|
|
@@ -0,0 +1,978 @@
|
|
|
+package com.miekir.common.utils;
|
|
|
+
|
|
|
+import java.io.FilterOutputStream;
|
|
|
+import java.io.IOException;
|
|
|
+import java.io.InputStream;
|
|
|
+import java.io.OutputStream;
|
|
|
+import java.nio.ByteBuffer;
|
|
|
+import java.nio.charset.StandardCharsets;
|
|
|
+import java.util.Arrays;
|
|
|
+import java.util.Objects;
|
|
|
+
|
|
|
+/**
|
|
|
+ * 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");
|
|
|
+ // Android-changed: Upstream fix to avoid overflow.
|
|
|
+ // This upstream fix is from beyond OpenJDK8u121-b13. http://b/62368386
|
|
|
+ // if (off < 0 || len < 0 || off + len > b.length)
|
|
|
+ if (off < 0 || len < 0 || len > b.length - off)
|
|
|
+ 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();
|
|
|
+ }
|
|
|
+ }
|
|
|
+ }
|
|
|
+}
|
詹子聪