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Diffstat (limited to 'doc/man3/SSL_CTX_new.pod')
-rw-r--r-- | doc/man3/SSL_CTX_new.pod | 219 |
1 files changed, 219 insertions, 0 deletions
diff --git a/doc/man3/SSL_CTX_new.pod b/doc/man3/SSL_CTX_new.pod new file mode 100644 index 000000000000..d07834151eb7 --- /dev/null +++ b/doc/man3/SSL_CTX_new.pod @@ -0,0 +1,219 @@ +=pod + +=head1 NAME + +TLSv1_2_method, TLSv1_2_server_method, TLSv1_2_client_method, +SSL_CTX_new, SSL_CTX_up_ref, SSLv3_method, SSLv3_server_method, +SSLv3_client_method, TLSv1_method, TLSv1_server_method, TLSv1_client_method, +TLSv1_1_method, TLSv1_1_server_method, TLSv1_1_client_method, TLS_method, +TLS_server_method, TLS_client_method, SSLv23_method, SSLv23_server_method, +SSLv23_client_method, DTLS_method, DTLS_server_method, DTLS_client_method, +DTLSv1_method, DTLSv1_server_method, DTLSv1_client_method, +DTLSv1_2_method, DTLSv1_2_server_method, DTLSv1_2_client_method +- create a new SSL_CTX object as framework for TLS/SSL or DTLS enabled +functions + +=head1 SYNOPSIS + + #include <openssl/ssl.h> + + SSL_CTX *SSL_CTX_new(const SSL_METHOD *method); + int SSL_CTX_up_ref(SSL_CTX *ctx); + + const SSL_METHOD *TLS_method(void); + const SSL_METHOD *TLS_server_method(void); + const SSL_METHOD *TLS_client_method(void); + + const SSL_METHOD *SSLv23_method(void); + const SSL_METHOD *SSLv23_server_method(void); + const SSL_METHOD *SSLv23_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_TLS1_METHOD + const SSL_METHOD *TLSv1_method(void); + const SSL_METHOD *TLSv1_server_method(void); + const SSL_METHOD *TLSv1_client_method(void); + #endif + + #ifndef OPENSSL_NO_TLS1_1_METHOD + const SSL_METHOD *TLSv1_1_method(void); + const SSL_METHOD *TLSv1_1_server_method(void); + const SSL_METHOD *TLSv1_1_client_method(void); + #endif + + #ifndef OPENSSL_NO_TLS1_2_METHOD + const SSL_METHOD *TLSv1_2_method(void); + const SSL_METHOD *TLSv1_2_server_method(void); + const SSL_METHOD *TLSv1_2_client_method(void); + #endif + + const SSL_METHOD *DTLS_method(void); + const SSL_METHOD *DTLS_server_method(void); + const SSL_METHOD *DTLS_client_method(void); + + #ifndef OPENSSL_NO_DTLS1_METHOD + const SSL_METHOD *DTLSv1_method(void); + const SSL_METHOD *DTLSv1_server_method(void); + const SSL_METHOD *DTLSv1_client_method(void); + #endif + + #ifndef OPENSSL_NO_DTLS1_2_METHOD + const SSL_METHOD *DTLSv1_2_method(void); + const SSL_METHOD *DTLSv1_2_server_method(void); + const SSL_METHOD *DTLSv1_2_client_method(void); + #endif + +=head1 DESCRIPTION + +SSL_CTX_new() creates a new B<SSL_CTX> object as framework to +establish TLS/SSL or DTLS enabled connections. An B<SSL_CTX> object is +reference counted. Creating an B<SSL_CTX> object for the first time increments +the reference count. Freeing it (using SSL_CTX_free) decrements it. When the +reference count drops to zero, any memory or resources allocated to the +B<SSL_CTX> object are freed. SSL_CTX_up_ref() increments the reference count for +an existing B<SSL_CTX> structure. + +=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 TLS_method(), TLS_server_method(), TLS_client_method() + +These are the general-purpose I<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 SSLv3, TLSv1, TLSv1.1, TLSv1.2 and TLSv1.3. +Applications should use these methods, and avoid the version-specific +methods described below. + +=item SSLv23_method(), SSLv23_server_method(), SSLv23_client_method() + +Use of these functions is deprecated. They have been replaced with the above +TLS_method(), TLS_server_method() and TLS_client_method() respectively. New +code should use those functions instead. + +=item 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. + +=item 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. + +=item TLSv1_method(), TLSv1_server_method(), TLSv1_client_method() + +A TLS/SSL connection established with these methods will only understand the +TLSv1 protocol. + +=item SSLv3_method(), SSLv3_server_method(), SSLv3_client_method() + +A TLS/SSL connection established with these methods will only understand the +SSLv3 protocol. +The SSLv3 protocol is deprecated and should not be used. + +=item DTLS_method(), DTLS_server_method(), DTLS_client_method() + +These are the version-flexible DTLS methods. +Currently supported protocols are DTLS 1.0 and DTLS 1.2. + +=item DTLSv1_2_method(), DTLSv1_2_server_method(), DTLSv1_2_client_method() + +These are the version-specific methods for DTLSv1.2. + +=item DTLSv1_method(), DTLSv1_server_method(), DTLSv1_client_method() + +These are the version-specific methods for DTLSv1. + +=back + +SSL_CTX_new() initializes the list of ciphers, the session cache setting, the +callbacks, the keys and certificates and the options to their default values. + +TLS_method(), TLS_server_method(), TLS_client_method(), DTLS_method(), +DTLS_server_method() and DTLS_client_method() are the I<version-flexible> +methods. +All other methods only support one specific protocol version. +Use the I<version-flexible> methods instead of the version specific methods. + +If you want to limit the supported protocols for the version flexible +methods you can use L<SSL_CTX_set_min_proto_version(3)>, +L<SSL_set_min_proto_version(3)>, L<SSL_CTX_set_max_proto_version(3)> and +L<SSL_set_max_proto_version(3)> functions. +Using these functions it is possible to choose e.g. TLS_server_method() +and be able to negotiate with all possible clients, but to only +allow newer protocols like TLS 1.0, TLS 1.1, TLS 1.2 or TLS 1.3. + +The list of protocols available can also be limited using the +B<SSL_OP_NO_SSLv3>, B<SSL_OP_NO_TLSv1>, B<SSL_OP_NO_TLSv1_1>, +B<SSL_OP_NO_TLSv1_3>, B<SSL_OP_NO_TLSv1_2> and B<SSL_OP_NO_TLSv1_3> +options of the +L<SSL_CTX_set_options(3)> or L<SSL_set_options(3)> functions, but this approach +is not recommended. 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 I<all> +previous protocol versions, the effect is to also disable all subsequent +protocol versions. + +The SSLv3 protocol is deprecated and should generally not be used. +Applications should typically use L<SSL_CTX_set_min_proto_version(3)> to set +the minimum protocol to at least B<TLS1_VERSION>. + +=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. + +SSL_CTX_up_ref() returns 1 for success and 0 for failure. + +=back + +=head1 HISTORY + +Support for SSLv2 and the corresponding SSLv2_method(), +SSLv2_server_method() and SSLv2_client_method() functions where +removed in OpenSSL 1.1.0. + +SSLv23_method(), SSLv23_server_method() and SSLv23_client_method() +were deprecated and the preferred TLS_method(), TLS_server_method() +and TLS_client_method() functions were introduced in OpenSSL 1.1.0. + +All version-specific methods were deprecated in OpenSSL 1.1.0. + +=head1 SEE ALSO + +L<SSL_CTX_set_options(3)>, L<SSL_CTX_free(3)>, L<SSL_accept(3)>, +L<SSL_CTX_set_min_proto_version(3)>, L<ssl(7)>, L<SSL_set_connect_state(3)> + +=head1 COPYRIGHT + +Copyright 2000-2018 The OpenSSL Project Authors. All Rights Reserved. + +Licensed under the OpenSSL license (the "License"). You may not use +this file except in compliance with the License. You can obtain a copy +in the file LICENSE in the source distribution or at +L<https://www.openssl.org/source/license.html>. + +=cut |