1 files changed, 149 insertions, 0 deletions
diff --git a/openssl/doc/crypto/OBJ_nid2obj.pod b/openssl/doc/crypto/OBJ_nid2obj.pod
new file mode 100644
index 000000000..7dcc07923
--- /dev/null
+++ b/openssl/doc/crypto/OBJ_nid2obj.pod
@@ -0,0 +1,149 @@
+=pod
+
+=head1 NAME
+
+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
+
+ 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 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);
+ void OBJ_cleanup(void);
+
+=head1 DESCRIPTION
+
+The ASN1 object utility functions process ASN1_OBJECT structures which are
+a representation of the ASN1 OBJECT IDENTIFIER (OID) type.
+
+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> is 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 respresentation 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.
+
+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.
+
+OBJ_cleanup() cleans up OpenSSLs internal object table: this should
+be called before an application exits if any new objects were added
+using OBJ_create().
+
+=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.
+
+=head1 EXAMPLES
+
+Create an object for B<commonName>:
+
+ ASN1_OBJECT *o;
+ 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;
+ ASN1_OBJECT *obj;
+ new_nid = OBJ_create("1.2.3.4", "NewOID", "New Object Identifier");
+
+ 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)|ERR_get_error(3)>
+
+=head1 HISTORY
+
+TBA
+
+=cut