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