One-KVM patches only certificate-chain verification and its configuration to use vendored OpenSSL instead of rustls/WebPKI. DTLS flights, record protection, certificate signatures, SRTP negotiation and the application fingerprint check remain unchanged. rustls-pki-types remains a certificate-data representation, not a TLS implementation.

certificate_verifier.rs implements trust-anchor, purpose, certificate-validity and DNS/IP identity checks. Server names do not fall back to the certificate subject, and partial-label wildcards are rejected. No trust checks are skipped by this backend. The upstream application-controlled insecure_skip_verify policy is preserved, including WebRTC's separate certificate fingerprint check. Authentication security level 2 rejects weak RSA keys and SHA-1 leaf signatures.

Run cargo test --manifest-path libs/dtls/Cargo.toml --lib after updating this fork, and verify the application dependency tree contains no rustls engine.