from small one page howto to huge articles all in one place
 

search text in:





Poll
Which kernel version do you use?





poll results

Last additions:
using iotop to find disk usage hogs

using iotop to find disk usage hogs

words:

887

views:

106573

userrating:

average rating: 1.7 (85 votes) (1=very good 6=terrible)


May 25th. 2007:
Words

486

Views

220809

why adblockers are bad


Workaround and fixes for the current Core Dump Handling vulnerability affected kernels

Workaround and fixes for the current Core Dump Handling vulnerability affected kernels

words:

161

views:

101197

userrating:

average rating: 1.3 (28 votes) (1=very good 6=terrible)


April, 26th. 2006:

Druckversion
You are here: manpages





SSL_CTX_set_msg_callback

Section: OpenSSL (3)
Updated: 2017-05-25
Index Return to Main Contents
 

NAME

SSL_CTX_set_msg_callback, SSL_CTX_set_msg_callback_arg, SSL_set_msg_callback, SSL_get_msg_callback_arg - install callback for observing protocol messages  

SYNOPSIS

 #include <openssl/ssl.h>

 void SSL_CTX_set_msg_callback(SSL_CTX *ctx, void (*cb)(int write_p, int version, int content_type, const void *buf, size_t len, SSL *ssl, void *arg));
 void SSL_CTX_set_msg_callback_arg(SSL_CTX *ctx, void *arg);

 void SSL_set_msg_callback(SSL *ssl, void (*cb)(int write_p, int version, int content_type, const void *buf, size_t len, SSL *ssl, void *arg));
 void SSL_set_msg_callback_arg(SSL *ssl, void *arg);

 

DESCRIPTION

SSL_CTX_set_msg_callback() or SSL_set_msg_callback() can be used to define a message callback function cb for observing all SSL/TLS protocol messages (such as handshake messages) that are received or sent. SSL_CTX_set_msg_callback_arg() and SSL_set_msg_callback_arg() can be used to set argument arg to the callback function, which is available for arbitrary application use.

SSL_CTX_set_msg_callback() and SSL_CTX_set_msg_callback_arg() specify default settings that will be copied to new SSL objects by SSL_new(3). SSL_set_msg_callback() and SSL_set_msg_callback_arg() modify the actual settings of an SSL object. Using a 0 pointer for cb disables the message callback.

When cb is called by the SSL/TLS library for a protocol message, the function arguments have the following meaning:

write_p
This flag is 0 when a protocol message has been received and 1 when a protocol message has been sent.
version
The protocol version according to which the protocol message is interpreted by the library. Currently, this is one of SSL2_VERSION, SSL3_VERSION and TLS1_VERSION (for SSL 2.0, SSL 3.0 and TLS 1.0, respectively).
content_type
In the case of SSL 2.0, this is always 0. In the case of SSL 3.0 or TLS 1.0, this is one of the ContentType values defined in the protocol specification (change_cipher_spec(20), alert(21), handshake(22); but never application_data(23) because the callback will only be called for protocol messages).
buf, len
buf points to a buffer containing the protocol message, which consists of len bytes. The buffer is no longer valid after the callback function has returned.
ssl
The SSL object that received or sent the message.
arg
The user-defined argument optionally defined by SSL_CTX_set_msg_callback_arg() or SSL_set_msg_callback_arg().
 

NOTES

Protocol messages are passed to the callback function after decryption and fragment collection where applicable. (Thus record boundaries are not visible.)

If processing a received protocol message results in an error, the callback function may not be called. For example, the callback function will never see messages that are considered too large to be processed.

Due to automatic protocol version negotiation, version is not necessarily the protocol version used by the sender of the message: If a TLS 1.0 ClientHello message is received by an SSL 3.0-only server, version will be SSL3_VERSION.  

SEE ALSO

ssl(3), SSL_new(3)  

HISTORY

SSL_CTX_set_msg_callback(), SSL_CTX_set_msg_callback_arg(), SSL_set_msg_callback() and SSL_get_msg_callback_arg() were added in OpenSSL 0.9.7.


 

Index

NAME
SYNOPSIS
DESCRIPTION
NOTES
SEE ALSO
HISTORY


Please read "Why adblockers are bad".



Other free services
toURL.org
Shorten long
URLs to short
links like
http://tourl.org/2
tourl.org
.
Reverse DNS lookup
Find out which hostname(s)
resolve to a
given IP or other hostnames for the server
www.reversednslookup.org
rdf newsfeed | rss newsfeed | Atom newsfeed
- Powered by LeopardCMS - Running on Gentoo -
Copyright 2004-2017 Sascha Nitsch Unternehmensberatung UG(haftungsbeschränkt)
Valid XHTML1.1 : Valid CSS : buttonmaker
- Level Triple-A Conformance to Web Content Accessibility Guidelines 1.0 -
- Copyright and legal notices -
Time to create this page: 2.8 ms