1LDAP_BIND(3) Library Functions Manual LDAP_BIND(3)
2
6 ldap_bind, ldap_bind_s, ldap_simple_bind, ldap_simple_bind_s,
7 ldap_sasl_bind, ldap_sasl_bind_s, ldap_sasl_interactive_bind_s,
8 ldap_parse_sasl_bind_result, ldap_unbind, ldap_unbind_s, ldap_un‐
9 bind_ext, ldap_unbind_ext_s, ldap_set_rebind_proc - LDAP bind routines
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12 OpenLDAP LDAP (libldap, -lldap)
13
15 #include <ldap.h>
16 int ldap_bind(LDAP *ld, const char *who, const char *cred,
18 int method);
19 int ldap_bind_s(LDAP *ld, const char *who, const char *cred,
21 int method);
22 int ldap_simple_bind(LDAP *ld, const char *who, const char *passwd);
24 int ldap_simple_bind_s(LDAP *ld, const char *who, const char *passwd);
26 int ldap_sasl_bind(LDAP *ld, const char *dn, const char *mechanism,
28 struct berval *cred, LDAPControl *sctrls[],
29 LDAPControl *cctrls[], int *msgidp);
30 int ldap_sasl_bind_s(LDAP *ld, const char *dn, const char *mechanism,
32 struct berval *cred, LDAPControl *sctrls[],
33 LDAPControl *cctrls[], struct berval **servercredp);
34 int ldap_parse_sasl_bind_result(LDAP *ld, LDAPMessage *res,
36 struct berval **servercredp, int freeit);
37 int ldap_sasl_interactive_bind_s(LDAP *ld, const char *dn,
39 const char *mechs,
40 LDAPControl *sctrls[], LDAPControl *cctrls[],
41 unsigned flags, LDAP_SASL_INTERACT_PROC *interact,
42 void *defaults);
43 int ldap_sasl_interactive_bind(LDAP *ld, const char *dn,
45 const char *mechs,
46 LDAPControl *sctrls[], LDAPControl *cctrls[],
47 unsigned flags, LDAP_SASL_INTERACT_PROC *interact,
48 void *defaults, LDAPMessage *result,
49 const char **rmechp, int *msgidp);
50 int (LDAP_SASL_INTERACT_PROC)(LDAP *ld, unsigned flags, void *defaults, void *sasl_interact);
52 int ldap_unbind(LDAP *ld);
54 int ldap_unbind_s(LDAP *ld);
56 int ldap_unbind_ext(LDAP *ld, LDAPControl *sctrls[],
58 LDAPControl *cctrls[]);
59 int ldap_unbind_ext_s(LDAP *ld, LDAPControl *sctrls[],
61 LDAPControl *cctrls[]);
62 int ldap_set_rebind_proc (LDAP *ld, LDAP_REBIND_PROC *ldap_proc, void *params);
64 int (LDAP_REBIND_PROC)(LDAP *ld, LDAP_CONST char *url, ber_tag_t request, ber_int_t msgid, void *params);
66
68 These routines provide various interfaces to the LDAP bind operation.
69 After an association with an LDAP server is made using ldap_init(3), an
70 LDAP bind operation should be performed before other operations are at‐
71 tempted over the connection. An LDAP bind is required when using Ver‐
72 sion 2 of the LDAP protocol; it is optional for Version 3 but is usu‐
73 ally needed due to security considerations.
74 There are three types of bind calls, ones providing simple authentica‐
76 tion, ones providing SASL authentication, and general routines capable
77 of doing either simple or SASL authentication.
78 SASL (Simple Authentication and Security Layer) can negotiate one of
80 many different kinds of authentication. Both synchronous and asynchro‐
81 nous versions of each variant of the bind call are provided. All rou‐
82 tines take ld as their first parameter, as returned from ldap_init(3).
83
85 The simplest form of the bind call is ldap_simple_bind_s(). It takes
86 the DN to bind as in who, and the userPassword associated with the en‐
87 try in passwd. It returns an LDAP error indication (see ldap_er‐
88 ror(3)). The ldap_simple_bind() call is asynchronous, taking the same
89 parameters but only initiating the bind operation and returning the
90 message id of the request it sent. The result of the operation can be
91 obtained by a subsequent call to ldap_result(3). The
92 ldap_sasl_bind_s() and asynchronous ldap_sasl_bind() functions can also
93 be used to make a simple bind by using LDAP_SASL_SIMPLE as the SASL
94 mechanism.
95
97 The ldap_bind() and ldap_bind_s() routines can be used when the authen‐
98 tication method to use needs to be selected at runtime. They both take
99 an extra method parameter selecting the authentication method to use.
100 It should be set to LDAP_AUTH_SIMPLE to select simple authentication.
101 ldap_bind() returns the message id of the request it initiates.
102 ldap_bind_s() returns an LDAP error indication.
103
105 For SASL binds the server always ignores any provided DN, so the dn pa‐
106 rameter should always be NULL. ldap_sasl_bind_s() sends a single SASL
107 bind request with the given SASL mechanism and credentials in the cred
108 parameter. The format of the credentials depends on the particular SASL
109 mechanism in use. For mechanisms that provide mutual authentication the
110 server's credentials will be returned in the servercredp parameter.
111 The routine returns an LDAP error indication (see ldap_error(3)). The
112 ldap_sasl_bind() call is asynchronous, taking the same parameters but
113 only sending the request and returning the message id of the request it
114 sent. The result of the operation can be obtained by a subsequent call
115 to ldap_result(3). The result must be additionally parsed by
116 ldap_parse_sasl_bind_result() to obtain any server credentials sent
117 from the server.
118 Many SASL mechanisms require multiple message exchanges to perform a
120 complete authentication. Applications should generally use
121 ldap_sasl_interactive_bind_s() rather than calling the basic
122 ldap_sasl_bind() functions directly. The mechs parameter should contain
123 a space-separated list of candidate mechanisms to use. If this parame‐
124 ter is NULL or empty the library will query the supportedSASLMechanisms
125 attribute from the server's rootDSE for the list of SASL mechanisms the
126 server supports. The flags parameter controls the interaction used to
127 retrieve any necessary SASL authentication parameters and should be one
128 of:
129 LDAP_SASL_AUTOMATIC
131 use defaults if available, prompt otherwise
132 LDAP_SASL_INTERACTIVE
134 always prompt
135 LDAP_SASL_QUIET
137 never prompt
138 The interact function uses the provided defaults to handle requests
140 from the SASL library for particular authentication parameters. There
141 is no defined format for the defaults information; it is up to the
142 caller to use whatever format is appropriate for the supplied interact
143 function. The sasl_interact parameter comes from the underlying SASL
144 library. When used with Cyrus SASL this is an array of sasl_interact_t
145 structures. The Cyrus SASL library will prompt for a variety of inputs,
146 including:
147 SASL_CB_GETREALM
149 the realm for the authentication attempt
150 SASL_CB_AUTHNAME
152 the username to authenticate
153 SASL_CB_PASS
155 the password for the provided username
156 SASL_CB_USER
158 the username to use for proxy authorization
159 SASL_CB_NOECHOPROMPT
161 generic prompt for input with input echoing disabled
162 SASL_CB_ECHOPROMPT
164 generic prompt for input with input echoing enabled
165 SASL_CB_LIST_END
167 indicates the end of the array of prompts
168 See the Cyrus SASL documentation for more details.
170 Applications which need to manage connections asynchronously may use
172 ldap_sasl_interactive_bind() instead of the synchronous version. A
173 valid mechs parameter must be supplied, otherwise the library will be
174 forced to query the server for a list of supported mechanisms, and this
175 query will be performed synchronously. The other parameters are the
176 same as for the synchronous function, with three additional parameters.
177 The actual SASL mechanism that was used, and the message ID for use
178 with ldap_result() will be returned in rmechp and msgidp, respectively.
179 The value in rmechp must not be modified by the caller and must be
180 passed back on each subsequent call. The message obtained from ldap_re‐
181 sult() must be passed in the result parameter. This parameter must be
182 NULL when initiating a new Bind. The caller must free the result mes‐
183 sage after each call using ldap_msgfree(). The ldap_sasl_interac‐
184 tive_bind() function returns an LDAP result code. If the code is
185 LDAP_SASL_BIND_IN_PROGRESS then the Bind is not complete yet, and this
186 function must be called again with the next result from the server.
187
189 The ldap_set_rebind_proc function() sets the process to use for binding
190 when an operation returns a referral. This function is used when an ap‐
191 plication needs to bind to another server in order to follow a referral
192 or search continuation reference.
193 The function takes ld, the rebind function, and the params, the arbi‐
195 trary data like state information which the client might need to prop‐
196 erly rebind. The LDAP_OPT_REFERRALS option in the ld must be set to ON
197 for the libraries to use the rebind function. Use the ldap_set_option
198 function to set the value.
199 The rebind function parameters are as follows:
201 The ld parameter must be used by the application when binding to the
203 referred server if the application wants the libraries to follow the
204 referral.
205 The url parameter points to the URL referral string received from the
207 LDAP server. The LDAP application can use the ldap_url_parse(3) func‐
208 tion to parse the string into its components.
209 The request parameter specifies the type of request that generated the
211 referral.
212 The msgid parameter specifies the message ID of the request generating
214 the referral.
215 The params parameter is the same value as passed originally to the
217 ldap_set_rebind_proc() function.
218 The LDAP libraries set all the parameters when they call the rebind
220 function. The application should not attempt to free either the ld or
221 the url structures in the rebind function.
222 The application must supply to the rebind function the required authen‐
224 tication information such as, user name, password, and certificates.
225 The rebind function must use a synchronous bind method.
226
228 The ldap_unbind() call is used to unbind from the directory, terminate
229 the current association, and free the resources contained in the ld
230 structure. Once it is called, the connection to the LDAP server is
231 closed, and the ld structure is invalid. The ldap_unbind_s() call is
232 just another name for ldap_unbind(); both of these calls are synchro‐
233 nous in nature.
234 The ldap_unbind_ext() and ldap_unbind_ext_s() allows the operations to
236 specify controls.
237
239 Asynchronous routines will return -1 in case of error, setting the
240 ld_errno parameter of the ld structure. Synchronous routines return
241 whatever ld_errno is set to. See ldap_error(3) for more information.
242
244 If an anonymous bind is sufficient for the application, the rebind
245 process need not be provided. The LDAP libraries with the LDAP_OPT_RE‐
246 FERRALS option set to ON (default value) will automatically follow re‐
247 ferrals using an anonymous bind.
248 If the application needs stronger authentication than an anonymous
250 bind, you need to provide a rebind process for that authentication
251 method. The bind method must be synchronous.
252
254 ldap(3), ldap_error(3), ldap_open(3), ldap_set_option(3),
255 ldap_url_parse(3) RFC 4422 (http://www.rfc-editor.org), Cyrus SASL
256 (http://asg.web.cmu.edu/sasl/)
257
259 OpenLDAP Software is developed and maintained by The OpenLDAP Project
260 <http://www.openldap.org/>. OpenLDAP Software is derived from the Uni‐
261 versity of Michigan LDAP 3.3 Release.
262OpenLDAP 2021/06/03 LDAP_BIND(3)