5 X509_STORE_CTX_get_cleanup,
6 X509_STORE_CTX_get_lookup_crls,
7 X509_STORE_CTX_get_lookup_certs,
8 X509_STORE_CTX_get_check_policy,
9 X509_STORE_CTX_get_cert_crl,
10 X509_STORE_CTX_get_check_crl,
11 X509_STORE_CTX_get_get_crl,
12 X509_STORE_CTX_get_check_revocation,
13 X509_STORE_CTX_get_check_issued,
14 X509_STORE_CTX_get_get_issuer,
15 X509_STORE_CTX_get_verify_cb,
16 X509_STORE_CTX_set_verify_cb,
17 X509_STORE_CTX_verify_cb
18 - get and set verification callback
22 #include <openssl/x509_vfy.h>
24 typedef int (*X509_STORE_CTX_verify_cb)(int, X509_STORE_CTX *);
26 X509_STORE_CTX_verify_cb X509_STORE_CTX_get_verify_cb(X509_STORE_CTX *ctx);
28 void X509_STORE_CTX_set_verify_cb(X509_STORE_CTX *ctx,
29 X509_STORE_CTX_verify_cb verify_cb);
31 X509_STORE_CTX_get_issuer_fn X509_STORE_CTX_get_get_issuer(X509_STORE_CTX *ctx);
32 X509_STORE_CTX_check_issued_fn X509_STORE_CTX_get_check_issued(X509_STORE_CTX *ctx);
33 X509_STORE_CTX_check_revocation_fn X509_STORE_CTX_get_check_revocation(X509_STORE_CTX *ctx);
34 X509_STORE_CTX_get_crl_fn X509_STORE_CTX_get_get_crl(X509_STORE_CTX *ctx);
35 X509_STORE_CTX_check_crl_fn X509_STORE_CTX_get_check_crl(X509_STORE_CTX *ctx);
36 X509_STORE_CTX_cert_crl_fn X509_STORE_CTX_get_cert_crl(X509_STORE_CTX *ctx);
37 X509_STORE_CTX_check_policy_fn X509_STORE_CTX_get_check_policy(X509_STORE_CTX *ctx);
38 X509_STORE_CTX_lookup_certs_fn X509_STORE_CTX_get_lookup_certs(X509_STORE_CTX *ctx);
39 X509_STORE_CTX_lookup_crls_fn X509_STORE_CTX_get_lookup_crls(X509_STORE_CTX *ctx);
40 X509_STORE_CTX_cleanup_fn X509_STORE_CTX_get_cleanup(X509_STORE_CTX *ctx);
44 X509_STORE_CTX_set_verify_cb() sets the verification callback of B<ctx> to
45 B<verify_cb> overwriting any existing callback.
47 The verification callback can be used to customise the operation of certificate
48 verification, either by overriding error conditions or logging errors for
51 However, a verification callback is B<not> essential and the default operation
54 The B<ok> parameter to the callback indicates the value the callback should
55 return to retain the default behaviour. If it is zero then an error condition
56 is indicated. If it is 1 then no error occurred. If the flag
57 B<X509_V_FLAG_NOTIFY_POLICY> is set then B<ok> is set to 2 to indicate the
58 policy checking is complete.
60 The B<ctx> parameter to the callback is the B<X509_STORE_CTX> structure that
61 is performing the verification operation. A callback can examine this
62 structure and receive additional information about the error, for example
63 by calling X509_STORE_CTX_get_current_cert(). Additional application data can
64 be passed to the callback via the B<ex_data> mechanism.
66 X509_STORE_CTX_get_verify_cb() returns the value of the current callback
67 for the specific B<ctx>.
69 X509_STORE_CTX_get_get_issuer(),
70 X509_STORE_CTX_get_check_issued(), X509_STORE_CTX_get_check_revocation(),
71 X509_STORE_CTX_get_get_crl(), X509_STORE_CTX_get_check_crl(),
72 X509_STORE_CTX_get_cert_crl(), X509_STORE_CTX_get_check_policy(),
73 X509_STORE_CTX_get_lookup_certs(), X509_STORE_CTX_get_lookup_crls()
74 and X509_STORE_CTX_get_cleanup() return the function pointers cached
75 from the corresponding B<X509_STORE>, please see
76 L<X509_STORE_set_verify(3)> for more information.
81 In general a verification callback should B<NOT> unconditionally return 1 in
82 all circumstances because this will allow verification to succeed no matter
83 what the error. This effectively removes all security from the application
84 because B<any> certificate (including untrusted generated ones) will be
89 The verification callback can be set and inherited from the parent structure
90 performing the operation. In some cases (such as S/MIME verification) the
91 B<X509_STORE_CTX> structure is created and destroyed internally and the
92 only way to set a custom verification callback is by inheriting it from the
93 associated B<X509_STORE>.
97 X509_STORE_CTX_set_verify_cb() does not return a value.
101 Default callback operation:
103 int verify_callback(int ok, X509_STORE_CTX *ctx) {
107 Simple example, suppose a certificate in the chain is expired and we wish
108 to continue after this error:
110 int verify_callback(int ok, X509_STORE_CTX *ctx) {
111 /* Tolerate certificate expiration */
112 if (X509_STORE_CTX_get_error(ctx) == X509_V_ERR_CERT_HAS_EXPIRED)
114 /* Otherwise don't override */
118 More complex example, we don't wish to continue after B<any> certificate has
119 expired just one specific case:
121 int verify_callback(int ok, X509_STORE_CTX *ctx)
123 int err = X509_STORE_CTX_get_error(ctx);
124 X509 *err_cert = X509_STORE_CTX_get_current_cert(ctx);
126 if (err == X509_V_ERR_CERT_HAS_EXPIRED) {
127 if (check_is_acceptable_expired_cert(err_cert)
133 Full featured logging callback. In this case the B<bio_err> is assumed to be
134 a global logging B<BIO>, an alternative would to store a BIO in B<ctx> using
137 int verify_callback(int ok, X509_STORE_CTX *ctx)
142 err_cert = X509_STORE_CTX_get_current_cert(ctx);
143 err = X509_STORE_CTX_get_error(ctx);
144 depth = X509_STORE_CTX_get_error_depth(ctx);
146 BIO_printf(bio_err, "depth=%d ", depth);
148 X509_NAME_print_ex(bio_err, X509_get_subject_name(err_cert),
150 BIO_puts(bio_err, "\n");
153 BIO_puts(bio_err, "<no cert>\n");
155 BIO_printf(bio_err, "verify error:num=%d:%s\n", err,
156 X509_verify_cert_error_string(err));
158 case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT:
159 BIO_puts(bio_err, "issuer= ");
160 X509_NAME_print_ex(bio_err, X509_get_issuer_name(err_cert),
162 BIO_puts(bio_err, "\n");
164 case X509_V_ERR_CERT_NOT_YET_VALID:
165 case X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD:
166 BIO_printf(bio_err, "notBefore=");
167 ASN1_TIME_print(bio_err, X509_get_notBefore(err_cert));
168 BIO_printf(bio_err, "\n");
170 case X509_V_ERR_CERT_HAS_EXPIRED:
171 case X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD:
172 BIO_printf(bio_err, "notAfter=");
173 ASN1_TIME_print(bio_err, X509_get_notAfter(err_cert));
174 BIO_printf(bio_err, "\n");
176 case X509_V_ERR_NO_EXPLICIT_POLICY:
177 policies_print(bio_err, ctx);
180 if (err == X509_V_OK && ok == 2)
181 /* print out policies */
183 BIO_printf(bio_err, "verify return:%d\n", ok);
189 L<X509_STORE_CTX_get_error(3)>
190 L<X509_STORE_set_verify_cb_func(3)>
191 L<X509_STORE_CTX_get_ex_new_index(3)>
196 X509_STORE_CTX_get_get_issuer(),
197 X509_STORE_CTX_get_check_issued(), X509_STORE_CTX_get_check_revocation(),
198 X509_STORE_CTX_get_get_crl(), X509_STORE_CTX_get_check_crl(),
199 X509_STORE_CTX_get_cert_crl(), X509_STORE_CTX_get_check_policy(),
200 X509_STORE_CTX_get_lookup_certs(), X509_STORE_CTX_get_lookup_crls()
201 and X509_STORE_CTX_get_cleanup() functions were added in OpenSSL 1.1.0.
205 Copyright 2009-2020 The OpenSSL Project Authors. All Rights Reserved.
207 Licensed under the OpenSSL license (the "License"). You may not use
208 this file except in compliance with the License. You can obtain a copy
209 in the file LICENSE in the source distribution or at
210 L<https://www.openssl.org/source/license.html>.