| /* Base64.java -- |
| Copyright (C) 2003, 2006 Free Software Foundation, Inc. |
| |
| This file is a part of GNU Classpath. |
| |
| GNU Classpath is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2 of the License, or (at |
| your option) any later version. |
| |
| GNU Classpath is distributed in the hope that it will be useful, but |
| WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU Classpath; if not, write to the Free Software |
| Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 |
| USA |
| |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. |
| |
| As a special exception, the copyright holders of this library give you |
| permission to link this library with independent modules to produce an |
| executable, regardless of the license terms of these independent |
| modules, and to copy and distribute the resulting executable under |
| terms of your choice, provided that you also meet, for each linked |
| independent module, the terms and conditions of the license of that |
| module. An independent module is a module which is not derived from |
| or based on this library. If you modify this library, you may extend |
| this exception to your version of the library, but you are not |
| obligated to do so. If you do not wish to do so, delete this |
| exception statement from your version. */ |
| |
| |
| package gnu.java.security.util; |
| |
| import gnu.java.security.Configuration; |
| |
| import java.io.UnsupportedEncodingException; |
| import java.util.logging.Logger; |
| |
| /** |
| * Most of this implementation is from Robert Harder's public domain Base64 |
| * code (version 1.4.1 available from <http://iharder.net/xmlizable>). |
| */ |
| public class Base64 |
| { |
| private static final Logger log = Logger.getLogger(Base64.class.getName()); |
| |
| /** Maximum line length (76) of Base64 output. */ |
| private static final int MAX_LINE_LENGTH = 76; |
| |
| /** The new line character (\n) as one byte. */ |
| private static final byte NEW_LINE = (byte) '\n'; |
| |
| /** The equals sign (=) as a byte. */ |
| private static final byte EQUALS_SIGN = (byte) '='; |
| |
| private static final byte WHITE_SPACE_ENC = -5; // white space in encoding |
| |
| private static final byte EQUALS_SIGN_ENC = -1; // equals sign in encoding |
| |
| /** The 64 valid Base64 values. */ |
| private static final byte[] 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 static final byte[] 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 // Decimal 123 - 126 |
| }; |
| |
| /** Trivial private ctor to enfore Singleton pattern. */ |
| private Base64() |
| { |
| super(); |
| } |
| |
| /** |
| * Encodes a byte array into Base64 notation. Equivalent to calling |
| * <code>encode(source, 0, source.length)</code>. |
| * |
| * @param src the data to convert. |
| */ |
| public static final String encode(final byte[] src) |
| { |
| return encode(src, 0, src.length, true); |
| } |
| |
| /** |
| * Encodes a byte array into Base64 notation. |
| * |
| * @param src the data to convert. |
| * @param off offset in array where conversion should begin. |
| * @param len length of data to convert. |
| * @param breakLines break lines at 80 characters or less. |
| */ |
| public static final String encode(final byte[] src, final int off, |
| final int len, final boolean breakLines) |
| { |
| final int len43 = len * 4 / 3; |
| final byte[] outBuff = new byte[len43 // Main 4:3 |
| + ((len % 3) > 0 ? 4 : 0) // Account for padding |
| + (breakLines ? (len43 / MAX_LINE_LENGTH) |
| : 0)]; // New lines |
| int d = 0; |
| int e = 0; |
| final int len2 = len - 2; |
| int lineLength = 0; |
| for (; d < len2; d += 3, e += 4) |
| { |
| encode3to4(src, d + off, 3, outBuff, e); |
| lineLength += 4; |
| if (breakLines && lineLength == MAX_LINE_LENGTH) |
| { |
| outBuff[e + 4] = NEW_LINE; |
| e++; |
| lineLength = 0; |
| } |
| } |
| if (d < len) // padding needed |
| { |
| encode3to4(src, d + off, len - d, outBuff, e); |
| e += 4; |
| } |
| return new String(outBuff, 0, e); |
| } |
| |
| /** |
| * Decodes data from Base64 notation. |
| * |
| * @param s the string to decode. |
| * @return the decoded data. |
| */ |
| public static final byte[] decode(final String s) |
| throws UnsupportedEncodingException |
| { |
| final byte[] bytes; |
| bytes = s.getBytes("US-ASCII"); |
| return decode(bytes, 0, bytes.length); |
| } |
| |
| /** |
| * Decodes Base64 content in byte array format and returns the decoded byte |
| * array. |
| * |
| * @param src the Base64 encoded data. |
| * @param off the offset of where to begin decoding. |
| * @param len the length of characters to decode. |
| * @return the decoded data. |
| * @throws IllegalArgumentException if <code>src</code> contains an illegal |
| * Base-64 character. |
| */ |
| public static byte[] decode(final byte[] src, final int off, final int len) |
| { |
| final int len34 = len * 3 / 4; |
| final byte[] outBuff = new byte[len34]; // Upper limit on size of output |
| int outBuffPosn = 0; |
| final byte[] b4 = new byte[4]; |
| int b4Posn = 0; |
| int i; |
| byte sbiCrop, sbiDecode; |
| for (i = off; i < off + len; i++) |
| { |
| sbiCrop = (byte) (src[i] & 0x7F); // Only the low seven bits |
| sbiDecode = DECODABET[sbiCrop]; |
| if (sbiDecode >= WHITE_SPACE_ENC) |
| { // White space, Equals sign or better |
| if (sbiDecode >= EQUALS_SIGN_ENC) |
| { |
| b4[b4Posn++] = sbiCrop; |
| if (b4Posn > 3) |
| { |
| outBuffPosn += decode4to3(b4, 0, outBuff, outBuffPosn); |
| b4Posn = 0; |
| // If that was the equals sign, break out of 'for' loop |
| if (sbiCrop == EQUALS_SIGN) |
| break; |
| } // end if: quartet built |
| } // end if: equals sign or better |
| } |
| throw new IllegalArgumentException("Illegal BASE-64 character at #" |
| + i + ": " + src[i] + "(decimal)"); |
| } |
| final byte[] result = new byte[outBuffPosn]; |
| System.arraycopy(outBuff, 0, result, 0, outBuffPosn); |
| return result; |
| } |
| |
| /** |
| * Encodes up to three bytes of the array <code>src</code> and writes the |
| * resulting four Base64 bytes to <code>dest</code>. The source and |
| * destination arrays can be manipulated anywhere along their length by |
| * specifying <code>sOffset</code> and <code>dOffset</code>. |
| * <p> |
| * This method does not check to make sure the arrays are large enough to |
| * accomodate <code>sOffset + 3</code> for the <code>src</code> array or |
| * <code>dOffset + 4</code> for the <code>dest</code> array. The actual |
| * number of significant bytes in the input array is given by |
| * <code>numBytes</code>. |
| * |
| * @param src the array to convert. |
| * @param sOffset the index where conversion begins. |
| * @param numBytes the number of significant bytes in your array. |
| * @param dest the array to hold the conversion. |
| * @param dOffset the index where output will be put. |
| * @return the <code>destination</code> array. |
| */ |
| private static final byte[] encode3to4(final byte[] src, final int sOffset, |
| final int numBytes, final byte[] dest, |
| final int dOffset) |
| { |
| // 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. |
| final int inBuff = (numBytes > 0 ? ((src[sOffset] << 24) >>> 8) : 0) |
| | (numBytes > 1 ? ((src[sOffset + 1] << 24) >>> 16) : 0) |
| | (numBytes > 2 ? ((src[sOffset + 2] << 24) >>> 24) : 0); |
| switch (numBytes) |
| { |
| case 3: |
| dest[dOffset ] = ALPHABET[(inBuff >>> 18)]; |
| dest[dOffset + 1] = ALPHABET[(inBuff >>> 12) & 0x3F]; |
| dest[dOffset + 2] = ALPHABET[(inBuff >>> 6) & 0x3F]; |
| dest[dOffset + 3] = ALPHABET[(inBuff) & 0x3F]; |
| break; |
| case 2: |
| dest[dOffset ] = ALPHABET[(inBuff >>> 18)]; |
| dest[dOffset + 1] = ALPHABET[(inBuff >>> 12) & 0x3F]; |
| dest[dOffset + 2] = ALPHABET[(inBuff >>> 6) & 0x3F]; |
| dest[dOffset + 3] = EQUALS_SIGN; |
| break; |
| case 1: |
| dest[dOffset ] = ALPHABET[(inBuff >>> 18)]; |
| dest[dOffset + 1] = ALPHABET[(inBuff >>> 12) & 0x3F]; |
| dest[dOffset + 2] = EQUALS_SIGN; |
| dest[dOffset + 3] = EQUALS_SIGN; |
| break; |
| } |
| return dest; |
| } |
| |
| /** |
| * Decodes four bytes from array <code>src</code> and writes the resulting |
| * bytes (up to three of them) to <code>dest</code>. |
| * <p> |
| * The source and destination arrays can be manipulated anywhere along their |
| * length by specifying <code>sOffset</code> and <code>dOffset</code>. |
| * <p> |
| * This method does not check to make sure your arrays are large enough to |
| * accomodate <code>sOffset + 4</code> for the <code>src</code> array or |
| * <code>dOffset + 3</code> for the <code>dest</code> array. This method |
| * returns the actual number of bytes that were converted from the Base64 |
| * encoding. |
| * |
| * @param src the array to convert. |
| * @param sOffset the index where conversion begins. |
| * @param dest the array to hold the conversion. |
| * @param dOffset the index where output will be put. |
| * @return the number of decoded bytes converted. |
| */ |
| private static final int decode4to3(final byte[] src, final int sOffset, |
| final byte[] dest, final int dOffset) |
| { |
| if (src[sOffset + 2] == EQUALS_SIGN) // Example: Dk== |
| { |
| final int outBuff = ((DECODABET[src[sOffset ]] & 0xFF) << 18) |
| | ((DECODABET[src[sOffset + 1]] & 0xFF) << 12); |
| dest[dOffset] = (byte)(outBuff >>> 16); |
| return 1; |
| } |
| if (src[sOffset + 3] == EQUALS_SIGN) // Example: DkL= |
| { |
| final int outBuff = ((DECODABET[src[sOffset ]] & 0xFF) << 18) |
| | ((DECODABET[src[sOffset + 1]] & 0xFF) << 12) |
| | ((DECODABET[src[sOffset + 2]] & 0xFF) << 6); |
| dest[dOffset ] = (byte)(outBuff >>> 16); |
| dest[dOffset + 1] = (byte)(outBuff >>> 8); |
| return 2; |
| } |
| try // Example: DkLE |
| { |
| final int outBuff = ((DECODABET[src[sOffset ]] & 0xFF) << 18) |
| | ((DECODABET[src[sOffset + 1]] & 0xFF) << 12) |
| | ((DECODABET[src[sOffset + 2]] & 0xFF) << 6) |
| | ((DECODABET[src[sOffset + 3]] & 0xFF)); |
| dest[dOffset ] = (byte)(outBuff >> 16); |
| dest[dOffset + 1] = (byte)(outBuff >> 8); |
| dest[dOffset + 2] = (byte) outBuff; |
| return 3; |
| } |
| catch (Exception x) |
| { |
| if (Configuration.DEBUG) |
| { |
| log.fine("" + src[sOffset ] + ": " + (DECODABET[src[sOffset ]])); |
| log.fine("" + src[sOffset + 1] + ": " + (DECODABET[src[sOffset + 1]])); |
| log.fine("" + src[sOffset + 2] + ": " + (DECODABET[src[sOffset + 2]])); |
| log.fine("" + src[sOffset + 3] + ": " + (DECODABET[src[sOffset + 3]])); |
| } |
| return -1; |
| } |
| } |
| } |
