+ * For internal use only. + * + * @author Luke Taylor + * @since 3.0 + * @deprecated Use java.util.Base64 + */ +public final class Base64 { + + /** No options specified. Value is zero. */ + public final static int NO_OPTIONS = 0; + + /** Specify encoding in first bit. Value is one. */ + public final static int ENCODE = 1; + + /** Specify decoding in first bit. Value is zero. */ + public final static int DECODE = 0; + + /** Do break lines when encoding. Value is 8. */ + public final static int DO_BREAK_LINES = 8; + + /** + * Encode using Base64-like encoding that is URL- and Filename-safe as described in + * Section 4 of RFC3548: http://www.faqs + * .org/rfcs/rfc3548.html. It is important to note that data encoded this way is + * not officially valid Base64, or at the very least should not be called + * Base64 without also specifying that is was encoded using the URL- and Filename-safe + * dialect. + */ + public final static int URL_SAFE = 16; + + /** + * Encode using the special "ordered" dialect of Base64 described here: http://www.faqs.org/qa/rfcc-1940.html. + */ + public final static int ORDERED = 32; + + /** Maximum line length (76) of Base64 output. */ + private final static int MAX_LINE_LENGTH = 76; + + /** The equals sign (=) as a byte. */ + private final static byte EQUALS_SIGN = (byte) '='; + + /** The new line character (\n) as a byte. */ + private final static byte NEW_LINE = (byte) '\n'; + + private final static byte WHITE_SPACE_ENC = -5; // Indicates white space in encoding + private final static byte EQUALS_SIGN_ENC = -1; // Indicates equals sign in encoding + + /* ******** S T A N D A R D B A S E 6 4 A L P H A B E T ******** */ + + /** The 64 valid Base64 values. */ + /* Host platform me be something funny like EBCDIC, so we hardcode these values. */ + private final static byte[] _STANDARD_ALPHABET = { (byte) 'A', (byte) 'B', + (byte) 'C', (byte) 'D', (byte) 'E', (byte) 'F', (byte) 'G', (byte) 'H', + (byte) 'I', (byte) 'J', (byte) 'K', (byte) 'L', (byte) 'M', (byte) 'N', + (byte) 'O', (byte) 'P', (byte) 'Q', (byte) 'R', (byte) 'S', (byte) 'T', + (byte) 'U', (byte) 'V', (byte) 'W', (byte) 'X', (byte) 'Y', (byte) 'Z', + (byte) 'a', (byte) 'b', (byte) 'c', (byte) 'd', (byte) 'e', (byte) 'f', + (byte) 'g', (byte) 'h', (byte) 'i', (byte) 'j', (byte) 'k', (byte) 'l', + (byte) 'm', (byte) 'n', (byte) 'o', (byte) 'p', (byte) 'q', (byte) 'r', + (byte) 's', (byte) 't', (byte) 'u', (byte) 'v', (byte) 'w', (byte) 'x', + (byte) 'y', (byte) 'z', (byte) '0', (byte) '1', (byte) '2', (byte) '3', + (byte) '4', (byte) '5', (byte) '6', (byte) '7', (byte) '8', (byte) '9', + (byte) '+', (byte) '/' }; + + /** + * Translates a Base64 value to either its 6-bit reconstruction value or a negative + * number indicating some other meaning. + **/ + private final static byte[] _STANDARD_DECODABET = { -9, -9, -9, -9, -9, -9, -9, -9, + -9, // Decimal 0 - 8 + -5, -5, // Whitespace: Tab and Linefeed + -9, -9, // Decimal 11 - 12 + -5, // Whitespace: Carriage Return + -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 14 - 26 + -9, -9, -9, -9, -9, // Decimal 27 - 31 + -5, // Whitespace: Space + -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 33 - 42 + 62, // Plus sign at decimal 43 + -9, -9, -9, // Decimal 44 - 46 + 63, // Slash at decimal 47 + 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, // Numbers zero through nine + -9, -9, -9, // Decimal 58 - 60 + -1, // Equals sign at decimal 61 + -9, -9, -9, // Decimal 62 - 64 + 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, // Letters 'A' through 'N' + 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, // Letters 'O' through 'Z' + -9, -9, -9, -9, -9, -9, // Decimal 91 - 96 + 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, // Letters 'a' through 'm' + 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, // Letters 'n' through 'z' + -9, -9, -9, -9, -9 // Decimal 123 - 127 + , -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 128 - 139 + -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 140 - 152 + -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 153 - 165 + -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 166 - 178 + -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 179 - 191 + -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 192 - 204 + -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 205 - 217 + -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 218 - 230 + -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 231 - 243 + -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9 // Decimal 244 - 255 + }; + + /* ******** U R L S A F E B A S E 6 4 A L P H A B E T ******** */ + + /** + * Used in the URL- and Filename-safe dialect described in Section 4 of RFC3548: http://www.faqs.org/rfcs/rfc3548.html. + * Notice that the last two bytes become "hyphen" and "underscore" instead of "plus" + * and "slash." + */ + private final static byte[] _URL_SAFE_ALPHABET = { (byte) 'A', (byte) 'B', + (byte) 'C', (byte) 'D', (byte) 'E', (byte) 'F', (byte) 'G', (byte) 'H', + (byte) 'I', (byte) 'J', (byte) 'K', (byte) 'L', (byte) 'M', (byte) 'N', + (byte) 'O', (byte) 'P', (byte) 'Q', (byte) 'R', (byte) 'S', (byte) 'T', + (byte) 'U', (byte) 'V', (byte) 'W', (byte) 'X', (byte) 'Y', (byte) 'Z', + (byte) 'a', (byte) 'b', (byte) 'c', (byte) 'd', (byte) 'e', (byte) 'f', + (byte) 'g', (byte) 'h', (byte) 'i', (byte) 'j', (byte) 'k', (byte) 'l', + (byte) 'm', (byte) 'n', (byte) 'o', (byte) 'p', (byte) 'q', (byte) 'r', + (byte) 's', (byte) 't', (byte) 'u', (byte) 'v', (byte) 'w', (byte) 'x', + (byte) 'y', (byte) 'z', (byte) '0', (byte) '1', (byte) '2', (byte) '3', + (byte) '4', (byte) '5', (byte) '6', (byte) '7', (byte) '8', (byte) '9', + (byte) '-', (byte) '_' }; + + /** + * Used in decoding URL- and Filename-safe dialects of Base64. + */ + private final static byte[] _URL_SAFE_DECODABET = { -9, -9, -9, -9, -9, -9, -9, -9, + -9, // Decimal 0 - 8 + -5, -5, // Whitespace: Tab and Linefeed + -9, -9, // Decimal 11 - 12 + -5, // Whitespace: Carriage Return + -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 14 - 26 + -9, -9, -9, -9, -9, // Decimal 27 - 31 + -5, // Whitespace: Space + -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 33 - 42 + -9, // Plus sign at decimal 43 + -9, // Decimal 44 + 62, // Minus sign at decimal 45 + -9, // Decimal 46 + -9, // Slash at decimal 47 + 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, // Numbers zero through nine + -9, -9, -9, // Decimal 58 - 60 + -1, // Equals sign at decimal 61 + -9, -9, -9, // Decimal 62 - 64 + 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, // Letters 'A' through 'N' + 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, // Letters 'O' through 'Z' + -9, -9, -9, -9, // Decimal 91 - 94 + 63, // Underscore at decimal 95 + -9, // Decimal 96 + 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, // Letters 'a' through 'm' + 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, // Letters 'n' through 'z' + -9, -9, -9, -9, -9 // Decimal 123 - 127 + , -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 128 - 139 + -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 140 - 152 + -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 153 - 165 + -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 166 - 178 + -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 179 - 191 + -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 192 - 204 + -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 205 - 217 + -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 218 - 230 + -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 231 - 243 + -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9 // Decimal 244 - 255 + }; + + /* ******** O R D E R E D B A S E 6 4 A L P H A B E T ******** */ + + /** + * I don't get the point of this technique, but someone requested it, and it is + * described here: http://www.faqs.org/ + * qa/rfcc-1940.html. + */ + private final static byte[] _ORDERED_ALPHABET = { (byte) '-', (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', (byte) 'G', (byte) 'H', (byte) 'I', (byte) 'J', + (byte) 'K', (byte) 'L', (byte) 'M', (byte) 'N', (byte) 'O', (byte) 'P', + (byte) 'Q', (byte) 'R', (byte) 'S', (byte) 'T', (byte) 'U', (byte) 'V', + (byte) 'W', (byte) 'X', (byte) 'Y', (byte) 'Z', (byte) '_', (byte) 'a', + (byte) 'b', (byte) 'c', (byte) 'd', (byte) 'e', (byte) 'f', (byte) 'g', + (byte) 'h', (byte) 'i', (byte) 'j', (byte) 'k', (byte) 'l', (byte) 'm', + (byte) 'n', (byte) 'o', (byte) 'p', (byte) 'q', (byte) 'r', (byte) 's', + (byte) 't', (byte) 'u', (byte) 'v', (byte) 'w', (byte) 'x', (byte) 'y', + (byte) 'z' }; + + /** + * Used in decoding the "ordered" dialect of Base64. + */ + private final static byte[] _ORDERED_DECODABET = { -9, -9, -9, -9, -9, -9, -9, -9, + -9, // Decimal 0 - 8 + -5, -5, // Whitespace: Tab and Linefeed + -9, -9, // Decimal 11 - 12 + -5, // Whitespace: Carriage Return + -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 14 - 26 + -9, -9, -9, -9, -9, // Decimal 27 - 31 + -5, // Whitespace: Space + -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 33 - 42 + -9, // Plus sign at decimal 43 + -9, // Decimal 44 + 0, // Minus sign at decimal 45 + -9, // Decimal 46 + -9, // Slash at decimal 47 + 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, // Numbers zero through nine + -9, -9, -9, // Decimal 58 - 60 + -1, // Equals sign at decimal 61 + -9, -9, -9, // Decimal 62 - 64 + 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, // Letters 'A' through 'M' + 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, // Letters 'N' through 'Z' + -9, -9, -9, -9, // Decimal 91 - 94 + 37, // Underscore at decimal 95 + -9, // Decimal 96 + 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, // Letters 'a' through 'm' + 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, // Letters 'n' through 'z' + -9, -9, -9, -9, -9 // Decimal 123 - 127 + , -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 128 - 139 + -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 140 - 152 + -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 153 - 165 + -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 166 - 178 + -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 179 - 191 + -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 192 - 204 + -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 205 - 217 + -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 218 - 230 + -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 231 - 243 + -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9 // Decimal 244 - 255 + }; + + public static byte[] decode(byte[] bytes) { + return decode(bytes, 0, bytes.length, NO_OPTIONS); + } + + public static byte[] encode(byte[] bytes) { + return encodeBytesToBytes(bytes, 0, bytes.length, NO_OPTIONS); + } + + public static boolean isBase64(byte[] bytes) { + try { + decode(bytes); + } + catch (InvalidBase64CharacterException e) { + return false; + } + return true; + } + + /** + * Returns one of the _SOMETHING_ALPHABET byte arrays depending on the options + * specified. It's possible, though silly, to specify ORDERED and URLSAFE in + * which case one of them will be picked, though there is no guarantee as to which one + * will be picked. + */ + private static byte[] getAlphabet(int options) { + if ((options & URL_SAFE) == URL_SAFE) { + return _URL_SAFE_ALPHABET; + } + else if ((options & ORDERED) == ORDERED) { + return _ORDERED_ALPHABET; + } + else { + return _STANDARD_ALPHABET; + } + } + + /** + * Returns one of the _SOMETHING_DECODABET byte arrays depending on the options + * specified. It's possible, though silly, to specify ORDERED and URL_SAFE in which + * case one of them will be picked, though there is no guarantee as to which one will + * be picked. + */ + private static byte[] getDecodabet(int options) { + if ((options & URL_SAFE) == URL_SAFE) { + return _URL_SAFE_DECODABET; + } + else if ((options & ORDERED) == ORDERED) { + return _ORDERED_DECODABET; + } + else { + return _STANDARD_DECODABET; + } + } + + /* ******** E N C O D I N G M E T H O D S ******** */ + + /** + *
+ * Encodes up to three bytes of the array source and writes the resulting + * four Base64 bytes to destination. The source and destination arrays can + * be manipulated anywhere along their length by specifying srcOffset and + * destOffset. This method does not check to make sure your arrays are + * large enough to accomodate srcOffset + 3 for the source array + * or destOffset + 4 for the destination array. The actual + * number of significant bytes in your array is given by numSigBytes. + *
+ *+ * This is the lowest level of the encoding methods with all possible parameters. + *
+ * + * @param source the array to convert + * @param srcOffset the index where conversion begins + * @param numSigBytes the number of significant bytes in your array + * @param destination the array to hold the conversion + * @param destOffset the index where output will be put + * @return the destination array + * @since 1.3 + */ + private static byte[] encode3to4(byte[] source, int srcOffset, int numSigBytes, + byte[] destination, int destOffset, int options) { + + byte[] ALPHABET = getAlphabet(options); + + // 1 2 3 + // 01234567890123456789012345678901 Bit position + // --------000000001111111122222222 Array position from threeBytes + // --------| || || || | Six bit groups to index ALPHABET + // >>18 >>12 >> 6 >> 0 Right shift necessary + // 0x3f 0x3f 0x3f Additional AND + + // Create buffer with zero-padding if there are only one or two + // significant bytes passed in the array. + // We have to shift left 24 in order to flush out the 1's that appear + // when Java treats a value as negative that is cast from a byte to an int. + int inBuff = (numSigBytes > 0 ? ((source[srcOffset] << 24) >>> 8) : 0) + | (numSigBytes > 1 ? ((source[srcOffset + 1] << 24) >>> 16) : 0) + | (numSigBytes > 2 ? ((source[srcOffset + 2] << 24) >>> 24) : 0); + + switch (numSigBytes) { + case 3: + destination[destOffset] = ALPHABET[(inBuff >>> 18)]; + destination[destOffset + 1] = ALPHABET[(inBuff >>> 12) & 0x3f]; + destination[destOffset + 2] = ALPHABET[(inBuff >>> 6) & 0x3f]; + destination[destOffset + 3] = ALPHABET[(inBuff) & 0x3f]; + return destination; + + case 2: + destination[destOffset] = ALPHABET[(inBuff >>> 18)]; + destination[destOffset + 1] = ALPHABET[(inBuff >>> 12) & 0x3f]; + destination[destOffset + 2] = ALPHABET[(inBuff >>> 6) & 0x3f]; + destination[destOffset + 3] = EQUALS_SIGN; + return destination; + + case 1: + destination[destOffset] = ALPHABET[(inBuff >>> 18)]; + destination[destOffset + 1] = ALPHABET[(inBuff >>> 12) & 0x3f]; + destination[destOffset + 2] = EQUALS_SIGN; + destination[destOffset + 3] = EQUALS_SIGN; + return destination; + + default: + return destination; + } + } + + /** + * + * @param source The data to convert + * @param off Offset in array where conversion should begin + * @param len Length of data to convert + * @param options Specified options + * @return The Base64-encoded data as a String + * @see Base64#DO_BREAK_LINES + * @throws java.io.IOException if there is an error + * @throws NullPointerException if source array is null + * @throws IllegalArgumentException if source array, offset, or length are invalid + * @since 2.3.1 + */ + private static byte[] encodeBytesToBytes(byte[] source, int off, int len, int options) { + + if (source == null) { + throw new NullPointerException("Cannot serialize a null array."); + } // end if: null + + if (off < 0) { + throw new IllegalArgumentException("Cannot have negative offset: " + off); + } // end if: off < 0 + + if (len < 0) { + throw new IllegalArgumentException("Cannot have length offset: " + len); + } // end if: len < 0 + + if (off + len > source.length) { + throw new IllegalArgumentException(String.format( + "Cannot have offset of %d and length of %d with array of length %d", + off, len, source.length)); + } // end if: off < 0 + + boolean breakLines = (options & DO_BREAK_LINES) > 0; + + // int len43 = len * 4 / 3; + // byte[] outBuff = new byte[ ( len43 ) // Main 4:3 + // + ( (len % 3) > 0 ? 4 : 0 ) // Account for padding + // + (breakLines ? ( len43 / MAX_LINE_LENGTH ) : 0) ]; // New lines + // Try to determine more precisely how big the array needs to be. + // If we get it right, we don't have to do an array copy, and + // we save a bunch of memory. + int encLen = (len / 3) * 4 + (len % 3 > 0 ? 4 : 0); // Bytes needed for actual + // encoding + if (breakLines) { + encLen += encLen / MAX_LINE_LENGTH; // Plus extra newline characters + } + byte[] outBuff = new byte[encLen]; + + int d = 0; + int e = 0; + int len2 = len - 2; + int lineLength = 0; + for (; d < len2; d += 3, e += 4) { + encode3to4(source, d + off, 3, outBuff, e, options); + + lineLength += 4; + if (breakLines && lineLength >= MAX_LINE_LENGTH) { + outBuff[e + 4] = NEW_LINE; + e++; + lineLength = 0; + } // end if: end of line + } // en dfor: each piece of array + + if (d < len) { + encode3to4(source, d + off, len - d, outBuff, e, options); + e += 4; + } // end if: some padding needed + + // Only resize array if we didn't guess it right. + if (e <= outBuff.length - 1) { + byte[] finalOut = new byte[e]; + System.arraycopy(outBuff, 0, finalOut, 0, e); + // System.err.println("Having to resize array from " + outBuff.length + " to " + // + e ); + return finalOut; + } + else { + // System.err.println("No need to resize array."); + return outBuff; + } + } + + /* ******** D E C O D I N G M E T H O D S ******** */ + + /** + * Decodes four bytes from array source and writes the resulting bytes (up + * to three of them) to destination. The source and destination arrays can + * be manipulated anywhere along their length by specifying srcOffset and + * destOffset. This method does not check to make sure your arrays are + * large enough to accomodate srcOffset + 4 for the source array + * or destOffset + 3 for the destination array. This method + * returns the actual number of bytes that were converted from the Base64 encoding. + *+ * This is the lowest level of the decoding methods with all possible parameters. + *
+ * + * + * @param source the array to convert + * @param srcOffset the index where conversion begins + * @param destination the array to hold the conversion + * @param destOffset the index where output will be put + * @param options alphabet type is pulled from this (standard, url-safe, ordered) + * @return the number of decoded bytes converted + * @throws NullPointerException if source or destination arrays are null + * @throws IllegalArgumentException if srcOffset or destOffset are invalid or there is + * not enough room in the array. + * @since 1.3 + */ + private static int decode4to3(final byte[] source, final int srcOffset, + final byte[] destination, final int destOffset, final int options) { + + // Lots of error checking and exception throwing + if (source == null) { + throw new NullPointerException("Source array was null."); + } // end if + if (destination == null) { + throw new NullPointerException("Destination array was null."); + } // end if + if (srcOffset < 0 || srcOffset + 3 >= source.length) { + throw new IllegalArgumentException( + String.format( + "Source array with length %d cannot have offset of %d and still process four bytes.", + source.length, srcOffset)); + } // end if + if (destOffset < 0 || destOffset + 2 >= destination.length) { + throw new IllegalArgumentException( + String.format( + "Destination array with length %d cannot have offset of %d and still store three bytes.", + destination.length, destOffset)); + } // end if + + byte[] DECODABET = getDecodabet(options); + + // Example: Dk== + if (source[srcOffset + 2] == EQUALS_SIGN) { + // Two ways to do the same thing. Don't know which way I like best. + // int outBuff = ( ( DECODABET[ source[ srcOffset ] ] << 24 ) >>> 6 ) + // | ( ( DECODABET[ source[ srcOffset + 1] ] << 24 ) >>> 12 ); + int outBuff = ((DECODABET[source[srcOffset]] & 0xFF) << 18) + | ((DECODABET[source[srcOffset + 1]] & 0xFF) << 12); + + destination[destOffset] = (byte) (outBuff >>> 16); + return 1; + } + + // Example: DkL= + else if (source[srcOffset + 3] == EQUALS_SIGN) { + // Two ways to do the same thing. Don't know which way I like best. + // int outBuff = ( ( DECODABET[ source[ srcOffset ] ] << 24 ) >>> 6 ) + // | ( ( DECODABET[ source[ srcOffset + 1 ] ] << 24 ) >>> 12 ) + // | ( ( DECODABET[ source[ srcOffset + 2 ] ] << 24 ) >>> 18 ); + int outBuff = ((DECODABET[source[srcOffset]] & 0xFF) << 18) + | ((DECODABET[source[srcOffset + 1]] & 0xFF) << 12) + | ((DECODABET[source[srcOffset + 2]] & 0xFF) << 6); + + destination[destOffset] = (byte) (outBuff >>> 16); + destination[destOffset + 1] = (byte) (outBuff >>> 8); + return 2; + } + + // Example: DkLE + else { + // Two ways to do the same thing. Don't know which way I like best. + // int outBuff = ( ( DECODABET[ source[ srcOffset ] ] << 24 ) >>> 6 ) + // | ( ( DECODABET[ source[ srcOffset + 1 ] ] << 24 ) >>> 12 ) + // | ( ( DECODABET[ source[ srcOffset + 2 ] ] << 24 ) >>> 18 ) + // | ( ( DECODABET[ source[ srcOffset + 3 ] ] << 24 ) >>> 24 ); + int outBuff = ((DECODABET[source[srcOffset]] & 0xFF) << 18) + | ((DECODABET[source[srcOffset + 1]] & 0xFF) << 12) + | ((DECODABET[source[srcOffset + 2]] & 0xFF) << 6) + | ((DECODABET[source[srcOffset + 3]] & 0xFF)); + + destination[destOffset] = (byte) (outBuff >> 16); + destination[destOffset + 1] = (byte) (outBuff >> 8); + destination[destOffset + 2] = (byte) (outBuff); + + return 3; + } + } + + /** + * Low-level access to decoding ASCII characters in the form of a byte array. + * Ignores GUNZIP option, if it's set. This is not generally a + * recommended method, although it is used internally as part of the decoding process. + * Special case: if len = 0, an empty array is returned. Still, if you need more speed + * and reduced memory footprint (and aren't gzipping), consider this method. + * + * @param source The Base64 encoded data + * @param off The offset of where to begin decoding + * @param len The length of characters to decode + * @param options Can specify options such as alphabet type to use + * @return decoded data + * @throws IllegalArgumentException If bogus characters exist in source data + */ + private static byte[] decode(final byte[] source, final int off, final int len, + final int options) { + + // Lots of error checking and exception throwing + if (source == null) { + throw new NullPointerException("Cannot decode null source array."); + } // end if + if (off < 0 || off + len > source.length) { + throw new IllegalArgumentException( + String.format( + "Source array with length %d cannot have offset of %d and process %d bytes.", + source.length, off, len)); + } // end if + + if (len == 0) { + return new byte[0]; + } + else if (len < 4) { + throw new IllegalArgumentException( + "Base64-encoded string must have at least four characters, but length specified was " + + len); + } // end if + + byte[] DECODABET = getDecodabet(options); + + int len34 = len * 3 / 4; // Estimate on array size + byte[] outBuff = new byte[len34]; // Upper limit on size of output + int outBuffPosn = 0; // Keep track of where we're writing + + byte[] b4 = new byte[4]; // Four byte buffer from source, eliminating white space + int b4Posn = 0; // Keep track of four byte input buffer + int i = 0; // Source array counter + byte sbiDecode = 0; // Special value from DECODABET + + for (i = off; i < off + len; i++) { // Loop through source + + sbiDecode = DECODABET[source[i] & 0xFF]; + + // White space, Equals sign, or legit Base64 character + // Note the values such as -5 and -9 in the + // DECODABETs at the top of the file. + if (sbiDecode >= WHITE_SPACE_ENC) { + if (sbiDecode >= EQUALS_SIGN_ENC) { + b4[b4Posn++] = source[i]; // Save non-whitespace + if (b4Posn > 3) { // Time to decode? + outBuffPosn += decode4to3(b4, 0, outBuff, outBuffPosn, options); + b4Posn = 0; + + // If that was the equals sign, break out of 'for' loop + if (source[i] == EQUALS_SIGN) { + break; + } + } + } + } + else { + // There's a bad input character in the Base64 stream. + throw new InvalidBase64CharacterException(String.format( + "Bad Base64 input character decimal %d in array position %d", + ((int) source[i]) & 0xFF, i)); + } + } + + byte[] out = new byte[outBuffPosn]; + System.arraycopy(outBuff, 0, out, 0, outBuffPosn); + return out; + } +} + +class InvalidBase64CharacterException extends IllegalArgumentException { + + InvalidBase64CharacterException(String message) { + super(message); + } +} diff --git a/crypto/src/test/java/org/springframework/security/crypto/codec/Base64Tests.java b/crypto/src/test/java/org/springframework/security/crypto/codec/Base64Tests.java new file mode 100644 index 0000000000..c45a50bc21 --- /dev/null +++ b/crypto/src/test/java/org/springframework/security/crypto/codec/Base64Tests.java @@ -0,0 +1,51 @@ +/* + * Copyright 2002-2016 the original author or authors. + * + * 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 org.springframework.security.crypto.codec; + +import static org.assertj.core.api.Assertions.*; + +import org.junit.*; + +/** + * @author Luke Taylor + */ +public class Base64Tests { + + @Test + public void isBase64ReturnsTrueForValidBase64() { + new Base64(); // unused + + assertThat(Base64.isBase64(new byte[] { (byte) 'A', (byte) 'B', (byte) 'C', + (byte) 'D' })).isTrue(); + } + + @Test + public void isBase64ReturnsFalseForInvalidBase64() throws Exception { + // Include invalid '`' character + assertThat(Base64.isBase64(new byte[] { (byte) 'A', (byte) 'B', (byte) 'C', + (byte) '`' })).isFalse(); + } + + @Test(expected = NullPointerException.class) + public void isBase64RejectsNull() { + Base64.isBase64(null); + } + + @Test(expected = IllegalArgumentException.class) + public void isBase64RejectsInvalidLength() { + Base64.isBase64(new byte[] { (byte) 'A' }); + } +}