CrunchyCrypt - Safe and Simple Cryptography

CrunchyCrypt is an opensource library offering safe and easy-to-use cryptography APIs with a built-in key-versioning protocol.

Table of Contents

• About CrunchyCrypt
• Codemap
• Compatibility guarantees
• License

Contact us at crunchy-discuss@googlegroups.com (link)

About CrunchyCrypt

CrunchyCrypt is an open-source collection of cryptography APIs, safe and easy-to-use wrappings of lower-level crypto libraries such as boringssl. Although CrunchyCrypt is intended to primarily be a curated collection of modern cryptography, CrunchyCrypt is designed to be extendable to both bleeding-edge and legacy cryptography.

CrunchyCrypt has a built-in key versioning protocol, where cryptographic payloads (signatures and ciphertexts) are (optionally) prefixed with a few bytes of key versioning information. This allows project owners to gracefully rotate new crunchy keys while maintaining backwards compatibility with old keys, even while switching the underlying algorithm.

Safety and ease-of-use are primary features of CrunchyCrypt, which is good for most, but not all, use cases. For example, user-specificed nonces is not something we intend to support. As a consequence, CrunchyCrypt is not meant to be a comprehensive replacement for openssl/boringssl.

Codemap

CrunchyCrypt supports crypto and key management in C++. CrunchyCrypt supports crypto in Java via JNI bindings.

CrunchyCrypt supports the following primitives in C++:

• AEAD Encryption Authenticated Encryption with Associated Data, aka symmetric encryption
  We support AES-GCM and AES-EAX at 128 and 256 bits of security.
• MACs Message authentication code, aka symmetric authentication
  We support HMAC-SHA256 with 16-byte tags and a 32-byte key.
• Digital Signatures, aka asymmetric authentication
  We support P256-ECDSA, Ed25519, and RSA-PKCS1 using SHA256 and a 2048-bit modulus.
• Hybrid Encryption, aka asymmetric encryption
  We support ECIES using HKDF and AEADs in various combinations, including versions using P256 and curve25519.

CrunchyCrypt supports key management in C++. CrunchyCrypt's built-in key-versioning protocol allows for graceful rotation of keys. KeysetManager is used to create, rotate, and delete keys. Serialization of unencrypted key material is in a separate keyset_serialization build target.

Java APIs for the above are implemented via JNI bindings.

Some internal APIs may be eventually made user-facing as we gain more experience as to how they might be used. For example, AdvancedKeysetManager and our subtle crypto APIs might be made non-internal if they're deemed useful.

Compatibility guarantees

We do not offer any ABI compatibility. We will strive to not break API compatibility. If we plan to break API compability, we will provide a migration path.

We ask that you:

• Don't open the crunchy namespace.
• Don't forward-declare crunchy types.
• Don't depend on internal details, namespaces or files that contain the word "internal".

License

CrunchyCrypt is licensed under the terms of the Apache License, Version 2.0. See LICENSE for more information.