X509_VERIFY_PARAM_set_flags(3) OpenSSL X509_VERIFY_PARAM_set_flags(3)
NAME
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_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
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(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);
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);
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);
char *X509_VERIFY_PARAM_get0_peername(X509_VERIFY_PARAM *param);
int X509_VERIFY_PARAM_set1_email(X509_VERIFY_PARAM *param,
const char *email, size_t emaillen);
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() function sets the flags in param by
oring it with flags. See the VERIFICATION FLAGS section for a complete
description of values the flags parameter can take.
X509_VERIFY_PARAM_get_flags() returns the flags in param.
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 SSL client or SSL server.
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() enables policy checking (it is disabled
by default) and adds policy to the acceptable policy set.
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 untrusted CA certificates that
can appear in a chain.
X509_VERIFY_PARAM_set1_host() sets the expected DNS hostname to name
clearing any previously specified host name or names. 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 are out of scope with the
DANE-EE(3) certificate usage, and the internal check will be suppressed
as appropriate when DANE support is added to OpenSSL.
X509_VERIFY_PARAM_add1_host() adds name as an additional reference
identifer 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_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_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(), X509_VERIFY_PARAM_clear_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_set_hostflags(),
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_get_flags() returns the current verification 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.
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 disabled critical extension checking. By
default any unhandled critical extensions in certificates or (if
checked) CRLs results 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 peformed. 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 ise set delta CRLs (if present) are used to
determine certificate status. If not set deltas are ignored.
X509_V_FLAG_CHECK_SS_SIGNATURE enables checking of the root CA self
signed cerificate signature. 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 root CA signature is that disabled or unsupported message digests
on the root CA are not treated as fatal errors.
The X509_V_FLAG_CB_ISSUER_CHECK flag enables debugging of certificate
issuer checks. It is not needed unless you are logging certificate
verification. If this flag is set then additional status codes will be
sent to the verification callback and it must be prepared to handle
such cases without assuming they are hard errors.
The X509_V_FLAG_NO_ALT_CHAINS flag suppresses checking for alternative
chains. By default, when building a certificate chain, if the first
certificate chain found is not trusted, then OpenSSL will continue to
check to see if an alternative chain can be found that is trusted. With
this flag set the behaviour will match that of OpenSSL versions prior
to 1.0.2b.
NOTES
The above functions should be used to manipulate verification
parameters instead of legacy functions which work in specific
structures such as X509_STORE_CTX_set_flags().
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.
EXAMPLE
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)
HISTORY
The X509_V_FLAG_NO_ALT_CHAINS flag was added in OpenSSL 1.0.2b
1.0.2k 2017-01-26 X509_VERIFY_PARAM_set_flags(3)
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