Provide an empty VaultTransitContext.

Provide VaultTransitContext.empty() to create an empty VaultTransitContext for encryption/decryption of binary plaintext without requiring to use VaultTransitContext builder.

Closes gh-54.

spring-vault-core/src/main/java/org/springframework/vault/support/VaultTransitContext.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016 the original author or authors.
+ * Copyright 2016-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -22,6 +22,12 @@ package org.springframework.vault.support;
  */
 public class VaultTransitContext {
 
+	/**
+	 * Empty (default) {@link VaultTransitContext} without a {@literal context} and
+	 * {@literal nonce}.
+	 */
+	private static final VaultTransitContext EMPTY = new VaultTransitContext(null, null);
+
 	private final byte[] context;
 
 	private final byte[] nonce;
@@ -38,6 +44,13 @@ public class VaultTransitContext {
 		return new VaultTransitRequestBuilder();
 	}
 
+	/**
+	 * @return an empty {@link VaultTransitContext}.
+	 */
+	public static VaultTransitContext empty() {
+		return EMPTY;
+	}
+
 	/**
 	 * @return the key derivation context.
 	 */
@@ -66,7 +79,7 @@ public class VaultTransitContext {
 
 		/**
 		 * Configure a key derivation context for the {@code transit} operation.
-		 * 
+		 *
 		 * @param context key derivation context, provided as a binary data. Must be
 		 * provided if derivation is enabled.
 		 * @return {@code this} {@link VaultTransitRequestBuilder}.
@@ -80,7 +93,7 @@ public class VaultTransitContext {
 		 * Configure the nonce value for a {@code transit} operation. Must be provided if
 		 * convergent encryption is enabled for this key and the key was generated with
 		 * Vault 0.6.1. Not required for keys created in 0.6.2+.
-		 * 
+		 *
 		 * @param nonce value must be exactly 96 bits (12 bytes) long and the user must
 		 * ensure that for any given context (and thus, any given encryption key) this
 		 * nonce value is never reused

spring-vault-core/src/test/java/org/springframework/vault/core/VaultTransitTemplateIntegrationTests.java

@@ -48,7 +48,7 @@ public class VaultTransitTemplateIntegrationTests extends IntegrationTestSupport
 	private VaultTransitOperations transitOperations;
 
 	@Before
-	public void before() throws Exception {
+	public void before() {
 		transitOperations = vaultOperations.opsForTransit();
 
 		if (!vaultOperations.opsForSys().getMounts().containsKey("transit/")) {
@@ -70,7 +70,7 @@ public class VaultTransitTemplateIntegrationTests extends IntegrationTestSupport
 	}
 
 	@Test
-	public void createKeyShouldCreateKey() throws Exception {
+	public void createKeyShouldCreateKey() {
 
 		transitOperations.createKey("mykey");
 
@@ -86,7 +86,7 @@ public class VaultTransitTemplateIntegrationTests extends IntegrationTestSupport
 	}
 
 	@Test
-	public void createKeyShouldCreateKeyWithOptions() throws Exception {
+	public void createKeyShouldCreateKeyWithOptions() {
 
 		VaultTransitKeyCreationRequest request = VaultTransitKeyCreationRequest.builder() //
 				.convergentEncryption(true) //
@@ -105,14 +105,14 @@ public class VaultTransitTemplateIntegrationTests extends IntegrationTestSupport
 	}
 
 	@Test
-	public void getKeyShouldReturnNullIfKeyNotExists() throws Exception {
+	public void getKeyShouldReturnNullIfKeyNotExists() {
 
 		VaultTransitKey key = transitOperations.getKey("hello-world");
 		assertThat(key).isNull();
 	}
 
 	@Test
-	public void deleteKeyShouldFailIfKeyNotExists() throws Exception {
+	public void deleteKeyShouldFailIfKeyNotExists() {
 
 		try {
 			transitOperations.deleteKey("hello-world");
@@ -124,7 +124,7 @@ public class VaultTransitTemplateIntegrationTests extends IntegrationTestSupport
 	}
 
 	@Test
-	public void deleteKeyShouldDeleteKey() throws Exception {
+	public void deleteKeyShouldDeleteKey() {
 
 		transitOperations.createKey("mykey");
 		transitOperations.configureKey("mykey", VaultTransitKeyConfiguration.builder()
@@ -135,7 +135,7 @@ public class VaultTransitTemplateIntegrationTests extends IntegrationTestSupport
 	}
 
 	@Test
-	public void encryptShouldCreateCiphertext() throws Exception {
+	public void encryptShouldCreateCiphertext() {
 
 		transitOperations.createKey("mykey");
 
@@ -144,7 +144,7 @@ public class VaultTransitTemplateIntegrationTests extends IntegrationTestSupport
 	}
 
 	@Test
-	public void encryptShouldCreateCiphertextWithNonceAndContext() throws Exception {
+	public void encryptShouldCreateCiphertextWithNonceAndContext() {
 
 		transitOperations.createKey("mykey", VaultTransitKeyCreationRequest.builder()
 				.convergentEncryption(true).derived(true).build());
@@ -160,7 +160,7 @@ public class VaultTransitTemplateIntegrationTests extends IntegrationTestSupport
 	}
 
 	@Test
-	public void decryptShouldCreatePlaintext() throws Exception {
+	public void decryptShouldCreatePlaintext() {
 
 		transitOperations.createKey("mykey");
 
@@ -171,7 +171,7 @@ public class VaultTransitTemplateIntegrationTests extends IntegrationTestSupport
 	}
 
 	@Test
-	public void decryptShouldCreatePlaintextWithNonceAndContext() throws Exception {
+	public void decryptShouldCreatePlaintextWithNonceAndContext() {
 
 		transitOperations.createKey("mykey", VaultTransitKeyCreationRequest.builder()
 				.convergentEncryption(true).derived(true).build());
@@ -189,7 +189,7 @@ public class VaultTransitTemplateIntegrationTests extends IntegrationTestSupport
 	}
 
 	@Test
-	public void encryptAndRewrapShouldCreateCiphertext() throws Exception {
+	public void encryptAndRewrapShouldCreateCiphertext() {
 
 		transitOperations.createKey("mykey");
 
@@ -202,8 +202,23 @@ public class VaultTransitTemplateIntegrationTests extends IntegrationTestSupport
 	}
 
 	@Test
-	public void encryptAndRewrapShouldCreateCiphertextWithNonceAndContext()
-			throws Exception {
+	public void shouldEncryptBinaryPlaintext() {
+
+		transitOperations.createKey("mykey");
+
+		byte[] plaintext = new byte[] { 1, 2, 3, 4, 5 };
+
+		String ciphertext = transitOperations.encrypt("mykey", plaintext,
+				VaultTransitContext.empty());
+
+		byte[] decrypted = transitOperations.decrypt("mykey", ciphertext,
+				VaultTransitContext.empty());
+
+		assertThat(decrypted).isEqualTo(plaintext);
+	}
+
+	@Test
+	public void encryptAndRewrapShouldCreateCiphertextWithNonceAndContext() {
 
 		transitOperations.createKey("mykey", VaultTransitKeyCreationRequest.builder()
 				.convergentEncryption(true).derived(true).build());