| /* |
| * Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code 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 |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package java.util; |
| |
| import java.io.FilterOutputStream; |
| import java.io.InputStream; |
| import java.io.IOException; |
| import java.io.OutputStream; |
| import java.nio.ByteBuffer; |
| import java.nio.charset.StandardCharsets; |
| |
| /** |
| * This class consists exclusively of static methods for obtaining |
| * encoders and decoders for the Base64 encoding scheme. The |
| * implementation of this class supports the following types of Base64 |
| * as specified in |
| * <a href="http://www.ietf.org/rfc/rfc4648.txt">RFC 4648</a> and |
| * <a href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045</a>. |
| * |
| * <ul> |
| * <li><a name="basic"><b>Basic</b></a> |
| * <p> Uses "The Base64 Alphabet" as specified in Table 1 of |
| * RFC 4648 and RFC 2045 for encoding and decoding operation. |
| * The encoder does not add any line feed (line separator) |
| * character. The decoder rejects data that contains characters |
| * outside the base64 alphabet.</p></li> |
| * |
| * <li><a name="url"><b>URL and Filename safe</b></a> |
| * <p> Uses the "URL and Filename safe Base64 Alphabet" as specified |
| * in Table 2 of RFC 4648 for encoding and decoding. The |
| * encoder does not add any line feed (line separator) character. |
| * The decoder rejects data that contains characters outside the |
| * base64 alphabet.</p></li> |
| * |
| * <li><a name="mime"><b>MIME</b></a> |
| * <p> Uses the "The Base64 Alphabet" as specified in Table 1 of |
| * RFC 2045 for encoding and decoding operation. The encoded output |
| * must be represented in lines of no more than 76 characters each |
| * and uses a carriage return {@code '\r'} followed immediately by |
| * a linefeed {@code '\n'} as the line separator. No line separator |
| * is added to the end of the encoded output. All line separators |
| * or other characters not found in the base64 alphabet table are |
| * ignored in decoding operation.</p></li> |
| * </ul> |
| * |
| * <p> Unless otherwise noted, passing a {@code null} argument to a |
| * method of this class will cause a {@link java.lang.NullPointerException |
| * NullPointerException} to be thrown. |
| * |
| * @author Xueming Shen |
| * @since 1.8 |
| */ |
| |
| public class Base64 { |
| |
| private Base64() {} |
| |
| /** |
| * Returns a {@link Encoder} that encodes using the |
| * <a href="#basic">Basic</a> type base64 encoding scheme. |
| * |
| * @return A Base64 encoder. |
| */ |
| public static Encoder getEncoder() { |
| return Encoder.RFC4648; |
| } |
| |
| /** |
| * Returns a {@link Encoder} that encodes using the |
| * <a href="#url">URL and Filename safe</a> type base64 |
| * encoding scheme. |
| * |
| * @return A Base64 encoder. |
| */ |
| public static Encoder getUrlEncoder() { |
| return Encoder.RFC4648_URLSAFE; |
| } |
| |
| /** |
| * Returns a {@link Encoder} that encodes using the |
| * <a href="#mime">MIME</a> type base64 encoding scheme. |
| * |
| * @return A Base64 encoder. |
| */ |
| public static Encoder getMimeEncoder() { |
| return Encoder.RFC2045; |
| } |
| |
| /** |
| * Returns a {@link Encoder} that encodes using the |
| * <a href="#mime">MIME</a> type base64 encoding scheme |
| * with specified line length and line separators. |
| * |
| * @param lineLength |
| * the length of each output line (rounded down to nearest multiple |
| * of 4). If {@code lineLength <= 0} the output will not be separated |
| * in lines |
| * @param lineSeparator |
| * the line separator for each output line |
| * |
| * @return A Base64 encoder. |
| * |
| * @throws IllegalArgumentException if {@code lineSeparator} includes any |
| * character of "The Base64 Alphabet" as specified in Table 1 of |
| * RFC 2045. |
| */ |
| public static Encoder getMimeEncoder(int lineLength, byte[] lineSeparator) { |
| Objects.requireNonNull(lineSeparator); |
| int[] base64 = Decoder.fromBase64; |
| for (byte b : lineSeparator) { |
| if (base64[b & 0xff] != -1) |
| throw new IllegalArgumentException( |
| "Illegal base64 line separator character 0x" + Integer.toString(b, 16)); |
| } |
| if (lineLength <= 0) { |
| return Encoder.RFC4648; |
| } |
| return new Encoder(false, lineSeparator, lineLength >> 2 << 2, true); |
| } |
| |
| /** |
| * Returns a {@link Decoder} that decodes using the |
| * <a href="#basic">Basic</a> type base64 encoding scheme. |
| * |
| * @return A Base64 decoder. |
| */ |
| public static Decoder getDecoder() { |
| return Decoder.RFC4648; |
| } |
| |
| /** |
| * Returns a {@link Decoder} that decodes using the |
| * <a href="#url">URL and Filename safe</a> type base64 |
| * encoding scheme. |
| * |
| * @return A Base64 decoder. |
| */ |
| public static Decoder getUrlDecoder() { |
| return Decoder.RFC4648_URLSAFE; |
| } |
| |
| /** |
| * Returns a {@link Decoder} that decodes using the |
| * <a href="#mime">MIME</a> type base64 decoding scheme. |
| * |
| * @return A Base64 decoder. |
| */ |
| public static Decoder getMimeDecoder() { |
| return Decoder.RFC2045; |
| } |
| |
| /** |
| * This class implements an encoder for encoding byte data using |
| * the Base64 encoding scheme as specified in RFC 4648 and RFC 2045. |
| * |
| * <p> Instances of {@link Encoder} class are safe for use by |
| * multiple concurrent threads. |
| * |
| * <p> Unless otherwise noted, passing a {@code null} argument to |
| * a method of this class will cause a |
| * {@link java.lang.NullPointerException NullPointerException} to |
| * be thrown. |
| * |
| * @see Decoder |
| * @since 1.8 |
| */ |
| public static class Encoder { |
| |
| private final byte[] newline; |
| private final int linemax; |
| private final boolean isURL; |
| private final boolean doPadding; |
| |
| private Encoder(boolean isURL, byte[] newline, int linemax, boolean doPadding) { |
| this.isURL = isURL; |
| this.newline = newline; |
| this.linemax = linemax; |
| this.doPadding = doPadding; |
| } |
| |
| /** |
| * This array is a lookup table that translates 6-bit positive integer |
| * index values into their "Base64 Alphabet" equivalents as specified |
| * in "Table 1: The Base64 Alphabet" of RFC 2045 (and RFC 4648). |
| */ |
| private static final char[] toBase64 = { |
| 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', |
| 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', |
| 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', |
| 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', |
| '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/' |
| }; |
| |
| /** |
| * It's the lookup table for "URL and Filename safe Base64" as specified |
| * in Table 2 of the RFC 4648, with the '+' and '/' changed to '-' and |
| * '_'. This table is used when BASE64_URL is specified. |
| */ |
| private static final char[] toBase64URL = { |
| 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', |
| 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', |
| 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', |
| 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', |
| '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '-', '_' |
| }; |
| |
| private static final int MIMELINEMAX = 76; |
| private static final byte[] CRLF = new byte[] {'\r', '\n'}; |
| |
| static final Encoder RFC4648 = new Encoder(false, null, -1, true); |
| static final Encoder RFC4648_URLSAFE = new Encoder(true, null, -1, true); |
| static final Encoder RFC2045 = new Encoder(false, CRLF, MIMELINEMAX, true); |
| |
| private final int outLength(int srclen) { |
| int len = 0; |
| if (doPadding) { |
| len = 4 * ((srclen + 2) / 3); |
| } else { |
| int n = srclen % 3; |
| len = 4 * (srclen / 3) + (n == 0 ? 0 : n + 1); |
| } |
| if (linemax > 0) // line separators |
| len += (len - 1) / linemax * newline.length; |
| return len; |
| } |
| |
| /** |
| * Encodes all bytes from the specified byte array into a newly-allocated |
| * byte array using the {@link Base64} encoding scheme. The returned byte |
| * array is of the length of the resulting bytes. |
| * |
| * @param src |
| * the byte array to encode |
| * @return A newly-allocated byte array containing the resulting |
| * encoded bytes. |
| */ |
| public byte[] encode(byte[] src) { |
| int len = outLength(src.length); // dst array size |
| byte[] dst = new byte[len]; |
| int ret = encode0(src, 0, src.length, dst); |
| if (ret != dst.length) |
| return Arrays.copyOf(dst, ret); |
| return dst; |
| } |
| |
| /** |
| * Encodes all bytes from the specified byte array using the |
| * {@link Base64} encoding scheme, writing the resulting bytes to the |
| * given output byte array, starting at offset 0. |
| * |
| * <p> It is the responsibility of the invoker of this method to make |
| * sure the output byte array {@code dst} has enough space for encoding |
| * all bytes from the input byte array. No bytes will be written to the |
| * output byte array if the output byte array is not big enough. |
| * |
| * @param src |
| * the byte array to encode |
| * @param dst |
| * the output byte array |
| * @return The number of bytes written to the output byte array |
| * |
| * @throws IllegalArgumentException if {@code dst} does not have enough |
| * space for encoding all input bytes. |
| */ |
| public int encode(byte[] src, byte[] dst) { |
| int len = outLength(src.length); // dst array size |
| if (dst.length < len) |
| throw new IllegalArgumentException( |
| "Output byte array is too small for encoding all input bytes"); |
| return encode0(src, 0, src.length, dst); |
| } |
| |
| /** |
| * Encodes the specified byte array into a String using the {@link Base64} |
| * encoding scheme. |
| * |
| * <p> This method first encodes all input bytes into a base64 encoded |
| * byte array and then constructs a new String by using the encoded byte |
| * array and the {@link java.nio.charset.StandardCharsets#ISO_8859_1 |
| * ISO-8859-1} charset. |
| * |
| * <p> In other words, an invocation of this method has exactly the same |
| * effect as invoking |
| * {@code new String(encode(src), StandardCharsets.ISO_8859_1)}. |
| * |
| * @param src |
| * the byte array to encode |
| * @return A String containing the resulting Base64 encoded characters |
| */ |
| @SuppressWarnings("deprecation") |
| public String encodeToString(byte[] src) { |
| byte[] encoded = encode(src); |
| return new String(encoded, 0, 0, encoded.length); |
| } |
| |
| /** |
| * Encodes all remaining bytes from the specified byte buffer into |
| * a newly-allocated ByteBuffer using the {@link Base64} encoding |
| * scheme. |
| * |
| * Upon return, the source buffer's position will be updated to |
| * its limit; its limit will not have been changed. The returned |
| * output buffer's position will be zero and its limit will be the |
| * number of resulting encoded bytes. |
| * |
| * @param buffer |
| * the source ByteBuffer to encode |
| * @return A newly-allocated byte buffer containing the encoded bytes. |
| */ |
| public ByteBuffer encode(ByteBuffer buffer) { |
| int len = outLength(buffer.remaining()); |
| byte[] dst = new byte[len]; |
| int ret = 0; |
| if (buffer.hasArray()) { |
| ret = encode0(buffer.array(), |
| buffer.arrayOffset() + buffer.position(), |
| buffer.arrayOffset() + buffer.limit(), |
| dst); |
| buffer.position(buffer.limit()); |
| } else { |
| byte[] src = new byte[buffer.remaining()]; |
| buffer.get(src); |
| ret = encode0(src, 0, src.length, dst); |
| } |
| if (ret != dst.length) |
| dst = Arrays.copyOf(dst, ret); |
| return ByteBuffer.wrap(dst); |
| } |
| |
| /** |
| * Wraps an output stream for encoding byte data using the {@link Base64} |
| * encoding scheme. |
| * |
| * <p> It is recommended to promptly close the returned output stream after |
| * use, during which it will flush all possible leftover bytes to the underlying |
| * output stream. Closing the returned output stream will close the underlying |
| * output stream. |
| * |
| * @param os |
| * the output stream. |
| * @return the output stream for encoding the byte data into the |
| * specified Base64 encoded format |
| */ |
| public OutputStream wrap(OutputStream os) { |
| Objects.requireNonNull(os); |
| return new EncOutputStream(os, isURL ? toBase64URL : toBase64, |
| newline, linemax, doPadding); |
| } |
| |
| /** |
| * Returns an encoder instance that encodes equivalently to this one, |
| * but without adding any padding character at the end of the encoded |
| * byte data. |
| * |
| * <p> The encoding scheme of this encoder instance is unaffected by |
| * this invocation. The returned encoder instance should be used for |
| * non-padding encoding operation. |
| * |
| * @return an equivalent encoder that encodes without adding any |
| * padding character at the end |
| */ |
| public Encoder withoutPadding() { |
| if (!doPadding) |
| return this; |
| return new Encoder(isURL, newline, linemax, false); |
| } |
| |
| private int encode0(byte[] src, int off, int end, byte[] dst) { |
| char[] base64 = isURL ? toBase64URL : toBase64; |
| int sp = off; |
| int slen = (end - off) / 3 * 3; |
| int sl = off + slen; |
| if (linemax > 0 && slen > linemax / 4 * 3) |
| slen = linemax / 4 * 3; |
| int dp = 0; |
| while (sp < sl) { |
| int sl0 = Math.min(sp + slen, sl); |
| for (int sp0 = sp, dp0 = dp ; sp0 < sl0; ) { |
| int bits = (src[sp0++] & 0xff) << 16 | |
| (src[sp0++] & 0xff) << 8 | |
| (src[sp0++] & 0xff); |
| dst[dp0++] = (byte)base64[(bits >>> 18) & 0x3f]; |
| dst[dp0++] = (byte)base64[(bits >>> 12) & 0x3f]; |
| dst[dp0++] = (byte)base64[(bits >>> 6) & 0x3f]; |
| dst[dp0++] = (byte)base64[bits & 0x3f]; |
| } |
| int dlen = (sl0 - sp) / 3 * 4; |
| dp += dlen; |
| sp = sl0; |
| if (dlen == linemax && sp < end) { |
| for (byte b : newline){ |
| dst[dp++] = b; |
| } |
| } |
| } |
| if (sp < end) { // 1 or 2 leftover bytes |
| int b0 = src[sp++] & 0xff; |
| dst[dp++] = (byte)base64[b0 >> 2]; |
| if (sp == end) { |
| dst[dp++] = (byte)base64[(b0 << 4) & 0x3f]; |
| if (doPadding) { |
| dst[dp++] = '='; |
| dst[dp++] = '='; |
| } |
| } else { |
| int b1 = src[sp++] & 0xff; |
| dst[dp++] = (byte)base64[(b0 << 4) & 0x3f | (b1 >> 4)]; |
| dst[dp++] = (byte)base64[(b1 << 2) & 0x3f]; |
| if (doPadding) { |
| dst[dp++] = '='; |
| } |
| } |
| } |
| return dp; |
| } |
| } |
| |
| /** |
| * This class implements a decoder for decoding byte data using the |
| * Base64 encoding scheme as specified in RFC 4648 and RFC 2045. |
| * |
| * <p> The Base64 padding character {@code '='} is accepted and |
| * interpreted as the end of the encoded byte data, but is not |
| * required. So if the final unit of the encoded byte data only has |
| * two or three Base64 characters (without the corresponding padding |
| * character(s) padded), they are decoded as if followed by padding |
| * character(s). If there is a padding character present in the |
| * final unit, the correct number of padding character(s) must be |
| * present, otherwise {@code IllegalArgumentException} ( |
| * {@code IOException} when reading from a Base64 stream) is thrown |
| * during decoding. |
| * |
| * <p> Instances of {@link Decoder} class are safe for use by |
| * multiple concurrent threads. |
| * |
| * <p> Unless otherwise noted, passing a {@code null} argument to |
| * a method of this class will cause a |
| * {@link java.lang.NullPointerException NullPointerException} to |
| * be thrown. |
| * |
| * @see Encoder |
| * @since 1.8 |
| */ |
| public static class Decoder { |
| |
| private final boolean isURL; |
| private final boolean isMIME; |
| |
| private Decoder(boolean isURL, boolean isMIME) { |
| this.isURL = isURL; |
| this.isMIME = isMIME; |
| } |
| |
| /** |
| * Lookup table for decoding unicode characters drawn from the |
| * "Base64 Alphabet" (as specified in Table 1 of RFC 2045) into |
| * their 6-bit positive integer equivalents. Characters that |
| * are not in the Base64 alphabet but fall within the bounds of |
| * the array are encoded to -1. |
| * |
| */ |
| private static final int[] fromBase64 = new int[256]; |
| static { |
| Arrays.fill(fromBase64, -1); |
| for (int i = 0; i < Encoder.toBase64.length; i++) |
| fromBase64[Encoder.toBase64[i]] = i; |
| fromBase64['='] = -2; |
| } |
| |
| /** |
| * Lookup table for decoding "URL and Filename safe Base64 Alphabet" |
| * as specified in Table2 of the RFC 4648. |
| */ |
| private static final int[] fromBase64URL = new int[256]; |
| |
| static { |
| Arrays.fill(fromBase64URL, -1); |
| for (int i = 0; i < Encoder.toBase64URL.length; i++) |
| fromBase64URL[Encoder.toBase64URL[i]] = i; |
| fromBase64URL['='] = -2; |
| } |
| |
| static final Decoder RFC4648 = new Decoder(false, false); |
| static final Decoder RFC4648_URLSAFE = new Decoder(true, false); |
| static final Decoder RFC2045 = new Decoder(false, true); |
| |
| /** |
| * Decodes all bytes from the input byte array using the {@link Base64} |
| * encoding scheme, writing the results into a newly-allocated output |
| * byte array. The returned byte array is of the length of the resulting |
| * bytes. |
| * |
| * @param src |
| * the byte array to decode |
| * |
| * @return A newly-allocated byte array containing the decoded bytes. |
| * |
| * @throws IllegalArgumentException |
| * if {@code src} is not in valid Base64 scheme |
| */ |
| public byte[] decode(byte[] src) { |
| byte[] dst = new byte[outLength(src, 0, src.length)]; |
| int ret = decode0(src, 0, src.length, dst); |
| if (ret != dst.length) { |
| dst = Arrays.copyOf(dst, ret); |
| } |
| return dst; |
| } |
| |
| /** |
| * Decodes a Base64 encoded String into a newly-allocated byte array |
| * using the {@link Base64} encoding scheme. |
| * |
| * <p> An invocation of this method has exactly the same effect as invoking |
| * {@code decode(src.getBytes(StandardCharsets.ISO_8859_1))} |
| * |
| * @param src |
| * the string to decode |
| * |
| * @return A newly-allocated byte array containing the decoded bytes. |
| * |
| * @throws IllegalArgumentException |
| * if {@code src} is not in valid Base64 scheme |
| */ |
| public byte[] decode(String src) { |
| return decode(src.getBytes(StandardCharsets.ISO_8859_1)); |
| } |
| |
| /** |
| * Decodes all bytes from the input byte array using the {@link Base64} |
| * encoding scheme, writing the results into the given output byte array, |
| * starting at offset 0. |
| * |
| * <p> It is the responsibility of the invoker of this method to make |
| * sure the output byte array {@code dst} has enough space for decoding |
| * all bytes from the input byte array. No bytes will be be written to |
| * the output byte array if the output byte array is not big enough. |
| * |
| * <p> If the input byte array is not in valid Base64 encoding scheme |
| * then some bytes may have been written to the output byte array before |
| * IllegalargumentException is thrown. |
| * |
| * @param src |
| * the byte array to decode |
| * @param dst |
| * the output byte array |
| * |
| * @return The number of bytes written to the output byte array |
| * |
| * @throws IllegalArgumentException |
| * if {@code src} is not in valid Base64 scheme, or {@code dst} |
| * does not have enough space for decoding all input bytes. |
| */ |
| public int decode(byte[] src, byte[] dst) { |
| int len = outLength(src, 0, src.length); |
| if (dst.length < len) |
| throw new IllegalArgumentException( |
| "Output byte array is too small for decoding all input bytes"); |
| return decode0(src, 0, src.length, dst); |
| } |
| |
| /** |
| * Decodes all bytes from the input byte buffer using the {@link Base64} |
| * encoding scheme, writing the results into a newly-allocated ByteBuffer. |
| * |
| * <p> Upon return, the source buffer's position will be updated to |
| * its limit; its limit will not have been changed. The returned |
| * output buffer's position will be zero and its limit will be the |
| * number of resulting decoded bytes |
| * |
| * <p> {@code IllegalArgumentException} is thrown if the input buffer |
| * is not in valid Base64 encoding scheme. The position of the input |
| * buffer will not be advanced in this case. |
| * |
| * @param buffer |
| * the ByteBuffer to decode |
| * |
| * @return A newly-allocated byte buffer containing the decoded bytes |
| * |
| * @throws IllegalArgumentException |
| * if {@code src} is not in valid Base64 scheme. |
| */ |
| public ByteBuffer decode(ByteBuffer buffer) { |
| int pos0 = buffer.position(); |
| try { |
| byte[] src; |
| int sp, sl; |
| if (buffer.hasArray()) { |
| src = buffer.array(); |
| sp = buffer.arrayOffset() + buffer.position(); |
| sl = buffer.arrayOffset() + buffer.limit(); |
| buffer.position(buffer.limit()); |
| } else { |
| src = new byte[buffer.remaining()]; |
| buffer.get(src); |
| sp = 0; |
| sl = src.length; |
| } |
| byte[] dst = new byte[outLength(src, sp, sl)]; |
| return ByteBuffer.wrap(dst, 0, decode0(src, sp, sl, dst)); |
| } catch (IllegalArgumentException iae) { |
| buffer.position(pos0); |
| throw iae; |
| } |
| } |
| |
| /** |
| * Returns an input stream for decoding {@link Base64} encoded byte stream. |
| * |
| * <p> The {@code read} methods of the returned {@code InputStream} will |
| * throw {@code IOException} when reading bytes that cannot be decoded. |
| * |
| * <p> Closing the returned input stream will close the underlying |
| * input stream. |
| * |
| * @param is |
| * the input stream |
| * |
| * @return the input stream for decoding the specified Base64 encoded |
| * byte stream |
| */ |
| public InputStream wrap(InputStream is) { |
| Objects.requireNonNull(is); |
| return new DecInputStream(is, isURL ? fromBase64URL : fromBase64, isMIME); |
| } |
| |
| private int outLength(byte[] src, int sp, int sl) { |
| int[] base64 = isURL ? fromBase64URL : fromBase64; |
| int paddings = 0; |
| int len = sl - sp; |
| if (len == 0) |
| return 0; |
| if (len < 2) { |
| if (isMIME && base64[0] == -1) |
| return 0; |
| throw new IllegalArgumentException( |
| "Input byte[] should at least have 2 bytes for base64 bytes"); |
| } |
| if (isMIME) { |
| // scan all bytes to fill out all non-alphabet. a performance |
| // trade-off of pre-scan or Arrays.copyOf |
| int n = 0; |
| while (sp < sl) { |
| int b = src[sp++] & 0xff; |
| if (b == '=') { |
| len -= (sl - sp + 1); |
| break; |
| } |
| if ((b = base64[b]) == -1) |
| n++; |
| } |
| len -= n; |
| } else { |
| if (src[sl - 1] == '=') { |
| paddings++; |
| if (src[sl - 2] == '=') |
| paddings++; |
| } |
| } |
| if (paddings == 0 && (len & 0x3) != 0) |
| paddings = 4 - (len & 0x3); |
| return 3 * ((len + 3) / 4) - paddings; |
| } |
| |
| private int decode0(byte[] src, int sp, int sl, byte[] dst) { |
| int[] base64 = isURL ? fromBase64URL : fromBase64; |
| int dp = 0; |
| int bits = 0; |
| int shiftto = 18; // pos of first byte of 4-byte atom |
| while (sp < sl) { |
| int b = src[sp++] & 0xff; |
| if ((b = base64[b]) < 0) { |
| if (b == -2) { // padding byte '=' |
| // = shiftto==18 unnecessary padding |
| // x= shiftto==12 a dangling single x |
| // x to be handled together with non-padding case |
| // xx= shiftto==6&&sp==sl missing last = |
| // xx=y shiftto==6 last is not = |
| if (shiftto == 6 && (sp == sl || src[sp++] != '=') || |
| shiftto == 18) { |
| throw new IllegalArgumentException( |
| "Input byte array has wrong 4-byte ending unit"); |
| } |
| break; |
| } |
| if (isMIME) // skip if for rfc2045 |
| continue; |
| else |
| throw new IllegalArgumentException( |
| "Illegal base64 character " + |
| Integer.toString(src[sp - 1], 16)); |
| } |
| bits |= (b << shiftto); |
| shiftto -= 6; |
| if (shiftto < 0) { |
| dst[dp++] = (byte)(bits >> 16); |
| dst[dp++] = (byte)(bits >> 8); |
| dst[dp++] = (byte)(bits); |
| shiftto = 18; |
| bits = 0; |
| } |
| } |
| // reached end of byte array or hit padding '=' characters. |
| if (shiftto == 6) { |
| dst[dp++] = (byte)(bits >> 16); |
| } else if (shiftto == 0) { |
| dst[dp++] = (byte)(bits >> 16); |
| dst[dp++] = (byte)(bits >> 8); |
| } else if (shiftto == 12) { |
| // dangling single "x", incorrectly encoded. |
| throw new IllegalArgumentException( |
| "Last unit does not have enough valid bits"); |
| } |
| // anything left is invalid, if is not MIME. |
| // if MIME, ignore all non-base64 character |
| while (sp < sl) { |
| if (isMIME && base64[src[sp++]] < 0) |
| continue; |
| throw new IllegalArgumentException( |
| "Input byte array has incorrect ending byte at " + sp); |
| } |
| return dp; |
| } |
| } |
| |
| /* |
| * An output stream for encoding bytes into the Base64. |
| */ |
| private static class EncOutputStream extends FilterOutputStream { |
| |
| private int leftover = 0; |
| private int b0, b1, b2; |
| private boolean closed = false; |
| |
| private final char[] base64; // byte->base64 mapping |
| private final byte[] newline; // line separator, if needed |
| private final int linemax; |
| private final boolean doPadding;// whether or not to pad |
| private int linepos = 0; |
| |
| EncOutputStream(OutputStream os, char[] base64, |
| byte[] newline, int linemax, boolean doPadding) { |
| super(os); |
| this.base64 = base64; |
| this.newline = newline; |
| this.linemax = linemax; |
| this.doPadding = doPadding; |
| } |
| |
| @Override |
| public void write(int b) throws IOException { |
| byte[] buf = new byte[1]; |
| buf[0] = (byte)(b & 0xff); |
| write(buf, 0, 1); |
| } |
| |
| private void checkNewline() throws IOException { |
| if (linepos == linemax) { |
| out.write(newline); |
| linepos = 0; |
| } |
| } |
| |
| @Override |
| public void write(byte[] b, int off, int len) throws IOException { |
| if (closed) |
| throw new IOException("Stream is closed"); |
| if (off < 0 || len < 0 || off + len > b.length) |
| throw new ArrayIndexOutOfBoundsException(); |
| if (len == 0) |
| return; |
| if (leftover != 0) { |
| if (leftover == 1) { |
| b1 = b[off++] & 0xff; |
| len--; |
| if (len == 0) { |
| leftover++; |
| return; |
| } |
| } |
| b2 = b[off++] & 0xff; |
| len--; |
| checkNewline(); |
| out.write(base64[b0 >> 2]); |
| out.write(base64[(b0 << 4) & 0x3f | (b1 >> 4)]); |
| out.write(base64[(b1 << 2) & 0x3f | (b2 >> 6)]); |
| out.write(base64[b2 & 0x3f]); |
| linepos += 4; |
| } |
| int nBits24 = len / 3; |
| leftover = len - (nBits24 * 3); |
| while (nBits24-- > 0) { |
| checkNewline(); |
| int bits = (b[off++] & 0xff) << 16 | |
| (b[off++] & 0xff) << 8 | |
| (b[off++] & 0xff); |
| out.write(base64[(bits >>> 18) & 0x3f]); |
| out.write(base64[(bits >>> 12) & 0x3f]); |
| out.write(base64[(bits >>> 6) & 0x3f]); |
| out.write(base64[bits & 0x3f]); |
| linepos += 4; |
| } |
| if (leftover == 1) { |
| b0 = b[off++] & 0xff; |
| } else if (leftover == 2) { |
| b0 = b[off++] & 0xff; |
| b1 = b[off++] & 0xff; |
| } |
| } |
| |
| @Override |
| public void close() throws IOException { |
| if (!closed) { |
| closed = true; |
| if (leftover == 1) { |
| checkNewline(); |
| out.write(base64[b0 >> 2]); |
| out.write(base64[(b0 << 4) & 0x3f]); |
| if (doPadding) { |
| out.write('='); |
| out.write('='); |
| } |
| } else if (leftover == 2) { |
| checkNewline(); |
| out.write(base64[b0 >> 2]); |
| out.write(base64[(b0 << 4) & 0x3f | (b1 >> 4)]); |
| out.write(base64[(b1 << 2) & 0x3f]); |
| if (doPadding) { |
| out.write('='); |
| } |
| } |
| leftover = 0; |
| out.close(); |
| } |
| } |
| } |
| |
| /* |
| * An input stream for decoding Base64 bytes |
| */ |
| private static class DecInputStream extends InputStream { |
| |
| private final InputStream is; |
| private final boolean isMIME; |
| private final int[] base64; // base64 -> byte mapping |
| private int bits = 0; // 24-bit buffer for decoding |
| private int nextin = 18; // next available "off" in "bits" for input; |
| // -> 18, 12, 6, 0 |
| private int nextout = -8; // next available "off" in "bits" for output; |
| // -> 8, 0, -8 (no byte for output) |
| private boolean eof = false; |
| private boolean closed = false; |
| |
| DecInputStream(InputStream is, int[] base64, boolean isMIME) { |
| this.is = is; |
| this.base64 = base64; |
| this.isMIME = isMIME; |
| } |
| |
| private byte[] sbBuf = new byte[1]; |
| |
| @Override |
| public int read() throws IOException { |
| return read(sbBuf, 0, 1) == -1 ? -1 : sbBuf[0] & 0xff; |
| } |
| |
| @Override |
| public int read(byte[] b, int off, int len) throws IOException { |
| if (closed) |
| throw new IOException("Stream is closed"); |
| if (eof && nextout < 0) // eof and no leftover |
| return -1; |
| if (off < 0 || len < 0 || len > b.length - off) |
| throw new IndexOutOfBoundsException(); |
| int oldOff = off; |
| if (nextout >= 0) { // leftover output byte(s) in bits buf |
| do { |
| if (len == 0) |
| return off - oldOff; |
| b[off++] = (byte)(bits >> nextout); |
| len--; |
| nextout -= 8; |
| } while (nextout >= 0); |
| bits = 0; |
| } |
| while (len > 0) { |
| int v = is.read(); |
| if (v == -1) { |
| eof = true; |
| if (nextin != 18) { |
| if (nextin == 12) |
| throw new IOException("Base64 stream has one un-decoded dangling byte."); |
| // treat ending xx/xxx without padding character legal. |
| // same logic as v == '=' below |
| b[off++] = (byte)(bits >> (16)); |
| len--; |
| if (nextin == 0) { // only one padding byte |
| if (len == 0) { // no enough output space |
| bits >>= 8; // shift to lowest byte |
| nextout = 0; |
| } else { |
| b[off++] = (byte) (bits >> 8); |
| } |
| } |
| } |
| if (off == oldOff) |
| return -1; |
| else |
| return off - oldOff; |
| } |
| if (v == '=') { // padding byte(s) |
| // = shiftto==18 unnecessary padding |
| // x= shiftto==12 dangling x, invalid unit |
| // xx= shiftto==6 && missing last '=' |
| // xx=y or last is not '=' |
| if (nextin == 18 || nextin == 12 || |
| nextin == 6 && is.read() != '=') { |
| throw new IOException("Illegal base64 ending sequence:" + nextin); |
| } |
| b[off++] = (byte)(bits >> (16)); |
| len--; |
| if (nextin == 0) { // only one padding byte |
| if (len == 0) { // no enough output space |
| bits >>= 8; // shift to lowest byte |
| nextout = 0; |
| } else { |
| b[off++] = (byte) (bits >> 8); |
| } |
| } |
| eof = true; |
| break; |
| } |
| if ((v = base64[v]) == -1) { |
| if (isMIME) // skip if for rfc2045 |
| continue; |
| else |
| throw new IOException("Illegal base64 character " + |
| Integer.toString(v, 16)); |
| } |
| bits |= (v << nextin); |
| if (nextin == 0) { |
| nextin = 18; // clear for next |
| nextout = 16; |
| while (nextout >= 0) { |
| b[off++] = (byte)(bits >> nextout); |
| len--; |
| nextout -= 8; |
| if (len == 0 && nextout >= 0) { // don't clean "bits" |
| return off - oldOff; |
| } |
| } |
| bits = 0; |
| } else { |
| nextin -= 6; |
| } |
| } |
| return off - oldOff; |
| } |
| |
| @Override |
| public int available() throws IOException { |
| if (closed) |
| throw new IOException("Stream is closed"); |
| return is.available(); // TBD: |
| } |
| |
| @Override |
| public void close() throws IOException { |
| if (!closed) { |
| closed = true; |
| is.close(); |
| } |
| } |
| } |
| } |
