What is axTLS?
axTLS is an open-source, embedded SSL/TLS library intended for developers who need secure communication capabilities on devices with constrained memory resources. The library supports TLS versions 1.0 through 1.2 and focuses on efficiency, with a core library size of only 50-60kB in server-only mode. axTLS is written in ANSI C and provides cross-platform compatibility, being tested on Linux, Win32, and Cygwin environments.
It features session resumption to boost SSL performance, supports high-strength AES encryption and SHA digests, and allows flexible RSA key sizes. The library includes a minimalist API, peer verification, certificate chaining, and session renegotiation. Compilation is highly customizable, and interfaces for multiple programming languages are provided, making axTLS a practical choice for secure communications in embedded and resource-limited applications.
Features
- Small Footprint: Only 50-60kB in server-only mode
- TLS Support: TLSv1.0, TLSv1.1, and TLSv1.2 protocols
- Session Resumption: Ensures high SSL performance
- Strong Encryption: Supports AES128/AES256 and SHA256/SHA384/SHA512
- Cross-Platform: Compatible with Linux, Win32, and Cygwin
- Variable RSA Key Sizes: Supports 512 to 4096 bits
- Simple API: Minimalistic set of C functions
- Certificate Handling: X509v1, PKCS#8, PKCS#12 in DER/PEM formats
- Highly Configurable: Extensive compile-time options
- Multi-Language Interfaces: C#, VB.NET, Java, Perl, and Lua support
Use Cases
- Secure communication for IoT and embedded devices
- Lightweight HTTPS servers on constrained hardware
- Integrating TLS encryption into custom network applications
- Rapid prototyping of secure client/server models
- Educational purposes in secure software development
FAQs
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Which TLS versions does axTLS support?
axTLS supports TLSv1.0, TLSv1.1, and TLSv1.2 protocols. -
What cryptographic algorithms are available in axTLS?
axTLS offers AES128, AES256 for encryption and SHA256, SHA384, SHA512 for digests. -
What is the typical library size of axTLS in server-only mode?
The axTLS library requires about 50-60kB in server-only mode. -
Can axTLS be used with languages other than C?
Yes, axTLS provides interfaces for C#, VB.NET, Java, Perl, and Lua.
