# aws/s2n-tls

An implementation of the TLS/SSL protocols

Repository: https://github.com/aws/s2n-tls
Canonical: https://ross.abutalabs.com/products/s2n-tls
Homepage: https://aws.github.io/s2n-tls/usage-guide/
Language: C
License: Apache-2.0
License Family: permissive
Topics: tls, ssl, s2n, encryption, c, c99, cryptography, crypto
Last push: 2026-08-26T23:06:49+00:00

## Health v2 (maintenance only)
Score: 99/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 99, release rhythm 98, longevity 100
- inputs: {"age_days": 4450, "days_push": 7, "days_rel": 12, "gap_med": 15, "n_releases_24m": 40}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 4755, forks 798 (observed 2026-08-28T04:08:58.858227+00:00)

## What it is
s2n-tls is a C99 implementation of the TLS/SSL protocols designed to be simple, small, fast, and security-focused, maintained by AWS. It provides a C library with Rust bindings for adding encrypted TLS connections to applications and services.

## Use cases
- add TLS encryption to a C or Rust application
- embed a small fast TLS library in a service
- replace OpenSSL for TLS handshakes
- implement secure client and server connections
- audit a minimal TLS implementation for security review

## When to choose
- you need a compact, auditable TLS library in C or Rust
- you want a security-focused alternative to OpenSSL for TLS
- you're building AWS-style services needing lightweight TLS

## When to avoid
- you need a full-featured general-purpose crypto toolkit beyond TLS
- you need high-level language bindings other than Rust
- you want a turnkey HTTPS server rather than a library

## Facets
- artifact type: library
- maturity: stable
- function: cryptography, security, networking
- domain: security, developer-tools, networking
- platform: windows, cross-platform, c
- tags: tls, ssl, c99, encryption, rust-bindings, aws, linux, macos

## Member repositories
- aws/s2n-tls (main) score 99

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:08:58.858227+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T18:18:53.921321+00:00, confidence not recorded.
  - readme: https://github.com/aws/s2n-tls (fetched 2026-08-28T04:08:58.858227+00:00, sha 42410e056039)
  - homepage: https://aws.github.io/s2n-tls/usage-guide/ (fetched 2026-08-29T09:02:17.963268+00:00, sha a90df88759e6)
- Data as of 2026-08-30T08:39:29.467469+00:00.