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X509_STORE_CTX_NEW(3) OpenSSL X509_STORE_CTX_NEW(3)
NAME
X509_STORE_CTX_new, X509_STORE_CTX_cleanup, X509_STORE_CTX_free,
X509_STORE_CTX_init, X509_STORE_CTX_set0_trusted_stack,
X509_STORE_CTX_set_cert, X509_STORE_CTX_set0_crls,
X509_STORE_CTX_get0_chain, X509_STORE_CTX_set0_verified_chain,
X509_STORE_CTX_get0_param, X509_STORE_CTX_set0_param,
X509_STORE_CTX_get0_untrusted, X509_STORE_CTX_set0_untrusted,
X509_STORE_CTX_get_num_untrusted, X509_STORE_CTX_set_default,
X509_STORE_CTX_set_verify, X509_STORE_CTX_verify_fn,
X509_STORE_CTX_set_purpose, X509_STORE_CTX_set_trust,
X509_STORE_CTX_purpose_inherit - X509_STORE_CTX initialisation
SYNOPSIS
#include <openssl/x509_vfy.h>
X509_STORE_CTX *X509_STORE_CTX_new(void);
void X509_STORE_CTX_cleanup(X509_STORE_CTX *ctx);
void X509_STORE_CTX_free(X509_STORE_CTX *ctx);
int X509_STORE_CTX_init(X509_STORE_CTX *ctx, X509_STORE *store,
X509 *x509, STACK_OF(X509) *chain);
void X509_STORE_CTX_set0_trusted_stack(X509_STORE_CTX *ctx, STACK_OF(X509) *sk);
void X509_STORE_CTX_set_cert(X509_STORE_CTX *ctx, X509 *x);
STACK_OF(X509) *X509_STORE_CTX_get0_chain(X509_STORE_CTX *ctx);
void X509_STORE_CTX_set0_verified_chain(X509_STORE_CTX *ctx, STACK_OF(X509) *chain);
void X509_STORE_CTX_set0_crls(X509_STORE_CTX *ctx, STACK_OF(X509_CRL) *sk);
X509_VERIFY_PARAM *X509_STORE_CTX_get0_param(X509_STORE_CTX *ctx);
void X509_STORE_CTX_set0_param(X509_STORE_CTX *ctx, X509_VERIFY_PARAM *param);
int X509_STORE_CTX_set_default(X509_STORE_CTX *ctx, const char *name);
STACK_OF(X509)* X509_STORE_CTX_get0_untrusted(X509_STORE_CTX *ctx);
void X509_STORE_CTX_set0_untrusted(X509_STORE_CTX *ctx, STACK_OF(X509) *sk);
int X509_STORE_CTX_get_num_untrusted(X509_STORE_CTX *ctx);
typedef int (*X509_STORE_CTX_verify_fn)(X509_STORE_CTX *);
void X509_STORE_CTX_set_verify(X509_STORE_CTX *ctx, X509_STORE_CTX_verify_fn verify);
int X509_STORE_CTX_set_purpose(X509_STORE_CTX *ctx, int purpose);
int X509_STORE_CTX_set_trust(X509_STORE_CTX *ctx, int trust);
int X509_STORE_CTX_purpose_inherit(X509_STORE_CTX *ctx, int def_purpose,
int purpose, int trust);
DESCRIPTION
These functions initialise an X509_STORE_CTX structure for subsequent
use by X509_verify_cert().
X509_STORE_CTX_new() returns a newly initialised X509_STORE_CTX
structure.
X509_STORE_CTX_cleanup() internally cleans up an X509_STORE_CTX
structure. The context can then be reused with a new call to
X509_STORE_CTX_init().
X509_STORE_CTX_free() completely frees up ctx. After this call ctx is
no longer valid. If ctx is NULL nothing is done.
X509_STORE_CTX_init() sets up ctx for a subsequent verification
operation. It must be called before each call to X509_verify_cert(),
i.e. a ctx is only good for one call to X509_verify_cert(); if you want
to verify a second certificate with the same ctx then you must call
X509_STORE_CTX_cleanup() and then X509_STORE_CTX_init() again before
the second call to X509_verify_cert(). The trusted certificate store is
set to store, the end entity certificate to be verified is set to x509
and a set of additional certificates (which will be untrusted but may
be used to build the chain) in chain. Any or all of the store, x509 and
chain parameters can be NULL.
X509_STORE_CTX_set0_trusted_stack() sets the set of trusted
certificates of ctx to sk. This is an alternative way of specifying
trusted certificates instead of using an X509_STORE.
X509_STORE_CTX_set_cert() sets the certificate to be verified in ctx to
x.
X509_STORE_CTX_set0_verified_chain() sets the validated chain used by
ctx to be chain. Ownership of the chain is transferred to ctx and
should not be free'd by the caller. X509_STORE_CTX_get0_chain()
returns the internal pointer used by the ctx that contains the
validated chain.
X509_STORE_CTX_set0_crls() sets a set of CRLs to use to aid certificate
verification to sk. These CRLs will only be used if CRL verification is
enabled in the associated X509_VERIFY_PARAM structure. This might be
used where additional "useful" CRLs are supplied as part of a protocol,
for example in a PKCS#7 structure.
X509_STORE_CTX_get0_param() retrieves an internal pointer to the
verification parameters associated with ctx.
X509_STORE_CTX_get0_untrusted() retrieves an internal pointer to the
stack of untrusted certificates associated with ctx.
X509_STORE_CTX_set0_untrusted() sets the internal point to the stack of
untrusted certificates associated with ctx to sk.
X509_STORE_CTX_set0_param() sets the internal verification parameter
pointer to param. After this call param should not be used.
X509_STORE_CTX_set_default() looks up and sets the default verification
method to name. This uses the function X509_VERIFY_PARAM_lookup() to
find an appropriate set of parameters from name.
X509_STORE_CTX_get_num_untrusted() returns the number of untrusted
certificates that were used in building the chain following a call to
X509_verify_cert().
X509_STORE_CTX_set_verify() provides the capability for overriding the
default verify function. This function is responsible for verifying
chain signatures and expiration times.
A verify function is defined as an X509_STORE_CTX_verify type which has
the following signature:
int (*verify)(X509_STORE_CTX *);
This function should receive the current X509_STORE_CTX as a parameter
and return 1 on success or 0 on failure.
X509 certificates may contain information about what purposes keys
contained within them can be used for. For example "TLS WWW Server
Authentication" or "Email Protection". This "key usage" information is
held internally to the certificate itself. In addition the trust store
containing trusted certificates can declare what purposes we trust
different certificates for. This "trust" information is not held within
the certificate itself but is "meta" information held alongside it.
This "meta" information is associated with the certificate after it is
issued and could be determined by a system administrator. For example a
certificate might declare that it is suitable for use for both "TLS WWW
Server Authentication" and "TLS Client Authentication", but a system
administrator might only trust it for the former. An X.509 certificate
extension exists that can record extended key usage information to
supplement the purpose information described above. This extended
mechanism is arbitrarily extensible and not well suited for a generic
library API; applications that need to validate extended key usage
information in certifiates will need to define a custom "purpose" (see
below) or supply a nondefault verification callback
(X509_STORE_set_verify_cb_func(3)).
X509_STORE_CTX_set_purpose() sets the purpose for the target
certificate being verified in the ctx. Built-in available values for
the purpose argument are X509_PURPOSE_SSL_CLIENT,
X509_PURPOSE_SSL_SERVER, X509_PURPOSE_NS_SSL_SERVER,
X509_PURPOSE_SMIME_SIGN, X509_PURPOSE_SMIME_ENCRYPT,
X509_PURPOSE_CRL_SIGN, X509_PURPOSE_ANY, X509_PURPOSE_OCSP_HELPER and
X509_PURPOSE_TIMESTAMP_SIGN. It is also possible to create a custom
purpose value. Setting a purpose will ensure that the key usage
declared within certificates in the chain being verified is consistent
with that purpose as well as, potentially, other checks. Every purpose
also has an associated default trust value which will also be set at
the same time. During verification this trust setting will be verified
to check it is consistent with the trust set by the system
administrator for certificates in the chain.
X509_STORE_CTX_set_trust() sets the trust value for the target
certificate being verified in the ctx. Built-in available values for
the trust argument are X509_TRUST_COMPAT, X509_TRUST_SSL_CLIENT,
X509_TRUST_SSL_SERVER, X509_TRUST_EMAIL, X509_TRUST_OBJECT_SIGN,
X509_TRUST_OCSP_SIGN, X509_TRUST_OCSP_REQUEST and X509_TRUST_TSA. It is
also possible to create a custom trust value. Since
X509_STORE_CTX_set_purpose() also sets the trust value it is normally
sufficient to only call that function. If both are called then
X509_STORE_CTX_set_trust() should be called after
X509_STORE_CTX_set_purpose() since the trust setting of the last call
will be used.
It should not normally be necessary for end user applications to call
X509_STORE_CTX_purpose_inherit() directly. Typically applications
should call X509_STORE_CTX_set_purpose() or X509_STORE_CTX_set_trust()
instead. Using this function it is possible to set the purpose and
trust values for the ctx at the same time. Both ctx and its internal
verification parameter pointer must not be NULL. The def_purpose and
purpose arguments can have the same purpose values as described for
X509_STORE_CTX_set_purpose() above. The trust argument can have the
same trust values as described in X509_STORE_CTX_set_trust() above. Any
of the def_purpose, purpose or trust values may also have the value 0
to indicate that the supplied parameter should be ignored. After
calling this function the purpose to be used for verification is set
from the purpose argument unless the purpose was already set in ctx
before, and the trust is set from the trust argument unless the trust
was already set in ctx before. If trust is 0 then the trust value will
be set from the default trust value for purpose. If the default trust
value for the purpose is X509_TRUST_DEFAULT and trust is 0 then the
default trust value associated with the def_purpose value is used for
the trust setting instead.
NOTES
The certificates and CRLs in a store are used internally and should not
be freed up until after the associated X509_STORE_CTX is freed.
BUGS
The certificates and CRLs in a context are used internally and should
not be freed up until after the associated X509_STORE_CTX is freed.
Copies should be made or reference counts increased instead.
RETURN VALUES
X509_STORE_CTX_new() returns a newly allocated context or NULL if an
error occurred.
X509_STORE_CTX_init() returns 1 for success or 0 if an error occurred.
X509_STORE_CTX_get0_param() returns a pointer to an X509_VERIFY_PARAM
structure or NULL if an error occurred.
X509_STORE_CTX_cleanup(), X509_STORE_CTX_free(),
X509_STORE_CTX_set0_trusted_stack(), X509_STORE_CTX_set_cert(),
X509_STORE_CTX_set0_crls() and X509_STORE_CTX_set0_param() do not
return values.
X509_STORE_CTX_set_default() returns 1 for success or 0 if an error
occurred.
X509_STORE_CTX_get_num_untrusted() returns the number of untrusted
certificates used.
SEE ALSO
X509_verify_cert(3) X509_VERIFY_PARAM_set_flags(3)
HISTORY
The X509_STORE_CTX_set0_crls() function was added in OpenSSL 1.0.0.
The X509_STORE_CTX_get_num_untrusted() function was added in OpenSSL
1.1.0.
COPYRIGHT
Copyright 2009-2022 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
<https://www.openssl.org/source/license.html>.
1.1.1v 2023-08-01 X509_STORE_CTX_NEW(3)