SSL_CTX_SET_CLIENT_CA... BSD Library Functions Manual SSL_CTX_SET_CLIENT_CA...NAME
SSL_CTX_set_client_CA_list, SSL_set_client_CA_list,
SSL_CTX_add_client_CA, SSL_add_client_CA — set list of CAs sent to the
client when requesting a client certificate
SYNOPSIS
#include <openssl/ssl.h>
void
SSL_CTX_set_client_CA_list(SSL_CTX *ctx, STACK_OF(X509_NAME) *list);
void
SSL_set_client_CA_list(SSL *s, STACK_OF(X509_NAME) *list);
int
SSL_CTX_add_client_CA(SSL_CTX *ctx, X509 *cacert);
int
SSL_add_client_CA(SSL *ssl, X509 *cacert);
DESCRIPTIONSSL_CTX_set_client_CA_list() sets the list of CAs sent to the client when
requesting a client certificate for ctx.
SSL_set_client_CA_list() sets the list of CAs sent to the client when
requesting a client certificate for the chosen ssl, overriding the set‐
ting valid for ssl's SSL_CTX object.
SSL_CTX_add_client_CA() adds the CA name extracted from cacert to the
list of CAs sent to the client when requesting a client certificate for
ctx.
SSL_add_client_CA() adds the CA name extracted from cacert to the list of
CAs sent to the client when requesting a client certificate for the cho‐
sen ssl, overriding the setting valid for ssl's SSL_CTX object.
NOTES
When a TLS/SSL server requests a client certificate (see
SSL_CTX_set_verify()), it sends a list of CAs for which it will accept
certificates to the client.
This list must explicitly be set using SSL_CTX_set_client_CA_list() for
ctx and SSL_set_client_CA_list() for the specific ssl. The list speci‐
fied overrides the previous setting. The CAs listed do not become
trusted (list only contains the names, not the complete certificates);
use SSL_CTX_load_verify_locations(3) to additionally load them for veri‐
fication.
If the list of acceptable CAs is compiled in a file, the
SSL_load_client_CA_file(3) function can be used to help importing the
necessary data.
SSL_CTX_add_client_CA() and SSL_add_client_CA() can be used to add addi‐
tional items the list of client CAs. If no list was specified before
using SSL_CTX_set_client_CA_list() or SSL_set_client_CA_list(), a new
client CA list for ctx or ssl (as appropriate) is opened.
These functions are only useful for TLS/SSL servers.
RETURN VALUESSSL_CTX_set_client_CA_list() and SSL_set_client_CA_list() do not return
diagnostic information.
SSL_CTX_add_client_CA() and SSL_add_client_CA() have the following return
values:
0 A failure while manipulating the STACK_OF(X509_NAME) object
occurred or the X509_NAME could not be extracted from cacert.
Check the error stack to find out the reason.
1 The operation succeeded.
EXAMPLES
Scan all certificates in CAfile and list them as acceptable CAs:
SSL_CTX_set_client_CA_list(ctx, SSL_load_client_CA_file(CAfile));
SEE ALSOssl(3), SSL_CTX_load_verify_locations(3), SSL_get_client_CA_list(3),
SSL_load_client_CA_file(3)BSD April 26, 2024 BSD
