[TS-2557] Adopt resumable TLS session API

• Type: New Feature
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Fix Version/s: sometime
• Component/s: Security, SSL
• Assignee: Susan Hinrichs
• Reporter: James Peach
• Created: 07/Feb/14 05:56
• Updated: 16/Aug/16 16:20

Description

In OpenSSL 1.1.0 adds a new callback API for applications to control whether the TLS session should be cached or not.

void SSL_CTX_set_not_resumable_session_callback(SSL_CTX *ctx, int (*cb)(SSL *ssl, int is_forward_secure))
void SSL_set_not_resumable_session_callback(SSL *ssl, int (*cb)(SSL *ssl, int is_forward_secure))

for use by SSL/TLS servers; the callback function will be called whenever a
new session is created, and gets to decide whether the session may be
cached to make it resumable (return 0) or not (return 1). (As by the
SSL/TLS protocol specifications, the session_id sent by the server will be
empty to indicate that the session is not resumable; also, the server will
not generate RFC 4507 (RFC 5077) session tickets.)

A simple reasonable callback implementation is to return is_forward_secure.
This parameter will be set to 1 or 0 depending on the ciphersuite selected
by the SSL/TLS server library, indicating whether it can provide forward
security.

This seems like a useful sort of option.