PSSSigner (Bouncy Castle Library 1.52 API Specification)
Date: 2015-03-01

org.bouncycastle.crypto.signers

## Class PSSSigner

- java.lang.Object
- - org.bouncycastle.crypto.signers.PSSSigner

- All Implemented Interfaces:
    Signer

      public class PSSSigner
      extends java.lang.Object
      implements Signer

  RSA-PSS as described in PKCS# 1 v 2.1.

  Note: the usual value for the salt length is the number of bytes in the hash function.

- - ### Field Summary

    Fields
    Modifier and Type | Field and Description
    --- | ---
    `static byte` | `TRAILER_IMPLICIT`

  - ### Constructor Summary

    Constructors
    Constructor and Description
    `PSSSigner(AsymmetricBlockCipher cipher, Digest contentDigest, Digest mgfDigest, int sLen)`
    `PSSSigner(AsymmetricBlockCipher cipher, Digest contentDigest, Digest mgfDigest, int sLen, byte trailer)`
    `PSSSigner(AsymmetricBlockCipher cipher, Digest digest, int sLen)` basic constructor
    `PSSSigner(AsymmetricBlockCipher cipher, Digest digest, int sLen, byte trailer)`

  - ### Method Summary

    Methods
    Modifier and Type | Method and Description
    --- | ---
    `byte[]` | `generateSignature()` generate a signature for the message we've been loaded with using the key we were initialised with.
    `void` | `init(boolean forSigning, CipherParameters param)` Initialise the signer for signing or verification.
    `void` | `reset()` reset the internal state
    `void` | `update(byte b)` update the internal digest with the byte b
    `void` | `update(byte[] in, int off, int len)` update the internal digest with the byte array in
    `boolean` | `verifySignature(byte[] signature)` return true if the internal state represents the signature described in the passed in array.

    - ### Methods inherited from class java.lang.Object

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

- - ### Field Detail

    - #### TRAILER_IMPLICIT

          public static final byte TRAILER_IMPLICIT

      See Also:
        Constant Field Values

  - ### Constructor Detail

    - #### PSSSigner

          public PSSSigner(AsymmetricBlockCipher cipher,
                   Digest digest,
                   int sLen)

      basic constructor
      Parameters:
        `cipher` - the asymmetric cipher to use.
        `digest` - the digest to use.
        `sLen` - the length of the salt to use (in bytes).

    - #### PSSSigner

          public PSSSigner(AsymmetricBlockCipher cipher,
                   Digest contentDigest,
                   Digest mgfDigest,
                   int sLen)

    - #### PSSSigner

          public PSSSigner(AsymmetricBlockCipher cipher,
                   Digest digest,
                   int sLen,
                   byte trailer)

    - #### PSSSigner

          public PSSSigner(AsymmetricBlockCipher cipher,
                   Digest contentDigest,
                   Digest mgfDigest,
                   int sLen,
                   byte trailer)

  - ### Method Detail

    - #### init

          public void init(boolean forSigning,
                  CipherParameters param)

      Description copied from interface: `Signer`
      Initialise the signer for signing or verification.
      Specified by:
        `init` in interface `Signer`
      Parameters:
        `forSigning` - true if for signing, false otherwise
        `param` - necessary parameters.

    - #### update

          public void update(byte b)

      update the internal digest with the byte b
      Specified by:
        `update` in interface `Signer`

    - #### update

          public void update(byte[] in,
                    int off,
                    int len)

      update the internal digest with the byte array in
      Specified by:
        `update` in interface `Signer`

    - #### reset

          public void reset()

      reset the internal state
      Specified by:
        `reset` in interface `Signer`

    - #### generateSignature

          public byte[] generateSignature()
                                   throws CryptoException,
                                          DataLengthException

      generate a signature for the message we've been loaded with using the key we were initialised with.
      Specified by:
        `generateSignature` in interface `Signer`
      Throws:
        `CryptoException`
        `DataLengthException`

    - #### verifySignature

          public boolean verifySignature(byte[] signature)

      return true if the internal state represents the signature described in the passed in array.
      Specified by:
        `verifySignature` in interface `Signer`