2d162ea93f
Reviewed-by: Kurt Roeckx <kurt@roeckx.be> Reviewed-by: Richard Levitte <levitte@openssl.org> (Merged from https://github.com/openssl/openssl/pull/6998)
191 lines
6.6 KiB
Text
191 lines
6.6 KiB
Text
=pod
|
|
|
|
=head1 NAME
|
|
|
|
i2t_ASN1_OBJECT,
|
|
OBJ_length, OBJ_get0_data, OBJ_nid2obj, OBJ_nid2ln,
|
|
OBJ_nid2sn, OBJ_obj2nid, OBJ_txt2nid, OBJ_ln2nid, OBJ_sn2nid, OBJ_cmp,
|
|
OBJ_dup, OBJ_txt2obj, OBJ_obj2txt, OBJ_create, OBJ_cleanup
|
|
- ASN1 object utility functions
|
|
|
|
=head1 SYNOPSIS
|
|
|
|
#include <openssl/objects.h>
|
|
|
|
ASN1_OBJECT *OBJ_nid2obj(int n);
|
|
const char *OBJ_nid2ln(int n);
|
|
const char *OBJ_nid2sn(int n);
|
|
|
|
int OBJ_obj2nid(const ASN1_OBJECT *o);
|
|
int OBJ_ln2nid(const char *ln);
|
|
int OBJ_sn2nid(const char *sn);
|
|
|
|
int OBJ_txt2nid(const char *s);
|
|
|
|
ASN1_OBJECT *OBJ_txt2obj(const char *s, int no_name);
|
|
int OBJ_obj2txt(char *buf, int buf_len, const ASN1_OBJECT *a, int no_name);
|
|
|
|
int i2t_ASN1_OBJECT(char *buf, int buf_len, const ASN1_OBJECT *a);
|
|
|
|
int OBJ_cmp(const ASN1_OBJECT *a, const ASN1_OBJECT *b);
|
|
ASN1_OBJECT *OBJ_dup(const ASN1_OBJECT *o);
|
|
|
|
int OBJ_create(const char *oid, const char *sn, const char *ln);
|
|
|
|
size_t OBJ_length(const ASN1_OBJECT *obj);
|
|
const unsigned char *OBJ_get0_data(const ASN1_OBJECT *obj);
|
|
|
|
Deprecated:
|
|
|
|
#if OPENSSL_API_COMPAT < 0x10100000L
|
|
void OBJ_cleanup(void)
|
|
#endif
|
|
|
|
=head1 DESCRIPTION
|
|
|
|
The ASN1 object utility functions process ASN1_OBJECT structures which are
|
|
a representation of the ASN1 OBJECT IDENTIFIER (OID) type.
|
|
For convenience, OIDs are usually represented in source code as numeric
|
|
identifiers, or B<NID>s. OpenSSL has an internal table of OIDs that
|
|
are generated when the library is built, and their corresponding NIDs
|
|
are available as defined constants. For the functions below, application
|
|
code should treat all returned values -- OIDs, NIDs, or names -- as
|
|
constants.
|
|
|
|
OBJ_nid2obj(), OBJ_nid2ln() and OBJ_nid2sn() convert the NID B<n> to
|
|
an ASN1_OBJECT structure, its long name and its short name respectively,
|
|
or B<NULL> if an error occurred.
|
|
|
|
OBJ_obj2nid(), OBJ_ln2nid(), OBJ_sn2nid() return the corresponding NID
|
|
for the object B<o>, the long name <ln> or the short name <sn> respectively
|
|
or NID_undef if an error occurred.
|
|
|
|
OBJ_txt2nid() returns NID corresponding to text string <s>. B<s> can be
|
|
a long name, a short name or the numerical representation of an object.
|
|
|
|
OBJ_txt2obj() converts the text string B<s> into an ASN1_OBJECT structure.
|
|
If B<no_name> is 0 then long names and short names will be interpreted
|
|
as well as numerical forms. If B<no_name> is 1 only the numerical form
|
|
is acceptable.
|
|
|
|
OBJ_obj2txt() converts the B<ASN1_OBJECT> B<a> into a textual representation.
|
|
The representation is written as a null terminated string to B<buf>
|
|
at most B<buf_len> bytes are written, truncating the result if necessary.
|
|
The total amount of space required is returned. If B<no_name> is 0 then
|
|
if the object has a long or short name then that will be used, otherwise
|
|
the numerical form will be used. If B<no_name> is 1 then the numerical
|
|
form will always be used.
|
|
|
|
i2t_ASN1_OBJECT() is the same as OBJ_obj2txt() with the B<no_name> set to zero.
|
|
|
|
OBJ_cmp() compares B<a> to B<b>. If the two are identical 0 is returned.
|
|
|
|
OBJ_dup() returns a copy of B<o>.
|
|
|
|
OBJ_create() adds a new object to the internal table. B<oid> is the
|
|
numerical form of the object, B<sn> the short name and B<ln> the
|
|
long name. A new NID is returned for the created object in case of
|
|
success and NID_undef in case of failure.
|
|
|
|
OBJ_length() returns the size of the content octets of B<obj>.
|
|
|
|
OBJ_get0_data() returns a pointer to the content octets of B<obj>.
|
|
The returned pointer is an internal pointer which B<must not> be freed.
|
|
|
|
OBJ_cleanup() releases any resources allocated by creating new objects.
|
|
|
|
=head1 NOTES
|
|
|
|
Objects in OpenSSL can have a short name, a long name and a numerical
|
|
identifier (NID) associated with them. A standard set of objects is
|
|
represented in an internal table. The appropriate values are defined
|
|
in the header file B<objects.h>.
|
|
|
|
For example the OID for commonName has the following definitions:
|
|
|
|
#define SN_commonName "CN"
|
|
#define LN_commonName "commonName"
|
|
#define NID_commonName 13
|
|
|
|
New objects can be added by calling OBJ_create().
|
|
|
|
Table objects have certain advantages over other objects: for example
|
|
their NIDs can be used in a C language switch statement. They are
|
|
also static constant structures which are shared: that is there
|
|
is only a single constant structure for each table object.
|
|
|
|
Objects which are not in the table have the NID value NID_undef.
|
|
|
|
Objects do not need to be in the internal tables to be processed,
|
|
the functions OBJ_txt2obj() and OBJ_obj2txt() can process the numerical
|
|
form of an OID.
|
|
|
|
Some objects are used to represent algorithms which do not have a
|
|
corresponding ASN.1 OBJECT IDENTIFIER encoding (for example no OID currently
|
|
exists for a particular algorithm). As a result they B<cannot> be encoded or
|
|
decoded as part of ASN.1 structures. Applications can determine if there
|
|
is a corresponding OBJECT IDENTIFIER by checking OBJ_length() is not zero.
|
|
|
|
These functions cannot return B<const> because an B<ASN1_OBJECT> can
|
|
represent both an internal, constant, OID and a dynamically-created one.
|
|
The latter cannot be constant because it needs to be freed after use.
|
|
|
|
=head1 EXAMPLES
|
|
|
|
Create an object for B<commonName>:
|
|
|
|
ASN1_OBJECT *o = OBJ_nid2obj(NID_commonName);
|
|
|
|
Check if an object is B<commonName>
|
|
|
|
if (OBJ_obj2nid(obj) == NID_commonName)
|
|
/* Do something */
|
|
|
|
Create a new NID and initialize an object from it:
|
|
|
|
int new_nid = OBJ_create("1.2.3.4", "NewOID", "New Object Identifier");
|
|
ASN1_OBJECT *obj = OBJ_nid2obj(new_nid);
|
|
|
|
Create a new object directly:
|
|
|
|
obj = OBJ_txt2obj("1.2.3.4", 1);
|
|
|
|
=head1 BUGS
|
|
|
|
OBJ_obj2txt() is awkward and messy to use: it doesn't follow the
|
|
convention of other OpenSSL functions where the buffer can be set
|
|
to B<NULL> to determine the amount of data that should be written.
|
|
Instead B<buf> must point to a valid buffer and B<buf_len> should
|
|
be set to a positive value. A buffer length of 80 should be more
|
|
than enough to handle any OID encountered in practice.
|
|
|
|
=head1 RETURN VALUES
|
|
|
|
OBJ_nid2obj() returns an B<ASN1_OBJECT> structure or B<NULL> is an
|
|
error occurred.
|
|
|
|
OBJ_nid2ln() and OBJ_nid2sn() returns a valid string or B<NULL>
|
|
on error.
|
|
|
|
OBJ_obj2nid(), OBJ_ln2nid(), OBJ_sn2nid() and OBJ_txt2nid() return
|
|
a NID or B<NID_undef> on error.
|
|
|
|
=head1 SEE ALSO
|
|
|
|
L<ERR_get_error(3)>
|
|
|
|
=head1 HISTORY
|
|
|
|
OBJ_cleanup() was deprecated in OpenSSL 1.1.0 by L<OPENSSL_init_crypto(3)>
|
|
and should not be used.
|
|
|
|
=head1 COPYRIGHT
|
|
|
|
Copyright 2002-2018 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
|
|
L<https://www.openssl.org/source/license.html>.
|
|
|
|
=cut
|