LDAP_GET_DN(3)		   Library Functions Manual		LDAP_GET_DN(3)



NAME
       ldap_get_dn,  ldap_explode_dn,  ldap_explode_rdn, ldap_dn2ufn - LDAP DN
       handling routines

LIBRARY
       OpenLDAP LDAP (libldap, -lldap)

SYNOPSIS
       #include <ldap.h>

       char *ldap_get_dn( LDAP *ld, LDAPMessage *entry )

       int ldap_str2dn( const char *str, LDAPDN *dn, unsigned flags )

       void ldap_dnfree( LDAPDN dn )

       int ldap_dn2str( LDAPDN dn, char **str, unsigned flags )

       char **ldap_explode_dn( const char *dn, int notypes )

       char **ldap_explode_rdn( const char *rdn, int notypes )

       char *ldap_dn2ufn( const char * dn )

       char *ldap_dn2dcedn( const char * dn )

       char *ldap_dcedn2dn( const char * dn )

       char *ldap_dn2ad_canonical( const char * dn )

DESCRIPTION
       These routines allow LDAP entry names (Distinguished Names, or DNs)  to
       be  obtained, parsed, converted to a user-friendly form, and tested.  A
       DN has the form described in RFC	 4414  "Lightweight  Directory	Access
       Protocol (LDAP): String Representation of Distinguished Names".

       The   ldap_get_dn()   routine   takes   an   entry   as	 returned   by
       ldap_first_entry(3) or ldap_next_entry(3) and returns  a	 copy  of  the
       entry's	DN.   Space for the DN will be obtained dynamically and should
       be freed by the caller using ldap_memfree(3).

       ldap_str2dn() parses a string representation of	a  distinguished  name
       contained  in  str  into	 its  components,  which  are  stored in dn as
       ldap_ava structures, arranged in LDAPAVA, LDAPRDN,  and	LDAPDN	terms.
       Space  for  dn  will be obtained dynamically and should be freed by the
       caller using ldap_dnfree(3).  The LDAPDN is defined as:

       typedef struct ldap_ava {
	   struct berval la_attr;
	   struct berval la_value;
	   unsigned la_flags;
       } LDAPAVA;

       typedef LDAPAVA** LDAPRDN;
       typedef LDAPRDN* LDAPDN;

       The attribute types and the attribute values are not  normalized.   The
       la_flags	 can  be either LDAP_AVA_STRING or LDAP_AVA_BINARY, the latter
       meaning that the value is BER/DER encoded and thus must be  represented
       as, quoting from RFC 4514, " ... an octothorpe character ('#' ASCII 35)
       followed by the hexadecimal representation of each of the bytes of  the
       BER  encoding  of  the  X.500  AttributeValue."	The flags parameter to
       ldap_str2dn() can be

	    LDAP_DN_FORMAT_LDAPV3
	    LDAP_DN_FORMAT_LDAPV2
	    LDAP_DN_FORMAT_DCE

       which defines what DN syntax is expected (according to  RFC  4514,  RFC
       1779 and DCE, respectively).  The format can be ORed to the flags

	    LDAP_DN_P_NO_SPACES
	    LDAP_DN_P_NO_SPACE_AFTER_RDN
	    ...
	    LDAP_DN_PEDANTIC

       The latter is a shortcut for all the previous limitations.

       LDAP_DN_P_NO_SPACES  does not allow extra spaces in the dn; the default
       is to silently eliminate spaces around AVA separators ('='), RDN compo-
       nent  separators ('+' for LDAPv3/LDAPv2 or ',' for DCE) and RDN separa-
       tors (',' LDAPv3/LDAPv2 or '/' for DCE).

       LDAP_DN_P_NO_SPACE_AFTER_RDN does not allow a single  space  after  RDN
       separators.

       ldap_dn2str()  performs the inverse operation, yielding in str a string
       representation  of  dn.	 It  allows  the  same	values	for  flags  as
       ldap_str2dn(), plus

	    LDAP_DN_FORMAT_UFN
	    LDAP_DN_FORMAT_AD_CANONICAL

       for user-friendly naming (RFC 1781) and AD canonical.

       The   following	 routines   are	 viewed	 as  deprecated	 in  favor  of
       ldap_str2dn() and ldap_dn2str().	 They are provided to  support	legacy
       applications.

       The  ldap_explode_dn()  routine takes a DN as returned by ldap_get_dn()
       and breaks it up into its component parts.  Each part  is  known	 as  a
       Relative Distinguished Name, or RDN.  ldap_explode_dn() returns a NULL-
       terminated array, each component of which contains an RDN from the  DN.
       The  notypes  parameter	is used to request that only the RDN values be
       returned, not their types.  For example, the DN	"cn=Bob,  c=US"	 would
       return  as  either { "cn=Bob", "c=US", NULL } or { "Bob", "US", NULL },
       depending on whether notypes was 0 or 1, respectively.  Assertion  val-
       ues  in RDN strings may included escaped characters.  The result can be
       freed by calling ldap_value_free(3).

       Similarly, the ldap_explode_rdn() routine takes an RDN as  returned  by
       ldap_explode_dn(dn,0)  and breaks it up into its "type=value" component
       parts (or just "value", if the notypes parameter	 is  set).   Note  the
       value   is   not	 unescaped.   The  result  can	be  freed  by  calling
       ldap_value_free(3).

       ldap_dn2ufn() is used to turn a DN as returned by ldap_get_dn(3) into a
       more  user-friendly form, stripping off all type names.	See "Using the
       Directory to Achieve User Friendly Naming" (RFC 1781) for more  details
       on  the	UFN  format.  Due to the ambiguous nature of the format, it is
       generally only used for	display	 purposes.   The  space	 for  the  UFN
       returned	 is obtained dynamically and the user is responsible for free-
       ing it via a call to ldap_memfree(3).

       ldap_dn2dcedn() is used to turn a DN as returned by ldap_get_dn(3) into
       a  DCE-style  DN, e.g. a string with most-significant to least signifi-
       cant rdns separated by slashes ('/'); rdn components are	 separated  by
       commas  (',').  Only printable chars (e.g. LDAPv2 printable string) are
       allowed, at least in this implementation.  ldap_dcedn2dn() performs the
       opposite operation.  ldap_dn2ad_canonical() turns a DN into a AD canon-
       ical name, which is basically a DCE dn with  attribute  types  omitted.
       The  trailing  domain, if present, is turned in a DNS-like domain.  The
       space for the returned value is obtained dynamically and	 the  user  is
       responsible for freeing it via a call to ldap_memfree(3).

ERRORS
       If  an error occurs in ldap_get_dn(), NULL is returned and the ld_errno
       field  in  the  ld  parameter  is  set  to  indicate  the  error.   See
       ldap_error(3)	for   a	  description	of   possible	error	codes.
       ldap_explode_dn(), ldap_explode_rdn(), ldap_dn2ufn(),  ldap_dn2dcedn(),
       ldap_dcedn2dn(),	 and  ldap_dn2ad_canonical()  will  return  NULL  with
       errno(3) set appropriately in case of trouble.

NOTES
       These routines dynamically allocate memory that the caller must free.

SEE ALSO
       ldap(3),	   ldap_error(3),    ldap_first_entry(3),     ldap_memfree(3),
       ldap_value_free(3)

ACKNOWLEDGEMENTS
       OpenLDAP	 Software  is developed and maintained by The OpenLDAP Project
       <http://www.openldap.org/>.  OpenLDAP Software is derived from  Univer-
       sity of Michigan LDAP 3.3 Release.



OpenLDAP 2.4.40			  2014/09/20			LDAP_GET_DN(3)