X509_ATTRIBUTE_set1_object
,
X509_ATTRIBUTE_set1_data
,
X509_ATTRIBUTE_create_by_OBJ
,
X509_ATTRIBUTE_create_by_NID
,
X509_ATTRIBUTE_create_by_txt
—
modify an X.501 Attribute
#include <openssl/x509.h>
int
X509_ATTRIBUTE_set1_object
(X509_ATTRIBUTE
*attr, const ASN1_OBJECT *obj);
int
X509_ATTRIBUTE_set1_data
(X509_ATTRIBUTE
*attr, int type, const void
*data, int len);
X509_ATTRIBUTE *
X509_ATTRIBUTE_create_by_OBJ
(X509_ATTRIBUTE
**pattr, const ASN1_OBJECT *obj,
int type, const void *data,
int len);
X509_ATTRIBUTE *
X509_ATTRIBUTE_create_by_NID
(X509_ATTRIBUTE
**pattr, int nid, int
type, const void *data, int
len);
X509_ATTRIBUTE *
X509_ATTRIBUTE_create_by_txt
(X509_ATTRIBUTE
**pattr, const char *name, int
type, const unsigned char *data,
int len);
X509_ATTRIBUTE_set1_object
() sets the type of
attr to obj. If
obj is dynamically allocated, a deep copy is created. If
the type of attr was already set, the old type is freed
as far as it was dynamically allocated. After calling this function,
attr may be in an inconsistent state because its values
may not agree with the new attribute type.
X509_ATTRIBUTE_set1_data
() sets
attr to be multi-valued and initializes its set of
values to contain a single new ASN.1 ANY object representing the
data.
The interpretation of the data depends on
the values of the type and len
arguments; there are four different cases.
If the type argument has the bit
MBSTRING_FLAG
set, data is
expected to point to a multibyte character string that is
len bytes long and uses the encoding specified by the
type argument, and it is expected that an attribute
type was already assigned to attr, for example by
calling X509_ATTRIBUTE_set1_object
() before calling
X509_ATTRIBUTE_set1_data
(). In this case, an
appropriate ASN.1 multibyte string type is chosen and a new object of that
type is allocated and populated to represent the data
by calling
ASN1_STRING_set_by_NID(3).
The type of that new ASN.1 string object is subsequently used instead of the
type argument.
If the type argument does not have the bit
MBSTRING_FLAG
set and the len
argument is not -1, the type argument is
expected to be one of the types documented in
ASN1_STRING_new(3)
and data is expected to point to a buffer of
len bytes. In this case, a new object is allocated
with
ASN1_STRING_type_new(3)
and populated with
ASN1_STRING_set(3).
If the type argument does not have the bit
MBSTRING_FLAG
set and the len
argument is -1, data is expected to point to an
object of the given type rather than to a buffer. In
this case, a deep copy of the existing object into the new ASN.1 ANY object
is performed with
ASN1_TYPE_set1(3).
If the type argument is 0, the
data and len arguments are
ignored and the set of values is left empty instead of adding a single ASN.1
ANY object to it. This violates section 8.2 of the X.501 standard, which
requires every attribute to contain at least one value, but some attribute
types used by the library use empty sets of values anyway.
X509_ATTRIBUTE_create_by_OBJ
() sets the
type of **attr to obj using
X509_ATTRIBUTE_set1_object
() and copies the
data into it using
X509_ATTRIBUTE_set1_data
(). If
attr or *attr is
NULL
, a new X509_ATTRIBUTE
object is allocated, populated, and returned.
X509_ATTRIBUTE_create_by_NID
() is a
wrapper around X509_ATTRIBUTE_create_by_OBJ
() that
obtains the required obj argument by calling
OBJ_nid2obj(3)
on the nid argument.
X509_ATTRIBUTE_create_by_txt
() is a
similar wrapper that obtains obj by calling
OBJ_txt2obj(3)
with the arguments name and 0, which means that long
names, short names, and numerical OID strings are all acceptable.
X509_ATTRIBUTE_set1_object
() returns 1 if successful or
0 if attr or obj is
NULL
or if memory allocation fails.
X509_ATTRIBUTE_set1_data
() returns 1 if
successful or 0 if attr is
NULL
or if
ASN1_STRING_set_by_NID(3),
ASN1_STRING_set(3),
ASN1_TYPE_set1(3),
or memory allocation fails.
X509_ATTRIBUTE_create_by_OBJ
(),
X509_ATTRIBUTE_create_by_NID
(), and
X509_ATTRIBUTE_create_by_txt
() return a pointer to
the changed or new object or NULL
if obtaining
obj, allocating memory, or copying fails.
These functions first appeared in OpenSSL 0.9.5 and have been available since
OpenBSD 2.7.
If attr already contains one or more values,
X509_ATTRIBUTE_set1_data
(),
X509_ATTRIBUTE_create_by_OBJ
(),
X509_ATTRIBUTE_create_by_NID
(), and
X509_ATTRIBUTE_create_by_txt
() silently overwrite the
pointers to the old values and leak the memory used for them.