--- /dev/null
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package be.nikiroo.utils.streams;
+
+import java.io.UnsupportedEncodingException;
+
+/**
+ * Utilities for encoding and decoding the Base64 representation of
+ * binary data. See RFCs <a
+ * href="http://www.ietf.org/rfc/rfc2045.txt">2045</a> and <a
+ * href="http://www.ietf.org/rfc/rfc3548.txt">3548</a>.
+ */
+class Base64 {
+ /**
+ * Default values for encoder/decoder flags.
+ */
+ public static final int DEFAULT = 0;
+
+ /**
+ * Encoder flag bit to omit the padding '=' characters at the end
+ * of the output (if any).
+ */
+ public static final int NO_PADDING = 1;
+
+ /**
+ * Encoder flag bit to omit all line terminators (i.e., the output
+ * will be on one long line).
+ */
+ public static final int NO_WRAP = 2;
+
+ /**
+ * Encoder flag bit to indicate lines should be terminated with a
+ * CRLF pair instead of just an LF. Has no effect if {@code
+ * NO_WRAP} is specified as well.
+ */
+ public static final int CRLF = 4;
+
+ /**
+ * Encoder/decoder flag bit to indicate using the "URL and
+ * filename safe" variant of Base64 (see RFC 3548 section 4) where
+ * {@code -} and {@code _} are used in place of {@code +} and
+ * {@code /}.
+ */
+ public static final int URL_SAFE = 8;
+
+ /**
+ * Flag to pass to {@link Base64OutputStream} to indicate that it
+ * should not close the output stream it is wrapping when it
+ * itself is closed.
+ */
+ public static final int NO_CLOSE = 16;
+
+ // --------------------------------------------------------
+ // shared code
+ // --------------------------------------------------------
+
+ /* package */ static abstract class Coder {
+ public byte[] output;
+ public int op;
+
+ /**
+ * Encode/decode another block of input data. this.output is
+ * provided by the caller, and must be big enough to hold all
+ * the coded data. On exit, this.opwill be set to the length
+ * of the coded data.
+ *
+ * @param finish true if this is the final call to process for
+ * this object. Will finalize the coder state and
+ * include any final bytes in the output.
+ *
+ * @return true if the input so far is good; false if some
+ * error has been detected in the input stream..
+ */
+ public abstract boolean process(byte[] input, int offset, int len, boolean finish);
+
+ /**
+ * @return the maximum number of bytes a call to process()
+ * could produce for the given number of input bytes. This may
+ * be an overestimate.
+ */
+ public abstract int maxOutputSize(int len);
+ }
+
+ // --------------------------------------------------------
+ // decoding
+ // --------------------------------------------------------
+
+ /**
+ * Decode the Base64-encoded data in input and return the data in
+ * a new byte array.
+ *
+ * <p>The padding '=' characters at the end are considered optional, but
+ * if any are present, there must be the correct number of them.
+ *
+ * @param str the input String to decode, which is converted to
+ * bytes using the default charset
+ * @param flags controls certain features of the decoded output.
+ * Pass {@code DEFAULT} to decode standard Base64.
+ *
+ * @throws IllegalArgumentException if the input contains
+ * incorrect padding
+ */
+ public static byte[] decode(String str, int flags) {
+ return decode(str.getBytes(), flags);
+ }
+
+ /**
+ * Decode the Base64-encoded data in input and return the data in
+ * a new byte array.
+ *
+ * <p>The padding '=' characters at the end are considered optional, but
+ * if any are present, there must be the correct number of them.
+ *
+ * @param input the input array to decode
+ * @param flags controls certain features of the decoded output.
+ * Pass {@code DEFAULT} to decode standard Base64.
+ *
+ * @throws IllegalArgumentException if the input contains
+ * incorrect padding
+ */
+ public static byte[] decode(byte[] input, int flags) {
+ return decode(input, 0, input.length, flags);
+ }
+
+ /**
+ * Decode the Base64-encoded data in input and return the data in
+ * a new byte array.
+ *
+ * <p>The padding '=' characters at the end are considered optional, but
+ * if any are present, there must be the correct number of them.
+ *
+ * @param input the data to decode
+ * @param offset the position within the input array at which to start
+ * @param len the number of bytes of input to decode
+ * @param flags controls certain features of the decoded output.
+ * Pass {@code DEFAULT} to decode standard Base64.
+ *
+ * @throws IllegalArgumentException if the input contains
+ * incorrect padding
+ */
+ public static byte[] decode(byte[] input, int offset, int len, int flags) {
+ // Allocate space for the most data the input could represent.
+ // (It could contain less if it contains whitespace, etc.)
+ Decoder decoder = new Decoder(flags, new byte[len*3/4]);
+
+ if (!decoder.process(input, offset, len, true)) {
+ throw new IllegalArgumentException("bad base-64");
+ }
+
+ // Maybe we got lucky and allocated exactly enough output space.
+ if (decoder.op == decoder.output.length) {
+ return decoder.output;
+ }
+
+ // Need to shorten the array, so allocate a new one of the
+ // right size and copy.
+ byte[] temp = new byte[decoder.op];
+ System.arraycopy(decoder.output, 0, temp, 0, decoder.op);
+ return temp;
+ }
+
+ /* package */ static class Decoder extends Coder {
+ /**
+ * Lookup table for turning bytes into their position in the
+ * Base64 alphabet.
+ */
+ private static final int DECODE[] = {
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63,
+ 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -2, -1, -1,
+ -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
+ 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1,
+ -1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
+ 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ };
+
+ /**
+ * Decode lookup table for the "web safe" variant (RFC 3548
+ * sec. 4) where - and _ replace + and /.
+ */
+ private static final int DECODE_WEBSAFE[] = {
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1,
+ 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -2, -1, -1,
+ -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
+ 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, 63,
+ -1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
+ 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ };
+
+ /** Non-data values in the DECODE arrays. */
+ private static final int SKIP = -1;
+ private static final int EQUALS = -2;
+
+ /**
+ * States 0-3 are reading through the next input tuple.
+ * State 4 is having read one '=' and expecting exactly
+ * one more.
+ * State 5 is expecting no more data or padding characters
+ * in the input.
+ * State 6 is the error state; an error has been detected
+ * in the input and no future input can "fix" it.
+ */
+ private int state; // state number (0 to 6)
+ private int value;
+
+ final private int[] alphabet;
+
+ public Decoder(int flags, byte[] output) {
+ this.output = output;
+
+ alphabet = ((flags & URL_SAFE) == 0) ? DECODE : DECODE_WEBSAFE;
+ state = 0;
+ value = 0;
+ }
+
+ /**
+ * @return an overestimate for the number of bytes {@code
+ * len} bytes could decode to.
+ */
+ public int maxOutputSize(int len) {
+ return len * 3/4 + 10;
+ }
+
+ /**
+ * Decode another block of input data.
+ *
+ * @return true if the state machine is still healthy. false if
+ * bad base-64 data has been detected in the input stream.
+ */
+ public boolean process(byte[] input, int offset, int len, boolean finish) {
+ if (this.state == 6) return false;
+
+ int p = offset;
+ len += offset;
+
+ // Using local variables makes the decoder about 12%
+ // faster than if we manipulate the member variables in
+ // the loop. (Even alphabet makes a measurable
+ // difference, which is somewhat surprising to me since
+ // the member variable is final.)
+ int state = this.state;
+ int value = this.value;
+ int op = 0;
+ final byte[] output = this.output;
+ final int[] alphabet = this.alphabet;
+
+ while (p < len) {
+ // Try the fast path: we're starting a new tuple and the
+ // next four bytes of the input stream are all data
+ // bytes. This corresponds to going through states
+ // 0-1-2-3-0. We expect to use this method for most of
+ // the data.
+ //
+ // If any of the next four bytes of input are non-data
+ // (whitespace, etc.), value will end up negative. (All
+ // the non-data values in decode are small negative
+ // numbers, so shifting any of them up and or'ing them
+ // together will result in a value with its top bit set.)
+ //
+ // You can remove this whole block and the output should
+ // be the same, just slower.
+ if (state == 0) {
+ while (p+4 <= len &&
+ (value = ((alphabet[input[p] & 0xff] << 18) |
+ (alphabet[input[p+1] & 0xff] << 12) |
+ (alphabet[input[p+2] & 0xff] << 6) |
+ (alphabet[input[p+3] & 0xff]))) >= 0) {
+ output[op+2] = (byte) value;
+ output[op+1] = (byte) (value >> 8);
+ output[op] = (byte) (value >> 16);
+ op += 3;
+ p += 4;
+ }
+ if (p >= len) break;
+ }
+
+ // The fast path isn't available -- either we've read a
+ // partial tuple, or the next four input bytes aren't all
+ // data, or whatever. Fall back to the slower state
+ // machine implementation.
+
+ int d = alphabet[input[p++] & 0xff];
+
+ switch (state) {
+ case 0:
+ if (d >= 0) {
+ value = d;
+ ++state;
+ } else if (d != SKIP) {
+ this.state = 6;
+ return false;
+ }
+ break;
+
+ case 1:
+ if (d >= 0) {
+ value = (value << 6) | d;
+ ++state;
+ } else if (d != SKIP) {
+ this.state = 6;
+ return false;
+ }
+ break;
+
+ case 2:
+ if (d >= 0) {
+ value = (value << 6) | d;
+ ++state;
+ } else if (d == EQUALS) {
+ // Emit the last (partial) output tuple;
+ // expect exactly one more padding character.
+ output[op++] = (byte) (value >> 4);
+ state = 4;
+ } else if (d != SKIP) {
+ this.state = 6;
+ return false;
+ }
+ break;
+
+ case 3:
+ if (d >= 0) {
+ // Emit the output triple and return to state 0.
+ value = (value << 6) | d;
+ output[op+2] = (byte) value;
+ output[op+1] = (byte) (value >> 8);
+ output[op] = (byte) (value >> 16);
+ op += 3;
+ state = 0;
+ } else if (d == EQUALS) {
+ // Emit the last (partial) output tuple;
+ // expect no further data or padding characters.
+ output[op+1] = (byte) (value >> 2);
+ output[op] = (byte) (value >> 10);
+ op += 2;
+ state = 5;
+ } else if (d != SKIP) {
+ this.state = 6;
+ return false;
+ }
+ break;
+
+ case 4:
+ if (d == EQUALS) {
+ ++state;
+ } else if (d != SKIP) {
+ this.state = 6;
+ return false;
+ }
+ break;
+
+ case 5:
+ if (d != SKIP) {
+ this.state = 6;
+ return false;
+ }
+ break;
+ }
+ }
+
+ if (!finish) {
+ // We're out of input, but a future call could provide
+ // more.
+ this.state = state;
+ this.value = value;
+ this.op = op;
+ return true;
+ }
+
+ // Done reading input. Now figure out where we are left in
+ // the state machine and finish up.
+
+ switch (state) {
+ case 0:
+ // Output length is a multiple of three. Fine.
+ break;
+ case 1:
+ // Read one extra input byte, which isn't enough to
+ // make another output byte. Illegal.
+ this.state = 6;
+ return false;
+ case 2:
+ // Read two extra input bytes, enough to emit 1 more
+ // output byte. Fine.
+ output[op++] = (byte) (value >> 4);
+ break;
+ case 3:
+ // Read three extra input bytes, enough to emit 2 more
+ // output bytes. Fine.
+ output[op++] = (byte) (value >> 10);
+ output[op++] = (byte) (value >> 2);
+ break;
+ case 4:
+ // Read one padding '=' when we expected 2. Illegal.
+ this.state = 6;
+ return false;
+ case 5:
+ // Read all the padding '='s we expected and no more.
+ // Fine.
+ break;
+ }
+
+ this.state = state;
+ this.op = op;
+ return true;
+ }
+ }
+
+ // --------------------------------------------------------
+ // encoding
+ // --------------------------------------------------------
+
+ /**
+ * Base64-encode the given data and return a newly allocated
+ * String with the result.
+ *
+ * @param input the data to encode
+ * @param flags controls certain features of the encoded output.
+ * Passing {@code DEFAULT} results in output that
+ * adheres to RFC 2045.
+ */
+ public static String encodeToString(byte[] input, int flags) {
+ try {
+ return new String(encode(input, flags), "US-ASCII");
+ } catch (UnsupportedEncodingException e) {
+ // US-ASCII is guaranteed to be available.
+ throw new AssertionError(e);
+ }
+ }
+
+ /**
+ * Base64-encode the given data and return a newly allocated
+ * String with the result.
+ *
+ * @param input the data to encode
+ * @param offset the position within the input array at which to
+ * start
+ * @param len the number of bytes of input to encode
+ * @param flags controls certain features of the encoded output.
+ * Passing {@code DEFAULT} results in output that
+ * adheres to RFC 2045.
+ */
+ public static String encodeToString(byte[] input, int offset, int len, int flags) {
+ try {
+ return new String(encode(input, offset, len, flags), "US-ASCII");
+ } catch (UnsupportedEncodingException e) {
+ // US-ASCII is guaranteed to be available.
+ throw new AssertionError(e);
+ }
+ }
+
+ /**
+ * Base64-encode the given data and return a newly allocated
+ * byte[] with the result.
+ *
+ * @param input the data to encode
+ * @param flags controls certain features of the encoded output.
+ * Passing {@code DEFAULT} results in output that
+ * adheres to RFC 2045.
+ */
+ public static byte[] encode(byte[] input, int flags) {
+ return encode(input, 0, input.length, flags);
+ }
+
+ /**
+ * Base64-encode the given data and return a newly allocated
+ * byte[] with the result.
+ *
+ * @param input the data to encode
+ * @param offset the position within the input array at which to
+ * start
+ * @param len the number of bytes of input to encode
+ * @param flags controls certain features of the encoded output.
+ * Passing {@code DEFAULT} results in output that
+ * adheres to RFC 2045.
+ */
+ public static byte[] encode(byte[] input, int offset, int len, int flags) {
+ Encoder encoder = new Encoder(flags, null);
+
+ // Compute the exact length of the array we will produce.
+ int output_len = len / 3 * 4;
+
+ // Account for the tail of the data and the padding bytes, if any.
+ if (encoder.do_padding) {
+ if (len % 3 > 0) {
+ output_len += 4;
+ }
+ } else {
+ switch (len % 3) {
+ case 0: break;
+ case 1: output_len += 2; break;
+ case 2: output_len += 3; break;
+ }
+ }
+
+ // Account for the newlines, if any.
+ if (encoder.do_newline && len > 0) {
+ output_len += (((len-1) / (3 * Encoder.LINE_GROUPS)) + 1) *
+ (encoder.do_cr ? 2 : 1);
+ }
+
+ encoder.output = new byte[output_len];
+ encoder.process(input, offset, len, true);
+
+ assert encoder.op == output_len;
+
+ return encoder.output;
+ }
+
+ /* package */ static class Encoder extends Coder {
+ /**
+ * Emit a new line every this many output tuples. Corresponds to
+ * a 76-character line length (the maximum allowable according to
+ * <a href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045</a>).
+ */
+ public static final int LINE_GROUPS = 19;
+
+ /**
+ * Lookup table for turning Base64 alphabet positions (6 bits)
+ * into output bytes.
+ */
+ private static final byte ENCODE[] = {
+ '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', '+', '/',
+ };
+
+ /**
+ * Lookup table for turning Base64 alphabet positions (6 bits)
+ * into output bytes.
+ */
+ private static final byte ENCODE_WEBSAFE[] = {
+ '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', '-', '_',
+ };
+
+ final private byte[] tail;
+ /* package */ int tailLen;
+ private int count;
+
+ final public boolean do_padding;
+ final public boolean do_newline;
+ final public boolean do_cr;
+ final private byte[] alphabet;
+
+ public Encoder(int flags, byte[] output) {
+ this.output = output;
+
+ do_padding = (flags & NO_PADDING) == 0;
+ do_newline = (flags & NO_WRAP) == 0;
+ do_cr = (flags & CRLF) != 0;
+ alphabet = ((flags & URL_SAFE) == 0) ? ENCODE : ENCODE_WEBSAFE;
+
+ tail = new byte[2];
+ tailLen = 0;
+
+ count = do_newline ? LINE_GROUPS : -1;
+ }
+
+ /**
+ * @return an overestimate for the number of bytes {@code
+ * len} bytes could encode to.
+ */
+ public int maxOutputSize(int len) {
+ return len * 8/5 + 10;
+ }
+
+ public boolean process(byte[] input, int offset, int len, boolean finish) {
+ // Using local variables makes the encoder about 9% faster.
+ final byte[] alphabet = this.alphabet;
+ final byte[] output = this.output;
+ int op = 0;
+ int count = this.count;
+
+ int p = offset;
+ len += offset;
+ int v = -1;
+
+ // First we need to concatenate the tail of the previous call
+ // with any input bytes available now and see if we can empty
+ // the tail.
+
+ switch (tailLen) {
+ case 0:
+ // There was no tail.
+ break;
+
+ case 1:
+ if (p+2 <= len) {
+ // A 1-byte tail with at least 2 bytes of
+ // input available now.
+ v = ((tail[0] & 0xff) << 16) |
+ ((input[p++] & 0xff) << 8) |
+ (input[p++] & 0xff);
+ tailLen = 0;
+ };
+ break;
+
+ case 2:
+ if (p+1 <= len) {
+ // A 2-byte tail with at least 1 byte of input.
+ v = ((tail[0] & 0xff) << 16) |
+ ((tail[1] & 0xff) << 8) |
+ (input[p++] & 0xff);
+ tailLen = 0;
+ }
+ break;
+ }
+
+ if (v != -1) {
+ output[op++] = alphabet[(v >> 18) & 0x3f];
+ output[op++] = alphabet[(v >> 12) & 0x3f];
+ output[op++] = alphabet[(v >> 6) & 0x3f];
+ output[op++] = alphabet[v & 0x3f];
+ if (--count == 0) {
+ if (do_cr) output[op++] = '\r';
+ output[op++] = '\n';
+ count = LINE_GROUPS;
+ }
+ }
+
+ // At this point either there is no tail, or there are fewer
+ // than 3 bytes of input available.
+
+ // The main loop, turning 3 input bytes into 4 output bytes on
+ // each iteration.
+ while (p+3 <= len) {
+ v = ((input[p] & 0xff) << 16) |
+ ((input[p+1] & 0xff) << 8) |
+ (input[p+2] & 0xff);
+ output[op] = alphabet[(v >> 18) & 0x3f];
+ output[op+1] = alphabet[(v >> 12) & 0x3f];
+ output[op+2] = alphabet[(v >> 6) & 0x3f];
+ output[op+3] = alphabet[v & 0x3f];
+ p += 3;
+ op += 4;
+ if (--count == 0) {
+ if (do_cr) output[op++] = '\r';
+ output[op++] = '\n';
+ count = LINE_GROUPS;
+ }
+ }
+
+ if (finish) {
+ // Finish up the tail of the input. Note that we need to
+ // consume any bytes in tail before any bytes
+ // remaining in input; there should be at most two bytes
+ // total.
+
+ if (p-tailLen == len-1) {
+ int t = 0;
+ v = ((tailLen > 0 ? tail[t++] : input[p++]) & 0xff) << 4;
+ tailLen -= t;
+ output[op++] = alphabet[(v >> 6) & 0x3f];
+ output[op++] = alphabet[v & 0x3f];
+ if (do_padding) {
+ output[op++] = '=';
+ output[op++] = '=';
+ }
+ if (do_newline) {
+ if (do_cr) output[op++] = '\r';
+ output[op++] = '\n';
+ }
+ } else if (p-tailLen == len-2) {
+ int t = 0;
+ v = (((tailLen > 1 ? tail[t++] : input[p++]) & 0xff) << 10) |
+ (((tailLen > 0 ? tail[t++] : input[p++]) & 0xff) << 2);
+ tailLen -= t;
+ output[op++] = alphabet[(v >> 12) & 0x3f];
+ output[op++] = alphabet[(v >> 6) & 0x3f];
+ output[op++] = alphabet[v & 0x3f];
+ if (do_padding) {
+ output[op++] = '=';
+ }
+ if (do_newline) {
+ if (do_cr) output[op++] = '\r';
+ output[op++] = '\n';
+ }
+ } else if (do_newline && op > 0 && count != LINE_GROUPS) {
+ if (do_cr) output[op++] = '\r';
+ output[op++] = '\n';
+ }
+
+ assert tailLen == 0;
+ assert p == len;
+ } else {
+ // Save the leftovers in tail to be consumed on the next
+ // call to encodeInternal.
+
+ if (p == len-1) {
+ tail[tailLen++] = input[p];
+ } else if (p == len-2) {
+ tail[tailLen++] = input[p];
+ tail[tailLen++] = input[p+1];
+ }
+ }
+
+ this.op = op;
+ this.count = count;
+
+ return true;
+ }
+ }
+
+ private Base64() { } // don't instantiate
+}
git://git.nikiroo.be / nikiroo-utils.git / commitdiff