1OBJ_NID2OBJ(3ossl) OpenSSL OBJ_NID2OBJ(3ossl)
2
6 i2t_ASN1_OBJECT, OBJ_length, OBJ_get0_data, OBJ_nid2obj, OBJ_nid2ln,
7 OBJ_nid2sn, OBJ_obj2nid, OBJ_txt2nid, OBJ_ln2nid, OBJ_sn2nid, OBJ_cmp,
8 OBJ_dup, OBJ_txt2obj, OBJ_obj2txt, OBJ_create, OBJ_cleanup,
9 OBJ_add_sigid - ASN1 object utility functions
10
12 #include <openssl/objects.h>
13 ASN1_OBJECT *OBJ_nid2obj(int n);
15 const char *OBJ_nid2ln(int n);
16 const char *OBJ_nid2sn(int n);
17 int OBJ_obj2nid(const ASN1_OBJECT *o);
19 int OBJ_ln2nid(const char *ln);
20 int OBJ_sn2nid(const char *sn);
21 int OBJ_txt2nid(const char *s);
23 ASN1_OBJECT *OBJ_txt2obj(const char *s, int no_name);
25 int OBJ_obj2txt(char *buf, int buf_len, const ASN1_OBJECT *a, int no_name);
26 int i2t_ASN1_OBJECT(char *buf, int buf_len, const ASN1_OBJECT *a);
28 int OBJ_cmp(const ASN1_OBJECT *a, const ASN1_OBJECT *b);
30 ASN1_OBJECT *OBJ_dup(const ASN1_OBJECT *o);
31 int OBJ_create(const char *oid, const char *sn, const char *ln);
33 size_t OBJ_length(const ASN1_OBJECT *obj);
35 const unsigned char *OBJ_get0_data(const ASN1_OBJECT *obj);
36 int OBJ_add_sigid(int signid, int dig_id, int pkey_id);
38 The following function has been deprecated since OpenSSL 1.1.0, and can
40 be hidden entirely by defining OPENSSL_API_COMPAT with a suitable
41 version value, see openssl_user_macros(7):
42 void OBJ_cleanup(void);
44
46 The ASN1 object utility functions process ASN1_OBJECT structures which
47 are a representation of the ASN1 OBJECT IDENTIFIER (OID) type. For
48 convenience, OIDs are usually represented in source code as numeric
49 identifiers, or NIDs. OpenSSL has an internal table of OIDs that are
50 generated when the library is built, and their corresponding NIDs are
51 available as defined constants. For the functions below, application
52 code should treat all returned values -- OIDs, NIDs, or names -- as
53 constants.
54 OBJ_nid2obj(), OBJ_nid2ln() and OBJ_nid2sn() convert the NID n to an
56 ASN1_OBJECT structure, its long name and its short name respectively,
57 or NULL if an error occurred.
58 OBJ_obj2nid(), OBJ_ln2nid(), OBJ_sn2nid() return the corresponding NID
60 for the object o, the long name ln or the short name sn respectively or
61 NID_undef if an error occurred.
62 OBJ_txt2nid() returns NID corresponding to text string s. s can be a
64 long name, a short name or the numerical representation of an object.
65 OBJ_txt2obj() converts the text string s into an ASN1_OBJECT structure.
67 If no_name is 0 then long names and short names will be interpreted as
68 well as numerical forms. If no_name is 1 only the numerical form is
69 acceptable.
70 OBJ_obj2txt() converts the ASN1_OBJECT a into a textual representation.
72 Unless buf is NULL, the representation is written as a NUL-terminated
73 string to buf, where at most buf_len bytes are written, truncating the
74 result if necessary. In any case it returns the total string length,
75 excluding the NUL character, required for non-truncated representation,
76 or -1 on error. If no_name is 0 then if the object has a long or short
77 name then that will be used, otherwise the numerical form will be used.
78 If no_name is 1 then the numerical form will always be used.
79 i2t_ASN1_OBJECT() is the same as OBJ_obj2txt() with the no_name set to
81 zero.
82 OBJ_cmp() compares a to b. If the two are identical 0 is returned.
84 OBJ_dup() returns a copy of o.
86 OBJ_create() adds a new object to the internal table. oid is the
88 numerical form of the object, sn the short name and ln the long name. A
89 new NID is returned for the created object in case of success and
90 NID_undef in case of failure.
91 OBJ_length() returns the size of the content octets of obj.
93 OBJ_get0_data() returns a pointer to the content octets of obj. The
95 returned pointer is an internal pointer which must not be freed.
96 OBJ_add_sigid() creates a new composite "Signature Algorithm" that
98 associates a given NID with two other NIDs - one representing the
99 underlying signature algorithm and the other representing a digest
100 algorithm to be used in conjunction with it. signid represents the NID
101 for the composite "Signature Algorithm", dig_id is the NID for the
102 digest algorithm and pkey_id is the NID for the underlying signature
103 algorithm. As there are signature algorithms that do not require a
104 digest, NID_undef is a valid dig_id.
105 OBJ_cleanup() releases any resources allocated by creating new objects.
107
109 Objects in OpenSSL can have a short name, a long name and a numerical
110 identifier (NID) associated with them. A standard set of objects is
111 represented in an internal table. The appropriate values are defined in
112 the header file objects.h.
113 For example the OID for commonName has the following definitions:
115 #define SN_commonName "CN"
117 #define LN_commonName "commonName"
118 #define NID_commonName 13
119 New objects can be added by calling OBJ_create().
121 Table objects have certain advantages over other objects: for example
123 their NIDs can be used in a C language switch statement. They are also
124 static constant structures which are shared: that is there is only a
125 single constant structure for each table object.
126 Objects which are not in the table have the NID value NID_undef.
128 Objects do not need to be in the internal tables to be processed, the
130 functions OBJ_txt2obj() and OBJ_obj2txt() can process the numerical
131 form of an OID.
132 Some objects are used to represent algorithms which do not have a
134 corresponding ASN.1 OBJECT IDENTIFIER encoding (for example no OID
135 currently exists for a particular algorithm). As a result they cannot
136 be encoded or decoded as part of ASN.1 structures. Applications can
137 determine if there is a corresponding OBJECT IDENTIFIER by checking
138 OBJ_length() is not zero.
139 These functions cannot return const because an ASN1_OBJECT can
141 represent both an internal, constant, OID and a dynamically-created
142 one. The latter cannot be constant because it needs to be freed after
143 use.
144
146 OBJ_nid2obj() returns an ASN1_OBJECT structure or NULL is an error
147 occurred.
148 OBJ_nid2ln() and OBJ_nid2sn() returns a valid string or NULL on error.
150 OBJ_obj2nid(), OBJ_ln2nid(), OBJ_sn2nid() and OBJ_txt2nid() return a
152 NID or NID_undef on error.
153 OBJ_add_sigid() returns 1 on success or 0 on error.
155 i2t_ASN1_OBJECT() an OBJ_obj2txt() return -1 on error. On success,
157 they return the length of the string written to buf if buf is not NULL
158 and buf_len is big enough, otherwise the total string length. Note
159 that this does not count the trailing NUL character.
160
162 Create an object for commonName:
163 ASN1_OBJECT *o = OBJ_nid2obj(NID_commonName);
165 Check if an object is commonName
167 if (OBJ_obj2nid(obj) == NID_commonName)
169 /* Do something */
170 Create a new NID and initialize an object from it:
172 int new_nid = OBJ_create("1.2.3.4", "NewOID", "New Object Identifier");
174 ASN1_OBJECT *obj = OBJ_nid2obj(new_nid);
175 Create a new object directly:
177 obj = OBJ_txt2obj("1.2.3.4", 1);
179
181 Neither OBJ_create() nor OBJ_add_sigid() do any locking and are thus
182 not thread safe. Moreover, none of the other functions should be
183 called while concurrent calls to these two functions are possible.
184
186 ERR_get_error(3)
187
189 OBJ_cleanup() was deprecated in OpenSSL 1.1.0 by OPENSSL_init_crypto(3)
190 and should not be used.
191
193 Copyright 2002-2021 The OpenSSL Project Authors. All Rights Reserved.
194 Licensed under the Apache License 2.0 (the "License"). You may not use
196 this file except in compliance with the License. You can obtain a copy
197 in the file LICENSE in the source distribution or at
198 <https://www.openssl.org/source/license.html>.
1993.0.5 2022-07-05 OBJ_NID2OBJ(3ossl)