SSL_CTX_new - Create a new SSL_CTX object as framework for
TLS/SSL enabled functions
#include <openssl/ssl.h>
SSL_CTX *SSL_CTX_new(
SSL_METHOD *method );
The SSL_CTX_new() function creates a new SSL_CTX object as
framework to establish TLS/SSL enabled connections.
The SSL_CTX object uses method as connection method. The
methods exist in a generic type (for client and server
use), a server only type, and a client only type. The
method can be of the following types: A TLS/SSL connection
established with these methods will only understand the
SSLv2 protocol. A client will send out SSLv2 client hello
messages and will also indicate that it only understand
SSLv2. A server will only understand SSLv2 client hello
messages. A TLS/SSL connection established with these
methods will only understand the SSLv3 protocol. A client
will send out SSLv3 client hello messages and will indicate
that it only understands SSLv3. A server will only
understand SSLv3 client hello messages. This especially
means, that it will not understand SSLv2 client hello messages
which are widely used for compatibility reasons. See
SSLv23_*_method(). A TLS/SSL connection established with
these methods will only understand the TLSv1 protocol. A
client will send out TLSv1 client hello messages and will
indicate that it only understands TLSv1. A server will
only understand TLSv1 client hello messages. This especially
means, that it will not understand SSLv2 client
hello messages which are widely used for compatibility
reasons, see SSLv23_*_method(). It will also not understand
SSLv3 client hello messages. A TLS/SSL connection
established with these methods will understand the SSLv2,
SSLv3, and TLSv1 protocol. A client will send out SSLv2
client hello messages and will indicate that it also
understands SSLv3 and TLSv1. A server will understand
SSLv2, SSLv3, and TLSv1 client hello messages. This is
the best choice when compatibility is a concern.
The list of protocols available can later be limited using
the SSL_OP_NO_SSLv2, SSL_OP_NO_SSLv3, SSL_OP_NO_TLSv1
options of the SSL_CTX_set_options() or SSL_set_options()
functions. Using these options, it is possible to choose
the SSLv23_server_method() function, for example, and be
able to negotiate with all possible clients, but to only
allow newer protocols like SSLv3 or TLSv1.
The SSL_CTX_new() function initializes the list of
ciphers, the session cache setting, the callbacks, the
keys and certificates, and the options to its default values.
The following return values can occur: The creation of a
new SSL_CTX object failed. Check the error stack to
determine the reason. The return value points to an allocated
SSL_CTX object.
Functions: SSL_CTX_free(3), SSL_accept(3), ssl(3),
SSL_set_connect_state(3)
SSL_CTX_new(3)
[ Back ] |