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_set_get_crl,
13 X509_STORE_CTX_get_check_revocation,
14 X509_STORE_CTX_get_check_issued,
15 X509_STORE_CTX_get_get_issuer,
16 X509_STORE_CTX_get_verify_cb,
17 X509_STORE_CTX_set_verify_cb,
18 X509_STORE_CTX_verify_cb,
19 X509_STORE_CTX_print_verify_cb,
20 X509_STORE_CTX_set_current_reasons
21 - get and set X509_STORE_CTX components such as verification callback
25 #include <openssl/x509_vfy.h>
27 typedef int (*X509_STORE_CTX_verify_cb)(int, X509_STORE_CTX *);
28 int X509_STORE_CTX_print_verify_cb(int ok, X509_STORE_CTX *ctx);
30 X509_STORE_CTX_verify_cb X509_STORE_CTX_get_verify_cb(X509_STORE_CTX *ctx);
32 void X509_STORE_CTX_set_verify_cb(X509_STORE_CTX *ctx,
33 X509_STORE_CTX_verify_cb verify_cb);
35 X509_STORE_CTX_get_issuer_fn X509_STORE_CTX_get_get_issuer(X509_STORE_CTX *ctx);
36 X509_STORE_CTX_check_issued_fn X509_STORE_CTX_get_check_issued(X509_STORE_CTX *ctx);
37 X509_STORE_CTX_check_revocation_fn X509_STORE_CTX_get_check_revocation(X509_STORE_CTX *ctx);
39 X509_STORE_CTX_get_crl_fn X509_STORE_CTX_get_get_crl(X509_STORE_CTX *ctx);
41 void X509_STORE_CTX_set_get_crl(X509_STORE_CTX *ctx,
42 X509_STORE_CTX_get_crl_fn get_crl);
44 X509_STORE_CTX_check_crl_fn X509_STORE_CTX_get_check_crl(X509_STORE_CTX *ctx);
45 X509_STORE_CTX_cert_crl_fn X509_STORE_CTX_get_cert_crl(X509_STORE_CTX *ctx);
46 X509_STORE_CTX_check_policy_fn X509_STORE_CTX_get_check_policy(X509_STORE_CTX *ctx);
47 X509_STORE_CTX_lookup_certs_fn X509_STORE_CTX_get_lookup_certs(X509_STORE_CTX *ctx);
48 X509_STORE_CTX_lookup_crls_fn X509_STORE_CTX_get_lookup_crls(X509_STORE_CTX *ctx);
49 X509_STORE_CTX_cleanup_fn X509_STORE_CTX_get_cleanup(X509_STORE_CTX *ctx);
50 void X509_STORE_CTX_set_current_reasons(X509_STORE_CTX *ctx,
51 unsigned int current_reasons);
55 X509_STORE_CTX_set_verify_cb() sets the verification callback of B<ctx> to
56 B<verify_cb> overwriting any existing callback.
58 The verification callback can be used to customise the operation of certificate
59 verification, for instance by overriding error conditions or logging errors for
62 However, a verification callback is B<not> essential and the default operation
65 The B<ok> parameter to the callback indicates the value the callback should
66 return to retain the default behaviour. If it is zero then an error condition
67 is indicated. If it is 1 then no error occurred. If the flag
68 B<X509_V_FLAG_NOTIFY_POLICY> is set then B<ok> is set to 2 to indicate the
69 policy checking is complete.
71 The B<ctx> parameter to the callback is the B<X509_STORE_CTX> structure that
72 is performing the verification operation. A callback can examine this
73 structure and receive additional information about the error, for example
74 by calling X509_STORE_CTX_get_current_cert(). Additional application data can
75 be passed to the callback via the B<ex_data> mechanism.
77 X509_STORE_CTX_print_verify_cb() is a verification callback function that,
78 when a certificate verification has failed, adds an entry to the error queue
79 with code B<X509_R_CERTIFICATE_VERIFICATION_FAILED> and with diagnostic details,
80 including the most relevant fields of the target certificate that failed to
81 verify and, if appropriate, of the available untrusted and trusted certificates.
83 X509_STORE_CTX_get_verify_cb() returns the value of the current callback
84 for the specific B<ctx>.
86 X509_STORE_CTX_get_get_issuer(),
87 X509_STORE_CTX_get_check_issued(), X509_STORE_CTX_get_check_revocation(),
88 X509_STORE_CTX_get_get_crl(), X509_STORE_CTX_get_check_crl(),
89 X509_STORE_CTX_get_cert_crl(), X509_STORE_CTX_get_check_policy(),
90 X509_STORE_CTX_get_lookup_certs(), X509_STORE_CTX_get_lookup_crls()
91 and X509_STORE_CTX_get_cleanup() return the function pointers cached
92 from the corresponding B<X509_STORE>, please see
93 L<X509_STORE_set_verify(3)> for more information.
95 X509_STORE_CTX_set_get_crl() sets the function to get the crl for a given
97 When found, the crl must be assigned to I<*crl>.
98 This function must return 0 on failure and 1 on success.
99 I<If no function to get the issuer is provided, the internal default
100 function will be used instead.>
102 X509_STORE_CTX_set_current_reasons() is used in conjunction with
103 X509_STORE_CTX_get_crl_fn. The X509_STORE_CTX_get_crl_fn callback must
104 use this method to set the reason why the certificate is invalid.
109 In general a verification callback should B<NOT> unconditionally return 1 in
110 all circumstances because this will allow verification to succeed no matter
111 what the error. This effectively removes all security from the application
112 because B<any> certificate (including untrusted generated ones) will be
117 The verification callback can be set and inherited from the parent structure
118 performing the operation. In some cases (such as S/MIME verification) the
119 B<X509_STORE_CTX> structure is created and destroyed internally and the
120 only way to set a custom verification callback is by inheriting it from the
121 associated B<X509_STORE>.
125 X509_STORE_CTX_set_verify_cb() does not return a value.
129 Default callback operation:
131 int verify_callback(int ok, X509_STORE_CTX *ctx) {
135 Simple example, suppose a certificate in the chain is expired and we wish
136 to continue after this error:
138 int verify_callback(int ok, X509_STORE_CTX *ctx) {
139 /* Tolerate certificate expiration */
140 if (X509_STORE_CTX_get_error(ctx) == X509_V_ERR_CERT_HAS_EXPIRED)
142 /* Otherwise don't override */
146 More complex example, we don't wish to continue after B<any> certificate has
147 expired just one specific case:
149 int verify_callback(int ok, X509_STORE_CTX *ctx)
151 int err = X509_STORE_CTX_get_error(ctx);
152 X509 *err_cert = X509_STORE_CTX_get_current_cert(ctx);
154 if (err == X509_V_ERR_CERT_HAS_EXPIRED) {
155 if (check_is_acceptable_expired_cert(err_cert)
161 Full featured logging callback. In this case the B<bio_err> is assumed to be
162 a global logging B<BIO>, an alternative would to store a BIO in B<ctx> using
165 int verify_callback(int ok, X509_STORE_CTX *ctx)
170 err_cert = X509_STORE_CTX_get_current_cert(ctx);
171 err = X509_STORE_CTX_get_error(ctx);
172 depth = X509_STORE_CTX_get_error_depth(ctx);
174 BIO_printf(bio_err, "depth=%d ", depth);
176 X509_NAME_print_ex(bio_err, X509_get_subject_name(err_cert),
178 BIO_puts(bio_err, "\n");
181 BIO_puts(bio_err, "<no cert>\n");
183 BIO_printf(bio_err, "verify error:num=%d:%s\n", err,
184 X509_verify_cert_error_string(err));
186 case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT:
187 BIO_puts(bio_err, "issuer= ");
188 X509_NAME_print_ex(bio_err, X509_get_issuer_name(err_cert),
190 BIO_puts(bio_err, "\n");
192 case X509_V_ERR_CERT_NOT_YET_VALID:
193 case X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD:
194 BIO_printf(bio_err, "notBefore=");
195 ASN1_TIME_print(bio_err, X509_get_notBefore(err_cert));
196 BIO_printf(bio_err, "\n");
198 case X509_V_ERR_CERT_HAS_EXPIRED:
199 case X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD:
200 BIO_printf(bio_err, "notAfter=");
201 ASN1_TIME_print(bio_err, X509_get_notAfter(err_cert));
202 BIO_printf(bio_err, "\n");
204 case X509_V_ERR_NO_EXPLICIT_POLICY:
205 policies_print(bio_err, ctx);
208 if (err == X509_V_OK && ok == 2)
209 /* print out policies */
211 BIO_printf(bio_err, "verify return:%d\n", ok);
217 L<X509_STORE_CTX_get_error(3)>
218 L<X509_STORE_set_verify_cb_func(3)>
219 L<X509_STORE_CTX_get_ex_new_index(3)>
224 X509_STORE_CTX_get_get_issuer(),
225 X509_STORE_CTX_get_check_issued(), X509_STORE_CTX_get_check_revocation(),
226 X509_STORE_CTX_get_get_crl(), X509_STORE_CTX_get_check_crl(),
227 X509_STORE_CTX_get_cert_crl(), X509_STORE_CTX_get_check_policy(),
228 X509_STORE_CTX_get_lookup_certs(), X509_STORE_CTX_get_lookup_crls()
229 and X509_STORE_CTX_get_cleanup() functions were added in OpenSSL 1.1.0.
231 X509_STORE_CTX_print_verify_cb() was added in OpenSSL 3.0.
235 Copyright 2009-2023 The OpenSSL Project Authors. All Rights Reserved.
237 Licensed under the Apache License 2.0 (the "License"). You may not use
238 this file except in compliance with the License. You can obtain a copy
239 in the file LICENSE in the source distribution or at
240 L<https://www.openssl.org/source/license.html>.