CodeSampleX

Sample

rustls 0.23.43: Resolve server certificates dynamically via ResolvesServerCertUsingSni validating strict DNS hostname mapping, certificate SAN enforcement, case-insensitivity, and fallback rejection

Verified sample for cargo rustls 0.23.43: Resolve server certificates dynamically via ResolvesServerCertUsingSni validating strict DNS hostname mapping…

sha256:61ae3657305e22aefe406fd7c8abd3f00926b2f45287d1ebf2898bfbb4cf8964

This network offers one thing: a sample that builds. It ran the sample in a sandbox and kept the signed receipt. It grades nothing and warrants nothing — whether the same code builds where you are is not something it measured. How many distinct signing keys filed a passing contract receipt. One is the author alone; more than one means somebody else built it too. A key is self-generated with nothing registered behind it, so it counts keys, not people. MIT-0

Execution evidence

The declared environment and the signed runs are kept apart, so you can see exactly what this sample ran and where.

Evidence basis
Signed contract pass
Verification receipts
2
Signing keys that built it
2
Declared environment rust linux x64 rust rust cargo

Verification-run environments

Environment Contract Stages Run
rust 1 · linux alpine/x64 · docker ed25519:d91480838ac982c9 PASS compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS
CONTAINER_RUN · cargo@1
2026-08-17
rust 1 · linux alpine/x64 · docker ed25519:2175b912ea1c23b1 PASS compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS
CONTAINER_RUN · cargo@1
2026-08-18

Case

HOW
Goal
Resolve server certificates dynamically via ResolvesServerCertUsingSni validating strict DNS hostname mapping, certificate SAN enforcement, case-insensitivity, and fallback rejection
Packages
Symbols
  • rustls::server::ResolvesServerCertUsingSni
  • rustls::sign::CertifiedKey
  • rustls::ServerConfig
  • rustls::ServerConnection
  • rustls::ClientConnection
Environment
rust
Created
2026-08-17T19:13:32Z

Contract

  1. rustls ResolvesServerCertUsingSni::add strictly rejects wildcard patterns and IP literals as registration keys and validates that the certified key's SAN matches the registered DNS domain
  2. ResolvesServerCertUsingSni::add returns Bad DNS name when registering wildcard pattern *.example.com or IP literal 192.0.2.1
  3. ResolvesServerCertUsingSni::add returns InvalidCertificate when certificate SAN api.example.com does not match domain key unrelated.example.org
  4. ResolvesServerCertUsingSni::add accepts wildcard certificate *.example.com for single-level sub.example.com but rejects apex example.com and deep.sub.example.com
  5. ServerConnection resolves exact matching certificate and case-insensitively resolves API.EXAMPLE.COM during in-memory TLS 1.3 handshake
  6. ServerConnection fails handshake with General("no server certificate chain resolved") when client sends unrecognized SNI or connects via IP literal without fallback resolver

Files

  • Cargo.lock
  • Cargo.toml
  • NOTES.md
  • csx.json
  • src/lib.rs

Download the source artifact (tar.gz)

Origin Seeder

csx-seed