Add DH AlgorithmParameters, AlgorithmParameterGenerator, KeyFactory, and related fixes

[cconlon]

This PR adds DH AlgorithmParameters, AlgorithmParameterGenerator, and KeyFactory implementations as well as fixes some KeyAgreement implementation issues to match SunJCE behavior.

New DH Components

• AlgorithmParameters: WolfCryptDhParameters - Encode/decode DH parameters using ASN.1
• AlgorithmParameterGenerator: WolfCryptDhParameterGenerator - Generate DH domain parameters (p, g)
• KeyFactory: WolfCryptDHKeyFactory - Convert between DH key specs (DHPublicKeySpec, DHPrivateKeySpec, X509EncodedKeySpec, PKCS8EncodedKeySpec)
• Public/Private Key implementations: WolfCryptDHPublicKey and WolfCryptDHPrivateKey

JNI Layer

• Added support for parameter generation, key generation, and shared secret computation in jni_dh.c

KeyAgreement Fixes

1. SecretKey generation (engineGenerateSecret(String)): Now returns SecretKeySpec instead of incorrectly casting DESKeySpec/DESedeKeySpec to SecretKey interface. Added proper AES key size handling (128/192/256-bit).
2. DH padding (engineGenerateSecret(byte[], int)): Pad DH shared secrets to prime length with leading zeros per JDK-7146728, matching SunJCE post-Java 8 behavior and RFC 2631 (2.1.2).

Test Coverage

• WolfCryptDHKeyFactoryTest: added DH KeyFactory tests
• WolfCryptAlgorithmParametersTest: testing DH parameter encoding/decoding
• WolfCryptAlgorithmParameterGeneratorTest: testing parameter generation
• WolfCryptASN1UtilTest: testing ASN.1 utilities
• WolfCryptKeyAgreementTest: Added testDHKeyAgreementPadding() regression test and updated existing tests for AES key generation
• WolfCryptKeyPairGeneratorTest: Added DH-specific tests

Other Changes

• Updated CLAUDE.md with XMALLOC usage
• Updated README_JCE.md documenting new DH support
• Added new files to scripts/infer.sh for static analysis
• Registered new services in WolfCryptProvider

[Copilot]

Pull Request Overview

This PR adds comprehensive DH (Diffie-Hellman) support to wolfJCE by implementing AlgorithmParameters, AlgorithmParameterGenerator, and KeyFactory, along with fixing KeyAgreement implementation issues to match SunJCE behavior.

Key changes:

• Implemented DH AlgorithmParameters for encoding/decoding DH parameters using ASN.1
• Added DH AlgorithmParameterGenerator supporting both FFDHE standard groups and dynamic parameter generation
• Created DH KeyFactory with support for key conversion between various KeySpec formats
• Fixed KeyAgreement secret key generation and DH padding behavior to match SunJCE post-Java 8

Reviewed Changes

Copilot reviewed 24 out of 24 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
WolfCryptProvider.java	Registered new DH services (AlgorithmParameters, AlgorithmParameterGenerator, KeyFactory)
Dh.java	Added native methods and constants for FFDHE groups, parameter generation, and key operations
WolfCryptKeyPairGenerator.java	Added default FFDHE parameter initialization and FFDHE key size support for DH
WolfCryptKeyAgreement.java	Fixed DH padding and secret key generation to match SunJCE behavior
WolfCryptDhParameters.java	New class implementing DH AlgorithmParameters with ASN.1 encoding/decoding
WolfCryptDhParameterGenerator.java	New class for generating DH parameters using FFDHE groups or dynamic generation
WolfCryptDHKeyFactory.java	New class for DH key conversion between KeySpec formats
WolfCryptDHPublicKey.java	New class implementing DHPublicKey with X.509 encoding
WolfCryptDHPrivateKey.java	New class implementing DHPrivateKey with PKCS#8 encoding
WolfCryptASN1Util.java	New utility class for ASN.1/DER encoding operations
jni_dh.c	Added JNI implementations for new DH operations
jni_aesgcm.c	Fixed constant name from WC_AES_BLOCK_SIZE to AES_BLOCK_SIZE
jni_aesccm.c	Fixed constant name from WC_AES_BLOCK_SIZE to AES_BLOCK_SIZE
Test files	Added comprehensive test coverage for new DH functionality
Documentation	Updated README_JCE.md and CLAUDE.md with new features and guidelines

Comments suppressed due to low confidence (1)

jni/jni_dh.c:1

• The changes to jni_aesgcm.c and jni_aesccm.c replace WC_AES_BLOCK_SIZE with AES_BLOCK_SIZE. Verify that AES_BLOCK_SIZE is defined in the wolfSSL version being used, as WC_AES_BLOCK_SIZE is the standard wolfSSL constant name. If AES_BLOCK_SIZE is not available in older wolfSSL versions, this could cause compilation failures.

/* jni_dh.c

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