Package org.bouncycastle.crypto.digests

Class Blake2xsDigest

  • All Implemented Interfaces:
    Digest, ExtendedDigest, Xof
    public class Blake2xsDigest
extends java.lang.Object
implements Xof
    Implementation of the eXtendable Output Function (XOF) BLAKE2xs.

    BLAKE2xs offers a built-in keying mechanism to be used directly for authentication ("Prefix-MAC") rather than a HMAC construction.

    BLAKE2xs offers a built-in support for a salt for randomized hashing and a personal string for defining a unique hash function for each application.

    BLAKE2xs is optimized for 32-bit platforms and produces digests of any size between 1 and 2^16-2 bytes. The length can also be unknown and then the maximum length will be 2^32 blocks of 32 bytes.

    • Field Summary

      Fields 
      Modifier and Type Field Description
      static int UNKNOWN_DIGEST_LENGTH
      Magic number to indicate an unknown length of digest

    • Constructor Summary

      Constructors 
      Constructor Description
      Blake2xsDigest()
      BLAKE2xs for hashing with unknown digest length
      Blake2xsDigest​(int digestBytes)
      BLAKE2xs for hashing
      Blake2xsDigest​(int digestBytes, byte[] key)
      BLAKE2xs with key
      Blake2xsDigest​(int digestBytes, byte[] key, byte[] salt, byte[] personalization)
      BLAKE2xs with key, salt and personalization
      Blake2xsDigest​(Blake2xsDigest digest)  

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      int doFinal​(byte[] out, int outOffset)
      Close the digest, producing the final digest value.
      int doFinal​(byte[] out, int outOff, int outLen)
      Close the digest, producing the final digest value.
      int doOutput​(byte[] out, int outOff, int outLen)
      Start outputting the results of the final calculation for this digest.
      java.lang.String getAlgorithmName()
      Return the algorithm name.
      int getByteLength()
      Return the size in bytes of the internal buffer the digest applies its compression function to.
      int getDigestSize()
      Return the size in bytes of the digest produced by this message digest.
      long getUnknownMaxLength()
      Return the maximum size in bytes the digest can produce when the length is unknown
      void reset()
      Reset the digest back to its initial state.
      void update​(byte in)
      Update the message digest with a single byte.
      void update​(byte[] in, int inOff, int len)
      Update the message digest with a block of bytes.

      • Methods inherited from class java.lang.Object

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

    • Field Detail

      • UNKNOWN_DIGEST_LENGTH

        public static final int UNKNOWN_DIGEST_LENGTH
        Magic number to indicate an unknown length of digest
        See Also:
        Constant Field Values

    • Constructor Detail

      • Blake2xsDigest

        public Blake2xsDigest()
        BLAKE2xs for hashing with unknown digest length

      • Blake2xsDigest

        public Blake2xsDigest​(int digestBytes)
        BLAKE2xs for hashing
        Parameters:
        digestBytes - The desired digest length in bytes. Must be above 1 and less than 2^16-1

      • Blake2xsDigest

        public Blake2xsDigest​(int digestBytes,
                      byte[] key)
        BLAKE2xs with key
        Parameters:
        digestBytes - The desired digest length in bytes. Must be above 1 and less than 2^16-1
        key - A key up to 32 bytes or null

      • Blake2xsDigest

        public Blake2xsDigest​(int digestBytes,
                      byte[] key,
                      byte[] salt,
                      byte[] personalization)
        BLAKE2xs with key, salt and personalization
        Parameters:
        digestBytes - The desired digest length in bytes. Must be above 1 and less than 2^16-1
        key - A key up to 32 bytes or null
        salt - 8 bytes or null
        personalization - 8 bytes or null

    • Method Detail

      • getAlgorithmName

        public java.lang.String getAlgorithmName()
        Return the algorithm name.
        Specified by:
        getAlgorithmName in interface Digest
        Returns:
        the algorithm name

      • getDigestSize

        public int getDigestSize()
        Return the size in bytes of the digest produced by this message digest.
        Specified by:
        getDigestSize in interface Digest
        Returns:
        the size in bytes of the digest produced by this message digest.

      • getByteLength

        public int getByteLength()
        Return the size in bytes of the internal buffer the digest applies its compression function to.
        Specified by:
        getByteLength in interface ExtendedDigest
        Returns:
        byte length of the digest's internal buffer.

      • getUnknownMaxLength

        public long getUnknownMaxLength()
        Return the maximum size in bytes the digest can produce when the length is unknown
        Returns:
        byte length of the largest digest with unknown length

      • update

        public void update​(byte in)
        Update the message digest with a single byte.
        Specified by:
        update in interface Digest
        Parameters:
        in - the input byte to be entered.

      • update

        public void update​(byte[] in,
                   int inOff,
                   int len)
        Update the message digest with a block of bytes.
        Specified by:
        update in interface Digest
        Parameters:
        in - the byte array containing the data.
        inOff - the offset into the byte array where the data starts.
        len - the length of the data.

      • reset

        public void reset()
        Reset the digest back to its initial state. The key, the salt and the personal string will remain for further computations.
        Specified by:
        reset in interface Digest

      • doFinal

        public int doFinal​(byte[] out,
                   int outOffset)
        Close the digest, producing the final digest value. The doFinal() call leaves the digest reset. Key, salt and personal string remain.
        Specified by:
        doFinal in interface Digest
        Parameters:
        out - the array the digest is to be copied into.
        outOffset - the offset into the out array the digest is to start at.

      • doFinal

        public int doFinal​(byte[] out,
                   int outOff,
                   int outLen)
        Close the digest, producing the final digest value. The doFinal() call leaves the digest reset. Key, salt, personal string remain.
        Specified by:
        doFinal in interface Xof
        Parameters:
        out - output array to write the output bytes to.
        outOff - offset to start writing the bytes at.
        outLen - the number of output bytes requested.
        Returns:
        the number of bytes written

      • doOutput

        public int doOutput​(byte[] out,
                    int outOff,
                    int outLen)
        Start outputting the results of the final calculation for this digest. Unlike doFinal, this method will continue producing output until the Xof is explicitly reset, or signals otherwise.
        Specified by:
        doOutput in interface Xof
        Parameters:
        out - output array to write the output bytes to.
        outOff - offset to start writing the bytes at.
        outLen - the number of output bytes requested.
        Returns:
        the number of bytes written