Package zeroecho.sdk.util

package zeroecho.sdk.util
Utility helpers for provider setup, key derivation, randomness, encoding, and X.509 handling.

This package gathers small, focused utilities used across the SDK: activation of Bouncy Castle providers, RFC 5869 HKDF helpers, adapters that expose output-style transforms as readable streams, streaming decoders for length-prefixed payloads, password helpers, random-byte support, and simple X.509 PEM utilities.

Key elements

  • BouncyCastleActivator - one-time registration of Bouncy Castle providers. A static initializer adds providers; BouncyCastleActivator.init() can be called explicitly to confirm activation.
  • Kdf - HKDF-SHA-256 derivation utilities for producing symmetric keys from KEM or agreement secrets.
  • OutputToInputStreamAdapter - base class that adapts an OutputStream driven transformation into an InputStream; subclasses provide the transforming output and the adapter exposes transformed bytes as they become available.
  • Pack7LStreamWriter - incremental writer that consumes a 7-bit packed length prefix, then copies exactly that many payload bytes to a target stream.
  • Password - helpers for generating random bytes and printable passwords.
  • X509Support - minimal PEM-based load and print helpers for certificates, private keys, and certificate signing requests.

Typical usage

// Ensure Bouncy Castle providers are present.
zeroecho.sdk.util.BouncyCastleActivator.init();

// Derive 32 bytes with HKDF-SHA-256 for a symmetric key.
byte[] key = zeroecho.sdk.util.Kdf.hkdfSha256(ikm, salt, info, 32);

Design notes

  • Utilities avoid retaining sensitive material and prefer cloning caller arrays where appropriate.
  • Streaming adapters do not buffer whole payloads except where transform semantics require it.
  • Provider setup is explicit and emits concise diagnostics to aid development.
Since:
1.0
  • Classes
    Class
    Description
    BikeKeySupport
    BIKE-256 key pair utilities for modules that depend on zeroecho.lib.
    BouncyCastleActivator
    Provides initialization support for the Bouncy Castle cryptographic provider.
    Kdf
    HKDF utilities for deriving symmetric keys from a KEM shared secret.
    OutputToInputStreamAdapter
    An abstract adapter that converts an OutputStream-based transformation (such as encryption or compression) into an InputStream-based one.
    Pack7LStreamWriter
    A streaming writer that reads a variable-length 7-bit encoded length prefix from the input data and writes the subsequent payload to a target OutputStream.
    Password
    Utility class for generating random passwords and secure random byte arrays.
    X509Support
    Utility class providing support for working with X.509 certificates, private keys, and certification requests using PEM-encoded files and the Bouncy Castle library.