From 3cc08ef765f65627d2260c4c69dfdacfa17a3fd6 Mon Sep 17 00:00:00 2001
From: Rhys Weatherley <rhys.weatherley@gmail.com>
Date: Fri, 8 Jul 2016 18:08:16 +1000
Subject: [PATCH] Spec rev30: Fixes for the new fallback patterns

---
 .../noise/protocol/HandshakeState.java              | 13 ++++++++++---
 .../com/southernstorm/noise/tests/VectorTests.java  | 12 ++++++++++--
 2 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/NoiseJava/src/com/southernstorm/noise/protocol/HandshakeState.java b/NoiseJava/src/com/southernstorm/noise/protocol/HandshakeState.java
index d7c332d..9753965 100644
--- a/NoiseJava/src/com/southernstorm/noise/protocol/HandshakeState.java
+++ b/NoiseJava/src/com/southernstorm/noise/protocol/HandshakeState.java
@@ -593,10 +593,17 @@ public class HandshakeState implements Destroyable {
 				throw new IllegalStateException("Responder cannot fall back from this state");
 		}
 		
-		// Format a new protocol name for the "XXfallback" variant
+		// Format a new protocol name for the fallback variant
 		// and recreate the SymmetricState object.
-		String name = symmetric.getProtocolName().replace("_IK_", "_XXfallback_");
-		String[] components = name.split("_");
+		String[] components = symmetric.getProtocolName().split("_");
+		components[1] = patternName;
+		StringBuilder builder = new StringBuilder();
+		builder.append(components[0]);
+		for (int index = 1; index < components.length; ++index) {
+			builder.append('_');
+			builder.append(components[index]);
+		}
+		String name = builder.toString();
 		SymmetricState newSymmetric = new SymmetricState(name, components[3], components[4]);
 		symmetric.destroy();
 		symmetric = newSymmetric;
diff --git a/NoiseJavaTests/src/com/southernstorm/noise/tests/VectorTests.java b/NoiseJavaTests/src/com/southernstorm/noise/tests/VectorTests.java
index 7bdd090..323d75c 100644
--- a/NoiseJavaTests/src/com/southernstorm/noise/tests/VectorTests.java
+++ b/NoiseJavaTests/src/com/southernstorm/noise/tests/VectorTests.java
@@ -75,6 +75,7 @@ public class VectorTests {
 		public String dh;
 		public String cipher;
 		public String hash;
+		public String fallback_pattern;
 		public byte[] init_prologue;
 		public byte[] init_ephemeral;
 		public byte[] init_static;
@@ -196,9 +197,14 @@ public class VectorTests {
 					// Success!
 				}
 				
+				// Look up the pattern to fall back to.
+				String pattern = vec.fallback_pattern;
+				if (pattern == null)
+					pattern = "XXfallback";
+
 				// Initiate fallback on both sides.
-				initiator.fallback();
-				responder.fallback();
+				initiator.fallback(pattern);
+				responder.fallback(pattern);
 				
 				// Restart the protocols.
 				initiator.start();
@@ -297,6 +303,8 @@ public class VectorTests {
 				vec.cipher = reader.nextString();
 			else if (name.equals("hash"))
 				vec.hash = reader.nextString();
+			else if (name.equals("fallback_pattern"))
+				vec.fallback_pattern = reader.nextString();
 			else if (name.equals("init_prologue"))
 				vec.init_prologue = DatatypeConverter.parseHexBinary(reader.nextString());
 			else if (name.equals("init_ephemeral"))