1OBJ_nid2obj(3)                      OpenSSL                     OBJ_nid2obj(3)
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NAME

6       OBJ_nid2obj, OBJ_nid2ln, OBJ_nid2sn, OBJ_obj2nid, OBJ_txt2nid,
7       OBJ_ln2nid, OBJ_sn2nid, OBJ_cmp, OBJ_dup, OBJ_txt2obj, OBJ_obj2txt,
8       OBJ_create, OBJ_cleanup - ASN1 object utility functions
9

SYNOPSIS

11        #include <openssl/objects.h>
12
13        ASN1_OBJECT * OBJ_nid2obj(int n);
14        const char *  OBJ_nid2ln(int n);
15        const char *  OBJ_nid2sn(int n);
16
17        int OBJ_obj2nid(const ASN1_OBJECT *o);
18        int OBJ_ln2nid(const char *ln);
19        int OBJ_sn2nid(const char *sn);
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21        int OBJ_txt2nid(const char *s);
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23        ASN1_OBJECT * OBJ_txt2obj(const char *s, int no_name);
24        int OBJ_obj2txt(char *buf, int buf_len, const ASN1_OBJECT *a, int no_name);
25
26        int OBJ_cmp(const ASN1_OBJECT *a,const ASN1_OBJECT *b);
27        ASN1_OBJECT * OBJ_dup(const ASN1_OBJECT *o);
28
29        int OBJ_create(const char *oid,const char *sn,const char *ln);
30        void OBJ_cleanup(void);
31

DESCRIPTION

33       The ASN1 object utility functions process ASN1_OBJECT structures which
34       are a representation of the ASN1 OBJECT IDENTIFIER (OID) type.
35
36       OBJ_nid2obj(), OBJ_nid2ln() and OBJ_nid2sn() convert the NID n to an
37       ASN1_OBJECT structure, its long name and its short name respectively,
38       or NULL is an error occurred.
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40       OBJ_obj2nid(), OBJ_ln2nid(), OBJ_sn2nid() return the corresponding NID
41       for the object o, the long name <ln> or the short name <sn>
42       respectively or NID_undef if an error occurred.
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44       OBJ_txt2nid() returns NID corresponding to text string <s>. s can be a
45       long name, a short name or the numerical respresentation of an object.
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47       OBJ_txt2obj() converts the text string s into an ASN1_OBJECT structure.
48       If no_name is 0 then long names and short names will be interpreted as
49       well as numerical forms. If no_name is 1 only the numerical form is
50       acceptable.
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52       OBJ_obj2txt() converts the ASN1_OBJECT a into a textual representation.
53       The representation is written as a null terminated string to buf at
54       most buf_len bytes are written, truncating the result if necessary.
55       The total amount of space required is returned. If no_name is 0 then if
56       the object has a long or short name then that will be used, otherwise
57       the numerical form will be used. If no_name is 1 then the numerical
58       form will always be used.
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60       OBJ_cmp() compares a to b. If the two are identical 0 is returned.
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62       OBJ_dup() returns a copy of o.
63
64       OBJ_create() adds a new object to the internal table. oid is the
65       numerical form of the object, sn the short name and ln the long name. A
66       new NID is returned for the created object.
67
68       OBJ_cleanup() cleans up OpenSSLs internal object table: this should be
69       called before an application exits if any new objects were added using
70       OBJ_create().
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NOTES

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 in
76       the header file objects.h.
77
78       For example the OID for commonName has the following definitions:
79
80        #define SN_commonName                   "CN"
81        #define LN_commonName                   "commonName"
82        #define NID_commonName                  13
83
84       New objects can be added by calling OBJ_create().
85
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 also
88       static constant structures which are shared: that is there is only a
89       single constant structure for each table object.
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91       Objects which are not in the table have the NID value NID_undef.
92
93       Objects do not need to be in the internal tables to be processed, the
94       functions OBJ_txt2obj() and OBJ_obj2txt() can process the numerical
95       form of an OID.
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EXAMPLES

98       Create an object for commonName:
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100        ASN1_OBJECT *o;
101        o = OBJ_nid2obj(NID_commonName);
102
103       Check if an object is commonName
104
105        if (OBJ_obj2nid(obj) == NID_commonName)
106               /* Do something */
107
108       Create a new NID and initialize an object from it:
109
110        int new_nid;
111        ASN1_OBJECT *obj;
112        new_nid = OBJ_create("1.2.3.4", "NewOID", "New Object Identifier");
113
114        obj = OBJ_nid2obj(new_nid);
115
116       Create a new object directly:
117
118        obj = OBJ_txt2obj("1.2.3.4", 1);
119

BUGS

121       OBJ_obj2txt() is awkward and messy to use: it doesn't follow the
122       convention of other OpenSSL functions where the buffer can be set to
123       NULL to determine the amount of data that should be written.  Instead
124       buf must point to a valid buffer and buf_len should be set to a
125       positive value. A buffer length of 80 should be more than enough to
126       handle any OID encountered in practice.
127

RETURN VALUES

129       OBJ_nid2obj() returns an ASN1_OBJECT structure or NULL is an error
130       occurred.
131
132       OBJ_nid2ln() and OBJ_nid2sn() returns a valid string or NULL on error.
133
134       OBJ_obj2nid(), OBJ_ln2nid(), OBJ_sn2nid() and OBJ_txt2nid() return a
135       NID or NID_undef on error.
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SEE ALSO

138       ERR_get_error(3)
139

HISTORY

141       TBA
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1451.0.1e                            2013-02-11                    OBJ_nid2obj(3)