| /* |
| * 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 |
| * |
| * 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 org.apache.commons.codec.binary; |
| |
| import java.math.BigInteger; |
| import java.util.Objects; |
| |
| import org.apache.commons.codec.CodecPolicy; |
| |
| /** |
| * Provides Base64 encoding and decoding as defined by <a href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045</a>. |
| * |
| * <p> |
| * This class implements section <cite>6.8. Base64 Content-Transfer-Encoding</cite> from RFC 2045 <cite>Multipurpose |
| * Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies</cite> by Freed and Borenstein. |
| * </p> |
| * <p> |
| * The class can be parameterized in the following manner with various constructors: |
| * </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 ("\r\n")</li> |
| * </ul> |
| * <p> |
| * The URL-safe parameter is only applied to encode operations. Decoding seamlessly handles both modes. |
| * </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> |
| * |
| * @see <a href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045</a> |
| * @since 1.0 |
| */ |
| public class Base64 extends BaseNCodec { |
| |
| /** |
| * BASE32 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; |
| |
| /** |
| * This array is a lookup table that translates 6-bit positive integer index values into their "Base64 Alphabet" |
| * equivalents as specified in Table 1 of RFC 2045. |
| * |
| * Thanks to "commons" project in ws.apache.org for this code. |
| * http://svn.apache.org/repos/asf/webservices/commons/trunk/modules/util/ |
| */ |
| 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. |
| */ |
| 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', '-', '_' |
| }; |
| |
| /** |
| * This array is a lookup table that translates 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 translated to -1. |
| * |
| * Note: '+' 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). |
| * |
| * Thanks to "commons" project in ws.apache.org for this code. |
| * http://svn.apache.org/repos/asf/webservices/commons/trunk/modules/util/ |
| */ |
| 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 |
| }; |
| |
| /** |
| * Base64 uses 6-bit fields. |
| */ |
| /** Mask used to extract 6 bits, used when encoding */ |
| private static final int MASK_6BITS = 0x3f; |
| /** Mask used to extract 4 bits, used when decoding final trailing character. */ |
| private static final int MASK_4BITS = 0xf; |
| /** Mask used to extract 2 bits, used when decoding final trailing character. */ |
| private static final int MASK_2BITS = 0x3; |
| |
| // 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(). |
| |
| /** |
| * Decodes Base64 data into octets. |
| * <p> |
| * <b>Note:</b> this method seamlessly handles data encoded in URL-safe or normal mode. |
| * </p> |
| * |
| * @param base64Data |
| * Byte array containing Base64 data |
| * @return Array containing decoded data. |
| */ |
| public static byte[] decodeBase64(final byte[] base64Data) { |
| return new Base64().decode(base64Data); |
| } |
| |
| /** |
| * Decodes a Base64 String into octets. |
| * <p> |
| * <b>Note:</b> this method seamlessly handles data encoded in URL-safe or normal mode. |
| * </p> |
| * |
| * @param base64String |
| * String containing Base64 data |
| * @return Array containing decoded data. |
| * @since 1.4 |
| */ |
| public static byte[] decodeBase64(final String base64String) { |
| return new Base64().decode(base64String); |
| } |
| |
| // Implementation of integer encoding used for crypto |
| /** |
| * Decodes a byte64-encoded integer according to crypto standards such as W3C's XML-Signature. |
| * |
| * @param pArray |
| * a byte array containing base64 character data |
| * @return A BigInteger |
| * @since 1.4 |
| */ |
| public static BigInteger decodeInteger(final byte[] pArray) { |
| return new BigInteger(1, decodeBase64(pArray)); |
| } |
| |
| /** |
| * 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. |
| * <b>Note: no padding is added when encoding using the URL-safe alphabet.</b> |
| * @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. |
| * <b>Note: no padding is added when encoding using the URL-safe alphabet.</b> |
| * @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 (binaryData == null || binaryData.length == 0) { |
| 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. |
| * |
| * NOTE: We changed the behavior of this method from multi-line chunking (commons-codec-1.4) to |
| * single-line non-chunking (commons-codec-1.5). |
| * |
| * @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. |
| * <b>Note: no padding is added.</b> |
| * @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. |
| * <b>Note: no padding is added.</b> |
| * @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(toIntegerBytes(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); |
| } |
| |
| /** |
| * Returns whether or not the {@code octet} is in the base 64 alphabet. |
| * |
| * @param octet |
| * The value to test |
| * @return {@code true} if the value is defined in the the base 64 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. |
| * |
| * @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) && !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. |
| * |
| * @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)); |
| } |
| |
| /** |
| * Returns a byte-array representation of a {@code BigInteger} without sign bit. |
| * |
| * @param bigInt |
| * {@code BigInteger} to be converted |
| * @return a byte array representation of the BigInteger parameter |
| */ |
| static byte[] toIntegerBytes(final BigInteger bigInt) { |
| int bitlen = bigInt.bitLength(); |
| // round bitlen |
| bitlen = ((bitlen + 7) >> 3) << 3; |
| final byte[] bigBytes = bigInt.toByteArray(); |
| |
| if (((bigInt.bitLength() % 8) != 0) && (((bigInt.bitLength() / 8) + 1) == (bitlen / 8))) { |
| return bigBytes; |
| } |
| // set up params for copying everything but sign bit |
| int startSrc = 0; |
| int len = bigBytes.length; |
| |
| // if bigInt is exactly byte-aligned, just skip signbit in copy |
| if ((bigInt.bitLength() % 8) == 0) { |
| startSrc = 1; |
| len--; |
| } |
| final int startDst = bitlen / 8 - len; // to pad w/ nulls as per spec |
| final byte[] resizedBytes = new byte[bitlen / 8]; |
| System.arraycopy(bigBytes, startSrc, resizedBytes, startDst, len); |
| return resizedBytes; |
| } |
| |
| /** |
| * Encode table to use: either STANDARD or URL_SAFE. Note: the DECODE_TABLE above remains static because it is able |
| * to decode both STANDARD and URL_SAFE streams, but the encodeTable must be a member variable so we can switch |
| * between the two modes. |
| */ |
| private final byte[] encodeTable; |
| |
| // Only one decode table currently; keep for consistency with Base32 code |
| private final byte[] decodeTable = DECODE_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 decodeSize = 3 + lineSeparator.length;} |
| */ |
| private final int decodeSize; |
| |
| /** |
| * 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; |
| |
| /** |
| * Creates 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); |
| } |
| |
| /** |
| * Creates 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 |
| */ |
| public Base64(final boolean urlSafe) { |
| this(MIME_CHUNK_SIZE, CHUNK_SEPARATOR, urlSafe); |
| } |
| |
| /** |
| * Creates 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 nearest multiple of |
| * 4). If lineLength <= 0, then the output will not be divided into lines (chunks). Ignored when |
| * decoding. |
| * @since 1.4 |
| */ |
| public Base64(final int lineLength) { |
| this(lineLength, CHUNK_SEPARATOR); |
| } |
| |
| /** |
| * Creates 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 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 |
| */ |
| public Base64(final int lineLength, final byte[] lineSeparator) { |
| this(lineLength, lineSeparator, false); |
| } |
| |
| /** |
| * Creates 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 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. |
| * <b>Note: no padding is added when using the URL-safe alphabet.</b> |
| * @throws IllegalArgumentException |
| * Thrown when the {@code lineSeparator} contains Base64 characters. |
| * @since 1.4 |
| */ |
| public Base64(final int lineLength, final byte[] lineSeparator, final boolean urlSafe) { |
| this(lineLength, lineSeparator, urlSafe, DECODING_POLICY_DEFAULT); |
| } |
| |
| /** |
| * Creates 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 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. |
| * <b>Note: no padding is added when using the URL-safe alphabet.</b> |
| * @param decodingPolicy The decoding policy. |
| * @throws IllegalArgumentException |
| * Thrown when the {@code lineSeparator} contains Base64 characters. |
| * @since 1.15 |
| */ |
| public Base64(final int lineLength, final byte[] lineSeparator, final boolean urlSafe, |
| final CodecPolicy decodingPolicy) { |
| super(BYTES_PER_UNENCODED_BLOCK, BYTES_PER_ENCODED_BLOCK, |
| lineLength, |
| lineSeparator == null ? 0 : lineSeparator.length, |
| PAD_DEFAULT, |
| decodingPolicy); |
| // TODO could be simplified if there is no requirement to reject invalid line sep when length <=0 |
| // @see test case Base64Test.testConstructors() |
| if (lineSeparator != null) { |
| if (containsAlphabetOrPad(lineSeparator)) { |
| final String sep = StringUtils.newStringUtf8(lineSeparator); |
| throw new IllegalArgumentException("lineSeparator must not contain base64 characters: [" + sep + "]"); |
| } |
| if (lineLength > 0){ // null line-sep forces no chunking rather than throwing IAE |
| this.encodeSize = BYTES_PER_ENCODED_BLOCK + lineSeparator.length; |
| this.lineSeparator = lineSeparator.clone(); |
| } else { |
| this.encodeSize = BYTES_PER_ENCODED_BLOCK; |
| this.lineSeparator = null; |
| } |
| } else { |
| this.encodeSize = BYTES_PER_ENCODED_BLOCK; |
| this.lineSeparator = null; |
| } |
| this.decodeSize = this.encodeSize - 1; |
| this.encodeTable = urlSafe ? URL_SAFE_ENCODE_TABLE : STANDARD_ENCODE_TABLE; |
| } |
| |
| // Implementation of the Encoder Interface |
| |
| /** |
| * <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 (e.g. 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. |
| * http://svn.apache.org/repos/asf/webservices/commons/trunk/modules/util/ |
| * </p> |
| * |
| * @param in |
| * 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[] in, int inPos, final int inAvail, final Context context) { |
| if (context.eof) { |
| return; |
| } |
| if (inAvail < 0) { |
| context.eof = true; |
| } |
| for (int i = 0; i < inAvail; i++) { |
| final byte[] buffer = ensureBufferSize(decodeSize, context); |
| final byte b = in[inPos++]; |
| if (b == pad) { |
| // We're done. |
| context.eof = true; |
| break; |
| } |
| if (b >= 0 && b < DECODE_TABLE.length) { |
| final int result = DECODE_TABLE[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_4BITS, 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_2BITS, 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><b>Note: no padding is added when encoding using the URL-safe alphabet.</b></p> |
| * <p> |
| * Thanks to "commons" project in ws.apache.org for the bitwise operations, and general approach. |
| * http://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_6BITS]; |
| // remaining 2: |
| buffer[context.pos++] = encodeTable[(context.ibitWorkArea << 4) & MASK_6BITS]; |
| // URL-SAFE skips the padding to further reduce size. |
| if (encodeTable == STANDARD_ENCODE_TABLE) { |
| buffer[context.pos++] = pad; |
| buffer[context.pos++] = pad; |
| } |
| break; |
| |
| case 2 : // 16 bits = 6 + 6 + 4 |
| buffer[context.pos++] = encodeTable[(context.ibitWorkArea >> 10) & MASK_6BITS]; |
| buffer[context.pos++] = encodeTable[(context.ibitWorkArea >> 4) & MASK_6BITS]; |
| buffer[context.pos++] = encodeTable[(context.ibitWorkArea << 2) & MASK_6BITS]; |
| // URL-SAFE skips the padding to further reduce size. |
| if (encodeTable == STANDARD_ENCODE_TABLE) { |
| 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_6BITS]; |
| buffer[context.pos++] = encodeTable[(context.ibitWorkArea >> 12) & MASK_6BITS]; |
| buffer[context.pos++] = encodeTable[(context.ibitWorkArea >> 6) & MASK_6BITS]; |
| buffer[context.pos++] = encodeTable[context.ibitWorkArea & MASK_6BITS]; |
| 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; |
| } |
| } |
| } |
| } |
| } |
| |
| /** |
| * 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 the Base64 alphabet {@code false} otherwise. |
| */ |
| @Override |
| protected boolean isInAlphabet(final byte octet) { |
| return octet >= 0 && octet < decodeTable.length && decodeTable[octet] != -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 this.encodeTable == URL_SAFE_ENCODE_TABLE; |
| } |
| |
| /** |
| * Validates whether decoding the final trailing character is possible in the context |
| * of the set of possible base 64 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. |
| * |
| * @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 " + |
| "base 64 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 " + |
| "base 64 alphabet but not a possible encoding. " + |
| "Decoding requires at least two trailing 6-bit characters to create bytes."); |
| } |
| } |
| |
| } |