5 X509_VERIFY_PARAM_set_flags, X509_VERIFY_PARAM_clear_flags,
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_add0_policy, X509_VERIFY_PARAM_set1_policies,
13 X509_VERIFY_PARAM_set1_host, X509_VERIFY_PARAM_add1_host,
14 X509_VERIFY_PARAM_set_hostflags, X509_VERIFY_PARAM_get0_peername,
15 X509_VERIFY_PARAM_set1_email, X509_VERIFY_PARAM_set1_ip,
16 X509_VERIFY_PARAM_set1_ip_asc
17 - X509 verification parameters
21 #include <openssl/x509_vfy.h>
23 int X509_VERIFY_PARAM_set_flags(X509_VERIFY_PARAM *param,
25 int X509_VERIFY_PARAM_clear_flags(X509_VERIFY_PARAM *param,
27 unsigned long X509_VERIFY_PARAM_get_flags(X509_VERIFY_PARAM *param);
29 int X509_VERIFY_PARAM_set_inh_flags(X509_VERIFY_PARAM *param,
31 uint32_t X509_VERIFY_PARAM_get_inh_flags(const X509_VERIFY_PARAM *param);
33 int X509_VERIFY_PARAM_set_purpose(X509_VERIFY_PARAM *param, int purpose);
34 int X509_VERIFY_PARAM_set_trust(X509_VERIFY_PARAM *param, int trust);
36 void X509_VERIFY_PARAM_set_time(X509_VERIFY_PARAM *param, time_t t);
38 int X509_VERIFY_PARAM_add0_policy(X509_VERIFY_PARAM *param,
40 int X509_VERIFY_PARAM_set1_policies(X509_VERIFY_PARAM *param,
41 STACK_OF(ASN1_OBJECT) *policies);
43 void X509_VERIFY_PARAM_set_depth(X509_VERIFY_PARAM *param, int depth);
44 int X509_VERIFY_PARAM_get_depth(const X509_VERIFY_PARAM *param);
46 void X509_VERIFY_PARAM_set_auth_level(X509_VERIFY_PARAM *param,
48 int X509_VERIFY_PARAM_get_auth_level(const X509_VERIFY_PARAM *param);
50 int X509_VERIFY_PARAM_set1_host(X509_VERIFY_PARAM *param,
51 const char *name, size_t namelen);
52 int X509_VERIFY_PARAM_add1_host(X509_VERIFY_PARAM *param,
53 const char *name, size_t namelen);
54 void X509_VERIFY_PARAM_set_hostflags(X509_VERIFY_PARAM *param,
56 char *X509_VERIFY_PARAM_get0_peername(X509_VERIFY_PARAM *param);
57 int X509_VERIFY_PARAM_set1_email(X509_VERIFY_PARAM *param,
58 const char *email, size_t emaillen);
59 int X509_VERIFY_PARAM_set1_ip(X509_VERIFY_PARAM *param,
60 const unsigned char *ip, size_t iplen);
61 int X509_VERIFY_PARAM_set1_ip_asc(X509_VERIFY_PARAM *param, const char *ipasc);
65 These functions manipulate the B<X509_VERIFY_PARAM> structure associated with
66 a certificate verification operation.
68 The X509_VERIFY_PARAM_set_flags() function sets the flags in B<param> by oring
69 it with B<flags>. See the B<VERIFICATION FLAGS> section for a complete
70 description of values the B<flags> parameter can take.
72 X509_VERIFY_PARAM_get_flags() returns the flags in B<param>.
74 X509_VERIFY_PARAM_get_inh_flags() returns the inheritance flags in B<param>
75 which specifies how verification flags are copied from one structure to
76 another. X509_VERIFY_PARAM_set_inh_flags() sets the inheritance flags.
77 See the B<INHERITANCE FLAGS> section for a description of these bits.
79 X509_VERIFY_PARAM_clear_flags() clears the flags B<flags> in B<param>.
81 X509_VERIFY_PARAM_set_purpose() sets the verification purpose in B<param>
82 to B<purpose>. This determines the acceptable purpose of the certificate
83 chain, for example SSL client or SSL server.
85 X509_VERIFY_PARAM_set_trust() sets the trust setting in B<param> to
88 X509_VERIFY_PARAM_set_time() sets the verification time in B<param> to
89 B<t>. Normally the current time is used.
91 X509_VERIFY_PARAM_add0_policy() enables policy checking (it is disabled
92 by default) and adds B<policy> to the acceptable policy set.
94 X509_VERIFY_PARAM_set1_policies() enables policy checking (it is disabled
95 by default) and sets the acceptable policy set to B<policies>. Any existing
96 policy set is cleared. The B<policies> parameter can be B<NULL> to clear
97 an existing policy set.
99 X509_VERIFY_PARAM_set_depth() sets the maximum verification depth to B<depth>.
100 That is the maximum number of intermediate CA certificates that can appear in a
102 A maximal depth chain contains 2 more certificates than the limit, since
103 neither the end-entity certificate nor the trust-anchor count against this
105 Thus a B<depth> limit of 0 only allows the end-entity certificate to be signed
106 directly by the trust-anchor, while with a B<depth> limit of 1 there can be one
107 intermediate CA certificate between the trust-anchor and the end-entity
110 X509_VERIFY_PARAM_set_auth_level() sets the authentication security level to
112 The authentication security level determines the acceptable signature and public
113 key strength when verifying certificate chains.
114 For a certificate chain to validate, the public keys of all the certificates
115 must meet the specified security level.
116 The signature algorithm security level is not enforced for the chain's I<trust
117 anchor> certificate, which is either directly trusted or validated by means other
119 See L<SSL_CTX_set_security_level(3)> for the definitions of the available
121 The default security level is -1, or "not set".
122 At security level 0 or lower all algorithms are acceptable.
123 Security level 1 requires at least 80-bit-equivalent security and is broadly
124 interoperable, though it will, for example, reject MD5 signatures or RSA keys
125 shorter than 1024 bits.
127 X509_VERIFY_PARAM_set1_host() sets the expected DNS hostname to
128 B<name> clearing any previously specified host name or names. If
129 B<name> is NULL, or empty the list of hostnames is cleared, and
130 name checks are not performed on the peer certificate. If B<name>
131 is NUL-terminated, B<namelen> may be zero, otherwise B<namelen>
132 must be set to the length of B<name>. When a hostname is specified,
133 certificate verification automatically invokes L<X509_check_host(3)>
134 with flags equal to the B<flags> argument given to
135 X509_VERIFY_PARAM_set_hostflags() (default zero). Applications
136 are strongly advised to use this interface in preference to explicitly
137 calling L<X509_check_host(3)>, hostname checks are out of scope
138 with the DANE-EE(3) certificate usage, and the internal check will
139 be suppressed as appropriate when DANE support is added to OpenSSL.
141 X509_VERIFY_PARAM_add1_host() adds B<name> as an additional reference
142 identifier that can match the peer's certificate. Any previous names
143 set via X509_VERIFY_PARAM_set1_host() or X509_VERIFY_PARAM_add1_host()
144 are retained, no change is made if B<name> is NULL or empty. When
145 multiple names are configured, the peer is considered verified when
148 X509_VERIFY_PARAM_get0_peername() returns the DNS hostname or subject
149 CommonName from the peer certificate that matched one of the reference
150 identifiers. When wildcard matching is not disabled, or when a
151 reference identifier specifies a parent domain (starts with ".")
152 rather than a hostname, the peer name may be a wildcard name or a
153 sub-domain of the reference identifier respectively. The return
154 string is allocated by the library and is no longer valid once the
155 associated B<param> argument is freed. Applications must not free
158 X509_VERIFY_PARAM_set1_email() sets the expected RFC822 email address to
159 B<email>. If B<email> is NUL-terminated, B<emaillen> may be zero, otherwise
160 B<emaillen> must be set to the length of B<email>. When an email address
161 is specified, certificate verification automatically invokes
162 L<X509_check_email(3)>.
164 X509_VERIFY_PARAM_set1_ip() sets the expected IP address to B<ip>.
165 The B<ip> argument is in binary format, in network byte-order and
166 B<iplen> must be set to 4 for IPv4 and 16 for IPv6. When an IP
167 address is specified, certificate verification automatically invokes
170 X509_VERIFY_PARAM_set1_ip_asc() sets the expected IP address to
171 B<ipasc>. The B<ipasc> argument is a NUL-terminal ASCII string:
172 dotted decimal quad for IPv4 and colon-separated hexadecimal for
173 IPv6. The condensed "::" notation is supported for IPv6 addresses.
177 X509_VERIFY_PARAM_set_flags(), X509_VERIFY_PARAM_clear_flags(),
178 X509_VERIFY_PARAM_set_inh_flags(),
179 X509_VERIFY_PARAM_set_purpose(), X509_VERIFY_PARAM_set_trust(),
180 X509_VERIFY_PARAM_add0_policy() X509_VERIFY_PARAM_set1_policies(),
181 X509_VERIFY_PARAM_set1_host(), X509_VERIFY_PARAM_add1_host(),
182 X509_VERIFY_PARAM_set1_email(), X509_VERIFY_PARAM_set1_ip() and
183 X509_VERIFY_PARAM_set1_ip_asc() return 1 for success and 0 for
186 X509_VERIFY_PARAM_get_flags() returns the current verification flags.
188 X509_VERIFY_PARAM_get_inh_flags() returns the current inheritance flags.
190 X509_VERIFY_PARAM_set_time() and X509_VERIFY_PARAM_set_depth() do not return
193 X509_VERIFY_PARAM_get_depth() returns the current verification depth.
195 X509_VERIFY_PARAM_get_auth_level() returns the current authentication security
198 =head1 VERIFICATION FLAGS
200 The verification flags consists of zero or more of the following flags
203 B<X509_V_FLAG_CRL_CHECK> enables CRL checking for the certificate chain leaf
204 certificate. An error occurs if a suitable CRL cannot be found.
206 B<X509_V_FLAG_CRL_CHECK_ALL> enables CRL checking for the entire certificate
209 B<X509_V_FLAG_IGNORE_CRITICAL> disabled critical extension checking. By default
210 any unhandled critical extensions in certificates or (if checked) CRLs results
211 in a fatal error. If this flag is set unhandled critical extensions are
212 ignored. B<WARNING> setting this option for anything other than debugging
213 purposes can be a security risk. Finer control over which extensions are
214 supported can be performed in the verification callback.
216 The B<X509_V_FLAG_X509_STRICT> flag disables workarounds for some broken
217 certificates and makes the verification strictly apply B<X509> rules.
219 B<X509_V_FLAG_ALLOW_PROXY_CERTS> enables proxy certificate verification.
221 B<X509_V_FLAG_POLICY_CHECK> enables certificate policy checking, by default
222 no policy checking is performed. Additional information is sent to the
223 verification callback relating to policy checking.
225 B<X509_V_FLAG_EXPLICIT_POLICY>, B<X509_V_FLAG_INHIBIT_ANY> and
226 B<X509_V_FLAG_INHIBIT_MAP> set the B<require explicit policy>, B<inhibit any
227 policy> and B<inhibit policy mapping> flags respectively as defined in
228 B<RFC3280>. Policy checking is automatically enabled if any of these flags
231 If B<X509_V_FLAG_NOTIFY_POLICY> is set and the policy checking is successful
232 a special status code is set to the verification callback. This permits it
233 to examine the valid policy tree and perform additional checks or simply
234 log it for debugging purposes.
236 By default some additional features such as indirect CRLs and CRLs signed by
237 different keys are disabled. If B<X509_V_FLAG_EXTENDED_CRL_SUPPORT> is set
240 If B<X509_V_FLAG_USE_DELTAS> is set delta CRLs (if present) are used to
241 determine certificate status. If not set deltas are ignored.
243 B<X509_V_FLAG_CHECK_SS_SIGNATURE> enables checking of the root CA self signed
244 certificate signature. By default this check is disabled because it doesn't
245 add any additional security but in some cases applications might want to
246 check the signature anyway. A side effect of not checking the root CA
247 signature is that disabled or unsupported message digests on the root CA
248 are not treated as fatal errors.
250 If B<X509_V_FLAG_TRUSTED_FIRST> is set, when constructing the certificate chain,
251 L<X509_verify_cert(3)> will search the trust store for issuer certificates before
252 searching the provided untrusted certificates.
253 As of OpenSSL 1.1.0 this option is on by default and cannot be disabled.
255 The B<X509_V_FLAG_NO_ALT_CHAINS> flag suppresses checking for alternative
257 By default, unless B<X509_V_FLAG_TRUSTED_FIRST> is set, when building a
258 certificate chain, if the first certificate chain found is not trusted, then
259 OpenSSL will attempt to replace untrusted certificates supplied by the peer
260 with certificates from the trust store to see if an alternative chain can be
261 found that is trusted.
262 As of OpenSSL 1.1.0, with B<X509_V_FLAG_TRUSTED_FIRST> always set, this option
265 The B<X509_V_FLAG_NO_CHECK_TIME> flag suppresses checking the validity period
266 of certificates and CRLs against the current time. If X509_VERIFY_PARAM_set_time()
267 is used to specify a verification time, the check is not suppressed.
269 =head1 INHERITANCE FLAGS
271 These flags spevify how parameters are "inherited" from one structure to
274 If B<X509_VP_FLAG_ONCE> is set then the current setting is zeroed
277 If B<X509_VP_FLAG_LOCKED> is set then no values are copied. This overrides
278 all of the following flags.
280 If B<X509_VP_FLAG_DEFAULT> is set then anything set in the source is copied
281 to the destination. Effectively the values in "to" become default values
282 which will be used only if nothing new is set in "from". This is the
285 If B<X509_VP_FLAG_OVERWRITE> is set then all value are copied across whether
286 they are set or not. Flags is still Ored though.
288 If B<X509_VP_FLAG_RESET_FLAGS> is set then the flags value is copied instead
293 The above functions should be used to manipulate verification parameters
294 instead of legacy functions which work in specific structures such as
295 X509_STORE_CTX_set_flags().
299 Delta CRL checking is currently primitive. Only a single delta can be used and
300 (partly due to limitations of B<X509_STORE>) constructed CRLs are not
303 If CRLs checking is enable CRLs are expected to be available in the
304 corresponding B<X509_STORE> structure. No attempt is made to download
305 CRLs from the CRL distribution points extension.
309 Enable CRL checking when performing certificate verification during SSL
310 connections associated with an B<SSL_CTX> structure B<ctx>:
312 X509_VERIFY_PARAM *param;
313 param = X509_VERIFY_PARAM_new();
314 X509_VERIFY_PARAM_set_flags(param, X509_V_FLAG_CRL_CHECK);
315 SSL_CTX_set1_param(ctx, param);
316 X509_VERIFY_PARAM_free(param);
320 L<X509_verify_cert(3)>,
321 L<X509_check_host(3)>,
322 L<X509_check_email(3)>,
327 The B<X509_V_FLAG_NO_ALT_CHAINS> flag was added in OpenSSL 1.1.0
328 The legacy B<X509_V_FLAG_CB_ISSUER_CHECK> flag is deprecated as of
329 OpenSSL 1.1.0, and has no effect.
333 Copyright 2009-2016 The OpenSSL Project Authors. All Rights Reserved.
335 Licensed under the OpenSSL license (the "License"). You may not use
336 this file except in compliance with the License. You can obtain a copy
337 in the file LICENSE in the source distribution or at
338 L<https://www.openssl.org/source/license.html>.