Extend HMAC metadata and builders to expose recommended key sizes and
enable safe derived-key injection without duplicating algorithm
configuration.
Key changes:
- Add HybridDerived utility for expanding hybrid KEX output and
injecting purpose-separated keys, IVs/nonces and optional AAD into
existing DataContent builders (AES-GCM, ChaCha, HMAC)
- Improve HmacSpec and HmacDataContentBuilder to expose recommended key
material characteristics for derived use
- Refine HybridKexContexts to better support exporter-based derived
workflows
- Add comprehensive unit tests for hybrid-derived functionality
- Add documented demo showing hybrid-derived AES-GCM encryption,
including local (self-recipient) hybrid usage
- Introduce top-level sdk.hybrid package documentation and derived
subpackage Javadoc
All changes are additive at the SDK layer; core cryptographic contracts
remain unchanged.
Signed-off-by: Leo Galambos <lg@hq.egothor.org>
Introduce a complete SDK-level hybrid KEX framework combining classic
(DH/ECDH/XDH) and post-quantum (KEM adapter) agreement contexts.
Key additions:
- HybridKexContext and HybridKexContexts for hybrid handshake
orchestration over existing AgreementContext and
MessageAgreementContext APIs
- HybridKexProfile, HybridKexTranscript and HybridKexExporter providing
HKDF-based key derivation, transcript binding and key schedule support
- HybridKexPolicy for optional security strength and output-length
gating
- HybridKexBuilder offering a fluent, professional API for constructing
CLASSIC_AGREEMENT + KEM_ADAPTER and PAIR_MESSAGE + KEM_ADAPTER
variants
- Comprehensive JUnit tests and documented demo illustrating both hybrid
modes
No changes to core cryptographic APIs; all hybrid logic is implemented
as additive functionality in the SDK layer.
Signed-off-by: Leo Galambos <lg@hq.egothor.org>
Introduce GenericJcaMessageAgreementContext and KeyPairKey to support
message-based key agreement without breaking existing AgreementContext
capabilities.
Key changes:
- Add KeyPairKey wrapper to carry KeyPair through capability dispatch.
- Introduce GenericJcaMessageAgreementContext implementing
MessageAgreementContext, mapping the protocol message to an
SPKI-encoded public key.
- Extend DH, ECDH and XDH algorithms with an additional
MessageAgreementContext capability while preserving existing
PrivateKey-based agreement usage.
- Improve core agreement tests to cover CLASSIC_AGREEMENT, PAIR_MESSAGE
and KEM_ADAPTER variants with explicit branch identification.
- Add demo samples illustrating practical usage patterns for ML-KEM and
XDH agreement variants, including lifecycle and resource management
guidance.
This change adds capabilities by extension rather than replacement and
keeps existing APIs and behaviors fully backward compatible.
Signed-off-by: Leo Galambos <lg@hq.egothor.org>
Add a complete hybrid signature implementation combining two independent
signature algorithms with AND/OR verification semantics, designed for
streaming pipelines.
Key changes:
- Add zeroecho.sdk.hybrid.signature package with core hybrid signature
abstractions (HybridSignatureContext, HybridSignatureProfile,
factories, predicates, and package documentation).
- Introduce SignatureTrailerDataContentBuilder as a
signature-specialized replacement for
TagTrailerDataContentBuilder<Signature>, supporting
core, single-algorithm, and hybrid signature construction.
- Extend sdk.builders package documentation to reference the new
signature trailer builder and newly added PQC signature builders.
- Adjust TagEngineBuilder where required to support hybrid verification
integration.
- Update JUL configuration to accommodate hybrid signature diagnostics
without leaking sensitive material.
Tests and samples:
- Add comprehensive JUnit 5 tests covering hybrid signatures in all
supported modes, including positive and negative cases.
- Add a dedicated sample demonstrating hybrid signing combined with AES
encryption (StE and EtS).
- Update existing signing samples to reflect the new signature trailer
builder.
The changes introduce a unified, extensible hybrid signature model
without breaking existing core APIs or pipeline composition patterns.
Signed-off-by: Leo Galambos <lg@hq.egothor.org>
