NAME | LIBRARY | SYNOPSIS | DESCRIPTION | ERRORS | NOTES | SEE ALSO | ACKNOWLEDGEMENTS | COLOPHON

LDAP_GET_DN(3)            Library Functions Manual            LDAP_GET_DN(3)

NAME         top

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

LIBRARY         top

       OpenLDAP LDAP (libldap, -lldap)

SYNOPSIS         top

       #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         top

       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         top

       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         top

       These routines dynamically allocate memory that the caller must free.

SEE ALSO         top

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

ACKNOWLEDGEMENTS         top

       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.

COLOPHON         top

       This page is part of the OpenLDAP (an open source implementation of
       the Lightweight Directory Access Protocol) project.  Information
       about the project can be found at ⟨http://www.openldap.org/⟩.  If you
       have a bug report for this manual page, see 
       ⟨http://www.openldap.org/its/⟩.  This page was obtained from the
       project's upstream Git repository 
       ⟨git://git.openldap.org/openldap.git⟩ on 2017-09-15.  If you discover
       any rendering problems in this HTML version of the page, or you
       believe there is a better or more up-to-date source for the page, or
       you have corrections or improvements to the information in this
       COLOPHON (which is not part of the original manual page), send a mail
       to man-pages@man7.org

OpenLDAP LDVERSION               RELEASEDATE                  LDAP_GET_DN(3)

Pages that refer to this page: ldap_first_entry(3)ldap_get_dn(3)ldap_sync(3)