11 C API Reference

This chapter introduces the Oracle Internet Directory C API and provides examples of how to use it.

The chapter contains these topics:

About the Oracle Internet Directory C API
Functions in the C API
Sample C API Usage
Required Header Files and Libraries for the C API
Dependencies and Limitations of the C API

11.1 About the Oracle Internet Directory C API

The Oracle Internet Directory SDK C API is based on LDAP Version 3 C API and Oracle extensions to support SSL.

You can use the Oracle Internet Directory API 10g Release 2 (10.1.2) in the following modes:

SSL—All communication secured by using SSL
Non-SSL—Client/server communication not secure

The API uses TCP/IP to connect to a directory server. When it does this, it uses, by default, an unencrypted channel. To use the SSL mode, you must use the Oracle SSL call interface. You determine which mode you are using by the presence or absence of the SSL calls in the API usage. You can easily switch between SSL and non-SSL modes.

See Also:

"Sample C API Usage" for more details on how to use the two modes

This section contains these topics:

Oracle Internet Directory SDK C API SSL Extensions
The Functions at a Glance

11.1.1 Oracle Internet Directory SDK C API SSL Extensions

Oracle SSL extensions to the LDAP API are based on standard SSL protocol. The SSL extensions provide encryption and decryption of data over the wire and authentication.

There are three modes of authentication:

None—Neither client nor server is authenticated, and only SSL encryption is used
One-way—Only the server is authenticated by the client
Two-way—Both the server and the client are authenticated by each other

The type of authentication is indicated by a parameter in the SSL interface call.

11.1.1.1 SSL Interface Calls

There is only one call required to enable SSL:

int ldap_init_SSL(Sockbuf *sb, text *sslwallet, text *sslwalletpasswd, int sslauthmode)

The ldap_init_SSL call performs the necessary handshake between client and server using the standard SSL protocol. If the call is successful, then all subsequent communication happens over a secure connection.

Table 11-1 Arguments for SSL Interface Calls

Argument	Description
sb	Socket buffer handle returned by the `ldap_open` call as part of LDAP handle.
sslwallet	Location of the user wallet.
sslwalletpasswd	Password required to use the wallet.
sslauthmode	SSL authentication mode user wants to use. Possible values are: `GSLC_SSL_NO_AUTH`—No authentication required `GSLC_SSL_ONEWAY_AUTH`—Only server authentication required. `GSLC_SSL_TWOWAY_AUTH`—Both server and client authentication required. A return value of `0` indicates success. A nonzero return value indicates an error. The error code can be decoded by using the function `ldap_err2string`.

See Also:

"Sample C API Usage"

11.1.1.2 Wallet Support

depending on which authentication mode is being used, both the server and the client may require wallets to use the SSL feature. 10g Release 2 (10.1.2) of the API supports only the Oracle Wallet. You can create wallets by using Oracle Wallet Manager.

11.2 Functions in the C API

This section examines each of the functions and procedures in the C API. It explains their purpose and syntax. It also provides tips for using them.

The section contains the following topics:

The Functions at a Glance
Initializing an LDAP Session
LDAP Session Handle Options
Authenticating to the Directory
SASL Authentication Using Oracle Extensions
SASL Authentication
Working With Controls
Closing the Session
Performing LDAP Operations
Abandoning an Operation
Obtaining Results and Peeking Inside LDAP Messages
Handling Errors and Parsing Results
Stepping Through a List of Results
Parsing Search Results

11.2.1 The Functions at a Glance

Table 11-2 lists all of the functions and procedures in the C API and briefly explains their purpose.

Table 11-2 Functions and Procedures in the C API

Function or Procedure	Description
ber_free	Free the memory allocated for a BerElement structure
ldap_abandon_ext ldap_abandon	Cancel an asynchronous operation
ldap_add_ext ldap_add_ext_s ldap_add ldap_add_s	Add a new entry to the directory
ldap_compare_ext ldap_compare_ext_s ldap_compare ldap_compare_s	Compare entries in the directory
ldap_count_entries	Count the number of entries in a chain of search results
ldap_count_values	Count the string values of an attribute
ldap_count_values_len	Count the binary values of an attribute
ora_ldap_create_clientctx	Create a client context and returns a handle to it.
ora_ldap_create_cred_hdl	Create a credential handle.
ldap_delete_ext ldap_delete_ext_s ldap_delete ldap_delete_s	Delete an entry from the directory
ora_ldap_destroy_clientctx	Destroy the client context.
ora_ldap_free_cred_hdl	Destroy the credential handle.
ldap_dn2ufn	Converts the name into a more user friendly format
ldap_err2string	Get the error message for a specific error code
ldap_explode_dn	Split up a distinguished name into its components
ldap_explode_rdn
ldap_first_attribute	Get the name of the first attribute in an entry
ldap_first_entry	Get the first entry in a chain of search results
ora_ldap_get_cred_props	Retrieve properties associated with credential handle.
ldap_get_dn	Get the distinguished name for an entry
ldap_get_option	Access the current value of various session-wide parameters
ldap_get_values	Get the string values of an attribute
ldap_get_values_len	Get the binary values of an attribute
ldap_init ldap_open	Open a connection to an LDAP server
ora_ldap_init_SASL	Perform SASL authentication
ldap_memfree	Free memory allocated by an LDAP API function call
ldap_modify_ext ldap_modify_ext_s ldap_modify ldap_modify_s	Modify an entry in the directory
ldap_msgfree	Free the memory allocated for search results or other LDAP operation results
ldap_first_attribute ldap_next_attribute	Get the name of the next attribute in an entry
ldap_next_entry	Get the next entry in a chain of search results
ldap_perror (Deprecated)	Prints the message supplied in message.
ldap_rename ldap_rename_s	Modify the RDN of an entry in the directory
ldap_result2error (Deprecated)	Return the error code from result message.
ldap_result ldap_msgfree ldap_msgtype ldap_msgid	Check the results of an asynchronous operation
ldap_sasl_bind ldap_sasl_bind_s	General authentication to an LDAP server
ldap_search_ext ldap_search_ext_s ldap_search ldap_search_s	Search the directory
ldap_search_st	Search the directory with a timeout value
ldap_get_option ldap_set_option	Set the value of these parameters
ora_ldap_set_clientctx	Add properties to the client context handle.
ora_ldap_set_cred_props	Add properties to credential handle.
ldap_simple_bind ldap_simple_bind_s ldap_sasl_bind ldap_sasl_bind_s	Simple authentication to an LDAP server
ldap_unbind_ext ldap_unbind ldap_unbind_s	End an LDAP session
ldap_value_free	Free the memory allocated for the string values of an attribute
ldap_value_free ldap_value_free_len	Free the memory allocated for the binary values of an attribute

This section lists all the calls available in the LDAP C API found in RFC 1823.

See Also:

The following URL for a more detailed explanation of these calls:

http://www.ietf.org

11.2.2 Initializing an LDAP Session

The calls in this section initialize a session with an LDAP server.

11.2.2.1 ldap_init and ldap_open

ldap_init() initializes a session with an LDAP server, but does not open a connection. The server is not actually contacted until an operation is performed that requires it, allowing various options to be set after initialization. ldap_open() initializes a session and opens a connection. The two fulfill the same purpose and have the same syntax, but the first is preferred.

Syntax

LDAP *ldap_init
(
    const char     *hostname,
    int            portno
)
;

Parameters

Table 11-3 Parameters for Initializing an LDAP Session

Parameter Description

Parameter	Description
hostname	Contains a space-separated list of host names or dotted strings representing the IP address of hosts running an LDAP server to connect to. Each host name in the list may include a port number. The two must be separated by a colon. The hosts are tried in the order listed until a successful connection occurs. Note: A suitable representation for including a literal IPv6[10] address in the host name parameter is desired, but has not yet been determined or implemented in practice.
portno	Contains the TCP port number to connect to. The default LDAP port of `389` can be obtained by supplying the constant `LDAP_PORT`. If `hostname` includes a port number, `portno` is ignored.

hostname

Contains a space-separated list of host names or dotted strings representing the IP address of hosts running an LDAP server to connect to. Each host name in the list may include a port number. The two must be separated by a colon. The hosts are tried in the order listed until a successful connection occurs.

Note: A suitable representation for including a literal IPv6[10] address in the host name parameter is desired, but has not yet been determined or implemented in practice.

portno

Contains the TCP port number to connect to. The default LDAP port of 389 can be obtained by supplying the constant LDAP_PORT. If hostname includes a port number, portno is ignored.

Usage Notes

ldap_init() and ldap_open() both return a session handle. This is a pointer to an opaque structure that must be passed to subsequent calls pertaining to the session. These routines return NULL if the session cannot be initialized. If the session cannot be initialized, check the error reporting mechanism for the operating system to see why the call failed.

Note that if you connect to an LDAPv2 server, one of the LDAP bind calls described later SHOULD be completed before other operations can be performed on the session. LDAPv3 does not require that a bind operation be completed before other operations are performed.

The calling program can set various attributes of the session by calling the routines described in the next section.

11.2.3 LDAP Session Handle Options

The LDAP session handle returned by ldap_init() is a pointer to an opaque data type representing an LDAP session. In RFC 1823 this data type was a structure exposed to the caller, and various fields in the structure could be set to control aspects of the session, such as size and time limits on searches.

In the interest of insulating callers from inevitable changes to this structure, these aspects of the session are now accessed through a pair of accessor functions, described in this section.

11.2.3.1 ldap_get_option and ldap_set_option

ldap_get_option() is used to access the current value of various session-wide parameters. ldap_set_option() is used to set the value of these parameters. Note that some options are read only and cannot be set; it is an error to call ldap_set_option() and attempt to set a read only option.

Note that if automatic referral following is enabled (the default), any connections created during the course of following referrals will inherit the options associated with the session that sent the original request that caused the referrals to be returned.

Syntax

int ldap_get_option
(

LDAP            *ld,
int             option,
void            *outvalue

)
;

int ldap_set_option
(

LDAP            *ld,
int             option,
const void      *invalue

)
;

#define LDAP_OPT_ON     ((void *)1)
#define LDAP_OPT_OFF    ((void *)0)

Parameters

Table 11-4 lists and describes the parameters for LDAP session handle options.

Table 11-4 Parameters for LDAP Session Handle Options

Parameters	Description
ld	The session handle. If this is `NULL`, a set of global defaults is accessed. New LDAP session handles created with `ldap_init()` or `ldap_open()` inherit their characteristics from these global defaults.
option	The name of the option being accessed or set. This parameter should be one of the constants listed and described in Table 11-5. The hexadecimal value of the constant is listed in parentheses after the constant.
outvalue	The address of a place to put the value of the option. The actual type of this parameter depends on the setting of the option parameter. For outvalues of type `char ` and `LDAPControl `, a copy of the data that is associated with the LDAP session `ld` is returned. Callers should dispose of the memory by calling `ldap_memfree()` or `ldap_controls_free()`, depending on the type of data returned.
invalue	A pointer to the value the option is to be given. The actual type of this parameter depends on the setting of the option parameter. The data associated with invalue is copied by the API implementation to allow callers of the API to dispose of or otherwise change their copy of the data after a successful call to `ldap_set_option()`. If a value passed for invalue is invalid or cannot be accepted by the implementation, `ldap_set_option()` should return `-1` to indicate an error.

Constants

Table 11-5 lists and describes the constants for LDAP session handle options.

Table 11-5 Constants

Constant	Type for invalue parameter	Type for outvalue parameter	Description
LDAP_OPT_API_INFO(0x00)	Not applicable. Option is read only.	LDAPAPIInfo*	Used to retrieve some basic information about the LDAP API implementation at execution time. Applications need to be able to determine information about the particular API implementation they are using both at compile time and during execution. This option is read only and cannot be set.
ORA_LDAP_OPT_RFRL_CACHE	void* (LDAP_OPT_ON void* (LDAP_OPT_OFF)	int *	This option determines whether referral cache is enabled or not. If this option is set to `LDAP_OPT_ON`, the cache is enabled; otherwise, the cache is disabled.
ORA_LDAP_OPT_RFRL_CACHE_SZ	int *	int *	This option sets the size of referral cache. The size is maximum size in terms of number of bytes the cache can grow to. It is set to 1MB by default.
LDAP_OPT_DEREF(0x02)	int *	int *	Determines how aliases are handled during search. It should have one of the following values: `LDAP_DEREF_NEVER (0x00)`, `LDAP_DEREF SEARCHING (0x01)`, `LDAP_DEREF_FINDING (0x02)`, or `LDAP_DEREF_ALWAYS (0x03)`. The `LDAP_DEREF_SEARCHING` value means aliases are dereferenced during the search but not when locating the base object of the search. The `LDAP_DEREF_FINDING` value means aliases are dereferenced when locating the base object but not during the search. The default value for this option is `LDAP_DEREF_NEVER`.
LDAP_OPT_SIZELIMIT(0x03)	int *	int *	A limit on the number of entries to return from a search. A value of `LDAP_NO_LIMIT (0)` means no limit. The default value for this option is `LDAP_NO_LIMIT`.
LDAP_OPT_TIMELIMIT(0x04)	int *	int *	A limit on the number of seconds to spend on a search. A value of `LDAP_NO_LIMIT (0)` means no limit. This value is passed to the server in the search request only; it does not affect how long the C LDAP API implementation itself will wait locally for search results. The timeout parameter passed to `ldap_search_ext_s()` or `ldap_result()`—both of which are described later in this document—can be used to specify both a local and server side time limit. The default value for this option is `LDAP_NO_LIMIT`.
LDAP_OPT_REFERRALS(0x08)	void (LDAP_OPT_ON) void (LDAP_OPT_OFF)	int *	Determines whether the LDAP library automatically follows referrals returned by LDAP servers or not. It may be set to one of the constants `LDAP_OPT_ON` or `LDAP_OPT_OFF`. Any non-null pointer value passed to `ldap_set_option()` enables this option. When the current setting is read using `ldap_get_option()`, a zero value means off and any nonzero value means on. By default, this option is turned on.
LDAP_OPT_RESTART(0X09)	void * (LDAP_OPT_ON) void * (LDAP_OPT_OFF)	int *	Determines whether LDAP input and output operations are automatically restarted if they stop prematurely. It may be set to either `LDAP_OPT_ON` or `LDAP_OPT_OFF`. Any non-null pointer value passed to `ldap_set_option()` enables this option. When the current setting is read using `ldap_get_option()`, a zero value means off and any nonzero value means on. This option is useful if an input or output operation can be interrupted prematurely—by a timer going off, for example. By default, this option is turned off.
LDAP_OPT_PROTOCOL_VERSION(0x11)	int *	int *	This option indicates the version of the LDAP protocol used when communicating with the primary LDAP server. The option should be either `LDAP_VERSION2 (2)` or `LDAP_VERSION3 (3)`. If no version is set, the default is `LDAP_VERSION2 (2)`.
LDAP_OPT_SERVER_CONTROLS(0x12)	LDAPControl**	LDAPControl***	A default list of LDAP server controls to be sent with each request. See Also: "Working With Controls"
LDAP_OPT_CLIENT_CONTROLS(0x13)	LDAPControl**	LDAPControl***	A default list of client controls that affect the LDAP session. See Also: "Working With Controls"
LDAP_OPT_API_FEATURE_INFO(0x15)	Not applicable. Option is read only.	LDAPAPIFeatureInfo *	Used to retrieve version information about LDAP API extended features at execution time. Applications need to be able to determine information about the particular API implementation they are using both at compile time and during execution. This option is read only. It cannot be set.
LDAP_OPT_HOST_NAME(0x30)	char *	char **	The host name (or list of hosts) for the primary LDAP server. See the definition of the `hostname` parameter for `ldap_init()` to determine the syntax.
LDAP_OPT_ERROR_NUMBER(0x31)	int *	int *	The code of the most recent LDAP error during this session.
LDAP_OPT_ERROR_STRING(0x32)	char *	-	The message returned with the most recent LDAP error during this session.
LDAP_OPT_MATCHED_DN(0x33)	char *	char **	The matched DN value returned with the most recent LDAP error during this session.

Usage Notes

Both ldap_get_option() and ldap_set_option() return 0 if successful and -1 if an error occurs. If -1 is returned by either function, a specific error code may be retrieved by calling ldap_get_option() with an option value of LDAP_OPT_ERROR_NUMBER. Note that there is no way to retrieve a more specific error code if a call to ldap_get_option() with an option value of LDAP_OPT_ERROR_NUMBER fails.

When a call to ldap_get_option() succeeds, the API implementation MUST NOT change the state of the LDAP session handle or the state of the underlying implementation in a way that affects the behavior of future LDAP API calls. When a call to ldap_get_option() fails, the only session handle change permitted is setting the LDAP error code (as returned by the LDAP_OPT_ERROR_NUMBER option).

When a call to ldap_set_option() fails, it must not change the state of the LDAP session handle or the state of the underlying implementation in a way that affects the behavior of future LDAP API calls.

Standards track documents that extend this specification and specify new options should use values for option macros that are between 0x1000 and 0x3FFF inclusive. Private and experimental extensions should use values for the option macros that are between 0x4000 and 0x7FFF inclusive. All values less than 0x1000 and greater than 0x7FFF that are not defined in this document are reserved and should not be used. The following macro must be defined by C LDAP API implementations to aid extension implementers:

#define LDAP_OPT_PRIVATE_EXTENSION_BASE 0x4000  /* to 0x7FFF inclusive */

11.2.4 Authenticating to the Directory

The functions in this section are used to authenticate an LDAP client to an LDAP directory server.

11.2.4.1 ldap_sasl_bind, ldap_sasl_bind_s, ldap_simple_bind, and ldap_simple_bind_s

The ldap_sasl_bind() and ldap_sasl_bind_s() functions can be used to do general and extensible authentication over LDAP through the use of the Simple Authentication Security Layer. The routines both take the DN to bind as, the method to use, as a dotted-string representation of an object identifier (OID) identifying the method, and a struct berval holding the credentials. The special constant value LDAP_SASL_SIMPLE (NULL) can be passed to request simple authentication, or the simplified routines ldap_simple_bind() or ldap_simple_bind_s() can be used.

Syntax

int ldap_sasl_bind
(

LDAP                    *ld,
const char              *dn,
const char              *mechanism,
const struct berval     *cred,
LDAPControl             **serverctrls,
LDAPControl             **clientctrls,
int                     *msgidp
);

int ldap_sasl_bind_s(

LDAP                    *ld,
const char              *dn,
const char              *mechanism,
const struct berval     *cred,
LDAPControl             **serverctrls,
LDAPControl             **clientctrls,
struct berval           **servercredp

);

int ldap_simple_bind(

LDAP                    *ld,
const char              *dn,
const char              *passwd

);

int ldap_simple_bind_s(

LDAP                    *ld,
const char              *dn,
const char              *passwd

);

The use of the following routines is deprecated and more complete descriptions can be found in RFC 1823:

int ldap_bind( LDAP *ld, const char *dn, const char *cred, int method );
int ldap_bind_s( LDAP *ld, const char *dn, const char *cred, int method );
int ldap_kerberos_bind( LDAP *ld, const char *dn );
int ldap_kerberos_bind_s( LDAP *ld, const char *dn );

Parameters

Table 11-6 lists and describes the parameters for authenticating to the directory.

Table 11-6 Parameters for Authenticating to the Directory

Parameter	Description
ld	The session handle
dn	The name of the entry to bind as
mechanism	Either `LDAP_SASL_SIMPLE (NULL)` to get simple authentication, or a text string identifying the SASL method
cred	The credentials with which to authenticate. Arbitrary credentials can be passed using this parameter. The format and content of the credentials depends on the setting of the mechanism parameter.
passwd	For `ldap_simple_bind()`, the password to compare to the entry's userPassword attribute
serverctrls	List of LDAP server controls
clientctrls	List of client controls
msgidp	This result parameter will be set to the message id of the request if the `ldap_sasl_bind()` call succeeds
servercredp	This result parameter will be filled in with the credentials passed back by the server for mutual authentication, if given. An allocated `berval` structure is returned that should be disposed of by calling `ber_bvfree()`. `NULL` should be passed to ignore this field.

Usage Notes

Additional parameters for the deprecated routines are not described. Interested readers are referred to RFC 1823.

The ldap_sasl_bind() function initiates an asynchronous bind operation and returns the constant LDAP_SUCCESS if the request was successfully sent, or another LDAP error code if not. If successful, ldap_sasl_bind() places the message id of the request in *msgidp. A subsequent call to ldap_result() can be used to obtain the result of the bind.

The ldap_simple_bind() function initiates a simple asynchronous bind operation and returns the message id of the operation initiated. A subsequent call to ldap_result(), described in, can be used to obtain the result of the bind. In case of error, ldap_simple_bind() will return -1, setting the session error parameters in the LDAP structure appropriately.

The synchronous ldap_sasl_bind_s() and ldap_simple_bind_s() functions both return the result of the operation, either the constant LDAP_SUCCESS if the operation was successful, or another LDAP error code if it was not.

Note that if an LDAPv2 server is contacted, no other operations over the connection can be attempted before a bind call has successfully completed.

Subsequent bind calls can be used to re-authenticate over the same connection, and multistep SASL sequences can be accomplished through a sequence of calls to ldap_sasl_bind() or ldap_sasl_bind_s().

See Also:

"Handling Errors and Parsing Results" for more information about possible errors and how to interpret them

11.2.5 SASL Authentication Using Oracle Extensions

The function ora_ldap_init_SASL() can be used for SASL based authentication. It accepts these arguments:

DN of the entity to be authenticated.
SASL credential handle for the entity. (This handle can be managed using ora_ldap_create_cred_hdl(), ora_ldap_set_cred_props() and ora_ldap_free_cred_hdl() functions).
SASL mechanism to be used.

This function encapsulates the SASL handshake between the client and the directory server for various standard SASL mechanisms thereby reducing the coding effort involved in establishing a SASL-based connection to the directory server.

Supported SASL mechanisms:

DIGEST-MD5

The SASL API supports the authentication-only mode of DIGEST-MD5. The other two authentication modes addressing data privacy and data integrity are yet to be supported.

While authenticating against Oracle Internet Directory, the DN of the user has to be normalized before it is sent across to the server. This can be done either outside the SASL API using the ora_ldap_normalize_dn() function before the DN is passed on to the SASL API or with the SASL API by setting the ORA_LDAP_CRED_SASL_NORM_AUTHDN option in SASL credentials handle using ora_ldap_set_cred_handle().
EXTERNAL:

The SASL API and SASL implementation in Oracle Internet Directory use SSL authentication as one of the external authentication mechanisms.

Using this mechanism requires that the SSL connection (mutual authentication mode) be established to the directory server by using the ora_ldap_init_SSL() function. The ora_ldap_init_SASL() function can then be invoked with the mechanism argument as EXTERNAL. The directory server would then authenticate the user based on the user credentials in SSL connection.

11.2.5.1 ora_ldap_create_cred_hdl, ora_ldap_set_cred_props, ora_ldap_get_cred_props, and ora_ldap_free_cred_hdl

Use these functions to create and manage SASL credential handles. The ora_ldap_create_cred_hdl function should be used to create a SASL credential handle of certain type based on the type of mechanism used for SASL authentication. The ora_ldap_set_cred_props() function can be used to add relevant credentials to the handle needed for SASL authentication. The ora_ldap_get_cred_props() function can be used for retrieving the properties stored in the credential handle, and the ora_ldap_free_cred_hdl() function should be used to destroy the handle after its use.

Syntax

OraLdapHandle ora_ldap_create_cred_hdl
(
        OraLdapClientCtx * clientCtx,
        int                 credType
); 

OraLdapHandle ora_ldap_set_cred_props
(
        OraLdapClientCtx *   clientCtx,
        OraLdapHandle        cred,
        int                  String[],
        void             *   inProperty
); 
OraLdapHandle ora_ldap_get_cred_props
(
        OraLdapClientCtx *   clientCtx,
        OraLdapHandle   cred,
        int                     String[],
        void                   *   outProperty
); 

OraLdapHandle ora_ldap_free_cred_hdl 
(
        OraLdapClientCtx *   clientCtx,
        OraLdapHandle   cred
);

Parameters

Table 11-7 Parameters for Managing SASL Credentials

Parameter	Description
clientCtx	C API Client context. This can be managed using `ora_ldap_init_clientctx()` and `ora_ldap_free_clientctx()` functions.
credType	Type of credential handle specific to SASL mechanism.
cred	Credential handle containing SASL credentials needed for a specific SASL mechanism for SASL authentication.
String[]	Type of credential, which needs to be added to credential handle.
inProperty	One of the SASL Credentials to be stored in credential handle.
outProperty	One of the SASL credentials stored in credential handle.

11.2.6 SASL Authentication

ora_ldap_init_SASL, the lone function in this section, performs SASL authentication.

11.2.6.1 ora_ldap_init_SASL

ora_ldap_init_SASL performs authentication based on the mechanism specified as one of its input arguments.

Syntax

int ora_ldap_init_SASL
(
		OraLdapClientCtx * clientCtx,
		LDAP			*ld,
		char			* dn,
		char			* mechanism,
		OraLdapHandle		 cred,
		LDAPControl			**serverctrls,
		LDAPControl			**clientctrls
);

Parameters

Table 11-8 Parameters for Managing SASL Credentials

Parameter	Description
clientCtx	C API Client context. This can be managed using `ora_ldap_init_clientctx()` and `ora_ldap_free_clientctx()` functions.
ld	Ldap session handle.
dn	User DN that requires authentication.
mechanism	SASL mechanism.
cred	Credentials needed for SASL authentication.
serverctrls	List of LDAP server controls
clientctrls	List of client controls

11.2.7 Working With Controls

LDAPv3 operations can be extended through the use of controls. Controls can be sent to a server or returned to the client with any LDAP message. These controls are referred to as server controls.

The LDAP API also supports a client-side extension mechanism through the use of client controls. These controls affect the behavior of the LDAP API only and are never sent to a server. A common data structure is used to represent both types of controls:

typedef struct ldapcontrol 
{

char            *ldctl_oid;
struct berval   ldctl_value;
char            ldctl_iscritical;

} LDAPControl;

The fields in the ldapcontrol structure are described in Table 11-9.

Table 11-9 Fields in ldapcontrol Structure

Field	Description
ldctl_oid	The control type, represented as a string.
ldctl_value	The data associated with the control (if any). To specify a zero-length value, set `ldctl_value.bv_len` to zero and `ldctl_value.bv_val` to a zero-length string. To indicate that no data is associated with the control, set `ldctl_value.bv_val` to `NULL`.
ldctl_iscritical	Indicates whether the control is critical of not. If this field is nonzero, the operation will only be carried out if the control is recognized by the server or the client. Note that the LDAP unbind and abandon operations have no server response. Clients should not mark server controls critical when used with these two operations.

Some LDAP API calls allocate an ldapcontrol structure or a NULL-terminated array of ldapcontrol structures. The following routines can be used to dispose of a single control or an array of controls:

void ldap_control_free( LDAPControl *ctrl );
void ldap_controls_free( LDAPControl **ctrls );

If the ctrl or ctrls parameter is NULL, these calls do nothing.

A set of controls that affect the entire session can be set using the ldap_set_option() function described in "ldap_get_option and ldap_set_option". A list of controls can also be passed directly to some LDAP API calls such as ldap_search_ext(), in which case any controls set for the session through the use of ldap_set_option() are ignored. Control lists are represented as a NULL-terminated array of pointers to ldapcontrol structures.

Server controls are defined by LDAPv3 protocol extension documents; for example, a control has been proposed to support server-side sorting of search results.

One client control is defined in this document (described in the following section). Other client controls may be defined in future revisions of this document or in documents that extend this API.

Client-Controlled Referral Processing As described previously in "LDAP Session Handle Options", applications can enable and disable automatic chasing of referrals on a session-wide basic by using the ldap_set_option() function with the LDAP_OPT_REFERRALS option. It is also useful to govern automatic referral chasing on per-request basis. A client control with an object identifier (OID) of 1.2.840.113556.1.4.616 exists to provide this functionality.

/* OID for referrals client control */
#define LDAP_CONTROL_REFERRALS              "1.2.840.113556.1.4.616"

/* Flags for referrals client control value */
#define LDAP_CHASE_SUBORDINATE_REFERRALS    0x00000020U
#define LDAP_CHASE_EXTERNAL_REFERRALS       0x00000040U

To create a referrals client control, the ldctl_oid field of an LDAPControl structure must be set to LDAP_CONTROL_REFERRALS ("1.2.840.113556.1.4.616") and the ldctl_value field must be set to a four-octet value that contains a set of flags. The ldctl_value.bv_len field must always be set to 4. The ldctl_value.bv_val field must point to a four-octet integer flags value. This flags value can be set to zero to disable automatic chasing of referrals and LDAPv3 references altogether. Alternatively, the flags value can be set to the value LDAP_CHASE_SUBORDINATE_REFERRALS (0x00000020U) to indicate that only LDAPv3 search continuation references are to be automatically chased by the API implementation, to the value LDAP_CHASE_EXTERNAL_REFERRALS (0x00000040U) to indicate that only LDAPv3 referrals are to be automatically chased, or the logical OR of the two flag values (0x00000060U) to indicate that both referrals and references are to be automatically chased.

See Also:

"Directory Schema Administration" in Oracle Internet Directory Administrator's Guide for more information about object identifiers

11.2.8 Closing the Session

Use the functions in this section to unbind from the directory, to close open connections, and to dispose of the session handle.

11.2.8.1 ldap_unbind, ldap_unbind_ext, and ldap_unbind_s

ldap_unbind_ext(), ldap_unbind(), and ldap_unbind_s() all work synchronously in the sense that they send an unbind request to the server, close all open connections associated with the LDAP session handle, and dispose of all resources associated with the session handle before returning. Note, however, that there is no server response to an LDAP unbind operation. All three of the unbind functions return LDAP_SUCCESS (or another LDAP error code if the request cannot be sent to the LDAP server). After a call to one of the unbind functions, the session handle ld is invalid and it is illegal to make any further LDAP API calls using ld.

The ldap_unbind() and ldap_unbind_s() functions behave identically. The ldap_unbind_ext() function allows server and client controls to be included explicitly, but note that since there is no server response to an unbind request there is no way to receive a response to a server control sent with an unbind request.

Syntax

int ldap_unbind_ext( LDAP *ld, LDAPControl **serverctrls,
LDAPControl **clientctrls );
int ldap_unbind( LDAP *ld );
int ldap_unbind_s( LDAP *ld );

Parameters

Table 11-10 Parameters for Closing the Session

Parameter

Description

ld

The session handle

serverctrls

List of LDAP server controls

clientctrls

clientctrls

List of client controls

11.2.9 Performing LDAP Operations

Use the functions in this section to search the LDAP directory and to return a requested set of attributes for each entry matched.

11.2.9.1 ldap_search_ext, ldap_search_ext_s, ldap_search, and ldap_search_s

The ldap_search_ext() function initiates an asynchronous search operation and returns the constant LDAP_SUCCESS if the request was successfully sent, or another LDAP error code if not. If successful, ldap_search_ext() places the message id of the request in *msgidp. A subsequent call to ldap_result() can be used to obtain the results from the search. These results can be parsed using the result parsing routines described in detail later.

Similar to ldap_search_ext(), the ldap_search() function initiates an asynchronous search operation and returns the message id of the operation initiated. As for ldap_search_ext(), a subsequent call to ldap_result() can be used to obtain the result of the bind. In case of error, ldap_search() will return -1, setting the session error parameters in the LDAP structure appropriately.

The synchronous ldap_search_ext_s(), ldap_search_s(), and ldap_search_st() functions all return the result of the operation, either the constant LDAP_SUCCESS if the operation was successful, or another LDAP error code if it was not. Entries returned from the search, if any, are contained in the res parameter. This parameter is opaque to the caller. Entries, attributes, values, and so on, can be extracted by calling the parsing routines described in this section. The results contained in res should be freed when no longer in use by calling ldap_msgfree(), which is described later.

The ldap_search_ext() and ldap_search_ext_s() functions support LDAPv3 server controls, client controls, and allow varying size and time limits to be easily specified for each search operation. The ldap_search_st() function is identical to ldap_search_s() except that it takes an additional parameter specifying a local timeout for the search. The local search timeout is used to limit the amount of time the API implementation will wait for a search to complete. After the local search timeout expires, the API implementation will send an abandon operation to stop the search operation.

See Also:

"Handling Errors and Parsing Results" for more information about possible errors and how to interpret them

Syntax

int ldap_search_ext
(

LDAP            *ld,
const char      *base,
int             scope,
const char      *filter,
char            **attrs,
int             attrsonly,
LDAPControl     **serverctrls,
LDAPControl     **clientctrls,
struct timeval  *timeout,
int             sizelimit,
int             *msgidp

);

int ldap_search_ext_s
(

LDAP            *ld,
const char      *base,
int             scope,
const char      *filter,
char            **attrs,
int             attrsonly,
LDAPControl     **serverctrls,
LDAPControl     **clientctrls,
struct timeval  *timeout,
int             sizelimit,
LDAPMessage     **res

);

int ldap_search
(

LDAP            *ld,
const char      *base,
int             scope,
const char      *filter,
char            **attrs,
int             attrsonly

);

int ldap_search_s
(

LDAP            *ld,
const char      *base,
int             scope,
const char      *filter,
char            **attrs,
int             attrsonly,
LDAPMessage     **res

);

int ldap_search_st
);

LDAP            *ld,
const char      *base,
int             scope,
const char      *filter,
char            **attrs,
int             attrsonly,
struct timeval  *timeout,
LDAPMessage     **res

);

Parameters

Table 11-11 lists and describes the parameters for search operations.

Table 11-11 Parameters for Search Operations

Parameter	Description
ld	The session handle.
base	The DN of the entry at which to start the search.
scope	One of `LDAP_SCOPE_BASE (0x00)`, `LDAP_SCOPE_ONELEVEL (0x01)`, or `LDAP_SCOPE_SUBTREE (0x02)`, indicating the scope of the search.
filter	A character string representing the search filter. The value `NULL` can be passed to indicate that the filter `"(objectclass=*)"` which matches all entries is to be used. Note that if the caller of the API is using LDAPv2, only a subset of the filter functionality can be successfully used.
attrs	A `NULL`-terminated array of strings indicating which attributes to return for each matching entry. Passing `NULL` for this parameter causes all available user attributes to be retrieved. The special constant string `LDAP_NO_ATTRS ("1.1")` may be used as the only string in the array to indicate that no attribute types are to be returned by the server. The special constant string `LDAP_ALL_USER_ATTRS ("*")` can be used in the `attrs` array along with the names of some operational attributes to indicate that all user attributes plus the listed operational attributes are to be returned.
attrsonly	A boolean value that must be zero if both attribute types and values are to be returned, and nonzero if only types are wanted.
timeout	For the `ldap_search_st()` function, this specifies the local search timeout value (if it is `NULL`, the timeout is infinite). If a zero timeout (where `tv_sec` and `tv_usec are` both zero) is passed, API implementations should return `LDAP_PARAM_ERROR`. For the `ldap_search_ext()` and `ldap_search_ext_s()` functions, the timeout parameter specifies both the local search timeout value and the operation time limit that is sent to the server within the search request. Passing a `NULL` value for timeout causes the global default timeout stored in the LDAP session handle (set by using `ldap_set_option()` with the `LDAP_OPT_TIMELIMIT` parameter) to be sent to the server with the request but an infinite local search timeout to be used. If a zero timeout (where `tv_sec` and `tv_usec` are both zero) is passed in, API implementations should return `LDAP_PARAM_ERROR`. If a zero value for `tv_sec` is used but `tv_usec` is nonzero, an operation time limit of `1` should be passed to the LDAP server as the operation time limit. For other values of `tv_sec`, the `tv_sec` value itself should be passed to the LDAP server.
sizelimit	For the `ldap_search_ext()` and `ldap_search_ext_s()` calls, this is a limit on the number of entries to return from the search. A value of `LDAP_NO_LIMIT (0)` means no limit.
res	For the synchronous calls, this is a result parameter which will contain the results of the search upon completion of the call. If no results are returned, `*res` is set to `NULL`.
serverctrls	List of LDAP server controls.
clientctrls	List of client controls.
msgidp	This result parameter will be set to the message id of the request if the `ldap_search_ext()` call succeeds.There are three options in the session handle `ld` which potentially affect how the search is performed. They are: `LDAP_OPT_SIZELIMIT`—A limit on the number of entries to return from the search. A value of `LDAP_NO_LIMIT` `(0)` means no limit. Note that the value from the session handle is ignored when using the `ldap_search_ext()` or `ldap_search_ext_s()` functions. `LDAP_OPT_TIMELIMIT`—A limit on the number of seconds to spend on the search. A value of `LDAP_NO_LIMIT` `(0)` means no limit. Note that the value from the session handle is ignored when using the `ldap_search_ext()` or `ldap_search_ext_s()` functions. `LDAP_OPT_DEREF`—One of `LDAP_DEREF_NEVER (0x00)`, `LDAP_DEREF_SEARCHING (0x01)`, `LDAP_DEREF_FINDING (0x02)`, or `LDAP_DEREF_ALWAYS` `(0x03)`, specifying how aliases are handled during the search. `The LDAP_DEREF_SEARCHING` value means aliases are dereferenced during the search but not when locating the base object of the search. The `LDAP_DEREF_FINDING` value means aliases are dereferenced when locating the base object but not during the search.

11.2.9.2 Reading an Entry

LDAP does not support a read operation directly. Instead, this operation is emulated by a search with base set to the DN of the entry to read, scope set to LDAP_SCOPE_BASE, and filter set to "(objectclass=*)" or NULL. The attrs parameter contains the list of attributes to return.

11.2.9.3 Listing the Children of an Entry

LDAP does not support a list operation directly. Instead, this operation is emulated by a search with base set to the DN of the entry to list, scope set to LDAP_SCOPE_ONELEVEL, and filter set to "(objectclass=*)" or NULL. The parameter attrs contains the list of attributes to return for each child entry.

11.2.9.4 ldap_compare_ext, ldap_compare_ext_s, ldap_compare, and ldap_compare_s

Use these routines to compare an attribute value assertion against an LDAP entry.

The ldap_compare_ext() function initiates an asynchronous compare operation and returns the constant LDAP_SUCCESS if the request was successfully sent, or another LDAP error code if not. If successful, ldap_compare_ext() places the message id of the request in *msgidp. A subsequent call to ldap_result() can be used to obtain the result of the compare.

Similar to ldap_compare_ext(), the ldap_compare() function initiates an asynchronous compare operation and returns the message id of the operation initiated. As for ldap_compare_ext(), a subsequent call to ldap_result() can be used to obtain the result of the bind. In case of error, ldap_compare() will return -1, setting the session error parameters in the LDAP structure appropriately.

The synchronous ldap_compare_ext_s() and ldap_compare_s() functions both return the result of the operation, either the constant LDAP_SUCCESS if the operation was successful, or another LDAP error code if it was not.

The ldap_compare_ext() and ldap_compare_ext_s() functions support LDAPv3 server controls and client controls.

See Also:

"Handling Errors and Parsing Results" for more information about possible errors and how to interpret them

Syntax

int ldap_compare_ext
(

LDAP                    *ld,
const char              *dn,
const char              *attr,
const struct berval     *bvalue,
LDAPControl             **serverctrls,
LDAPControl             **clientctrls,
int                     *msgidp

);

int ldap_compare_ext_s
(

LDAP                    *ld,
const char              *dn,
const char              *attr,
const struct berval     *bvalue,
LDAPControl             **serverctrls,
LDAPControl             **clientctrls

);

int ldap_compare
(

LDAP                    *ld,
const char              *dn,
const char              *attr,
const char              *value

);
int ldap_compare_s
(

LDAP                    *ld,
const char              *dn,
const char              *attr,
const char              *value

);

Parameters

Table 11-12 lists and describes the parameters for compare operations.

Table 11-12 Parameters for Compare Operations

Parameter	Description
ld	The session handle.
dn	The name of the entry to compare against.
attr	The attribute to compare against.
bvalue	The attribute value to compare against those found in the given entry. This parameter is used in the extended routines and is a pointer to a `struct berval` so it is possible to compare binary values.
value	A string attribute value to compare against, used by the `ldap_compare()` and `ldap_compare_s()` functions. Use `ldap_compare_ext()` or `ldap_compare_ext_s()` if you need to compare binary values.
serverctrls	List of LDAP server controls.
clientctrls	List of client controls.
msgidp	This result parameter will be set to the message id of the request if the `ldap_compare_ext()` call succeeds.

11.2.9.5 ldap_modify_ext, ldap_modify_ext_s, ldap_modify, and ldap_modify_s

Use these routines to modify an existing LDAP entry.

The ldap_modify_ext() function initiates an asynchronous modify operation and returns the constant LDAP_SUCCESS if the request was successfully sent, or another LDAP error code if not. If successful, ldap_modify_ext() places the message id of the request in *msgidp. A subsequent call to ldap_result() can be used to obtain the result of the modify.

Similar to ldap_modify_ext(), the ldap_modify() function initiates an asynchronous modify operation and returns the message id of the operation initiated. As for ldap_modify_ext(), a subsequent call to ldap_result() can be used to obtain the result of the modify. In case of error, ldap_modify() will return -1, setting the session error parameters in the LDAP structure appropriately.

The synchronous ldap_modify_ext_s() and ldap_modify_s() functions both return the result of the operation, either the constant LDAP_SUCCESS if the operation was successful, or another LDAP error code if it was not.

The ldap_modify_ext() and ldap_modify_ext_s() functions support LDAPv3 server controls and client controls.

See Also:

"Handling Errors and Parsing Results" for more information about possible errors and how to interpret them

Syntax

typedef struct ldapmod 
{

int             mod_op;
char            *mod_type;
union mod_vals_u
  {

  char            **modv_strvals;
  struct berval   **modv_bvals;
  } mod_vals;

} LDAPMod;

#define mod_values      mod_vals.modv_strvals
#define mod_bvalues     mod_vals.modv_bvals

int ldap_modify_ext
(

LDAP            *ld,
const char      *dn,
LDAPMod         **mods,
LDAPControl     **serverctrls,
LDAPControl     **clientctrls,
int             *msgidp

);

int ldap_modify_ext_s
(

LDAP            *ld,
const char      *dn,
LDAPMod         **mods,
LDAPControl     **serverctrls,
LDAPControl     **clientctrls

);

int ldap_modify
(

LDAP            *ld,
const char      *dn,
LDAPMod         **mods
);

int ldap_modify_s
(

LDAP            *ld,
const char      *dn,
LDAPMod         **mods

);

Parameters

Table 11-13 lists and describes the parameters for modify operations.

Table 11-13 Parameters for Modify Operations

Parameter	Description
ld	The session handle
dn	The name of the entry to modify
mods	A `NULL`-terminated array of modifications to make to the entry
serverctrls	List of LDAP server controls
clientctrls	List of client controls
msgidp	This result parameter will be set to the message id of the request if the `ldap_modify_ext()` call succeeds

Table 11-14 lists and describes the fields in the LDAPMod structure.

Table 11-14 Fields in LDAPMod Structure

Field	Description
mod_op	The modification operation to perform. It must be one of `LDAP_MOD_ADD (0x00)`, `LDAP_MOD_DELETE (0x01)`, or `LDAP_MOD_REPLACE (0x02)`. This field also indicates the type of values included in the mod_vals union. It is logically ORed with `LDAP_MOD_BVALUES (0x80)` to select the `mod_bvalues` form. Otherwise, the `mod_values` form is used.
mod_type	The type of the attribute to modify.
mod_vals	The values (if any) to add, delete, or replace. Only one of the `mod_values` or `mod_bvalues` variants can be used, selected by `OR`ing the `mod_op` field with the constant `LDAP_MOD_BVALUES`. `mod_values` is a `NULL`-terminated array of zero-terminated strings and mod_bvalues is a `NULL`-terminated array of `berval` structures that can be used to pass binary values such as images.

Usage Notes

For LDAP_MOD_ADD modifications, the given values are added to the entry, creating the attribute if necessary.

For LDAP_MOD_DELETE modifications, the given values are deleted from the entry, removing the attribute if no values remain. If the entire attribute is to be deleted, the mod_vals field can be set to NULL.

For LDAP_MOD_REPLACE modifications, the attribute will have the listed values after the modification, having been created if necessary, or removed if the mod_vals field is NULL. All modifications are performed in the order in which they are listed.

11.2.9.6 ldap_rename and ldap_rename_s

Use these routines to change the name of an entry.

The ldap_rename() function initiates an asynchronous modify DN operation and returns the constant LDAP_SUCCESS if the request was successfully sent, or another LDAP error code if not. If successful, ldap_rename() places the DN message id of the request in *msgidp. A subsequent call to ldap_result() can be used to obtain the result of the rename.

The synchronous ldap_rename_s() returns the result of the operation, either the constant LDAP_SUCCESS if the operation was successful, or another LDAP error code if it was not.

The ldap_rename() and ldap_rename_s() functions both support LDAPv3 server controls and client controls.

See Also:

"Handling Errors and Parsing Results" for more information about possible errors and how to interpret them

Syntax

int ldap_rename
(

LDAP            *ld,
const char      *dn,
const char      *newrdn,
const char      *newparent,
int             deleteoldrdn,
LDAPControl     **serverctrls,
LDAPControl     **clientctrls,
int             *msgidp

);

int ldap_rename_s
(

LDAP            *ld,
const char      *dn,
const char      *newrdn,
const char      *newparent,
int             deleteoldrdn,
LDAPControl     **serverctrls,
LDAPControl     **clientctrls

);

The use of the following routines is deprecated and more complete descriptions can be found in RFC 1823:

int ldap_modrdn
(

LDAP            *ld,
const char      *dn,
const char      *newrdn

);

int ldap_modrdn_s
(

LDAP            *ld,
const char      *dn,
const char      *newrdn

);

int ldap_modrdn2
(

LDAP            *ld,
const char      *dn,
const char      *newrdn,
int             deleteoldrdn

);

int ldap_modrdn2_s
(

LDAP            *ld,
const char      *dn,
const char      *newrdn,
int             deleteoldrdn

);

Parameters

Table 11-15 lists and describes the parameters for rename operations.

Table 11-15 Parameters for Rename Operations

Parameter	Description
ld	The session handle.
dn	The name of the entry whose DN is to be changed.
newrdn	The new RDN to give the entry.
newparent	The new parent, or superior entry. If this parameter is `NULL`, only the RDN of the entry is changed. The root DN should be specified by passing a zero length string, `""`. The newparent parameter should always be `NULL` when using version 2 of the LDAP protocol; otherwise the server's behavior is undefined.
deleteoldrdn	This parameter only has meaning on the rename routines if newrdn is different than the old RDN. It is a boolean value, if nonzero indicating that the old RDN value is to be removed, if zero indicating that the old RDN value is to be retained as non-distinguished values of the entry.
serverctrls	List of LDAP server controls.
clientctrls	List of client controls.
msgidp	This result parameter will be set to the message id of the request if the `ldap_rename()` call succeeds.

11.2.9.7 ldap_add_ext, ldap_add_ext_s, ldap_add, and ldap_add_s

Use these functions to add entries to the LDAP directory.

The ldap_add_ext() function initiates an asynchronous add operation and returns the constant LDAP_SUCCESS if the request was successfully sent, or another LDAP error code if not. If successful, ldap_add_ext() places the message id of the request in *msgidp. A subsequent call to ldap_result() can be used to obtain the result of the add.

Similar to ldap_add_ext(), the ldap_add() function initiates an asynchronous add operation and returns the message id of the operation initiated. As for ldap_add_ext(), a subsequent call to ldap_result() can be used to obtain the result of the add. In case of error, ldap_add() will return -1, setting the session error parameters in the LDAP structure appropriately.

The synchronous ldap_add_ext_s() and ldap_add_s() functions both return the result of the operation, either the constant LDAP_SUCCESS if the operation was successful, or another LDAP error code if it was not.

The ldap_add_ext() and ldap_add_ext_s() functions support LDAPv3 server controls and client controls.

See Also:

"Handling Errors and Parsing Results" for more information about possible errors and how to interpret them

Syntax

int ldap_add_ext
(

LDAP            *ld,
const char      *dn,
LDAPMod         **attrs,
LDAPControl     **serverctrls,
LDAPControl     **clientctrls,
int             *msgidp

);

int ldap_add_ext_s
(

LDAP            *ld,
const char      *dn,
LDAPMod         **attrs,
LDAPControl     **serverctrls,
LDAPControl     **clientctrls

);

int ldap_add
(

LDAP            *ld,
const char      *dn,
LDAPMod         **attrs

);

int ldap_add_s
(

LDAP            *ld,
const char      *dn,
LDAPMod         **attrs

);

Parameters

Table 11-16 lists and describes the parameters for add operations.

Table 11-16 Parameters for Add Operations

Parameter	Description
ld	The session handle.
dn	The name of the entry to add.
attrs	The entry attributes, specified using the `LDAPMod` structure defined for `ldap_modify()`. The mod_type and `mod_vals` fields must be filled in. The `mod_op` field is ignored unless `OR`ed with the constant `LDAP_MOD_BVALUES`, used to select the `mod_bvalues` case of the `mod_vals` union.
serverctrls	List of LDAP server controls.
clientctrls	List of client controls.
msgidp	This result parameter will be set to the message id of the request if the `ldap_add_ext()` call succeeds.

Usage Notes

Note that the parent of the entry being added must already exist or the parent must be empty—that is, equal to the root DN—for an add to succeed.

11.2.9.8 ldap_delete_ext, ldap_delete_ext_s, ldap_delete, and ldap_delete_s

Use these functions to delete a leaf entry from the LDAP directory.

The ldap_delete_ext() function initiates an asynchronous delete operation and returns the constant LDAP_SUCCESS if the request was successfully sent, or another LDAP error code if not. If successful, ldap_delete_ext() places the message id of the request in *msgidp. A subsequent call to ldap_result() can be used to obtain the result of the delete.

Similar to ldap_delete_ext(), the ldap_delete() function initiates an asynchronous delete operation and returns the message id of the operation initiated. As for ldap_delete_ext(), a subsequent call to ldap_result() can be used to obtain the result of the delete. In case of error, ldap_delete() will return -1, setting the session error parameters in the LDAP structure appropriately.

The synchronous ldap_delete_ext_s() and ldap_delete_s() functions both return the result of the operation, either the constant LDAP_SUCCESS if the operation was successful, or another LDAP error code if it was not.

The ldap_delete_ext() and ldap_delete_ext_s() functions support LDAPv3 server controls and client controls.

See Also:

"Handling Errors and Parsing Results" for more information about possible errors and how to interpret them

Syntax

int ldap_delete_ext
(

LDAP            *ld,
const char      *dn,
LDAPControl     **serverctrls,
LDAPControl     **clientctrls,
int             *msgidp

);

int ldap_delete_ext_s
(
LDAP            *ld,

const char      *dn,
LDAPControl     **serverctrls,
LDAPControl     **clientctrls

);

int ldap_delete

LDAP            *ld,
const char      *dn

);

int ldap_delete_s
(

LDAP            *ld,
const char      *dn

);

Parameters

Table 11-17 lists and describes the parameters for delete operations.

Table 11-17 Parameters for Delete Operations

Parameter	Description
ld	The session handle.
dn	The name of the entry to delete.
serverctrls	List of LDAP server controls.
clientctrls	List of client controls.
msgidp	This result parameter will be set to the message id of the request if the `ldap_delete_ext()` call succeeds.

Usage Notes

Note that the entry to delete must be a leaf entry—that is, it must have no children. Deletion of entire subtrees in a single operation is not supported by LDAP.

11.2.9.9 ldap_extended_operation and ldap_extended_operation_s

These routines enable extended LDAP operations to be passed to the server, providing a general protocol extensibility mechanism.

The ldap_extended_operation()function initiates an asynchronous extended operation and returns the constant LDAP_SUCCESS if the request was successfully sent, or another LDAP error code if not. If successful, ldap_extended_operation() places the message id of the request in *msgidp. A subsequent call to ldap_result() can be used to obtain the result of the extended operation which can be passed to ldap_parse_extended_result() to obtain the object identifier (OID) and data contained in the response.

The synchronous ldap_extended_operation_s() function returns the result of the operation, either the constant LDAP_SUCCESS if the operation was successful, or another LDAP error code if it was not. The retoid and retdata parameters are filled in with the OID and data from the response. If no OID or data was returned, these parameters are set to NULL.

The ldap_extended_operation() and ldap_extended_operation_s() functions both support LDAPv3 server controls and client controls.

See Also:

"Handling Errors and Parsing Results" for more information about possible errors and how to interpret them

Syntax

int ldap_extended_operation
(

LDAP                    *ld,
const char              *requestoid,
const struct berval     *requestdata,
LDAPControl             **serverctrls,
LDAPControl             **clientctrls,
int                     *msgidp

);

int ldap_extended_operation_s
(

LDAP                    *ld,
const char              *requestoid,
const struct berval     *requestdata,
LDAPControl             **serverctrls,
LDAPControl             **clientctrls,
char                    **retoidp,
struct berval           **retdatap

);

Parameters

Table 11-18 lists and describes the parameters for extended operations.

Table 11-18 Parameters for Extended Operations

Parameter	Description
ld	The session handle
requestoid	The dotted-OID text string naming the request
requestdata	The arbitrary data needed by the operation (if `NULL`, no data is sent to the server)
serverctrls	List of LDAP server controls
clientctrls	List of client controls
msgidp	This result parameter will be set to the message id of the request if the `ldap_extended_operation()` call succeeds.
retoidp	Pointer to a character string that will be set to an allocated, dotted-OID text string returned by the server. This string should be disposed of using the `ldap_memfree()` function. If no OID was returned, `*retoidp` is set to `NULL`.
retdatap	Pointer to a `berval` structure pointer that will be set an allocated copy of the data returned by the server. This `struct berval` should be disposed of using `ber_bvfree()`. If no data is returned, `*retdatap` is set to `NULL`.

11.2.10 Abandoning an Operation

Use the functions in this section to abandon an operation in progress:

11.2.10.1 ldap_abandon_ext and ldap_abandon

ldap_abandon_ext() abandons the operation with message id msgid and returns the constant LDAP_SUCCESS if the abandon was successful or another LDAP error code if not.

ldap_abandon() is identical to ldap_abandon_ext() except that it does not accept client or server controls and it returns zero if the abandon was successful, -1 otherwise.

After a successful call to ldap_abandon() or ldap_abandon_ext(), results with the given message id are never returned from a subsequent call to ldap_result(). There is no server response to LDAP abandon operations.

Syntax

int ldap_abandon_ext
(

LDAP            *ld,
int             msgid,
LDAPControl     **serverctrls,
LDAPControl     **clientctrls

);

int ldap_abandon
(

LDAP            *ld,
int             msgid

);

Parameters

Table 11-19 lists and describes the parameters for abandoning an operation.

Table 11-19 Parameters for Abandoning an Operation

Parameter	Description
ld	The session handle.
msgid	The message id of the request to be abandoned.
serverctrls	List of LDAP server controls.
clientctrls	List of client controls.

See Also:

"Handling Errors and Parsing Results" for more information about possible errors and how to interpret them

11.2.11 Obtaining Results and Peeking Inside LDAP Messages

Use the functions in this section to return the result of an operation initiated asynchronously. They identify messages by type and by ID.

11.2.11.1 ldap_result, ldap_msgtype, and ldap_msgid

ldap_result() is used to obtain the result of a previous asynchronously initiated operation. Note that depending on how it is called, ldap_result() can actually return a list or "chain" of result messages. The ldap_result() function only returns messages for a single request, so for all LDAP operations other than search only one result message is expected; that is, the only time the "result chain" can contain more than one message is if results from a search operation are returned.

Once a chain of messages has been returned to the caller, it is no longer tied in any caller-visible way to the LDAP request that produced it. Therefore, a chain of messages returned by calling ldap_result() or by calling a synchronous search routine will never be affected by subsequent LDAP API calls (except for ldap_msgfree() which is used to dispose of a chain of messages).

ldap_msgfree() frees the result messages (possibly an entire chain of messages) obtained from a previous call to ldap_result() or from a call to a synchronous search routine.

ldap_msgtype() returns the type of an LDAP message. ldap_msgid() returns the message ID of an LDAP message.

Syntax

int ldap_result
(

LDAP            *ld,
int             msgid,
int             all,
struct timeval  *timeout,
LDAPMessage     **res

);
int ldap_msgfree( LDAPMessage *res );
int ldap_msgtype( LDAPMessage *res );
int ldap_msgid( LDAPMessage *res );

Parameters

Table 11-20 lists and describes the parameters for obtaining results and peeling inside LDAP messages.

Table 11-20 Parameters for Obtaining Results and Peeking Inside LDAP Messages

Parameter	Description
ld	The session handle.
msgid	The message id of the operation whose results are to be returned, the constant `LDAP_RES_UNSOLICITED (0)` if an unsolicited result is desired, or the constant `LDAP_RES_ANY (-1)` if any result is desired.
all	Specifies how many messages will be retrieved in a single call to `ldap_result()`. This parameter only has meaning for search results. Pass the constant `LDAP_MSG_ONE (0x00)` to retrieve one message at a time. Pass `LDAP_MSG_ALL (0x01)` to request that all results of a search be received before returning all results in a single chain. Pass `LDAP_MSG_RECEIVED (0x02)` to indicate that all messages retrieved so far are to be returned in the result chain.
timeout	A timeout specifying how long to wait for results to be returned. A `NULL` value causes `ldap_result()` to block until results are available. A timeout value of zero seconds specifies a polling behavior.
res	For `ldap_result()`, a result parameter that will contain the result of the operation. If no results are returned, `*res` is set to `NULL`. For `ldap_msgfree()`, the result chain to be freed, obtained from a previous call to `ldap_result()`, `ldap_search_s()`, or `ldap_search_st()`. If `res` is `NULL`, nothing is done and `ldap_msgfree()` returns zero.

Usage Notes

Upon successful completion, ldap_result() returns the type of the first result returned in the res parameter. This will be one of the following constants.

LDAP_RES_BIND (0x61)

LDAP_RES_SEARCH_ENTRY (0x64)

LDAP_RES_SEARCH_REFERENCE (0x73)-- new in LDAPv3

LDAP_RES_SEARCH_RESULT (0x65)

LDAP_RES_MODIFY (0x67)

LDAP_RES_ADD (0x69)

LDAP_RES_DELETE (0x6B)

LDAP_RES_MODDN (0x6D)

LDAP_RES_COMPARE (0x6F)

LDAP_RES_EXTENDED (0x78) -- new in LDAPv3

ldap_result() returns 0 if the timeout expired and -1 if an error occurs, in which case the error parameters of the LDAP session handle will be set accordingly.

ldap_msgfree() frees each message in the result chain pointed to by res and returns the type of the last message in the chain. If res is NULL, then nothing is done and the value zero is returned.

ldap_msgtype() returns the type of the LDAP message it is passed as a parameter. The type will be one of the types listed previously, or -1 on error.

ldap_msgid() returns the message ID associated with the LDAP message passed as a parameter, or -1 on error.

11.2.12 Handling Errors and Parsing Results

Use the functions in this section to extract information from results and to handle errors returned by other LDAP API routines.

11.2.12.1 ldap_parse_result, ldap_parse_sasl_bind_result, ldap_parse_extended_result, and ldap_err2string

Note that ldap_parse_sasl_bind_result() and ldap_parse_extended_result() must typically be used in addition to ldap_parse_result() to retrieve all the result information from SASL Bind and Extended Operations respectively.

The ldap_parse_result(), ldap_parse_sasl_bind_result(), and ldap_parse_extended_result() functions all skip over messages of type LDAP_RES_SEARCH_ENTRY and LDAP_RES_SEARCH_REFERENCE when looking for a result message to parse. They return the constant LDAP_SUCCESS if the result was successfully parsed and another LDAP error code if not. Note that the LDAP error code that indicates the outcome of the operation performed by the server is placed in the errcodep ldap_parse_result() parameter. If a chain of messages that contains more than one result message is passed to these routines they always operate on the first result in the chain.

ldap_err2string() is used to convert a numeric LDAP error code, as returned by ldap_parse_result(), ldap_parse_sasl_bind_result(), ldap_parse_extended_result() or one of the synchronous API operation calls, into an informative zero-terminated character string message describing the error. It returns a pointer to static data.

Syntax

int ldap_parse_result
(

LDAP            *ld,
LDAPMessage     *res,
int             *errcodep,
char            **matcheddnp,
char            **errmsgp,
char            ***referralsp,
LDAPControl     ***serverctrlsp,
int             freeit

);

int ldap_parse_sasl_bind_result
(

LDAP            *ld,
LDAPMessage     *res,
struct berval   **servercredp,
int             freeit

);

int ldap_parse_extended_result
(

LDAP            *ld,
LDAPMessage     *res,
char            **retoidp,
struct berval   **retdatap,
int             freeit

);
#define LDAP_NOTICE_OF_DISCONNECTION    "1.3.6.1.4.1.1466.20036"
char *ldap_err2string( int err );

The routines immediately following are deprecated. To learn more about them, see RFC 1823.

int ldap_result2error
(

LDAP            *ld,
LDAPMessage     *res,
int             freeit

);
void ldap_perror( LDAP *ld, const char *msg );

Parameters

Table 11-21 lists and describes parameters for handling errors and parsing results.

Table 11-21 Parameters for Handling Errors and Parsing Results

Parameter	Description
ld	The session handle.
res	The result of an LDAP operation as returned by `ldap_result()` or one of the synchronous API operation calls.
errcodep	This result parameter will be filled in with the LDAP error code field from the `LDAPMessage` message. This is the indication from the server of the outcome of the operation. `NULL` should be passed to ignore this field.
matcheddnp	In the case of a return of `LDAP_NO_SUCH_OBJECT`, this result parameter will be filled in with a DN indicating how much of the name in the request was recognized. `NULL` should be passed to ignore this field. The matched DN string should be freed by calling `ldap_memfree()` which is described later in this document.
errmsgp	This result parameter will be filled in with the contents of the error message field from the `LDAPMessage` message. The error message string should be freed by calling `ldap_memfree()` which is described later in this document. `NULL` should be passed to ignore this field.
referralsp	This result parameter will be filled in with the contents of the referrals field from the `LDAPMessage` message, indicating zero or more alternate LDAP servers where the request is to be retried. The referrals array should be freed by calling `ldap_value_free()` which is described later in this document. `NULL` should be passed to ignore this field.
serverctrlsp	This result parameter will be filled in with an allocated array of controls copied out of the `LDAPMessage` message. The control array should be freed by calling `ldap_controls_free()` which was described earlier.
freeit	A Boolean that determines whether the `res` parameter is disposed of or not. Pass any nonzero value to have these routines free `res` after extracting the requested information. This is provided as a convenience; you can also use `ldap_msgfree()` to free the result later. If `freeit` is nonzero, the entire chain of messages represented by res is disposed of.
servercredp	For SASL bind results, this result parameter will be filled in with the credentials passed back by the server for mutual authentication, if given. An allocated `berval` structure is returned that should be disposed of by calling `ber_bvfree()`. `NULL` should be passed to ignore this field.
retoidp	For extended results, this result parameter will be filled in with the dotted-OID text representation of the name of the extended operation response. This string should be disposed of by calling `ldap_memfree()`. `NULL` should be passed to ignore this field. The `LDAP_NOTICE_OF_DISCONNECTION` macro is defined as a convenience for clients that wish to check an OID to see if it matches the one used for the unsolicited Notice of Disconnection (defined in RFC 2251[2] section 4.4.1).
retdatap	For extended results, this result parameter will be filled in with a pointer to a `struct berval` containing the data in the extended operation response. It should be disposed of by calling `ber_bvfree()`. `NULL` should be passed to ignore this field.
err	For `ldap_err2string()`, an LDAP error code, as returned by `ldap_parse_result()` or another LDAP API call.

Usage Notes

See RFC 1823 for a description of parameters peculiar to the deprecated routines.

11.2.13 Stepping Through a List of Results

Use the routines in this section to step through the list of messages in a result chain returned by ldap_result().

11.2.13.1 ldap_first_message and ldap_next_message

The result chain for search operations can include referral messages, entry messages, and result messages.

ldap_count_messages() is used to count the number of messages returned. The ldap_msgtype() function, described previously, can be used to distinguish between the different message types.

LDAPMessage *ldap_first_message( LDAP *ld, LDAPMessage *res );
LDAPMessage *ldap_next_message( LDAP *ld, LDAPMessage *msg );
int ldap_count_messages( LDAP *ld, LDAPMessage *res );

Parameters

Table 11-22 lists and describes the parameters for stepping through a list of results.

Table 11-22 Parameters for Stepping Through a List of Results

Parameter	Description
ld	The session handle.
res	The result chain, as obtained by a call to one of the synchronous search routines or `ldap_result()`.
msg	The message returned by a previous call to `ldap_first_message()` or `ldap_next_message()`.

Usage Notes

ldap_first_message() and ldap_next_message() will return NULL when no more messages exist in the result set to be returned. NULL is also returned if an error occurs while stepping through the entries, in which case the error parameters in the session handle ld will be set to indicate the error.

If successful, ldap_count_messages() returns the number of messages contained in a chain of results; if an error occurs such as the res parameter being invalid, -1 is returned. The ldap_count_messages() call can also be used to count the number of messages that remain in a chain if called with a message, entry, or reference returned by ldap_first_message(), ldap_next_message(), ldap_first_entry(), ldap_next_entry(), ldap_first_reference(), ldap_next_reference().

11.2.14 Parsing Search Results

Use the functions in this section to parse the entries and references returned by ldap_search functions. These results are returned in an opaque structure that may be accessed by calling the routines described in this section. Routines are provided to step through the entries and references returned, step through the attributes of an entry, retrieve the name of an entry, and retrieve the values associated with a given attribute in an entry.

11.2.14.1 ldap_first_entry, ldap_next_entry, ldap_first_reference, ldap_next_reference, ldap_count_entries, and ldap_count_references

The ldap_first_entry() and ldap_next_entry() routines are used to step through and retrieve the list of entries from a search result chain. The ldap_first_reference() and ldap_next_reference() routines are used to step through and retrieve the list of continuation references from a search result chain. ldap_count_entries() is used to count the number of entries returned. ldap_count_references() is used to count the number of references returned.

LDAPMessage *ldap_first_entry( LDAP *ld, LDAPMessage *res );
LDAPMessage *ldap_next_entry( LDAP *ld, LDAPMessage *entry );
LDAPMessage *ldap_first_reference( LDAP *ld, LDAPMessage *res );
LDAPMessage *ldap_next_reference( LDAP *ld, LDAPMessage *ref );
int ldap_count_entries( LDAP *ld, LDAPMessage *res );
int ldap_count_references( LDAP *ld, LDAPMessage *res );

Parameters

Table 11-23 lists and describes the parameters or retrieving entries and continuation references from a search result chain, and for counting entries returned.

Table 11-23 Parameters for Retrieving Entries and Continuation References from a Search Result Chain, and for Counting Entries Returned

Parameter	Description
ld	The session handle.
res	The search result, as obtained by a call to one of the synchronous search routines or `ldap_result()`.
entry	The entry returned by a previous call to `ldap_first_entry()` or `ldap_next_entry()`.
ref	The reference returned by a previous call to `ldap_first_reference()` or `ldap_next_reference()`.

Usage Notes

ldap_first_entry(), ldap_next_entry(), ldap_first_reference(), and ldap_next_reference() all return NULL when no more entries or references exist in the result set to be returned. NULL is also returned if an error occurs while stepping through the entries or references, in which case the error parameters in the session handle ld will be set to indicate the error.

ldap_count_entries() returns the number of entries contained in a chain of entries; if an error occurs such as the res parameter being invalid, -1 is returned. The ldap_count_entries() call can also be used to count the number of entries that remain in a chain if called with a message, entry or reference returned by ldap_first_message(), ldap_next_message(), ldap_first_entry(), ldap_next_entry(), ldap_first_reference(), ldap_next_reference().

ldap_count_references() returns the number of references contained in a chain of search results; if an error occurs such as the res parameter being invalid, -1 is returned. The ldap_count_references() call can also be used to count the number of references that remain in a chain.

11.2.14.2 ldap_first_attribute and ldap_next_attribute

Use the functions in this section to step through the list of attribute types returned with an entry.

Syntax

char *ldap_first_attribute
(

LDAP            *ld,
LDAPMessage     *entry,
BerElement      **ptr

);

char *ldap_next_attribute
(

LDAP            *ld,
LDAPMessage     *entry,
BerElement      *ptr

);
void ldap_memfree( char *mem );

Parameters

Table 11-24 lists and describes the parameters for stepping through attribute types returned with an entry.

Table 11-24 Parameters for Stepping Through Attribute Types Returned with an Entry

Parameter	Description
ld	The session handle.
entry	The entry whose attributes are to be stepped through, as returned by `ldap_first_entry()` or `ldap_next_entry()`.
ptr	In `ldap_first_attribute()`, the address of a pointer used internally to keep track of the current position in the entry. In `ldap_next_attribute()`, the pointer returned by a previous call to `ldap_first_attribute()`. The `BerElement` type itself is an opaque structure.
mem	A pointer to memory allocated by the LDAP library, such as the attribute type names returned by `ldap_first_attribute()` and `ldap_next_attribute`, or the DN returned by `ldap_get_dn()`. If `mem` is `NULL`, the `ldap_memfree()` call does nothing.

Usage Notes

ldap_first_attribute() and ldap_next_attribute() returns NULL when the end of the attributes is reached, or if there is an error. In the latter case, the error parameters in the session handle ld are set to indicate the error.

Both routines return a pointer to an allocated buffer containing the current attribute name. This should be freed when no longer in use by calling ldap_memfree().

ldap_first_attribute() will allocate and return in ptr a pointer to a BerElement used to keep track of the current position. This pointer may be passed in subsequent calls to ldap_next_attribute() to step through the entry's attributes. After a set of calls to ldap_first_attribute() and ldap_next_attribute(), if ptr is non-null, it should be freed by calling ber_free(ptr, 0). Note that it is very important to pass the second parameter as 0 (zero) in this call, since the buffer associated with the BerElement does not point to separately allocated memory.

The attribute type names returned are suitable for passing in a call to ldap_get_values() and friends to retrieve the associated values.

11.2.14.3 ldap_get_values, ldap_get_values_len, ldap_count_values, ldap_count_values_len, ldap_value_free, and ldap_value_free_len

ldap_get_values() and ldap_get_values_len() are used to retrieve the values of a given attribute from an entry. ldap_count_values() and ldap_count_values_len() are used to count the returned values.

ldap_value_free() and ldap_value_free_len() are used to free the values.

Syntax

char **ldap_get_values
(

LDAP            *ld,
LDAPMessage     *entry,
const char      *attr

);

struct berval **ldap_get_values_len
(

LDAP            *ld,
LDAPMessage     *entry,
const char      *attr

);

int ldap_count_values( char **vals );
int ldap_count_values_len( struct berval **vals );
void ldap_value_free( char **vals );
void ldap_value_free_len( struct berval **vals );

Parameters

Table 11-25 lists and describes the parameters for retrieving and counting attribute values.

Table 11-25 Parameters for Retrieving and Counting Attribute Values

Parameter	Description
ld	The session handle.
entry	The entry from which to retrieve values, as returned by `ldap_first_entry()` or `ldap_next_entry()`.
attr	The attribute whose values are to be retrieved, as returned by `ldap_first_attribute()` or `ldap_next_attribute()`, or a caller-supplied string (for example, "mail").
vals	The values returned by a previous call to `ldap_get_values()` or `ldap_get_values_len()`.

Usage Notes

Two forms of the various calls are provided. The first form is only suitable for use with non-binary character string data. The second _len form is used with any kind of data.

ldap_get_values() and ldap_get_values_len() return NULL if no values are found for attr or if an error occurs.

ldap_count_values() and ldap_count_values_len() return -1 if an error occurs such as the vals parameter being invalid.

If a NULL vals parameter is passed to ldap_value_free() or ldap_value_free_len(), nothing is done.

Note that the values returned are dynamically allocated and should be freed by calling either ldap_value_free() or ldap_value_free_len() when no longer in use.

11.2.14.4 ldap_get_dn, ldap_explode_dn, ldap_explode_rdn, and ldap_dn2ufn

ldap_get_dn() is used to retrieve the name of an entry. ldap_explode_dn() and ldap_explode_rdn() are used to break up a name into its component parts. ldap_dn2ufn() is used to convert the name into a more user friendly format.

Syntax

char *ldap_get_dn( LDAP *ld, LDAPMessage *entry );
char **ldap_explode_dn( const char *dn, int notypes );
char **ldap_explode_rdn( const char *rdn, int notypes );
char *ldap_dn2ufn( const char *dn );

Parameters

Table 11-26 lists and describes the parameters for retrieving, exploding, and converting entry names.

Table 11-26 Parameters for Retrieving, Exploding, and Converting Entry Names

Parameter	Description
ld	The session handle.
entry	The entry whose name is to be retrieved, as returned by `ldap_first_entry()` or `ldap_next_entry()`.
dn	The DN to explode, such as returned by `ldap_get_dn()`.
rdn	The RDN to explode, such as returned in the components of the array returned by `ldap_explode_dn()`.
notypes	A Boolean parameter, if nonzero indicating that the DN or RDN components are to have their type information stripped off: `cn=Babs` would become `Babs`.

Usage Notes

ldap_get_dn() returns NULL if a DN parsing error occurs. The function sets error parameters in the session handle ld to indicate the error. It returns a pointer to newly allocated space that the caller should free by calling ldap_memfree() when it is no longer in use.

ldap_explode_dn() returns a NULL-terminated char * array containing the RDN components of the DN supplied, with or without types as indicated by the notypes parameter. The components are returned in the order they appear in the DN. The array returned should be freed when it is no longer in use by calling ldap_value_free().

ldap_explode_rdn() returns a NULL-terminated char * array containing the components of the RDN supplied, with or without types as indicated by the notypes parameter. The components are returned in the order they appear in the rdn. The array returned should be freed when it is no longer in use by calling ldap_value_free().

ldap_dn2ufn() converts the DN into a user friendly format. The UFN returned is newly allocated space that should be freed by a call to ldap_memfree() when no longer in use.

11.2.14.5 ldap_get_entry_controls

ldap_get_entry_controls() is used to extract LDAP controls from an entry.

Syntax

int ldap_get_entry_controls
(

LDAP            *ld,
LDAPMessage     *entry,
LDAPControl     ***serverctrlsp

);

Parameters

Table 11-27 lists and describes the parameters for extracting LDAP control from an entry.

Table 11-27 Parameters for Extracting LDAP Controls from an Entry

Parameters	Description
ld	The session handle.
entry	The entry to extract controls from, as returned by `ldap_first_entry()` or `ldap_next_entry()`.
serverctrlsp	This result parameter will be filled in with an allocated array of controls copied out of entry. The control array should be freed by calling `ldap_controls_free()`. If `serverctrlsp` is `NULL`, no controls are returned.

Usage Notes

ldap_get_entry_controls() returns an LDAP error code that indicates whether the reference could be successfully parsed (LDAP_SUCCESS if all goes well).

11.2.14.6 ldap_parse_reference

Use ldap_parse_reference() to extract referrals and controls from a SearchResultReference message.

Syntax

int ldap_parse_reference
(

LDAP            *ld,
LDAPMessage     *ref,
char            ***referralsp,
LDAPControl     ***serverctrlsp,
int             freeit

);

Parameters

Table 11-28 lists and describes parameters for extracting referrals and controls from a SearchResultReference message.

Table 11-28 Parameters for Extracting Referrals and Controls from a SearchResultReference Message

Parameter	Description
ld	The session handle.
ref	The reference to parse, as returned by `ldap_result()`, `ldap_first_reference()`, or `ldap_next_reference()`.
referralsp	This result parameter will be filled in with an allocated array of character strings. The elements of the array are the referrals (typically LDAP URLs) contained in ref. The array should be freed when no longer in used by calling `ldap_value_free()`. If `referralsp` is `NULL`, the referral URLs are not returned.
serverctrlsp	This result parameter will be filled in with an allocated array of controls copied out of `ref`. The control array shouldbe freed by calling `ldap_controls_free()`. If `serverctrlsp` is `NULL`, no controls are returned.
freeit	A Boolean that determines whether the `ref` parameter is disposed of or not. Pass any nonzero value to have this routine free `ref` after extracting the requested information. This is provided as a convenience. You can also use `ldap_msgfree()` to free the result later.

Usage Notes

ldap_parse_reference() returns an LDAP error code that indicates whether the reference could be successfully parsed (LDAP_SUCCESS if all goes well).

11.3 S ample C API Usage

The following examples show how to use the C API both with and without SSL and for SASL authentication. More complete examples are given in RFC 1823. The sample code for the command-line tool to perform an LDAP search also demonstrates use of the API in both the SSL and the non-SSL mode.

This section contains these topics:

C API Usage with SSL
C API Usage Without SSL
C API Usage for SASL-Based DIGEST-MD5 Authentication

11.3.1 C API Usage with SSL

#include <stdio.h>
#include <ldap.h>

main()
{

LDAP          *ld;
int 	          ret = 0;
….
/* open a connection */
if ((ld = ldap_open("MyHost", 636)) == NULL)
     exit( 1 );

/* SSL initialization */  
ret = ldap_init_SSL(&ld->ld_sb, "file:/sslwallet", "welcome", 
                                        GSLC_SSL_ONEWAY_AUTH );
if(ret != 0) 
{

printf(" %s \n", ldap_err2string(ret));
exit(1);

}

/* authenticate as nobody */
if ( ldap_bind_s( ld, NULL, NULL ) != LDAP_SUCCESS ) {
     ldap_perror( ld, "ldap_bind_s" );
     exit( 1 );
}

.
.
.

Because the user is making the ldap_init_SSL call, the client/server communication in the previous example is secured by using SSL.

11.3.2 C API Usage Without SSL

#include <stdio.h>
#include <ldap.h>

main()
{

LDAP          *ld;
int           ret = 0;
.
.
.
/* open a connection */
if ( (ld = ldap_open( "MyHost", LDAP_PORT )) == NULL )
     exit( 1 );

/* authenticate as nobody */
if ( ldap_bind_s( ld, NULL, NULL ) != LDAP_SUCCESS ) {
     ldap_perror( ld, "ldap_bind_s" );
      exit( 1 );
}
.
.
.

In the previous example, the user is not making the ldap_init_SSL call, and the client-to-server communication is therefore not secure.

11.3.3 C API Usage for SASL-Based DIGEST-MD5 Authentication

This sample program illustrates the usage of LDAP SASL C-API for SASL-based DIGEST-MD5 authentication to a directory server.

/*
   EXPORT FUNCTION(S)
     NONE

   INTERNAL FUNCTION(S)
     NONE

   STATIC FUNCTION(S)
     NONE

   NOTES
     Usage:
      saslbind -h ldap_host -p ldap_port -D authentication_identity_dn \
               -w password  
      options 
       -h     LDAP host
       -p     LDAP port
       -D     DN of the identity for authentication
       -p     Password

       Default SASL authentication parameters used by the demo program
       SASL Security Property :    Currently only "auth" security property 
                                   is supported by the C-API. This demo
                                   program uses this security property.
       SASL Mechanism         :    Supported mechanisms by OID
                                   "DIGEST-MD5" - This demo program 
                                                  illustrates it's usage.
                                   "EXTERNAL" - SSL authentication is used.
                                                (This demo program does 
                                                 not illustrate it's usage.)
       Authorization identity :    This demo program does not use any
                                    authorization identity.

   MODIFIED   (MM/DD/YY)
   ******      06/12/03 - Creation

*/

/*---------------------------------------------------------------------------
                     PRIVATE TYPES AND CONSTANTS
  ---------------------------------------------------------------------------*/
                
/*---------------------------------------------------------------------------
                     STATIC FUNCTION DECLARATIONS 
  ---------------------------------------------------------------------------*/

#include <stdio.h>
#include <stdlib.h>
#include <ldap.h>


static int ldap_version = LDAP_VERSION3;

main (int argc, char **argv)
{
  LDAP*           ld;
  extern char*    optarg;
  char*           ldap_host = NULL;
  char*           ldap_bind_dn = NULL;
  char*           ldap_bind_pw = NULL;
  int             authmethod = 0;
  char            ldap_local_host[256] = "localhost";
  int             ldap_port = 389;
  char*           authcid = (char *)NULL;
  char*           mech = "DIGEST-MD5"; /* SASL mechanism */
  char*           authzid = (char *)NULL;
  char*           sasl_secprops = "auth";
  char*           realm = (char *)NULL;
  int             status = LDAP_SUCCESS;
  OraLdapHandle   sasl_cred = (OraLdapHandle )NULL;
  OraLdapClientCtx *cctx = (OraLdapClientCtx *)NULL;
  int              i = 0;


    while (( i = getopt( argc, argv,
	    "D:h:p:w:E:P:U:V:W:O:R:X:Y:Z"
	    )) != EOF ) {
	switch( i ) {

	case 'h':	/* ldap host */
	    ldap_host = (char *)strdup( optarg );
	    break;
	case 'D':	/* bind DN */
	    authcid = (char *)strdup( optarg );
	    break;
	    
	case 'p':	/* ldap port */
	    ldap_port = atoi( optarg );
	    break;
	case 'w':	/* Password */
	    ldap_bind_pw = (char *)strdup( optarg );
	    break;

    default:
	    printf("Invalid Arguments passed\n" );
	}
    }


  /* Get the connection to the LDAP server */
  if (ldap_host == NULL)
    ldap_host = ldap_local_host;

  if ((ld = ldap_open (ldap_host, ldap_port)) == NULL)
  {
    ldap_perror (ld, "ldap_init");
    exit (1);
  }

  /* Create the client context needed by LDAP C-API Oracle Extension functions*/
  status = ora_ldap_init_clientctx(&cctx);

  if(LDAP_SUCCESS != status) {
     printf("Failed during creation of client context \n");
     exit(1);
  }

  /* Create SASL credentials */
  sasl_cred = ora_ldap_create_cred_hdl(cctx, ORA_LDAP_CRED_HANDLE_SASL_MD5);

  ora_ldap_set_cred_props(cctx, sasl_cred, ORA_LDAP_CRED_SASL_REALM, 
      (void *)realm);
  ora_ldap_set_cred_props(cctx, sasl_cred, ORA_LDAP_CRED_SASL_AUTH_PASSWORD, 
      (void *)ldap_bind_pw);
  ora_ldap_set_cred_props(cctx, sasl_cred, ORA_LDAP_CRED_SASL_AUTHORIZATION_ID,
      (void *)authzid);
  ora_ldap_set_cred_props(cctx, sasl_cred, ORA_LDAP_CRED_SASL_SECURITY_PROPERTIES, 
      (void *)sasl_secprops);

  /* If connecting to the directory using SASL DIGEST-MD5, the Authentication ID 
     has to be normalized before it's sent to the server,
     the LDAP C-API does this normalization based on the following flag set in
     SASL credential properties */
  ora_ldap_set_cred_props(cctx, sasl_cred, ORA_LDAP_CRED_SASL_NORM_AUTHDN, (void *)NULL);
  
  /* SASL Authetication to LDAP Server */
  status = (int)ora_ldap_init_SASL(cctx, ld, (char *)authcid, (char *)ORA_LDAP_SASL_MECH_DIGEST_MD5,
				     sasl_cred, NULL, NULL);

  if(LDAP_SUCCESS == status) {
     printf("SASL bind successful \n" );
  }else {
     printf("SASL bind failed with status :  %d\n", status);
  }

  /* Free SASL Credentials */
  ora_ldap_free_cred_hdl(cctx, sasl_cred);

  status = ora_ldap_free_clientctx(cctx);

  /* Unbind from LDAP server */
  ldap_unbind (ld);

  return (0);
}


/* end of file saslbind.c */

11.4 Required Header Files and Libraries for the C API

To build applications with the C API, you need to:

Include the header file located at $ORACLE_HOME/ldap/public/ldap.h.
Dynamically link to the library located at
- $ORACLE_HOME/lib/libclntsh.so.10.1 on UNIX operating systems
- %ORACLE_HOME%\bin\oraldapclnt10.dll on Windows operating systems

11.5 Dependencies and Limitations of the C API

This API can work against any release of Oracle Internet Directory. It requires either an Oracle environment or, at minimum, globalization support and other core libraries.

To use the different authentication modes in SSL, the directory server requires corresponding configuration settings.

See Also:

Oracle Internet Directory Administrator's Guide for details about how to set the directory server in various SSL authentication modes

Oracle Wallet Manager is required for creating wallets if you are using the C API in SSL mode.

TCP/IP Socket Library is required.

The following Oracle libraries are required:

Oracle SSL-related libraries
Oracle system libraries

Sample libraries are included in the release for the sample command line tool. You should replace these libraries with your own versions of the libraries.

The product supports only those authentication mechanisms described in LDAP SDK specifications (RFC 1823).

11 C API Reference

11.1 About the Oracle Internet Directory C API

11.1.1 Oracle Internet Directory SDK C API SSL Extensions

11.1.1.1 SSL Interface Calls

11.1.1.2 Wallet Support

11.2 Functions in the C API

11.2.1 The Functions at a Glance

11.2.2 Initializing an LDAP Session

11.2.2.1 ldap_init and ldap_open

11.2.3 LDAP Session Handle Options

11.2.3.1 ldap_get_option and ldap_set_option

11.2.4 Authenticating to the Directory

11.2.4.1 ldap_sasl_bind, ldap_sasl_bind_s, ldap_simple_bind, and ldap_simple_bind_s

11.2.5 SASL Authentication Using Oracle Extensions

11.2.5.1 ora_ldap_create_cred_hdl, ora_ldap_set_cred_props, ora_ldap_get_cred_props, and ora_ldap_free_cred_hdl

11.2.6 SASL Authentication

11.2.6.1 ora_ldap_init_SASL

11.2.7 Working With Controls

11.2.8 Closing the Session

11.2.8.1 ldap_unbind, ldap_unbind_ext, and ldap_unbind_s

11.2.9 Performing LDAP Operations

11.2.9.1 ldap_search_ext, ldap_search_ext_s, ldap_search, and ldap_search_s

11.2.9.2 Reading an Entry

11.2.9.3 Listing the Children of an Entry

11.2.9.4 ldap_compare_ext, ldap_compare_ext_s, ldap_compare, and ldap_compare_s

11.2.9.5 ldap_modify_ext, ldap_modify_ext_s, ldap_modify, and ldap_modify_s

11.2.9.6 ldap_rename and ldap_rename_s

11.2.9.7 ldap_add_ext, ldap_add_ext_s, ldap_add, and ldap_add_s

11.2.9.8 ldap_delete_ext, ldap_delete_ext_s, ldap_delete, and ldap_delete_s

11.2.9.9 ldap_extended_operation and ldap_extended_operation_s

11.2.10 Abandoning an Operation

11.2.10.1 ldap_abandon_ext and ldap_abandon

11.2.11 Obtaining Results and Peeking Inside LDAP Messages

11.2.11.1 ldap_result, ldap_msgtype, and ldap_msgid

11.2.12 Handling Errors and Parsing Results

11.2.12.1 ldap_parse_result, ldap_parse_sasl_bind_result, ldap_parse_extended_result, and ldap_err2string

11.2.13 Stepping Through a List of Results

11.2.13.1 ldap_first_message and ldap_next_message

11.2.14 Parsing Search Results

11.2.14.1 ldap_first_entry, ldap_next_entry, ldap_first_reference, ldap_next_reference, ldap_count_entries, and ldap_count_references

11.2.14.2 ldap_first_attribute and ldap_next_attribute

11.2.14.3 ldap_get_values, ldap_get_values_len, ldap_count_values, ldap_count_values_len, ldap_value_free, and ldap_value_free_len

11.2.14.4 ldap_get_dn, ldap_explode_dn, ldap_explode_rdn, and ldap_dn2ufn

11.2.14.5 ldap_get_entry_controls

11.2.14.6 ldap_parse_reference

11.3 Sample C API Usage

11.3.1 C API Usage with SSL

11.3.2 C API Usage Without SSL

11.3.3 C API Usage for SASL-Based DIGEST-MD5 Authentication

11.4 Required Header Files and Libraries for the C API

11.5 Dependencies and Limitations of the C API

11.3 S ample C API Usage