X509_VERIFY_PARAM_SET_FLAGS(3ossl) OpenSSL X509_VERIFY_PARAM_SET_FLAGS(3ossl)
NAME
X509_VERIFY_PARAM_set_flags, X509_VERIFY_PARAM_clear_flags,
X509_VERIFY_PARAM_get_flags, X509_VERIFY_PARAM_set_purpose,
X509_VERIFY_PARAM_get_inh_flags, X509_VERIFY_PARAM_set_inh_flags,
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_get_time, X509_VERIFY_PARAM_add0_policy,
X509_VERIFY_PARAM_set1_policies, X509_VERIFY_PARAM_get0_host,
X509_VERIFY_PARAM_set1_host, X509_VERIFY_PARAM_add1_host,
X509_VERIFY_PARAM_set_hostflags, X509_VERIFY_PARAM_get_hostflags,
X509_VERIFY_PARAM_get0_peername, X509_VERIFY_PARAM_get0_email,
X509_VERIFY_PARAM_set1_email, X509_VERIFY_PARAM_set1_ip,
X509_VERIFY_PARAM_get1_ip_asc, X509_VERIFY_PARAM_set1_ip_asc - X509
verification parameters
SYNOPSIS
#include <openssl/x509_vfy.h>
int X509_VERIFY_PARAM_set_flags(X509_VERIFY_PARAM *param,
unsigned long flags);
int X509_VERIFY_PARAM_clear_flags(X509_VERIFY_PARAM *param,
unsigned long flags);
unsigned long X509_VERIFY_PARAM_get_flags(const X509_VERIFY_PARAM *param);
int X509_VERIFY_PARAM_set_inh_flags(X509_VERIFY_PARAM *param,
uint32_t flags);
uint32_t X509_VERIFY_PARAM_get_inh_flags(const X509_VERIFY_PARAM *param);
int X509_VERIFY_PARAM_set_purpose(X509_VERIFY_PARAM *param, int purpose);
int X509_VERIFY_PARAM_set_trust(X509_VERIFY_PARAM *param, int trust);
void X509_VERIFY_PARAM_set_time(X509_VERIFY_PARAM *param, time_t t);
time_t X509_VERIFY_PARAM_get_time(const X509_VERIFY_PARAM *param);
int X509_VERIFY_PARAM_add0_policy(X509_VERIFY_PARAM *param,
ASN1_OBJECT *policy);
int X509_VERIFY_PARAM_set1_policies(X509_VERIFY_PARAM *param,
STACK_OF(ASN1_OBJECT) *policies);
void X509_VERIFY_PARAM_set_depth(X509_VERIFY_PARAM *param, int depth);
int X509_VERIFY_PARAM_get_depth(const X509_VERIFY_PARAM *param);
void X509_VERIFY_PARAM_set_auth_level(X509_VERIFY_PARAM *param,
int auth_level);
int X509_VERIFY_PARAM_get_auth_level(const X509_VERIFY_PARAM *param);
char *X509_VERIFY_PARAM_get0_host(X509_VERIFY_PARAM *param, int n);
int X509_VERIFY_PARAM_set1_host(X509_VERIFY_PARAM *param,
const char *name, size_t namelen);
int X509_VERIFY_PARAM_add1_host(X509_VERIFY_PARAM *param,
const char *name, size_t namelen);
void X509_VERIFY_PARAM_set_hostflags(X509_VERIFY_PARAM *param,
unsigned int flags);
unsigned int X509_VERIFY_PARAM_get_hostflags(const X509_VERIFY_PARAM *param);
char *X509_VERIFY_PARAM_get0_peername(const X509_VERIFY_PARAM *param);
char *X509_VERIFY_PARAM_get0_email(X509_VERIFY_PARAM *param);
int X509_VERIFY_PARAM_set1_email(X509_VERIFY_PARAM *param,
const char *email, size_t emaillen);
char *X509_VERIFY_PARAM_get1_ip_asc(X509_VERIFY_PARAM *param);
int X509_VERIFY_PARAM_set1_ip(X509_VERIFY_PARAM *param,
const unsigned char *ip, size_t iplen);
int X509_VERIFY_PARAM_set1_ip_asc(X509_VERIFY_PARAM *param, const char *ipasc);
DESCRIPTION
These functions manipulate the X509_VERIFY_PARAM structure associated
with a certificate verification operation.
The X509_VERIFY_PARAM_set_flags(3) function sets the flags in param by
oring it with flags. See "VERIFICATION FLAGS" for a complete
description of values the flags parameter can take.
X509_VERIFY_PARAM_get_flags() returns the flags in param.
X509_VERIFY_PARAM_get_inh_flags() returns the inheritance flags in
param which specifies how verification flags are copied from one
structure to another. X509_VERIFY_PARAM_set_inh_flags() sets the
inheritance flags. See the INHERITANCE FLAGS section for a description
of these bits.
X509_VERIFY_PARAM_clear_flags() clears the flags flags in param.
X509_VERIFY_PARAM_set_purpose() sets the verification purpose in param
to purpose. This determines the acceptable purpose of the certificate
chain, for example X509_PURPOSE_SSL_CLIENT. The purpose requirement is
cleared if purpose is 0.
X509_VERIFY_PARAM_set_trust() sets the trust setting in param to trust.
X509_VERIFY_PARAM_set_time() sets the verification time in param to t.
Normally the current time is used.
X509_VERIFY_PARAM_add0_policy() adds policy to the acceptable policy
set. Contrary to preexisting documentation of this function it does
not enable policy checking.
X509_VERIFY_PARAM_set1_policies() enables policy checking (it is
disabled by default) and sets the acceptable policy set to policies.
Any existing policy set is cleared. The policies parameter can be NULL
to clear an existing policy set.
X509_VERIFY_PARAM_set_depth() sets the maximum verification depth to
depth. That is the maximum number of intermediate CA certificates that
can appear in a chain. A maximal depth chain contains 2 more
certificates than the limit, since neither the end-entity certificate
nor the trust-anchor count against this limit. Thus a depth limit of 0
only allows the end-entity certificate to be signed directly by the
trust anchor, while with a depth limit of 1 there can be one
intermediate CA certificate between the trust anchor and the end-entity
certificate.
X509_VERIFY_PARAM_set_auth_level() sets the authentication security
level to auth_level. The authentication security level determines the
acceptable signature and public key strength when verifying certificate
chains. For a certificate chain to validate, the public keys of all
the certificates must meet the specified security level. The signature
algorithm security level is not enforced for the chain's trust anchor
certificate, which is either directly trusted or validated by means
other than its signature. See SSL_CTX_set_security_level(3) for the
definitions of the available levels. The default security level is -1,
or "not set". At security level 0 or lower all algorithms are
acceptable. Security level 1 requires at least 80-bit-equivalent
security and is broadly interoperable, though it will, for example,
reject MD5 signatures or RSA keys shorter than 1024 bits.
X509_VERIFY_PARAM_get0_host() returns the nth expected DNS hostname
that has been set using X509_VERIFY_PARAM_set1_host() or
X509_VERIFY_PARAM_add1_host(). To obtain all names start with n = 0
and increment n as long as no NULL pointer is returned.
X509_VERIFY_PARAM_set1_host() sets the expected DNS hostname to name
clearing any previously specified hostname. If name is NULL, or empty
the list of hostnames is cleared, and name checks are not performed on
the peer certificate. If name is NUL-terminated, namelen may be zero,
otherwise namelen must be set to the length of name.
When a hostname is specified, certificate verification automatically
invokes X509_check_host(3) with flags equal to the flags argument given
to X509_VERIFY_PARAM_set_hostflags() (default zero). Applications are
strongly advised to use this interface in preference to explicitly
calling X509_check_host(3), hostname checks may be out of scope with
the DANE-EE(3) certificate usage, and the internal check will be
suppressed as appropriate when DANE verification is enabled.
When the subject CommonName will not be ignored, whether as a result of
the X509_CHECK_FLAG_ALWAYS_CHECK_SUBJECT host flag, or because no DNS
subject alternative names are present in the certificate, any DNS name
constraints in issuer certificates apply to the subject CommonName as
well as the subject alternative name extension.
When the subject CommonName will be ignored, whether as a result of the
X509_CHECK_FLAG_NEVER_CHECK_SUBJECT host flag, or because some DNS
subject alternative names are present in the certificate, DNS name
constraints in issuer certificates will not be applied to the subject
DN. As described in X509_check_host(3) the
X509_CHECK_FLAG_NEVER_CHECK_SUBJECT flag takes precedence over the
X509_CHECK_FLAG_ALWAYS_CHECK_SUBJECT flag.
X509_VERIFY_PARAM_get_hostflags() returns any host flags previously set
via a call to X509_VERIFY_PARAM_set_hostflags().
X509_VERIFY_PARAM_add1_host() adds name as an additional reference
identifier that can match the peer's certificate. Any previous names
set via X509_VERIFY_PARAM_set1_host() or X509_VERIFY_PARAM_add1_host()
are retained, no change is made if name is NULL or empty. When
multiple names are configured, the peer is considered verified when any
name matches.
X509_VERIFY_PARAM_get0_peername() returns the DNS hostname or subject
CommonName from the peer certificate that matched one of the reference
identifiers. When wildcard matching is not disabled, or when a
reference identifier specifies a parent domain (starts with ".") rather
than a hostname, the peer name may be a wildcard name or a sub-domain
of the reference identifier respectively. The return string is
allocated by the library and is no longer valid once the associated
param argument is freed. Applications must not free the return value.
X509_VERIFY_PARAM_get0_email() returns the expected RFC822 email
address.
X509_VERIFY_PARAM_set1_email() sets the expected RFC822 email address
to email. If email is NUL-terminated, emaillen may be zero, otherwise
emaillen must be set to the length of email. When an email address is
specified, certificate verification automatically invokes
X509_check_email(3).
X509_VERIFY_PARAM_get1_ip_asc() returns the expected IP address as a
string. The caller is responsible for freeing it.
X509_VERIFY_PARAM_set1_ip() sets the expected IP address to ip. The ip
argument is in binary format, in network byte-order and iplen must be
set to 4 for IPv4 and 16 for IPv6. When an IP address is specified,
certificate verification automatically invokes X509_check_ip(3).
X509_VERIFY_PARAM_set1_ip_asc() sets the expected IP address to ipasc.
The ipasc argument is a NUL-terminal ASCII string: dotted decimal quad
for IPv4 and colon-separated hexadecimal for IPv6. The condensed "::"
notation is supported for IPv6 addresses.
RETURN VALUES
X509_VERIFY_PARAM_set_flags(3), X509_VERIFY_PARAM_clear_flags(),
X509_VERIFY_PARAM_set_inh_flags(), X509_VERIFY_PARAM_set_purpose(),
X509_VERIFY_PARAM_set_trust(), X509_VERIFY_PARAM_add0_policy()
X509_VERIFY_PARAM_set1_policies(), X509_VERIFY_PARAM_set1_host(),
X509_VERIFY_PARAM_add1_host(), X509_VERIFY_PARAM_set1_email(),
X509_VERIFY_PARAM_set1_ip() and X509_VERIFY_PARAM_set1_ip_asc() return
1 for success and 0 for failure.
X509_VERIFY_PARAM_get0_host(), X509_VERIFY_PARAM_get0_email(), and
X509_VERIFY_PARAM_get1_ip_asc(), return the string pointers specified
above or NULL if the respective value has not been set or on error.
X509_VERIFY_PARAM_get_flags() returns the current verification flags.
X509_VERIFY_PARAM_get_hostflags() returns any current host flags.
X509_VERIFY_PARAM_get_inh_flags() returns the current inheritance
flags.
X509_VERIFY_PARAM_set_time() and X509_VERIFY_PARAM_set_depth() do not
return values.
X509_VERIFY_PARAM_get_depth() returns the current verification depth.
X509_VERIFY_PARAM_get_auth_level() returns the current authentication
security level.
VERIFICATION FLAGS
The verification flags consists of zero or more of the following flags
ored together.
X509_V_FLAG_CRL_CHECK enables CRL checking for the certificate chain
leaf certificate. An error occurs if a suitable CRL cannot be found.
X509_V_FLAG_CRL_CHECK_ALL enables CRL checking for the entire
certificate chain.
X509_V_FLAG_IGNORE_CRITICAL disables critical extension checking. By
default any unhandled critical extensions in certificates or (if
checked) CRLs result in a fatal error. If this flag is set unhandled
critical extensions are ignored. WARNING setting this option for
anything other than debugging purposes can be a security risk. Finer
control over which extensions are supported can be performed in the
verification callback.
The X509_V_FLAG_X509_STRICT flag disables workarounds for some broken
certificates and makes the verification strictly apply X509 rules.
X509_V_FLAG_ALLOW_PROXY_CERTS enables proxy certificate verification.
X509_V_FLAG_POLICY_CHECK enables certificate policy checking, by
default no policy checking is performed. Additional information is sent
to the verification callback relating to policy checking.
X509_V_FLAG_EXPLICIT_POLICY, X509_V_FLAG_INHIBIT_ANY and
X509_V_FLAG_INHIBIT_MAP set the require explicit policy, inhibit any
policy and inhibit policy mapping flags respectively as defined in
RFC3280. Policy checking is automatically enabled if any of these flags
are set.
If X509_V_FLAG_NOTIFY_POLICY is set and the policy checking is
successful a special status code is set to the verification callback.
This permits it to examine the valid policy tree and perform additional
checks or simply log it for debugging purposes.
By default some additional features such as indirect CRLs and CRLs
signed by different keys are disabled. If
X509_V_FLAG_EXTENDED_CRL_SUPPORT is set they are enabled.
If X509_V_FLAG_USE_DELTAS is set delta CRLs (if present) are used to
determine certificate status. If not set deltas are ignored.
X509_V_FLAG_CHECK_SS_SIGNATURE requests checking the signature of the
last certificate in a chain if the certificate is supposedly
self-signed. This is prohibited and will result in an error if it is a
non-conforming CA certificate with key usage restrictions not including
the keyCertSign bit. By default this check is disabled because it
doesn't add any additional security but in some cases applications
might want to check the signature anyway. A side effect of not checking
the self-signature of such a certificate is that disabled or
unsupported message digests used for the signature are not treated as
fatal errors.
When X509_V_FLAG_TRUSTED_FIRST is set, which is always the case since
OpenSSL 1.1.0, construction of the certificate chain in
X509_verify_cert(3) searches the trust store for issuer certificates
before searching the provided untrusted certificates. Local issuer
certificates are often more likely to satisfy local security
requirements and lead to a locally trusted root. This is especially
important when some certificates in the trust store have explicit trust
settings (see "TRUST SETTINGS" in openssl-x509(1)).
The X509_V_FLAG_NO_ALT_CHAINS flag could have been used before OpenSSL
1.1.0 to suppress checking for alternative chains. By default, unless
X509_V_FLAG_TRUSTED_FIRST is set, when building a certificate chain, if
the first certificate chain found is not trusted, then OpenSSL will
attempt to replace untrusted certificates supplied by the peer with
certificates from the trust store to see if an alternative chain can be
found that is trusted. As of OpenSSL 1.1.0, with
X509_V_FLAG_TRUSTED_FIRST always set, this option has no effect.
The X509_V_FLAG_PARTIAL_CHAIN flag causes non-self-signed certificates
in the trust store to be treated as trust anchors, in the same way as
self-signed root CA certificates. This makes it possible to trust
self-issued certificates as well as certificates issued by an
intermediate CA without having to trust their ancestor root CA. With
OpenSSL 1.1.0 and later and X509_V_FLAG_PARTIAL_CHAIN set, chain
construction stops as soon as the first certificate contained in the
trust store is added to the chain, whether that certificate is a
self-signed "root" certificate or a not self-signed "intermediate" or
self-issued certificate. Thus, when an intermediate certificate is
found in the trust store, the verified chain passed to callbacks may be
shorter than it otherwise would be without the
X509_V_FLAG_PARTIAL_CHAIN flag.
The X509_V_FLAG_NO_CHECK_TIME flag suppresses checking the validity
period of certificates and CRLs against the current time. If
X509_VERIFY_PARAM_set_time() is used to specify a verification time,
the check is not suppressed.
INHERITANCE FLAGS
These flags specify how parameters are "inherited" from one structure
to another.
If X509_VP_FLAG_ONCE is set then the current setting is zeroed after
the next call.
If X509_VP_FLAG_LOCKED is set then no values are copied. This
overrides all of the following flags.
If X509_VP_FLAG_DEFAULT is set then anything set in the source is
copied to the destination. Effectively the values in "to" become
default values which will be used only if nothing new is set in "from".
This is the default.
If X509_VP_FLAG_OVERWRITE is set then all value are copied across
whether they are set or not. Flags is still Ored though.
If X509_VP_FLAG_RESET_FLAGS is set then the flags value is copied
instead of ORed.
NOTES
The above functions should be used to manipulate verification
parameters instead of functions which work in specific structures such
as X509_STORE_CTX_set_flags() which are likely to be deprecated in a
future release.
BUGS
Delta CRL checking is currently primitive. Only a single delta can be
used and (partly due to limitations of X509_STORE) constructed CRLs are
not maintained.
If CRLs checking is enable CRLs are expected to be available in the
corresponding X509_STORE structure. No attempt is made to download CRLs
from the CRL distribution points extension.
EXAMPLES
Enable CRL checking when performing certificate verification during SSL
connections associated with an SSL_CTX structure ctx:
X509_VERIFY_PARAM *param;
param = X509_VERIFY_PARAM_new();
X509_VERIFY_PARAM_set_flags(param, X509_V_FLAG_CRL_CHECK);
SSL_CTX_set1_param(ctx, param);
X509_VERIFY_PARAM_free(param);
SEE ALSO
X509_verify_cert(3), X509_check_host(3), X509_check_email(3),
X509_check_ip(3), openssl-x509(1)
HISTORY
The X509_V_FLAG_NO_ALT_CHAINS flag was added in OpenSSL 1.1.0. The
flag X509_V_FLAG_CB_ISSUER_CHECK was deprecated in OpenSSL 1.1.0 and
has no effect.
The X509_VERIFY_PARAM_get_hostflags() function was added in OpenSSL
1.1.0i.
The X509_VERIFY_PARAM_get0_host(), X509_VERIFY_PARAM_get0_email(), and
X509_VERIFY_PARAM_get1_ip_asc() functions were added in OpenSSL 3.0.
The function X509_VERIFY_PARAM_add0_policy() was historically
documented as enabling policy checking however the implementation has
never done this. The documentation was changed to align with the
implementation.
COPYRIGHT
Copyright 2009-2023 The OpenSSL Project Authors. All Rights Reserved.
Licensed under the Apache License 2.0 (the "License"). You may not use
this file except in compliance with the License. You can obtain a copy
in the file LICENSE in the source distribution or at
<https://www.openssl.org/source/license.html>.
3.3.2 2024-09-04
X509_VERIFY_PARAM_SET_FLAGS(3ossl)
openssl 3.3.2 - Generated Sun Sep 29 15:58:22 CDT 2024