SSLv3_method(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);
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 sup-
ported 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 pro-
tocol versions, the effect is to also disable all subsequent proto-
col 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_method(), TLSv1_2_server_method(), TLSv1_2_client_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 under-
stand TLSv1.2. A server will only understand TLSv1.2 client hello
messages.
TLSv1_1_method(), TLSv1_1_server_method(), TLSv1_1_client_method()
A TLS/SSL connection established with these methods will only
understand the TLSv1.1 protocol. A client will send out TLSv1.1
client hello messages and will also indicate that it only under-
stand 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_method(), DTLSv1_2_server_method(), DTLSv1_2_client_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 set-
ting, 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
The return value points to an allocated SSL_CTX object.
SEE ALSO
SSL_CTX_set_options(3), SSL_CTX_clear_options(3), SSL_set_options(3),
SSL_CTX_free(3), SSL_accept(3), ssl(3), SSL_set_connect_state(3)
1.0.2t 2019-09-10 SSL_CTX_new(3)
Man(1) output converted with
man2html