| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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 |
| * |
| * https://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 org.apache.commons.codec.binary; |
| |
| import java.math.BigInteger; |
| import java.util.Arrays; |
| import java.util.Objects; |
| |
| import org.apache.commons.codec.CodecPolicy; |
| |
| /** |
| * Provides Base64 encoding and decoding as defined by <a href="https://www.ietf.org/rfc/rfc2045">RFC 2045 Multipurpose Internet Mail Extensions (MIME) Part |
| * One: Format of Internet Message Bodies</a> and portions of <a href="https://datatracker.ietf.org/doc/html/rfc4648">RFC 4648 The Base16, Base32, and Base64 |
| * Data Encodings</a> |
| * |
| * <p> |
| * This class implements <a href="https://www.ietf.org/rfc/rfc2045#section-6.8">RFC 2045 6.8. Base64 Content-Transfer-Encoding</a>. |
| * </p> |
| * <p> |
| * The class can be parameterized in the following manner with its {@link Builder}: |
| * </p> |
| * <ul> |
| * <li>URL-safe mode: Default off.</li> |
| * <li>Line length: Default 76. Line length that aren't multiples of 4 will still essentially end up being multiples of 4 in the encoded data. |
| * <li>Line separator: Default is CRLF ({@code "\r\n"})</li> |
| * <li>Strict or lenient decoding policy; default is {@link CodecPolicy#LENIENT}.</li> |
| * <li>Custom decoding table.</li> |
| * <li>Custom encoding table.</li> |
| * <li>Padding; defaults is {@code '='}.</li> |
| * </ul> |
| * <p> |
| * The URL-safe parameter is only applied to encode operations. Decoding seamlessly handles both modes, see also |
| * {@code Builder#setDecodeTableFormat(DecodeTableFormat)}. |
| * </p> |
| * <p> |
| * Since this class operates directly on byte streams, and not character streams, it is hard-coded to only encode/decode character encodings which are |
| * compatible with the lower 127 ASCII chart (ISO-8859-1, Windows-1252, UTF-8, etc). |
| * </p> |
| * <p> |
| * This class is thread-safe. |
| * </p> |
| * <p> |
| * To configure a new instance, use a {@link Builder}. For example: |
| * </p> |
| * |
| * <pre> |
| * Base64 base64 = Base64.builder() |
| * .setDecodingPolicy(CodecPolicy.LENIENT) // default is lenient, null resets to default |
| * .setEncodeTable(customEncodeTable) // default is built in, null resets to default |
| * .setLineLength(0) // default is none |
| * .setLineSeparator('\r', '\n') // default is CR LF, null resets to default |
| * .setPadding('=') // default is '=' |
| * .setUrlSafe(false) // default is false |
| * .get() |
| * </pre> |
| * |
| * @see Base64InputStream |
| * @see Base64OutputStream |
| * @see <a href="https://www.ietf.org/rfc/rfc2045">RFC 2045 Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies</a> |
| * @see <a href="https://datatracker.ietf.org/doc/html/rfc4648">RFC 4648 The Base16, Base32, and Base64 Data Encodings</a> |
| * @since 1.0 |
| */ |
| public class Base64 extends BaseNCodec { |
| |
| /** |
| * Builds {@link Base64} instances. |
| * |
| * <p> |
| * To configure a new instance, use a {@link Builder}. For example: |
| * </p> |
| * |
| * <pre> |
| * Base64 base64 = Base64.builder() |
| * .setCodecPolicy(CodecPolicy.LENIENT) // default is lenient, null resets to default |
| * .setEncodeTable(customEncodeTable) // default is built in, null resets to default |
| * .setLineLength(0) // default is none |
| * .setLineSeparator('\r', '\n') // default is CR LF, null resets to default |
| * .setPadding('=') // default is '=' |
| * .setUrlSafe(false) // default is false |
| * .get() |
| * </pre> |
| * |
| * @since 1.17.0 |
| */ |
| public static class Builder extends AbstractBuilder<Base64, Builder> { |
| |
| /** |
| * Constructs a new instance. |
| */ |
| public Builder() { |
| super(STANDARD_ENCODE_TABLE); |
| setDecodeTableRaw(DECODE_TABLE); |
| setEncodeTableRaw(STANDARD_ENCODE_TABLE); |
| setEncodedBlockSize(BYTES_PER_ENCODED_BLOCK); |
| setUnencodedBlockSize(BYTES_PER_UNENCODED_BLOCK); |
| } |
| |
| @Override |
| public Base64 get() { |
| return new Base64(this); |
| } |
| |
| /** |
| * Sets the format of the decoding table. This method allows to explicitly state whether a standard or URL-safe Base64 decoding is expected. This method |
| * does not modify behavior on encoding operations. For configuration of the encoding behavior, please use {@link #setUrlSafe(boolean)} method. |
| * <p> |
| * By default, the implementation uses the {@link DecodeTableFormat#MIXED} approach, allowing a seamless handling of both |
| * {@link DecodeTableFormat#URL_SAFE} and {@link DecodeTableFormat#STANDARD} base64. |
| * </p> |
| * |
| * @param format table format to be used on Base64 decoding. Use {@link DecodeTableFormat#MIXED} or null to reset to the default behavior. |
| * @return {@code this} instance. |
| * @since 1.21 |
| */ |
| public Builder setDecodeTableFormat(final DecodeTableFormat format) { |
| if (format == null) { |
| return setDecodeTableRaw(DECODE_TABLE); |
| } |
| switch (format) { |
| case STANDARD: |
| return setDecodeTableRaw(STANDARD_DECODE_TABLE); |
| case URL_SAFE: |
| return setDecodeTableRaw(URL_SAFE_DECODE_TABLE); |
| case MIXED: |
| default: |
| return setDecodeTableRaw(DECODE_TABLE); |
| } |
| } |
| |
| /** |
| * Sets the encode table. |
| * |
| * @param encodeTable The encode table with exactly 64 unique entries, null resets to the default. |
| * @return {@code this} instance. |
| * @throws IllegalArgumentException if {@code encodeTable} does not contain exactly 64 unique entries. |
| */ |
| @Override |
| public Builder setEncodeTable(final byte... encodeTable) { |
| setDecodeTableRaw(toDecodeTable(encodeTable)); |
| return super.setEncodeTable(encodeTable); |
| } |
| |
| /** |
| * Sets the URL-safe encoding policy. |
| * <p> |
| * This method does not modify behavior on decoding operations. For configuration of the decoding behavior, please use |
| * {@code Builder.setDecodeTableFormat(DecodeTableFormat)} method. |
| * </p> |
| * |
| * @param urlSafe URL-safe encoding policy. |
| * @return {@code this} instance. |
| */ |
| public Builder setUrlSafe(final boolean urlSafe) { |
| // Javadoc 8 can't find {@link #setDecodeTableFormat(DecodeTableFormat)} |
| return setEncodeTable(toUrlSafeEncodeTable(urlSafe)); |
| } |
| |
| } |
| |
| /** |
| * Enumerates the Base64 table format to be used on decoding. |
| * <p> |
| * By default, the method uses {@link DecodeTableFormat#MIXED} approach, allowing a seamless handling of both {@link DecodeTableFormat#URL_SAFE} and |
| * {@link DecodeTableFormat#STANDARD} base64 options. |
| * </p> |
| * |
| * @since 1.21 |
| */ |
| public enum DecodeTableFormat { |
| |
| /** |
| * Corresponds to the standard Base64 coding table, as specified in |
| * <a href="https://www.ietf.org/rfc/rfc2045#:~:text=Table%201%3A%20The%20Base64%20Alphabet">RFC 2045 Table 1: The Base64 Alphabet</a>. |
| */ |
| STANDARD, |
| |
| /** |
| * Corresponds to the URL-safe Base64 coding table, as specified in |
| * <a href="https://datatracker.ietf.org/doc/html/rfc4648#:~:text=Table%202%3A%20The%20%22URL%20and%20Filename%20safe%22%20Base%2064%20Alphabet">RFC |
| * 4648 Table 2: The "URL and Filename safe" Base 64 Alphabet</a>. |
| */ |
| URL_SAFE, |
| |
| /** |
| * Represents a joint approach, allowing a seamless decoding of both character sets, corresponding to either |
| * <a href="https://www.ietf.org/rfc/rfc2045#:~:text=Table%201%3A%20The%20Base64%20Alphabet">RFC 2045 Table 1: The Base64 Alphabet</a> or |
| * <a href="https://datatracker.ietf.org/doc/html/rfc4648#:~:text=Table%202%3A%20The%20%22URL%20and%20Filename%20safe%22%20Base%2064%20Alphabet">RFC |
| * 4648 Table 2: The "URL and Filename safe" Base 64 Alphabet</a>. This decoding table is used by default. |
| */ |
| MIXED |
| } |
| |
| /** |
| * BASE64 characters are 6 bits in length. |
| * They are formed by taking a block of 3 octets to form a 24-bit string, |
| * which is converted into 4 BASE64 characters. |
| */ |
| private static final int BITS_PER_ENCODED_BYTE = 6; |
| private static final int BYTES_PER_UNENCODED_BLOCK = 3; |
| private static final int BYTES_PER_ENCODED_BLOCK = 4; |
| private static final int DECODING_TABLE_LENGTH = 256; |
| |
| /** |
| * This array is a lookup table that translates 6-bit positive integer index values into their "Base64 Alphabet" equivalents as specified in |
| * <a href="https://www.ietf.org/rfc/rfc2045#:~:text=Table%201%3A%20The%20Base64%20Alphabet">RFC 2045 Table 1: The Base64 Alphabet</a>. |
| * <p> |
| * Thanks to "commons" project in ws.apache.org for this code. https://svn.apache.org/repos/asf/webservices/commons/trunk/modules/util/ |
| * </p> |
| */ |
| // @formatter:off |
| private static final byte[] STANDARD_ENCODE_TABLE = { |
| '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', '+', '/' |
| }; |
| |
| /** |
| * This is a copy of the STANDARD_ENCODE_TABLE above, but with + and / changed to - and _ to make the encoded Base64 results more URL-SAFE. This table is |
| * only used when the Base64's mode is set to URL-SAFE. |
| */ |
| // @formatter:off |
| private static final byte[] URL_SAFE_ENCODE_TABLE = { |
| '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', '-', '_' |
| }; |
| // @formatter:on |
| |
| /** |
| * This array is a lookup table that translates Unicode characters drawn from the "Base64 Alphabet" (as specified in |
| * <a href="https://www.ietf.org/rfc/rfc2045#:~:text=Table%201%3A%20The%20Base64%20Alphabet">RFC 2045 Table 1: The Base64 Alphabet</a>) into their 6-bit |
| * positive integer equivalents. Characters that are not in the Base64 or Base64 URL-safe alphabets but fall within the bounds of the array are translated |
| * to -1. |
| * <p> |
| * The characters '+' and '-' both decode to 62. '/' and '_' both decode to 63. This means decoder seamlessly handles both URL_SAFE and STANDARD base64. |
| * (The encoder, on the other hand, needs to know ahead of time what to emit). |
| * </p> |
| * <p> |
| * Thanks to "commons" project in ws.apache.org for this code. https://svn.apache.org/repos/asf/webservices/commons/trunk/modules/util/ |
| * </p> |
| */ |
| private static final byte[] DECODE_TABLE = { |
| // 0 1 2 3 4 5 6 7 8 9 A B C D E F |
| -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 00-0f |
| -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 10-1f |
| -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, 62, -1, 63, // 20-2f + - / |
| 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -1, -1, -1, // 30-3f 0-9 |
| -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, // 40-4f A-O |
| 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, 63, // 50-5f P-Z _ |
| -1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, // 60-6f a-o |
| 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51 // 70-7a p-z |
| }; |
| |
| /** |
| * This array is a lookup table that translates Unicode characters drawn from the "Base64 Alphabet" (as specified in |
| * <a href="https://www.ietf.org/rfc/rfc2045#:~:text=Table%201%3A%20The%20Base64%20Alphabet">RFC 2045 Table 1: The Base64 Alphabet</a>) into their 6-bit |
| * positive integer equivalents. Characters that are not in the Base64 alphabet but fall within the bounds of the array are translated to -1. This decoding |
| * table handles only the standard base64 characters, such as '+' and '/'. The "url-safe" characters such as '-' and '_' are not supported by the table. |
| */ |
| private static final byte[] STANDARD_DECODE_TABLE = { |
| // 0 1 2 3 4 5 6 7 8 9 A B C D E F |
| -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 00-0f |
| -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 10-1f |
| -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63, // 20-2f + / |
| 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -1, -1, -1, // 30-3f 0-9 |
| -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, // 40-4f A-O |
| 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1, // 50-5f P-Z |
| -1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, // 60-6f a-o |
| 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51 // 70-7a p-z |
| }; |
| |
| /** |
| * This array is a lookup table that translates Unicode characters drawn from the "Base64 URL-safe Alphabet" (as specified in |
| * <a href="https://datatracker.ietf.org/doc/html/rfc4648#:~:text=Table%202%3A%20The%20%22URL%20and%20Filename%20safe%22%20Base%2064%20Alphabet">RFC 4648 |
| * Table 2: The "URL and Filename safe" Base 64 Alphabet</a>) into their 6-bit positive integer equivalents. Characters that are not in the Base64 URL-safe |
| * alphabet but fall within the bounds of the array are translated to -1. This decoding table handles only the URL-safe base64 characters, such as '-' and |
| * '_'. The standard characters such as '+' and '/' are not supported by the table. |
| */ |
| private static final byte[] URL_SAFE_DECODE_TABLE = { |
| // 0 1 2 3 4 5 6 7 8 9 A B C D E F |
| -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 00-0f |
| -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 10-1f |
| -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, // 20-2f - |
| 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -1, -1, -1, // 30-3f 0-9 |
| -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, // 40-4f A-O |
| 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, 63, // 50-5f P-Z _ |
| -1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, // 60-6f a-o |
| 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51 // 70-7a p-z |
| }; |
| |
| /** |
| * Base64 uses 6-bit fields. |
| */ |
| |
| /** Mask used to extract 6 bits, used when encoding */ |
| private static final int MASK_6_BITS = 0x3f; |
| |
| // The static final fields above are used for the original static byte[] methods on Base64. |
| // The private member fields below are used with the new streaming approach, which requires |
| // some state be preserved between calls of encode() and decode(). |
| |
| /** Mask used to extract 4 bits, used when decoding final trailing character. */ |
| private static final int MASK_4_BITS = 0xf; |
| |
| /** Mask used to extract 2 bits, used when decoding final trailing character. */ |
| private static final int MASK_2_BITS = 0x3; |
| |
| /** |
| * Creates a new Builder. |
| * |
| * <p> |
| * To configure a new instance, use a {@link Builder}. For example: |
| * </p> |
| * |
| * <pre> |
| * Base64 base64 = Base64.builder() |
| * .setDecodingPolicy(CodecPolicy.LENIENT) // default is lenient, null resets to default |
| * .setEncodeTable(customEncodeTable) // default is built in, null resets to default |
| * .setLineLength(0) // default is none |
| * .setLineSeparator('\r', '\n') // default is CR LF, null resets to default |
| * .setPadding('=') // default is '=' |
| * .setUrlSafe(false) // default is false |
| * .get() |
| * </pre> |
| * |
| * @return A new Builder. |
| * @since 1.17.0 |
| */ |
| public static Builder builder() { |
| return new Builder(); |
| } |
| |
| /** |
| * Calculates a decode table for a given encode table. |
| * |
| * @param encodeTable that is used to determine decode lookup table. |
| * @return A new decode table. |
| */ |
| private static byte[] calculateDecodeTable(final byte[] encodeTable) { |
| if (encodeTable.length != STANDARD_ENCODE_TABLE.length) { |
| throw new IllegalArgumentException("encodeTable must have exactly 64 entries."); |
| } |
| final byte[] decodeTable = new byte[DECODING_TABLE_LENGTH]; |
| Arrays.fill(decodeTable, (byte) -1); |
| for (int i = 0; i < encodeTable.length; i++) { |
| final int encodedByte = encodeTable[i] & 0xff; |
| if (decodeTable[encodedByte] != -1) { |
| throw new IllegalArgumentException("encodeTable must not contain duplicate entries."); |
| } |
| decodeTable[encodedByte] = (byte) i; |
| } |
| return decodeTable; |
| } |
| |
| private static boolean contains(final byte[] bytes, final byte value) { |
| for (final byte element : bytes) { |
| if (element == value) { |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| /** |
| * Decodes Base64 data into octets. |
| * <p> |
| * This method seamlessly handles data encoded in URL-safe or normal mode. For enforcing verification against strict standard Base64 or Base64 URL-safe |
| * tables, please use {@link #decodeBase64Standard(byte[])} or {@link #decodeBase64UrlSafe(byte[])} methods respectively. This method skips unknown or |
| * unsupported bytes. |
| * </p> |
| * |
| * @param base64Data Byte array containing Base64 data. |
| * @return New array containing decoded data. |
| */ |
| public static byte[] decodeBase64(final byte[] base64Data) { |
| return new Base64().decode(base64Data); |
| } |
| |
| /** |
| * Decodes a Base64 String into octets. |
| * <p> |
| * This method seamlessly handles data encoded in URL-safe or normal mode. For enforcing verification against strict standard Base64 or Base64 URL-safe |
| * tables, please use {@link #decodeBase64Standard(String)} or {@link #decodeBase64UrlSafe(String)} methods respectively. This method skips unknown or |
| * unsupported bytes. |
| * </p> |
| * |
| * @param base64String String containing Base64 data. |
| * @return New array containing decoded data. |
| * @since 1.4 |
| */ |
| public static byte[] decodeBase64(final String base64String) { |
| return new Base64().decode(base64String); |
| } |
| |
| /** |
| * Decodes standard Base64 data into octets. |
| * <p> |
| * This implementation is aligned with the <a href="https://www.ietf.org/rfc/rfc2045#:~:text=Table%201%3A%20The%20Base64%20Alphabet">RFC 2045 Table 1: The |
| * Base64 Alphabet</a>. This method skips unknown or unsupported bytes. |
| * </p> |
| * |
| * @param base64Data Byte array containing Base64 data. |
| * @return New array containing decoded data. |
| * @since 1.21 |
| */ |
| public static byte[] decodeBase64Standard(final byte[] base64Data) { |
| return builder().setDecodeTableFormat(DecodeTableFormat.STANDARD).get().decode(base64Data); |
| } |
| |
| /** |
| * Decodes a standard Base64 String into octets. |
| * <p> |
| * This implementation is aligned with the <a href="https://www.ietf.org/rfc/rfc2045#:~:text=Table%201%3A%20The%20Base64%20Alphabet">RFC 2045 Table 1: The |
| * Base64 Alphabet</a>. This method skips unknown or unsupported characters. |
| * </p> |
| * |
| * @param base64String String containing Base64 data. |
| * @return New array containing decoded data. |
| * @since 1.21 |
| */ |
| public static byte[] decodeBase64Standard(final String base64String) { |
| return builder().setDecodeTableFormat(DecodeTableFormat.STANDARD).get().decode(base64String); |
| } |
| |
| /** |
| * Decodes URL-safe Base64 data into octets. |
| * <p> |
| * This implementation is aligned with |
| * <a href="https://datatracker.ietf.org/doc/html/rfc4648#:~:text=Table%202%3A%20The%20%22URL%20and%20Filename%20safe%22%20Base%2064%20Alphabet">RFC 4648 |
| * Table 2: The "URL and Filename safe" Base 64 Alphabet</a>. This method skips unknown or unsupported characters. |
| * </p> |
| * |
| * @param base64Data Byte array containing Base64 data. |
| * @return New array containing decoded data. |
| * @since 1.21 |
| */ |
| public static byte[] decodeBase64UrlSafe(final byte[] base64Data) { |
| return builder().setDecodeTableFormat(DecodeTableFormat.URL_SAFE).get().decode(base64Data); |
| } |
| |
| /** |
| * Decodes a URL-safe Base64 String into octets. |
| * <p> |
| * This implementation is aligned with |
| * <a href="https://datatracker.ietf.org/doc/html/rfc4648#:~:text=Table%202%3A%20The%20%22URL%20and%20Filename%20safe%22%20Base%2064%20Alphabet">RFC 4648 |
| * Table 2: The "URL and Filename safe" Base 64 Alphabet</a>. This method skips unknown or unsupported characters. |
| * </p> |
| * |
| * @param base64String String containing Base64 data. |
| * @return New array containing decoded data. |
| * @since 1.21 |
| */ |
| public static byte[] decodeBase64UrlSafe(final String base64String) { |
| return builder().setDecodeTableFormat(DecodeTableFormat.URL_SAFE).get().decode(base64String); |
| } |
| |
| /** |
| * Decodes a byte64-encoded integer according to crypto standards such as W3C's XML-Signature. |
| * |
| * @param array A byte array containing base64 character data. |
| * @return A BigInteger. |
| * @since 1.4 |
| */ |
| public static BigInteger decodeInteger(final byte[] array) { |
| return new BigInteger(1, decodeBase64(array)); |
| } |
| |
| /** |
| * Encodes binary data using the base64 algorithm but does not chunk the output. |
| * |
| * @param binaryData binary data to encode. |
| * @return byte[] containing Base64 characters in their UTF-8 representation. |
| */ |
| public static byte[] encodeBase64(final byte[] binaryData) { |
| return encodeBase64(binaryData, false); |
| } |
| |
| /** |
| * Encodes binary data using the base64 algorithm, optionally chunking the output into 76 character blocks. |
| * |
| * @param binaryData Array containing binary data to encode. |
| * @param isChunked if {@code true} this encoder will chunk the base64 output into 76 character blocks. |
| * @return Base64-encoded data. |
| * @throws IllegalArgumentException Thrown when the input array needs an output array bigger than {@link Integer#MAX_VALUE}. |
| */ |
| public static byte[] encodeBase64(final byte[] binaryData, final boolean isChunked) { |
| return encodeBase64(binaryData, isChunked, false); |
| } |
| |
| /** |
| * Encodes binary data using the base64 algorithm, optionally chunking the output into 76 character blocks. |
| * |
| * @param binaryData Array containing binary data to encode. |
| * @param isChunked if {@code true} this encoder will chunk the base64 output into 76 character blocks. |
| * @param urlSafe if {@code true} this encoder will emit - and _ instead of the usual + and / characters. <strong>No padding is added when encoding using |
| * the URL-safe alphabet.</strong> |
| * @return Base64-encoded data. |
| * @throws IllegalArgumentException Thrown when the input array needs an output array bigger than {@link Integer#MAX_VALUE}. |
| * @since 1.4 |
| */ |
| public static byte[] encodeBase64(final byte[] binaryData, final boolean isChunked, final boolean urlSafe) { |
| return encodeBase64(binaryData, isChunked, urlSafe, Integer.MAX_VALUE); |
| } |
| |
| /** |
| * Encodes binary data using the base64 algorithm, optionally chunking the output into 76 character blocks. |
| * |
| * @param binaryData Array containing binary data to encode. |
| * @param isChunked if {@code true} this encoder will chunk the base64 output into 76 character blocks. |
| * @param urlSafe if {@code true} this encoder will emit - and _ instead of the usual + and / characters. <strong>No padding is added when encoding |
| * using the URL-safe alphabet.</strong> |
| * @param maxResultSize The maximum result size to accept. |
| * @return Base64-encoded data. |
| * @throws IllegalArgumentException Thrown when the input array needs an output array bigger than maxResultSize. |
| * @since 1.4 |
| */ |
| public static byte[] encodeBase64(final byte[] binaryData, final boolean isChunked, final boolean urlSafe, final int maxResultSize) { |
| if (BinaryCodec.isEmpty(binaryData)) { |
| return binaryData; |
| } |
| // Create this so can use the super-class method |
| // Also ensures that the same roundings are performed by the ctor and the code |
| final Base64 b64 = isChunked ? new Base64(urlSafe) : new Base64(0, CHUNK_SEPARATOR, urlSafe); |
| final long len = b64.getEncodedLength(binaryData); |
| if (len > maxResultSize) { |
| throw new IllegalArgumentException( |
| "Input array too big, the output array would be bigger (" + len + ") than the specified maximum size of " + maxResultSize); |
| } |
| return b64.encode(binaryData); |
| } |
| |
| /** |
| * Encodes binary data using the base64 algorithm and chunks the encoded output into 76 character blocks |
| * |
| * @param binaryData binary data to encode. |
| * @return Base64 characters chunked in 76 character blocks. |
| */ |
| public static byte[] encodeBase64Chunked(final byte[] binaryData) { |
| return encodeBase64(binaryData, true); |
| } |
| |
| /** |
| * Encodes binary data using the base64 algorithm but does not chunk the output. |
| * <p> |
| * <strong> We changed the behavior of this method from multi-line chunking (1.4) to single-line non-chunking (1.5).</strong> |
| * </p> |
| * |
| * @param binaryData binary data to encode. |
| * @return String containing Base64 characters. |
| * @since 1.4 (NOTE: 1.4 chunked the output, whereas 1.5 does not). |
| */ |
| public static String encodeBase64String(final byte[] binaryData) { |
| return StringUtils.newStringUsAscii(encodeBase64(binaryData, false)); |
| } |
| |
| /** |
| * Encodes binary data using a URL-safe variation of the base64 algorithm but does not chunk the output. The url-safe variation emits - and _ instead of + |
| * and / characters. <strong>No padding is added.</strong> |
| * |
| * @param binaryData binary data to encode. |
| * @return byte[] containing Base64 characters in their UTF-8 representation. |
| * @since 1.4 |
| */ |
| public static byte[] encodeBase64URLSafe(final byte[] binaryData) { |
| return encodeBase64(binaryData, false, true); |
| } |
| |
| /** |
| * Encodes binary data using a URL-safe variation of the base64 algorithm but does not chunk the output. The url-safe variation emits - and _ instead of + |
| * and / characters. <strong>No padding is added.</strong> |
| * |
| * @param binaryData binary data to encode. |
| * @return String containing Base64 characters. |
| * @since 1.4 |
| */ |
| public static String encodeBase64URLSafeString(final byte[] binaryData) { |
| return StringUtils.newStringUsAscii(encodeBase64(binaryData, false, true)); |
| } |
| |
| /** |
| * Encodes to a byte64-encoded integer according to crypto standards such as W3C's XML-Signature. |
| * |
| * @param bigInteger A BigInteger. |
| * @return A byte array containing base64 character data. |
| * @throws NullPointerException if null is passed in. |
| * @since 1.4 |
| */ |
| public static byte[] encodeInteger(final BigInteger bigInteger) { |
| Objects.requireNonNull(bigInteger, "bigInteger"); |
| return encodeBase64(toUnsignedBytes(bigInteger), false); |
| } |
| |
| /** |
| * Tests a given byte array to see if it contains only valid characters within the Base64 alphabet. Currently the method treats whitespace as valid. |
| * |
| * @param arrayOctet byte array to test. |
| * @return {@code true} if all bytes are valid characters in the Base64 alphabet or if the byte array is empty; {@code false}, otherwise. |
| * @deprecated 1.5 Use {@link #isBase64(byte[])}, will be removed in 2.0. |
| */ |
| @Deprecated |
| public static boolean isArrayByteBase64(final byte[] arrayOctet) { |
| return isBase64(arrayOctet); |
| } |
| |
| /** |
| * Tests whether or not the {@code octet} is in the Base64 alphabet. |
| * <p> |
| * This method threats all characters included within standard base64 and base64url encodings as valid base64 characters. This includes the '+' and '/' |
| * (standard base64), as well as '-' and '_' (URL-safe base64) characters. For enforcing verification against strict standard Base64 or Base64 URL-safe |
| * tables, please use {@link #isBase64Standard(byte)} or {@link #isBase64Url(byte)} methods respectively. |
| * </p> |
| * |
| * @param octet The value to test. |
| * @return {@code true} if the value is defined in the Base64 alphabet, {@code false} otherwise. |
| * @since 1.4 |
| */ |
| public static boolean isBase64(final byte octet) { |
| return octet == PAD_DEFAULT || octet >= 0 && octet < DECODE_TABLE.length && DECODE_TABLE[octet] != -1; |
| } |
| |
| /** |
| * Tests a given byte array to see if it contains only valid characters within the Base64 alphabet. Currently the method treats whitespace as valid. |
| * <p> |
| * This method treats all characters included within standard base64 and base64url encodings as valid base64 characters. This includes the '+' and '/' |
| * (standard base64), as well as '-' and '_' (URL-safe base64) characters. For enforcing verification against strict standard Base64 or Base64 URL-safe |
| * tables, please use {@link #isBase64Standard(byte[])} or {@link #isBase64Url(byte[])} methods respectively. |
| * </p> |
| * |
| * @param arrayOctet byte array to test. |
| * @return {@code true} if all bytes are valid characters in the Base64 alphabet or if the byte array is empty; {@code false}, otherwise. |
| * @since 1.5 |
| */ |
| public static boolean isBase64(final byte[] arrayOctet) { |
| for (final byte element : arrayOctet) { |
| if (!isBase64(element) && !Character.isWhitespace(element)) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| /** |
| * Tests a given String to see if it contains only valid characters within the Base64 alphabet. Currently the method treats whitespace as valid. |
| * <p> |
| * This method threats all characters included within standard base64 and base64url encodings as valid base64 characters. This includes the '+' and '/' |
| * (standard base64), as well as '-' and '_' (URL-safe base64) characters. For enforcing verification against strict standard Base64 or Base64 URL-safe |
| * tables, please use {@link #isBase64Standard(String)} or {@link #isBase64Url(String)} methods respectively. |
| * </p> |
| * |
| * @param base64 String to test. |
| * @return {@code true} if all characters in the String are valid characters in the Base64 alphabet or if the String is empty; {@code false}, otherwise. |
| * @since 1.5 |
| */ |
| public static boolean isBase64(final String base64) { |
| return isBase64(StringUtils.getBytesUtf8(base64)); |
| } |
| |
| /** |
| * Tests whether or not the {@code octet} is in the standard Base64 alphabet. |
| * <p> |
| * This implementation is aligned with <a href="https://www.ietf.org/rfc/rfc2045#:~:text=Table%201%3A%20The%20Base64%20Alphabet">RFC 2045 Table 1: The |
| * Base64 Alphabet</a>. |
| * </p> |
| * |
| * @param octet The value to test. |
| * @return {@code true} if the value is defined in the standard Base64 alphabet, {@code false} otherwise. |
| * @since 1.21 |
| */ |
| public static boolean isBase64Standard(final byte octet) { |
| return octet == PAD_DEFAULT || octet >= 0 && octet < STANDARD_DECODE_TABLE.length && STANDARD_DECODE_TABLE[octet] != -1; |
| } |
| |
| /** |
| * Tests a given byte array to see if it contains only valid characters within the standard Base64 alphabet. The method treats whitespace as valid. |
| * <p> |
| * This implementation is aligned with <a href="https://www.ietf.org/rfc/rfc2045#:~:text=Table%201%3A%20The%20Base64%20Alphabet">RFC 2045 Table 1: The |
| * Base64 Alphabet</a>. |
| * </p> |
| * |
| * @param arrayOctet byte array to test. |
| * @return {@code true} if all bytes are valid characters in the standard Base64 alphabet. {@code false}, otherwise. |
| * @since 1.21 |
| */ |
| public static boolean isBase64Standard(final byte[] arrayOctet) { |
| for (final byte element : arrayOctet) { |
| if (!isBase64Standard(element) && !Character.isWhitespace(element)) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| /** |
| * Tests a given String to see if it contains only valid characters within the standard Base64 alphabet. The method treats whitespace as valid. |
| * <p> |
| * This implementation is aligned with <a href="https://www.ietf.org/rfc/rfc2045#:~:text=Table%201%3A%20The%20Base64%20Alphabet">RFC 2045 Table 1: The |
| * Base64 Alphabet</a>. |
| * </p> |
| * |
| * @param base64 String to test. |
| * @return {@code true} if all characters in the String are valid characters in the standard Base64 alphabet or if the String is empty; {@code false}, |
| * otherwise. |
| * @since 1.21 |
| */ |
| public static boolean isBase64Standard(final String base64) { |
| return isBase64Standard(StringUtils.getBytesUtf8(base64)); |
| } |
| |
| /** |
| * Tests whether or not the {@code octet} is in the URL-safe Base64 alphabet. |
| * <p> |
| * This implementation is aligned with |
| * <a href="https://datatracker.ietf.org/doc/html/rfc4648#:~:text=Table%202%3A%20The%20%22URL%20and%20Filename%20safe%22%20Base%2064%20Alphabet">RFC 4648 |
| * Table 2: The "URL and Filename safe" Base 64 Alphabet</a>. |
| * </p> |
| * |
| * @param octet The value to test. |
| * @return {@code true} if the value is defined in the URL-safe Base64 alphabet, {@code false} otherwise. |
| * @since 1.21 |
| */ |
| public static boolean isBase64Url(final byte octet) { |
| return octet == PAD_DEFAULT || octet >= 0 && octet < URL_SAFE_DECODE_TABLE.length && URL_SAFE_DECODE_TABLE[octet] != -1; |
| } |
| |
| /** |
| * Tests a given byte array to see if it contains only valid characters within the URL-safe Base64 alphabet. The method treats whitespace as valid. |
| * <p> |
| * This implementation is aligned with |
| * <a href="https://datatracker.ietf.org/doc/html/rfc4648#:~:text=Table%202%3A%20The%20%22URL%20and%20Filename%20safe%22%20Base%2064%20Alphabet">RFC 4648 |
| * Table 2: The "URL and Filename safe" Base 64 Alphabet</a>. |
| * </p> |
| * |
| * @param arrayOctet byte array to test. |
| * @return {@code true} if all bytes are valid characters in the URL-safe Base64 alphabet, {@code false}, otherwise. |
| * @since 1.21 |
| */ |
| public static boolean isBase64Url(final byte[] arrayOctet) { |
| for (final byte element : arrayOctet) { |
| if (!isBase64Url(element) && !Character.isWhitespace(element)) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| /** |
| * Tests a given String to see if it contains only valid characters within the URL-safe Base64 alphabet. The method treats whitespace as valid. |
| * <p> |
| * This implementation is aligned with |
| * <a href="https://datatracker.ietf.org/doc/html/rfc4648#:~:text=Table%202%3A%20The%20%22URL%20and%20Filename%20safe%22%20Base%2064%20Alphabet">RFC 4648 |
| * Table 2: The "URL and Filename safe" Base 64 Alphabet</a>. |
| * </p> |
| * |
| * @param base64 String to test. |
| * @return {@code true} if all characters in the String are valid characters in the URL-safe Base64 alphabet or if the String is empty; {@code false}, |
| * otherwise. |
| * @since 1.21 |
| */ |
| public static boolean isBase64Url(final String base64) { |
| return isBase64Url(StringUtils.getBytesUtf8(base64)); |
| } |
| |
| private static byte[] toDecodeTable(final byte[] encodeTable) { |
| final byte[] table = encodeTable != null ? encodeTable : STANDARD_ENCODE_TABLE; |
| if (Arrays.equals(table, STANDARD_ENCODE_TABLE) || Arrays.equals(table, URL_SAFE_ENCODE_TABLE)) { |
| return DECODE_TABLE; |
| } |
| return calculateDecodeTable(table); |
| } |
| |
| static byte[] toUrlSafeEncodeTable(final boolean urlSafe) { |
| return urlSafe ? URL_SAFE_ENCODE_TABLE : STANDARD_ENCODE_TABLE; |
| } |
| |
| /** |
| * Line separator for encoding. Not used when decoding. Only used if lineLength > 0. |
| */ |
| private final byte[] lineSeparator; |
| |
| /** |
| * Convenience variable to help us determine when our buffer is going to run out of room and needs resizing. {@code encodeSize = 4 + lineSeparator.length;} |
| */ |
| private final int encodeSize; |
| private final boolean isUrlSafe; |
| private final boolean isStandardEncodeTable; |
| |
| /** |
| * Constructs a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode. |
| * <p> |
| * When encoding the line length is 0 (no chunking), and the encoding table is STANDARD_ENCODE_TABLE. |
| * </p> |
| * <p> |
| * When decoding all variants are supported. |
| * </p> |
| */ |
| public Base64() { |
| this(0); |
| } |
| |
| /** |
| * Constructs a Base64 codec used for decoding (all modes) and encoding in the given URL-safe mode. |
| * <p> |
| * When encoding the line length is 76, the line separator is CRLF, and the encoding table is STANDARD_ENCODE_TABLE. |
| * </p> |
| * <p> |
| * When decoding all variants are supported. |
| * </p> |
| * |
| * @param urlSafe if {@code true}, URL-safe encoding is used. In most cases this should be set to {@code false}. |
| * @since 1.4 |
| * @deprecated Use {@link #builder()} and {@link Builder}. |
| */ |
| @Deprecated |
| public Base64(final boolean urlSafe) { |
| this(MIME_CHUNK_SIZE, CHUNK_SEPARATOR, urlSafe); |
| } |
| |
| private Base64(final Builder builder) { |
| super(builder); |
| final byte[] encTable = builder.getEncodeTable(); |
| if (encTable.length != STANDARD_ENCODE_TABLE.length) { |
| throw new IllegalArgumentException("encodeTable must have exactly 64 entries."); |
| } |
| if (contains(encTable, pad)) { |
| throw new IllegalArgumentException("encodeTable must not contain the padding byte."); |
| } |
| this.isStandardEncodeTable = Arrays.equals(encTable, STANDARD_ENCODE_TABLE); |
| this.isUrlSafe = Arrays.equals(encTable, URL_SAFE_ENCODE_TABLE); |
| // TODO could be simplified if there is no requirement to reject invalid line sep when length <=0 |
| // @see test case Base64Test.testConstructors() |
| if (builder.getLineSeparator().length > 0) { |
| final byte[] lineSeparatorB = builder.getLineSeparator(); |
| if (containsAlphabetOrPad(lineSeparatorB)) { |
| final String sep = StringUtils.newStringUtf8(lineSeparatorB); |
| throw new IllegalArgumentException("lineSeparator must not contain base64 characters: [" + sep + "]"); |
| } |
| if (builder.getLineLength() > 0) { // null line-sep forces no chunking rather than throwing IAE |
| this.encodeSize = BYTES_PER_ENCODED_BLOCK + lineSeparatorB.length; |
| this.lineSeparator = lineSeparatorB; |
| } else { |
| this.encodeSize = BYTES_PER_ENCODED_BLOCK; |
| this.lineSeparator = null; |
| } |
| } else { |
| this.encodeSize = BYTES_PER_ENCODED_BLOCK; |
| this.lineSeparator = null; |
| } |
| } |
| |
| /** |
| * Constructs a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode. |
| * <p> |
| * When encoding the line length is given in the constructor, the line separator is CRLF, and the encoding table is STANDARD_ENCODE_TABLE. |
| * </p> |
| * <p> |
| * Line lengths that aren't multiples of 4 will still essentially end up being multiples of 4 in the encoded data. |
| * </p> |
| * <p> |
| * When decoding all variants are supported. |
| * </p> |
| * |
| * @param lineLength Each line of encoded data will be at most of the given length (rounded down to the nearest multiple of 4). If lineLength <= 0, then |
| * the output will not be divided into lines (chunks). Ignored when decoding. |
| * @since 1.4 |
| * @deprecated Use {@link #builder()} and {@link Builder}. |
| */ |
| @Deprecated |
| public Base64(final int lineLength) { |
| this(lineLength, CHUNK_SEPARATOR); |
| } |
| |
| /** |
| * Constructs a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode. |
| * <p> |
| * When encoding the line length and line separator are given in the constructor, and the encoding table is STANDARD_ENCODE_TABLE. |
| * </p> |
| * <p> |
| * Line lengths that aren't multiples of 4 will still essentially end up being multiples of 4 in the encoded data. |
| * </p> |
| * <p> |
| * When decoding all variants are supported. |
| * </p> |
| * |
| * @param lineLength Each line of encoded data will be at most of the given length (rounded down to the nearest multiple of 4). If lineLength <= 0, |
| * then the output will not be divided into lines (chunks). Ignored when decoding. |
| * @param lineSeparator Each line of encoded data will end with this sequence of bytes. |
| * @throws IllegalArgumentException Thrown when the provided lineSeparator included some base64 characters. |
| * @since 1.4 |
| * @deprecated Use {@link #builder()} and {@link Builder}. |
| */ |
| @Deprecated |
| public Base64(final int lineLength, final byte[] lineSeparator) { |
| this(lineLength, lineSeparator, false); |
| } |
| |
| /** |
| * Constructs a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode. |
| * <p> |
| * When encoding the line length and line separator are given in the constructor, and the encoding table is STANDARD_ENCODE_TABLE. |
| * </p> |
| * <p> |
| * Line lengths that aren't multiples of 4 will still essentially end up being multiples of 4 in the encoded data. |
| * </p> |
| * <p> |
| * When decoding all variants are supported. |
| * </p> |
| * |
| * @param lineLength Each line of encoded data will be at most of the given length (rounded down to the nearest multiple of 4). If lineLength <= 0, |
| * then the output will not be divided into lines (chunks). Ignored when decoding. |
| * @param lineSeparator Each line of encoded data will end with this sequence of bytes. |
| * @param urlSafe Instead of emitting '+' and '/' we emit '-' and '_' respectively. urlSafe is only applied to encode operations. Decoding seamlessly |
| * handles both modes. <strong>No padding is added when using the URL-safe alphabet.</strong> |
| * @throws IllegalArgumentException Thrown when the {@code lineSeparator} contains Base64 characters. |
| * @since 1.4 |
| * @deprecated Use {@link #builder()} and {@link Builder}. |
| */ |
| @Deprecated |
| public Base64(final int lineLength, final byte[] lineSeparator, final boolean urlSafe) { |
| this(builder().setLineLength(lineLength).setLineSeparator(lineSeparator != null ? lineSeparator : EMPTY_BYTE_ARRAY).setPadding(PAD_DEFAULT) |
| .setEncodeTableRaw(toUrlSafeEncodeTable(urlSafe)).setDecodingPolicy(DECODING_POLICY_DEFAULT)); |
| } |
| |
| /** |
| * Constructs a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode. |
| * <p> |
| * When encoding the line length and line separator are given in the constructor, and the encoding table is STANDARD_ENCODE_TABLE. |
| * </p> |
| * <p> |
| * Line lengths that aren't multiples of 4 will still essentially end up being multiples of 4 in the encoded data. |
| * </p> |
| * <p> |
| * When decoding all variants are supported. |
| * </p> |
| * |
| * @param lineLength Each line of encoded data will be at most of the given length (rounded down to the nearest multiple of 4). If lineLength <= 0, |
| * then the output will not be divided into lines (chunks). Ignored when decoding. |
| * @param lineSeparator Each line of encoded data will end with this sequence of bytes. |
| * @param urlSafe Instead of emitting '+' and '/' we emit '-' and '_' respectively. urlSafe is only applied to encode operations. Decoding seamlessly |
| * handles both modes. <strong>No padding is added when using the URL-safe alphabet.</strong> |
| * @param decodingPolicy The decoding policy. |
| * @throws IllegalArgumentException Thrown when the {@code lineSeparator} contains Base64 characters. |
| * @since 1.15 |
| * @deprecated Use {@link #builder()} and {@link Builder}. |
| */ |
| @Deprecated |
| public Base64(final int lineLength, final byte[] lineSeparator, final boolean urlSafe, final CodecPolicy decodingPolicy) { |
| this(builder().setLineLength(lineLength).setLineSeparator(lineSeparator).setPadding(PAD_DEFAULT).setEncodeTableRaw(toUrlSafeEncodeTable(urlSafe)) |
| .setDecodingPolicy(decodingPolicy)); |
| } |
| |
| /** |
| * <p> |
| * Decodes all of the provided data, starting at inPos, for inAvail bytes. Should be called at least twice: once with the data to decode, and once with |
| * inAvail set to "-1" to alert decoder that EOF has been reached. The "-1" call is not necessary when decoding, but it doesn't hurt, either. |
| * </p> |
| * <p> |
| * Ignores all non-base64 characters. This is how chunked (for example 76 character) data is handled, since CR and LF are silently ignored, but has |
| * implications for other bytes, too. This method subscribes to the garbage-in, garbage-out philosophy: it will not check the provided data for validity. |
| * </p> |
| * <p> |
| * Thanks to "commons" project in ws.apache.org for the bitwise operations, and general approach. |
| * https://svn.apache.org/repos/asf/webservices/commons/trunk/modules/util/ |
| * </p> |
| * |
| * @param input byte[] array of ASCII data to base64 decode. |
| * @param inPos Position to start reading data from. |
| * @param inAvail Amount of bytes available from input for decoding. |
| * @param context The context to be used. |
| */ |
| @Override |
| void decode(final byte[] input, int inPos, final int inAvail, final Context context) { |
| if (context.eof) { |
| return; |
| } |
| if (inAvail < 0) { |
| context.eof = true; |
| } |
| final int decodeSize = this.encodeSize - 1; |
| for (int i = 0; i < inAvail; i++) { |
| final int b = input[inPos++] & 0xff; |
| if (b == (pad & 0xff)) { |
| // We're done. |
| context.eof = true; |
| break; |
| } |
| final byte[] buffer = ensureBufferSize(decodeSize, context); |
| if (b < decodeTable.length) { |
| final int result = decodeTable[b]; |
| if (result >= 0) { |
| context.modulus = (context.modulus + 1) % BYTES_PER_ENCODED_BLOCK; |
| context.ibitWorkArea = (context.ibitWorkArea << BITS_PER_ENCODED_BYTE) + result; |
| if (context.modulus == 0) { |
| buffer[context.pos++] = (byte) (context.ibitWorkArea >> 16 & MASK_8BITS); |
| buffer[context.pos++] = (byte) (context.ibitWorkArea >> 8 & MASK_8BITS); |
| buffer[context.pos++] = (byte) (context.ibitWorkArea & MASK_8BITS); |
| } |
| } |
| } |
| } |
| |
| // Two forms of EOF as far as base64 decoder is concerned: actual |
| // EOF (-1) and first time '=' character is encountered in stream. |
| // This approach makes the '=' padding characters completely optional. |
| if (context.eof && context.modulus != 0) { |
| final byte[] buffer = ensureBufferSize(decodeSize, context); |
| |
| // We have some spare bits remaining |
| // Output all whole multiples of 8 bits and ignore the rest |
| switch (context.modulus) { |
| // case 0 : // impossible, as excluded above |
| case 1 : // 6 bits - either ignore entirely, or raise an exception |
| validateTrailingCharacter(); |
| break; |
| case 2 : // 12 bits = 8 + 4 |
| validateCharacter(MASK_4_BITS, context); |
| context.ibitWorkArea = context.ibitWorkArea >> 4; // dump the extra 4 bits |
| buffer[context.pos++] = (byte) (context.ibitWorkArea & MASK_8BITS); |
| break; |
| case 3 : // 18 bits = 8 + 8 + 2 |
| validateCharacter(MASK_2_BITS, context); |
| context.ibitWorkArea = context.ibitWorkArea >> 2; // dump 2 bits |
| buffer[context.pos++] = (byte) (context.ibitWorkArea >> 8 & MASK_8BITS); |
| buffer[context.pos++] = (byte) (context.ibitWorkArea & MASK_8BITS); |
| break; |
| default: |
| throw new IllegalStateException("Impossible modulus " + context.modulus); |
| } |
| } |
| } |
| |
| /** |
| * <p> |
| * Encodes all of the provided data, starting at inPos, for inAvail bytes. Must be called at least twice: once with the data to encode, and once with |
| * inAvail set to "-1" to alert encoder that EOF has been reached, to flush last remaining bytes (if not multiple of 3). |
| * </p> |
| * <p> |
| * <strong>No padding is added when encoding using the URL-safe alphabet.</strong> |
| * </p> |
| * <p> |
| * Thanks to "commons" project in ws.apache.org for the bitwise operations, and general approach. |
| * https://svn.apache.org/repos/asf/webservices/commons/trunk/modules/util/ |
| * </p> |
| * |
| * @param in byte[] array of binary data to base64 encode. |
| * @param inPos Position to start reading data from. |
| * @param inAvail Amount of bytes available from input for encoding. |
| * @param context The context to be used. |
| */ |
| @Override |
| void encode(final byte[] in, int inPos, final int inAvail, final Context context) { |
| if (context.eof) { |
| return; |
| } |
| // inAvail < 0 is how we're informed of EOF in the underlying data we're |
| // encoding. |
| if (inAvail < 0) { |
| context.eof = true; |
| if (0 == context.modulus && lineLength == 0) { |
| return; // no leftovers to process and not using chunking |
| } |
| final byte[] buffer = ensureBufferSize(encodeSize, context); |
| final int savedPos = context.pos; |
| switch (context.modulus) { // 0-2 |
| case 0 : // nothing to do here |
| break; |
| case 1 : // 8 bits = 6 + 2 |
| // top 6 bits: |
| buffer[context.pos++] = encodeTable[context.ibitWorkArea >> 2 & MASK_6_BITS]; |
| // remaining 2: |
| buffer[context.pos++] = encodeTable[context.ibitWorkArea << 4 & MASK_6_BITS]; |
| // URL-SAFE skips the padding to further reduce size. |
| if (isStandardEncodeTable) { |
| buffer[context.pos++] = pad; |
| buffer[context.pos++] = pad; |
| } |
| break; |
| |
| case 2 : // 16 bits = 6 + 6 + 4 |
| buffer[context.pos++] = encodeTable[context.ibitWorkArea >> 10 & MASK_6_BITS]; |
| buffer[context.pos++] = encodeTable[context.ibitWorkArea >> 4 & MASK_6_BITS]; |
| buffer[context.pos++] = encodeTable[context.ibitWorkArea << 2 & MASK_6_BITS]; |
| // URL-SAFE skips the padding to further reduce size. |
| if (isStandardEncodeTable) { |
| buffer[context.pos++] = pad; |
| } |
| break; |
| default: |
| throw new IllegalStateException("Impossible modulus " + context.modulus); |
| } |
| context.currentLinePos += context.pos - savedPos; // keep track of current line position |
| // if currentPos == 0 we are at the start of a line, so don't add CRLF |
| if (lineLength > 0 && context.currentLinePos > 0) { |
| System.arraycopy(lineSeparator, 0, buffer, context.pos, lineSeparator.length); |
| context.pos += lineSeparator.length; |
| } |
| } else { |
| for (int i = 0; i < inAvail; i++) { |
| final byte[] buffer = ensureBufferSize(encodeSize, context); |
| context.modulus = (context.modulus + 1) % BYTES_PER_UNENCODED_BLOCK; |
| int b = in[inPos++]; |
| if (b < 0) { |
| b += 256; |
| } |
| context.ibitWorkArea = (context.ibitWorkArea << 8) + b; // BITS_PER_BYTE |
| if (0 == context.modulus) { // 3 bytes = 24 bits = 4 * 6 bits to extract |
| buffer[context.pos++] = encodeTable[context.ibitWorkArea >> 18 & MASK_6_BITS]; |
| buffer[context.pos++] = encodeTable[context.ibitWorkArea >> 12 & MASK_6_BITS]; |
| buffer[context.pos++] = encodeTable[context.ibitWorkArea >> 6 & MASK_6_BITS]; |
| buffer[context.pos++] = encodeTable[context.ibitWorkArea & MASK_6_BITS]; |
| context.currentLinePos += BYTES_PER_ENCODED_BLOCK; |
| if (lineLength > 0 && lineLength <= context.currentLinePos) { |
| System.arraycopy(lineSeparator, 0, buffer, context.pos, lineSeparator.length); |
| context.pos += lineSeparator.length; |
| context.currentLinePos = 0; |
| } |
| } |
| } |
| } |
| } |
| |
| /** |
| * Gets the line separator (for testing only). |
| * |
| * @return The line separator. |
| */ |
| byte[] getLineSeparator() { |
| return lineSeparator; |
| } |
| |
| /** |
| * Returns whether or not the {@code octet} is in the Base64 alphabet. |
| * |
| * @param octet The value to test. |
| * @return {@code true} if the value is defined in the Base64 alphabet {@code false} otherwise. |
| */ |
| @Override |
| protected boolean isInAlphabet(final byte octet) { |
| final int value = octet & 0xff; |
| return value < decodeTable.length && decodeTable[value] != -1; |
| } |
| |
| /** |
| * Returns our current encode mode. True if we're URL-safe, false otherwise. |
| * |
| * @return true if we're in URL-safe mode, false otherwise. |
| * @since 1.4 |
| */ |
| public boolean isUrlSafe() { |
| return isUrlSafe; |
| } |
| |
| /** |
| * Validates whether decoding the final trailing character is possible in the context of the set of possible Base64 values. |
| * <p> |
| * The character is valid if the lower bits within the provided mask are zero. This is used to test the final trailing base-64 digit is zero in the bits |
| * that will be discarded. |
| * </p> |
| * |
| * @param emptyBitsMask The mask of the lower bits that should be empty. |
| * @param context The context to be used. |
| * @throws IllegalArgumentException if the bits being checked contain any non-zero value. |
| */ |
| private void validateCharacter(final int emptyBitsMask, final Context context) { |
| if (isStrictDecoding() && (context.ibitWorkArea & emptyBitsMask) != 0) { |
| throw new IllegalArgumentException("Strict decoding: Last encoded character (before the paddings if any) is a valid " + |
| "Base64 alphabet but not a possible encoding. Expected the discarded bits from the character to be zero."); |
| } |
| } |
| |
| /** |
| * Validates whether decoding allows an entire final trailing character that cannot be used for a complete byte. |
| * |
| * @throws IllegalArgumentException if strict decoding is enabled. |
| */ |
| private void validateTrailingCharacter() { |
| if (isStrictDecoding()) { |
| throw new IllegalArgumentException("Strict decoding: Last encoded character (before the paddings if any) is a valid " + |
| "Base64 alphabet but not a possible encoding. Decoding requires at least two trailing 6-bit characters to create bytes."); |
| } |
| } |
| |
| } |
