=pod

=head1 NAME

SSL_set0_CA_list, SSL_CTX_set0_CA_list, SSL_get0_CA_list,
SSL_CTX_get0_CA_list, SSL_add1_to_CA_list, SSL_CTX_add1_to_CA_list,
SSL_get0_peer_CA_list - get or set CA list

=head1 SYNOPSIS

 #include <openssl/ssl.h>

 void SSL_CTX_set0_CA_list(SSL_CTX *ctx, STACK_OF(X509_NAME) *name_list);
 void SSL_set0_CA_list(SSL *s, STACK_OF(X509_NAME) *name_list);
 const STACK_OF(X509_NAME) *SSL_CTX_get0_CA_list(const SSL_CTX *ctx);
 const STACK_OF(X509_NAME) *SSL_get0_CA_list(const SSL *s);
 int SSL_CTX_add1_to_CA_list(SSL_CTX *ctx, const X509 *x);
 int SSL_add1_to_CA_list(SSL *ssl, const X509 *x);

 const STACK_OF(X509_NAME) *SSL_get0_peer_CA_list(const SSL *s);

=head1 DESCRIPTION

SSL_CTX_set0_CA_list() sets the list of CAs to be sent to the peer to
B<name_list>. Ownership of B<name_list> is transferred to B<ctx> and
it should not be freed by the caller.

SSL_set0_CA_list() sets the list of CAs to be sent to the peer to B<name_list>
overriding any list set in the parent B<SSL_CTX> of B<s>. Ownership of
B<name_list> is transferred to B<s> and it should not be freed by the caller.

SSL_CTX_get0_CA_list() retrieves any previously set list of CAs set for
B<ctx>.

SSL_CTX_get0_CA_list() retrieves any previously set list of CAs set for
B<s> or if none are set the list from the parent B<SSL_CTX> is retrieved.

SSL_CTX_add1_to_CA_list() appends the CA subject name extracted from B<x> to the
list of CAs sent to peer for B<ctx>.

SSL_add1_to_CA_list() appends the CA subject name extracted from B<x> to the
list of CAs sent to the peer for B<s>, overriding the setting in the parent
B<SSL_CTX>.

SSL_get0_peer_CA_list() retrieves the list of CA names (if any) the peer
has sent.

=head1 NOTES

These functions are generalised versions of the client authentication
CA list functions such as L<SSL_CTX_set_client_CA_list(3)>.

For TLS versions before 1.3 the list of CA names is only sent from the server
to client when requesting a client certificate. So any list of CA names set
is never sent from client to server and the list of CA names retrieved by
SSL_get0_peer_CA_list() is always B<NULL>.

For TLS 1.3 the list of CA names is sent using the B<certificate_authorities>
extension and will be sent by a client (in the ClientHello message) or by
a server (when requesting a certificate).

=head1 RETURN VALUES

SSL_CTX_set0_CA_list() and SSL_set0_CA_list() do not return a value.

SSL_CTX_get0_CA_list() and SSL_get0_CA_list() return a stack of CA names
or B<NULL> is no CA names are set.

SSL_CTX_add1_to_CA_list() and SSL_add1_to_CA_list() return 1 for success and 0
for failure.

SSL_get0_peer_CA_list() returns a stack of CA names sent by the peer or
B<NULL> or an empty stack if no list was sent.

=head1 SEE ALSO

L<ssl(7)>,
L<SSL_CTX_set_client_CA_list(3)>,
L<SSL_get_client_CA_list(3)>,
L<SSL_load_client_CA_file(3)>,
L<SSL_CTX_load_verify_locations(3)>

=head1 COPYRIGHT

Copyright 2017 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>.

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