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       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_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_set1_email, X509_VERIFY_PARAM_set1_ip,
       X509_VERIFY_PARAM_set1_ip_asc - X509 verification parameters

	#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_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);

	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(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);

       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_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 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 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

       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_set1_host() sets the expected DNS hostname to name
       clearing	any previously specified hostname 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 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_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_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_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.

       X509_VERIFY_PARAM_set_flags(), 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_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

       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.

       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 performed.	Additional information is sent
       to the verification callback relating to	policy checking.

       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, construction of the certificate
       chain in	X509_verify_cert(3) will search	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	x509(1)).  As of
       OpenSSL 1.1.0 this option is on by default.

       The X509_V_FLAG_NO_ALT_CHAINS flag suppresses 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 intermediate certificates in
       the trust store to be treated as	trust-anchors, in the same way as the
       self-signed root	CA certificates.  This makes it	possible to trust
       certificates issued by an intermediate CA without having	to trust its
       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 from the trust store is added to the chain,
       whether that certificate	is a self-signed "root"	certificate or a not
       self-signed intermediate	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.

       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.

       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.

       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.

       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_cert(3), X509_check_host(3),	X509_check_email(3),
       X509_check_ip(3), x509(1)

       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

       Copyright 2009-2020 The OpenSSL Project Authors.	All Rights Reserved.

       Licensed	under the OpenSSL license (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

1.1.1o				  2022-05-03	X509_VERIFY_PARAM_SET_FLAGS(3)


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