Package org.bouncycastle.crypto.digests

Class Blake2sDigest

  • All Implemented Interfaces:
    Digest, ExtendedDigest
    public class Blake2sDigest
extends java.lang.Object
implements ExtendedDigest
    Implementation of the cryptographic hash function BLAKE2s.

    BLAKE2s offers a built-in keying mechanism to be used directly for authentication ("Prefix-MAC") rather than a HMAC construction.

    BLAKE2s offers a built-in support for a salt for randomized hashing and a personal string for defining a unique hash function for each application.

    BLAKE2s is optimized for 32-bit platforms and produces digests of any size between 1 and 32 bytes.

    • Constructor Summary

      Constructors 
      Constructor Description
      Blake2sDigest()
      BLAKE2s-256 for hashing.
      Blake2sDigest​(byte[] key)
      BLAKE2s for authentication ("Prefix-MAC mode").
      Blake2sDigest​(byte[] key, int digestBytes, byte[] salt, byte[] personalization)
      BLAKE2s with key, required digest length, salt and personalization.
      Blake2sDigest​(int digestBits)
      BLAKE2s for hashing.
      Blake2sDigest​(Blake2sDigest digest)  

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void clearKey()
      Overwrite the key if it is no longer used (zeroization).
      void clearSalt()
      Overwrite the salt (pepper) if it is secret and no longer used (zeroization).
      int doFinal​(byte[] out, int outOffset)
      Close the digest, producing the final digest value.
      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.
      void reset()
      Reset the digest back to its initial state.
      void update​(byte b)
      Update the message digest with a single byte.
      void update​(byte[] message, int offset, 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

    • Constructor Detail

      • Blake2sDigest

        public Blake2sDigest()
        BLAKE2s-256 for hashing.

      • Blake2sDigest

        public Blake2sDigest​(int digestBits)
        BLAKE2s for hashing.
        Parameters:
        digestBits - the desired digest length in bits. Must be a multiple of 8 and less than 256.

      • Blake2sDigest

        public Blake2sDigest​(byte[] key)
        BLAKE2s for authentication ("Prefix-MAC mode").

        After calling the doFinal() method, the key will remain to be used for further computations of this instance. The key can be overwritten using the clearKey() method.

        Parameters:
        key - a key up to 32 bytes or null

      • Blake2sDigest

        public Blake2sDigest​(byte[] key,
                     int digestBytes,
                     byte[] salt,
                     byte[] personalization)
        BLAKE2s with key, required digest length, salt and personalization.

        After calling the doFinal() method, the key, the salt and the personal string will remain and might be used for further computations with this instance. The key can be overwritten using the clearKey() method, the salt (pepper) can be overwritten using the clearSalt() method.

        Parameters:
        key - a key up to 32 bytes or null
        digestBytes - from 1 up to 32 bytes
        salt - 8 bytes or null
        personalization - 8 bytes or null

    • Method Detail

      • update

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

      • update

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

      • 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.

      • 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

      • 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.

      • clearKey

        public void clearKey()
        Overwrite the key if it is no longer used (zeroization).

      • clearSalt

        public void clearSalt()
        Overwrite the salt (pepper) if it is secret and no longer used (zeroization).