SSL_CTX_load_verify_locations(3) OpenSSL SSL_CTX_load_verify_locations(3)
NAME
SSL_CTX_load_verify_locations, SSL_CTX_set_default_verify_paths,
SSL_CTX_set_default_verify_dir, SSL_CTX_set_default_verify_file - set
default locations for trusted CA certificates
SYNOPSIS
#include <openssl/ssl.h>
int SSL_CTX_load_verify_locations(SSL_CTX *ctx, const char *CAfile,
const char *CApath);
int SSL_CTX_set_default_verify_paths(SSL_CTX *ctx);
int SSL_CTX_set_default_verify_dir(SSL_CTX *ctx);
int SSL_CTX_set_default_verify_file(SSL_CTX *ctx);
DESCRIPTION
SSL_CTX_load_verify_locations() specifies the locations for ctx, at
which CA certificates for verification purposes are located. The
certificates available via CAfile and CApath are trusted.
SSL_CTX_set_default_verify_paths() specifies that the default locations
from which CA certificates are loaded should be used. There is one
default directory and one default file. The default CA certificates
directory is called "certs" in the default OpenSSL directory.
Alternatively the SSL_CERT_DIR environment variable can be defined to
override this location. The default CA certificates file is called
"cert.pem" in the default OpenSSL directory. Alternatively the
SSL_CERT_FILE environment variable can be defined to override this
location.
SSL_CTX_set_default_verify_dir() is similar to
SSL_CTX_set_default_verify_paths() except that just the default
directory is used.
SSL_CTX_set_default_verify_file() is similar to
SSL_CTX_set_default_verify_paths() except that just the default file is
used.
NOTES
If CAfile is not NULL, it points to a file of CA certificates in PEM
format. The file can contain several CA certificates identified by
-----BEGIN CERTIFICATE-----
... (CA certificate in base64 encoding) ...
-----END CERTIFICATE-----
sequences. Before, between, and after the certificates text is allowed
which can be used e.g. for descriptions of the certificates.
The CAfile is processed on execution of the
SSL_CTX_load_verify_locations() function.
If CApath is not NULL, it points to a directory containing CA
certificates in PEM format. The files each contain one CA certificate.
The files are looked up by the CA subject name hash value, which must
hence be available. If more than one CA certificate with the same name
hash value exist, the extension must be different (e.g. 9d66eef0.0,
9d66eef0.1 etc). The search is performed in the ordering of the
extension number, regardless of other properties of the certificates.
Use the c_rehash utility to create the necessary links.
The certificates in CApath are only looked up when required, e.g. when
building the certificate chain or when actually performing the
verification of a peer certificate.
When looking up CA certificates, the OpenSSL library will first search
the certificates in CAfile, then those in CApath. Certificate matching
is done based on the subject name, the key identifier (if present), and
the serial number as taken from the certificate to be verified. If
these data do not match, the next certificate will be tried. If a first
certificate matching the parameters is found, the verification process
will be performed; no other certificates for the same parameters will
be searched in case of failure.
In server mode, when requesting a client certificate, the server must
send the list of CAs of which it will accept client certificates. This
list is not influenced by the contents of CAfile or CApath and must
explicitly be set using the SSL_CTX_set_client_CA_list(3) family of
functions.
When building its own certificate chain, an OpenSSL client/server will
try to fill in missing certificates from CAfile/CApath, if the
certificate chain was not explicitly specified (see
SSL_CTX_add_extra_chain_cert(3), SSL_CTX_use_certificate(3).
WARNINGS
If several CA certificates matching the name, key identifier, and
serial number condition are available, only the first one will be
examined. This may lead to unexpected results if the same CA
certificate is available with different expiration dates. If a
"certificate expired" verification error occurs, no other certificate
will be searched. Make sure to not have expired certificates mixed with
valid ones.
RETURN VALUES
For SSL_CTX_load_verify_locations the following return values can
occur:
0 The operation failed because CAfile and CApath are NULL or the
processing at one of the locations specified failed. Check the
error stack to find out the reason.
1 The operation succeeded.
SSL_CTX_set_default_verify_paths(), SSL_CTX_set_default_verify_dir()
and SSL_CTX_set_default_verify_file() all return 1 on success or 0 on
failure. A missing default location is still treated as a success.
EXAMPLES
Generate a CA certificate file with descriptive text from the CA
certificates ca1.pem ca2.pem ca3.pem:
#!/bin/sh
rm CAfile.pem
for i in ca1.pem ca2.pem ca3.pem ; do
openssl x509 -in $i -text >> CAfile.pem
done
Prepare the directory /some/where/certs containing several CA
certificates for use as CApath:
cd /some/where/certs
c_rehash .
SEE ALSO
ssl(7), SSL_CTX_set_client_CA_list(3), SSL_get_client_CA_list(3),
SSL_CTX_use_certificate(3), SSL_CTX_add_extra_chain_cert(3),
SSL_CTX_set_cert_store(3), SSL_CTX_set_client_CA_list(3)
COPYRIGHT
Copyright 2000-2019 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
<https://www.openssl.org/source/license.html>.
1.1.1c 2019-05-28 SSL_CTX_load_verify_locations(3)
openssl 1.1.1c - Generated Mon Jun 10 07:35:47 CDT 2019