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 component separators ('+' for LDAPv3/LDAPv2 or  ','  for  DCE)  and  RDN
       separators (',' 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 values 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
       freeing 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 significant 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  canonical 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 the University of Michigan LDAP 3.3 Release.