Package org.bouncycastle.crypto.digests

Class Blake2xsDigest

java.lang.Object
org.bouncycastle.crypto.digests.Blake2xsDigest
All Implemented Interfaces:
Digest, ExtendedDigest, Xof
public class Blake2xsDigest extends 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 final 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)
     
    Blake2xsDigest(int digestBytes, byte[] key)
    BLAKE2xs with key
    Blake2xsDigest(int digestBytes, byte[] key, byte[] salt, byte[] personalization, CryptoServicePurpose purpose)
    BLAKE2xs with key, salt and personalization
    Blake2xsDigest(int digestBytes, CryptoServicePurpose purpose)
    BLAKE2xs for hashing
    Blake2xsDigest(Blake2xsDigest digest)
     

  • Method Summary

    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.
    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 Details

    • UNKNOWN_DIGEST_LENGTH

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

  • Constructor Details

    • Blake2xsDigest

      public Blake2xsDigest()
      BLAKE2xs for hashing with unknown digest length

    • Blake2xsDigest

      public Blake2xsDigest(int digestBytes, CryptoServicePurpose purpose)
      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)

    • 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, CryptoServicePurpose purpose)
      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

    • Blake2xsDigest

      public Blake2xsDigest(Blake2xsDigest digest)

  • Method Details

    • getAlgorithmName

      public 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