ldap_start_tls_sA function (winldap.h)

The ldap_start_tls_s function is used in an active LDAP session to begin using TLS encryption.

Syntax

WINLDAPAPI ULONG LDAPAPI ldap_start_tls_sA(
  PLDAP         ExternalHandle,
  PULONG        ServerReturnValue,
  LDAPMessage   **result,
  PLDAPControlA *ServerControls,
  PLDAPControlA *ClientControls
);

Parameters

ExternalHandle

A pointer to an LDAP structure that represents the current session.

ServerReturnValue

Optional. A pointer to a ULONG that may contain a server error code. This parameter should be consulted if LDAP_OTHER is returned in the return value. Pass in NULL if you do not wish to use it.

result

Optional. A pointer to a pointer for an LDAPMessage structure that may contain a server referral message. Pass in NULL if you do not wish to use it.

ServerControls

Optional. A NULL-terminated array of pointers to LDAPControl structures that represent server controls. Pass in NULL if you do not want to specify server controls.

ClientControls

Optional. A NULL-terminated array of pointers to LDAPControl structures that represent client controls. Pass in NULL if you do not want to specify client controls.

Return value

If the function call succeeds, LDAP_SUCCESS is returned. LDAP_UNWILLING_TO_PERFORM is returned if a TLD/SSL session is already in progress, or if a bind is currently in progress, or if there is an outstanding LDAP request on the connection. If the server rejects the extended operation, LDAP_OTHER is returned and the ServerReturnValue parameter should be checked for the server error code.

Remarks

The ldap_start_tls_s function is called on an existing LDAP session to initiate the use of TLS (SSL) encryption. The connection must not already have TLS (SSL) encryption enabled, and neither signing nor sealing can already be enabled. Also, a bind cannot be currently in progress on the connection, nor can there be any outstanding LDAP requests on the connection. If these conditions are not met, LDAP_UNWILLING_TO_PERFORM is returned. If these conditions are met, the function will send the appropriate extended operation to the server to initiate TLS (SSL), and then negotiate the encryption with the server. If the server rejects the extended operation, LDAP_OTHER will be returned, and the ServerReturnValue should be checked to retrieve the server error code.

It is possible that the server will return a referral in response to this call. For security reasons, the referral will not be automatically chased. A pointer to the referral message is returned in the result parameter.

After ldap_start_tls_s is called, automatic referral chasing and autoreconnect are disabled on the connection. They will be restored to their previous settings upon successful completion of the ldap_stop_tls_s operation.

This function has a default timeout of about thirty seconds. That timeout is used in waiting for responses from the server for the Start TLS extended operation and during the TLS (SSL) negotiation.

For more information about start-stop TLS encryption, see Using Start-Stop TLS Encryption.

Note

The winldap.h header defines ldap_start_tls_s as an alias which automatically selects the ANSI or Unicode version of this function based on the definition of the UNICODE preprocessor constant. Mixing usage of the encoding-neutral alias with code that not encoding-neutral can lead to mismatches that result in compilation or runtime errors. For more information, see Conventions for Function Prototypes.

Requirements

   
Minimum supported client Windows Vista
Minimum supported server Windows Server 2008
Target Platform Windows
Header winldap.h
Library Wldap32.lib
DLL Wldap32.dll

See also

Using Start-Stop TLS Encryption

ldap_stop_tls_s