Move our basic password checking code from inside the authentication

subsystem into a seperate file - ntlm_check.c.

This allows us to call these routines from ntlm_auth.  The purpose of this
exercise is to allow ntlm_auth (when operating as an NTLMSSP server) to
avoid talking to winbind.  This should allow for easier debugging.

ntlm_auth itself has been reorgainised, so as to share more code between
the SPNEGO-wrapped and 'raw' NTLMSSP modes.  A new 'client' NTLMSSP mode
has been added, for use with a Cyrus-SASL module I am writing (based on vl's
work)

Andrew Bartlett
(This used to be commit 48315e8fd227978e0161be293ad4411b45e3ea5b)

4 files changed, 634 insertions, 400 deletions

diff --git a/source3/Makefile.in b/source3/Makefile.in
index e1087b9eb5..3fa53c577d 100644
--- a/source3/Makefile.in
+++ b/source3/Makefile.in
@@ -213,7 +213,8 @@ SECRETS_OBJ = passdb/secrets.o
 LIBNMB_OBJ = libsmb/unexpected.o libsmb/namecache.o libsmb/nmblib.o \
 	     libsmb/namequery.o libsmb/conncache.o 
 
-LIBSAMBA_OBJ = libsmb/nterr.o libsmb/smbdes.o libsmb/smbencrypt.o libsmb/ntlmssp.o libsmb/ntlmssp_parse.o libsmb/ntlmssp_sign.o
+LIBSAMBA_OBJ = libsmb/nterr.o libsmb/smbdes.o libsmb/smbencrypt.o libsmb/ntlm_check.o \
+	libsmb/ntlmssp.o libsmb/ntlmssp_parse.o libsmb/ntlmssp_sign.o
 
 LIBSMB_OBJ = libsmb/clientgen.o libsmb/cliconnect.o libsmb/clifile.o \
 	     libsmb/clikrb5.o libsmb/clispnego.o libsmb/asn1.o \
diff --git a/source3/auth/auth_sam.c b/source3/auth/auth_sam.c
index 04b587343a..ebb1e3d861 100644
--- a/source3/auth/auth_sam.c
+++ b/source3/auth/auth_sam.c
@@ -3,7 +3,7 @@
    Password and authentication handling
    Copyright (C) Andrew Tridgell              1992-2000
    Copyright (C) Luke Kenneth Casson Leighton 1996-2000
-   Copyright (C) Andrew Bartlett              2001
+   Copyright (C) Andrew Bartlett              2001-2003
    Copyright (C) Gerald Carter                2003
    
    This program is free software; you can redistribute it and/or modify
@@ -27,350 +27,6 @@
 #define DBGC_CLASS DBGC_AUTH
 
 /****************************************************************************
- Core of smb password checking routine.
-****************************************************************************/
-
-static BOOL smb_pwd_check_ntlmv1(const DATA_BLOB *nt_response,
-				 const uchar *part_passwd,
-				 const DATA_BLOB *sec_blob,
-				 DATA_BLOB *user_sess_key)
-{
-	/* Finish the encryption of part_passwd. */
-	uchar p24[24];
-	
-	if (part_passwd == NULL) {
-		DEBUG(10,("No password set - DISALLOWING access\n"));
-		/* No password set - always false ! */
-		return False;
-	}
-	
-	if (sec_blob->length != 8) {
-		DEBUG(0, ("smb_pwd_check_ntlmv1: incorrect challenge size (%lu)\n", (unsigned long)sec_blob->length));
-		return False;
-	}
-	
-	if (nt_response->length != 24) {
-		DEBUG(0, ("smb_pwd_check_ntlmv1: incorrect password length (%lu)\n", (unsigned long)nt_response->length));
-		return False;
-	}
-
-	SMBOWFencrypt(part_passwd, sec_blob->data, p24);
-	if (user_sess_key != NULL) {
-		*user_sess_key = data_blob(NULL, 16);
-		SMBsesskeygen_ntv1(part_passwd, NULL, user_sess_key->data);
-	}
-	
-	
-	
-#if DEBUG_PASSWORD
-	DEBUG(100,("Part password (P16) was |\n"));
-	dump_data(100, part_passwd, 16);
-	DEBUGADD(100,("Password from client was |\n"));
-	dump_data(100, nt_response->data, nt_response->length);
-	DEBUGADD(100,("Given challenge was |\n"));
-	dump_data(100, sec_blob->data, sec_blob->length);
-	DEBUGADD(100,("Value from encryption was |\n"));
-	dump_data(100, p24, 24);
-#endif
-  return (memcmp(p24, nt_response->data, 24) == 0);
-}
-
-/****************************************************************************
- Core of smb password checking routine. (NTLMv2, LMv2)
- Note:  The same code works with both NTLMv2 and LMv2.
-****************************************************************************/
-
-static BOOL smb_pwd_check_ntlmv2(const DATA_BLOB *ntv2_response,
-				 const uchar *part_passwd,
-				 const DATA_BLOB *sec_blob,
-				 const char *user, const char *domain,
-				 DATA_BLOB *user_sess_key)
-{
-	/* Finish the encryption of part_passwd. */
-	uchar kr[16];
-	uchar value_from_encryption[16];
-	uchar client_response[16];
-	DATA_BLOB client_key_data;
-
-	if (part_passwd == NULL) {
-		DEBUG(10,("No password set - DISALLOWING access\n"));
-		/* No password set - always False */
-		return False;
-	}
-
-	if (ntv2_response->length < 24) {
-		/* We MUST have more than 16 bytes, or the stuff below will go
-		   crazy.  No known implementation sends less than the 24 bytes
-		   for LMv2, let alone NTLMv2. */
-		DEBUG(0, ("smb_pwd_check_ntlmv2: incorrect password length (%lu)\n", 
-			  (unsigned long)ntv2_response->length));
-		return False;
-	}
-
-	client_key_data = data_blob(ntv2_response->data+16, ntv2_response->length-16);
-	/* 
-	   todo:  should we be checking this for anything?  We can't for LMv2, 
-	   but for NTLMv2 it is meant to contain the current time etc.
-	*/
-
-	memcpy(client_response, ntv2_response->data, sizeof(client_response));
-
-	if (!ntv2_owf_gen(part_passwd, user, domain, kr)) {
-		return False;
-	}
-
-	SMBOWFencrypt_ntv2(kr, sec_blob, &client_key_data, value_from_encryption);
-	if (user_sess_key != NULL) {
-		*user_sess_key = data_blob(NULL, 16);
-		SMBsesskeygen_ntv2(kr, value_from_encryption, user_sess_key->data);
-	}
-
-#if DEBUG_PASSWORD
-	DEBUG(100,("Part password (P16) was |\n"));
-	dump_data(100, part_passwd, 16);
-	DEBUGADD(100,("Password from client was |\n"));
-	dump_data(100, ntv2_response->data, ntv2_response->length);
-	DEBUGADD(100,("Variable data from client was |\n"));
-	dump_data(100, client_key_data.data, client_key_data.length);
-	DEBUGADD(100,("Given challenge was |\n"));
-	dump_data(100, sec_blob->data, sec_blob->length);
-	DEBUGADD(100,("Value from encryption was |\n"));
-	dump_data(100, value_from_encryption, 16);
-#endif
-	data_blob_clear_free(&client_key_data);
-	return (memcmp(value_from_encryption, client_response, 16) == 0);
-}
-
-/**
- * Check a challenge-response password against the value of the NT or
- * LM password hash.
- *
- * @param mem_ctx talloc context
- * @param challenge 8-byte challenge.  If all zero, forces plaintext comparison
- * @param nt_response 'unicode' NT response to the challenge, or unicode password
- * @param lm_response ASCII or LANMAN response to the challenge, or password in DOS code page
- * @param username internal Samba username, for log messages
- * @param client_username username the client used
- * @param client_domain domain name the client used (may be mapped)
- * @param nt_pw MD4 unicode password from our passdb or similar
- * @param lm_pw LANMAN ASCII password from our passdb or similar
- * @param user_sess_key User session key
- * @param lm_sess_key LM session key (first 8 bytes of the LM hash)
- */
-
-static NTSTATUS ntlm_password_check(TALLOC_CTX *mem_ctx,
-				    const DATA_BLOB *challenge,
-				    const DATA_BLOB *lm_response,
-				    const DATA_BLOB *nt_response,
-				    const char *username, 
-				    const char *client_username, 
-				    const char *client_domain,
-				    const uint8 *lm_pw, const uint8 *nt_pw, 
-				    DATA_BLOB *user_sess_key, 
-				    DATA_BLOB *lm_sess_key)
-{
-	static const unsigned char zeros[8];
-	if (nt_pw == NULL) {
-		DEBUG(3,("sam_password_ok: NO NT password stored for user %s.\n", 
-			 username));
-	}
-
-	/* Check for cleartext netlogon. Used by Exchange 5.5. */
-	if (challenge->length == sizeof(zeros) && 
-	    (memcmp(challenge->data, zeros, challenge->length) == 0 )) {
-
-		DEBUG(4,("sam_password_ok: checking plaintext passwords for user %s\n",
-			 username));
-		if (nt_pw && nt_response->length) {
-			unsigned char pwhash[16];
-			mdfour(pwhash, nt_response->data, nt_response->length);
-			if (memcmp(pwhash, nt_pw, sizeof(pwhash)) == 0) {
-				return NT_STATUS_OK;
-			} else {
-				DEBUG(3,("sam_password_ok: NT (Unicode) plaintext password check failed for user %s\n",
-					 username));
-				return NT_STATUS_WRONG_PASSWORD;
-			}
-
-		} else if (!lp_lanman_auth()) {
-			DEBUG(3,("sam_password_ok: (plaintext password check) LANMAN passwords NOT PERMITTED for user %s\n",
-				 username));
-
-		} else if (lm_pw && lm_response->length) {
-			uchar dospwd[14]; 
-			uchar p16[16]; 
-			ZERO_STRUCT(dospwd);
-			
-			DEBUG(100, ("DOS password: %s\n"));
-			memcpy(dospwd, lm_response->data, MIN(lm_response->length, sizeof(dospwd)));
-			/* Only the fisrt 14 chars are considered, password need not be null terminated. */
-			E_P16((const unsigned char *)dospwd, p16);
-
-			dump_data_pw("DOS password (first buffer)\n", dospwd, 14);
-			dump_data_pw("DOS password (wire DES hash)\n", p16, 16);
-			dump_data_pw("DOS password (passdb DES hash)\n", lm_pw, 16);
-			if (memcmp(p16, lm_pw, sizeof(p16)) == 0) {
-				return NT_STATUS_OK;
-			} else {
-				DEBUG(3,("sam_password_ok: LANMAN (ASCII) plaintext password check failed for user %s\n",
-					 username));
-				return NT_STATUS_WRONG_PASSWORD;
-			}
-		} else {
-			DEBUG(3, ("Plaintext authentication for user %s attempted, but neither NT nor LM passwords available\n", username));
-			return NT_STATUS_WRONG_PASSWORD;
-		}
-	}
-
-	if (nt_response->length != 0 && nt_response->length < 24) {
-		DEBUG(2,("sam_password_ok: invalid NT password length (%lu) for user %s\n", 
-			 (unsigned long)nt_response->length, username));		
-	}
-	
-	if (nt_response->length >= 24 && nt_pw) {
-		if (nt_response->length > 24) {
-			/* We have the NT MD4 hash challenge available - see if we can
-			   use it (ie. does it exist in the smbpasswd file).
-			*/
-			DEBUG(4,("sam_password_ok: Checking NTLMv2 password with domain [%s]\n", client_domain));
-			if (smb_pwd_check_ntlmv2( nt_response, 
-						  nt_pw, challenge, 
-					  client_username, 
-						  client_domain,
-						  user_sess_key)) {
-				return NT_STATUS_OK;
-			}
-			
-			DEBUG(4,("sam_password_ok: Checking NTLMv2 password without a domain\n"));
-			if (smb_pwd_check_ntlmv2( nt_response, 
-						  nt_pw, challenge, 
-						  client_username, 
-						  "",
-						  user_sess_key)) {
-				return NT_STATUS_OK;
-			} else {
-				DEBUG(3,("sam_password_ok: NTLMv2 password check failed\n"));
-				return NT_STATUS_WRONG_PASSWORD;
-			}
-		}
-
-		if (lp_ntlm_auth()) {		
-			/* We have the NT MD4 hash challenge available - see if we can
-			   use it (ie. does it exist in the smbpasswd file).
-			*/
-			DEBUG(4,("sam_password_ok: Checking NT MD4 password\n"));
-			if (smb_pwd_check_ntlmv1(nt_response, 
-						 nt_pw, challenge,
-						 user_sess_key)) {
-				/* The LM session key for this response is not very secure, 
-				   so use it only if we otherwise allow LM authentication */
-
-				if (lp_lanman_auth() && lm_pw) {
-					uint8 first_8_lm_hash[16];
-					memcpy(first_8_lm_hash, lm_pw, 8);
-					memset(first_8_lm_hash + 8, '\0', 8);
-					*lm_sess_key = data_blob(first_8_lm_hash, 16);
-				}
-				return NT_STATUS_OK;
-			} else {
-				DEBUG(3,("sam_password_ok: NT MD4 password check failed for user %s\n",
-					 username));
-				return NT_STATUS_WRONG_PASSWORD;
-			}
-		} else {
-			DEBUG(2,("sam_password_ok: NTLMv1 passwords NOT PERMITTED for user %s\n",
-				 username));			
-			/* no return, becouse we might pick up LMv2 in the LM field */
-		}
-	}
-	
-	if (lm_response->length == 0) {
-		DEBUG(3,("sam_password_ok: NEITHER LanMan nor NT password supplied for user %s\n",
-			 username));
-		return NT_STATUS_WRONG_PASSWORD;
-	}
-	
-	if (lm_response->length < 24) {
-		DEBUG(2,("sam_password_ok: invalid LanMan password length (%lu) for user %s\n", 
-			 (unsigned long)nt_response->length, username));		
-		return NT_STATUS_WRONG_PASSWORD;
-	}
-		
-	if (!lp_lanman_auth()) {
-		DEBUG(3,("sam_password_ok: Lanman passwords NOT PERMITTED for user %s\n",
-			 username));
-	} else if (!lm_pw) {
-		DEBUG(3,("sam_password_ok: NO LanMan password set for user %s (and no NT password supplied)\n",
-			 username));
-	} else {
-		DEBUG(4,("sam_password_ok: Checking LM password\n"));
-		if (smb_pwd_check_ntlmv1(lm_response, 
-					 lm_pw, challenge,
-					 NULL)) {
-			uint8 first_8_lm_hash[16];
-			memcpy(first_8_lm_hash, lm_pw, 8);
-			memset(first_8_lm_hash + 8, '\0', 8);
-			*user_sess_key = data_blob(first_8_lm_hash, 16);
-			*lm_sess_key = data_blob(first_8_lm_hash, 16);
-			return NT_STATUS_OK;
-		}
-	}
-	
-	if (!nt_pw) {
-		DEBUG(4,("sam_password_ok: LM password check failed for user, no NT password %s\n",username));
-		return NT_STATUS_WRONG_PASSWORD;
-	}
-	
-	/* This is for 'LMv2' authentication.  almost NTLMv2 but limited to 24 bytes.
-	   - related to Win9X, legacy NAS pass-though authentication
-	*/
-	DEBUG(4,("sam_password_ok: Checking LMv2 password with domain %s\n", client_domain));
-	if (smb_pwd_check_ntlmv2( lm_response, 
-				  nt_pw, challenge, 
-				  client_username,
-				  client_domain,
-				  NULL)) {
-		return NT_STATUS_OK;
-	}
-	
-	DEBUG(4,("sam_password_ok: Checking LMv2 password without a domain\n"));
-	if (smb_pwd_check_ntlmv2( lm_response, 
-				  nt_pw, challenge, 
-				  client_username,
-				  "",
-				  NULL)) {
-		return NT_STATUS_OK;
-	}
-
-	/* Apparently NT accepts NT responses in the LM field
-	   - I think this is related to Win9X pass-though authentication
-	*/
-	DEBUG(4,("sam_password_ok: Checking NT MD4 password in LM field\n"));
-	if (lp_ntlm_auth()) {
-		if (smb_pwd_check_ntlmv1(lm_response, 
-					 nt_pw, challenge,
-					 NULL)) {
-			/* The session key for this response is still very odd.  
-			   It not very secure, so use it only if we otherwise 
-			   allow LM authentication */
-
-			if (lp_lanman_auth() && lm_pw) {
-				uint8 first_8_lm_hash[16];
-				memcpy(first_8_lm_hash, lm_pw, 8);
-				memset(first_8_lm_hash + 8, '\0', 8);
-				*user_sess_key = data_blob(first_8_lm_hash, 16);
-				*lm_sess_key = data_blob(first_8_lm_hash, 16);
-			}
-			return NT_STATUS_OK;
-		}
-		DEBUG(3,("sam_password_ok: LM password, NT MD4 password in LM field and LMv2 failed for user %s\n",username));
-	} else {
-		DEBUG(3,("sam_password_ok: LM password and LMv2 failed for user %s, and NT MD4 password in LM field not permitted\n",username));
-	}
-	return NT_STATUS_WRONG_PASSWORD;
-}
-
-/****************************************************************************
  Do a specific test for an smb password being correct, given a smb_password and
  the lanman and NT responses.
 ****************************************************************************/
diff --git a/source3/libsmb/ntlm_check.c b/source3/libsmb/ntlm_check.c
new file mode 100644
index 0000000000..362b640f91
--- /dev/null
+++ b/source3/libsmb/ntlm_check.c
@@ -0,0 +1,377 @@
+/* 
+   Unix SMB/CIFS implementation.
+   Password and authentication handling
+   Copyright (C) Andrew Tridgell              1992-2000
+   Copyright (C) Luke Kenneth Casson Leighton 1996-2000
+   Copyright (C) Andrew Bartlett              2001-2003
+   Copyright (C) Gerald Carter                2003
+   
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+   
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+   
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+#include "includes.h"
+
+#undef DBGC_CLASS
+#define DBGC_CLASS DBGC_AUTH
+
+/****************************************************************************
+ Core of smb password checking routine.
+****************************************************************************/
+
+static BOOL smb_pwd_check_ntlmv1(const DATA_BLOB *nt_response,
+				 const uchar *part_passwd,
+				 const DATA_BLOB *sec_blob,
+				 DATA_BLOB *user_sess_key)
+{
+	/* Finish the encryption of part_passwd. */
+	uchar p24[24];
+	
+	if (part_passwd == NULL) {
+		DEBUG(10,("No password set - DISALLOWING access\n"));
+		/* No password set - always false ! */
+		return False;
+	}
+	
+	if (sec_blob->length != 8) {
+		DEBUG(0, ("smb_pwd_check_ntlmv1: incorrect challenge size (%lu)\n", 
+			  (unsigned long)sec_blob->length));
+		return False;
+	}
+	
+	if (nt_response->length != 24) {
+		DEBUG(0, ("smb_pwd_check_ntlmv1: incorrect password length (%lu)\n", 
+			  (unsigned long)nt_response->length));
+		return False;
+	}
+
+	SMBOWFencrypt(part_passwd, sec_blob->data, p24);
+	if (user_sess_key != NULL) {
+		*user_sess_key = data_blob(NULL, 16);
+		SMBsesskeygen_ntv1(part_passwd, NULL, user_sess_key->data);
+	}
+	
+	
+#if DEBUG_PASSWORD
+	DEBUG(100,("Part password (P16) was |\n"));
+	dump_data(100, part_passwd, 16);
+	DEBUGADD(100,("Password from client was |\n"));
+	dump_data(100, nt_response->data, nt_response->length);
+	DEBUGADD(100,("Given challenge was |\n"));
+	dump_data(100, sec_blob->data, sec_blob->length);
+	DEBUGADD(100,("Value from encryption was |\n"));
+	dump_data(100, p24, 24);
+#endif
+	return (memcmp(p24, nt_response->data, 24) == 0);
+}
+
+/****************************************************************************
+ Core of smb password checking routine. (NTLMv2, LMv2)
+ Note:  The same code works with both NTLMv2 and LMv2.
+****************************************************************************/
+
+static BOOL smb_pwd_check_ntlmv2(const DATA_BLOB *ntv2_response,
+				 const uchar *part_passwd,
+				 const DATA_BLOB *sec_blob,
+				 const char *user, const char *domain,
+				 DATA_BLOB *user_sess_key)
+{
+	/* Finish the encryption of part_passwd. */
+	uchar kr[16];
+	uchar value_from_encryption[16];
+	uchar client_response[16];
+	DATA_BLOB client_key_data;
+
+	if (part_passwd == NULL) {
+		DEBUG(10,("No password set - DISALLOWING access\n"));
+		/* No password set - always False */
+		return False;
+	}
+
+	if (sec_blob->length != 8) {
+		DEBUG(0, ("smb_pwd_check_ntlmv2: incorrect challenge size (%lu)\n", 
+			  (unsigned long)sec_blob->length));
+		return False;
+	}
+	
+	if (ntv2_response->length < 24) {
+		/* We MUST have more than 16 bytes, or the stuff below will go
+		   crazy.  No known implementation sends less than the 24 bytes
+		   for LMv2, let alone NTLMv2. */
+		DEBUG(0, ("smb_pwd_check_ntlmv2: incorrect password length (%lu)\n", 
+			  (unsigned long)ntv2_response->length));
+		return False;
+	}
+
+	client_key_data = data_blob(ntv2_response->data+16, ntv2_response->length-16);
+	/* 
+	   todo:  should we be checking this for anything?  We can't for LMv2, 
+	   but for NTLMv2 it is meant to contain the current time etc.
+	*/
+
+	memcpy(client_response, ntv2_response->data, sizeof(client_response));
+
+	if (!ntv2_owf_gen(part_passwd, user, domain, kr)) {
+		return False;
+	}
+
+	SMBOWFencrypt_ntv2(kr, sec_blob, &client_key_data, value_from_encryption);
+	if (user_sess_key != NULL) {
+		*user_sess_key = data_blob(NULL, 16);
+		SMBsesskeygen_ntv2(kr, value_from_encryption, user_sess_key->data);
+	}
+
+#if DEBUG_PASSWORD
+	DEBUG(100,("Part password (P16) was |\n"));
+	dump_data(100, part_passwd, 16);
+	DEBUGADD(100,("Password from client was |\n"));
+	dump_data(100, ntv2_response->data, ntv2_response->length);
+	DEBUGADD(100,("Variable data from client was |\n"));
+	dump_data(100, client_key_data.data, client_key_data.length);
+	DEBUGADD(100,("Given challenge was |\n"));
+	dump_data(100, sec_blob->data, sec_blob->length);
+	DEBUGADD(100,("Value from encryption was |\n"));
+	dump_data(100, value_from_encryption, 16);
+#endif
+	data_blob_clear_free(&client_key_data);
+	return (memcmp(value_from_encryption, client_response, 16) == 0);
+}
+
+/**
+ * Check a challenge-response password against the value of the NT or
+ * LM password hash.
+ *
+ * @param mem_ctx talloc context
+ * @param challenge 8-byte challenge.  If all zero, forces plaintext comparison
+ * @param nt_response 'unicode' NT response to the challenge, or unicode password
+ * @param lm_response ASCII or LANMAN response to the challenge, or password in DOS code page
+ * @param username internal Samba username, for log messages
+ * @param client_username username the client used
+ * @param client_domain domain name the client used (may be mapped)
+ * @param nt_pw MD4 unicode password from our passdb or similar
+ * @param lm_pw LANMAN ASCII password from our passdb or similar
+ * @param user_sess_key User session key
+ * @param lm_sess_key LM session key (first 8 bytes of the LM hash)
+ */
+
+NTSTATUS ntlm_password_check(TALLOC_CTX *mem_ctx,
+			     const DATA_BLOB *challenge,
+			     const DATA_BLOB *lm_response,
+			     const DATA_BLOB *nt_response,
+			     const char *username, 
+			     const char *client_username, 
+			     const char *client_domain,
+			     const uint8 *lm_pw, const uint8 *nt_pw, 
+			     DATA_BLOB *user_sess_key, 
+			     DATA_BLOB *lm_sess_key)
+{
+	static const unsigned char zeros[8];
+	if (nt_pw == NULL) {
+		DEBUG(3,("ntlm_password_check: NO NT password stored for user %s.\n", 
+			 username));
+	}
+
+	/* Check for cleartext netlogon. Used by Exchange 5.5. */
+	if (challenge->length == sizeof(zeros) && 
+	    (memcmp(challenge->data, zeros, challenge->length) == 0 )) {
+
+		DEBUG(4,("ntlm_password_check: checking plaintext passwords for user %s\n",
+			 username));
+		if (nt_pw && nt_response->length) {
+			unsigned char pwhash[16];
+			mdfour(pwhash, nt_response->data, nt_response->length);
+			if (memcmp(pwhash, nt_pw, sizeof(pwhash)) == 0) {
+				return NT_STATUS_OK;
+			} else {
+				DEBUG(3,("ntlm_password_check: NT (Unicode) plaintext password check failed for user %s\n",
+					 username));
+				return NT_STATUS_WRONG_PASSWORD;
+			}
+
+		} else if (!lp_lanman_auth()) {
+			DEBUG(3,("ntlm_password_check: (plaintext password check) LANMAN passwords NOT PERMITTED for user %s\n",
+				 username));
+
+		} else if (lm_pw && lm_response->length) {
+			uchar dospwd[14]; 
+			uchar p16[16]; 
+			ZERO_STRUCT(dospwd);
+			
+			memcpy(dospwd, lm_response->data, MIN(lm_response->length, sizeof(dospwd)));
+			/* Only the fisrt 14 chars are considered, password need not be null terminated. */
+
+			/* we *might* need to upper-case the string here */
+			E_P16((const unsigned char *)dospwd, p16);
+
+			if (memcmp(p16, lm_pw, sizeof(p16)) == 0) {
+				return NT_STATUS_OK;
+			} else {
+				DEBUG(3,("ntlm_password_check: LANMAN (ASCII) plaintext password check failed for user %s\n",
+					 username));
+				return NT_STATUS_WRONG_PASSWORD;
+			}
+		} else {
+			DEBUG(3, ("Plaintext authentication for user %s attempted, but neither NT nor LM passwords available\n", username));
+			return NT_STATUS_WRONG_PASSWORD;
+		}
+	}
+
+	if (nt_response->length != 0 && nt_response->length < 24) {
+		DEBUG(2,("ntlm_password_check: invalid NT password length (%lu) for user %s\n", 
+			 (unsigned long)nt_response->length, username));		
+	}
+	
+	if (nt_response->length >= 24 && nt_pw) {
+		if (nt_response->length > 24) {
+			/* We have the NT MD4 hash challenge available - see if we can
+			   use it (ie. does it exist in the smbpasswd file).
+			*/
+			DEBUG(4,("ntlm_password_check: Checking NTLMv2 password with domain [%s]\n", client_domain));
+			if (smb_pwd_check_ntlmv2( nt_response, 
+						  nt_pw, challenge, 
+					  client_username, 
+						  client_domain,
+						  user_sess_key)) {
+				return NT_STATUS_OK;
+			}
+			
+			DEBUG(4,("ntlm_password_check: Checking NTLMv2 password without a domain\n"));
+			if (smb_pwd_check_ntlmv2( nt_response, 
+						  nt_pw, challenge, 
+						  client_username, 
+						  "",
+						  user_sess_key)) {
+				return NT_STATUS_OK;
+			} else {
+				DEBUG(3,("ntlm_password_check: NTLMv2 password check failed\n"));
+				return NT_STATUS_WRONG_PASSWORD;
+			}
+		}
+
+		if (lp_ntlm_auth()) {		
+			/* We have the NT MD4 hash challenge available - see if we can
+			   use it (ie. does it exist in the smbpasswd file).
+			*/
+			DEBUG(4,("ntlm_password_check: Checking NT MD4 password\n"));
+			if (smb_pwd_check_ntlmv1(nt_response, 
+						 nt_pw, challenge,
+						 user_sess_key)) {
+				/* The LM session key for this response is not very secure, 
+				   so use it only if we otherwise allow LM authentication */
+
+				if (lp_lanman_auth() && lm_pw) {
+					uint8 first_8_lm_hash[16];
+					memcpy(first_8_lm_hash, lm_pw, 8);
+					memset(first_8_lm_hash + 8, '\0', 8);
+					*lm_sess_key = data_blob(first_8_lm_hash, 16);
+				}
+				return NT_STATUS_OK;
+			} else {
+				DEBUG(3,("ntlm_password_check: NT MD4 password check failed for user %s\n",
+					 username));
+				return NT_STATUS_WRONG_PASSWORD;
+			}
+		} else {
+			DEBUG(2,("ntlm_password_check: NTLMv1 passwords NOT PERMITTED for user %s\n",
+				 username));			
+			/* no return, becouse we might pick up LMv2 in the LM field */
+		}
+	}
+	
+	if (lm_response->length == 0) {
+		DEBUG(3,("ntlm_password_check: NEITHER LanMan nor NT password supplied for user %s\n",
+			 username));
+		return NT_STATUS_WRONG_PASSWORD;
+	}
+	
+	if (lm_response->length < 24) {
+		DEBUG(2,("ntlm_password_check: invalid LanMan password length (%lu) for user %s\n", 
+			 (unsigned long)nt_response->length, username));		
+		return NT_STATUS_WRONG_PASSWORD;
+	}
+		
+	if (!lp_lanman_auth()) {
+		DEBUG(3,("ntlm_password_check: Lanman passwords NOT PERMITTED for user %s\n",
+			 username));
+	} else if (!lm_pw) {
+		DEBUG(3,("ntlm_password_check: NO LanMan password set for user %s (and no NT password supplied)\n",
+			 username));
+	} else {
+		DEBUG(4,("ntlm_password_check: Checking LM password\n"));
+		if (smb_pwd_check_ntlmv1(lm_response, 
+					 lm_pw, challenge,
+					 NULL)) {
+			uint8 first_8_lm_hash[16];
+			memcpy(first_8_lm_hash, lm_pw, 8);
+			memset(first_8_lm_hash + 8, '\0', 8);
+			*user_sess_key = data_blob(first_8_lm_hash, 16);
+			*lm_sess_key = data_blob(first_8_lm_hash, 16);
+			return NT_STATUS_OK;
+		}
+	}
+	
+	if (!nt_pw) {
+		DEBUG(4,("ntlm_password_check: LM password check failed for user, no NT password %s\n",username));
+		return NT_STATUS_WRONG_PASSWORD;
+	}
+	
+	/* This is for 'LMv2' authentication.  almost NTLMv2 but limited to 24 bytes.
+	   - related to Win9X, legacy NAS pass-though authentication
+	*/
+	DEBUG(4,("ntlm_password_check: Checking LMv2 password with domain %s\n", client_domain));
+	if (smb_pwd_check_ntlmv2( lm_response, 
+				  nt_pw, challenge, 
+				  client_username,
+				  client_domain,
+				  NULL)) {
+		return NT_STATUS_OK;
+	}
+	
+	DEBUG(4,("ntlm_password_check: Checking LMv2 password without a domain\n"));
+	if (smb_pwd_check_ntlmv2( lm_response, 
+				  nt_pw, challenge, 
+				  client_username,
+				  "",
+				  NULL)) {
+		return NT_STATUS_OK;
+	}
+
+	/* Apparently NT accepts NT responses in the LM field
+	   - I think this is related to Win9X pass-though authentication
+	*/
+	DEBUG(4,("ntlm_password_check: Checking NT MD4 password in LM field\n"));
+	if (lp_ntlm_auth()) {
+		if (smb_pwd_check_ntlmv1(lm_response, 
+					 nt_pw, challenge,
+					 NULL)) {
+			/* The session key for this response is still very odd.  
+			   It not very secure, so use it only if we otherwise 
+			   allow LM authentication */
+
+			if (lp_lanman_auth() && lm_pw) {
+				uint8 first_8_lm_hash[16];
+				memcpy(first_8_lm_hash, lm_pw, 8);
+				memset(first_8_lm_hash + 8, '\0', 8);
+				*user_sess_key = data_blob(first_8_lm_hash, 16);
+				*lm_sess_key = data_blob(first_8_lm_hash, 16);
+			}
+			return NT_STATUS_OK;
+		}
+		DEBUG(3,("ntlm_password_check: LM password, NT MD4 password in LM field and LMv2 failed for user %s\n",username));
+	} else {
+		DEBUG(3,("ntlm_password_check: LM password and LMv2 failed for user %s, and NT MD4 password in LM field not permitted\n",username));
+	}
+	return NT_STATUS_WRONG_PASSWORD;
+}
+
diff --git a/source3/utils/ntlm_auth.c b/source3/utils/ntlm_auth.c
index e33f4c4dee..8c02b2741a 100644
--- a/source3/utils/ntlm_auth.c
+++ b/source3/utils/ntlm_auth.c
@@ -24,6 +24,8 @@
 
 #include "includes.h"
 
+#undef HAVE_KRB5
+
 #undef DBGC_CLASS
 #define DBGC_CLASS DBGC_WINBIND
 
@@ -33,6 +35,7 @@ enum stdio_helper_mode {
 	SQUID_2_4_BASIC,
 	SQUID_2_5_BASIC,
 	SQUID_2_5_NTLMSSP,
+	CLIENT_NTLMSSP_1,
 	GSS_SPNEGO,
 	GSS_SPNEGO_CLIENT,
 	NUM_HELPER_MODES
@@ -55,6 +58,9 @@ static void manage_squid_basic_request (enum stdio_helper_mode stdio_helper_mode
 static void manage_squid_ntlmssp_request (enum stdio_helper_mode stdio_helper_mode, 
 					  char *buf, int length);
 
+static void manage_client_ntlmssp_request (enum stdio_helper_mode stdio_helper_mode, 
+					   char *buf, int length);
+
 static void manage_gss_spnego_request (enum stdio_helper_mode stdio_helper_mode, 
 				       char *buf, int length);
 
@@ -69,6 +75,7 @@ static const struct {
 	{ SQUID_2_4_BASIC, "squid-2.4-basic", manage_squid_basic_request},
 	{ SQUID_2_5_BASIC, "squid-2.5-basic", manage_squid_basic_request},
 	{ SQUID_2_5_NTLMSSP, "squid-2.5-ntlmssp", manage_squid_ntlmssp_request},
+	{ CLIENT_NTLMSSP_1, "client-ntlmssp-1", manage_client_ntlmssp_request},
 	{ GSS_SPNEGO, "gss-spnego", manage_gss_spnego_request},
 	{ GSS_SPNEGO_CLIENT, "gss-spnego-client", manage_gss_spnego_client_request},
 	{ NUM_HELPER_MODES, NULL, NULL}
@@ -335,6 +342,112 @@ static NTSTATUS winbind_pw_check(struct ntlmssp_state *ntlmssp_state, DATA_BLOB
 	return nt_status;
 }
 
+static NTSTATUS local_pw_check(struct ntlmssp_state *ntlmssp_state, DATA_BLOB *nt_session_key, DATA_BLOB *lm_session_key) 
+{
+	static const char zeros[16];
+	NTSTATUS nt_status;
+	uint8 lm_key[8]; 
+	uint8 nt_key[16]; 
+	uint8 lm_pw[16], nt_pw[16];
+
+	nt_lm_owf_gen (opt_password, nt_pw, lm_pw);
+	
+	nt_status = ntlm_password_check(ntlmssp_state->mem_ctx, 
+					&ntlmssp_state->chal,
+					&ntlmssp_state->lm_resp,
+					&ntlmssp_state->nt_resp, 
+					ntlmssp_state->user, 
+					ntlmssp_state->user, 
+					ntlmssp_state->domain,
+					lm_pw, nt_pw, nt_session_key, lm_session_key);
+	
+	if (NT_STATUS_IS_OK(nt_status)) {
+		if (memcmp(lm_key, zeros, 8) != 0) {
+			*lm_session_key = data_blob(NULL, 16);
+			memcpy(lm_session_key->data, lm_key, 8);
+			memset(lm_session_key->data+8, '\0', 8);
+		}
+		
+		if (memcmp(nt_key, zeros, 16) != 0) {
+			*nt_session_key = data_blob(nt_key, 16);
+		}
+	} else {
+		DEBUG(3, ("Login for user [%s]\\[%s]@[%s] failed due to [%s]\n", 
+			  ntlmssp_state->domain, ntlmssp_state->user, ntlmssp_state->workstation, 
+			  nt_errstr(nt_status)));
+	}
+	return nt_status;
+}
+
+static NTSTATUS ntlm_auth_start_ntlmssp_client(NTLMSSP_STATE **client_ntlmssp_state) 
+{
+	NTSTATUS status;
+	if ( (opt_username == NULL) || (opt_domain == NULL) ) {
+		DEBUG(1, ("Need username and domain for NTLMSSP\n"));
+		return status;
+	}
+
+	status = ntlmssp_client_start(client_ntlmssp_state);
+
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(1, ("Could not start NTLMSSP client: %s\n",
+			  nt_errstr(status)));
+		ntlmssp_end(client_ntlmssp_state);
+		return status;
+	}
+
+	status = ntlmssp_set_username(*client_ntlmssp_state, opt_username);
+
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(1, ("Could not set username: %s\n",
+			  nt_errstr(status)));
+		ntlmssp_end(client_ntlmssp_state);
+		return status;
+	}
+
+	status = ntlmssp_set_domain(*client_ntlmssp_state, opt_domain);
+
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(1, ("Could not set domain: %s\n",
+			  nt_errstr(status)));
+		ntlmssp_end(client_ntlmssp_state);
+		return status;
+	}
+
+	status = ntlmssp_set_password(*client_ntlmssp_state, opt_password);
+	
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(1, ("Could not set password: %s\n",
+			  nt_errstr(status)));
+		ntlmssp_end(client_ntlmssp_state);
+		return status;
+	}
+	return NT_STATUS_OK;
+}
+
+static NTSTATUS ntlm_auth_start_ntlmssp_server(NTLMSSP_STATE **ntlmssp_state) 
+{
+	NTSTATUS status = ntlmssp_server_start(ntlmssp_state);
+	
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(1, ("Could not start NTLMSSP client: %s\n",
+			  nt_errstr(status)));
+		return status;
+	}
+
+	/* Have we been given a local password, or should we ask winbind? */
+	if (opt_password) {
+		(*ntlmssp_state)->check_password = local_pw_check;
+		(*ntlmssp_state)->get_domain = lp_workgroup;
+		(*ntlmssp_state)->get_global_myname = global_myname;
+	} else {
+		(*ntlmssp_state)->check_password = winbind_pw_check;
+		(*ntlmssp_state)->get_domain = get_winbind_domain;
+		(*ntlmssp_state)->get_global_myname = get_winbind_netbios_name;
+	}
+	return NT_STATUS_OK;
+}
+
 static void manage_squid_ntlmssp_request(enum stdio_helper_mode stdio_helper_mode, 
 					 char *buf, int length) 
 {
@@ -348,6 +461,29 @@ static void manage_squid_ntlmssp_request(enum stdio_helper_mode stdio_helper_mod
 		return;
 	}
 
+	if (strlen(buf) > 3) {
+		request = base64_decode_data_blob(buf + 3);
+	} else {
+		request = data_blob(NULL, 0);
+	}
+
+	if ((strncmp(buf, "PW ", 3) == 0)) {
+		/* The calling application wants us to use a local password (rather than winbindd) */
+
+		opt_password = strndup((const char *)request.data, request.length);
+
+		if (opt_password == NULL) {
+			DEBUG(1, ("Out of memory\n"));
+			x_fprintf(x_stdout, "BH\n");
+			data_blob_free(&request);
+			return;
+		}
+
+		x_fprintf(x_stdout, "OK\n");
+		data_blob_free(&request);
+		return;
+	}
+
 	if (strncmp(buf, "YR", 2) == 0) {
 		if (ntlmssp_state)
 			ntlmssp_end(&ntlmssp_state);
@@ -359,17 +495,11 @@ static void manage_squid_ntlmssp_request(enum stdio_helper_mode stdio_helper_mod
 		return;
 	}
 
-	if (strlen(buf) > 3) {
-		request = base64_decode_data_blob(buf + 3);
-	} else {
-		request = data_blob(NULL, 0);
-	}
-
 	if (!ntlmssp_state) {
-		ntlmssp_server_start(&ntlmssp_state);
-		ntlmssp_state->check_password = winbind_pw_check;
-		ntlmssp_state->get_domain = get_winbind_domain;
-		ntlmssp_state->get_global_myname = get_winbind_netbios_name;
+		if (!NT_STATUS_IS_OK(nt_status = ntlm_auth_start_ntlmssp_server(&ntlmssp_state))) {
+			x_fprintf(x_stdout, "BH %s\n", nt_errstr(nt_status));
+			return;
+		}
 	}
 
 	DEBUG(10, ("got NTLMSSP packet:\n"));
@@ -386,6 +516,8 @@ static void manage_squid_ntlmssp_request(enum stdio_helper_mode stdio_helper_mod
 	} else if (NT_STATUS_EQUAL(nt_status, NT_STATUS_ACCESS_DENIED)) {
 		x_fprintf(x_stdout, "BH %s\n", nt_errstr(nt_status));
 		DEBUG(0, ("NTLMSSP BH: %s\n", nt_errstr(nt_status)));
+
+		ntlmssp_end(&ntlmssp_state);
 	} else if (!NT_STATUS_IS_OK(nt_status)) {
 		x_fprintf(x_stdout, "NA %s\n", nt_errstr(nt_status));
 		DEBUG(10, ("NTLMSSP %s\n", nt_errstr(nt_status)));
@@ -397,6 +529,102 @@ static void manage_squid_ntlmssp_request(enum stdio_helper_mode stdio_helper_mod
 	data_blob_free(&request);
 }
 
+static void manage_client_ntlmssp_request(enum stdio_helper_mode stdio_helper_mode, 
+					 char *buf, int length) 
+{
+	static NTLMSSP_STATE *ntlmssp_state = NULL;
+	DATA_BLOB request, reply;
+	NTSTATUS nt_status;
+	BOOL first = False;
+	
+	if (strlen(buf) < 2) {
+		DEBUG(1, ("NTLMSSP query [%s] invalid", buf));
+		x_fprintf(x_stdout, "BH\n");
+		return;
+	}
+
+	if (strlen(buf) > 3) {
+		request = base64_decode_data_blob(buf + 3);
+	} else {
+		request = data_blob(NULL, 0);
+	}
+
+	if (strncmp(buf, "PW ", 3) == 0) {
+		/* We asked for a password and obviously got it :-) */
+
+		opt_password = strndup((const char *)request.data, request.length);
+
+		if (opt_password == NULL) {
+			DEBUG(1, ("Out of memory\n"));
+			x_fprintf(x_stdout, "BH\n");
+			data_blob_free(&request);
+			return;
+		}
+
+		x_fprintf(x_stdout, "OK\n");
+		data_blob_free(&request);
+		return;
+	}
+
+	if (opt_password == NULL) {
+		
+		/* Request a password from the calling process.  After
+		   sending it, the calling process should retry asking for the negotiate. */
+		
+		DEBUG(10, ("Requesting password\n"));
+		x_fprintf(x_stdout, "PW\n");
+		return;
+	}
+
+	if (strncmp(buf, "YR", 2) == 0) {
+		if (ntlmssp_state)
+			ntlmssp_end(&ntlmssp_state);
+	} else if (strncmp(buf, "TT", 2) == 0) {
+		
+	} else {
+		DEBUG(1, ("NTLMSSP query [%s] invalid", buf));
+		x_fprintf(x_stdout, "BH\n");
+		return;
+	}
+
+	if (!ntlmssp_state) {
+		if (!NT_STATUS_IS_OK(nt_status = ntlm_auth_start_ntlmssp_client(&ntlmssp_state))) {
+			x_fprintf(x_stdout, "BH %s\n", nt_errstr(nt_status));
+			return;
+		}
+		first = True;
+	}
+
+	DEBUG(10, ("got NTLMSSP packet:\n"));
+	dump_data(10, (const char *)request.data, request.length);
+
+	nt_status = ntlmssp_update(ntlmssp_state, request, &reply);
+	
+	if (NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
+		char *reply_base64 = base64_encode_data_blob(reply);
+		if (first) {
+			x_fprintf(x_stdout, "YR %s\n", reply_base64);
+		} else { 
+			x_fprintf(x_stdout, "KK %s\n", reply_base64);
+		}
+		SAFE_FREE(reply_base64);
+		data_blob_free(&reply);
+		DEBUG(10, ("NTLMSSP challenge\n"));
+	} else if (NT_STATUS_IS_OK(nt_status)) {
+		x_fprintf(x_stdout, "AF\n");
+		DEBUG(10, ("NTLMSSP OK!\n"));
+		if (ntlmssp_state)
+			ntlmssp_end(&ntlmssp_state);
+	} else {
+		x_fprintf(x_stdout, "BH %s\n", nt_errstr(nt_status));
+		DEBUG(0, ("NTLMSSP BH: %s\n", nt_errstr(nt_status)));
+		if (ntlmssp_state)
+			ntlmssp_end(&ntlmssp_state);
+	}
+
+	data_blob_free(&request);
+}
+
 static void manage_squid_basic_request(enum stdio_helper_mode stdio_helper_mode, 
 				       char *buf, int length) 
 {
@@ -561,10 +789,10 @@ static void manage_gss_spnego_request(enum stdio_helper_mode stdio_helper_mode,
 				return;
 			}
 
-			ntlmssp_server_start(&ntlmssp_state);
-			ntlmssp_state->check_password = winbind_pw_check;
-			ntlmssp_state->get_domain = get_winbind_domain;
-			ntlmssp_state->get_global_myname = get_winbind_netbios_name;
+			if (!NT_STATUS_IS_OK(status = ntlm_auth_start_ntlmssp_server(&ntlmssp_state))) {
+				x_fprintf(x_stdout, "BH %s\n", nt_errstr(status));
+				return;
+			}
 
 			DEBUG(10, ("got NTLMSSP packet:\n"));
 			dump_data(10, (const char *)request.negTokenInit.mechToken.data,
@@ -720,11 +948,14 @@ static BOOL manage_client_ntlmssp_init(SPNEGO_DATA spnego)
 		return False;
 	}
 
-	if ( (opt_username == NULL) || (opt_domain == NULL) ) {
-		DEBUG(1, ("Need username and domain for NTLMSSP\n"));
-		return False;
+	if (!client_ntlmssp_state) {
+		if (!NT_STATUS_IS_OK(status = ntlm_auth_start_ntlmssp_client(&client_ntlmssp_state))) {
+			x_fprintf(x_stdout, "BH %s\n", nt_errstr(status));
+			return False;
+		}
 	}
 
+
 	if (opt_password == NULL) {
 
 		/* Request a password from the calling process.  After
@@ -736,42 +967,6 @@ static BOOL manage_client_ntlmssp_init(SPNEGO_DATA spnego)
 		return True;
 	}
 
-	status = ntlmssp_client_start(&client_ntlmssp_state);
-
-	if (!NT_STATUS_IS_OK(status)) {
-		DEBUG(1, ("Could not start NTLMSSP client: %s\n",
-			  nt_errstr(status)));
-		ntlmssp_end(&client_ntlmssp_state);
-		return False;
-	}
-
-	status = ntlmssp_set_username(client_ntlmssp_state, opt_username);
-
-	if (!NT_STATUS_IS_OK(status)) {
-		DEBUG(1, ("Could not set username: %s\n",
-			  nt_errstr(status)));
-		ntlmssp_end(&client_ntlmssp_state);
-		return False;
-	}
-
-	status = ntlmssp_set_domain(client_ntlmssp_state, opt_domain);
-
-	if (!NT_STATUS_IS_OK(status)) {
-		DEBUG(1, ("Could not set domain: %s\n",
-			  nt_errstr(status)));
-		ntlmssp_end(&client_ntlmssp_state);
-		return False;
-	}
-
-	status = ntlmssp_set_password(client_ntlmssp_state, opt_password);
-	
-	if (!NT_STATUS_IS_OK(status)) {
-		DEBUG(1, ("Could not set password: %s\n",
-			  nt_errstr(status)));
-		ntlmssp_end(&client_ntlmssp_state);
-		return False;
-	}
-
 	spnego.type = SPNEGO_NEG_TOKEN_INIT;
 	spnego.negTokenInit.mechTypes = my_mechs;
 	spnego.negTokenInit.reqFlags = 0;
@@ -1915,7 +2110,12 @@ enum {
 				exit(0);
 			}
 		}
-		x_fprintf(x_stderr, "unknown helper protocol [%s]\n", helper_protocol);
+		x_fprintf(x_stderr, "unknown helper protocol [%s]\n\nValid helper protools:\n\n", helper_protocol);
+
+		for (i=0; i<NUM_HELPER_MODES; i++) {
+			x_fprintf(x_stderr, "%s\n", stdio_helper_protocols[i].name);
+		}
+
 		exit(1);
 	}