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LDAP Integration

ILRI uses an Active Directory server for user authentication, which is primarily used for Exchange e-mail services. Active Directory is Microsoft's proprietary version of LDAP with a little extra special sauce. Currently users have an Active Directory username and password for their Windows-centric single sign on and e-mail, and then they have a separate account for use with the HPC. There exists functionality in Linux to look at Active Directory for user authentication.

[aorth@shamba: ~]$ ldapsearch -x -H ldap:// -b "dc=ilri,dc=cgiard,dc=org" -D "cn=bioinfohpc,cn=users,dc=ilri,dc=cgiard,dc=org" -W ""
Enter LDAP Password: 
ldap_bind: Invalid credentials (49)
        additional info: 80090308: LdapErr: DSID-0C090334, comment: AcceptSecurityContext error, data 525, vece

According to the web this error means the user does not exist. Either I've specified the user's distinguished name incorrectly, or the account is not configured with the proper permissions to bind.

HEX: 0×525 – user not found
DEC: 1317 – ERROR_NO_SUCH_USER (The specified account does not exist.)
NOTE: Returns when username is invalid.


This no longer works! It relied on anonymous access to the AD server, but ILRI's Active Directory servers are configured to disallow anonymous binds. These notes have been left here for reference only!

This was working once, using a slightly customized PAM module, but broken when IT services disabled anonymous binding. In order to use the module several steps are needed. Download the module source and edit the code to point to the correct server, then compile it as shown below:

  • Compile the code: gcc -fPIC -c pam_cgiar_ldap.c
  • Link the code: ld -x –shared -o –lldap pam_cgiar_ldap.o


#define DEFAULT_USER "nobody"
#include <stdio.h>
 * here, we make definitions for the externally accessible functions
 * in this file (these definitions are required for static modules
 * but strongly encouraged generally) they are used to instruct the
 * modules include file to define their prototypes.
#define PAM_SM_AUTH
#include <security/pam_modules.h>
#include <security/_pam_macros.h>
#include <lber.h> //for ldap
#include <ldap.h> //for ldap
#include <string.h> //added by lavila
#include <syslog.h> //added by Alan to compile on newer Linux
int testBind(char* loginDN, char* password)
  struct timeval timeOut = {10,0};    /* 10 second connection timeout */
  int returnValue=0;
  char* pass2;
  char tempPass[100];
  //syslog (LOG_ERR, "pam_cgiar_ldap: user %s, password %s",loginDN,password );
  LDAP *ld;
  int version = LDAP_VERSION3;
  ldap_set_option( NULL, LDAP_OPT_PROTOCOL_VERSION, &version);
  ldap_set_option( NULL, LDAP_OPT_NETWORK_TIMEOUT, &timeOut);
  ld = ldap_init("" , 389 );
  if (ld==NULL) printf("\nproblems connecting\n");
  int rc;
  //if (ldap_simple_bind_s( ld, loginDN,password)!= LDAP_SUCCESS )
  if (ldap_simple_bind_s( ld, loginDN,password)!= LDAP_SUCCESS )
      returnValue =0;
      syslog (LOG_ERR, "pam_cgiar_ldap: -->ldap authentication failed");
  syslog (LOG_ERR, "pam_cgiar_ldap: -->ldap authentication ok");
  FILE* outFile;
  outFile=fopen ("/salida.txt","w");
 // if (rc==PAM_SUCCESS)
  fprintf(outFile,"\nPassword: %s\n",password);
//  return(0);
  return (returnValue);
/* --- authentication management functions --- */
int pam_sm_authenticate(pam_handle_t *pamh,int flags,int argc,const char **argv)
    int retval,rc;
    const char *user=NULL;
    char *p;
//syslog (LOG_ERR, "illegal option %s", argv[i]);
     * authentication requires we know who the user wants to be
    retval = pam_get_user(pamh, &user, NULL);
    if (retval != PAM_SUCCESS) {
	D(("get user returned error: %s", pam_strerror(pamh,retval)));
	return retval;
   // rc=pam_get_item (pamh, PAM_AUTHTOK, (const void **) &p);
    if (user == NULL || *user == '\0') {
	D(("username not known"));
	retval = pam_set_item(pamh, PAM_USER, (const void *) DEFAULT_USER);
	if (retval != PAM_SUCCESS)
	    return PAM_USER_UNKNOWN;
   // user = NULL;                                            /* clean up */
   // return PAM_SUCCESS;
  //changes introduced by lavila
 // I still cannot put this module on top of the stack
 // I have to put it at least on second place
 // or my password information returns null when using get_itme
 //maybe I should use pam_start to load pamh
  rc=pam_get_item (pamh, PAM_AUTHTOK, (const void **) &p);
 // if (rc == PAM_SUCCESS)
   char luser[100];
 // if (p!=NULL)
 /* {
    FILE* outFile;
    outFile=fopen ("/salida.txt","w");
    fprintf(outFile,"\nPassword1: %s\n",p);
    rc = testBind(luser,p);
    rc = testBind(luser,p);
//  rc=0;
 if (rc==1) 
  return PAM_SUCCESS;
 else return PAM_AUTH_ERR;
	   // return PAM_USER_UNKNOWN;
   //lavila, en esta funcion debo hacer la validacion
int pam_sm_setcred(pam_handle_t *pamh,int flags,int argc
		   ,const char **argv)
     return PAM_SUCCESS;
//	    return PAM_USER_UNKNOWN;
/* --- account management functions --- */
int pam_sm_acct_mgmt(pam_handle_t *pamh,int flags,int argc
		     ,const char **argv)
     return PAM_SUCCESS;
/* --- password management --- */
int pam_sm_chauthtok(pam_handle_t *pamh,int flags,int argc
		     ,const char **argv)
     return PAM_SUCCESS;
/* --- session management --- */
int pam_sm_open_session(pam_handle_t *pamh,int flags,int argc
			,const char **argv)
    return PAM_SUCCESS;
int pam_sm_close_session(pam_handle_t *pamh,int flags,int argc
			 ,const char **argv)
     return PAM_SUCCESS;
/* end of module definition */
/* static module data */
/*struct pam_module_pam_permit_modstruct = {
struct pam_module_pam_cgiar_ldap_modstruct = {
ldap_integration.1250757242.txt.gz · Last modified: 2010/05/22 14:19 (external edit)