| /* Jackson JSON-processor. |
| * |
| * Copyright (c) 2007- Tatu Saloranta, tatu.saloranta@iki.fi |
| * |
| * Licensed under the License specified in file LICENSE, included with |
| * the source code and binary code bundles. |
| * You may not use this file except in compliance with the License. |
| * |
| * 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 org.codehaus.jackson; |
| |
| import java.util.Arrays; |
| |
| /** |
| * Abstract base class used to define specific details of which |
| * variant of Base64 encoding/decoding is to be used. Although there is |
| * somewhat standard basic version (so-called "MIME Base64"), other variants |
| * exists, see <a href="http://en.wikipedia.org/wiki/Base64">Base64 Wikipedia entry</a> for details. |
| * |
| * @author Tatu Saloranta |
| * |
| * @since 0.9.3 |
| */ |
| public final class Base64Variant |
| { |
| /** |
| * Placeholder used by "no padding" variant, to be used when a character |
| * value is needed. |
| */ |
| final static char PADDING_CHAR_NONE = '\0'; |
| |
| /** |
| * Marker used to denote ascii characters that do not correspond |
| * to a 6-bit value (in this variant), and is not used as a padding |
| * character. |
| */ |
| public final static int BASE64_VALUE_INVALID = -1; |
| |
| /** |
| * Marker used to denote ascii character (in decoding table) that |
| * is the padding character using this variant (if any). |
| */ |
| public final static int BASE64_VALUE_PADDING = -2; |
| |
| /* |
| /********************************************************** |
| /* Encoding/decoding tables |
| /********************************************************** |
| */ |
| |
| /** |
| * Decoding table used for base 64 decoding. |
| */ |
| private final int[] _asciiToBase64 = new int[128]; |
| |
| /** |
| * Encoding table used for base 64 decoding when output is done |
| * as characters. |
| */ |
| private final char[] _base64ToAsciiC = new char[64]; |
| |
| /** |
| * Alternative encoding table used for base 64 decoding when output is done |
| * as ascii bytes. |
| */ |
| private final byte[] _base64ToAsciiB = new byte[64]; |
| |
| /* |
| /********************************************************** |
| /* Other configuration |
| /********************************************************** |
| */ |
| |
| /** |
| * Symbolic name of variant; used for diagnostics/debugging. |
| */ |
| final String _name; |
| |
| /** |
| * Whether this variant uses padding or not. |
| */ |
| final boolean _usesPadding; |
| |
| /** |
| * Characted used for padding, if any ({@link #PADDING_CHAR_NONE} if not). |
| */ |
| final char _paddingChar; |
| |
| /** |
| * Maximum number of encoded base64 characters to output during encoding |
| * before adding a linefeed, if line length is to be limited |
| * ({@link java.lang.Integer#MAX_VALUE} if not limited). |
| *<p> |
| * Note: for some output modes (when writing attributes) linefeeds may |
| * need to be avoided, and this value ignored. |
| */ |
| final int _maxLineLength; |
| |
| /* |
| /********************************************************** |
| /* Life-cycle |
| /********************************************************** |
| */ |
| |
| public Base64Variant(String name, String base64Alphabet, boolean usesPadding, char paddingChar, int maxLineLength) |
| { |
| _name = name; |
| _usesPadding = usesPadding; |
| _paddingChar = paddingChar; |
| _maxLineLength = maxLineLength; |
| |
| // Ok and then we need to create codec tables. |
| |
| // First the main encoding table: |
| int alphaLen = base64Alphabet.length(); |
| if (alphaLen != 64) { |
| throw new IllegalArgumentException("Base64Alphabet length must be exactly 64 (was "+alphaLen+")"); |
| } |
| |
| // And then secondary encoding table and decoding table: |
| base64Alphabet.getChars(0, alphaLen, _base64ToAsciiC, 0); |
| Arrays.fill(_asciiToBase64, BASE64_VALUE_INVALID); |
| for (int i = 0; i < alphaLen; ++i) { |
| char alpha = _base64ToAsciiC[i]; |
| _base64ToAsciiB[i] = (byte) alpha; |
| _asciiToBase64[alpha] = i; |
| } |
| |
| // Plus if we use padding, add that in too |
| if (usesPadding) { |
| _asciiToBase64[(int) paddingChar] = BASE64_VALUE_PADDING; |
| } |
| } |
| |
| /** |
| * "Copy constructor" that can be used when the base alphabet is identical |
| * to one used by another variant except for the maximum line length |
| * (and obviously, name). |
| */ |
| public Base64Variant(Base64Variant base, String name, int maxLineLength) |
| { |
| this(base, name, base._usesPadding, base._paddingChar, maxLineLength); |
| } |
| |
| /** |
| * "Copy constructor" that can be used when the base alphabet is identical |
| * to one used by another variant, but other details (padding, maximum |
| * line length) differ |
| */ |
| public Base64Variant(Base64Variant base, String name, boolean usesPadding, char paddingChar, int maxLineLength) |
| { |
| _name = name; |
| byte[] srcB = base._base64ToAsciiB; |
| System.arraycopy(srcB, 0, this._base64ToAsciiB, 0, srcB.length); |
| char[] srcC = base._base64ToAsciiC; |
| System.arraycopy(srcC, 0, this._base64ToAsciiC, 0, srcC.length); |
| int[] srcV = base._asciiToBase64; |
| System.arraycopy(srcV, 0, this._asciiToBase64, 0, srcV.length); |
| |
| _usesPadding = usesPadding; |
| _paddingChar = paddingChar; |
| _maxLineLength = maxLineLength; |
| } |
| |
| /* |
| /********************************************************** |
| /* Public accessors |
| /********************************************************** |
| */ |
| |
| public String getName() { return _name; } |
| |
| public boolean usesPadding() { return _usesPadding; } |
| public boolean usesPaddingChar(char c) { return c == _paddingChar; } |
| public boolean usesPaddingChar(int ch) { return ch == (int) _paddingChar; } |
| public char getPaddingChar() { return _paddingChar; } |
| public byte getPaddingByte() { return (byte)_paddingChar; } |
| |
| public int getMaxLineLength() { return _maxLineLength; } |
| |
| /* |
| /********************************************************** |
| /* Decoding support |
| /********************************************************** |
| */ |
| |
| /** |
| * @return 6-bit decoded value, if valid character; |
| */ |
| public int decodeBase64Char(char c) |
| { |
| int ch = (int) c; |
| return (ch <= 127) ? _asciiToBase64[ch] : BASE64_VALUE_INVALID; |
| } |
| |
| public int decodeBase64Char(int ch) |
| { |
| return (ch <= 127) ? _asciiToBase64[ch] : BASE64_VALUE_INVALID; |
| } |
| |
| public int decodeBase64Byte(byte b) |
| { |
| int ch = (int) b; |
| return (ch <= 127) ? _asciiToBase64[ch] : BASE64_VALUE_INVALID; |
| } |
| |
| /* |
| /********************************************************** |
| /* Encoding support |
| /********************************************************** |
| */ |
| |
| public char encodeBase64BitsAsChar(int value) |
| { |
| /* Let's assume caller has done necessary checks; this |
| * method must be fast and inlinable |
| */ |
| return _base64ToAsciiC[value]; |
| } |
| |
| /** |
| * Method that encodes given right-aligned (LSB) 24-bit value |
| * into 4 base64 characters, stored in given result buffer. |
| */ |
| public int encodeBase64Chunk(int b24, char[] buffer, int ptr) |
| { |
| buffer[ptr++] = _base64ToAsciiC[(b24 >> 18) & 0x3F]; |
| buffer[ptr++] = _base64ToAsciiC[(b24 >> 12) & 0x3F]; |
| buffer[ptr++] = _base64ToAsciiC[(b24 >> 6) & 0x3F]; |
| buffer[ptr++] = _base64ToAsciiC[b24 & 0x3F]; |
| return ptr; |
| } |
| |
| public void encodeBase64Chunk(StringBuilder sb, int b24) |
| { |
| sb.append(_base64ToAsciiC[(b24 >> 18) & 0x3F]); |
| sb.append(_base64ToAsciiC[(b24 >> 12) & 0x3F]); |
| sb.append(_base64ToAsciiC[(b24 >> 6) & 0x3F]); |
| sb.append(_base64ToAsciiC[b24 & 0x3F]); |
| } |
| |
| /** |
| * Method that outputs partial chunk (which only encodes one |
| * or two bytes of data). Data given is still aligned same as if |
| * it as full data; that is, missing data is at the "right end" |
| * (LSB) of int. |
| * |
| * @param outputBytes Number of encoded bytes included (either 1 or 2) |
| */ |
| public int encodeBase64Partial(int bits, int outputBytes, char[] buffer, int outPtr) |
| { |
| buffer[outPtr++] = _base64ToAsciiC[(bits >> 18) & 0x3F]; |
| buffer[outPtr++] = _base64ToAsciiC[(bits >> 12) & 0x3F]; |
| if (_usesPadding) { |
| buffer[outPtr++] = (outputBytes == 2) ? |
| _base64ToAsciiC[(bits >> 6) & 0x3F] : _paddingChar; |
| buffer[outPtr++] = _paddingChar; |
| } else { |
| if (outputBytes == 2) { |
| buffer[outPtr++] = _base64ToAsciiC[(bits >> 6) & 0x3F]; |
| } |
| } |
| return outPtr; |
| } |
| |
| public void encodeBase64Partial(StringBuilder sb, int bits, int outputBytes) |
| { |
| sb.append(_base64ToAsciiC[(bits >> 18) & 0x3F]); |
| sb.append(_base64ToAsciiC[(bits >> 12) & 0x3F]); |
| if (_usesPadding) { |
| sb.append((outputBytes == 2) ? |
| _base64ToAsciiC[(bits >> 6) & 0x3F] : _paddingChar); |
| sb.append(_paddingChar); |
| } else { |
| if (outputBytes == 2) { |
| sb.append(_base64ToAsciiC[(bits >> 6) & 0x3F]); |
| } |
| } |
| } |
| |
| public byte encodeBase64BitsAsByte(int value) |
| { |
| // As with above, assuming it is 6-bit value |
| return _base64ToAsciiB[value]; |
| } |
| |
| /** |
| * Method that encodes given right-aligned (LSB) 24-bit value |
| * into 4 base64 bytes (ascii), stored in given result buffer. |
| */ |
| public int encodeBase64Chunk(int b24, byte[] buffer, int ptr) |
| { |
| buffer[ptr++] = _base64ToAsciiB[(b24 >> 18) & 0x3F]; |
| buffer[ptr++] = _base64ToAsciiB[(b24 >> 12) & 0x3F]; |
| buffer[ptr++] = _base64ToAsciiB[(b24 >> 6) & 0x3F]; |
| buffer[ptr++] = _base64ToAsciiB[b24 & 0x3F]; |
| return ptr; |
| } |
| |
| /** |
| * Method that outputs partial chunk (which only encodes one |
| * or two bytes of data). Data given is still aligned same as if |
| * it as full data; that is, missing data is at the "right end" |
| * (LSB) of int. |
| * |
| * @param outputBytes Number of encoded bytes included (either 1 or 2) |
| */ |
| public int encodeBase64Partial(int bits, int outputBytes, byte[] buffer, int outPtr) |
| { |
| buffer[outPtr++] = _base64ToAsciiB[(bits >> 18) & 0x3F]; |
| buffer[outPtr++] = _base64ToAsciiB[(bits >> 12) & 0x3F]; |
| if (_usesPadding) { |
| byte pb = (byte) _paddingChar; |
| buffer[outPtr++] = (outputBytes == 2) ? |
| _base64ToAsciiB[(bits >> 6) & 0x3F] : pb; |
| buffer[outPtr++] = pb; |
| } else { |
| if (outputBytes == 2) { |
| buffer[outPtr++] = _base64ToAsciiB[(bits >> 6) & 0x3F]; |
| } |
| } |
| return outPtr; |
| } |
| |
| /** |
| * Convenience method for converting given byte array as base64 encoded |
| * String using this variant's settings. |
| * Resulting value is "raw", that is, not enclosed in double-quotes. |
| * |
| * @param input Byte array to encode |
| * |
| * @since 1.6 |
| */ |
| public String encode(byte[] input) |
| { |
| return encode(input, false); |
| } |
| |
| /** |
| * Convenience method for converting given byte array as base64 encoded |
| * String using this variant's settings, optionally enclosed in |
| * double-quotes. |
| * |
| * @param input Byte array to encode |
| * @param addQuotes Whether to surround resulting value in double quotes |
| * or not |
| * |
| * @since 1.6 |
| */ |
| public String encode(byte[] input, boolean addQuotes) |
| { |
| int inputEnd = input.length; |
| StringBuilder sb; |
| { |
| // let's approximate... 33% overhead, ~= 3/8 (0.375) |
| int outputLen = inputEnd + (inputEnd >> 2) + (inputEnd >> 3); |
| sb = new StringBuilder(outputLen); |
| } |
| if (addQuotes) { |
| sb.append('"'); |
| } |
| |
| int chunksBeforeLF = getMaxLineLength() >> 2; |
| |
| // Ok, first we loop through all full triplets of data: |
| int inputPtr = 0; |
| int safeInputEnd = inputEnd-3; // to get only full triplets |
| |
| while (inputPtr <= safeInputEnd) { |
| // First, mash 3 bytes into lsb of 32-bit int |
| int b24 = ((int) input[inputPtr++]) << 8; |
| b24 |= ((int) input[inputPtr++]) & 0xFF; |
| b24 = (b24 << 8) | (((int) input[inputPtr++]) & 0xFF); |
| encodeBase64Chunk(sb, b24); |
| if (--chunksBeforeLF <= 0) { |
| // note: must quote in JSON value, so not really useful... |
| sb.append('\\'); |
| sb.append('n'); |
| chunksBeforeLF = getMaxLineLength() >> 2; |
| } |
| } |
| |
| // And then we may have 1 or 2 leftover bytes to encode |
| int inputLeft = inputEnd - inputPtr; // 0, 1 or 2 |
| if (inputLeft > 0) { // yes, but do we have room for output? |
| int b24 = ((int) input[inputPtr++]) << 16; |
| if (inputLeft == 2) { |
| b24 |= (((int) input[inputPtr++]) & 0xFF) << 8; |
| } |
| encodeBase64Partial(sb, b24, inputLeft); |
| } |
| |
| if (addQuotes) { |
| sb.append('"'); |
| } |
| return sb.toString(); |
| } |
| |
| /* |
| /********************************************************** |
| /* other methods |
| /********************************************************** |
| */ |
| |
| // @Override |
| public String toString() { return _name; } |
| } |
| |