Package zeroecho.core.alg.common.eddsa

package zeroecho.core.alg.common.eddsa

EdDSA (Edwards-curve Digital Signature Algorithm) key builders and contexts.

This package provides common infrastructure for Ed25519 and Ed448 algorithm support. It focuses on key-pair generation, importing encoded keys, and wiring EdDSA variants into the generic signature context API.

Scope and responsibilities

• Provide abstract builders for EdDSA key-pair generation and encoded key import.
• Offer an abstract signature context that binds an EdDSA variant to the generic JCA-based signature context, with fixed tag lengths.
• Keep provider-specific concerns encapsulated in small, composable building blocks.

Components

• Key generation: AbstractEdDSAKeyGenBuilder integrates with KeyPairGenerator to produce new Ed25519/Ed448 key pairs.
• Private key import: AbstractEncodedPrivateKeyBuilder reconstructs private keys from PKCS#8 encodings via KeyFactory.
• Public key import: AbstractEncodedPublicKeyBuilder reconstructs public keys from X.509 encodings via KeyFactory.
• Signature contexts: CommonEdDSASignatureContext delegates all operations to a generic JCA-backed signature adapter, enforcing a fixed tag length for the selected EdDSA variant.

Design notes

• Builders are stateless and safe for concurrent use; each import or generation creates a fresh JCA engine internally.
• Import methods intentionally throw for unsupported directions (e.g., public import in the private builder) to keep responsibilities clear.
• Signature contexts are not thread-safe; they are expected to be used for a single signing or verification stream at a time.

Since:

1.0

Classes

Class	Description
AbstractEdDSAKeyGenBuilder<S extends AlgorithmKeySpec>	Abstract EdDSA Key-Pair Builder
AbstractEncodedPrivateKeyBuilder<S extends AlgorithmKeySpec>	Abstract EdDSA Encoded Private Key Builder
AbstractEncodedPublicKeyBuilder<S extends AlgorithmKeySpec>	Abstract EdDSA Encoded Public Key Builder
CommonEdDSASignatureContext	Base class for EdDSA signature contexts that adapts a JCA Signature for streaming sign and verify.