SSLv23_client_method(3)



SSL_CTX_new(3)               OpenSSL               SSL_CTX_new(3)

NAME

     SSL_CTX_new, SSLv23_method, SSLv23_server_method,
     SSLv23_client_method, TLSv1_2_method, TLSv1_2_server_method,
     TLSv1_2_client_method, TLSv1_1_method,
     TLSv1_1_server_method, TLSv1_1_client_method, TLSv1_method,
     TLSv1_server_method, TLSv1_client_method, SSLv3_method,
     SSLv3_server_method, SSLv3_client_method, SSLv2_method,
     SSLv2_server_method, SSLv2_client_method, DTLS_method,
     DTLS_server_method, DTLS_client_method, DTLSv1_2_method,
     DTLSv1_2_server_method, DTLSv1_2_client_method,
     DTLSv1_method, DTLSv1_server_method, DTLSv1_client_method -
     create a new SSL_CTX object as framework for TLS/SSL enabled
     functions

SYNOPSIS

      #include <openssl/ssl.h>

      SSL_CTX *SSL_CTX_new(const SSL_METHOD *method);
      const SSL_METHOD *SSLv23_method(void);
      const SSL_METHOD *SSLv23_server_method(void);
      const SSL_METHOD *SSLv23_client_method(void);
      const SSL_METHOD *TLSv1_2_method(void);
      const SSL_METHOD *TLSv1_2_server_method(void);
      const SSL_METHOD *TLSv1_2_client_method(void);
      const SSL_METHOD *TLSv1_1_method(void);
      const SSL_METHOD *TLSv1_1_server_method(void);
      const SSL_METHOD *TLSv1_1_client_method(void);
      const SSL_METHOD *TLSv1_method(void);
      const SSL_METHOD *TLSv1_server_method(void);
      const SSL_METHOD *TLSv1_client_method(void);
      #ifndef OPENSSL_NO_SSL3_METHOD
      const SSL_METHOD *SSLv3_method(void);
      const SSL_METHOD *SSLv3_server_method(void);
      const SSL_METHOD *SSLv3_client_method(void);
      #endif
      #ifndef OPENSSL_NO_SSL2
      const SSL_METHOD *SSLv2_method(void);
      const SSL_METHOD *SSLv2_server_method(void);
      const SSL_METHOD *SSLv2_client_method(void);
      #endif

      const SSL_METHOD *DTLS_method(void);
      const SSL_METHOD *DTLS_server_method(void);
      const SSL_METHOD *DTLS_client_method(void);
      const SSL_METHOD *DTLSv1_2_method(void);
      const SSL_METHOD *DTLSv1_2_server_method(void);
      const SSL_METHOD *DTLSv1_2_client_method(void);
      const SSL_METHOD *DTLSv1_method(void);
      const SSL_METHOD *DTLSv1_server_method(void);
      const SSL_METHOD *DTLSv1_client_method(void);

1.0.2t               Last change: 2019-09-10                    1

SSL_CTX_new(3)               OpenSSL               SSL_CTX_new(3)

DESCRIPTION

     SSL_CTX_new() creates a new SSL_CTX object as framework to
     establish TLS/SSL enabled connections.

NOTES

     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. method can be of
     the following types:

     SSLv23_method(), SSLv23_server_method(), SSLv23_client_method()
         These are the general-purpose version-flexible SSL/TLS
         methods.  The actual protocol version used will be
         negotiated to the highest version mutually supported by
         the client and the server.  The supported protocols are
         SSLv2, SSLv3, TLSv1, TLSv1.1 and TLSv1.2.  Most
         applications should use these method, and avoid the
         version specific methods described below.

         The list of protocols available can be further limited
         using the SSL_OP_NO_SSLv2, SSL_OP_NO_SSLv3,
         SSL_OP_NO_TLSv1, SSL_OP_NO_TLSv1_1 and SSL_OP_NO_TLSv1_2
         options of the SSL_CTX_set_options(3) or
         SSL_set_options(3) functions.  Clients should avoid
         creating "holes" in the set of protocols they support,
         when disabling a protocol, make sure that you also
         disable either all previous or all subsequent protocol
         versions.  In clients, when a protocol version is
         disabled without disabling all previous protocol
         versions, the effect is to also disable all subsequent
         protocol versions.

         The SSLv2 and SSLv3 protocols are deprecated and should
         generally not be used.  Applications should typically
         use SSL_CTX_set_options(3) in combination with the
         SSL_OP_NO_SSLv3 flag to disable negotiation of SSLv3 via
         the above version-flexible SSL/TLS methods.  The
         SSL_OP_NO_SSLv2 option is set by default, and would need
         to be cleared via SSL_CTX_clear_options(3) in order to
         enable negotiation of SSLv2.

TLSv1_2_client_method()
     TLSv1_2_method(), TLSv1_2_server_method(),
         A TLS/SSL connection established with these methods will
         only understand the TLSv1.2 protocol.  A client will
         send out TLSv1.2 client hello messages and will also
         indicate that it only understand TLSv1.2.  A server will
         only understand TLSv1.2 client hello messages.

TLSv1_1_client_method()
     TLSv1_1_method(), TLSv1_1_server_method(),
         A TLS/SSL connection established with these methods will

1.0.2t               Last change: 2019-09-10                    2

SSL_CTX_new(3)               OpenSSL               SSL_CTX_new(3)

         only understand the TLSv1.1 protocol.  A client will
         send out TLSv1.1 client hello messages and will also
         indicate that it only understand TLSv1.1.  A server will
         only understand TLSv1.1 client hello messages.

     TLSv1_method(), TLSv1_server_method(), TLSv1_client_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.

     SSLv3_method(), SSLv3_server_method(), SSLv3_client_method()
         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.  The SSLv3
         protocol is deprecated and should not be used.

     SSLv2_method(), SSLv2_server_method(), SSLv2_client_method()
         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.  The SSLv2
         protocol offers little to no security and should not be
         used.  As of OpenSSL 1.0.2g, EXPORT ciphers and 56-bit
         DES are no longer available with SSLv2.

     DTLS_method(), DTLS_server_method(), DTLS_client_method()
         These are the version-flexible DTLS methods.

DTLSv1_2_client_method()
     DTLSv1_2_method(), DTLSv1_2_server_method(),
         These are the version-specific methods for DTLSv1.2.

     DTLSv1_method(), DTLSv1_server_method(), DTLSv1_client_method()
         These are the version-specific methods for DTLSv1.

     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.

RETURN VALUES

     The following return values can occur:

     NULL
         The creation of a new SSL_CTX object failed. Check the
         error stack to find out the reason.

     Pointer to an SSL_CTX object

1.0.2t               Last change: 2019-09-10                    3

SSL_CTX_new(3)               OpenSSL               SSL_CTX_new(3)

         The return value points to an allocated SSL_CTX object.

SSLv23_client_method(3)

NAME

SYNOPSIS

DESCRIPTION

NOTES

RETURN VALUES

SEE ALSO