1X509_STORE_CTX_SET_VERIFY_CB(3ossl) OpenSSLX509_STORE_CTX_SET_VERIFY_CB(3ossl)
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6 X509_STORE_CTX_get_cleanup, X509_STORE_CTX_get_lookup_crls,
7 X509_STORE_CTX_get_lookup_certs, X509_STORE_CTX_get_check_policy,
8 X509_STORE_CTX_get_cert_crl, X509_STORE_CTX_get_check_crl,
9 X509_STORE_CTX_get_get_crl, X509_STORE_CTX_get_check_revocation,
10 X509_STORE_CTX_get_check_issued, X509_STORE_CTX_get_get_issuer,
11 X509_STORE_CTX_get_verify_cb, X509_STORE_CTX_set_verify_cb,
12 X509_STORE_CTX_verify_cb, X509_STORE_CTX_print_verify_cb - get and set
13 X509_STORE_CTX components such as verification callback
14
16 #include <openssl/x509_vfy.h>
17 typedef int (*X509_STORE_CTX_verify_cb)(int, X509_STORE_CTX *);
19 int X509_STORE_CTX_print_verify_cb(int ok, X509_STORE_CTX *ctx);
20 X509_STORE_CTX_verify_cb X509_STORE_CTX_get_verify_cb(X509_STORE_CTX *ctx);
22 void X509_STORE_CTX_set_verify_cb(X509_STORE_CTX *ctx,
24 X509_STORE_CTX_verify_cb verify_cb);
25 X509_STORE_CTX_get_issuer_fn X509_STORE_CTX_get_get_issuer(X509_STORE_CTX *ctx);
27 X509_STORE_CTX_check_issued_fn X509_STORE_CTX_get_check_issued(X509_STORE_CTX *ctx);
28 X509_STORE_CTX_check_revocation_fn X509_STORE_CTX_get_check_revocation(X509_STORE_CTX *ctx);
29 X509_STORE_CTX_get_crl_fn X509_STORE_CTX_get_get_crl(X509_STORE_CTX *ctx);
30 X509_STORE_CTX_check_crl_fn X509_STORE_CTX_get_check_crl(X509_STORE_CTX *ctx);
31 X509_STORE_CTX_cert_crl_fn X509_STORE_CTX_get_cert_crl(X509_STORE_CTX *ctx);
32 X509_STORE_CTX_check_policy_fn X509_STORE_CTX_get_check_policy(X509_STORE_CTX *ctx);
33 X509_STORE_CTX_lookup_certs_fn X509_STORE_CTX_get_lookup_certs(X509_STORE_CTX *ctx);
34 X509_STORE_CTX_lookup_crls_fn X509_STORE_CTX_get_lookup_crls(X509_STORE_CTX *ctx);
35 X509_STORE_CTX_cleanup_fn X509_STORE_CTX_get_cleanup(X509_STORE_CTX *ctx);
36
38 X509_STORE_CTX_set_verify_cb() sets the verification callback of ctx to
39 verify_cb overwriting any existing callback.
40 The verification callback can be used to customise the operation of
42 certificate verification, for instance by overriding error conditions
43 or logging errors for debugging purposes.
44 However, a verification callback is not essential and the default
46 operation is often sufficient.
47 The ok parameter to the callback indicates the value the callback
49 should return to retain the default behaviour. If it is zero then an
50 error condition is indicated. If it is 1 then no error occurred. If the
51 flag X509_V_FLAG_NOTIFY_POLICY is set then ok is set to 2 to indicate
52 the policy checking is complete.
53 The ctx parameter to the callback is the X509_STORE_CTX structure that
55 is performing the verification operation. A callback can examine this
56 structure and receive additional information about the error, for
57 example by calling X509_STORE_CTX_get_current_cert(). Additional
58 application data can be passed to the callback via the ex_data
59 mechanism.
60 X509_STORE_CTX_print_verify_cb() is a verification callback function
62 that, when a certificate verification has failed, adds an entry to the
63 error queue with code X509_R_CERTIFICATE_VERIFICATION_FAILED and with
64 diagnostic details, including the most relevant fields of the target
65 certificate that failed to verify and, if appropriate, of the available
66 untrusted and trusted certificates.
67 X509_STORE_CTX_get_verify_cb() returns the value of the current
69 callback for the specific ctx.
70 X509_STORE_CTX_get_get_issuer(), X509_STORE_CTX_get_check_issued(),
72 X509_STORE_CTX_get_check_revocation(), X509_STORE_CTX_get_get_crl(),
73 X509_STORE_CTX_get_check_crl(), X509_STORE_CTX_get_cert_crl(),
74 X509_STORE_CTX_get_check_policy(), X509_STORE_CTX_get_lookup_certs(),
75 X509_STORE_CTX_get_lookup_crls() and X509_STORE_CTX_get_cleanup()
76 return the function pointers cached from the corresponding X509_STORE,
77 please see X509_STORE_set_verify(3) for more information.
78
80 In general a verification callback should NOT unconditionally return 1
81 in all circumstances because this will allow verification to succeed no
82 matter what the error. This effectively removes all security from the
83 application because any certificate (including untrusted generated
84 ones) will be accepted.
85
87 The verification callback can be set and inherited from the parent
88 structure performing the operation. In some cases (such as S/MIME
89 verification) the X509_STORE_CTX structure is created and destroyed
90 internally and the only way to set a custom verification callback is by
91 inheriting it from the associated X509_STORE.
92
94 X509_STORE_CTX_set_verify_cb() does not return a value.
95
97 Default callback operation:
98 int verify_callback(int ok, X509_STORE_CTX *ctx) {
100 return ok;
101 }
102 Simple example, suppose a certificate in the chain is expired and we
104 wish to continue after this error:
105 int verify_callback(int ok, X509_STORE_CTX *ctx) {
107 /* Tolerate certificate expiration */
108 if (X509_STORE_CTX_get_error(ctx) == X509_V_ERR_CERT_HAS_EXPIRED)
109 return 1;
110 /* Otherwise don't override */
111 return ok;
112 }
113 More complex example, we don't wish to continue after any certificate
115 has expired just one specific case:
116 int verify_callback(int ok, X509_STORE_CTX *ctx)
118 {
119 int err = X509_STORE_CTX_get_error(ctx);
120 X509 *err_cert = X509_STORE_CTX_get_current_cert(ctx);
121 if (err == X509_V_ERR_CERT_HAS_EXPIRED) {
123 if (check_is_acceptable_expired_cert(err_cert)
124 return 1;
125 }
126 return ok;
127 }
128 Full featured logging callback. In this case the bio_err is assumed to
130 be a global logging BIO, an alternative would to store a BIO in ctx
131 using ex_data.
132 int verify_callback(int ok, X509_STORE_CTX *ctx)
134 {
135 X509 *err_cert;
136 int err, depth;
137 err_cert = X509_STORE_CTX_get_current_cert(ctx);
139 err = X509_STORE_CTX_get_error(ctx);
140 depth = X509_STORE_CTX_get_error_depth(ctx);
141 BIO_printf(bio_err, "depth=%d ", depth);
143 if (err_cert) {
144 X509_NAME_print_ex(bio_err, X509_get_subject_name(err_cert),
145 0, XN_FLAG_ONELINE);
146 BIO_puts(bio_err, "\n");
147 }
148 else
149 BIO_puts(bio_err, "<no cert>\n");
150 if (!ok)
151 BIO_printf(bio_err, "verify error:num=%d:%s\n", err,
152 X509_verify_cert_error_string(err));
153 switch (err) {
154 case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT:
155 BIO_puts(bio_err, "issuer= ");
156 X509_NAME_print_ex(bio_err, X509_get_issuer_name(err_cert),
157 0, XN_FLAG_ONELINE);
158 BIO_puts(bio_err, "\n");
159 break;
160 case X509_V_ERR_CERT_NOT_YET_VALID:
161 case X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD:
162 BIO_printf(bio_err, "notBefore=");
163 ASN1_TIME_print(bio_err, X509_get_notBefore(err_cert));
164 BIO_printf(bio_err, "\n");
165 break;
166 case X509_V_ERR_CERT_HAS_EXPIRED:
167 case X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD:
168 BIO_printf(bio_err, "notAfter=");
169 ASN1_TIME_print(bio_err, X509_get_notAfter(err_cert));
170 BIO_printf(bio_err, "\n");
171 break;
172 case X509_V_ERR_NO_EXPLICIT_POLICY:
173 policies_print(bio_err, ctx);
174 break;
175 }
176 if (err == X509_V_OK && ok == 2)
177 /* print out policies */
178 BIO_printf(bio_err, "verify return:%d\n", ok);
180 return(ok);
181 }
182
184 X509_STORE_CTX_get_error(3) X509_STORE_set_verify_cb_func(3)
185 X509_STORE_CTX_get_ex_new_index(3)
186
188 The X509_STORE_CTX_get_get_issuer(), X509_STORE_CTX_get_check_issued(),
189 X509_STORE_CTX_get_check_revocation(), X509_STORE_CTX_get_get_crl(),
190 X509_STORE_CTX_get_check_crl(), X509_STORE_CTX_get_cert_crl(),
191 X509_STORE_CTX_get_check_policy(), X509_STORE_CTX_get_lookup_certs(),
192 X509_STORE_CTX_get_lookup_crls() and X509_STORE_CTX_get_cleanup()
193 functions were added in OpenSSL 1.1.0.
194 X509_STORE_CTX_print_verify_cb() was added in OpenSSL 3.0.
196
198 Copyright 2009-2020 The OpenSSL Project Authors. All Rights Reserved.
199 Licensed under the Apache License 2.0 (the "License"). You may not use
201 this file except in compliance with the License. You can obtain a copy
202 in the file LICENSE in the source distribution or at
203 <https://www.openssl.org/source/license.html>.
2043.1.1 2023-08-31X509_STORE_CTX_SET_VERIFY_CB(3ossl)