3 files changed, 121 insertions, 5 deletions

diff --git a/src/main/java/com/gitblit/models/UserModel.java b/src/main/java/com/gitblit/models/UserModel.java
index edbdf028..f8f7ed6d 100644
--- a/src/main/java/com/gitblit/models/UserModel.java
+++ b/src/main/java/com/gitblit/models/UserModel.java
@@ -37,6 +37,7 @@ import com.gitblit.Constants.PermissionType;
 import com.gitblit.Constants.RegistrantType;

 import com.gitblit.utils.ArrayUtils;

 import com.gitblit.utils.ModelUtils;

+import com.gitblit.utils.SecureRandom;

 import com.gitblit.utils.StringUtils;

 

 /**

@@ -53,6 +54,8 @@ public class UserModel implements Principal, Serializable, Comparable<UserModel>
 

 	public static final UserModel ANONYMOUS = new UserModel();

 

+	private static final SecureRandom RANDOM = new SecureRandom();

+

 	// field names are reflectively mapped in EditUser page

 	public String username;

 	public String password;

@@ -661,11 +664,8 @@ public class UserModel implements Principal, Serializable, Comparable<UserModel>
 		String projectPath = StringUtils.getFirstPathElement(repository);

 		return !StringUtils.isEmpty(projectPath) && projectPath.equalsIgnoreCase(getPersonalPath());

 	}

-	

+

 	public String createCookie() {

-		SecureRandom random = new SecureRandom();

-		byte[] values = new byte[20];

-		random.nextBytes(values);

-		return StringUtils.getSHA1(String.valueOf(values));

+		return StringUtils.getSHA1(RANDOM.randomBytes(32));

 	}

 }

diff --git a/src/main/java/com/gitblit/utils/SecureRandom.java b/src/main/java/com/gitblit/utils/SecureRandom.java
new file mode 100644
index 00000000..119533d4
--- /dev/null
+++ b/src/main/java/com/gitblit/utils/SecureRandom.java
@@ -0,0 +1,83 @@
+/*
+ * Copyright 2016 gitblit.com
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.gitblit.utils;
+
+/**
+ * Wrapper class for java.security.SecureRandom, which will periodically reseed
+ * the PRNG in case an instance of the class has been running for a long time.
+ *
+ * @author Florian Zschocke
+ */
+public class SecureRandom {
+
+	/** Period (in ms) after which a new SecureRandom will be created in order to get a fresh random seed. */
+	private static final long RESEED_PERIOD = 24 * 60 * 60 * 1000; /* 24 hours */
+
+
+	private long last;
+	private java.security.SecureRandom random;
+
+
+
+	public SecureRandom() {
+		// Make sure the SecureRandom is seeded right from the start.
+		// This also lets any blocks during seeding occur at creation
+		// and prevents it from happening when getting next random bytes.
+		seed();
+	}
+
+
+
+	public byte[] randomBytes(int num) {
+		byte[] bytes = new byte[num];
+		nextBytes(bytes);
+		return bytes;
+	}
+
+
+	public void nextBytes(byte[] bytes) {
+		random.nextBytes(bytes);
+		reseed(false);
+	}
+
+
+	void reseed(boolean forced) {
+		long ts = System.currentTimeMillis();
+		if (forced || (ts - last) > RESEED_PERIOD) {
+			last = ts;
+			runReseed();
+		}
+	}
+
+
+
+	private void seed() {
+		random = new java.security.SecureRandom();
+		random.nextBytes(new byte[0]);
+		last = System.currentTimeMillis();
+	}
+
+
+	private void runReseed() {
+		// Have some other thread hit the penalty potentially incurred by reseeding,
+		// so that we can immediately return and not block the operation in progress.
+		new Thread() {
+			public void run() {
+				seed();
+			}
+		}.start();
+	}
+}
diff --git a/src/test/java/com/gitblit/utils/SecureRandomTest.java b/src/test/java/com/gitblit/utils/SecureRandomTest.java
new file mode 100644
index 00000000..c4098c2f
--- /dev/null
+++ b/src/test/java/com/gitblit/utils/SecureRandomTest.java
@@ -0,0 +1,33 @@
+package com.gitblit.utils;
+
+import static org.junit.Assert.*;
+
+import java.util.Arrays;
+
+import org.junit.Test;
+
+public class SecureRandomTest {
+
+	@Test
+	public void testRandomBytes() {
+		SecureRandom sr = new SecureRandom();
+		byte[] bytes1 = sr.randomBytes(10);
+		assertEquals(10, bytes1.length);
+		byte[] bytes2 = sr.randomBytes(10);
+		assertEquals(10, bytes2.length);
+		assertFalse(Arrays.equals(bytes1, bytes2));
+
+		assertEquals(0, sr.randomBytes(0).length);
+		assertEquals(200, sr.randomBytes(200).length);
+	}
+
+	@Test
+	public void testNextBytes() {
+		SecureRandom sr = new SecureRandom();
+		byte[] bytes1 = new byte[32];
+		sr.nextBytes(bytes1);
+		byte[] bytes2 = new byte[32];
+		sr.nextBytes(bytes2);
+		assertFalse(Arrays.equals(bytes1, bytes2));
+	}
+}