ASN1_TYPE_get, ASN1_TYPE_set, ASN1_TYPE_set1, ASN1_TYPE_cmp,
ASN1_TYPE_unpack_sequence, ASN1_TYPE_pack_sequence - ASN1_TYPE utility
functions
#include <openssl/asn1.h>
int ASN1_TYPE_get(const ASN1_TYPE *a);
void ASN1_TYPE_set(ASN1_TYPE *a, int type, void *value);
int ASN1_TYPE_set1(ASN1_TYPE *a, int type, const void *value);
int ASN1_TYPE_cmp(const ASN1_TYPE *a, const ASN1_TYPE *b);
void *ASN1_TYPE_unpack_sequence(const ASN1_ITEM *it, const ASN1_TYPE *t);
ASN1_TYPE *ASN1_TYPE_pack_sequence(const ASN1_ITEM *it, void *s,
ASN1_TYPE **t);
These functions allow an
ASN1_TYPE structure to be manipulated. The
ASN1_TYPE structure can contain any ASN.1 type or constructed type such
as a SEQUENCE: it is effectively equivalent to the ASN.1 ANY type.
ASN1_TYPE_get() returns the type of
a or 0 if it fails.
ASN1_TYPE_set() sets the value of
a to
type and
value. This function uses the pointer
value internally so it
must
not be freed up after the call.
ASN1_TYPE_set1() sets the value of
a to
type a copy of
value.
ASN1_TYPE_cmp() compares ASN.1 types
a and
b and returns 0
if they are identical and nonzero otherwise.
ASN1_TYPE_unpack_sequence() attempts to parse the SEQUENCE present in
t using the ASN.1 structure
it. If successful it returns a
pointer to the ASN.1 structure corresponding to
it which must be freed
by the caller. If it fails it return NULL.
ASN1_TYPE_pack_sequence() attempts to encode the ASN.1 structure
s
corresponding to
it into an
ASN1_TYPE. If successful the encoded
ASN1_TYPE is returned. If
t and
*t are not NULL the
encoded type is written to
t overwriting any existing data. If
t
is not NULL but
*t is NULL the returned
ASN1_TYPE is written to
*t.
The type and meaning of the
value parameter for
ASN1_TYPE_set()
and
ASN1_TYPE_set1() is determined by the
type parameter. If
type is
V_ASN1_NULL value is ignored. If
type is
V_ASN1_BOOLEAN then the boolean is set to TRUE if
value is not
NULL. If
type is
V_ASN1_OBJECT then value is an
ASN1_OBJECT structure. Otherwise
type is and
ASN1_STRING
structure. If
type corresponds to a primitive type (or a string type)
then the contents of the
ASN1_STRING contain the content octets of the
type. If
type corresponds to a constructed type or a tagged type (
V_ASN1_SEQUENCE,
V_ASN1_SET or
V_ASN1_OTHER) then the
ASN1_STRING contains the entire ASN.1 encoding verbatim (including tag
and length octets).
ASN1_TYPE_cmp() may not return zero if two types are equivalent but have
different encodings. For example the single content octet of the boolean TRUE
value under BER can have any nonzero encoding but
ASN1_TYPE_cmp() will
only return zero if the values are the same.
If either or both of the parameters passed to
ASN1_TYPE_cmp() is NULL the
return value is nonzero. Technically if both parameters are NULL the two types
could be absent OPTIONAL fields and so should match, however, passing NULL
values could also indicate a programming error (for example an unparsable type
which returns NULL) for types which do
not match. So applications
should handle the case of two absent values separately.
ASN1_TYPE_get() returns the type of the
ASN1_TYPE argument.
ASN1_TYPE_set() does not return a value.
ASN1_TYPE_set1() returns 1 for success and 0 for failure.
ASN1_TYPE_cmp() returns 0 if the types are identical and nonzero
otherwise.
ASN1_TYPE_unpack_sequence() returns a pointer to an ASN.1 structure or
NULL on failure.
ASN1_TYPE_pack_sequence() return an
ASN1_TYPE structure if it
succeeds or NULL on failure.
Copyright 2015-2021 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>.