| New file |
| | |
| | | package cn.gistack.system.user.sync.util; |
| | | |
| | | import java.io.FilterOutputStream; |
| | | import java.io.IOException; |
| | | import java.io.InputStream; |
| | | import java.io.OutputStream; |
| | | import java.nio.ByteBuffer; |
| | | import java.nio.charset.Charset; |
| | | import java.util.Arrays; |
| | | |
| | | /** |
| | | * 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 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) { |
| | | if (lineSeparator == null) { |
| | | throw new NullPointerException(); |
| | | } |
| | | 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 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 {@code 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) { |
| | | if(os == null) { |
| | | throw new NullPointerException(); |
| | | } |
| | | 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 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(Charset.forName("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) { |
| | | if(is == null) { |
| | | throw new NullPointerException(); |
| | | } |
| | | 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(); |
| | | } |
| | | } |
| | | } |
| | | } |