Adding AES Walk Encryption support in http://www.jets3t.org/ mode

See previous attempt: https://git.eclipse.org/r/#/c/16674/

Here we preserve as much of JetS3t mode as possible
while allowing to use new Java 8+ PBE algorithms
such as PBEWithHmacSHA512AndAES_256

Summary of changes:
* change pom.xml to control long tests
* add WalkEncryptionTest.launch to run long tests
* add AmazonS3.Keys to to normalize use of constants
* change WalkEncryption to support AES in JetS3t mode
* add WalkEncryptionTest to test remote encryption pipeline
* add support for CI configuration for live Amazon S3 testing
* add log4j based logging for tests in both Eclipse and Maven build

To test locally, check out the review branch, then:
* create amazon test configuration file
* located your home dir: ${user.home}
* named jgit-s3-config.properties
* file format follows AmazonS3 connection settings file:
	accesskey = your-amazon-access-key
	secretkey = your-amazon-secret-key
	test.bucket = your-bucket-for-testing
* finally:
* run in Eclipse: WalkEncryptionTest.launch
* or
* run in Shell: mvn test --define test=WalkEncryptionTest

Change-Id: I6f455fd9fb4eac261ca73d0bec6a4e7dae9f2e91
Signed-off-by: Andrei Pozolotin <andrei.pozolotin@gmail.com>

9 files changed, 1230 insertions, 0 deletions

diff --git a/org.eclipse.jgit.test/build.properties b/org.eclipse.jgit.test/build.properties
index afc4855d67..786046c58a 100644
--- a/org.eclipse.jgit.test/build.properties
+++ b/org.eclipse.jgit.test/build.properties
@@ -4,3 +4,4 @@ source.. = tst/,\
 bin.includes = META-INF/,\
                .,\
                plugin.properties
+additional.bundles = org.apache.log4j
diff --git a/org.eclipse.jgit.test/org.eclipse.jgit.test-WalkEncryptionTest-Proxy.launch b/org.eclipse.jgit.test/org.eclipse.jgit.test-WalkEncryptionTest-Proxy.launch
new file mode 100644
index 0000000000..fe3a013720
--- /dev/null
+++ b/org.eclipse.jgit.test/org.eclipse.jgit.test-WalkEncryptionTest-Proxy.launch
@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<launchConfiguration type="org.eclipse.m2e.Maven2LaunchConfigurationType">
+<booleanAttribute key="M2_DEBUG_OUTPUT" value="false"/>
+<stringAttribute key="M2_GOALS" value="test --define test=WalkEncryptionTest --define http_proxy=http://proxy:3128"/>
+<booleanAttribute key="M2_NON_RECURSIVE" value="false"/>
+<booleanAttribute key="M2_OFFLINE" value="false"/>
+<stringAttribute key="M2_PROFILES" value=""/>
+<listAttribute key="M2_PROPERTIES"/>
+<stringAttribute key="M2_RUNTIME" value="EMBEDDED"/>
+<booleanAttribute key="M2_SKIP_TESTS" value="false"/>
+<intAttribute key="M2_THREADS" value="1"/>
+<booleanAttribute key="M2_UPDATE_SNAPSHOTS" value="false"/>
+<stringAttribute key="M2_USER_SETTINGS" value=""/>
+<booleanAttribute key="M2_WORKSPACE_RESOLUTION" value="false"/>
+<listAttribute key="org.eclipse.debug.ui.favoriteGroups">
+<listEntry value="org.eclipse.debug.ui.launchGroup.run"/>
+</listAttribute>
+<stringAttribute key="org.eclipse.jdt.launching.JRE_CONTAINER" value="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/java-8-oracle"/>
+<stringAttribute key="org.eclipse.jdt.launching.WORKING_DIRECTORY" value="${workspace_loc:/org.eclipse.jgit.test}"/>
+</launchConfiguration>
diff --git a/org.eclipse.jgit.test/org.eclipse.jgit.test-WalkEncryptionTest.launch b/org.eclipse.jgit.test/org.eclipse.jgit.test-WalkEncryptionTest.launch
new file mode 100644
index 0000000000..3b4a5a24e1
--- /dev/null
+++ b/org.eclipse.jgit.test/org.eclipse.jgit.test-WalkEncryptionTest.launch
@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<launchConfiguration type="org.eclipse.m2e.Maven2LaunchConfigurationType">
+<booleanAttribute key="M2_DEBUG_OUTPUT" value="false"/>
+<stringAttribute key="M2_GOALS" value="test --define test=WalkEncryptionTest --activate-profiles test.long"/>
+<booleanAttribute key="M2_NON_RECURSIVE" value="false"/>
+<booleanAttribute key="M2_OFFLINE" value="false"/>
+<stringAttribute key="M2_PROFILES" value=""/>
+<listAttribute key="M2_PROPERTIES"/>
+<stringAttribute key="M2_RUNTIME" value="EMBEDDED"/>
+<booleanAttribute key="M2_SKIP_TESTS" value="false"/>
+<intAttribute key="M2_THREADS" value="1"/>
+<booleanAttribute key="M2_UPDATE_SNAPSHOTS" value="false"/>
+<stringAttribute key="M2_USER_SETTINGS" value=""/>
+<booleanAttribute key="M2_WORKSPACE_RESOLUTION" value="false"/>
+<listAttribute key="org.eclipse.debug.ui.favoriteGroups">
+<listEntry value="org.eclipse.debug.ui.launchGroup.run"/>
+</listAttribute>
+<stringAttribute key="org.eclipse.jdt.launching.JRE_CONTAINER" value="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/java-8-oracle"/>
+<stringAttribute key="org.eclipse.jdt.launching.WORKING_DIRECTORY" value="${workspace_loc:/org.eclipse.jgit.test}"/>
+</launchConfiguration>
diff --git a/org.eclipse.jgit.test/pom.xml b/org.eclipse.jgit.test/pom.xml
index 51ac8463cc..539caff149 100644
--- a/org.eclipse.jgit.test/pom.xml
+++ b/org.eclipse.jgit.test/pom.xml
@@ -69,6 +69,16 @@
       <scope>test</scope>
     </dependency>
 
+    <!-- Optional security provider for encryption tests. -->
+    <!-- See https://dev.eclipse.org/ipzilla/show_bug.cgi?id=9554 -->
+    <!-- See https://bugs.eclipse.org/bugs/show_bug.cgi?id=467064 -->
+    <dependency>
+      <groupId>org.bouncycastle</groupId>
+      <artifactId>bcprov-jdk15on</artifactId>
+      <version>1.52</version>
+      <scope>test</scope>
+     </dependency>
+
     <dependency>
       <groupId>org.hamcrest</groupId>
       <artifactId>hamcrest-library</artifactId>
@@ -101,6 +111,24 @@
     </dependency>
   </dependencies>
 
+  <profiles>
+    <!-- Profile provides a property which enables long running tests. -->
+    <profile>
+      <id>test.long</id>
+      <build>
+        <plugins>
+          <plugin>
+            <groupId>org.apache.maven.plugins</groupId>
+            <artifactId>maven-surefire-plugin</artifactId>
+            <configuration>
+              <argLine>-Djgit.test.long=true</argLine>
+            </configuration>
+          </plugin>
+        </plugins>
+      </build>
+    </profile>
+  </profiles>
+
   <build>
     <sourceDirectory>src/</sourceDirectory>
     <testSourceDirectory>tst/</testSourceDirectory>
diff --git a/org.eclipse.jgit.test/tst-rsrc/jgit-s3-config.disabled.properties b/org.eclipse.jgit.test/tst-rsrc/jgit-s3-config.disabled.properties
new file mode 100644
index 0000000000..d540977e94
--- /dev/null
+++ b/org.eclipse.jgit.test/tst-rsrc/jgit-s3-config.disabled.properties
@@ -0,0 +1,48 @@
+#
+# See WalkEncryptionTest.java
+#
+# This file is a template for test configuration file used by WalkEncryptionTest.
+# To be active, this file must have the following hard coded name: jgit-s3-config.properties
+# To be active, this file must be discovered by WalkEncryptionTest from one of these locations:
+# * ${user.home}/jgit-s3-config.properties
+# * ${user.dir}/jgit-s3-config.properties
+# * ${user.dir}/tst-rsrc/jgit-s3-config.properties
+# When this file is missing, tests in WalkEncryptionTest will not run, only report a warning.
+#
+
+#
+# WalkEncryptionTest requires amazon s3 test bucket setup.
+#
+# Test bucket setup instructions:
+#
+# Create IAM user:
+# http://docs.aws.amazon.com/IAM/latest/UserGuide/id_users_create.html
+# * user name: jgit.eclipse.org
+#
+# Configure IAM user S3 bucket access
+# http://docs.aws.amazon.com/AmazonS3/latest/dev/example-policies-s3.html
+# * attach S3 user policy to user account: jgit-s3-config.policy.user.json
+#
+# Create S3 bucket:
+# http://docs.aws.amazon.com/AmazonS3/latest/gsg/CreatingABucket.html
+# * bucket name: jgit.eclipse.org
+#
+# Configure S3 bucket source address/mask access:
+# http://docs.aws.amazon.com/AmazonS3/latest/dev/example-bucket-policies.html
+# * attach bucket policy to the test bucket: jgit-s3-config.policy.bucket.json
+# * verify that any required source address/mask is included in the bucket policy:
+# * see https://wiki.eclipse.org/Hudson
+# * see http://www.tcpiputils.com/browse/ip-address/198.41.30.200
+# * proxy.eclipse.org	198.41.30.0/24
+# * Andrei Pozolotin	67.175.188.187/32
+#
+# Configure bucket 1 day expiration in object life cycle management:
+# * https://docs.aws.amazon.com/AmazonS3/latest/dev/manage-lifecycle-using-console.html
+#
+
+# Test bucket name
+test.bucket=jgit.eclipse.org
+
+# IAM credentials for user jgit.eclipse.org
+accesskey=AKIAIYWXB4ETREBRMZDQ
+secretkey=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
diff --git a/org.eclipse.jgit.test/tst-rsrc/jgit-s3-config.policy.bucket.json b/org.eclipse.jgit.test/tst-rsrc/jgit-s3-config.policy.bucket.json
new file mode 100644
index 0000000000..3020b09a00
--- /dev/null
+++ b/org.eclipse.jgit.test/tst-rsrc/jgit-s3-config.policy.bucket.json
@@ -0,0 +1,20 @@
+{
+    "Version": "2012-10-17",
+    "Statement": [
+        {
+            "Sid": "DenyAllButKnownSourceAddressWithMask",
+            "Effect": "Deny",
+            "Principal": "*",
+            "Action": "s3:*",
+            "Resource": "arn:aws:s3:::jgit.eclipse.org/*",
+            "Condition": {
+                "NotIpAddress": {
+                    "aws:SourceIp": [
+                        "198.41.30.0/24",
+                        "67.175.188.187/32"
+                    ]
+                }
+            }
+        }
+    ]
+}
diff --git a/org.eclipse.jgit.test/tst-rsrc/jgit-s3-config.policy.user.json b/org.eclipse.jgit.test/tst-rsrc/jgit-s3-config.policy.user.json
new file mode 100644
index 0000000000..830d0888c0
--- /dev/null
+++ b/org.eclipse.jgit.test/tst-rsrc/jgit-s3-config.policy.user.json
@@ -0,0 +1,24 @@
+{
+    "Version": "2012-10-17",
+    "Statement": [
+        {
+            "Sid": "BucketList",
+            "Effect": "Allow",
+            "Action": "s3:ListAllMyBuckets",
+            "Resource": [
+                "arn:aws:s3:::jgit.eclipse.org"
+            ]
+        },
+        {
+            "Sid": "BucketFullControl",
+            "Effect": "Allow",
+            "Action": [
+                "s3:*"
+            ],
+            "Resource": [
+                "arn:aws:s3:::jgit.eclipse.org",
+                "arn:aws:s3:::jgit.eclipse.org/*"
+            ]
+        }
+    ]
+}
diff --git a/org.eclipse.jgit.test/tst-rsrc/log4j.properties b/org.eclipse.jgit.test/tst-rsrc/log4j.properties
new file mode 100644
index 0000000000..14620ffae4
--- /dev/null
+++ b/org.eclipse.jgit.test/tst-rsrc/log4j.properties
@@ -0,0 +1,9 @@
+
+# Root logger option
+log4j.rootLogger=INFO, stdout
+
+# Direct log messages to stdout
+log4j.appender.stdout=org.apache.log4j.ConsoleAppender
+log4j.appender.stdout.Target=System.out
+log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
+log4j.appender.stdout.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n
diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/WalkEncryptionTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/WalkEncryptionTest.java
new file mode 100644
index 0000000000..f2701cb41f
--- /dev/null
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/WalkEncryptionTest.java
@@ -0,0 +1,1060 @@
+/*
+ * Copyright (C) 2015, Andrei Pozolotin.
+ * and other copyright owners as documented in the project's IP log.
+ *
+ * This program and the accompanying materials are made available
+ * under the terms of the Eclipse Distribution License v1.0 which
+ * accompanies this distribution, is reproduced below, and is
+ * available at http://www.eclipse.org/org/documents/edl-v10.php
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above
+ *   copyright notice, this list of conditions and the following
+ *   disclaimer in the documentation and/or other materials provided
+ *   with the distribution.
+ *
+ * - Neither the name of the Eclipse Foundation, Inc. nor the
+ *   names of its contributors may be used to endorse or promote
+ *   products derived from this software without specific prior
+ *   written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
+ * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package org.eclipse.jgit.transport;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assume.assumeTrue;
+
+import java.io.BufferedReader;
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.OutputStream;
+import java.io.PrintWriter;
+import java.net.URL;
+import java.nio.charset.Charset;
+import java.nio.file.Files;
+import java.security.GeneralSecurityException;
+import java.security.Provider;
+import java.security.Security;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+import java.util.Properties;
+import java.util.Set;
+import java.util.TreeSet;
+import java.util.UUID;
+
+import javax.crypto.SecretKeyFactory;
+
+import org.apache.log4j.Logger;
+import org.eclipse.jgit.api.Git;
+import org.eclipse.jgit.lib.StoredConfig;
+import org.eclipse.jgit.test.resources.SampleDataRepositoryTestCase;
+import org.eclipse.jgit.util.FileUtils;
+import org.junit.After;
+import org.junit.AfterClass;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.FixMethodOrder;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.MethodSorters;
+import org.junit.runners.Parameterized;
+import org.junit.runners.Parameterized.Parameters;
+import org.junit.runners.Suite;
+
+import static org.eclipse.jgit.transport.WalkEncryptionTest.Util.*;
+
+/**
+ * Amazon S3 encryption pipeline test.
+ *
+ * See {@link AmazonS3} {@link WalkEncryption}
+ *
+ * Note: CI server must provide amazon credentials (access key, secret key,
+ * bucket name) via one of methods available in {@link Names}.
+ *
+ * Note: long running tests are activated by Maven profile "test.long". There is
+ * also a separate Eclipse m2e launcher for that. See 'pom.xml' and
+ * 'WalkEncryptionTest.launch'.
+ */
+@RunWith(Suite.class)
+@Suite.SuiteClasses({ //
+		WalkEncryptionTest.MinimalSet.class, //
+		WalkEncryptionTest.TestablePBE.class, //
+})
+public class WalkEncryptionTest {
+
+	/**
+	 * Logger setup: ${project_loc}/tst-rsrc/log4j.properties
+	 */
+	static final Logger logger = Logger.getLogger(WalkEncryptionTest.class);
+
+	/**
+	 * Property names used in test session.
+	 */
+	interface Names {
+
+		// Names of discovered test properties.
+
+		String TEST_BUCKET = "test.bucket";
+
+		// Names of test environment variables for CI.
+
+		String ENV_ACCESS_KEY = "JGIT_S3_ACCESS_KEY";
+
+		String ENV_SECRET_KEY = "JGIT_S3_SECRET_KEY";
+
+		String ENV_BUCKET_NAME = "JGIT_S3_BUCKET_NAME";
+
+		// Name of test environment variable file path for CI.
+
+		String ENV_CONFIG_FILE = "JGIT_S3_CONFIG_FILE";
+
+		// Names of test system properties for CI.
+
+		String SYS_ACCESS_KEY = "jgit.s3.access.key";
+
+		String SYS_SECRET_KEY = "jgit.s3.secret.key";
+
+		String SYS_BUCKET_NAME = "jgit.s3.bucket.name";
+
+		// Name of test system property file path for CI.
+		String SYS_CONFIG_FILE = "jgit.s3.config.file";
+
+		// Hard coded name of test properties file for CI.
+		// File format follows AmazonS3.Keys:
+		// #
+		// # Required entries:
+		// #
+		// accesskey = your-amazon-access-key # default AmazonS3.Keys
+		// secretkey = your-amazon-secret-key # default AmazonS3.Keys
+		// test.bucket = your-bucket-for-testing # custom name, for this test
+		String CONFIG_FILE = "jgit-s3-config.properties";
+
+		// Test properties file in [user home] of CI.
+		String HOME_CONFIG_FILE = System.getProperty("user.home")
+				+ File.separator + CONFIG_FILE;
+
+		// Test properties file in [project work directory] of CI.
+		String WORK_CONFIG_FILE = System.getProperty("user.dir")
+				+ File.separator + CONFIG_FILE;
+
+		// Test properties file in [project test source directory] of CI.
+		String TEST_CONFIG_FILE = System.getProperty("user.dir")
+				+ File.separator + "tst-rsrc" + File.separator + CONFIG_FILE;
+
+	}
+
+	/**
+	 * Find test properties from various sources in order of priority.
+	 */
+	static class Props implements WalkEncryptionTest.Names, AmazonS3.Keys {
+
+		static boolean haveEnvVar(String name) {
+			return System.getenv(name) != null;
+		}
+
+		static boolean haveEnvVarFile(String name) {
+			return haveEnvVar(name) && new File(name).exists();
+		}
+
+		static boolean haveSysProp(String name) {
+			return System.getProperty(name) != null;
+		}
+
+		static boolean haveSysPropFile(String name) {
+			return haveSysProp(name) && new File(name).exists();
+		}
+
+		static void loadEnvVar(String source, String target, Properties props) {
+			props.put(target, System.getenv(source));
+		}
+
+		static void loadSysProp(String source, String target,
+				Properties props) {
+			props.put(target, System.getProperty(source));
+		}
+
+		static boolean haveProp(String name, Properties props) {
+			return props.containsKey(name);
+		}
+
+		static boolean checkTestProps(Properties props) {
+			return haveProp(ACCESS_KEY, props) && haveProp(SECRET_KEY, props)
+					&& haveProp(TEST_BUCKET, props);
+		}
+
+		static Properties fromEnvVars() {
+			if (haveEnvVar(ENV_ACCESS_KEY) && haveEnvVar(ENV_SECRET_KEY)
+					&& haveEnvVar(ENV_BUCKET_NAME)) {
+				Properties props = new Properties();
+				loadEnvVar(ENV_ACCESS_KEY, ACCESS_KEY, props);
+				loadEnvVar(ENV_SECRET_KEY, SECRET_KEY, props);
+				loadEnvVar(ENV_BUCKET_NAME, TEST_BUCKET, props);
+				return props;
+			} else {
+				return null;
+			}
+		}
+
+		static Properties fromEnvFile() throws Exception {
+			if (haveEnvVarFile(ENV_CONFIG_FILE)) {
+				Properties props = new Properties();
+				props.load(new FileInputStream(ENV_CONFIG_FILE));
+				if (checkTestProps(props)) {
+					return props;
+				} else {
+					throw new Error("Environment config file is incomplete.");
+				}
+			} else {
+				return null;
+			}
+		}
+
+		static Properties fromSysProps() {
+			if (haveSysProp(SYS_ACCESS_KEY) && haveSysProp(SYS_SECRET_KEY)
+					&& haveSysProp(SYS_BUCKET_NAME)) {
+				Properties props = new Properties();
+				loadSysProp(SYS_ACCESS_KEY, ACCESS_KEY, props);
+				loadSysProp(SYS_SECRET_KEY, SECRET_KEY, props);
+				loadSysProp(SYS_BUCKET_NAME, TEST_BUCKET, props);
+				return props;
+			} else {
+				return null;
+			}
+		}
+
+		static Properties fromSysFile() throws Exception {
+			if (haveSysPropFile(SYS_CONFIG_FILE)) {
+				Properties props = new Properties();
+				props.load(new FileInputStream(SYS_CONFIG_FILE));
+				if (checkTestProps(props)) {
+					return props;
+				} else {
+					throw new Error("System props config file is incomplete.");
+				}
+			} else {
+				return null;
+			}
+		}
+
+		static Properties fromConfigFile(String path) throws Exception {
+			File file = new File(path);
+			if (file.exists()) {
+				Properties props = new Properties();
+				props.load(new FileInputStream(file));
+				if (checkTestProps(props)) {
+					return props;
+				} else {
+					throw new Error("Props config file is incomplete: " + path);
+				}
+			} else {
+				return null;
+			}
+		}
+
+		/**
+		 * Find test properties from various sources in order of priority.
+		 *
+		 * @return result
+		 * @throws Exception
+		 */
+		static Properties discover() throws Exception {
+			Properties props;
+			if ((props = fromEnvVars()) != null) {
+				logger.debug(
+						"Using test properties from environment variables.");
+				return props;
+			}
+			if ((props = fromEnvFile()) != null) {
+				logger.debug(
+						"Using test properties from environment variable config file.");
+				return props;
+			}
+			if ((props = fromSysProps()) != null) {
+				logger.debug("Using test properties from system properties.");
+				return props;
+			}
+			if ((props = fromSysFile()) != null) {
+				logger.debug(
+						"Using test properties from system property config file.");
+				return props;
+			}
+			if ((props = fromConfigFile(HOME_CONFIG_FILE)) != null) {
+				logger.debug(
+						"Using test properties from hard coded ${user.home} file.");
+				return props;
+			}
+			if ((props = fromConfigFile(WORK_CONFIG_FILE)) != null) {
+				logger.debug(
+						"Using test properties from hard coded ${user.dir} file.");
+				return props;
+			}
+			if ((props = fromConfigFile(TEST_CONFIG_FILE)) != null) {
+				logger.debug(
+						"Using test properties from hard coded ${project.source} file.");
+				return props;
+			}
+			throw new Error("Can not load test properties form any source.");
+		}
+
+	}
+
+	/**
+	 * Collection of test utility methods.
+	 */
+	static class Util {
+
+		static final Charset UTF_8 = Charset.forName("UTF-8");
+
+		/**
+		 * Read UTF-8 encoded text file into string.
+		 *
+		 * @param file
+		 * @return result
+		 * @throws Exception
+		 */
+		static String textRead(File file) throws Exception {
+			return new String(Files.readAllBytes(file.toPath()), UTF_8);
+		}
+
+		/**
+		 * Write string into UTF-8 encoded file.
+		 *
+		 * @param file
+		 * @param text
+		 * @throws Exception
+		 */
+		static void textWrite(File file, String text) throws Exception {
+			Files.write(file.toPath(), text.getBytes(UTF_8));
+		}
+
+		static void verifyFileContent(File fileOne, File fileTwo)
+				throws Exception {
+			assertTrue(fileOne.length() > 0);
+			assertTrue(fileTwo.length() > 0);
+			String textOne = textRead(fileOne);
+			String textTwo = textRead(fileTwo);
+			assertEquals(textOne, textTwo);
+		}
+
+		/**
+		 * Create local folder.
+		 *
+		 * @param folder
+		 * @throws Exception
+		 */
+		static void folderCreate(String folder) throws Exception {
+			File path = new File(folder);
+			assertTrue(path.mkdirs());
+		}
+
+		/**
+		 * Delete local folder.
+		 *
+		 * @param folder
+		 * @throws Exception
+		 */
+		static void folderDelete(String folder) throws Exception {
+			File path = new File(folder);
+			FileUtils.delete(path,
+					FileUtils.RECURSIVE | FileUtils.SKIP_MISSING);
+		}
+
+		/**
+		 * Discover public address of CI server.
+		 *
+		 * @return result
+		 * @throws Exception
+		 */
+		static String publicAddress() throws Exception {
+			String service = "http://checkip.amazonaws.com";
+			URL url = new URL(service);
+			BufferedReader reader = new BufferedReader(
+					new InputStreamReader(url.openStream()));
+			try {
+				return reader.readLine();
+			} finally {
+				reader.close();
+			}
+		}
+
+		/**
+		 * Discover Password-Based Encryption (PBE) engines providing both
+		 * [SecretKeyFactory] and [AlgorithmParameters].
+		 *
+		 * @return result
+		 */
+		// https://www.bouncycastle.org/specifications.html
+		// https://docs.oracle.com/javase/8/docs/technotes/guides/security/SunProviders.html
+		static List<String> cryptoCipherListPBE() {
+			return cryptoCipherList("(PBE).*(WITH).+(AND).+");
+		}
+
+		static String securityProviderName(String algorithm) throws Exception {
+			return SecretKeyFactory.getInstance(algorithm).getProvider()
+					.getName();
+		}
+
+		static List<String> cryptoCipherList(String regex) {
+			Set<String> source = Security.getAlgorithms("Cipher");
+			Set<String> target = new TreeSet<String>();
+			for (String algo : source) {
+				algo = algo.toUpperCase();
+				if (algo.matches(regex)) {
+					target.add(algo);
+				}
+			}
+			return new ArrayList<String>(target);
+		}
+
+		/**
+		 * Verify if any security provider published the algorithm.
+		 *
+		 * @param algorithm
+		 * @return result
+		 */
+		static boolean isAlgorithmPresent(String algorithm) {
+			Set<String> cipherSet = Security.getAlgorithms("Cipher");
+			for (String source : cipherSet) {
+				// Standard names are not case-sensitive.
+				// http://docs.oracle.com/javase/8/docs/technotes/guides/security/StandardNames.html
+				String target = algorithm.toUpperCase();
+				if (source.equalsIgnoreCase(target)) {
+					return true;
+				}
+			}
+			return false;
+		}
+
+		/**
+		 * Stream copy.
+		 *
+		 * @param from
+		 * @param into
+		 * @return count
+		 * @throws IOException
+		 */
+		static long transferStream(InputStream from, OutputStream into)
+				throws IOException {
+			byte[] array = new byte[1 * 1024];
+			long total = 0;
+			while (true) {
+				int count = from.read(array);
+				if (count == -1) {
+					break;
+				}
+				into.write(array, 0, count);
+				total += count;
+			}
+			return total;
+		}
+
+		/**
+		 * Setup proxy during CI build.
+		 *
+		 * @throws Exception
+		 */
+		// https://wiki.eclipse.org/Hudson#Accessing_the_Internet_using_Proxy
+		// http://docs.oracle.com/javase/7/docs/api/java/net/doc-files/net-properties.html
+		static void proxySetup() throws Exception {
+			String keyNoProxy = "no_proxy";
+			String keyHttpProxy = "http_proxy";
+			String keyHttpsProxy = "https_proxy";
+
+			String no_proxy = System.getProperty(keyNoProxy,
+					System.getenv(keyNoProxy));
+			if (no_proxy != null) {
+				System.setProperty("http.nonProxyHosts", no_proxy);
+				logger.info("Proxy NOT: " + no_proxy);
+			}
+
+			String http_proxy = System.getProperty(keyHttpProxy,
+					System.getenv(keyHttpProxy));
+			if (http_proxy != null) {
+				URL url = new URL(http_proxy);
+				System.setProperty("http.proxyHost", url.getHost());
+				System.setProperty("http.proxyPort", "" + url.getPort());
+				logger.info("Proxy HTTP: " + http_proxy);
+			}
+
+			String https_proxy = System.getProperty(keyHttpsProxy,
+					System.getenv(keyHttpsProxy));
+			if (https_proxy != null) {
+				URL url = new URL(https_proxy);
+				System.setProperty("https.proxyHost", url.getHost());
+				System.setProperty("https.proxyPort", "" + url.getPort());
+				logger.info("Proxy HTTPS: " + https_proxy);
+			}
+
+			if (no_proxy == null && http_proxy == null && https_proxy == null) {
+				logger.info("Proxy not used.");
+			}
+
+		}
+
+		/**
+		 * Permit long tests on CI or with manual activation.
+		 *
+		 * @return result
+		 */
+		static boolean permitLongTests() {
+			return isBuildCI() || isProfileActive();
+		}
+
+		/**
+		 * Using Maven profile activation, see pom.xml
+		 *
+		 * @return result
+		 */
+		static boolean isProfileActive() {
+			return Boolean.parseBoolean(System.getProperty("jgit.test.long"));
+		}
+
+		/**
+		 * Detect if build is running on CI.
+		 *
+		 * @return result
+		 */
+		static boolean isBuildCI() {
+			return System.getenv("HUDSON_HOME") != null;
+		}
+
+	}
+
+	/**
+	 * Common base for encryption tests.
+	 */
+	@FixMethodOrder(MethodSorters.NAME_ASCENDING)
+	public abstract static class Base extends SampleDataRepositoryTestCase {
+
+		/**
+		 * S3 URI user used by JGIT to discover connection configuration file.
+		 */
+		static final String JGIT_USER = "tester-" + System.currentTimeMillis();
+
+		/**
+		 * S3 content encoding password used for this test session.
+		 */
+		static final String JGIT_PASS = "secret-" + System.currentTimeMillis();
+
+		/**
+		 * S3 repository configuration file expected by {@link AmazonS3}.
+		 */
+		static final String JGIT_CONF_FILE = System.getProperty("user.home")
+				+ "/" + JGIT_USER;
+
+		/**
+		 * Name representing remote or local JGIT repository.
+		 */
+		static final String JGIT_REPO_DIR = JGIT_USER + ".jgit";
+
+		/**
+		 * Local JGIT repository for this test session.
+		 */
+		static final String JGIT_LOCAL_DIR = System.getProperty("user.dir")
+				+ "/target/" + JGIT_REPO_DIR;
+
+		/**
+		 * Remote JGIT repository for this test session.
+		 */
+		static final String JGIT_REMOTE_DIR = JGIT_REPO_DIR;
+
+		/**
+		 * Generate JGIT S3 connection configuration file.
+		 *
+		 * @param algorithm
+		 * @throws Exception
+		 */
+		static void configCreate(String algorithm) throws Exception {
+			Properties props = Props.discover();
+			props.put(AmazonS3.Keys.PASSWORD, JGIT_PASS);
+			props.put(AmazonS3.Keys.CRYPTO_ALG, algorithm);
+			PrintWriter writer = new PrintWriter(JGIT_CONF_FILE);
+			props.store(writer, "JGIT S3 connection configuration file.");
+			writer.close();
+		}
+
+		/**
+		 * Remove JGIT connection configuration file.
+		 *
+		 * @throws Exception
+		 */
+		static void configDelete() throws Exception {
+			File path = new File(JGIT_CONF_FILE);
+			FileUtils.delete(path, FileUtils.SKIP_MISSING);
+		}
+
+		/**
+		 * Generate remote URI for the test session.
+		 *
+		 * @return result
+		 * @throws Exception
+		 */
+		static String amazonURI() throws Exception {
+			Properties props = Props.discover();
+			String bucket = props.getProperty(Names.TEST_BUCKET);
+			assertNotNull(bucket);
+			return TransportAmazonS3.S3_SCHEME + "://" + JGIT_USER + "@"
+					+ bucket + "/" + JGIT_REPO_DIR;
+		}
+
+		/**
+		 * Create S3 repository folder.
+		 *
+		 * @throws Exception
+		 */
+		static void remoteCreate() throws Exception {
+			Properties props = Props.discover();
+			props.remove(AmazonS3.Keys.PASSWORD); // Disable encryption.
+			String bucket = props.getProperty(Names.TEST_BUCKET);
+			AmazonS3 s3 = new AmazonS3(props);
+			String path = JGIT_REMOTE_DIR + "/";
+			s3.put(bucket, path, new byte[0]);
+			logger.debug("remote create: " + JGIT_REMOTE_DIR);
+		}
+
+		/**
+		 * Delete S3 repository folder.
+		 *
+		 * @throws Exception
+		 */
+		static void remoteDelete() throws Exception {
+			Properties props = Props.discover();
+			props.remove(AmazonS3.Keys.PASSWORD); // Disable encryption.
+			String bucket = props.getProperty(Names.TEST_BUCKET);
+			AmazonS3 s3 = new AmazonS3(props);
+			List<String> list = s3.list(bucket, JGIT_REMOTE_DIR);
+			for (String path : list) {
+				path = JGIT_REMOTE_DIR + "/" + path;
+				s3.delete(bucket, path);
+			}
+			logger.debug("remote delete: " + JGIT_REMOTE_DIR);
+		}
+
+		/**
+		 * Verify if we can create/delete remote file.
+		 *
+		 * @throws Exception
+		 */
+		static void remoteVerify() throws Exception {
+			Properties props = Props.discover();
+			String bucket = props.getProperty(Names.TEST_BUCKET);
+			AmazonS3 s3 = new AmazonS3(props);
+			String file = JGIT_USER + "-" + UUID.randomUUID().toString();
+			String path = JGIT_REMOTE_DIR + "/" + file;
+			s3.put(bucket, path, file.getBytes(UTF_8));
+			s3.delete(bucket, path);
+		}
+
+		/**
+		 * Verify if JRE security policy allows the algorithm.
+		 *
+		 * @param algorithm
+		 * @return result
+		 */
+		static boolean isAlgorithmAllowed(String algorithm) {
+			try {
+				WalkEncryption crypto = new WalkEncryption.ObjectEncryptionJetS3tV2(
+						algorithm, JGIT_PASS);
+				verifyCrypto(crypto);
+				return true;
+			} catch (IOException e) {
+				return false; // Encryption failure.
+			} catch (GeneralSecurityException e) {
+				throw new Error(e); // Construction failure.
+			}
+		}
+
+		/**
+		 * Verify round trip encryption.
+		 *
+		 * @param crypto
+		 * @throws IOException
+		 */
+		static void verifyCrypto(WalkEncryption crypto) throws IOException {
+			String charset = "UTF-8";
+			String sourceText = "secret-message Свобода 老子";
+			String targetText;
+			byte[] cipherText;
+			{
+				byte[] origin = sourceText.getBytes(charset);
+				ByteArrayOutputStream target = new ByteArrayOutputStream();
+				OutputStream source = crypto.encrypt(target);
+				source.write(origin);
+				source.flush();
+				source.close();
+				cipherText = target.toByteArray();
+			}
+			{
+				InputStream source = new ByteArrayInputStream(cipherText);
+				InputStream target = crypto.decrypt(source);
+				ByteArrayOutputStream result = new ByteArrayOutputStream();
+				transferStream(target, result);
+				targetText = result.toString(charset);
+			}
+			assertEquals(sourceText, targetText);
+		}
+
+		/**
+		 * Algorithm is testable when it is present and allowed by policy.
+		 *
+		 * @param algorithm
+		 * @return result
+		 */
+		static boolean isAlgorithmTestable(String algorithm) {
+			return isAlgorithmPresent(algorithm)
+					&& isAlgorithmAllowed(algorithm);
+		}
+
+		/**
+		 * Log algorithm, provider, testability.
+		 *
+		 * @param algorithm
+		 * @throws Exception
+		 */
+		static void reportAlgorithmStatus(String algorithm) throws Exception {
+			final boolean present = isAlgorithmPresent(algorithm);
+			final boolean allowed = present && isAlgorithmAllowed(algorithm);
+			final String provider = present ? securityProviderName(algorithm)
+					: "N/A";
+			String status = "Algorithm: " + algorithm + " @ " + provider + "; "
+					+ "present/allowed : " + present + "/" + allowed;
+			if (allowed) {
+				logger.info("Testing " + status);
+			} else {
+				logger.warn("Missing " + status);
+			}
+		}
+
+		/**
+		 * Verify if we can perform remote tests.
+		 *
+		 * @return result
+		 */
+		static boolean isTestConfigPresent() {
+			try {
+				Props.discover();
+				return true;
+			} catch (Throwable e) {
+				return false;
+			}
+		}
+
+		static void reportTestConfigPresent() {
+			if (isTestConfigPresent()) {
+				logger.info("Amazon S3 test configuration is present.");
+			} else {
+				logger.error(
+						"Amazon S3 test configuration is missing, tests will not run.");
+			}
+		}
+
+		/**
+		 * Log public address of CI.
+		 *
+		 * @throws Exception
+		 */
+		static void reportPublicAddress() throws Exception {
+			logger.info("Public address: " + publicAddress());
+		}
+
+		/**
+		 * BouncyCastle provider class.
+		 *
+		 * Needs extra dependency, see pom.xml
+		 */
+		// http://search.maven.org/#artifactdetails%7Corg.bouncycastle%7Cbcprov-jdk15on%7C1.52%7Cjar
+		static final String PROVIDER_BC = "org.bouncycastle.jce.provider.BouncyCastleProvider";
+
+		/**
+		 * Load BouncyCastle provider if present.
+		 */
+		static void loadBouncyCastle() {
+			try {
+				Class<?> provider = Class.forName(PROVIDER_BC);
+				Provider instance = (Provider) provider
+						.getConstructor(new Class[] {})
+						.newInstance(new Object[] {});
+				Security.addProvider(instance);
+				logger.info("Loaded " + PROVIDER_BC);
+			} catch (Throwable e) {
+				logger.warn("Failed to load " + PROVIDER_BC);
+			}
+		}
+
+		static void reportLongTests() {
+			if (permitLongTests()) {
+				logger.info("Long running tests are enabled.");
+			} else {
+				logger.warn("Long running tests are disabled.");
+			}
+		}
+
+		/**
+		 * Non-PBE algorithm, for error check.
+		 */
+		static final String ALGO_ERROR = "PBKDF2WithHmacSHA1";
+
+		/**
+		 * Default JetS3t algorithm present in most JRE.
+		 */
+		static final String ALGO_JETS3T = "PBEWithMD5AndDES";
+
+		/**
+		 * Minimal strength AES based algorithm present in most JRE.
+		 */
+		static final String ALGO_MINIMAL_AES = "PBEWithHmacSHA1AndAES_128";
+
+		/**
+		 * Selected non-AES algorithm present in BouncyCastle provider.
+		 */
+		static final String ALGO_BOUNCY_CASTLE_CBC = "PBEWithSHAAndTwofish-CBC";
+
+		//////////////////////////////////////////////////
+
+		@BeforeClass
+		public static void initialize() throws Exception {
+			Transport.register(TransportAmazonS3.PROTO_S3);
+			proxySetup();
+			reportLongTests();
+			reportPublicAddress();
+			reportTestConfigPresent();
+			loadBouncyCastle();
+			if (isTestConfigPresent()) {
+				remoteCreate();
+			}
+		}
+
+		@AfterClass
+		public static void terminate() throws Exception {
+			configDelete();
+			folderDelete(JGIT_LOCAL_DIR);
+			if (isTestConfigPresent()) {
+				remoteDelete();
+			}
+		}
+
+		@Before
+		@Override
+		public void setUp() throws Exception {
+			super.setUp();
+		}
+
+		@After
+		@Override
+		public void tearDown() throws Exception {
+			super.tearDown();
+		}
+
+		/**
+		 * Optional encrypted amazon remote JGIT life cycle test.
+		 *
+		 * @param algorithm
+		 * @throws Exception
+		 */
+		void cryptoTestIfCan(String algorithm) throws Exception {
+			reportAlgorithmStatus(algorithm);
+			assumeTrue(isTestConfigPresent());
+			assumeTrue(isAlgorithmTestable(algorithm));
+			cryptoTest(algorithm);
+		}
+
+		/**
+		 * Required encrypted amazon remote JGIT life cycle test.
+		 *
+		 * @param algorithm
+		 * @throws Exception
+		 */
+		void cryptoTest(String algorithm) throws Exception {
+
+			remoteDelete();
+			configCreate(algorithm);
+			folderDelete(JGIT_LOCAL_DIR);
+
+			String uri = amazonURI();
+
+			// Local repositories.
+			File dirOne = db.getWorkTree(); // Provided by setup.
+			File dirTwo = new File(JGIT_LOCAL_DIR);
+
+			// Local verification files.
+			String nameStatic = "master.txt"; // Provided by setup.
+			String nameDynamic = JGIT_USER + "-" + UUID.randomUUID().toString();
+
+			String remote = "remote";
+			RefSpec specs = new RefSpec("refs/heads/master:refs/heads/master");
+
+			{ // Push into remote from local one.
+
+				StoredConfig config = db.getConfig();
+				RemoteConfig remoteConfig = new RemoteConfig(config, remote);
+				remoteConfig.addURI(new URIish(uri));
+				remoteConfig.update(config);
+				config.save();
+
+				Git git = Git.open(dirOne);
+				git.checkout().setName("master").call();
+				git.push().setRemote(remote).setRefSpecs(specs).call();
+				git.close();
+
+				File fileStatic = new File(dirOne, nameStatic);
+				assertTrue("Provided by setup", fileStatic.exists());
+
+			}
+
+			{ // Clone from remote into local two.
+
+				File fileStatic = new File(dirTwo, nameStatic);
+				assertFalse("Not Provided by setup", fileStatic.exists());
+
+				Git git = Git.cloneRepository().setURI(uri).setDirectory(dirTwo)
+						.call();
+				git.close();
+
+				assertTrue("Provided by clone", fileStatic.exists());
+			}
+
+			{ // Verify static file content.
+				File fileOne = new File(dirOne, nameStatic);
+				File fileTwo = new File(dirTwo, nameStatic);
+				verifyFileContent(fileOne, fileTwo);
+			}
+
+			{ // Verify new file commit and push from local one.
+
+				File fileDynamic = new File(dirOne, nameDynamic);
+				assertFalse("Not Provided by setup", fileDynamic.exists());
+				FileUtils.createNewFile(fileDynamic);
+				textWrite(fileDynamic, nameDynamic);
+				assertTrue("Provided by create", fileDynamic.exists());
+				assertTrue("Need content to encrypt", fileDynamic.length() > 0);
+
+				Git git = Git.open(dirOne);
+				git.add().addFilepattern(nameDynamic).call();
+				git.commit().setMessage(nameDynamic).call();
+				git.push().setRemote(remote).setRefSpecs(specs).call();
+				git.close();
+
+			}
+
+			{ // Verify new file pull from remote into local two.
+
+				File fileDynamic = new File(dirTwo, nameDynamic);
+				assertFalse("Not Provided by setup", fileDynamic.exists());
+
+				Git git = Git.open(dirTwo);
+				git.pull().call();
+				git.close();
+
+				assertTrue("Provided by pull", fileDynamic.exists());
+			}
+
+			{ // Verify dynamic file content.
+				File fileOne = new File(dirOne, nameDynamic);
+				File fileTwo = new File(dirTwo, nameDynamic);
+				verifyFileContent(fileOne, fileTwo);
+			}
+
+		}
+
+	}
+
+	/**
+	 * Test minimal set of algorithms.
+	 */
+	@FixMethodOrder(MethodSorters.NAME_ASCENDING)
+	public static class MinimalSet extends Base {
+
+		@Test
+		public void test_A1_ValidURI() throws Exception {
+			assumeTrue(isTestConfigPresent());
+			URIish uri = new URIish(amazonURI());
+			assertTrue("uri=" + uri, TransportAmazonS3.PROTO_S3.canHandle(uri));
+		}
+
+		@Test(expected = Exception.class)
+		public void test_A2_CryptoError() throws Exception {
+			assumeTrue(isTestConfigPresent());
+			cryptoTest(ALGO_ERROR);
+		}
+
+		@Test
+		public void test_A3_CryptoJetS3tDefault() throws Exception {
+			cryptoTestIfCan(ALGO_JETS3T);
+		}
+
+		@Test
+		public void test_A4_CryptoMinimalAES() throws Exception {
+			cryptoTestIfCan(ALGO_MINIMAL_AES);
+		}
+
+		@Test
+		public void test_A5_CryptoBouncyCastleCBC() throws Exception {
+			cryptoTestIfCan(ALGO_BOUNCY_CASTLE_CBC);
+		}
+
+	}
+
+	/**
+	 * Test all present and allowed PBE algorithms.
+	 */
+	// https://github.com/junit-team/junit/wiki/Parameterized-tests
+	@RunWith(Parameterized.class)
+	@FixMethodOrder(MethodSorters.NAME_ASCENDING)
+	public static class TestablePBE extends Base {
+
+		@Parameters(name = "Algorithm: {0}")
+		public static Collection algorimthmList() {
+			List<String> source = cryptoCipherListPBE();
+			List<Object[]> target = new ArrayList<Object[]>();
+			for (String name : source) {
+				target.add(new Object[] { name });
+			}
+			return target;
+		}
+
+		final String algorithm;
+
+		public TestablePBE(String algorithm) {
+			this.algorithm = algorithm;
+		}
+
+		@Test // Can take long time, needs activation.
+		public void test_B1_Crypto() throws Exception {
+			assumeTrue(permitLongTests());
+			cryptoTestIfCan(algorithm);
+		}
+
+	}
+
+}