Moved MD5 encoding routine into StringUtil.

git-svn-id: https://samskivert.googlecode.com/svn/trunk@864 6335cc39-0255-0410-8fd6-9bcaacd3b74c

projects/samskivert/src/java/com/samskivert/servlet/user/UserUtil.java

@@ -1,5 +1,5 @@
 //
-// $Id: UserUtil.java,v 1.4 2001/08/11 22:43:28 mdb Exp $
+// $Id: UserUtil.java,v 1.5 2002/10/16 00:42:26 mdb Exp $
 //
 // samskivert library - useful routines for java programs
 // Copyright (C) 2001 Michael Bayne
@@ -20,8 +20,6 @@
 
 package com.samskivert.servlet.user;
 
-import java.security.*;
-
 import com.samskivert.util.Crypt;
 import com.samskivert.util.StringUtil;
 
@@ -42,17 +40,14 @@ public class UserUtil
 	buf.append(Math.random());
 
 	// and MD5 hash it
-	try {
-	    MessageDigest digest = MessageDigest.getInstance("MD5");
-	    byte[] enc = digest.digest(buf.toString().getBytes());
-	    return StringUtil.hexlate(enc);
-
-	} catch (NoSuchAlgorithmException nsae) {
+        String auth = StringUtil.md5hex(buf.toString());
+        if (auth == null) {
 	    throw new RuntimeException("JVM missing MD5 message digest " +
 				       "algorithm implementation. User " +
 				       "management facilities require MD5 " +
 				       "encoding capabilities.");
-	}
+        }
+        return auth;
     }
 
     /**

projects/samskivert/src/java/com/samskivert/util/StringUtil.java

@@ -1,5 +1,5 @@
 //
-// $Id: StringUtil.java,v 1.37 2002/09/24 07:43:50 mdb Exp $
+// $Id: StringUtil.java,v 1.38 2002/10/16 00:42:26 mdb Exp $
 //
 // samskivert library - useful routines for java programs
 // Copyright (C) 2001 Michael Bayne
@@ -29,6 +29,9 @@ import java.lang.reflect.Modifier;
 
 import java.net.InetAddress;
 
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+
 import java.util.Collection;
 import java.util.Enumeration;
 import java.util.Iterator;
@@ -575,6 +578,20 @@ public class StringUtil
         return (bytes == null) ? "" : hexlate(bytes, bytes.length);
     }
 
+    /**
+     * Returns a hex string representing the MD5 encoded source or null if
+     * the MD5 codec was not available in this JVM.
+     */
+    public static String md5hex (String source)
+    {
+	try {
+	    MessageDigest digest = MessageDigest.getInstance("MD5");
+	    return hexlate(digest.digest(source.getBytes()));
+	} catch (NoSuchAlgorithmException nsae) {
+            return null;
+	}
+    }
+
     /**
      * Parses an array of integers from it's string representation. The
      * array should be represented as a bare list of numbers separated by