1SSL_CTX_LOAD_VERIFY_LOCATIONS(3)    OpenSSL   SSL_CTX_LOAD_VERIFY_LOCATIONS(3)
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NAME

6       SSL_CTX_load_verify_locations, SSL_CTX_set_default_verify_paths,
7       SSL_CTX_set_default_verify_dir, SSL_CTX_set_default_verify_file - set
8       default locations for trusted CA certificates
9

SYNOPSIS

11        #include <openssl/ssl.h>
12
13        int SSL_CTX_load_verify_locations(SSL_CTX *ctx, const char *CAfile,
14                                          const char *CApath);
15
16        int SSL_CTX_set_default_verify_paths(SSL_CTX *ctx);
17
18        int SSL_CTX_set_default_verify_dir(SSL_CTX *ctx);
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20        int SSL_CTX_set_default_verify_file(SSL_CTX *ctx);
21

DESCRIPTION

23       SSL_CTX_load_verify_locations() specifies the locations for ctx, at
24       which CA certificates for verification purposes are located. The
25       certificates available via CAfile and CApath are trusted.
26
27       SSL_CTX_set_default_verify_paths() specifies that the default locations
28       from which CA certificates are loaded should be used. There is one
29       default directory and one default file. The default CA certificates
30       directory is called "certs" in the default OpenSSL directory.
31       Alternatively the SSL_CERT_DIR environment variable can be defined to
32       override this location. The default CA certificates file is called
33       "cert.pem" in the default OpenSSL directory. Alternatively the
34       SSL_CERT_FILE environment variable can be defined to override this
35       location.
36
37       SSL_CTX_set_default_verify_dir() is similar to
38       SSL_CTX_set_default_verify_paths() except that just the default
39       directory is used.
40
41       SSL_CTX_set_default_verify_file() is similar to
42       SSL_CTX_set_default_verify_paths() except that just the default file is
43       used.
44

NOTES

46       If CAfile is not NULL, it points to a file of CA certificates in PEM
47       format. The file can contain several CA certificates identified by
48
49        -----BEGIN CERTIFICATE-----
50        ... (CA certificate in base64 encoding) ...
51        -----END CERTIFICATE-----
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53       sequences. Before, between, and after the certificates text is allowed
54       which can be used e.g. for descriptions of the certificates.
55
56       The CAfile is processed on execution of the
57       SSL_CTX_load_verify_locations() function.
58
59       If CApath is not NULL, it points to a directory containing CA
60       certificates in PEM format. The files each contain one CA certificate.
61       The files are looked up by the CA subject name hash value, which must
62       hence be available.  If more than one CA certificate with the same name
63       hash value exist, the extension must be different (e.g. 9d66eef0.0,
64       9d66eef0.1 etc). The search is performed in the ordering of the
65       extension number, regardless of other properties of the certificates.
66       Use the c_rehash utility to create the necessary links.
67
68       The certificates in CApath are only looked up when required, e.g. when
69       building the certificate chain or when actually performing the
70       verification of a peer certificate.
71
72       When looking up CA certificates, the OpenSSL library will first search
73       the certificates in CAfile, then those in CApath. Certificate matching
74       is done based on the subject name, the key identifier (if present), and
75       the serial number as taken from the certificate to be verified. If
76       these data do not match, the next certificate will be tried. If a first
77       certificate matching the parameters is found, the verification process
78       will be performed; no other certificates for the same parameters will
79       be searched in case of failure.
80
81       In server mode, when requesting a client certificate, the server must
82       send the list of CAs of which it will accept client certificates. This
83       list is not influenced by the contents of CAfile or CApath and must
84       explicitly be set using the SSL_CTX_set_client_CA_list(3) family of
85       functions.
86
87       When building its own certificate chain, an OpenSSL client/server will
88       try to fill in missing certificates from CAfile/CApath, if the
89       certificate chain was not explicitly specified (see
90       SSL_CTX_add_extra_chain_cert(3), SSL_CTX_use_certificate(3).
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WARNINGS

93       If several CA certificates matching the name, key identifier, and
94       serial number condition are available, only the first one will be
95       examined. This may lead to unexpected results if the same CA
96       certificate is available with different expiration dates. If a
97       "certificate expired" verification error occurs, no other certificate
98       will be searched. Make sure to not have expired certificates mixed with
99       valid ones.
100

RETURN VALUES

102       For SSL_CTX_load_verify_locations the following return values can
103       occur:
104
105       0   The operation failed because CAfile and CApath are NULL or the
106           processing at one of the locations specified failed. Check the
107           error stack to find out the reason.
108
109       1   The operation succeeded.
110
111       SSL_CTX_set_default_verify_paths(), SSL_CTX_set_default_verify_dir()
112       and SSL_CTX_set_default_verify_file() all return 1 on success or 0 on
113       failure. A missing default location is still treated as a success.
114

EXAMPLES

116       Generate a CA certificate file with descriptive text from the CA
117       certificates ca1.pem ca2.pem ca3.pem:
118
119        #!/bin/sh
120        rm CAfile.pem
121        for i in ca1.pem ca2.pem ca3.pem ; do
122            openssl x509 -in $i -text >> CAfile.pem
123        done
124
125       Prepare the directory /some/where/certs containing several CA
126       certificates for use as CApath:
127
128        cd /some/where/certs
129        c_rehash .
130

SEE ALSO

132       ssl(7), SSL_CTX_set_client_CA_list(3), SSL_get_client_CA_list(3),
133       SSL_CTX_use_certificate(3), SSL_CTX_add_extra_chain_cert(3),
134       SSL_CTX_set_cert_store(3), SSL_CTX_set_client_CA_list(3)
135
137       Copyright 2000-2019 The OpenSSL Project Authors. All Rights Reserved.
138
139       Licensed under the OpenSSL license (the "License").  You may not use
140       this file except in compliance with the License.  You can obtain a copy
141       in the file LICENSE in the source distribution or at
142       <https://www.openssl.org/source/license.html>.
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1461.1.1l                            2021-09-15  SSL_CTX_LOAD_VERIFY_LOCATIONS(3)
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