LDAP-336 - Remove usage of internal class sun.misc.BASE64Encoder.

Replaced usage of sun.misc.BASE64Encoder/Decoder with a wrapping
implementation backed by JAXB's DatatypeConverter which is
available since Java 6. Introduced parseBase64Binary and printBase64Binary
to LdapEncoder as wrappers around DatatypeConverter which does additional line
wrapping as required by the RFC2849 for LDAP attributes.

core/src/main/java/org/springframework/ldap/support/LdapEncoder.java

@@ -17,12 +17,16 @@
 package org.springframework.ldap.support;
 
 import org.springframework.ldap.BadLdapGrammarException;
+import org.springframework.util.Assert;
+
+import javax.xml.bind.DatatypeConverter;
 
 /**
  * Helper class to encode and decode ldap names and values.
  * 
  * @author Adam Skogman
  * @author Mattias Hellborg Arthursson
+ * @author Thomas Darimont
  */
 public final class LdapEncoder {
 
@@ -31,6 +35,8 @@ public final class LdapEncoder {
 
     private static String[] FILTER_ESCAPE_TABLE = new String['\\' + 1];
 
+    private static final int RFC2849_MAX_BASE64_CHARS_PER_LINE = 76;
+    
     static {
 
         // Name encoding table -------------------------------------
@@ -229,4 +235,60 @@ public final class LdapEncoder {
         return decoded.toString();
 
     }
+
+    /**
+     * Converts an array of bytes into a Base64 encoded string according to the rules for converting LDAP Attributes in RFC2849.
+     *
+     * @param val
+     * @return
+     *   A string containing a lexical representation of base64Binary wrapped around 76 characters.
+     * @throws IllegalArgumentException if <tt>val</tt> is null.
+     */
+    public static String printBase64Binary(byte[] val) {
+
+        Assert.notNull(val, "val must not be null!");
+
+        String encoded = DatatypeConverter.printBase64Binary(val);
+
+        int length = encoded.length();
+        StringBuilder sb = new StringBuilder(length + length / RFC2849_MAX_BASE64_CHARS_PER_LINE);
+
+        for (int i = 0, len = length; i < len; i++) {
+            sb.append(encoded.charAt(i));
+
+            if ((i + 1) % RFC2849_MAX_BASE64_CHARS_PER_LINE == 0) {
+                sb.append('\n');
+            }
+        }
+
+        return sb.toString();
+    }
+
+    /**
+     * Converts the Base64 encoded string argument into an array of bytes.
+     *
+     * @param val
+     * @return
+     *   An array of bytes represented by the string argument.
+     * @throws IllegalArgumentException if <tt>val</tt> is null or does not conform to lexical value space defined in XML Schema Part 2: Datatypes for xsd:base64Binary.
+     */
+    public static byte[] parseBase64Binary(String val) {
+
+        Assert.notNull(val, "val must not be null!");
+
+        int length = val.length();
+        StringBuilder sb = new StringBuilder(length);
+        for (int i = 0, len = length; i < len; i++) {
+
+            char c = val.charAt(i);
+
+            if(c == '\n'){
+                continue;
+            }
+
+            sb.append(c);
+        }
+
+        return DatatypeConverter.parseBase64Binary(sb.toString());
+    }
 }