1 files changed, 27 insertions, 0 deletions
diff --git a/src/main/java/eu/siacs/conversations/crypto/sasl/SaslMechanism.java b/src/main/java/eu/siacs/conversations/crypto/sasl/SaslMechanism.java
index 38a03c18..7dd5e99c 100644
--- a/src/main/java/eu/siacs/conversations/crypto/sasl/SaslMechanism.java
+++ b/src/main/java/eu/siacs/conversations/crypto/sasl/SaslMechanism.java
@@ -11,6 +11,33 @@ public abstract class SaslMechanism {
 	final protected Account account;
 	final protected SecureRandom rng;
 
+	protected static enum State {
+		INITIAL,
+		AUTH_TEXT_SENT,
+		RESPONSE_SENT,
+		VALID_SERVER_RESPONSE,
+	}
+
+	public static class AuthenticationException extends Exception {
+		public AuthenticationException(final String message) {
+			super(message);
+		}
+
+		public AuthenticationException(final Exception inner) {
+			super(inner);
+		}
+	}
+
+	public static class InvalidStateException extends AuthenticationException {
+		public InvalidStateException(final String message) {
+			super(message);
+		}
+
+		public InvalidStateException(final State state) {
+			this("Invalid state: " + state.toString());
+		}
+	}
+
 	public SaslMechanism(final TagWriter tagWriter, final Account account, final SecureRandom rng) {
 		this.tagWriter = tagWriter;
 		this.account = account;