.\" $OpenBSD: X509_STORE_CTX_new.3,v 1.26 2021/11/17 16:08:32 schwarze Exp $
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.Dd $Mdocdate: November 17 2021 $
.Dt X509_STORE_CTX_NEW 3
.Os
.Sh NAME
.Nm X509_STORE_CTX_new ,
.Nm X509_STORE_CTX_init ,
.Nm X509_STORE_CTX_cleanup ,
.Nm X509_STORE_CTX_free ,
.Nm X509_STORE_CTX_get0_store ,
.Nm X509_STORE_CTX_set0_trusted_stack ,
.Nm X509_STORE_CTX_trusted_stack ,
.Nm X509_STORE_CTX_set_cert ,
.Nm X509_STORE_CTX_get0_cert ,
.\" X509_STORE_CTX_get0_chain moved to X509_STORE_CTX_get_error(3)
.Nm X509_STORE_CTX_set_chain ,
.Nm X509_STORE_CTX_set0_untrusted ,
.Nm X509_STORE_CTX_get0_untrusted ,
.Nm X509_STORE_CTX_set0_crls
.Nd X509_STORE_CTX initialisation
.Sh SYNOPSIS
.In openssl/x509_vfy.h
.Ft X509_STORE_CTX *
.Fn X509_STORE_CTX_new void
.Ft int
.Fo X509_STORE_CTX_init
.Fa "X509_STORE_CTX *ctx"
.Fa "X509_STORE *store"
.Fa "X509 *x"
.Fa "STACK_OF(X509) *untrusted"
.Fc
.Ft void
.Fo X509_STORE_CTX_cleanup
.Fa "X509_STORE_CTX *ctx"
.Fc
.Ft void
.Fo X509_STORE_CTX_free
.Fa "X509_STORE_CTX *ctx"
.Fc
.Ft X509_STORE *
.Fo X509_STORE_CTX_get0_store
.Fa "X509_STORE_CTX *ctx"
.Fc
.Ft void
.Fo X509_STORE_CTX_set0_trusted_stack
.Fa "X509_STORE_CTX *ctx"
.Fa "STACK_OF(X509) *trusted"
.Fc
.Ft void
.Fo X509_STORE_CTX_trusted_stack
.Fa "X509_STORE_CTX *ctx"
.Fa "STACK_OF(X509) *trusted"
.Fc
.Ft void
.Fo X509_STORE_CTX_set_cert
.Fa "X509_STORE_CTX *ctx"
.Fa "X509 *x"
.Fc
.Ft X509 *
.Fo X509_STORE_CTX_get0_cert
.Fa "X509_STORE_CTX *ctx"
.Fc
.Ft void
.Fo X509_STORE_CTX_set_chain
.Fa "X509_STORE_CTX *ctx"
.Fa "STACK_OF(X509) *untrusted"
.Fc
.Ft void
.Fo X509_STORE_CTX_set0_untrusted
.Fa "X509_STORE_CTX *ctx"
.Fa "STACK_OF(X509) *untrusted"
.Fc
.Ft STACK_OF(X509) *
.Fo X509_STORE_CTX_get0_untrusted
.Fa "X509_STORE_CTX *ctx"
.Fc
.Ft void
.Fo X509_STORE_CTX_set0_crls
.Fa "X509_STORE_CTX *ctx"
.Fa "STACK_OF(X509_CRL) *crls"
.Fc
.Sh DESCRIPTION
These functions set up an
.Vt X509_STORE_CTX
object for subsequent use by
.Xr X509_verify_cert 3 .
.Pp
.Fn X509_STORE_CTX_new
allocates an empty
.Vt X509_STORE_CTX
object not yet containing the subobjects required for normal operation.
.Pp
.Fn X509_STORE_CTX_init
needs to be called on each new
.Fa ctx
before any of the other functions become useful.
It prepares
.Fa ctx
for one single verification operation using
.Xr X509_verify_cert 3 .
The trusted certificate
.Fa store
to be used, the end entity certificate
.Fa x
to be verified, and a set of additional
.Fa untrusted
certificates, to be used for building the chain,
can be supplied, or any or all of them can be set to
.Dv NULL .
The three pointers passed in are stored internally, the three objects
pointed to are not copied, their reference count is not incremented,
and the caller remains responsible for managing their storage and for
not freeing them before
.Fn X509_STORE_CTX_free
is called on
.Fa ctx .
If a
.Fa store
is provided, the verification parameters contained in it are copied using
.Xr X509_VERIFY_PARAM_inherit 3 .
.Pp
.Fn X509_STORE_CTX_cleanup
internally cleans up
.Fa ctx ,
returning it to an empty state similar to the one after
.Fn X509_STORE_CTX_new .
It can then be reused with a new call to
.Fn X509_STORE_CTX_init .
.Pp
.Fn X509_STORE_CTX_free
calls
.Fn X509_STORE_CTX_cleanup
and frees the storage pointed to by
.Fa ctx .
If
.Fa ctx
is a
.Dv NULL
pointer, no action occurs.
.Pp
.Fn X509_STORE_CTX_get0_store
returns the internal pointer to the trusted certificate
.Fa store
that was set with
.Fn X509_STORE_CTX_init .
.Pp
.Fn X509_STORE_CTX_set0_trusted_stack
sets the set of
.Fa trusted
certificates used by
.Fa ctx .
This is an alternative way of specifying trusted certificates instead of
using the
.Fa store .
.Fn X509_STORE_CTX_trusted_stack
is a deprecated alias for
.Fn X509_STORE_CTX_set0_trusted_stack .
.Pp
.Fn X509_STORE_CTX_set_cert
sets the certificate to be verified in
.Fa ctx
to
.Fa x ,
overriding the certificate that was set with
.Fn X509_STORE_CTX_init .
Again, the certificate is not copied
and its reference count is not incremented.
.Pp
.Fn X509_STORE_CTX_get0_cert
retrieves the internal pointer to the certificate being verified by
.Fa ctx ,
i.e. the last one set using either
.Fn X509_STORE_CTX_init
or
.Fn X509_STORE_CTX_set_cert .
.Pp
.Fn X509_STORE_CTX_set_chain
and
.Fn X509_STORE_CTX_set0_untrusted
are identical and set the additional,
.Fa untrusted
certificates used by
.Fa ctx ,
overriding the set of additional, untrusted certificates that was set with
.Fn X509_STORE_CTX_init .
Again, the set and the certificates contained in it are not copied
and their reference counts are not incremented.
.Pp
.Fn X509_STORE_CTX_get0_untrusted
retrieves the internal pointer
to the set of additional, untrusted certificates associated with
.Fa ctx ,
i.e. the last one set using either
.Fn X509_STORE_CTX_init ,
.Fn X509_STORE_CTX_set_chain ,
or
.Fn X509_STORE_CTX_set0_untrusted .
.Pp
.Fn X509_STORE_CTX_set0_crls
sets a set of
.Fa crls
to use during certificate verification.
These CRLs will only be used if CRL verification is enabled in the
associated
.Vt 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.
.Pp
Legacy applications might implicitly use an
.Vt X509_STORE_CTX
like this:
.Bd -literal -offset indent
X509_STORE_CTX ctx;
X509_STORE_CTX_init(&ctx, store, cert, chain);
.Ed
.Pp
This is
.Sy not
recommended in new applications.
They should instead do:
.Bd -literal -offset indent
X509_STORE_CTX *ctx;
ctx = X509_STORE_CTX_new();
if (ctx == NULL)
	/* Bad error */
X509_STORE_CTX_init(ctx, store, cert, chain);
.Ed
.Sh RETURN VALUES
.Fn X509_STORE_CTX_new
returns a newly allocated context or
.Dv NULL
if an error occurred.
.Pp
.Fn X509_STORE_CTX_init
returns 1 for success or 0 if an error occurred.
.Pp
.Fn X509_STORE_CTX_get0_store
returns the internal pointer to the trusted certificate store or
.Dv NULL
if none was set.
.Pp
.Fn X509_STORE_CTX_get0_cert
returns the internal pointer to the certificate to be verified or
.Dv NULL
if no such certificate was set.
.Pp
.Fn X509_STORE_CTX_get0_untrusted
returns the internal pointer
to the set of additional, untrusted certificates or
.Dv NULL
if no set of additional certificates was provided.
.Sh SEE ALSO
.Xr X509_CRL_new 3 ,
.Xr X509_STORE_CTX_get_error 3 ,
.Xr X509_STORE_CTX_get_ex_new_index 3 ,
.Xr X509_STORE_CTX_set_flags 3 ,
.Xr X509_STORE_CTX_set_verify 3 ,
.Xr X509_STORE_CTX_set_verify_cb 3 ,
.Xr X509_STORE_get_by_subject 3 ,
.Xr X509_STORE_new 3 ,
.Xr X509_STORE_set1_param 3 ,
.Xr X509_STORE_set_verify_cb 3 ,
.Xr X509_verify_cert 3 ,
.Xr X509_VERIFY_PARAM_inherit 3 ,
.Xr X509_VERIFY_PARAM_set_flags 3
.Sh HISTORY
.Fn X509_STORE_CTX_init ,
.Fn X509_STORE_CTX_cleanup ,
.Fn X509_STORE_CTX_set_cert ,
and
.Fn X509_STORE_CTX_set_chain
first appeared in SSLeay 0.8.0 and have been available since
.Ox 2.4 .
.Pp
.Fn X509_STORE_CTX_new
and
.Fn X509_STORE_CTX_free
first appeared in OpenSSL 0.9.5 and have been available since
.Ox 2.7 .
.Pp
.Fn X509_STORE_CTX_trusted_stack
first appeared in OpenSSL 0.9.6 and has been available since
.Ox 2.9 .
.Pp
.Fn X509_STORE_CTX_get0_store
first appeared in OpenSSL 1.0.2.
.Fn X509_STORE_CTX_set0_trusted_stack ,
.Fn X509_STORE_CTX_get0_cert ,
.Fn X509_STORE_CTX_set0_untrusted ,
and
.Fn X509_STORE_CTX_get0_untrusted
first appeared in OpenSSL 1.1.0.
These functions have been available since
.Ox 6.3 .