RFC 8446: The Transport Layer Security (TLS) Protocol Version 1.3

Publisher

IETF

URL

https://www.rfc-editor.org/rfc/rfc8446.html

Published

2018-08

Updated

unknown

Accessed

2026-09-25

HTTP status

200

License

IETF Trust Legal Provisions (BCP 78); no-redistribution; short excerpts and locators only

Source notes citing this source

• Because TLS 1.3 encrypts the Certificate messages, a plain packet capture of a TLS 1.3 SIP trunk cannot show whether the SBC sent its intermediates; Microsoft's capture-based check for a missing chain works directly only on TLS 1.2 sessions, and TLS 1.3 needs a key log or device-side debugs. inferred in context
• TLS defines distinct certificate alerts: bad_certificate (42), unsupported_certificate (43), certificate_revoked (44), certificate_expired (45, also sent for not-yet-valid certificates), certificate_unknown (46) and unknown_ca (48, for a chain that cannot be anchored in a trusted CA). in context
• In TLS 1.3 every handshake message after ServerHello is encrypted, including the Certificate messages. in context
• The TLS handshake_failure alert (40) means the sender could not negotiate an acceptable set of security parameters from the options offered. in context
• TLS signals an unsupported protocol version with protocol_version (70) and parameters judged too weak with insufficient_security (71); in TLS 1.3 a server that requires a client certificate and gets none sends certificate_required (116). in context

Cite this source record

APA

WarmTransfer. (n.d.). RFC 8446: The Transport Layer Security (TLS) Protocol Version 1.3. WarmTransfer. https://warmtransfer.net/knowledge/sources/rfc-8446-tls-1-3

BibTeX

@misc{warmtransfer-rfc-8446-tls-1-3,
  title  = {RFC 8446: The Transport Layer Security (TLS) Protocol Version 1.3},
  author = {{WarmTransfer}},
  year   = {2018},
  url    = {https://warmtransfer.net/knowledge/sources/rfc-8446-tls-1-3},
  note   = {IETF, accessed 2026-09-25}
}