From 0c8c9ad976879f7c90f9915a60845ccb0cdb337d Mon Sep 17 00:00:00 2001
From: manuel
+ * This class implements section 6.8. Base64 Content-Transfer-Encoding from RFC 2045 Multipurpose
+ * Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies by Freed and Borenstein.
+ *
+ * The class can be parameterized in the following manner with various constructors:
+ *
+ *
+ *
+ * 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). + *
+ *+ * This class is thread-safe. + *
+ * + * @see RFC 2045 + * @since 1.0 + * @version $Id$ + */ +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; + + /** + * Chunk separator per RFC 2045 section 2.1. + * + *+ * N.B. The next major release may break compatibility and make this field private. + *
+ * + * @see RFC 2045 section 2.1 + */ + static final byte[] CHUNK_SEPARATOR = {'\r', '\n'}; + + /** + * 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 = { + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, 62, -1, 63, 52, 53, 54, + 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -1, -1, -1, -1, 0, 1, 2, 3, 4, + 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, + 24, 25, -1, -1, -1, -1, 63, -1, 26, 27, 28, 29, 30, 31, 32, 33, 34, + 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51 + }; + + /** + * Base64 uses 6-bit fields. + */ + /** Mask used to extract 6 bits, used when encoding */ + private static final int MASK_6BITS = 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(). + + /** + * 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. + *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.
+ * encodeSize = 4 + lineSeparator.length;
+ */
+ private final int encodeSize;
+
+ /**
+ * Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode.
+ * + * When encoding the line length is 0 (no chunking), and the encoding table is STANDARD_ENCODE_TABLE. + *
+ * + *+ * When decoding all variants are supported. + *
+ */ + public Base64() { + this(0); + } + + /** + * Creates a Base64 codec used for decoding (all modes) and encoding in the given URL-safe mode. + *+ * When encoding the line length is 76, the line separator is CRLF, and the encoding table is + * STANDARD_ENCODE_TABLE. + *
+ * + *+ * When decoding all variants are supported. + *
+ * + * @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. + *+ * When encoding the line length is given in the constructor, the line separator is CRLF, and the encoding table is + * STANDARD_ENCODE_TABLE. + *
+ *+ * Line lengths that aren't multiples of 4 will still essentially end up being multiples of 4 in the encoded data. + *
+ *+ * When decoding all variants are supported. + *
+ * + * @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. + *+ * When encoding the line length and line separator are given in the constructor, and the encoding table is + * STANDARD_ENCODE_TABLE. + *
+ *+ * Line lengths that aren't multiples of 4 will still essentially end up being multiples of 4 in the encoded data. + *
+ *+ * When decoding all variants are supported. + *
+ * + * @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. + *+ * When encoding the line length and line separator are given in the constructor, and the encoding table is + * STANDARD_ENCODE_TABLE. + *
+ *+ * Line lengths that aren't multiples of 4 will still essentially end up being multiples of 4 in the encoded data. + *
+ *+ * When decoding all variants are supported. + *
+ * + * @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. + * Note: no padding is added when using the URL-safe alphabet. + * @throws IllegalArgumentException + * The provided lineSeparator included some base64 characters. That's not going to work! + * @since 1.4 + */ + public Base64(final int lineLength, final byte[] lineSeparator, final boolean urlSafe) { + super(BYTES_PER_UNENCODED_BLOCK, BYTES_PER_ENCODED_BLOCK, + lineLength, + lineSeparator == null ? 0 : lineSeparator.length); + // 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 = new byte[lineSeparator.length]; + System.arraycopy(lineSeparator, 0, this.lineSeparator, 0, lineSeparator.length); + } 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; + } + + /** + * 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; + } + + /** + *+ * 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). + *
+ *Note: no padding is added when encoding using the URL-safe alphabet.
+ *+ * 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/ + *
+ * + * @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; + } + } + } + } + } + + /** + *+ * 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. + *
+ *+ * 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. + *
+ *+ * 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/ + *
+ * + * @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 encoding. + * @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; + } else { + 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 - ignore entirely + // TODO not currently tested; perhaps it is impossible? + break; + case 2 : // 12 bits = 8 + 4 + 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 + 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); + } + } + } + + /** + * 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 theoctet 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 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));
+ }
+
+ /**
+ * 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 (int i = 0; i < arrayOctet.length; i++) {
+ if (!isBase64(arrayOctet[i]) && !isWhiteSpace(arrayOctet[i])) {
+ return false;
+ }
+ }
+ return true;
+ }
+
+ /**
+ * 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 but does not chunk the output.
+ *
+ * NOTE: We changed the behaviour 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.newStringUtf8(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.
+ * Note: no padding is added.
+ * @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.
+ * Note: no padding is added.
+ * @param binaryData
+ * binary data to encode
+ * @return String containing Base64 characters
+ * @since 1.4
+ */
+ public static String encodeBase64URLSafeString(final byte[] binaryData) {
+ return StringUtils.newStringUtf8(encodeBase64(binaryData, false, true));
+ }
+
+ /**
+ * 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, 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.
+ * Note: no padding is added when encoding using the URL-safe alphabet.
+ * @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.
+ * Note: no padding is added when encoding using the URL-safe alphabet.
+ * @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);
+ }
+
+ /**
+ * Decodes a Base64 String into octets
+ *
+ * @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);
+ }
+
+ /**
+ * Decodes Base64 data into octets
+ *
+ * @param base64Data
+ * Byte array containing Base64 data
+ * @return Array containing decoded data.
+ */
+ public static byte[] decodeBase64(final byte[] base64Data) {
+ return new Base64().decode(base64Data);
+ }
+
+ // Implementation of the Encoder Interface
+
+ // 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 to a byte64-encoded integer according to crypto standards such as W3C's XML-Signature
+ *
+ * @param bigInt
+ * 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 bigInt) {
+ if (bigInt == null) {
+ throw new NullPointerException("encodeInteger called with null parameter");
+ }
+ return encodeBase64(toIntegerBytes(bigInt), false);
+ }
+
+ /**
+ * Returns a byte-array representation of a BigInteger without sign bit.
+ *
+ * @param bigInt
+ * 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;
+ }
+
+ /**
+ * Returns whether or not the 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;
+ }
+
+}
--
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