SAMLassertie

SAMLassertie is a lightweight library designed to simplify the creation, parsing, and validation of Security Assertion Markup Language (SAML) authentication assertions within web applications. Developed in 2019 by an open‑source community of identity‑management engineers, the project was introduced to address gaps in existing SAML tooling, notably the difficulty of integrating SAML assertions into modern microservices architectures.

The core functionality of SAMLassertie revolves around three main components. First, the Assertion Builder enables developers to programmatically construct SAML assertions from application‑specific claims, supporting both SAML 1.1 and SAML 2.0 specifications. Second, the Assertion Parser provides robust XML parsing with schema validation against the official SAML metadata schemas, ensuring that corrupt or malformed assertions trigger clear error messages. Third, the Assertion Verifier handles cryptographic signature verification, supporting RSA/SHA‑256, DSA, and ECDSA key types, as well as optional timestamp checks to guard against replay attacks.

SAMLassertie is distributed under the Apache License 2.0 and is hosted on GitHub, where contributions are accepted via pull requests. The current stable release, version 2.3.1, incorporates performance improvements and extended support for Service Provider (SP) metadata generation. Adoption of the library is evident in several start‑ups that require secure single‑sign‑on (SSO) integration across cloud‑based SaaS products. Future roadmap items include native support for SAML Assertion Query across web services and integration with popular JavaScript frameworks for client‑side assertion handling.