Automatically generated by Pod::Man 4.14 (Pod::Simple 3.40)

Standard preamble:
========================================================================
..

..

.. Set up some character translations and predefined strings. \*(-- will
give an unbreakable dash, \*(PI will give pi, \*(L" will give a left
double quote, and \*(R" will give a right double quote. \*(C+ will
give a nicer C++. Capital omega is used to do unbreakable dashes and
therefore won't be available. \*(C` and \*(C' expand to `' in nroff,
nothing in troff, for use with C<>.
.tr \(*W- . ds -- \(*W- . ds PI pi . if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch . if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo 12 pitch . ds L" "" . ds R" "" . ds C` "" . ds C' "" 'br\} . ds -- \|\(em\| . ds PI \(*p . ds L" `` . ds R" '' . ds C` . ds C' 'br\}
Escape single quotes in literal strings from groff's Unicode transform.

If the F register is >0, we'll generate index entries on stderr for
titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index
entries marked with X<> in POD. Of course, you'll have to process the
output yourself in some meaningful fashion.

Avoid warning from groff about undefined register 'F'.
.. .nr rF 0 . if \nF \{\ . de IX . tm Index:\\$1\t\\n%\t"\\$2" .. . if !\nF==2 \{\ . nr % 0 . nr F 2 . \} . \} .\} .rr rF
Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2).
Fear. Run. Save yourself. No user-serviceable parts.
. \" fudge factors for nroff and troff . ds #H 0 . ds #V .8m . ds #F .3m . ds #[ \f1 . ds #] .\} . ds #H ((1u-(\\\\n(.fu%2u))*.13m) . ds #V .6m . ds #F 0 . ds #[ \& . ds #] \& .\} . \" simple accents for nroff and troff . ds ' \& . ds ` \& . ds ^ \& . ds , \& . ds ~ ~ . ds / .\} . ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u" . ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u' . ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u' . ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u' . ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u' . ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u' .\} . \" troff and (daisy-wheel) nroff accents . \" corrections for vroff . \" for low resolution devices (crt and lpr) \{\ . ds : e . ds 8 ss . ds o a . ds d- d\h'-1'\(ga . ds D- D\h'-1'\(hy . ds th \o'bp' . ds Th \o'LP' . ds ae ae . ds Ae AE .\} ========================================================================

Title "SSL_CTX_NEW 3" For nroff, turn off justification. Always turn off hyphenation; it makes
way too many mistakes in technical documents.
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 Header "SYNOPSIS" .Vb 1 #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 .Ve Header "DESCRIPTION" \fBSSL_CTX_new() creates a new \s-1SSL_CTX\s0 object as framework to establish \s-1TLS/SSL\s0 or \s-1DTLS\s0 enabled connections. An \s-1SSL_CTX\s0 object is reference counted. Creating an \s-1SSL_CTX\s0 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 \fB\s-1SSL_CTX\s0 object are freed. SSL_CTX_up_ref() increments the reference count for an existing \s-1SSL_CTX\s0 structure. Header "NOTES" The \s-1SSL_CTX\s0 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. \fBmethod can be of the following types: Item "TLS_method(), TLS_server_method(), TLS_client_method()" These are the general-purpose version-flexible \s-1SSL/TLS\s0 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, which are deprecated. Item "SSLv23_method(), SSLv23_server_method(), SSLv23_client_method()" These functions do not exist anymore, they have been renamed to \fBTLS_method(), TLS_server_method() and TLS_client_method() respectively. Currently, the old function calls are renamed to the corresponding new ones by preprocessor macros, to ensure that existing code which uses the old function names still compiles. However, using the old function names is deprecated and new code should call the new functions instead. Item "TLSv1_2_method(), TLSv1_2_server_method(), TLSv1_2_client_method()" A \s-1TLS/SSL\s0 connection established with these methods will only understand the TLSv1.2 protocol. These methods are deprecated. Item "TLSv1_1_method(), TLSv1_1_server_method(), TLSv1_1_client_method()" A \s-1TLS/SSL\s0 connection established with these methods will only understand the TLSv1.1 protocol. These methods are deprecated. Item "TLSv1_method(), TLSv1_server_method(), TLSv1_client_method()" A \s-1TLS/SSL\s0 connection established with these methods will only understand the TLSv1 protocol. These methods are deprecated. Item "SSLv3_method(), SSLv3_server_method(), SSLv3_client_method()" A \s-1TLS/SSL\s0 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 \s-1DTLS\s0 methods. Currently supported protocols are \s-1DTLS 1.0\s0 and \s-1DTLS 1.2.\s0 Item "DTLSv1_2_method(), DTLSv1_2_server_method(), DTLSv1_2_client_method()" These are the version-specific methods for DTLSv1.2. These methods are deprecated. Item "DTLSv1_method(), DTLSv1_server_method(), DTLSv1_client_method()" These are the version-specific methods for DTLSv1. These methods are deprecated.

\fBSSL_CTX_new() initializes the list of ciphers, the session cache setting, the callbacks, the keys and certificates and the options to their default values.

\fBTLS_method(), TLS_server_method(), TLS_client_method(), DTLS_method(), \fBDTLS_server_method() and DTLS_client_method() are the version-flexible methods. All other methods only support one specific protocol version. Use the 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 SSL_CTX_set_min_proto_version\|(3), \fBSSL_set_min_proto_version\|(3), SSL_CTX_set_max_proto_version\|(3) and \fBSSL_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 \s-1TLS 1.0, TLS 1.1, TLS 1.2\s0 or \s-1TLS 1.3.\s0

The list of protocols available can also be limited using the \fBSSL_OP_NO_SSLv3, SSL_OP_NO_TLSv1, SSL_OP_NO_TLSv1_1, \fBSSL_OP_NO_TLSv1_3, SSL_OP_NO_TLSv1_2 and SSL_OP_NO_TLSv1_3 options of the \fBSSL_CTX_set_options\|(3) or SSL_set_options\|(3) functions, but this approach is not recommended. Clients should avoid creating \*(L"holes\*(R" 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 SSLv3 protocol is deprecated and should generally not be used. Applications should typically use SSL_CTX_set_min_proto_version\|(3) to set the minimum protocol to at least \s-1TLS1_VERSION\s0.

Header "RETURN VALUES" The following return values can occur: Item "NULL" The creation of a new \s-1SSL_CTX\s0 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 \s-1SSL_CTX\s0 object. .Sp \fBSSL_CTX_up_ref() returns 1 for success and 0 for failure. Header "SEE ALSO" \fBSSL_CTX_set_options\|(3), SSL_CTX_free\|(3), SSL_accept\|(3), \fBSSL_CTX_set_min_proto_version\|(3), ssl\|(7), SSL_set_connect_state\|(3) Header "HISTORY" Support for SSLv2 and the corresponding SSLv2_method(), \fBSSLv2_server_method() and SSLv2_client_method() functions where removed in OpenSSL 1.1.0.

\fBSSLv23_method(), SSLv23_server_method() and SSLv23_client_method() were deprecated and the preferred TLS_method(), TLS_server_method() and TLS_client_method() functions were added in OpenSSL 1.1.0.

All version-specific methods were deprecated in OpenSSL 1.1.0.

Header "COPYRIGHT" Copyright 2000-2019 The OpenSSL Project Authors. All Rights Reserved.

Licensed under the OpenSSL license (the \*(L"License\*(R"). You may not use this file except in compliance with the License. You can obtain a copy in the file \s-1LICENSE\s0 in the source distribution or at <https://www.openssl.org/source/license.html>.