5 X509_VERIFY_PARAM_set_flags, X509_VERIFY_PARAM_clear_flags, X509_VERIFY_PARAM_get_flags, X509_VERIFY_PARAM_set_purpose, X509_VERIFY_PARAM_set_trust, X509_VERIFY_PARAM_set_depth, X509_VERIFY_PARAM_get_depth, X509_VERIFY_PARAM_set_auth_level, X509_VERIFY_PARAM_get_auth_level, X509_VERIFY_PARAM_set_time, X509_VERIFY_PARAM_add0_policy, X509_VERIFY_PARAM_set1_policies, X509_VERIFY_PARAM_set1_host, X509_VERIFY_PARAM_add1_host, X509_VERIFY_PARAM_set_hostflags, X509_VERIFY_PARAM_get0_peername, X509_VERIFY_PARAM_set1_email, X509_VERIFY_PARAM_set1_ip, X509_VERIFY_PARAM_set1_ip_asc - X509 verification parameters
9 #include <openssl/x509_vfy.h>
11 int X509_VERIFY_PARAM_set_flags(X509_VERIFY_PARAM *param,
13 int X509_VERIFY_PARAM_clear_flags(X509_VERIFY_PARAM *param,
15 unsigned long X509_VERIFY_PARAM_get_flags(X509_VERIFY_PARAM *param);
17 int X509_VERIFY_PARAM_set_purpose(X509_VERIFY_PARAM *param, int purpose);
18 int X509_VERIFY_PARAM_set_trust(X509_VERIFY_PARAM *param, int trust);
20 void X509_VERIFY_PARAM_set_time(X509_VERIFY_PARAM *param, time_t t);
22 int X509_VERIFY_PARAM_add0_policy(X509_VERIFY_PARAM *param,
24 int X509_VERIFY_PARAM_set1_policies(X509_VERIFY_PARAM *param,
25 STACK_OF(ASN1_OBJECT) *policies);
27 void X509_VERIFY_PARAM_set_depth(X509_VERIFY_PARAM *param, int depth);
28 int X509_VERIFY_PARAM_get_depth(const X509_VERIFY_PARAM *param);
30 void X509_VERIFY_PARAM_set_auth_level(X509_VERIFY_PARAM *param,
32 int X509_VERIFY_PARAM_get_auth_level(const X509_VERIFY_PARAM *param);
34 int X509_VERIFY_PARAM_set1_host(X509_VERIFY_PARAM *param,
35 const char *name, size_t namelen);
36 int X509_VERIFY_PARAM_add1_host(X509_VERIFY_PARAM *param,
37 const char *name, size_t namelen);
38 void X509_VERIFY_PARAM_set_hostflags(X509_VERIFY_PARAM *param,
40 char *X509_VERIFY_PARAM_get0_peername(X509_VERIFY_PARAM *param);
41 int X509_VERIFY_PARAM_set1_email(X509_VERIFY_PARAM *param,
42 const char *email, size_t emaillen);
43 int X509_VERIFY_PARAM_set1_ip(X509_VERIFY_PARAM *param,
44 const unsigned char *ip, size_t iplen);
45 int X509_VERIFY_PARAM_set1_ip_asc(X509_VERIFY_PARAM *param, const char *ipasc);
49 These functions manipulate the B<X509_VERIFY_PARAM> structure associated with
50 a certificate verification operation.
52 The X509_VERIFY_PARAM_set_flags() function sets the flags in B<param> by oring
53 it with B<flags>. See the B<VERIFICATION FLAGS> section for a complete
54 description of values the B<flags> parameter can take.
56 X509_VERIFY_PARAM_get_flags() returns the flags in B<param>.
58 X509_VERIFY_PARAM_clear_flags() clears the flags B<flags> in B<param>.
60 X509_VERIFY_PARAM_set_purpose() sets the verification purpose in B<param>
61 to B<purpose>. This determines the acceptable purpose of the certificate
62 chain, for example SSL client or SSL server.
64 X509_VERIFY_PARAM_set_trust() sets the trust setting in B<param> to
67 X509_VERIFY_PARAM_set_time() sets the verification time in B<param> to
68 B<t>. Normally the current time is used.
70 X509_VERIFY_PARAM_add0_policy() enables policy checking (it is disabled
71 by default) and adds B<policy> to the acceptable policy set.
73 X509_VERIFY_PARAM_set1_policies() enables policy checking (it is disabled
74 by default) and sets the acceptable policy set to B<policies>. Any existing
75 policy set is cleared. The B<policies> parameter can be B<NULL> to clear
76 an existing policy set.
78 X509_VERIFY_PARAM_set_depth() sets the maximum verification depth to B<depth>.
79 That is the maximum number of intermediate CA certificates that can appear in a
81 A maximal depth chain contains 2 more certificates than the limit, since
82 neither the end-entity certificate nor the trust-anchor count against this
84 Thus a B<depth> limit of 0 only allows the end-entity certificate to be signed
85 directly by the trust-anchor, while with a B<depth> limit of 1 there can be one
86 intermediate CA certificate between the trust-anchor and the end-entity
89 X509_VERIFY_PARAM_set_auth_level() sets the authentication security level to
91 The authentication security level determines the acceptable signature and public
92 key strength when verifying certificate chains.
93 For a certificate chain to validate, the public keys of all the certificates
94 must meet the specified security level.
95 The signature algorithm security level is not enforced for the chain's I<trust
96 anchor> certificate, which is either directly trusted or validated by means other
98 See L<SSL_CTX_set_security_level(3)> for the definitions of the available
100 The default security level is -1, or "not set".
101 At security level 0 or lower all algorithms are acceptable.
102 Security level 1 requires at least 80-bit-equivalent security and is broadly
103 interoperable, though it will, for example, reject MD5 signatures or RSA keys
104 shorter than 1024 bits.
106 X509_VERIFY_PARAM_set1_host() sets the expected DNS hostname to
107 B<name> clearing any previously specified host name or names. If
108 B<name> is NULL, or empty the list of hostnames is cleared, and
109 name checks are not performed on the peer certificate. If B<name>
110 is NUL-terminated, B<namelen> may be zero, otherwise B<namelen>
111 must be set to the length of B<name>. When a hostname is specified,
112 certificate verification automatically invokes L<X509_check_host(3)>
113 with flags equal to the B<flags> argument given to
114 X509_VERIFY_PARAM_set_hostflags() (default zero). Applications
115 are strongly advised to use this interface in preference to explicitly
116 calling L<X509_check_host(3)>, hostname checks are out of scope
117 with the DANE-EE(3) certificate usage, and the internal check will
118 be suppressed as appropriate when DANE support is added to OpenSSL.
120 X509_VERIFY_PARAM_add1_host() adds B<name> as an additional reference
121 identifier that can match the peer's certificate. Any previous names
122 set via X509_VERIFY_PARAM_set1_host() or X509_VERIFY_PARAM_add1_host()
123 are retained, no change is made if B<name> is NULL or empty. When
124 multiple names are configured, the peer is considered verified when
127 X509_VERIFY_PARAM_get0_peername() returns the DNS hostname or subject
128 CommonName from the peer certificate that matched one of the reference
129 identifiers. When wildcard matching is not disabled, or when a
130 reference identifier specifies a parent domain (starts with ".")
131 rather than a hostname, the peer name may be a wildcard name or a
132 sub-domain of the reference identifier respectively. The return
133 string is allocated by the library and is no longer valid once the
134 associated B<param> argument is freed. Applications must not free
137 X509_VERIFY_PARAM_set1_email() sets the expected RFC822 email address to
138 B<email>. If B<email> is NUL-terminated, B<emaillen> may be zero, otherwise
139 B<emaillen> must be set to the length of B<email>. When an email address
140 is specified, certificate verification automatically invokes
141 L<X509_check_email(3)>.
143 X509_VERIFY_PARAM_set1_ip() sets the expected IP address to B<ip>.
144 The B<ip> argument is in binary format, in network byte-order and
145 B<iplen> must be set to 4 for IPv4 and 16 for IPv6. When an IP
146 address is specified, certificate verification automatically invokes
149 X509_VERIFY_PARAM_set1_ip_asc() sets the expected IP address to
150 B<ipasc>. The B<ipasc> argument is a NUL-terminal ASCII string:
151 dotted decimal quad for IPv4 and colon-separated hexadecimal for
152 IPv6. The condensed "::" notation is supported for IPv6 addresses.
156 X509_VERIFY_PARAM_set_flags(), X509_VERIFY_PARAM_clear_flags(),
157 X509_VERIFY_PARAM_set_purpose(), X509_VERIFY_PARAM_set_trust(),
158 X509_VERIFY_PARAM_add0_policy() X509_VERIFY_PARAM_set1_policies(),
159 X509_VERIFY_PARAM_set1_host(), X509_VERIFY_PARAM_add1_host(),
160 X509_VERIFY_PARAM_set1_email(), X509_VERIFY_PARAM_set1_ip() and
161 X509_VERIFY_PARAM_set1_ip_asc() return 1 for success and 0 for
164 X509_VERIFY_PARAM_get_flags() returns the current verification flags.
166 X509_VERIFY_PARAM_set_time() and X509_VERIFY_PARAM_set_depth() do not return
169 X509_VERIFY_PARAM_get_depth() returns the current verification depth.
171 X509_VERIFY_PARAM_get_auth_level() returns the current authentication security
174 =head1 VERIFICATION FLAGS
176 The verification flags consists of zero or more of the following flags
179 B<X509_V_FLAG_CRL_CHECK> enables CRL checking for the certificate chain leaf
180 certificate. An error occurs if a suitable CRL cannot be found.
182 B<X509_V_FLAG_CRL_CHECK_ALL> enables CRL checking for the entire certificate
185 B<X509_V_FLAG_IGNORE_CRITICAL> disabled critical extension checking. By default
186 any unhandled critical extensions in certificates or (if checked) CRLs results
187 in a fatal error. If this flag is set unhandled critical extensions are
188 ignored. B<WARNING> setting this option for anything other than debugging
189 purposes can be a security risk. Finer control over which extensions are
190 supported can be performed in the verification callback.
192 The B<X509_V_FLAG_X509_STRICT> flag disables workarounds for some broken
193 certificates and makes the verification strictly apply B<X509> rules.
195 B<X509_V_FLAG_ALLOW_PROXY_CERTS> enables proxy certificate verification.
197 B<X509_V_FLAG_POLICY_CHECK> enables certificate policy checking, by default
198 no policy checking is performed. Additional information is sent to the
199 verification callback relating to policy checking.
201 B<X509_V_FLAG_EXPLICIT_POLICY>, B<X509_V_FLAG_INHIBIT_ANY> and
202 B<X509_V_FLAG_INHIBIT_MAP> set the B<require explicit policy>, B<inhibit any
203 policy> and B<inhibit policy mapping> flags respectively as defined in
204 B<RFC3280>. Policy checking is automatically enabled if any of these flags
207 If B<X509_V_FLAG_NOTIFY_POLICY> is set and the policy checking is successful
208 a special status code is set to the verification callback. This permits it
209 to examine the valid policy tree and perform additional checks or simply
210 log it for debugging purposes.
212 By default some additional features such as indirect CRLs and CRLs signed by
213 different keys are disabled. If B<X509_V_FLAG_EXTENDED_CRL_SUPPORT> is set
216 If B<X509_V_FLAG_USE_DELTAS> is set delta CRLs (if present) are used to
217 determine certificate status. If not set deltas are ignored.
219 B<X509_V_FLAG_CHECK_SS_SIGNATURE> enables checking of the root CA self signed
220 certificate signature. By default this check is disabled because it doesn't
221 add any additional security but in some cases applications might want to
222 check the signature anyway. A side effect of not checking the root CA
223 signature is that disabled or unsupported message digests on the root CA
224 are not treated as fatal errors.
226 If B<X509_V_FLAG_TRUSTED_FIRST> is set, when constructing the certificate chain,
227 L<X509_verify_cert(3)> will search the trust store for issuer certificates before
228 searching the provided untrusted certificates.
229 As of OpenSSL 1.1.0 this option is on by default and cannot be disabled.
231 The B<X509_V_FLAG_NO_ALT_CHAINS> flag suppresses checking for alternative
233 By default, unless B<X509_V_FLAG_TRUSTED_FIRST> is set, when building a
234 certificate chain, if the first certificate chain found is not trusted, then
235 OpenSSL will attempt to replace untrusted certificates supplied by the peer
236 with certificates from the trust store to see if an alternative chain can be
237 found that is trusted.
238 As of OpenSSL 1.1.0, with B<X509_V_FLAG_TRUSTED_FIRST> always set, this option
241 The B<X509_V_FLAG_NO_CHECK_TIME> flag suppresses checking the validity period
242 of certificates and CRLs against the current time. If X509_VERIFY_PARAM_set_time()
243 is used to specify a verification time, the check is not suppressed.
247 The above functions should be used to manipulate verification parameters
248 instead of legacy functions which work in specific structures such as
249 X509_STORE_CTX_set_flags().
253 Delta CRL checking is currently primitive. Only a single delta can be used and
254 (partly due to limitations of B<X509_STORE>) constructed CRLs are not
257 If CRLs checking is enable CRLs are expected to be available in the
258 corresponding B<X509_STORE> structure. No attempt is made to download
259 CRLs from the CRL distribution points extension.
263 Enable CRL checking when performing certificate verification during SSL
264 connections associated with an B<SSL_CTX> structure B<ctx>:
266 X509_VERIFY_PARAM *param;
267 param = X509_VERIFY_PARAM_new();
268 X509_VERIFY_PARAM_set_flags(param, X509_V_FLAG_CRL_CHECK);
269 SSL_CTX_set1_param(ctx, param);
270 X509_VERIFY_PARAM_free(param);
274 L<X509_verify_cert(3)>,
275 L<X509_check_host(3)>,
276 L<X509_check_email(3)>,
281 The B<X509_V_FLAG_NO_ALT_CHAINS> flag was added in OpenSSL 1.1.0
282 The legacy B<X509_V_FLAG_CB_ISSUER_CHECK> flag is deprecated as of
283 OpenSSL 1.1.0, and has no effect.
287 Copyright 2009-2016 The OpenSSL Project Authors. All Rights Reserved.
289 Licensed under the OpenSSL license (the "License"). You may not use
290 this file except in compliance with the License. You can obtain a copy
291 in the file LICENSE in the source distribution or at
292 L<https://www.openssl.org/source/license.html>.