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Diffstat (limited to 'libjava/classpath/gnu/java/security/util/Base64.java')
| -rw-r--r-- | libjava/classpath/gnu/java/security/util/Base64.java | 396 |
1 files changed, 396 insertions, 0 deletions
diff --git a/libjava/classpath/gnu/java/security/util/Base64.java b/libjava/classpath/gnu/java/security/util/Base64.java new file mode 100644 index 00000000000..f9998c38f48 --- /dev/null +++ b/libjava/classpath/gnu/java/security/util/Base64.java @@ -0,0 +1,396 @@ +/* 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 java.io.PrintWriter; +import java.io.UnsupportedEncodingException; + +/** + * 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 +{ + + // Debugging methods and variables + // ------------------------------------------------------------------------- + + private static final String NAME = "Base64"; + + private static final boolean DEBUG = true; + + private static final int debuglevel = 9; + + private static final PrintWriter err = new PrintWriter(System.out, true); + + private static void debug(String s) + { + err.println(">>> " + NAME + ": " + s); + } + + // Constants and variables + // ------------------------------------------------------------------------- + + /** 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 + }; + + // Constructor(s) + // ------------------------------------------------------------------------- + + /** Trivial private ctor to enfore Singleton pattern. */ + private Base64() + { + super(); + } + + // Class methods + // ------------------------------------------------------------------------- + + /** + * 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 + } + else + { + 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; + } + + /** + * <p>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> + * + * <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>.</p> + * + * @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; + } + + /** + * <p>Decodes four bytes from array <code>src</code> and writes the + * resulting bytes (up to three of them) to <code>dest</code>.</p> + * + * <p>The source and destination arrays can be manipulated anywhere along + * their length by specifying <code>sOffset</code> and <code>dOffset</code>. + * </p> + * + * <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.</p> + * + * @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 (DEBUG && debuglevel > 8) + { + debug("" + src[sOffset] + ": " + (DECODABET[src[sOffset]])); + debug("" + src[sOffset + 1] + ": " + (DECODABET[src[sOffset + 1]])); + debug("" + src[sOffset + 2] + ": " + (DECODABET[src[sOffset + 2]])); + debug("" + src[sOffset + 3] + ": " + (DECODABET[src[sOffset + 3]])); + } + return -1; + } + } +} |