changing Math.random to SecureRandom
diff --git a/src/main/java/com/gitblit/models/UserModel.java b/src/main/java/com/gitblit/models/UserModel.java
index d411e50..edbdf02 100644
--- a/src/main/java/com/gitblit/models/UserModel.java
+++ b/src/main/java/com/gitblit/models/UserModel.java
@@ -17,6 +17,7 @@
 

 import java.io.Serializable;

 import java.security.Principal;

+import java.security.SecureRandom;

 import java.util.ArrayList;

 import java.util.Collections;

 import java.util.HashSet;

@@ -662,6 +663,9 @@
 	}

 	

 	public String createCookie() {

-		return StringUtils.getSHA1(String.valueOf(Math.random()));

+		SecureRandom random = new SecureRandom();

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

+		random.nextBytes(values);

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

 	}

 }