1X509_VERIFY_PARAM_SET_FLAGS(3ossl)  OpenSSL X509_VERIFY_PARAM_SET_FLAGS(3ossl)
2
3
4

NAME

6       X509_VERIFY_PARAM_set_flags, X509_VERIFY_PARAM_clear_flags,
7       X509_VERIFY_PARAM_get_flags, X509_VERIFY_PARAM_set_purpose,
8       X509_VERIFY_PARAM_get_inh_flags, X509_VERIFY_PARAM_set_inh_flags,
9       X509_VERIFY_PARAM_set_trust, X509_VERIFY_PARAM_set_depth,
10       X509_VERIFY_PARAM_get_depth, X509_VERIFY_PARAM_set_auth_level,
11       X509_VERIFY_PARAM_get_auth_level, X509_VERIFY_PARAM_set_time,
12       X509_VERIFY_PARAM_get_time, X509_VERIFY_PARAM_add0_policy,
13       X509_VERIFY_PARAM_set1_policies, X509_VERIFY_PARAM_get0_host,
14       X509_VERIFY_PARAM_set1_host, X509_VERIFY_PARAM_add1_host,
15       X509_VERIFY_PARAM_set_hostflags, X509_VERIFY_PARAM_get_hostflags,
16       X509_VERIFY_PARAM_get0_peername, X509_VERIFY_PARAM_get0_email,
17       X509_VERIFY_PARAM_set1_email, X509_VERIFY_PARAM_set1_ip,
18       X509_VERIFY_PARAM_get1_ip_asc, X509_VERIFY_PARAM_set1_ip_asc - X509
19       verification parameters
20

SYNOPSIS

22        #include <openssl/x509_vfy.h>
23
24        int X509_VERIFY_PARAM_set_flags(X509_VERIFY_PARAM *param,
25                                        unsigned long flags);
26        int X509_VERIFY_PARAM_clear_flags(X509_VERIFY_PARAM *param,
27                                          unsigned long flags);
28        unsigned long X509_VERIFY_PARAM_get_flags(const X509_VERIFY_PARAM *param);
29
30        int X509_VERIFY_PARAM_set_inh_flags(X509_VERIFY_PARAM *param,
31                                            uint32_t flags);
32        uint32_t X509_VERIFY_PARAM_get_inh_flags(const X509_VERIFY_PARAM *param);
33
34        int X509_VERIFY_PARAM_set_purpose(X509_VERIFY_PARAM *param, int purpose);
35        int X509_VERIFY_PARAM_set_trust(X509_VERIFY_PARAM *param, int trust);
36
37        void X509_VERIFY_PARAM_set_time(X509_VERIFY_PARAM *param, time_t t);
38        time_t X509_VERIFY_PARAM_get_time(const X509_VERIFY_PARAM *param);
39
40        int X509_VERIFY_PARAM_add0_policy(X509_VERIFY_PARAM *param,
41                                          ASN1_OBJECT *policy);
42        int X509_VERIFY_PARAM_set1_policies(X509_VERIFY_PARAM *param,
43                                            STACK_OF(ASN1_OBJECT) *policies);
44
45        void X509_VERIFY_PARAM_set_depth(X509_VERIFY_PARAM *param, int depth);
46        int X509_VERIFY_PARAM_get_depth(const X509_VERIFY_PARAM *param);
47
48        void X509_VERIFY_PARAM_set_auth_level(X509_VERIFY_PARAM *param,
49                                              int auth_level);
50        int X509_VERIFY_PARAM_get_auth_level(const X509_VERIFY_PARAM *param);
51
52        char *X509_VERIFY_PARAM_get0_host(X509_VERIFY_PARAM *param, int n);
53        int X509_VERIFY_PARAM_set1_host(X509_VERIFY_PARAM *param,
54                                        const char *name, size_t namelen);
55        int X509_VERIFY_PARAM_add1_host(X509_VERIFY_PARAM *param,
56                                        const char *name, size_t namelen);
57        void X509_VERIFY_PARAM_set_hostflags(X509_VERIFY_PARAM *param,
58                                             unsigned int flags);
59        unsigned int X509_VERIFY_PARAM_get_hostflags(const X509_VERIFY_PARAM *param);
60        char *X509_VERIFY_PARAM_get0_peername(const X509_VERIFY_PARAM *param);
61        char *X509_VERIFY_PARAM_get0_email(X509_VERIFY_PARAM *param);
62        int X509_VERIFY_PARAM_set1_email(X509_VERIFY_PARAM *param,
63                                         const char *email, size_t emaillen);
64        char *X509_VERIFY_PARAM_get1_ip_asc(X509_VERIFY_PARAM *param);
65        int X509_VERIFY_PARAM_set1_ip(X509_VERIFY_PARAM *param,
66                                      const unsigned char *ip, size_t iplen);
67        int X509_VERIFY_PARAM_set1_ip_asc(X509_VERIFY_PARAM *param, const char *ipasc);
68

DESCRIPTION

70       These functions manipulate the X509_VERIFY_PARAM structure associated
71       with a certificate verification operation.
72
73       The X509_VERIFY_PARAM_set_flags() function sets the flags in param by
74       oring it with flags. See "VERIFICATION FLAGS" for a complete
75       description of values the flags parameter can take.
76
77       X509_VERIFY_PARAM_get_flags() returns the flags in param.
78
79       X509_VERIFY_PARAM_get_inh_flags() returns the inheritance flags in
80       param which specifies how verification flags are copied from one
81       structure to another. X509_VERIFY_PARAM_set_inh_flags() sets the
82       inheritance flags.  See the INHERITANCE FLAGS section for a description
83       of these bits.
84
85       X509_VERIFY_PARAM_clear_flags() clears the flags flags in param.
86
87       X509_VERIFY_PARAM_set_purpose() sets the verification purpose in param
88       to purpose. This determines the acceptable purpose of the certificate
89       chain, for example X509_PURPOSE_SSL_CLIENT.  The purpose requirement is
90       cleared if purpose is 0.
91
92       X509_VERIFY_PARAM_set_trust() sets the trust setting in param to trust.
93
94       X509_VERIFY_PARAM_set_time() sets the verification time in param to t.
95       Normally the current time is used.
96
97       X509_VERIFY_PARAM_add0_policy() adds policy to the acceptable policy
98       set.  Contrary to preexisting documentation of this function it does
99       not enable policy checking.
100
101       X509_VERIFY_PARAM_set1_policies() enables policy checking (it is
102       disabled by default) and sets the acceptable policy set to policies.
103       Any existing policy set is cleared. The policies parameter can be NULL
104       to clear an existing policy set.
105
106       X509_VERIFY_PARAM_set_depth() sets the maximum verification depth to
107       depth.  That is the maximum number of intermediate CA certificates that
108       can appear in a chain.  A maximal depth chain contains 2 more
109       certificates than the limit, since neither the end-entity certificate
110       nor the trust-anchor count against this limit.  Thus a depth limit of 0
111       only allows the end-entity certificate to be signed directly by the
112       trust anchor, while with a depth limit of 1 there can be one
113       intermediate CA certificate between the trust anchor and the end-entity
114       certificate.
115
116       X509_VERIFY_PARAM_set_auth_level() sets the authentication security
117       level to auth_level.  The authentication security level determines the
118       acceptable signature and public key strength when verifying certificate
119       chains.  For a certificate chain to validate, the public keys of all
120       the certificates must meet the specified security level.  The signature
121       algorithm security level is not enforced for the chain's trust anchor
122       certificate, which is either directly trusted or validated by means
123       other than its signature.  See SSL_CTX_set_security_level(3) for the
124       definitions of the available levels.  The default security level is -1,
125       or "not set".  At security level 0 or lower all algorithms are
126       acceptable.  Security level 1 requires at least 80-bit-equivalent
127       security and is broadly interoperable, though it will, for example,
128       reject MD5 signatures or RSA keys shorter than 1024 bits.
129
130       X509_VERIFY_PARAM_get0_host() returns the nth expected DNS hostname
131       that has been set using X509_VERIFY_PARAM_set1_host() or
132       X509_VERIFY_PARAM_add1_host().  To obtain all names start with n = 0
133       and increment n as long as no NULL pointer is returned.
134
135       X509_VERIFY_PARAM_set1_host() sets the expected DNS hostname to name
136       clearing any previously specified hostname.  If name is NULL, or empty
137       the list of hostnames is cleared, and name checks are not performed on
138       the peer certificate.  If name is NUL-terminated, namelen may be zero,
139       otherwise namelen must be set to the length of name.
140
141       When a hostname is specified, certificate verification automatically
142       invokes X509_check_host(3) with flags equal to the flags argument given
143       to X509_VERIFY_PARAM_set_hostflags() (default zero).  Applications are
144       strongly advised to use this interface in preference to explicitly
145       calling X509_check_host(3), hostname checks may be out of scope with
146       the DANE-EE(3) certificate usage, and the internal check will be
147       suppressed as appropriate when DANE verification is enabled.
148
149       When the subject CommonName will not be ignored, whether as a result of
150       the X509_CHECK_FLAG_ALWAYS_CHECK_SUBJECT host flag, or because no DNS
151       subject alternative names are present in the certificate, any DNS name
152       constraints in issuer certificates apply to the subject CommonName as
153       well as the subject alternative name extension.
154
155       When the subject CommonName will be ignored, whether as a result of the
156       X509_CHECK_FLAG_NEVER_CHECK_SUBJECT host flag, or because some DNS
157       subject alternative names are present in the certificate, DNS name
158       constraints in issuer certificates will not be applied to the subject
159       DN.  As described in X509_check_host(3) the
160       X509_CHECK_FLAG_NEVER_CHECK_SUBJECT flag takes precedence over the
161       X509_CHECK_FLAG_ALWAYS_CHECK_SUBJECT flag.
162
163       X509_VERIFY_PARAM_get_hostflags() returns any host flags previously set
164       via a call to X509_VERIFY_PARAM_set_hostflags().
165
166       X509_VERIFY_PARAM_add1_host() adds name as an additional reference
167       identifier that can match the peer's certificate.  Any previous names
168       set via X509_VERIFY_PARAM_set1_host() or X509_VERIFY_PARAM_add1_host()
169       are retained, no change is made if name is NULL or empty.  When
170       multiple names are configured, the peer is considered verified when any
171       name matches.
172
173       X509_VERIFY_PARAM_get0_peername() returns the DNS hostname or subject
174       CommonName from the peer certificate that matched one of the reference
175       identifiers.  When wildcard matching is not disabled, or when a
176       reference identifier specifies a parent domain (starts with ".")
177       rather than a hostname, the peer name may be a wildcard name or a sub-
178       domain of the reference identifier respectively.  The return string is
179       allocated by the library and is no longer valid once the associated
180       param argument is freed.  Applications must not free the return value.
181
182       X509_VERIFY_PARAM_get0_email() returns the expected RFC822 email
183       address.
184
185       X509_VERIFY_PARAM_set1_email() sets the expected RFC822 email address
186       to email.  If email is NUL-terminated, emaillen may be zero, otherwise
187       emaillen must be set to the length of email.  When an email address is
188       specified, certificate verification automatically invokes
189       X509_check_email(3).
190
191       X509_VERIFY_PARAM_get1_ip_asc() returns the expected IP address as a
192       string.  The caller is responsible for freeing it.
193
194       X509_VERIFY_PARAM_set1_ip() sets the expected IP address to ip.  The ip
195       argument is in binary format, in network byte-order and iplen must be
196       set to 4 for IPv4 and 16 for IPv6.  When an IP address is specified,
197       certificate verification automatically invokes X509_check_ip(3).
198
199       X509_VERIFY_PARAM_set1_ip_asc() sets the expected IP address to ipasc.
200       The ipasc argument is a NUL-terminal ASCII string: dotted decimal quad
201       for IPv4 and colon-separated hexadecimal for IPv6.  The condensed "::"
202       notation is supported for IPv6 addresses.
203

RETURN VALUES

205       X509_VERIFY_PARAM_set_flags(), X509_VERIFY_PARAM_clear_flags(),
206       X509_VERIFY_PARAM_set_inh_flags(), X509_VERIFY_PARAM_set_purpose(),
207       X509_VERIFY_PARAM_set_trust(), X509_VERIFY_PARAM_add0_policy()
208       X509_VERIFY_PARAM_set1_policies(), X509_VERIFY_PARAM_set1_host(),
209       X509_VERIFY_PARAM_add1_host(), X509_VERIFY_PARAM_set1_email(),
210       X509_VERIFY_PARAM_set1_ip() and X509_VERIFY_PARAM_set1_ip_asc() return
211       1 for success and 0 for failure.
212
213       X509_VERIFY_PARAM_get0_host(), X509_VERIFY_PARAM_get0_email(), and
214       X509_VERIFY_PARAM_get1_ip_asc(), return the string pointers pecified
215       above or NULL if the respective value has not been set or on error.
216
217       X509_VERIFY_PARAM_get_flags() returns the current verification flags.
218
219       X509_VERIFY_PARAM_get_hostflags() returns any current host flags.
220
221       X509_VERIFY_PARAM_get_inh_flags() returns the current inheritance
222       flags.
223
224       X509_VERIFY_PARAM_set_time() and X509_VERIFY_PARAM_set_depth() do not
225       return values.
226
227       X509_VERIFY_PARAM_get_depth() returns the current verification depth.
228
229       X509_VERIFY_PARAM_get_auth_level() returns the current authentication
230       security level.
231

VERIFICATION FLAGS

233       The verification flags consists of zero or more of the following flags
234       ored together.
235
236       X509_V_FLAG_CRL_CHECK enables CRL checking for the certificate chain
237       leaf certificate. An error occurs if a suitable CRL cannot be found.
238
239       X509_V_FLAG_CRL_CHECK_ALL enables CRL checking for the entire
240       certificate chain.
241
242       X509_V_FLAG_IGNORE_CRITICAL disables critical extension checking. By
243       default any unhandled critical extensions in certificates or (if
244       checked) CRLs result in a fatal error. If this flag is set unhandled
245       critical extensions are ignored. WARNING setting this option for
246       anything other than debugging purposes can be a security risk. Finer
247       control over which extensions are supported can be performed in the
248       verification callback.
249
250       The X509_V_FLAG_X509_STRICT flag disables workarounds for some broken
251       certificates and makes the verification strictly apply X509 rules.
252
253       X509_V_FLAG_ALLOW_PROXY_CERTS enables proxy certificate verification.
254
255       X509_V_FLAG_POLICY_CHECK enables certificate policy checking, by
256       default no policy checking is performed. Additional information is sent
257       to the verification callback relating to policy checking.
258
259       X509_V_FLAG_EXPLICIT_POLICY, X509_V_FLAG_INHIBIT_ANY and
260       X509_V_FLAG_INHIBIT_MAP set the require explicit policy, inhibit any
261       policy and inhibit policy mapping flags respectively as defined in
262       RFC3280. Policy checking is automatically enabled if any of these flags
263       are set.
264
265       If X509_V_FLAG_NOTIFY_POLICY is set and the policy checking is
266       successful a special status code is set to the verification callback.
267       This permits it to examine the valid policy tree and perform additional
268       checks or simply log it for debugging purposes.
269
270       By default some additional features such as indirect CRLs and CRLs
271       signed by different keys are disabled. If
272       X509_V_FLAG_EXTENDED_CRL_SUPPORT is set they are enabled.
273
274       If X509_V_FLAG_USE_DELTAS is set delta CRLs (if present) are used to
275       determine certificate status. If not set deltas are ignored.
276
277       X509_V_FLAG_CHECK_SS_SIGNATURE requests checking the signature of the
278       last certificate in a chain if the certificate is supposedly self-
279       signed.  This is prohibited and will result in an error if it is a non-
280       conforming CA certificate with key usage restrictions not including the
281       keyCertSign bit.  By default this check is disabled because it doesn't
282       add any additional security but in some cases applications might want
283       to check the signature anyway. A side effect of not checking the self-
284       signature of such a certificate is that disabled or unsupported message
285       digests used for the signature are not treated as fatal errors.
286
287       When X509_V_FLAG_TRUSTED_FIRST is set, which is always the case since
288       OpenSSL 1.1.0, construction of the certificate chain in
289       X509_verify_cert(3) searches the trust store for issuer certificates
290       before searching the provided untrusted certificates.  Local issuer
291       certificates are often more likely to satisfy local security
292       requirements and lead to a locally trusted root.  This is especially
293       important when some certificates in the trust store have explicit trust
294       settings (see "TRUST SETTINGS" in openssl-x509(1)).
295
296       The X509_V_FLAG_NO_ALT_CHAINS flag could have been used before OpenSSL
297       1.1.0 to suppress checking for alternative chains.  By default, unless
298       X509_V_FLAG_TRUSTED_FIRST is set, when building a certificate chain, if
299       the first certificate chain found is not trusted, then OpenSSL will
300       attempt to replace untrusted certificates supplied by the peer with
301       certificates from the trust store to see if an alternative chain can be
302       found that is trusted.  As of OpenSSL 1.1.0, with
303       X509_V_FLAG_TRUSTED_FIRST always set, this option has no effect.
304
305       The X509_V_FLAG_PARTIAL_CHAIN flag causes non-self-signed certificates
306       in the trust store to be treated as trust anchors, in the same way as
307       self-signed root CA certificates.  This makes it possible to trust
308       self-issued certificates as well as certificates issued by an
309       intermediate CA without having to trust their ancestor root CA.  With
310       OpenSSL 1.1.0 and later and X509_V_FLAG_PARTIAL_CHAIN set, chain
311       construction stops as soon as the first certificate contained in the
312       trust store is added to the chain, whether that certificate is a self-
313       signed "root" certificate or a not self-signed "intermediate" or self-
314       issued certificate.  Thus, when an intermediate certificate is found in
315       the trust store, the verified chain passed to callbacks may be shorter
316       than it otherwise would be without the X509_V_FLAG_PARTIAL_CHAIN flag.
317
318       The X509_V_FLAG_NO_CHECK_TIME flag suppresses checking the validity
319       period of certificates and CRLs against the current time. If
320       X509_VERIFY_PARAM_set_time() is used to specify a verification time,
321       the check is not suppressed.
322

INHERITANCE FLAGS

324       These flags specify how parameters are "inherited" from one structure
325       to another.
326
327       If X509_VP_FLAG_ONCE is set then the current setting is zeroed after
328       the next call.
329
330       If X509_VP_FLAG_LOCKED is set then no values are copied.  This
331       overrides all of the following flags.
332
333       If X509_VP_FLAG_DEFAULT is set then anything set in the source is
334       copied to the destination. Effectively the values in "to" become
335       default values which will be used only if nothing new is set in "from".
336       This is the default.
337
338       If X509_VP_FLAG_OVERWRITE is set then all value are copied across
339       whether they are set or not. Flags is still Ored though.
340
341       If X509_VP_FLAG_RESET_FLAGS is set then the flags value is copied
342       instead of ORed.
343

NOTES

345       The above functions should be used to manipulate verification
346       parameters instead of functions which work in specific structures such
347       as X509_STORE_CTX_set_flags() which are likely to be deprecated in a
348       future release.
349

BUGS

351       Delta CRL checking is currently primitive. Only a single delta can be
352       used and (partly due to limitations of X509_STORE) constructed CRLs are
353       not maintained.
354
355       If CRLs checking is enable CRLs are expected to be available in the
356       corresponding X509_STORE structure. No attempt is made to download CRLs
357       from the CRL distribution points extension.
358

EXAMPLES

360       Enable CRL checking when performing certificate verification during SSL
361       connections associated with an SSL_CTX structure ctx:
362
363        X509_VERIFY_PARAM *param;
364
365        param = X509_VERIFY_PARAM_new();
366        X509_VERIFY_PARAM_set_flags(param, X509_V_FLAG_CRL_CHECK);
367        SSL_CTX_set1_param(ctx, param);
368        X509_VERIFY_PARAM_free(param);
369

SEE ALSO

371       X509_verify_cert(3), X509_check_host(3), X509_check_email(3),
372       X509_check_ip(3), openssl-x509(1)
373

HISTORY

375       The X509_V_FLAG_NO_ALT_CHAINS flag was added in OpenSSL 1.1.0.  The
376       flag X509_V_FLAG_CB_ISSUER_CHECK was deprecated in OpenSSL 1.1.0 and
377       has no effect.
378
379       The X509_VERIFY_PARAM_get_hostflags() function was added in OpenSSL
380       1.1.0i.
381
382       The X509_VERIFY_PARAM_get0_host(), X509_VERIFY_PARAM_get0_email(), and
383       X509_VERIFY_PARAM_get1_ip_asc() functions were added in OpenSSL 3.0.
384
385       The function X509_VERIFY_PARAM_add0_policy() was historically
386       documented as enabling policy checking however the implementation has
387       never done this.  The documentation was changed to align with the
388       implementation.
389
391       Copyright 2009-2023 The OpenSSL Project Authors. All Rights Reserved.
392
393       Licensed under the Apache License 2.0 (the "License").  You may not use
394       this file except in compliance with the License.  You can obtain a copy
395       in the file LICENSE in the source distribution or at
396       <https://www.openssl.org/source/license.html>.
397
398
399
4003.0.9                             2023-07-27X509_VERIFY_PARAM_SET_FLAGS(3ossl)
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