c# - Mono DllImport libsmbclient not authenticating -

i need able access samba/cifs share mono using specific credentials.

the best option i've found far use libsmbclient. unfortunately, can't authenticate. rule out firewall/security/etc, i've tried using smbclient executable can connect without issue.

the low-level dllimport stuff , hard-coded creds testing...

public static void initialise() {     log.trace("initialising libsmbclient wrapper");     try {         smbc_init(callbackauth, 1);     } catch (exception e) {         log.trace(string.format("{0}: {1}", e.gettype().name, e.tostring()));         throw;     } }  public static void callbackauth(     [marshalas(unmanagedtype.lpstr)]string server,     [marshalas(unmanagedtype.lpstr)]string share,     [marshalas(unmanagedtype.lpstr)]string workgroup, int workgroupmaxlen,     [marshalas(unmanagedtype.lpstr)]string username, int usernamemaxlen,     [marshalas(unmanagedtype.lpstr)]string password, int passwordmaxlen) {     server = "targetserver";     share = "public";     username = "management.service";     password = @"{somecomplexpassword}";     workgroup = "targetserver";     usernamemaxlen = username.length;     passwordmaxlen = password.length;     workgroupmaxlen = workgroup.length; }  [dllimport("libsmbclient.so", setlasterror = true)] extern internal static int smbc_init(smbcgetauthdatafn callbackauth, int debug);  [dllimport("libsmbclient.so", setlasterror = true)] extern internal static int smbc_opendir([marshalas(unmanagedtype.lpstr)]string durl); 

i'm attempting use this...

public bool directoryexists(string path) {     log.trace("checking directory exists {0}", path);     int handle;     string fullpath = @"smb:" + parseuncpath(path);     handle = sambawrapper.smbc_opendir(fullpath);     if (handle < 0) {     var error = stdlib.getlasterror().tostring();         if (error == "enoent"            |error == "einval")             return false;         else             throw new exception(error);     } else {     wrappersambaclient.smbc_close(fd);     return true; } } 

the initialise() call succeeds when directoryexists calls sambawrapper.smbc_opendir(fullpath) negative handle , throw following exception...

slurpy.exceptions.fetchexception: exception: failed fetch: eacces > (file:////targetserver/public/validsubfolder) ---> system.exception: eacces

what doing wrong? there way can debug this?

edit: seems issues values auth callback have no effect (but callback being called log statement in there processed). i'm wondering if it's immutability of strings , new string instance being created new values rather overwriting old?

edit: full debug output libsmbclient attempting connect removed. can see in edit history if required.

as requested, definition of method headers...

/**@ingroup misc  * initialize samba client library.  *  * must called before using of smbclient api function  *    * @param fn        function called obtaion   *                  authentication credentials.  *  * @param debug     allows caller set debug level. can  *                  changed in smb.conf file. allows caller set  *                  debugging if no smb.conf.  *     * @return          0 on success, < 0 on error errno set:  *                  - enomem out of memory  *                  - enoent smb.conf file not load  *  */  int smbc_init(smbc_get_auth_data_fn fn, int debug);  /**@ingroup callback  * authentication callback function type (traditional method)  *   * type the authentication function called library  * obtain authentication credentals  *  * kerberos support function should called without  * prompting user credentials. means simple 'return'  * should work. take @ examples/libsmbclient/get_auth_data_fn.h  * , examples/libsmbclient/testbrowse.c.  *  * @param srv       server being authenticated  *  * @param shr       share being authenticated  *  * @param wg        pointer buffer containing "hint"  *                  workgroup authenticated.  should filled in  *                  correct workgroup if hint wrong.  *   * @param wglen     size of workgroup buffer in bytes  *  * @param un        pointer buffer containing "hint"  *                  user name use authentication. should  *                  filled in correct workgroup if hint  *                  wrong.  *   * @param unlen     size of username buffer in bytes  *  * @param pw        pointer buffer containing password   *                  copied  *   * @param pwlen     size of password buffer in bytes  *             */ typedef void (*smbc_get_auth_data_fn)(const char *srv,                                        const char *shr,                                       char *wg, int wglen,                                        char *un, int unlen,                                       char *pw, int pwlen); 

your callback gets invoked libsmbclient, , passing buffer , length unmanaged code, expecting populate username , password. since allocated memory controlled calling side, cannot use string or stringbuilder. suggest use intptr, , populate buffer on lowest possible level.

(on other hand, server , share read-only strings, , not expected change, can keep them string).

public static void callbackauth(     [marshalas(unmanagedtype.lpstr)]string server,     [marshalas(unmanagedtype.lpstr)]string share,     intptr workgroup, int workgroupmaxlen,     intptr username, int usernamemaxlen,     intptr password, int passwordmaxlen)  {     //server = "targetserver";     //share = "public";      // should not assigned -      // must provide credentials specified server      setstring(username, "management.service", username.length);     setstring(password, @"{somecomplexpassword}", password.length);     setstring(workgroup, "targetserver", workgroup.length); }  private void setstring(intptr dest, string str, int maxlen) {     // include null string terminator     byte[] buffer = encoding.ascii.getbytes(str + "\0");     if (buffer.length >= maxlen) return; // buffer not big enough      marshal.copy(buffer, 0, dest, buffer.length); }