svn commit: r1458499 - in /commons/proper/fileupload/trunk/src: main/java/org/apache/commons/fileupload/util/mime/QuotedPrintableDecoder.java test/java/org/apache/commons/fileupload/util/mime/QuotedPrintableDecoderTestCase.java

[se...@apache.org]

Author: sebb
Date: Tue Mar 19 20:30:49 2013
New Revision: 1458499

URL: http://svn.apache.org/r1458499
Log:
Simplify hex conversion by using Character.digit() method.
This also supports lower case hex, and rejects invalid hex digits and eliminates the table data.
Update the test cases.

Modified:
    commons/proper/fileupload/trunk/src/main/java/org/apache/commons/fileupload/util/mime/QuotedPrintableDecoder.java
    commons/proper/fileupload/trunk/src/test/java/org/apache/commons/fileupload/util/mime/QuotedPrintableDecoderTestCase.java

Modified: commons/proper/fileupload/trunk/src/main/java/org/apache/commons/fileupload/util/mime/QuotedPrintableDecoder.java
URL: http://svn.apache.org/viewvc/commons/proper/fileupload/trunk/src/main/java/org/apache/commons/fileupload/util/mime/QuotedPrintableDecoder.java?rev=1458499&r1=1458498&r2=1458499&view=diff
==============================================================================
--- commons/proper/fileupload/trunk/src/main/java/org/apache/commons/fileupload/util/mime/QuotedPrintableDecoder.java (original)
+++ commons/proper/fileupload/trunk/src/main/java/org/apache/commons/fileupload/util/mime/QuotedPrintableDecoder.java Tue Mar 19 20:30:49 2013
@@ -25,34 +25,12 @@ import java.io.OutputStream;
 final class QuotedPrintableDecoder {
 
     /**
-     * Set up the encoding table.
-     */
-    private static final byte[] ENCODING_TABLE = {
-        (byte) '0', (byte) '1', (byte) '2', (byte) '3', (byte) '4', (byte) '5', (byte) '6', (byte) '7',
-        (byte) '8', (byte) '9', (byte) 'A', (byte) 'B', (byte) 'C', (byte) 'D', (byte) 'E', (byte) 'F'
-    };
-
-    /**
      * The shift value required to create the upper nibble
      * from the first of 2 byte values converted from ascii hex.
      */
     private static final int UPPER_NIBBLE_SHIFT = Byte.SIZE / 2;
 
     /**
-     * Set up the decoding table; this is indexed by a byte converted to an int,
-     * so must be at least as large as the number of different byte values,
-     * positive and negative and zero.
-     */
-    private static final byte[] DECODING_TABLE = new byte[Byte.MAX_VALUE - Byte.MIN_VALUE + 1];
-
-    static {
-        // initialize the decoding table
-        for (int i = 0; i < ENCODING_TABLE.length; i++) {
-            DECODING_TABLE[ENCODING_TABLE[i]] = (byte) i;
-        }
-    }
-
-    /**
      * Hidden constructor, this class must not be instantiated.
      */
     private QuotedPrintableDecoder() {
@@ -99,8 +77,8 @@ final class QuotedPrintableDecoder {
                     // on decode.
                 } else {
                     // this is a hex pair we need to convert back to a single byte.
-                    byte c1 = DECODING_TABLE[b1];
-                    byte c2 = DECODING_TABLE[b2];
+                    int c1 = hexToBinary(b1);
+                    int c2 = hexToBinary(b2);
                     out.write((c1 << UPPER_NIBBLE_SHIFT) | c2);
                     // 3 bytes in, one byte out
                     bytesWritten++;
@@ -115,4 +93,20 @@ final class QuotedPrintableDecoder {
         return bytesWritten;
     }
 
+    /**
+     * Convert a hex digit to the binary value it represents.
+     * 
+     * @param b the ascii hex byte to convert (0-0, A-F, a-f)
+     * @return the int value of the hex byte, 0-15
+     * @throws IOException if the byte is not a valid hex digit.
+     */
+    private static int hexToBinary(final byte b) throws IOException {
+        // CHECKSTYLE IGNORE MagicNumber FOR NEXT 1 LINE
+        final int i = Character.digit((char) b, 16);
+        if (i == -1) {
+            throw new IOException("Invalid quoted printable encoding: not a valid hex digit: " + b);
+        }
+        return i;
+    }
+
 }

Modified: commons/proper/fileupload/trunk/src/test/java/org/apache/commons/fileupload/util/mime/QuotedPrintableDecoderTestCase.java
URL: http://svn.apache.org/viewvc/commons/proper/fileupload/trunk/src/test/java/org/apache/commons/fileupload/util/mime/QuotedPrintableDecoderTestCase.java?rev=1458499&r1=1458498&r2=1458499&view=diff
==============================================================================
--- commons/proper/fileupload/trunk/src/test/java/org/apache/commons/fileupload/util/mime/QuotedPrintableDecoderTestCase.java (original)
+++ commons/proper/fileupload/trunk/src/test/java/org/apache/commons/fileupload/util/mime/QuotedPrintableDecoderTestCase.java Tue Mar 19 20:30:49 2013
@@ -48,6 +48,16 @@ public final class QuotedPrintableDecode
         assertEncoded("=\r\n", "=3D=0D=0A");
     }
 
+    @Test
+    public void unsafeDecodeLowerCase() throws Exception {
+        assertEncoded("=\r\n", "=3d=0d=0a");
+    }
+
+    @Test(expected = IOException.class)
+    public void invalidCharDecode() throws Exception {
+        assertEncoded("=\r\n", "=3D=XD=XA");
+    }
+
     /**
      * This is NOT supported by Commons-Codec, see CODEC-121.
      *