5 OBJ_nid2obj, OBJ_nid2ln, OBJ_nid2sn, OBJ_obj2nid, OBJ_txt2nid, OBJ_ln2nid, OBJ_sn2nid,
6 OBJ_cmp, OBJ_dup, OBJ_txt2obj, OBJ_obj2txt, OBJ_create, OBJ_cleanup - ASN1 object utility
11 ASN1_OBJECT * OBJ_nid2obj(int n);
12 const char * OBJ_nid2ln(int n);
13 const char * OBJ_nid2sn(int n);
15 int OBJ_obj2nid(const ASN1_OBJECT *o);
16 int OBJ_ln2nid(const char *ln);
17 int OBJ_sn2nid(const char *sn);
19 int OBJ_txt2nid(const char *s);
21 ASN1_OBJECT * OBJ_txt2obj(const char *s, int no_name);
22 int OBJ_obj2txt(char *buf, int buf_len, const ASN1_OBJECT *a, int no_name);
24 int OBJ_cmp(const ASN1_OBJECT *a,const ASN1_OBJECT *b);
25 ASN1_OBJECT * OBJ_dup(const ASN1_OBJECT *o);
27 int OBJ_create(const char *oid,const char *sn,const char *ln);
28 void OBJ_cleanup(void);
32 The ASN1 object utility functions process ASN1_OBJECT structures which are
33 a representation of the ASN1 OBJECT IDENTIFIER (OID) type.
35 OBJ_nid2obj(), OBJ_nid2ln() and OBJ_nid2sn() convert the NID B<n> to
36 an ASN1_OBJECT structure, its long name and its short name respectively,
37 or B<NULL> is an error occurred.
39 OBJ_obj2nid(), OBJ_ln2nid(), OBJ_sn2nid() return the corresponding NID
40 for the object B<o>, the long name <ln> or the short name <sn> respectively
41 or NID_undef if an error occurred.
43 OBJ_txt2nid() returns NID corresponding to text string <s>. B<s> can be
44 a long name, a short name or the numerical respresentation of an object.
46 OBJ_txt2obj() converts the text string B<s> into an ASN1_OBJECT structure.
47 If B<no_name> is 0 then long names and short names will be interpreted
48 as well as numerical forms. If B<no_name> is 1 only the numerical form
51 OBJ_obj2txt() converts the B<ASN1_OBJECT> B<a> into a textual representation.
52 The representation is written as a null terminated string to B<buf>
53 at most B<buf_len> bytes are written, truncating the result if necessary.
54 The total amount of space required is returned. If B<no_name> is 0 then
55 if the object has a long or short name then that will be used, otherwise
56 the numerical form will be used. If B<no_name> is 1 then the numerical
57 form will always be used.
59 OBJ_cmp() compares B<a> to B<b>. If the two are identical 0 is returned.
61 OBJ_dup() returns a copy of B<o>.
63 OBJ_create() adds a new object to the internal table. B<oid> is the
64 numerical form of the object, B<sn> the short name and B<ln> the
65 long name. A new NID is returned for the created object.
67 OBJ_cleanup() cleans up OpenSSLs internal object table: this should
68 be called before an application exits if any new objects were added
73 Objects in OpenSSL can have a short name, a long name and a numerical
74 identifier (NID) associated with them. A standard set of objects is
75 represented in an internal table. The appropriate values are defined
76 in the header file B<objects.h>.
78 For example the OID for commonName has the following definitions:
80 #define SN_commonName "CN"
81 #define LN_commonName "commonName"
82 #define NID_commonName 13
84 New objects can be added by calling OBJ_create().
86 Table objects have certain advantages over other objects: for example
87 their NIDs can be used in a C language switch statement. They are
88 also static constant structures which are shared: that is there
89 is only a single constant structure for each table object.
91 Objects which are not in the table have the NID value NID_undef.
93 Objects do not need to be in the internal tables to be processed,
94 the functions OBJ_txt2obj() and OBJ_obj2txt() can process the numerical
99 Create an object for B<commonName>:
102 o = OBJ_nid2obj(NID_commonName);
104 Check is an object is B<commonName>
106 if (OBJ_obj2nid(obj) == NID_commonName)
109 Create a new NID and initialize an object from it:
113 new_nid = OBJ_create("1.2.3.4", "NewOID", "New Object Identifier");
115 obj = OBJ_nid2obj(new_nid);
117 Create a new object directly:
119 obj = OBJ_txt2obj("1.2.3.4", 1);
123 OBJ_obj2txt() is awkward and messy to use: it doesn't follow the
124 convention of other OpenSSL functions where the buffer can be set
125 to B<NULL> to determine the amount of data that should be written.
126 Instead B<buf> must point to a valid buffer and B<buf_len> should
127 be set to a positive value. A buffer length of 80 should be more
128 than enough to handle any OID encountered in practice.
132 OBJ_nid2obj() returns an ASN1_OBJECT structure or B<NULL> is an
135 OBJ_nid2ln() and OBJ_nid2sn() returns a valid string or B<NULL>
138 OBJ_obj2nid(), OBJ_ln2nid(), OBJ_sn2nid() and OBJ_txt2nid() return
139 a NID or NID_undef on error.
143 L<ERR_get_error(3)|ERR_get_error(3)>