/usr/man/cat.3/X509_NAME_get_index_by_NID.3.Z

NAME

       X509_NAME_get_index_by_NID, X509_NAME_get_index_by_OBJ,
       X509_NAME_get_entry, X509_NAME_entry_count, X509_NAME_get_text_by_NID,
       X509_NAME_get_text_by_OBJ - X509_NAME lookup and enumeration functions

SYNOPSIS

        #include <openssl/x509.h>

        int X509_NAME_get_index_by_NID(X509_NAME *name,int nid,int lastpos);
        int X509_NAME_get_index_by_OBJ(X509_NAME *name,ASN1_OBJECT *obj, int lastpos);

        int X509_NAME_entry_count(X509_NAME *name);
        X509_NAME_ENTRY *X509_NAME_get_entry(X509_NAME *name, int loc);

        int X509_NAME_get_text_by_NID(X509_NAME *name, int nid, char *buf,int len);
        int X509_NAME_get_text_by_OBJ(X509_NAME *name, ASN1_OBJECT *obj, char *buf,int len);

DESCRIPTION

       These functions allow an X509_NAME structure to be examined. The
       X509_NAME structure is the same as the Name type defined in RFC2459
       (and elsewhere) and used for example in certificate subject and issuer
       names.

       X509_NAME_get_index_by_NID() and X509_NAME_get_index_by_OBJ() retrieve
       the next index matching nid or obj after lastpos. lastpos should ini-
       tially be set to -1. If there are no more entries -1 is returned.  If
       nid is invalid (doesn't correspond to a valid OID) then -2 is returned.

       X509_NAME_entry_count() returns the total number of entries in name.

       X509_NAME_get_entry() retrieves the X509_NAME_ENTRY from name corre-
       sponding to index loc. Acceptable values for loc run from 0 to
       (X509_NAME_entry_count(name) - 1). The value returned is an internal
       pointer which must not be freed.

       X509_NAME_get_text_by_NID(), X509_NAME_get_text_by_OBJ() retrieve the
       "text" from the first entry in name which matches nid or obj, if no
       such entry exists -1 is returned. At most len bytes will be written and
       the text written to buf will be null terminated. The length of the out-
       put string written is returned excluding the terminating null. If buf
       is <NULL> then the amount of space needed in buf (excluding the final
       null) is returned.

NOTES

       X509_NAME_get_text_by_NID() and X509_NAME_get_text_by_OBJ() are legacy
       functions which have various limitations which make them of minimal use
       in practice. They can only find the first matching entry and will copy
       the contents of the field verbatim: this can be highly confusing if the
       target is a muticharacter string type like a BMPString or a UTF8String.

       For a more general solution X509_NAME_get_index_by_NID() or
       X509_NAME_get_index_by_OBJ() should be used followed by
       X509_NAME_get_entry() on any matching indices and then the various
       X509_NAME_ENTRY utility functions on the result.

       The list of all relevant NID_* and OBJ_* codes can be found in the
       source code header files <openssl/obj_mac.h> and/or
       <openssl/objects.h>.

       Applications which could pass invalid NIDs to
       X509_NAME_get_index_by_NID() should check for the return value of -2.
       Alternatively the NID validity can be determined first by checking
       OBJ_nid2obj(nid) is not NULL.

EXAMPLES

       Process all entries:

        int i;
        X509_NAME_ENTRY *e;

        for (i = 0; i < X509_NAME_entry_count(nm); i++)
               {
               e = X509_NAME_get_entry(nm, i);
               /* Do something with e */
               }

       Process all commonName entries:

        int lastpos = -1;
        X509_NAME_ENTRY *e;

        for (;;)
               {
               lastpos = X509_NAME_get_index_by_NID(nm, NID_commonName, lastpos);
               if (lastpos == -1)
                       break;
               e = X509_NAME_get_entry(nm, lastpos);
               /* Do something with e */
               }

RETURN VALUES

       X509_NAME_get_index_by_NID() and X509_NAME_get_index_by_OBJ() return
       the index of the next matching entry or -1 if not found.
       X509_NAME_get_index_by_NID() can also return -2 if the supplied NID is
       invalid.

       X509_NAME_entry_count() returns the total number of entries.

       X509_NAME_get_entry() returns an X509_NAME pointer to the requested
       entry or NULL if the index is invalid.

SEE ALSO

       ERR_get_error(3), d2i_X509_NAME(3)

HISTORY

       TBA

1.0.2t                            2019-09-10     X509_NAME_get_index_by_NID(3)
See also X509_NAME_entry_count(3)
See also X509_NAME_get_entry(3)
See also X509_NAME_get_index_by_OBJ(3)
See also X509_NAME_get_text_by_NID(3)
See also X509_NAME_get_text_by_OBJ(3)