Class IESEngine

java.lang.Object
org.bouncycastle.crypto.engines.IESEngine
Direct Known Subclasses:
OldIESEngine
public class IESEngine extends Object
Support class for constructing integrated encryption ciphers for doing basic message exchanges on top of key agreement ciphers. Follows the description given in IEEE Std 1363a.

  • Constructor Details

    • IESEngine

      public IESEngine(BasicAgreement agree, DerivationFunction kdf, Mac mac)
      Set up for use with stream mode, where the key derivation function is used to provide a stream of bytes to xor with the message.

      Security note: when this engine is initialised with static keys on both sides (the init(boolean, CipherParameters, CipherParameters, CipherParameters) entry point, which supplies no ephemeral component) the key-derivation input is the same for every message, so the stream-mode keystream is identical from message to message - encrypting more than one message under a given key pair is a many-time pad and leaks plaintext relationships. Use the ephemeral sender-key initialisation (the standard ECIES mode) for messages that must remain confidential; the static-static mode is effectively deterministic encryption.

      Parameters:
      agree - the key agreement used as the basis for the encryption
      kdf - the key derivation function used for byte generation
      mac - the message authentication code generator for the message

    • IESEngine

      public IESEngine(BasicAgreement agree, DerivationFunction kdf, Mac mac, BufferedBlockCipher cipher)
      Set up for use in conjunction with a block cipher to handle the message. It is strongly recommended that the cipher is not in ECB mode.
      Parameters:
      agree - the key agreement used as the basis for the encryption
      kdf - the key derivation function used for byte generation
      mac - the message authentication code generator for the message
      cipher - the cipher to used for encrypting the message

  • Method Details

    • init

      public void init(boolean forEncryption, CipherParameters privParam, CipherParameters pubParam, CipherParameters params)
      Initialise the encryptor.
      Parameters:
      forEncryption - whether or not this is encryption/decryption.
      privParam - our private key parameters
      pubParam - the recipient's/sender's public key parameters
      params - encoding and derivation parameters, may be wrapped to include an IV for an underlying block cipher.

    • init

      public void init(AsymmetricKeyParameter publicKey, CipherParameters params, EphemeralKeyPairGenerator ephemeralKeyPairGenerator)
      Initialise the decryptor.
      Parameters:
      publicKey - the recipient's/sender's public key parameters
      params - encoding and derivation parameters, may be wrapped to include an IV for an underlying block cipher.
      ephemeralKeyPairGenerator - the ephemeral key pair generator to use.

    • init

      public void init(AsymmetricKeyParameter privateKey, CipherParameters params, KeyParser publicKeyParser)
      Initialise the encryptor.
      Parameters:
      privateKey - the recipient's private key.
      params - encoding and derivation parameters, may be wrapped to include an IV for an underlying block cipher.
      publicKeyParser - the parser for reading the ephemeral public key.

    • getCipher

      public BufferedBlockCipher getCipher()

    • getMac

      public Mac getMac()

    • processBlock

      public byte[] processBlock(byte[] in, int inOff, int inLen) throws InvalidCipherTextException
      Throws:
      InvalidCipherTextException

    • getLengthTag

      protected byte[] getLengthTag(byte[] p2)