This repository is a Java library for JSON Web Token (JWT) handling per RFC 7519. It provides comprehensive functionality for creating, signing, verifying, and decoding JWTs, supporting multiple cryptographic algorithms including HMAC (HS256/384/512), RSA (RS256/384/512, PS256/384/512), EC (ES256/384/512), and EdDSA (Ed25519/Ed448). The library also includes utilities for JSON Web Key (JWK) management, PEM encoding/decoding of keys and certificates, and ASN.1 DER parsing for low-level cryptographic operations. Architecturally, the library follows a modular structure with clear separation of concerns: core JWT operations in the `jwt` package, JWK handling in `jwks`, PEM utilities in `pem`, and DER parsing in `der`. Cryptographic operations are abstracted through `Signer` and `Verifier` interfaces, enabling the Strategy pattern for pluggable algorithm implementations. Object creation uses the Builder pattern for immutable, fluent APIs (e.g., `JWT.addClaim()`, `KeyPair.build()`). JSON processing is centralized via a configured Jackson `Mapper` with custom serializers/deserializers for Java 8+ date-time types. The design minimizes coupling, allowing components like `JWTUtils` or `HMACSigner` to be reused independently. The library is actively maintained, with recent commits (2026-07-15) and ongoing security updates (e.g., patches for CVE-2022-21449). Dependencies are managed via Maven/Savant, relying primarily on Jackson for JSON processing with optional Bouncy Castle for certain algorithms. The codebase demonstrates strong engineering practices: comprehensive unit tests cover all algorithms and edge cases, clear exception hierarchies provide specific error handling, and Java 9+ module system support is included. It serves as a robust, reusable foundation for any Java application requiring secure token-based authentication or authorization.
This repository is a .NET library for JWT (JSON Web Token) key management that provides automatic generation and rotation of cryptographic keys for JWT signing (JWS) and encryption (JWE). It features a modular architecture with a core library handling key generation/storage, multiple storage providers (in-memory, file system, Entity Framework Core), and framework-specific integrations for ASP.NET Core and IdentityServer4. The library exposes a JWKS endpoint for sharing public keys and integrates with ASP.NET Core authentication systems to validate tokens using the managed keys. Key entry points include the AddJwksManager() service registration method, UseJwksDiscovery() middleware for the JWKS endpoint, and the IJwtService interface for token generation and validation. The primary data flow involves generating cryptographic keys, storing them via pluggable storage providers, retrieving current keys for token operations, and exposing public keys through the JWKS endpoint. The library depends on System.IdentityModel.Tokens.Jwt for JWT handling, Microsoft.AspNetCore.DataProtection for key protection in the default storage implementation, and various Microsoft.Extensions packages for caching, options, and logging.
This repository provides a WebCrypto API polyfill for Node.js, implementing the W3C Web Cryptography API using Node's native crypto module. It supports a comprehensive set of algorithms including AES (CBC, CTR, GCM, ECB, KW, CMAC), DES (CBC, EDE3-CBC), RSA (SSA, PSS, OAEP, ES), ECDSA, ECDH, EdDSA, ECDH-ES, Ed25519, X25519, HMAC, PBKDF2, HKDF, SHA-1/256/384/512, SHA3-256/384/512, and SHAKE128/256. The architecture follows a provider pattern where each algorithm is implemented as a separate class extending a base provider from the 'webcrypto-core' library. Key management is handled through internal CryptoKey classes with serialization support for JWK, raw, PKCS8, and SPKI formats. The library is designed as a drop-in replacement for the browser's crypto.subtle API, enabling isomorphic JavaScript cryptography.
This repository is the official code companion to the book '50 ML projects to understand LLMs' by Mike X Cohen. It contains over 50 Jupyter notebooks organized into chapters (2–7), each exploring a specific concept in large language model interpretability and internals. Topics span tokenization, embeddings, cosine similarity, softmax/logits, loss functions, sampling, hidden state analysis, effective dimensionality, logit lens, attention mechanisms, MLP projections, probing classifiers, and bias measurement. The code is purely educational and experimental—no production services, APIs, or deployable applications. All notebooks are designed to run on Google Colab with minimal setup, using standard libraries (PyTorch, Hugging Face Transformers, scikit-learn, numpy, matplotlib) and pretrained models (GPT-2, BERT, RoBERTa, Pythia). Each project has a 'helper' notebook (incomplete code for students) and a 'solution' notebook (complete reference implementation). The repository is a valuable resource for learning mechanistic interpretability and hands-on LLM analysis, but it lacks modularization, dependency pinning, and test coverage, making it unsuitable for direct reuse in production pipelines.