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Diffstat (limited to 'openssl/doc/ssl/SSL_CTX_new.pod')
-rw-r--r-- | openssl/doc/ssl/SSL_CTX_new.pod | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/openssl/doc/ssl/SSL_CTX_new.pod b/openssl/doc/ssl/SSL_CTX_new.pod new file mode 100644 index 000000000..465220a75 --- /dev/null +++ b/openssl/doc/ssl/SSL_CTX_new.pod @@ -0,0 +1,94 @@ +=pod + +=head1 NAME + +SSL_CTX_new - create a new SSL_CTX object as framework for TLS/SSL enabled functions + +=head1 SYNOPSIS + + #include <openssl/ssl.h> + + SSL_CTX *SSL_CTX_new(SSL_METHOD *method); + +=head1 DESCRIPTION + +SSL_CTX_new() creates a new B<SSL_CTX> object as framework to establish +TLS/SSL enabled connections. + +=head1 NOTES + +The SSL_CTX object uses B<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. B<method> can be of the following types: + +=over 4 + +=item SSLv2_method(void), SSLv2_server_method(void), SSLv2_client_method(void) + +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. + +=item SSLv3_method(void), SSLv3_server_method(void), SSLv3_client_method(void) + +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(). + +=item TLSv1_method(void), TLSv1_server_method(void), TLSv1_client_method(void) + +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. + +=item SSLv23_method(void), SSLv23_server_method(void), SSLv23_client_method(void) + +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. + +=back + +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 B<SSL_CTX_set_options()> or +B<SSL_set_options()> functions. Using these options it is possible to choose +e.g. SSLv23_server_method() and be able to negotiate with all possible +clients, but to only allow newer protocols like SSLv3 or TLSv1. + +SSL_CTX_new() initializes the list of ciphers, the session cache setting, +the callbacks, the keys and certificates, and the options to its default +values. + +=head1 RETURN VALUES + +The following return values can occur: + +=over 4 + +=item NULL + +The creation of a new SSL_CTX object failed. Check the error stack to +find out the reason. + +=item Pointer to an SSL_CTX object + +The return value points to an allocated SSL_CTX object. + +=back + +=head1 SEE ALSO + +L<SSL_CTX_free(3)|SSL_CTX_free(3)>, L<SSL_accept(3)|SSL_accept(3)>, +L<ssl(3)|ssl(3)>, L<SSL_set_connect_state(3)|SSL_set_connect_state(3)> + +=cut |