SSL_CTX_set_mode - manipulate SSL engine mode
#include <openssl/ssl.h> long SSL_CTX_set_mode(SSL_CTX *ctx, long mode); long SSL_set_mode(SSL *ssl, long mode); long SSL_CTX_get_mode(SSL_CTX *ctx); long SSL_get_mode(SSL *ssl);
OpenSSL SSL_CTX_set_mode(3openssl)
NAME
SSL_CTX_set_mode, SSL_set_mode, SSL_CTX_get_mode, SSL_get_mode -
manipulate SSL engine mode
SYNOPSIS
#include <openssl/ssl.h>
long SSL_CTX_set_mode(SSL_CTX *ctx, long mode);
long SSL_set_mode(SSL *ssl, long mode);
long SSL_CTX_get_mode(SSL_CTX *ctx);
long SSL_get_mode(SSL *ssl);
DESCRIPTION
SSL_CTX_set_mode() adds the mode set via bitmask in mode to ctx.
Options already set before are not cleared.
SSL_set_mode() adds the mode set via bitmask in mode to ssl. Options
already set before are not cleared.
SSL_CTX_get_mode() returns the mode set for ctx.
SSL_get_mode() returns the mode set for ssl.
ATTRIBUTES
See attributes(7) for descriptions of the following attributes:
+---------------+--------------------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+---------------+--------------------------+
|Availability | library/security/openssl |
+---------------+--------------------------+
|Stability | Pass-through uncommitted |
+---------------+--------------------------+
NOTES
The following mode changes are available:
SSL_MODE_ENABLE_PARTIAL_WRITE
Allow SSL_write(..., n) to return r with 0 < r < n (i.e. report
success when just a single record has been written). When not set
(the default), SSL_write() will only report success once the
complete chunk was written. Once SSL_write() returns with r, r
bytes have been successfully written and the next call to
SSL_write() must only send the n-r bytes left, imitating the
behaviour of write().
SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER
Make it possible to retry SSL_write() with changed buffer location
(the buffer contents must stay the same). This is not the default
to avoid the misconception that non-blocking SSL_write() behaves
like non-blocking write().
SSL_MODE_AUTO_RETRY
Never bother the application with retries if the transport is
blocking. If a renegotiation take place during normal operation, a
SSL_read(3) or SSL_write(3) would return with -1 and indicate the
need to retry with SSL_ERROR_WANT_READ. In a non-blocking
environment applications must be prepared to handle incomplete
read/write operations. In a blocking environment, applications are
not always prepared to deal with read/write operations returning
without success report. The flag SSL_MODE_AUTO_RETRY will cause
read/write operations to only return after the handshake and
successful completion.
SSL_MODE_RELEASE_BUFFERS
When we no longer need a read buffer or a write buffer for a given
SSL, then release the memory we were using to hold it. Released
memory is either appended to a list of unused RAM chunks on the
SSL_CTX, or simply freed if the list of unused chunks would become
longer than SSL_CTX->freelist_max_len, which defaults to 32. Using
this flag can save around 34k per idle SSL connection. This flag
has no effect on SSL v2 connections, or on DTLS connections.
SSL_MODE_SEND_FALLBACK_SCSV
Send TLS_FALLBACK_SCSV in the ClientHello. To be set only by
applications that reconnect with a downgraded protocol version; see
draft-ietf-tls-downgrade-scsv-00 for details.
DO NOT ENABLE THIS if your application attempts a normal handshake.
Only use this in explicit fallback retries, following the guidance
in draft-ietf-tls-downgrade-scsv-00.
Source code for open source software components in Oracle Solaris
can be found at
https://www.oracle.com/downloads/opensource/solaris-source-code-
downloads.html.
This software was built from source available at
https://github.com/oracle/solaris-userland. The original community
source was downloaded from
https://www.openssl.org/source/openssl-1.0.2ze.tar.gz.
Further information about this software can be found on the open
source community website at https://www.openssl.org/.
RETURN VALUES
SSL_CTX_set_mode() and SSL_set_mode() return the new mode bitmask after
adding mode.
SSL_CTX_get_mode() and SSL_get_mode() return the current bitmask.
SEE ALSO
ssl(3), SSL_read(3), SSL_write(3)
HISTORY
SSL_MODE_AUTO_RETRY as been added in OpenSSL 0.9.6.
1.0.2ze 2022-05-03
SSL_CTX_set_mode(3openssl)