Hi, I am working on adding NTLM single-sign-on support by using Samba's 'winbind' helper ntlm_auth.

When using Samba's 'winbind' daemon, NTLM single-sign-on is supported by delegating the NTLM challenge/response protocol to a helper in /usr/bin/ntlm_auth.
And there's a really simple test hack at http://david.woodhou.se/ntlm_auth_v2.c.

This is work-in-progress patch.
My question is how do I make it fall back to asking a password (if it needs one) when ntlm_auth failed unexpectedly?
And I am also appreciate feedbacks on finishing it. Thanks in advance.

diff --git a/configure.ac b/configure.ac
index c37ab3d..9e5e6da 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2687,6 +2687,26 @@ then
   USE_MANUAL="no";
 fi
 
+dnl **********************************************************
+dnl path of NTLM single-sign-on helper ntlm_auth
+dnl
+if test "$ac_cv_native_windows" != "yes"; then
+ AC_ARG_WITH(ntlm-auth,
+ AC_HELP_STRING([--with-ntlm-auth=PATH],[Where to look for ntlm_auth, path points to ntlm_auth installation (default: /usr/bin/ntlm_auth);])
+ AC_HELP_STRING([--without-ntlm-auth], [disable ntlm single-sign-on by using ntlm_auth]),
+ ntlm_auth="$withval",
+ ntlm_auth="/usr/bin/ntlm_auth")
+ if test "$ntlm_auth" != "no"; then
+ AC_DEFINE(USE_NTLM_AUTH, 1, [Whether or not use Samba's 'winbind' daemon helper 'ntlm_auth' for NTLM single-sign-on])
+ if test "$ntlm_auth" = "yes"; then
+ dnl --with-ntlm-auth (without path) used, use default path
+ ntlm_auth="/usr/bin/ntlm_auth"
+ fi
+ fi
+ AC_SUBST(ntlm_auth)
+ AC_DEFINE_UNQUOTED(NTLM_AUTH, "$ntlm_auth", [Samba's 'winbind' daemon helper 'ntlm_auth' which can be used for NTLM single-sign-on])
+fi
+
 dnl *************************************************************************
 dnl If the manual variable still is set, then we go with providing a built-in
 dnl manual
diff --git a/lib/http.c b/lib/http.c
index 3d9f2f2..1f7a970 100644
--- a/lib/http.c
+++ b/lib/http.c
@@ -450,14 +450,22 @@ CURLcode Curl_http_auth_act(struct connectdata *conn)
   if(data->state.authproblem)
     return data->set.http_fail_on_error?CURLE_HTTP_RETURNED_ERROR:CURLE_OK;
 
+#ifdef USE_NTLM_SSO
+ if(1 &&
+#else
   if(conn->bits.user_passwd &&
+#endif
      ((data->req.httpcode == 401) ||
       (conn->bits.authneg && data->req.httpcode < 300))) {
     pickhost = pickoneauth(&data->state.authhost);
     if(!pickhost)
       data->state.authproblem = TRUE;
   }
+#ifdef USE_NTLM_SSO
+ if(1 &&
+#else
   if(conn->bits.proxy_user_passwd &&
+#endif
      ((data->req.httpcode == 407) ||
       (conn->bits.authneg && data->req.httpcode < 300))) {
     pickproxy = pickoneauth(&data->state.authproxy);
@@ -630,9 +638,13 @@ Curl_http_output_auth(struct connectdata *conn,
      conn->bits.user_passwd)
     /* continue please */ ;
   else {
+#ifdef USE_NTLM_SSO
+ /* NTLM single-sign-on, continue please */ ;
+#else
     authhost->done = TRUE;
     authproxy->done = TRUE;
     return CURLE_OK; /* no authentication with no user or password */
+#endif
   }
 
   if(authhost->want && !authhost->picked)
@@ -3349,7 +3361,6 @@ CURLcode Curl_http_readwrite_headers(struct SessionHandle *data,
   /* We might have reached the end of the header part here, but
      there might be a non-header part left in the end of the read
      buffer. */
-
   return CURLE_OK;
 }
 
diff --git a/lib/http_ntlm.c b/lib/http_ntlm.c
index c3ceadc..88c50ef 100644
--- a/lib/http_ntlm.c
+++ b/lib/http_ntlm.c
@@ -43,6 +43,15 @@
 #include <unistd.h>
 #endif
 
+#ifdef USE_NTLM_SSO
+#include <unistd.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <signal.h>
+#include <errno.h>
+#endif
+
 #if (defined(NETWARE) && !defined(__NOVELL_LIBC__))
 #include <netdb.h>
 #endif
@@ -321,6 +330,11 @@ CURLntlm Curl_input_ntlm(struct connectdata *conn,
       ntlm->flags = readint_le(&buffer[20]);
       memcpy(ntlm->nonce, &buffer[24], 8);
 
+#ifdef USE_NTLM_SSO
+ if(conn->sso_data)
+ conn->sso_data->challenge_header = strdup(header);
+#endif
+
       DEBUG_OUT({
         fprintf(stderr, "**** TYPE2 header flags=0x%08.8lx ", ntlm->flags);
         print_flags(stderr, ntlm->flags);
@@ -674,6 +688,133 @@ static void unicodecpy(unsigned char *dest,
 }
 #endif
 
+#ifdef USE_NTLM_SSO
+static void sso_ntlm_close(struct ntlmhelper *sso_data)
+{
+ if(sso_data->fd_helper != -1) {
+ close (sso_data->fd_helper);
+ sso_data->fd_helper = -1;
+ }
+
+ if(sso_data->pid) {
+ int ret, i;
+ for(i = 0; i < 4; i++) {
+ ret = waitpid (sso_data->pid, NULL, WNOHANG);
+ if(ret == sso_data->pid || errno == ECHILD)
+ break;
+ switch (i) {
+ case 0:
+ kill (sso_data->pid, SIGTERM);
+ break;
+ case 2:
+ kill (sso_data->pid, SIGKILL);
+ break;
+ case 1:
+ case 3:
+ sleep (1);
+ break;
+ }
+ }
+ sso_data->pid = 0;
+ }
+
+ if(sso_data->challenge_header)
+ free(sso_data->challenge_header);
+}
+
+static bool sso_ntlm_initiate(struct ntlmhelper *sso_data)
+{
+ int sockfds[2];
+ pid_t pid;
+ char *username = NULL, *slash, *domain = NULL;
+
+ if(sso_data->fd_helper != -1 || sso_data->pid) {
+ return TRUE;
+ }
+
+ username = getenv("NTLMUSER");
+ if(!username)
+ username = getenv("USER");
+ if(!username)
+ goto done;
+
+ slash = strpbrk(username, "\\/");
+ if(slash) {
+ domain = strdup(username);
+ slash = domain + (slash - username);
+ *slash = '\0';
+ username = slash + 1;
+ }
+
+ if(access(NTLM_AUTH, X_OK) != 0)
+ goto done;
+
+ if(socketpair(AF_UNIX, SOCK_STREAM, 0, sockfds))
+ goto done;
+
+ pid = fork();
+ if(!pid) {
+ /* child process */
+ if(dup2 (sockfds[1], 0) == -1 || dup2 (sockfds[1], 1) == -1)
+ exit(1);
+
+ execl(NTLM_AUTH, "--helper-protocol", "ntlmssp-client-1",
+ "--use-cached-creds", "--username", username,
+ domain?"--domain":NULL, domain, NULL);
+ exit(1);
+ }else if(pid == -1) {
+ close (sockfds[0]);
+ close (sockfds[1]);
+ goto done;
+ }
+
+ close (sockfds[1]);
+ sso_data->fd_helper = sockfds[0];
+ sso_data->pid = pid;
+ if(domain)
+ free (domain);
+ return TRUE;
+
+ done:
+ if(domain)
+ free (domain);
+ return FALSE;
+}
+
+static char *sso_ntlm_response (struct ntlmhelper *sso_data,
+ const char *input, curlntlm state)
+{
+ ssize_t size;
+ char buf[1024], *response = NULL;
+
+ if(write (sso_data->fd_helper, input, strlen (input)) < 0 ||
+ (size = read (sso_data->fd_helper, buf, 1024)) < 5 ) {
+ goto done;
+ }
+ /* Samba/winbind installed but not configured */
+ if(state == NTLMSTATE_TYPE1 &&
+ buf[0] == 'P' && buf[1] == 'W' && buf[size-1] == '\n') {
+ response = strdup ("PW");
+ goto done;
+ }
+ /* invalid response */
+ if(state == NTLMSTATE_TYPE1 &&
+ (buf[0] != 'Y' || buf[1] != 'R' || buf[2] != ' ' || buf[size-1] != '\n'))
+ goto done;
+ if(state == NTLMSTATE_TYPE2 &&
+ (buf[0]!='K' || buf[1]!='K' || buf[2]!=' ' || buf[size-1]!='\n') &&
+ (buf[0]!='A' || buf[1]!='F' || buf[2]!=' ' || buf[size-1]!='\n'))
+ goto done;
+
+ response = strndup(buf + 3, size - 4);
+ *(response + size - 4) = '\0';
+ response = aprintf("NTLM %s", response);
+ goto done;
+done:
+ return response;
+}
+#endif /* USE_NTLM_AUTH */
+
 /* this is for creating ntlm header output */
 CURLcode Curl_output_ntlm(struct connectdata *conn,
                           bool proxy)
@@ -832,6 +973,50 @@ CURLcode Curl_output_ntlm(struct connectdata *conn,
     size = buf.cbBuffer;
   }
 #else
+
+#ifdef USE_NTLM_SSO
+ /* Use Samba's 'winbind' daemon to support NTLM single-sign-on,
+ * by delegating the NTLM challenge/response protocal to a helper
+ * in ntlm_auth.
+ * http://devel.squid-cache.org/ntlm/squid_helper_protocol.html
+ * http://www.samba.org/samba/docs/man/manpages-3/winbindd.8.html
+ * http://www.samba.org/samba/docs/man/manpages-3/ntlm_auth.1.html
+ * The preprocessor variable 'USE_NTLM_AUTH' indicates whether
+ * this feature is enabled. Another one 'NTLM_AUTH' contains absolute
+ * path of it.
+ * If NTLM single-sign-on fails, go back to original request
+ * handling process.
+ */
+ /* Fix me later */
+ conn->sso_data = calloc(1, sizeof(struct ntlmhelper));
+ conn->sso_data->fd_helper = -1;
+ conn->sso_data->pid = 0;
+ conn->sso_data->challenge_header = NULL;
+
+ if(sso_ntlm_initiate(conn->sso_data)) {
+ char *header;
+ header = sso_ntlm_response(conn->sso_data, "YR\n", ntlm->state);
+ if(!header)
+ /* invalid response */
+ goto ssofailure_type1;
+ if(!strcasecmp(header, "PW")) {
+ /* ntml_auth ask for password */
+ free(header);
+ header = NULL;
+ goto ssofailure_type1;
+ }
+ Curl_safefree(*allocuserpwd);
+ *allocuserpwd = aprintf("%sAuthorization: %s\r\n",
+ proxy?"Proxy-":"",
+ header);
+ DEBUG_OUT(fprintf(stderr, "**** Header %s\n ", *allocuserpwd));
+ free(header);
+ break;
+ }
+ssofailure_type1:
+ DEBUG_OUT(fprintf(stderr, "**** ntlm_auth failed on type1\n"));
+#endif
+
     hostoff = 0;
     domoff = hostoff + hostlen; /* This is 0: remember that host and domain
                                    are empty */
@@ -998,6 +1183,31 @@ CURLcode Curl_output_ntlm(struct connectdata *conn,
     size_t userlen;
     CURLcode res;
 
+#ifdef USE_NTLM_SSO
+ char *input, *header;
+ input = aprintf ("TT %s\n", conn->sso_data->challenge_header);
+ header = sso_ntlm_response(conn->sso_data,
+ input,
+ ntlm->state);
+ sso_ntlm_close(conn->sso_data);
+ if(!header) {
+ free(input);
+ goto ssofailure_type2;
+ }
+ Curl_safefree(*allocuserpwd);
+ *allocuserpwd = aprintf("%sAuthorization: %s\r\n",
+ proxy?"Proxy-":"",
+ header);
+ DEBUG_OUT(fprintf(stderr, "**** %s\n ", *allocuserpwd));
+ ntlm->state = NTLMSTATE_TYPE3; /* we sent a type-3 */
+ authp->done = TRUE;
+ free(input);
+ free(header);
+ break;
+ssofailure_type2:
+ DEBUG_OUT(fprintf(stderr, "**** ntlm_auth failed on type2\n"));
+#endif
+
     user = strchr(userp, '\\');
     if(!user)
       user = strchr(userp, '/');
diff --git a/lib/setup.h b/lib/setup.h
index 1e96c76..c742188 100644
--- a/lib/setup.h
+++ b/lib/setup.h
@@ -567,6 +567,11 @@ int netware_init(void);
 #if defined(USE_SSLEAY) || defined(USE_WINDOWS_SSPI) || \
    defined(USE_GNUTLS) || defined(USE_NSS)
 #define USE_NTLM
+#if defined(USE_NTLM_AUTH)
+/* Support NTLM single-sign-on by using Samba's winbind daemon helper
+ 'ntlm_auth' */
+#define USE_NTLM_SSO
+#endif
 #endif
 #endif
 
diff --git a/lib/urldata.h b/lib/urldata.h
index d256968..5a08816 100644
--- a/lib/urldata.h
+++ b/lib/urldata.h
@@ -69,6 +69,10 @@
 #include "cookie.h"
 #include "formdata.h"
 
+#ifdef USE_NTLM_SSO
+#include <sys/types.h>
+#endif
+
 #ifdef USE_SSLEAY
 #ifdef USE_OPENSSL
 #include <openssl/rsa.h>
@@ -367,6 +371,16 @@ struct ntlmdata {
 #endif
 };
 
+/* Struct used for NTLM single-sign-on with Samba's winbind daemon helper
+ ntlm_auth */
+#ifdef USE_NTLM_SSO
+struct ntlmhelper {
+ int fd_helper;
+ pid_t pid;
+ char* challenge_header;
+};
+#endif
+
 #ifdef USE_HTTP_NEGOTIATE
 struct negotiatedata {
   /* when doing Negotiate we first need to receive an auth token and then we
@@ -905,6 +919,12 @@ struct connectdata {
                                single requests! */
   struct ntlmdata proxyntlm; /* NTLM data for proxy */
 
+#ifdef USE_NTLM_SSO
+ /* data used for communication with Samba's winbind daemon helper
+ ntlm_auth */
+ struct ntlmhelper *sso_data;
+#endif
+
   char syserr_buf [256]; /* buffer for Curl_strerror() */
 
 #ifdef CURLRES_ASYNCH

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Received on 2011-06-20