Package zeroecho.core.alg.dh

package zeroecho.core.alg.dh
Diffie-Hellman (DH) algorithm integration.

This package provides the core support for Diffie-Hellman key agreement within the ZeroEcho framework. It includes the algorithm descriptor, a builder for generating key pairs, immutable parameter specifications, and encoded key specs for import/export. The implementation favors use of standardized RFC 7919 finite-field DH groups and encapsulates JCA interoperability.

Scope and responsibilities

  • Register the DH algorithm with a canonical identifier and declare its KeyUsage.AGREEMENT capability.
  • Provide a builder for generating key pairs from known parameter sets or ad-hoc parameter generation.
  • Expose predefined RFC 7919 FFDHE groups for safe parameter selection.
  • Allow import/export of encoded keys via defensively copying key specs supporting PKCS#8 and X.509; private-key specs are destroyable.

Components

  • DhAlgorithm: registers the algorithm under id "DH", binds agreement contexts to the JCA "DiffieHellman" implementation, and wires key builders.
  • DhKeyGenBuilder: generates key pairs using AlgorithmParameterGenerator or supplied DHParameterSpec instances.
  • DhSpec: immutable container for DH parameters; provides static factories for FFDHE groups (2048–8192 bits).
  • DhPublicKeySpec and DhPrivateKeySpec: encoded key specs for importing/exporting X.509 and PKCS#8 encodings, with PairSeq marshalling support; the private-key form is destroyable.

Design notes

  • Algorithm descriptors are immutable and thread-safe for reuse.
  • Builders are stateless; contexts produced for key agreement are not thread-safe and should be used per operation.
  • Use of standardized groups is strongly recommended over ad-hoc parameter generation for interoperability and safety.
Since:
1.0
  • Classes
    Class
    Description
    DhAlgorithm
    Diffie-Hellman algorithm registration for use in the pluggable cryptography catalog.
    DhKeyGenBuilder
    DH key pair builder
    DhPrivateKeySpec
    Key specification for a Diffie-Hellman private key encoded in PKCS#8 format.
    DhPublicKeySpec
    Key specification for a Diffie-Hellman public key encoded in X.509 format.
    DhSpec
    Diffie-Hellman parameter specification