#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);
#if OPENSSL_API_COMPAT < 0x10100000L void OBJ_cleanup(void) #endif
OBJ_nid2obj(), OBJ_nid2ln() and OBJ_nid2sn() convert the NID n to an ASN1_OBJECT structure, its long name and its short name respectively, or NULL if an error occurred.
OBJ_obj2nid(), OBJ_ln2nid(), OBJ_sn2nid() return the corresponding NID for the object 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>. s can be a long name, a short name or the numerical representation of an object.
OBJ_txt2obj() converts the text string s into an ASN1_OBJECT structure. If no_name is 0 then long names and short names will be interpreted as well as numerical forms. If no_name is 1 only the numerical form is acceptable.
OBJ_obj2txt() converts the ASN1_OBJECT a into a textual representation. The representation is written as a null terminated string to buf at most buf_len bytes are written, truncating the result if necessary. The total amount of space required is returned. If 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 no_name is 1 then the numerical form will always be used.
i2t_ASN1_OBJECT() is the same as OBJ_obj2txt() with the no_name set to zero.
OBJ_cmp() compares a to b. If the two are identical 0 is returned.
OBJ_dup() returns a copy of o.
OBJ_create() adds a new object to the internal table. oid is the numerical form of the object, sn the short name and 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 obj.
OBJ_get0_data() returns a pointer to the content octets of obj. The returned pointer is an internal pointer which must not be freed.
OBJ_cleanup() releases any resources allocated by creating new objects.
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 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 const because an 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.
OBJ_nid2ln() and OBJ_nid2sn() returns a valid string or NULL on error.
OBJ_obj2nid(), OBJ_ln2nid(), OBJ_sn2nid() and OBJ_txt2nid() return a NID or NID_undef on error.
ASN1_OBJECT *o = OBJ_nid2obj(NID_commonName);
Check if an object is commonName
if (OBJ_obj2nid(obj) == NID_commonName) /* Do something */
Create a new NID and initialize an object from it:
int new_nid = OBJ_create("188.8.131.52", "NewOID", "New Object Identifier"); ASN1_OBJECT *obj = OBJ_nid2obj(new_nid);
Create a new object directly:
obj = OBJ_txt2obj("184.108.40.206", 1);
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 https://www.openssl.org/source/license.html.