Introduce a NoiseKeyEncapsulationMechanism interface

Author: jchambers

src/main/java/com/eatthepath/noise/component/EncapsulatedKey.java

@@ -0,0 +1,4 @@
+package com.eatthepath.noise.component;
+
+public record EncapsulatedKey(byte[] sharedSecret, byte[] encapsulation) {
+}

src/main/java/com/eatthepath/noise/component/NoiseKeyEncapsulationMechanism.java

@@ -0,0 +1,26 @@
+package com.eatthepath.noise.component;
+
+import java.security.KeyPair;
+import java.security.PrivateKey;
+import java.security.PublicKey;
+
+public interface NoiseKeyEncapsulationMechanism {
+
+  static NoiseKeyEncapsulationMechanism getInstance(final String name) {
+    throw new IllegalArgumentException("Unrecognized key encapsulation method name: " + name);
+  }
+
+  String getName();
+
+  KeyPair generateKeyPair();
+
+  EncapsulatedKey encapsulate(PublicKey publicKey);
+
+  byte[] decapsulate(PrivateKey privateKey, byte[] encapsulation);
+
+  int getPublicKeyLength();
+
+  int getSharedSecretLength();
+
+  int getEncapsulationLength();
+}