Package net.i2p.crypto.eddsa

Class EdDSAEngine

  • Direct Known Subclasses:
    RedDSAEngine
    public class EdDSAEngine
extends Signature
    Signing and verification for EdDSA.

    The EdDSA sign and verify algorithms do not interact well with the Java Signature API, as one or more update() methods must be called before sign() or verify(). Using the standard API, this implementation must copy and buffer all data passed in via update().

    This implementation offers two ways to avoid this copying, but only if all data to be signed or verified is available in a single byte array.

    Option 1:

    1. Call initSign() or initVerify() as usual.
    2. Call setParameter(ONE_SHOT_MODE)
    3. Call update(byte[]) or update(byte[], int, int) exactly once
    4. Call sign() or verify() as usual.
    5. If doing additional one-shot signs or verifies with this object, you must call setParameter(ONE_SHOT_MODE) each time

    Option 2:

    1. Call initSign() or initVerify() as usual.
    2. Call one of the signOneShot() or verifyOneShot() methods.
    3. If doing additional one-shot signs or verifies with this object, just call signOneShot() or verifyOneShot() again.
    Since:
    0.9.15
    Author:
    str4d

    • Field Detail

      • ONE_SHOT_MODE

        public static final AlgorithmParameterSpec ONE_SHOT_MODE
        To efficiently sign or verify data in one shot, pass this to setParameters() after initSign() or initVerify() but BEFORE THE FIRST AND ONLY update(data) or update(data, off, len). The data reference will be saved and then used in sign() or verify() without copying the data. Violate these rules and you will get a SignatureException.
        Since:
        0.9.25

    • Constructor Detail

      • EdDSAEngine

        public EdDSAEngine()
        No specific EdDSA-internal hash requested, allows any EdDSA key.

      • EdDSAEngine

        public EdDSAEngine​(MessageDigest digest)
        Specific EdDSA-internal hash requested, only matching keys will be allowed.
        Parameters:
        digest - the hash algorithm that keys must have to sign or verify.

    • Method Detail

      • digestInitSign

        protected void digestInitSign​(EdDSAPrivateKey privKey)

      • signOneShot

        public byte[] signOneShot​(byte[] data)
                   throws SignatureException
        To efficiently sign all the data in one shot, if it is available, use this method, which will avoid copying the data. Same as: 
          setParameter(ONE_SHOT_MODE)
  update(data)
  sig = sign()
        Parameters:
        data - the message to be signed
        Returns:
        the signature
        Throws:
        SignatureException - if update() already called
        Since:
        0.9.25
        See Also:
        ONE_SHOT_MODE

      • signOneShot

        public byte[] signOneShot​(byte[] data,
                          int off,
                          int len)
                   throws SignatureException
        To efficiently sign all the data in one shot, if it is available, use this method, which will avoid copying the data. Same as: 
          setParameter(ONE_SHOT_MODE)
  update(data, off, len)
  sig = sign()
        Parameters:
        data - byte array containing the message to be signed
        off - the start of the message inside data
        len - the length of the message
        Returns:
        the signature
        Throws:
        SignatureException - if update() already called
        Since:
        0.9.25
        See Also:
        ONE_SHOT_MODE

      • verifyOneShot

        public boolean verifyOneShot​(byte[] data,
                             byte[] signature)
                      throws SignatureException
        To efficiently verify all the data in one shot, if it is available, use this method, which will avoid copying the data. Same as: 
          setParameter(ONE_SHOT_MODE)
  update(data)
  ok = verify(signature)
        Parameters:
        data - the message that was signed
        signature - of the message
        Returns:
        true if the signature is valid, false otherwise
        Throws:
        SignatureException - if update() already called
        Since:
        0.9.25
        See Also:
        ONE_SHOT_MODE

      • verifyOneShot

        public boolean verifyOneShot​(byte[] data,
                             int off,
                             int len,
                             byte[] signature)
                      throws SignatureException
        To efficiently verify all the data in one shot, if it is available, use this method, which will avoid copying the data. Same as: 
          setParameter(ONE_SHOT_MODE)
  update(data, off, len)
  ok = verify(signature)
        Parameters:
        data - byte array containing the message that was signed
        off - the start of the message inside data
        len - the length of the message
        signature - of the message
        Returns:
        true if the signature is valid, false otherwise
        Throws:
        SignatureException - if update() already called
        Since:
        0.9.25
        See Also:
        ONE_SHOT_MODE

      • verifyOneShot

        public boolean verifyOneShot​(byte[] data,
                             byte[] signature,
                             int sigoff,
                             int siglen)
                      throws SignatureException
        To efficiently verify all the data in one shot, if it is available, use this method, which will avoid copying the data. Same as: 
          setParameter(ONE_SHOT_MODE)
  update(data)
  ok = verify(signature, sigoff, siglen)
        Parameters:
        data - the message that was signed
        signature - byte array containing the signature
        sigoff - the start of the signature
        siglen - the length of the signature
        Returns:
        true if the signature is valid, false otherwise
        Throws:
        SignatureException - if update() already called
        Since:
        0.9.25
        See Also:
        ONE_SHOT_MODE

      • verifyOneShot

        public boolean verifyOneShot​(byte[] data,
                             int off,
                             int len,
                             byte[] signature,
                             int sigoff,
                             int siglen)
                      throws SignatureException
        To efficiently verify all the data in one shot, if it is available, use this method, which will avoid copying the data. Same as: 
          setParameter(ONE_SHOT_MODE)
  update(data, off, len)
  ok = verify(signature, sigoff, siglen)
        Parameters:
        data - byte array containing the message that was signed
        off - the start of the message inside data
        len - the length of the message
        signature - byte array containing the signature
        sigoff - the start of the signature
        siglen - the length of the signature
        Returns:
        true if the signature is valid, false otherwise
        Throws:
        SignatureException - if update() already called
        Since:
        0.9.25
        See Also:
        ONE_SHOT_MODE