Package rsb.util

Class Base64

java.lang.Object
rsb.util.Base64
public class Base64 extends Object
Provides Base64 encoding and decoding as defined by RFC 2045. 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:
  • URL-safe mode: Default off.
  • 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.
  • Line separator: Default is CRLF ("\r\n")

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 not thread-safe. Each thread should use its own instance.

Since:
1.0
Author:
Apache Software Foundation
See Also:

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final int
    MIME_CHUNK_SIZE
    MIME chunk size per RFC 2045 section 6.8.
    static final int
    PEM_CHUNK_SIZE
    PEM chunk size per RFC 1421 section 4.3.2.4.

  • Constructor Summary

    Constructors
    Constructor
    Description
    Base64()
    Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode.
    Base64(boolean urlSafe)
    Creates a Base64 codec used for decoding (all modes) and encoding in the given URL-safe mode.
    Base64(int lineLength)
    Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode.
    Base64(int lineLength, byte[] lineSeparator)
    Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode.
    Base64(int lineLength, byte[] lineSeparator, boolean urlSafe)
    Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode.

  • Method Summary

    Modifier and Type
    Method
    Description
    byte[]
    decode(byte[] pArray)
    Decodes a byte[] containing characters in the Base-N alphabet.
    Object
    decode(Object pObject)
    Decodes an Object using the Base-N algorithm.
    byte[]
    decode(String pArray)
    Decodes a String containing characters in the Base-N alphabet.
    static byte[]
    decodeBase64(byte[] base64Data)
    Decodes Base64 data into octets
    static byte[]
    decodeBase64(String base64String)
    Decodes a Base64 String into octets
    static BigInteger
    decodeInteger(byte[] pArray)
    Decodes a byte64-encoded integer according to crypto standards such as W3C's XML-Signature
    byte[]
    encode(byte[] pArray)
    Encodes a byte[] containing binary data, into a byte[] containing characters in the alphabet.
    Object
    encode(Object pObject)
    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.
    static byte[]
    encodeBase64(byte[] binaryData)
    Encodes binary data using the base64 algorithm but does not chunk the output.
    static byte[]
    encodeBase64(byte[] binaryData, boolean isChunked)
    Encodes binary data using the base64 algorithm, optionally chunking the output into 76 character blocks.
    static byte[]
    encodeBase64(byte[] binaryData, boolean isChunked, boolean urlSafe)
    Encodes binary data using the base64 algorithm, optionally chunking the output into 76 character blocks.
    static byte[]
    encodeBase64(byte[] binaryData, boolean isChunked, boolean urlSafe, int maxResultSize)
    Encodes binary data using the base64 algorithm, optionally chunking the output into 76 character blocks.
    static byte[]
    encodeBase64Chunked(byte[] binaryData)
    Encodes binary data using the base64 algorithm and chunks the encoded output into 76 character blocks
    static String
    encodeBase64String(byte[] binaryData)
    Encodes binary data using the base64 algorithm but does not chunk the output.
    static byte[]
    encodeBase64URLSafe(byte[] binaryData)
    Encodes binary data using a URL-safe variation of the base64 algorithm but does not chunk the output.
    static String
    encodeBase64URLSafeString(byte[] binaryData)
    Encodes binary data using a URL-safe variation of the base64 algorithm but does not chunk the output.
    static byte[]
    encodeInteger(BigInteger bigInt)
    Encodes to a byte64-encoded integer according to crypto standards such as W3C's XML-Signature
    String
    encodeToString(byte[] pArray)
    Encodes a byte[] containing binary data, into a String containing characters in the Base-N alphabet.
    long
    getEncodedLength(byte[] pArray)
    Calculates the amount of space needed to encode the supplied array.
    static boolean
    isBase64(byte octet)
    Returns whether the octet is in the base 64 alphabet.
    static boolean
    isBase64(byte[] arrayOctet)
    Tests a given byte array to see if it contains only valid characters within the Base64 alphabet.
    static boolean
    isBase64(String base64)
    Tests a given String to see if it contains only valid characters within the Base64 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
    isUrlSafe()
    Returns our current encode mode.

    Methods inherited from class java.lang.Object

    equals, 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:

  • Constructor Details

    • Base64

      public Base64()
      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.

    • Base64

      public Base64(boolean urlSafe)
      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.

      Parameters:
      urlSafe - if true, URL-safe encoding is used. In most cases this should be set to false.
      Since:
      1.4

    • Base64

      public Base64(int lineLength)
      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.

      Parameters:
      lineLength - Each line of encoded data will be at most of the given length (rounded down to nearest multiple of 4). If lineLength less than or equal to 0, then the output will not be divided into lines (chunks). Ignored when decoding.
      Since:
      1.4

    • Base64

      public Base64(int lineLength, byte[] lineSeparator)
      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.

      Parameters:
      lineLength - Each line of encoded data will be at most of the given length (rounded down to nearest multiple of 4). If lineLength is less than or equal to 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.
      Throws:
      IllegalArgumentException - Thrown when the provided lineSeparator included some base64 characters.
      Since:
      1.4

    • Base64

      public Base64(int lineLength, byte[] lineSeparator, boolean urlSafe)
      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.

      Parameters:
      lineLength - Each line of encoded data will be at most of the given length (rounded down to nearest multiple of 4). If lineLength less than or equal to 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.
      urlSafe - Instead of emitting '+' and '/' we emit '-' and '_' respectively. urlSafe is only applied to encode operations. Decoding seamlessly handles both modes.
      Throws:
      IllegalArgumentException - The provided lineSeparator included some base64 characters. That's not going to work!
      Since:
      1.4

  • Method Details

    • encode

      public Object encode(Object pObject)
      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[].
      Parameters:
      pObject - Object to encode
      Returns:
      An object (of type byte[]) containing the Base-N encoded data which corresponds to the byte[] supplied.
      Throws:
      IllegalArgumentException - if the parameter supplied is not of type byte[]

    • encodeToString

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

    • decode

      public Object decode(Object pObject) throws IllegalArgumentException
      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.
      Parameters:
      pObject - Object to decode
      Returns:
      An object (of type byte[]) containing the binary data which corresponds to the byte[] or String supplied.
      Throws:
      IllegalArgumentException - 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

    • decode

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

    • 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.

    • 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:

    • 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 greater than Integer.MAX_VALUE

    • isUrlSafe

      public boolean isUrlSafe()
      Returns our current encode mode. True if we're URL-SAFE, false otherwise.
      Returns:
      true if we're in URL-SAFE mode, false otherwise.
      Since:
      1.4

    • isBase64

      public static boolean isBase64(byte octet)
      Returns whether the octet is in the base 64 alphabet.
      Parameters:
      octet - The value to test
      Returns:
      true if the value is defined in the the base 64 alphabet, false otherwise.
      Since:
      1.4

    • isBase64

      public static boolean isBase64(String base64)
      Tests a given String to see if it contains only valid characters within the Base64 alphabet. Currently the method treats whitespace as valid.
      Parameters:
      base64 - String to test
      Returns:
      true if all characters in the String are valid characters in the Base64 alphabet or if the String is empty; false, otherwise
      Since:
      1.5

    • isBase64

      public static boolean isBase64(byte[] arrayOctet)
      Tests a given byte array to see if it contains only valid characters within the Base64 alphabet. Currently the method treats whitespace as valid.
      Parameters:
      arrayOctet - byte array to test
      Returns:
      true if all bytes are valid characters in the Base64 alphabet or if the byte array is empty; false, otherwise
      Since:
      1.5

    • encodeBase64

      public static byte[] encodeBase64(byte[] binaryData)
      Encodes binary data using the base64 algorithm but does not chunk the output.
      Parameters:
      binaryData - binary data to encode
      Returns:
      byte[] containing Base64 characters in their UTF-8 representation.

    • encodeBase64String

      public static String encodeBase64String(byte[] binaryData)
      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).
      Parameters:
      binaryData - binary data to encode
      Returns:
      String containing Base64 characters.
      Since:
      1.4 (NOTE: 1.4 chunked the output, whereas 1.5 does not).

    • encodeBase64URLSafe

      public static byte[] encodeBase64URLSafe(byte[] binaryData)
      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.
      Parameters:
      binaryData - binary data to encode
      Returns:
      byte[] containing Base64 characters in their UTF-8 representation.
      Since:
      1.4

    • encodeBase64URLSafeString

      public static String encodeBase64URLSafeString(byte[] binaryData)
      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.
      Parameters:
      binaryData - binary data to encode
      Returns:
      String containing Base64 characters
      Since:
      1.4

    • encodeBase64Chunked

      public static byte[] encodeBase64Chunked(byte[] binaryData)
      Encodes binary data using the base64 algorithm and chunks the encoded output into 76 character blocks
      Parameters:
      binaryData - binary data to encode
      Returns:
      Base64 characters chunked in 76 character blocks

    • encodeBase64

      public static byte[] encodeBase64(byte[] binaryData, boolean isChunked)
      Encodes binary data using the base64 algorithm, optionally chunking the output into 76 character blocks.
      Parameters:
      binaryData - Array containing binary data to encode.
      isChunked - if true this encoder will chunk the base64 output into 76 character blocks
      Returns:
      Base64-encoded data.
      Throws:
      IllegalArgumentException - Thrown when the input array needs an output array bigger than Integer.MAX_VALUE

    • encodeBase64

      public static byte[] encodeBase64(byte[] binaryData, boolean isChunked, boolean urlSafe)
      Encodes binary data using the base64 algorithm, optionally chunking the output into 76 character blocks.
      Parameters:
      binaryData - Array containing binary data to encode.
      isChunked - if true this encoder will chunk the base64 output into 76 character blocks
      urlSafe - if true this encoder will emit - and _ instead of the usual + and / characters.
      Returns:
      Base64-encoded data.
      Throws:
      IllegalArgumentException - Thrown when the input array needs an output array bigger than Integer.MAX_VALUE
      Since:
      1.4

    • encodeBase64

      public static byte[] encodeBase64(byte[] binaryData, boolean isChunked, boolean urlSafe, int maxResultSize)
      Encodes binary data using the base64 algorithm, optionally chunking the output into 76 character blocks.
      Parameters:
      binaryData - Array containing binary data to encode.
      isChunked - if true this encoder will chunk the base64 output into 76 character blocks
      urlSafe - if true this encoder will emit - and _ instead of the usual + and / characters.
      maxResultSize - The maximum result size to accept.
      Returns:
      Base64-encoded data.
      Throws:
      IllegalArgumentException - Thrown when the input array needs an output array bigger than maxResultSize
      Since:
      1.4

    • decodeBase64

      public static byte[] decodeBase64(String base64String)
      Decodes a Base64 String into octets
      Parameters:
      base64String - String containing Base64 data
      Returns:
      Array containing decoded data.
      Since:
      1.4

    • decodeBase64

      public static byte[] decodeBase64(byte[] base64Data)
      Decodes Base64 data into octets
      Parameters:
      base64Data - Byte array containing Base64 data
      Returns:
      Array containing decoded data.

    • decodeInteger

      public static BigInteger decodeInteger(byte[] pArray)
      Decodes a byte64-encoded integer according to crypto standards such as W3C's XML-Signature
      Parameters:
      pArray - a byte array containing base64 character data
      Returns:
      A BigInteger
      Since:
      1.4

    • encodeInteger

      public static byte[] encodeInteger(BigInteger bigInt)
      Encodes to a byte64-encoded integer according to crypto standards such as W3C's XML-Signature
      Parameters:
      bigInt - a BigInteger
      Returns:
      A byte array containing base64 character data
      Throws:
      NullPointerException - if null is passed in
      Since:
      1.4