Package com.jsql.util.bruter

Class BaseNCodec

java.lang.Object
com.jsql.util.bruter.BaseNCodec
All Implemented Interfaces:
org.apache.commons.codec.BinaryDecoder, org.apache.commons.codec.BinaryEncoder, org.apache.commons.codec.Decoder, org.apache.commons.codec.Encoder
Direct Known Subclasses:
Base16
public abstract class BaseNCodec extends Object implements org.apache.commons.codec.BinaryEncoder, org.apache.commons.codec.BinaryDecoder
Abstract superclass for Base-N encoders and decoders.

This class is thread-safe.

You can set the decoding behavior when the input bytes contain leftover trailing bits that cannot be created by a valid encoding. These can be bits that are unused from the final character or entire characters. The default mode is lenient decoding.
  • Lenient: Any trailing bits are composed into 8-bit bytes where possible. The remainder are discarded.
  • Strict: The decoding will raise an IllegalArgumentException if trailing bits are not part of a valid encoding. Any unused bits from the final character must be zero. Impossible counts of entire final characters are not allowed.

When strict decoding is enabled it is expected that the decoded bytes will be re-encoded to a byte array that matches the original, i.e. no changes occur on the final character. This requires that the input bytes use the same padding and alphabet as the encoder.

  • Nested Class Summary

    Nested Classes
    Modifier and Type
    Class
    Description
    protected static class 
    BaseNCodec.Context
    Holds thread context so classes can be thread-safe.

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    protected static final CodecPolicy
    DECODING_POLICY_DEFAULT
    The default decoding policy.
    protected final int
    lineLength
    Chunksize for encoding.
    protected static final int
    MASK_8BITS
    Mask used to extract 8 bits, used in decoding bytes
    static final int
    MIME_CHUNK_SIZE
    MIME chunk size per RFC 2045 section 6.8.
    protected final byte
    pad
     
    protected static final byte
    PAD_DEFAULT
    Byte used to pad output.
    static final int
    PEM_CHUNK_SIZE
    PEM chunk size per RFC 1421 section 4.3.2.4.

  • Constructor Summary

    Constructors
    Modifier
    Constructor
    Description
    protected
    BaseNCodec(int unencodedBlockSize, int encodedBlockSize, int lineLength, int chunkSeparatorLength)
    Note lineLength is rounded down to the nearest multiple of the encoded block size.
    protected
    BaseNCodec(int unencodedBlockSize, int encodedBlockSize, int lineLength, int chunkSeparatorLength, byte pad)
    Note lineLength is rounded down to the nearest multiple of the encoded block size.
    protected
    BaseNCodec(int unencodedBlockSize, int encodedBlockSize, int lineLength, int chunkSeparatorLength, byte pad, CodecPolicy decodingPolicy)
    Note lineLength is rounded down to the nearest multiple of the encoded block size.

  • Method Summary

    Modifier and Type
    Method
    Description
    protected boolean
    containsAlphabetOrPad(byte[] arrayOctet)
    Tests a given byte array to see if it contains any characters within the alphabet or PAD.
    byte[]
    decode(byte[] pArray)
    Decodes a byte[] containing characters in the Base-N alphabet.
    abstract void
    decode(byte[] pArray, int i, int length, BaseNCodec.Context context)
     
    Object
    decode(Object obj)
    Decodes an Object using the Base-N algorithm.
    byte[]
    decode(String pArray)
    Decodes a String containing characters in the Base-N alphabet.
    byte[]
    encode(byte[] pArray)
    Encodes a byte[] containing binary data, into a byte[] containing characters in the alphabet.
    byte[]
    encode(byte[] pArray, int offset, int length)
    Encodes a byte[] containing binary data, into a byte[] containing characters in the alphabet.
    abstract void
    encode(byte[] pArray, int i, int length, BaseNCodec.Context context)
     
    Object
    encode(Object obj)
    Encodes an Object using the Base-N algorithm.
    String
    encodeAsString(byte[] pArray)
    Encodes a byte[] containing binary data, into a String containing characters in the appropriate alphabet.
    String
    encodeToString(byte[] pArray)
    Encodes a byte[] containing binary data, into a String containing characters in the Base-N alphabet.
    protected byte[]
    ensureBufferSize(int size, BaseNCodec.Context context)
    Ensure that the buffer has room for size bytes
    static byte[]
    getChunkSeparator()
    Gets a copy of the chunk separator per RFC 2045 section 2.1.
    CodecPolicy
    getCodecPolicy()
    Returns the decoding behavior policy.
    protected int
    getDefaultBufferSize()
    Get the default buffer size.
    long
    getEncodedLength(byte[] pArray)
    Calculates the amount of space needed to encode the supplied array.
    boolean
    hasData(BaseNCodec.Context context)
    Returns true if this object has buffered data for reading.
    protected abstract boolean
    isInAlphabet(byte value)
    Returns whether or not the octet is in the current alphabet.
    boolean
    isInAlphabet(byte[] arrayOctet, boolean allowWSPad)
    Tests a given byte array to see if it contains only valid characters within the alphabet.
    boolean
    isInAlphabet(String basen)
    Tests a given String to see if it contains only valid characters within the alphabet.
    boolean
    isStrictDecoding()
    Returns true if decoding behavior is strict.
    protected static boolean
    isWhiteSpace(byte byteToCheck)
    Checks if a byte value is whitespace or not.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Field Details

    • MIME_CHUNK_SIZE

      public static final int MIME_CHUNK_SIZE
      MIME chunk size per RFC 2045 section 6.8.

      The 76 character limit does not count the trailing CRLF, but counts all other characters, including any equal signs.

      See Also:

    • PEM_CHUNK_SIZE

      public static final int PEM_CHUNK_SIZE
      PEM chunk size per RFC 1421 section 4.3.2.4.

      The 64 character limit does not count the trailing CRLF, but counts all other characters, including any equal signs.

      See Also:

    • MASK_8BITS

      protected static final int MASK_8BITS
      Mask used to extract 8 bits, used in decoding bytes
      See Also:

    • PAD_DEFAULT

      protected static final byte PAD_DEFAULT
      Byte used to pad output.
      See Also:

    • DECODING_POLICY_DEFAULT

      protected static final CodecPolicy DECODING_POLICY_DEFAULT
      The default decoding policy.
      Since:
      1.15

    • pad

      protected final byte pad

    • lineLength

      protected final int lineLength
      Chunksize for encoding. Not used when decoding. A value of zero or less implies no chunking of the encoded data. Rounded down to nearest multiple of encodedBlockSize.

  • Constructor Details

    • BaseNCodec

      protected BaseNCodec(int unencodedBlockSize, int encodedBlockSize, int lineLength, int chunkSeparatorLength)
      Note lineLength is rounded down to the nearest multiple of the encoded block size. If chunkSeparatorLength is zero, then chunking is disabled.
      Parameters:
      unencodedBlockSize - the size of an unencoded block (e.g. Base64 = 3)
      encodedBlockSize - the size of an encoded block (e.g. Base64 = 4)
      lineLength - if > 0, use chunking with a length lineLength
      chunkSeparatorLength - the chunk separator length, if relevant

    • BaseNCodec

      protected BaseNCodec(int unencodedBlockSize, int encodedBlockSize, int lineLength, int chunkSeparatorLength, byte pad)
      Note lineLength is rounded down to the nearest multiple of the encoded block size. If chunkSeparatorLength is zero, then chunking is disabled.
      Parameters:
      unencodedBlockSize - the size of an unencoded block (e.g. Base64 = 3)
      encodedBlockSize - the size of an encoded block (e.g. Base64 = 4)
      lineLength - if > 0, use chunking with a length lineLength
      chunkSeparatorLength - the chunk separator length, if relevant
      pad - byte used as padding byte.

    • BaseNCodec

      protected BaseNCodec(int unencodedBlockSize, int encodedBlockSize, int lineLength, int chunkSeparatorLength, byte pad, CodecPolicy decodingPolicy)
      Note lineLength is rounded down to the nearest multiple of the encoded block size. If chunkSeparatorLength is zero, then chunking is disabled.
      Parameters:
      unencodedBlockSize - the size of an unencoded block (e.g. Base64 = 3)
      encodedBlockSize - the size of an encoded block (e.g. Base64 = 4)
      lineLength - if > 0, use chunking with a length lineLength
      chunkSeparatorLength - the chunk separator length, if relevant
      pad - byte used as padding byte.
      decodingPolicy - Decoding policy.
      Since:
      1.15

  • Method Details

    • getChunkSeparator

      public static byte[] getChunkSeparator()
      Gets a copy of the chunk separator per RFC 2045 section 2.1.
      Returns:
      the chunk separator
      Since:
      1.15
      See Also:

    • isWhiteSpace

      protected static boolean isWhiteSpace(byte byteToCheck)
      Checks if a byte value is whitespace or not. Whitespace is taken to mean: space, tab, CR, LF
      Parameters:
      byteToCheck - the byte to check
      Returns:
      true if byte is whitespace, false otherwise

    • containsAlphabetOrPad

      protected boolean containsAlphabetOrPad(byte[] arrayOctet)
      Tests a given byte array to see if it contains any characters within the alphabet or PAD. Intended for use in checking line-ending arrays
      Parameters:
      arrayOctet - byte array to test
      Returns:
      true if any byte is a valid character in the alphabet or PAD; false otherwise

    • decode

      public byte[] decode(byte[] pArray)
      Decodes a byte[] containing characters in the Base-N alphabet.
      Specified by:
      decode in interface org.apache.commons.codec.BinaryDecoder
      Parameters:
      pArray - A byte array containing Base-N character data
      Returns:
      a byte array containing binary data

    • decode

      public abstract void decode(byte[] pArray, int i, int length, BaseNCodec.Context context)

    • decode

      public Object decode(Object obj) throws org.apache.commons.codec.DecoderException
      Decodes an Object using the Base-N algorithm. This method is provided in order to satisfy the requirements of the Decoder interface, and will throw a DecoderException if the supplied object is not of type byte[] or String.
      Specified by:
      decode in interface org.apache.commons.codec.Decoder
      Parameters:
      obj - Object to decode
      Returns:
      An object (of type byte[]) containing the binary data which corresponds to the byte[] or String supplied.
      Throws:
      org.apache.commons.codec.DecoderException - if the parameter supplied is not of type byte[]

    • decode

      public byte[] decode(String pArray)
      Decodes a String containing characters in the Base-N alphabet.
      Parameters:
      pArray - A String containing Base-N character data
      Returns:
      a byte array containing binary data

    • encode

      public byte[] encode(byte[] pArray)
      Encodes a byte[] containing binary data, into a byte[] containing characters in the alphabet.
      Specified by:
      encode in interface org.apache.commons.codec.BinaryEncoder
      Parameters:
      pArray - a byte array containing binary data
      Returns:
      A byte array containing only the base N alphabetic character data

    • encode

      public byte[] encode(byte[] pArray, int offset, int length)
      Encodes a byte[] containing binary data, into a byte[] containing characters in the alphabet.
      Parameters:
      pArray - a byte array containing binary data
      offset - initial offset of the subarray.
      length - length of the subarray.
      Returns:
      A byte array containing only the base N alphabetic character data
      Since:
      1.11

    • encode

      public abstract void encode(byte[] pArray, int i, int length, BaseNCodec.Context context)

    • encode

      public Object encode(Object obj) throws org.apache.commons.codec.EncoderException
      Encodes an Object using the Base-N algorithm. This method is provided in order to satisfy the requirements of the Encoder interface, and will throw an EncoderException if the supplied object is not of type byte[].
      Specified by:
      encode in interface org.apache.commons.codec.Encoder
      Parameters:
      obj - Object to encode
      Returns:
      An object (of type byte[]) containing the Base-N encoded data which corresponds to the byte[] supplied.
      Throws:
      org.apache.commons.codec.EncoderException - if the parameter supplied is not of type byte[]

    • encodeAsString

      public String encodeAsString(byte[] pArray)
      Encodes a byte[] containing binary data, into a String containing characters in the appropriate alphabet. Uses UTF8 encoding.
      Parameters:
      pArray - a byte array containing binary data
      Returns:
      String containing only character data in the appropriate alphabet.
      Since:
      1.5 This is a duplicate of encodeToString(byte[]); it was merged during refactoring.

    • encodeToString

      public String encodeToString(byte[] pArray)
      Encodes a byte[] containing binary data, into a String containing characters in the Base-N alphabet. Uses UTF8 encoding.
      Parameters:
      pArray - a byte array containing binary data
      Returns:
      A String containing only Base-N character data

    • ensureBufferSize

      protected byte[] ensureBufferSize(int size, BaseNCodec.Context context)
      Ensure that the buffer has room for size bytes
      Parameters:
      size - minimum spare space required
      context - the context to be used
      Returns:
      the buffer

    • getCodecPolicy

      public CodecPolicy getCodecPolicy()
      Returns the decoding behavior policy.

      The default is lenient. If the decoding policy is strict, then decoding will raise an IllegalArgumentException if trailing bits are not part of a valid encoding. Decoding will compose trailing bits into 8-bit bytes and discard the remainder.

      Returns:
      true if using strict decoding
      Since:
      1.15

    • getDefaultBufferSize

      protected int getDefaultBufferSize()
      Get the default buffer size. Can be overridden.
      Returns:
      the default buffer size.

    • getEncodedLength

      public long getEncodedLength(byte[] pArray)
      Calculates the amount of space needed to encode the supplied array.
      Parameters:
      pArray - byte[] array which will later be encoded
      Returns:
      amount of space needed to encoded the supplied array. Returns a long since a max-len array will require > Integer.MAX_VALUE

    • hasData

      public boolean hasData(BaseNCodec.Context context)
      Returns true if this object has buffered data for reading.
      Parameters:
      context - the context to be used
      Returns:
      true if there is data still available for reading.

    • isInAlphabet

      protected abstract boolean isInAlphabet(byte value)
      Returns whether or not the octet is in the current alphabet. Does not allow whitespace or pad.
      Parameters:
      value - The value to test
      Returns:
      true if the value is defined in the current alphabet, false otherwise.

    • isInAlphabet

      public boolean isInAlphabet(byte[] arrayOctet, boolean allowWSPad)
      Tests a given byte array to see if it contains only valid characters within the alphabet. The method optionally treats whitespace and pad as valid.
      Parameters:
      arrayOctet - byte array to test
      allowWSPad - if true, then whitespace and PAD are also allowed
      Returns:
      true if all bytes are valid characters in the alphabet or if the byte array is empty; false, otherwise

    • isInAlphabet

      public boolean isInAlphabet(String basen)
      Tests a given String to see if it contains only valid characters within the alphabet. The method treats whitespace and PAD as valid.
      Parameters:
      basen - String to test
      Returns:
      true if all characters in the String are valid characters in the alphabet or if the String is empty; false, otherwise
      See Also:

    • isStrictDecoding

      public boolean isStrictDecoding()
      Returns true if decoding behavior is strict. Decoding will raise an IllegalArgumentException if trailing bits are not part of a valid encoding.

      The default is false for lenient decoding. Decoding will compose trailing bits into 8-bit bytes and discard the remainder.

      Returns:
      true if using strict decoding
      Since:
      1.15