SSL_CTX_SET_MSG_CALLBACK(3) | Library Functions Manual | SSL_CTX_SET_MSG_CALLBACK(3) |
SSL_CTX_set_msg_callback
,
SSL_CTX_set_msg_callback_arg
,
SSL_set_msg_callback
,
SSL_set_msg_callback_arg
—
install callback for observing protocol messages
#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);
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
NULL
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:
SSL2_VERSION
, SSL3_VERSION
and TLS1_VERSION
(for SSL 2.0, SSL 3.0 and TLS
1.0, respectively).SSL_CTX_set_msg_callback_arg
()
or
SSL_set_msg_callback_arg
().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
.
SSL_CTX_set_msg_callback
(),
SSL_CTX_set_msg_callback_arg
(),
SSL_set_msg_callback
() and
SSL_set_msg_callback_arg
() were added in OpenSSL
0.9.7.
December 1, 2016 | OpenBSD-6.1 |