5 Standards Compliance

5.1 Purpose

This section describes the current state of standards compliance of the ssl application.

5.2 Common (pre TLS 1.3)

• For security reasons RSA key exchange cipher suites are no longer supported by default, but can be configured. (OTP 21)
• For security reasons DES cipher suites are no longer supported by default, but can be configured. (OTP 20)
• For security reasons 3DES cipher suites are no longer supported by default, but can be configured. (OTP 21)
• Renegotiation Indication Extension RFC 5746 is supported
• Ephemeral Diffie-Hellman cipher suites are supported, but not Diffie Hellman Certificates cipher suites.
• Elliptic Curve cipher suites are supported if the Crypto application supports it and named curves are used.
• Export cipher suites are not supported as the U.S. lifted its export restrictions in early 2000.
• IDEA cipher suites are not supported as they have become deprecated by the TLS 1.2 specification so it is not motivated to implement them.
• Compression is not supported.

5.3 Common

• CRL validation is supported.
• Policy certificate extensions are not supported.
• 'Server Name Indication' extension (RFC 6066) is supported.
• Application Layer Protocol Negotiation (ALPN) and its successor Next Protocol Negotiation (NPN) are supported.
• It is possible to use Pre-Shared Key (PSK) and Secure Remote Password (SRP) cipher suites, but they are not enabled by default.

5.4 ssl 2.0

For security reasons SSL-2.0 is not supported. Interoperability with SSL-2.0 enabled clients dropped. (OTP 21)

5.5 ssl 3.0

For security reasons SSL-3.0 is no longer supported at all. (OTP 23)

For security reasons SSL-3.0 is no longer supported by default, but can be configured. (OTP 19)

5.6 tls 1.0

For security reasons TLS-1.0 is no longer supported by default, but can be configured. (OTP 22)

5.7 tls 1.1

For security reasons TLS-1.1 is no longer supported by default, but can be configured. (OTP 22)

5.8 tls 1.2

Supported

5.9 dtls 1.0

For security reasons DTLS-1.0 (based on TLS 1.1) is no longer supported by default, but can be configured. (OTP 22)

5.10 dtls 1.2

Supported (based on TLS 1.2)

5.11 dtls 1.3

Not yet supported

5.12 tls 1.3

OTP-22 introduces support for TLS 1.3. The current implementation supports a selective set of cryptographic algorithms:

• Key Exchange: ECDHE
• Groups: all standard groups supported for the Diffie-Hellman key exchange
• Ciphers: all cipher suites are supported
• Signature Algorithms: All algorithms form RFC 8446
• Certificates: RSA, ECDSA and EDDSA keys

Other notable features:

• PSK and session resumption is supported (stateful and stateless tickets)
• Anti-replay protection using Bloom-filters with stateless tickets
• Early data and 0-RTT is supported
• Key and Initialization Vector Update is supported

For more detailed information see the Standards Compliance below.

The following table describes the current state of standards compliance for TLS 1.3.

(C = Compliant, NC = Non-Compliant, PC = Partially-Compliant, NA = Not Applicable)