public class Base32 extends BaseNCodec
The class can be parameterized in the following manner with various constructors:
This class operates directly on byte streams, and not character streams.
This class is thread-safe.
BaseNCodec.Context
Modifier and Type | Field and Description |
---|---|
private static int |
BITS_PER_ENCODED_BYTE
BASE32 characters are 5 bits in length.
|
private static int |
BYTES_PER_ENCODED_BLOCK |
private static int |
BYTES_PER_UNENCODED_BLOCK |
private static byte[] |
DECODE_TABLE
This array is a lookup table that translates Unicode characters drawn from the "Base32 Alphabet" (as specified
in Table 3 of RFC 4648) into their 5-bit positive integer equivalents.
|
private int |
decodeSize
Convenience variable to help us determine when our buffer is going to run out of room and needs resizing.
|
private byte[] |
decodeTable
Decode table to use.
|
private static byte[] |
ENCODE_TABLE
This array is a lookup table that translates 5-bit positive integer index values into their "Base32 Alphabet"
equivalents as specified in Table 3 of RFC 4648.
|
private int |
encodeSize
Convenience variable to help us determine when our buffer is going to run out of room and needs resizing.
|
private byte[] |
encodeTable
Encode table to use.
|
private static byte[] |
HEX_DECODE_TABLE
This array is a lookup table that translates Unicode characters drawn from the "Base32 Hex Alphabet" (as
specified in Table 4 of RFC 4648) into their 5-bit positive integer equivalents.
|
private static byte[] |
HEX_ENCODE_TABLE
This array is a lookup table that translates 5-bit positive integer index values into their
"Base32 Hex Alphabet" equivalents as specified in Table 4 of RFC 4648.
|
private byte[] |
lineSeparator
Line separator for encoding.
|
private static long |
MASK_1BITS
Mask used to extract 1 bits, used when decoding final trailing character.
|
private static long |
MASK_2BITS
Mask used to extract 2 bits, used when decoding final trailing character.
|
private static long |
MASK_3BITS
Mask used to extract 3 bits, used when decoding final trailing character.
|
private static long |
MASK_4BITS
Mask used to extract 4 bits, used when decoding final trailing character.
|
private static int |
MASK_5BITS
Mask used to extract 5 bits, used when encoding Base32 bytes
|
CHUNK_SEPARATOR, DECODING_POLICY_DEFAULT, EOF, lineLength, MASK_8BITS, MIME_CHUNK_SIZE, pad, PAD, PAD_DEFAULT, PEM_CHUNK_SIZE
Constructor and Description |
---|
Base32()
Creates a Base32 codec used for decoding and encoding.
|
Base32(boolean useHex)
Creates a Base32 codec used for decoding and encoding.
|
Base32(boolean useHex,
byte padding)
Creates a Base32 codec used for decoding and encoding.
|
Base32(byte pad)
Creates a Base32 codec used for decoding and encoding.
|
Base32(int lineLength)
Creates a Base32 codec used for decoding and encoding.
|
Base32(int lineLength,
byte[] lineSeparator)
Creates a Base32 codec used for decoding and encoding.
|
Base32(int lineLength,
byte[] lineSeparator,
boolean useHex)
Creates a Base32 / Base32 Hex codec used for decoding and encoding.
|
Base32(int lineLength,
byte[] lineSeparator,
boolean useHex,
byte padding)
Creates a Base32 / Base32 Hex codec used for decoding and encoding.
|
Base32(int lineLength,
byte[] lineSeparator,
boolean useHex,
byte padding,
CodecPolicy decodingPolicy)
Creates a Base32 / Base32 Hex codec used for decoding and encoding.
|
Modifier and Type | Method and Description |
---|---|
(package private) void |
decode(byte[] input,
int inPos,
int inAvail,
BaseNCodec.Context context)
Decodes all of the provided data, starting at inPos, for inAvail bytes.
|
(package private) void |
encode(byte[] input,
int inPos,
int inAvail,
BaseNCodec.Context context)
Encodes all of the provided data, starting at inPos, for inAvail bytes.
|
boolean |
isInAlphabet(byte octet)
Returns whether or not the
octet is in the Base32 alphabet. |
private void |
validateCharacter(long emptyBitsMask,
BaseNCodec.Context context)
Validates whether decoding the final trailing character is possible in the context
of the set of possible base 32 values.
|
private void |
validateTrailingCharacters()
Validates whether decoding allows final trailing characters that cannot be
created during encoding.
|
available, containsAlphabetOrPad, decode, decode, decode, encode, encode, encode, encodeAsString, encodeToString, ensureBufferSize, getChunkSeparator, getCodecPolicy, getDefaultBufferSize, getEncodedLength, hasData, isInAlphabet, isInAlphabet, isStrictDecoding, isWhiteSpace, readResults
private static final int BITS_PER_ENCODED_BYTE
private static final int BYTES_PER_ENCODED_BLOCK
private static final int BYTES_PER_UNENCODED_BLOCK
private static final byte[] DECODE_TABLE
private static final byte[] ENCODE_TABLE
private static final byte[] HEX_DECODE_TABLE
private static final byte[] HEX_ENCODE_TABLE
private static final int MASK_5BITS
private static final long MASK_4BITS
private static final long MASK_3BITS
private static final long MASK_2BITS
private static final long MASK_1BITS
private final int decodeSize
decodeSize = {@link #BYTES_PER_ENCODED_BLOCK} - 1 + lineSeparator.length;
private final byte[] decodeTable
private final int encodeSize
encodeSize = {@link #BYTES_PER_ENCODED_BLOCK} + lineSeparator.length;
private final byte[] encodeTable
private final byte[] lineSeparator
public Base32()
When encoding the line length is 0 (no chunking).
public Base32(boolean useHex)
When encoding the line length is 0 (no chunking).
useHex
- if true
then use Base32 Hex alphabetpublic Base32(boolean useHex, byte padding)
When encoding the line length is 0 (no chunking).
useHex
- if true
then use Base32 Hex alphabetpadding
- byte used as padding byte.public Base32(byte pad)
When encoding the line length is 0 (no chunking).
pad
- byte used as padding byte.public Base32(int lineLength)
When encoding the line length is given in the constructor, the line separator is CRLF.
lineLength
- Each line of encoded data will be at most of the given length (rounded down to nearest multiple of
8). If lineLength <= 0, then the output will not be divided into lines (chunks). Ignored when
decoding.public Base32(int lineLength, byte[] lineSeparator)
When encoding the line length and line separator are given in the constructor.
Line lengths that aren't multiples of 8 will still essentially end up being multiples of 8 in the encoded data.
lineLength
- Each line of encoded data will be at most of the given length (rounded down to nearest multiple of
8). If lineLength <= 0, then the output will not be divided into lines (chunks). Ignored when
decoding.lineSeparator
- Each line of encoded data will end with this sequence of bytes.java.lang.IllegalArgumentException
- Thrown when the lineSeparator
contains Base32 characters.public Base32(int lineLength, byte[] lineSeparator, boolean useHex)
When encoding the line length and line separator are given in the constructor.
Line lengths that aren't multiples of 8 will still essentially end up being multiples of 8 in the encoded data.
lineLength
- Each line of encoded data will be at most of the given length (rounded down to nearest multiple of
8). If lineLength <= 0, then the output will not be divided into lines (chunks). Ignored when
decoding.lineSeparator
- Each line of encoded data will end with this sequence of bytes.useHex
- if true
, then use Base32 Hex alphabet, otherwise use Base32 alphabetjava.lang.IllegalArgumentException
- Thrown when the lineSeparator
contains Base32 characters. Or the
lineLength > 0 and lineSeparator is null.public Base32(int lineLength, byte[] lineSeparator, boolean useHex, byte padding)
When encoding the line length and line separator are given in the constructor.
Line lengths that aren't multiples of 8 will still essentially end up being multiples of 8 in the encoded data.
lineLength
- Each line of encoded data will be at most of the given length (rounded down to nearest multiple of
8). If lineLength <= 0, then the output will not be divided into lines (chunks). Ignored when
decoding.lineSeparator
- Each line of encoded data will end with this sequence of bytes.useHex
- if true
, then use Base32 Hex alphabet, otherwise use Base32 alphabetpadding
- byte used as padding byte.java.lang.IllegalArgumentException
- Thrown when the lineSeparator
contains Base32 characters. Or the
lineLength > 0 and lineSeparator is null.public Base32(int lineLength, byte[] lineSeparator, boolean useHex, byte padding, CodecPolicy decodingPolicy)
When encoding the line length and line separator are given in the constructor.
Line lengths that aren't multiples of 8 will still essentially end up being multiples of 8 in the encoded data.
lineLength
- Each line of encoded data will be at most of the given length (rounded down to nearest multiple of
8). If lineLength <= 0, then the output will not be divided into lines (chunks). Ignored when
decoding.lineSeparator
- Each line of encoded data will end with this sequence of bytes.useHex
- if true
, then use Base32 Hex alphabet, otherwise use Base32 alphabetpadding
- byte used as padding byte.decodingPolicy
- The decoding policy.java.lang.IllegalArgumentException
- Thrown when the lineSeparator
contains Base32 characters. Or the
lineLength > 0 and lineSeparator is null.void decode(byte[] input, int inPos, int inAvail, BaseNCodec.Context context)
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-Base32 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.
Output is written to Context#buffer
as 8-bit
octets, using Context#pos
as the buffer position
decode
in class BaseNCodec
input
- byte[] array of ascii data to Base32 decode.inPos
- Position to start reading data from.inAvail
- Amount of bytes available from input for decoding.context
- the context to be usedvoid encode(byte[] input, int inPos, int inAvail, BaseNCodec.Context context)
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, so flush last remaining bytes (if not multiple of 5).
encode
in class BaseNCodec
input
- byte[] array of binary data to Base32 encode.inPos
- Position to start reading data from.inAvail
- Amount of bytes available from input for encoding.context
- the context to be usedpublic boolean isInAlphabet(byte octet)
octet
is in the Base32 alphabet.isInAlphabet
in class BaseNCodec
octet
- The value to testtrue
if the value is defined in the the Base32 alphabet false
otherwise.private void validateCharacter(long emptyBitsMask, BaseNCodec.Context context)
The character is valid if the lower bits within the provided mask are zero. This is used to test the final trailing base-32 digit is zero in the bits that will be discarded.
emptyBitsMask
- The mask of the lower bits that should be emptycontext
- the context to be usedjava.lang.IllegalArgumentException
- if the bits being checked contain any non-zero valueprivate void validateTrailingCharacters()
java.lang.IllegalArgumentException
- if strict decoding is enabled