
-        final List<String> mechanisms = extractMechanisms(streamFeatures
+        final List<String> mechanisms = extractMechanisms(streamFeatures.findChild("mechanisms"));
-                .findChild("mechanisms"));
         final Element auth = new Element("auth", Namespace.SASL);
-        if (mechanisms.contains("EXTERNAL") && account.getPrivateKeyAlias() != null) {
+        if (mechanisms.contains(External.MECHANISM) && account.getPrivateKeyAlias() != null) {
             saslMechanism = new External(tagWriter, account, mXmppConnectionService.getRNG());
-        } else if (mechanisms.contains("SCRAM-SHA-256")) {
+        } else if (mechanisms.contains(ScramSha512.MECHANISM)) {
+            saslMechanism = new ScramSha512(tagWriter, account, mXmppConnectionService.getRNG());
+        } else if (mechanisms.contains(ScramSha256.MECHANISM)) {
             saslMechanism = new ScramSha256(tagWriter, account, mXmppConnectionService.getRNG());
-        } else if (mechanisms.contains("SCRAM-SHA-1")) {
+        } else if (mechanisms.contains(ScramSha1.MECHANISM)) {
             saslMechanism = new ScramSha1(tagWriter, account, mXmppConnectionService.getRNG());
-        } else if (mechanisms.contains("PLAIN") && !account.getJid().getDomain().toEscapedString().equals("nimbuzz.com")) {
+        } else if (mechanisms.contains(Plain.MECHANISM) && !account.getJid().getDomain().toEscapedString().equals("nimbuzz.com")) {
             saslMechanism = new Plain(tagWriter, account);
-        } else if (mechanisms.contains("DIGEST-MD5")) {
+        } else if (mechanisms.contains(DigestMd5.MECHANISM)) {
             saslMechanism = new DigestMd5(tagWriter, account, mXmppConnectionService.getRNG());
-        } else if (mechanisms.contains("ANONYMOUS")) {
+        } else if (mechanisms.contains(Anonymous.MECHANISM)) {
             saslMechanism = new Anonymous(tagWriter, account, mXmppConnectionService.getRNG());
         }
         if (saslMechanism != null) {