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 - get and set verification callback
20 #include <openssl/x509_vfy.h>
22 typedef int (*X509_STORE_CTX_verify_cb)(int, X509_STORE_CTX *);
24 X509_STORE_CTX_verify_cb X509_STORE_CTX_get_verify_cb(X509_STORE_CTX *ctx);
26 void X509_STORE_CTX_set_verify_cb(X509_STORE_CTX *ctx,
27 X509_STORE_CTX_verify_cb verify_cb);
29 X509_STORE_CTX_get_issuer_fn X509_STORE_CTX_get_get_issuer(X509_STORE_CTX *ctx);
30 X509_STORE_CTX_check_issued_fn X509_STORE_CTX_get_check_issued(X509_STORE_CTX *ctx);
31 X509_STORE_CTX_check_revocation_fn X509_STORE_CTX_get_check_revocation(X509_STORE_CTX *ctx);
32 X509_STORE_CTX_get_crl_fn X509_STORE_CTX_get_get_crl(X509_STORE_CTX *ctx);
33 X509_STORE_CTX_check_crl_fn X509_STORE_CTX_get_check_crl(X509_STORE_CTX *ctx);
34 X509_STORE_CTX_cert_crl_fn X509_STORE_CTX_get_cert_crl(X509_STORE_CTX *ctx);
35 X509_STORE_CTX_check_policy_fn X509_STORE_CTX_get_check_policy(X509_STORE_CTX *ctx);
36 X509_STORE_CTX_lookup_certs_fn X509_STORE_CTX_get_lookup_certs(X509_STORE_CTX *ctx);
37 X509_STORE_CTX_lookup_crls_fn X509_STORE_CTX_get_lookup_crls(X509_STORE_CTX *ctx);
38 X509_STORE_CTX_cleanup_fn X509_STORE_CTX_get_cleanup(X509_STORE_CTX *ctx);
42 X509_STORE_CTX_set_verify_cb() sets the verification callback of B<ctx> to
43 B<verify_cb> overwriting any existing callback.
45 The verification callback can be used to customise the operation of certificate
46 verification, either by overriding error conditions or logging errors for
49 However a verification callback is B<not> essential and the default operation
52 The B<ok> parameter to the callback indicates the value the callback should
53 return to retain the default behaviour. If it is zero then an error condition
54 is indicated. If it is 1 then no error occurred. If the flag
55 B<X509_V_FLAG_NOTIFY_POLICY> is set then B<ok> is set to 2 to indicate the
56 policy checking is complete.
58 The B<ctx> parameter to the callback is the B<X509_STORE_CTX> structure that
59 is performing the verification operation. A callback can examine this
60 structure and receive additional information about the error, for example
61 by calling X509_STORE_CTX_get_current_cert(). Additional application data can
62 be passed to the callback via the B<ex_data> mechanism.
64 X509_STORE_CTX_get_verify_cb() returns the value of the current callback
65 for the specific B<ctx>.
67 X509_STORE_CTX_get_get_issuer(),
68 X509_STORE_CTX_get_check_issued(), X509_STORE_CTX_get_check_revocation(),
69 X509_STORE_CTX_get_get_crl(), X509_STORE_CTX_get_check_crl(),
70 X509_STORE_CTX_get_cert_crl(), X509_STORE_CTX_get_check_policy(),
71 X509_STORE_CTX_get_lookup_certs(), X509_STORE_CTX_get_lookup_crls()
72 and X509_STORE_CTX_get_cleanup() return the function pointers cached
73 from the corresponding B<X509_STORE>, please see
74 L<X509_STORE_set_verify(3)> for more information.
79 In general a verification callback should B<NOT> unconditionally return 1 in
80 all circumstances because this will allow verification to succeed no matter
81 what the error. This effectively removes all security from the application
82 because B<any> certificate (including untrusted generated ones) will be
87 The verification callback can be set and inherited from the parent structure
88 performing the operation. In some cases (such as S/MIME verification) the
89 B<X509_STORE_CTX> structure is created and destroyed internally and the
90 only way to set a custom verification callback is by inheriting it from the
91 associated B<X509_STORE>.
95 X509_STORE_CTX_set_verify_cb() does not return a value.
99 Default callback operation:
101 int verify_callback(int ok, X509_STORE_CTX *ctx)
106 Simple example, suppose a certificate in the chain is expired and we wish
107 to continue after this error:
109 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);
125 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);
149 X509_NAME_print_ex(bio_err, X509_get_subject_name(err_cert),
151 BIO_puts(bio_err, "\n");
154 BIO_puts(bio_err, "<no cert>\n");
156 BIO_printf(bio_err, "verify error:num=%d:%s\n", err,
157 X509_verify_cert_error_string(err));
160 case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT:
161 BIO_puts(bio_err, "issuer= ");
162 X509_NAME_print_ex(bio_err, X509_get_issuer_name(err_cert),
164 BIO_puts(bio_err, "\n");
166 case X509_V_ERR_CERT_NOT_YET_VALID:
167 case X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD:
168 BIO_printf(bio_err, "notBefore=");
169 ASN1_TIME_print(bio_err, X509_get_notBefore(err_cert));
170 BIO_printf(bio_err, "\n");
172 case X509_V_ERR_CERT_HAS_EXPIRED:
173 case X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD:
174 BIO_printf(bio_err, "notAfter=");
175 ASN1_TIME_print(bio_err, X509_get_notAfter(err_cert));
176 BIO_printf(bio_err, "\n");
178 case X509_V_ERR_NO_EXPLICIT_POLICY:
179 policies_print(bio_err, ctx);
182 if (err == X509_V_OK && ok == 2)
183 /* print out policies */
185 BIO_printf(bio_err, "verify return:%d\n", ok);
191 L<X509_STORE_CTX_get_error(3)>
192 L<X509_STORE_set_verify_cb_func(3)>
193 L<X509_STORE_CTX_get_ex_new_index(3)>
197 X509_STORE_CTX_get_get_issuer(),
198 X509_STORE_CTX_get_check_issued(), X509_STORE_CTX_get_check_revocation(),
199 X509_STORE_CTX_get_get_crl(), X509_STORE_CTX_get_check_crl(),
200 X509_STORE_CTX_get_cert_crl(), X509_STORE_CTX_get_check_policy(),
201 X509_STORE_CTX_get_lookup_certs(), X509_STORE_CTX_get_lookup_crls()
202 and X509_STORE_CTX_get_cleanup() were added in OpenSSL 1.1.0.
206 Copyright 2009-2016 The OpenSSL Project Authors. All Rights Reserved.
208 Licensed under the OpenSSL license (the "License"). You may not use
209 this file except in compliance with the License. You can obtain a copy
210 in the file LICENSE in the source distribution or at
211 L<https://www.openssl.org/source/license.html>.