Developing the SASL Client

To test the plug-in, you need a client that uses my_sasl_mechanism to bind. The example discussed here uses this mechanism and the client code, saslclient.c, which is delivered with Directory Server.

The client authenticates by using the example SASL mechanism for a synchronous bind to Directory Server. The following example shows how authentication proceeds on the client side for Ted Morris.

Example 7–4 Client Using my_sasl_mechanism (clients/saslclient.c)

#include "ldap.h"

/* Use the fake SASL mechanism.                                      */
#define MECH "my_sasl_mechanism"

/* Global variables for client connection information.
 * You may set these here or on the command line.                    */
static char * host = "localhost";      /* Server hostname            */
static int    port = 389;              /* Server port                */
/* Load <install-path>/ldif/Example.ldif
 * before trying the plug-in with this default user.                 */
static char * user = "uid=tmorris,ou=people,dc=example,dc=com";
/* New value for userPassword                                        */
static char * npwd = "23skidoo";

/* Check for host, port, user and new password as arguments.         */
int get_user_args(int argc, char ** argv);

int
main(int argc, char ** argv)
{
    LDAP          * ld;                /* Handle to LDAP connection  */
    LDAPMod         modPW, * mods[2];  /* For modifying the password */
    char          * vals[2];           /* Value of modified password */
    struct berval   cred;              /* Client bind credentials    */
    struct berval * srvCred;           /* Server bind credentials    */
    int             ldapVersion;

    /* Use default hostname, server port, user, and new password
     * unless they are provided as arguments on the command line.    */
    if (get_user_args(argc, argv) != 0) return 1; /* Usage error     */
    
    /* Get a handle to an LDAP connection.                           */
    printf("Getting the handle to the LDAP connection...\n");
    if ((ld = ldap_init(host, port)) == NULL) {
        perror("ldap_init");
        return 1;
    }

    /* By default, the LDAP version is set to 2.                     */
    printf("Setting the version to LDAP v3...\n");
    ldapVersion = LDAP_VERSION3;
    ldap_set_option(ld, LDAP_OPT_PROTOCOL_VERSION, &ldapVersion);

    /* Authenticate using the example SASL mechanism.                */
    printf("Bind DN is %s...\n", user);
    printf("Binding to the server using %s...\n", MECH);
    cred.bv_val = "magic";
    cred.bv_len = sizeof("magic") - 1;
    if (ldap_sasl_bind_s(ld, user, MECH, &cred, NULL, NULL, &srvCred)) {
        ldap_perror(ld, "ldap_sasl_bind_s");
        return 1;
    }

    /* Display the credentials returned by the server.               */
    printf("Server credentials: %s\n", srvCred->bv_val);

    /* Modify the user's password.                                   */
    printf("Modifying the password...\n");
    modPW.mod_op     = LDAP_MOD_REPLACE;
    modPW.mod_type   = "userpassword";
    vals[0]          = npwd;
    vals[1]          = NULL;
    modPW.mod_values = vals;

    mods[0] = &modPW; mods[1] = NULL;

    if (ldap_modify_ext_s(ld, user, mods, NULL, NULL)) {
        ldap_perror(ld, "ldap_modify_ext_s");
        return 1;
    }

    /* Finish up.                                                    */
    ldap_unbind(ld);
    printf("Modification was successful.\n");
    return 0;
}