$cipher()

Synopsis

$cipher([<refnum>])

Technical

Returns the cipher name reported by OpenSSL for the TLS connection associated with server <refnum>. This reports connection information; it does not select or change a cipher.

Omitting <refnum> uses the server in the current execution context. An explicit argument is a numeric server reference number, not a server name. Negative reference numbers, including -1, return an empty string rather than selecting the current server. Additional arguments are ignored.

Returns

Returns the result of SSL_get_cipher_name() for the connection's TLS session. Returns an empty string for an invalid server reference, a connection without TLS state, or missing TLS session state. Before a cipher has been negotiated, the value is whatever OpenSSL reports for that session.

Restrictions

The function is always registered in current EPIC builds, which require OpenSSL. A cipher name alone does not report certificate verification or prove the identity of the remote server.

Examples

 echo Current connection cipher: $cipher()
 echo Server 0 cipher: $cipher(0)

The second example returns an empty string if server 0 has no TLS connection state.

History

The $cipher() function first appeared in EPIC4-1.1.3.

Source

Registered and implemented in source/functions.c. Server connection lookup is in source/server.c, and the OpenSSL query is in source/ssl.c. The OpenSSL build requirement is in configure.ac.