Patch from Luke Howard to add mutual kerberos authentication, and SMB session

keys for kerberos authentication.

Andrew Bartlett
(This used to be commit 8b798f03dbbdd670ff9af4eb46f7b0845c611e0f)

8 files changed, 157 insertions, 42 deletions

diff --git a/source3/configure.in b/source3/configure.in
index 66bdf5edf1..e3b5f2fe15 100644
--- a/source3/configure.in
+++ b/source3/configure.in
@@ -2250,6 +2250,22 @@ if test x"$samba_cv_HAVE_KRB5_TKT_ENC_PART2" = x"yes"; then
     AC_DEFINE(HAVE_KRB5_TKT_ENC_PART2,1,[Whether the krb5_ticket struct has a enc_part2 property])
 fi
 
+AC_CACHE_CHECK([for keyvalue in krb5_keyblock],samba_cv_HAVE_KRB5_KEYBLOCK_KEYVALUE,[
+AC_TRY_COMPILE([#include <krb5.h>],
+[krb5_keyblock key; key.keyvalue.data = NULL;],
+samba_cv_HAVE_KRB5_KEYBLOCK_KEYVALUE=yes,samba_cv_HAVE_KRB5_KEYBLOCK_KEYVALUE=no)])
+if test x"$samba_cv_HAVE_KRB5_KEYBLOCK_KEYVALUE" = x"yes"; then
+    AC_DEFINE(HAVE_KRB5_KEYBLOCK_KEYVALUE,1,[Whether the krb5_keyblock struct has a keyvalue property])
+fi
+
+AC_CACHE_CHECK([for ENCTYPE_ARCFOUR_HMAC_MD5],samba_cv_HAVE_ENCTYPE_ARCFOUR_HMAC_MD5,[
+AC_TRY_COMPILE([#include <krb5.h>],
+[krb5_enctype enctype; enctype = ENCTYPE_ARCFOUR_HMAC_MD5;],
+samba_cv_HAVE_ENCTYPE_ARCFOUR_HMAC_MD5=yes,samba_cv_HAVE_ENCTYPE_ARCFOUR_HMAC_MD5=no)])
+if test x"$samba_cv_HAVE_ENCTYPE_ARCFOUR_HMAC_MD5" = x"yes"; then
+    AC_DEFINE(HAVE_ENCTYPE_ARCFOUR_HMAC_MD5,1,[Whether the ENCTYPE_ARCFOUR_HMAC_MD5 key type is available])
+fi
+
   ########################################################
   # now see if we can find the krb5 libs in standard paths
   # or as specified above
diff --git a/source3/include/ads.h b/source3/include/ads.h
index 304a997b2c..f90983e405 100644
--- a/source3/include/ads.h
+++ b/source3/include/ads.h
@@ -208,3 +208,8 @@ typedef void **ADS_MODLIST;
 
 /* Kerberos environment variable names */
 #define KRB5_ENV_CCNAME "KRB5CCNAME"
+
+/* Heimdal uses a slightly different name */
+#if defined(HAVE_ENCTYPE_ARCFOUR_HMAC_MD5)
+#define ENCTYPE_ARCFOUR_HMAC ENCTYPE_ARCFOUR_HMAC_MD5
+#endif
diff --git a/source3/include/asn_1.h b/source3/include/asn_1.h
index ab7fa5d398..7d4da0db0c 100644
--- a/source3/include/asn_1.h
+++ b/source3/include/asn_1.h
@@ -59,4 +59,11 @@ typedef struct {
 #define SPNEGO_NEG_RESULT_INCOMPLETE 1
 #define SPNEGO_NEG_RESULT_REJECT 2
 
+/* not really ASN.1, but RFC 1964 */
+#define TOK_ID_KRB_AP_REQ	"\x01\x00"
+#define TOK_ID_KRB_AP_REP	"\x02\x00"
+#define TOK_ID_KRB_ERROR	"\x03\x00"
+#define TOK_ID_GSS_GETMIC	"\x01\x01"
+#define TOK_ID_GSS_WRAP		"\x02\x01"
+
 #endif /* _ASN_1_H */
diff --git a/source3/libads/kerberos_verify.c b/source3/libads/kerberos_verify.c
index 17fecf60c8..4d9a1bf765 100644
--- a/source3/libads/kerberos_verify.c
+++ b/source3/libads/kerberos_verify.c
@@ -3,7 +3,7 @@
    kerberos utility library
    Copyright (C) Andrew Tridgell 2001
    Copyright (C) Remus Koos 2001
-   
+   Copyright (C) Luke Howard 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
@@ -29,7 +29,9 @@
   authorization_data if available 
 */
 NTSTATUS ads_verify_ticket(ADS_STRUCT *ads, const DATA_BLOB *ticket, 
-			   char **principal, DATA_BLOB *auth_data)
+			   char **principal, DATA_BLOB *auth_data,
+			   DATA_BLOB *ap_rep,
+			   uint8 session_key[16])
 {
 	krb5_context context;
 	krb5_auth_context auth_context = NULL;
@@ -122,10 +124,24 @@ NTSTATUS ads_verify_ticket(ADS_STRUCT *ads, const DATA_BLOB *ticket,
 	if (!auth_ok) {
 		DEBUG(3,("krb5_rd_req with auth failed (%s)\n", 
 			 error_message(ret)));
-		SAFE_FREE(key);
 		return NT_STATUS_LOGON_FAILURE;
 	}
 
+	ret = krb5_mk_rep(context, auth_context, &packet);
+	if (ret) {
+		DEBUG(3,("Failed to generate mutual authentication reply (%s)\n",
+			error_message(ret)));
+		krb5_auth_con_free(context, auth_context);
+		return NT_STATUS_LOGON_FAILURE;
+	}
+
+	*ap_rep = data_blob(packet.data, packet.length);
+	free(packet.data);
+
+	krb5_get_smb_session_key(context, auth_context, session_key);
+	DEBUG(0,("SMB session key (from ticket) follows:\n"));
+	dump_data(0, session_key, 16);
+
 #if 0
 	file_save("/tmp/ticket.dat", ticket->data, ticket->length);
 #endif
@@ -134,20 +150,24 @@ NTSTATUS ads_verify_ticket(ADS_STRUCT *ads, const DATA_BLOB *ticket,
 
 #if 0
 	if (tkt->enc_part2) {
-		file_save("/tmp/authdata.dat", 
+		file_save("/tmp/authdata.dat",
 			  tkt->enc_part2->authorization_data[0]->contents,
 			  tkt->enc_part2->authorization_data[0]->length);
-	}
 #endif
 
 	if ((ret = krb5_unparse_name(context, get_principal_from_tkt(tkt),
 				     principal))) {
 		DEBUG(3,("krb5_unparse_name failed (%s)\n", 
 			 error_message(ret)));
+		data_blob_free(auth_data);
+		data_blob_free(ap_rep);
+		krb5_auth_con_free(context, auth_context);
 		return NT_STATUS_LOGON_FAILURE;
 	}
 
+	krb5_auth_con_free(context, auth_context);
+
 	return NT_STATUS_OK;
 }
 
-#endif
+#endif /* HAVE_KRB5 */
diff --git a/source3/libsmb/cliconnect.c b/source3/libsmb/cliconnect.c
index 901daf4b09..4962ffa3c9 100644
--- a/source3/libsmb/cliconnect.c
+++ b/source3/libsmb/cliconnect.c
@@ -2,7 +2,7 @@
    Unix SMB/CIFS implementation.
    client connect/disconnect routines
    Copyright (C) Andrew Tridgell 1994-1998
-   Copyright (C) Andrew Barteltt 2001-2003
+   Copyright (C) Andrew Bartlett 2001-2003
    
    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
diff --git a/source3/libsmb/clikrb5.c b/source3/libsmb/clikrb5.c
index bef6998a49..47dec1f171 100644
--- a/source3/libsmb/clikrb5.c
+++ b/source3/libsmb/clikrb5.c
@@ -2,7 +2,7 @@
    Unix SMB/CIFS implementation.
    simple kerberos5 routines for active directory
    Copyright (C) Andrew Tridgell 2001
-   Copyright (C) Luke Howard 2002
+   Copyright (C) Luke Howard 2002-2003
    
    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
@@ -23,6 +23,16 @@
 
 #ifdef HAVE_KRB5
 
+#ifdef HAVE_KRB5_KEYBLOCK_KEYVALUE
+#define KRB5_KEY_TYPE(k)	((k)->keytype)
+#define KRB5_KEY_LENGTH(k)	((k)->keyvalue.length)
+#define KRB5_KEY_DATA(k)	((k)->keyvalue.data)
+#else
+#define	KRB5_KEY_TYPE(k)	((k)->enctype)
+#define KRB5_KEY_LENGTH(k)	((k)->length)
+#define KRB5_KEY_DATA(k)	((k)->contents)
+#endif /* HAVE_KRB5_KEYBLOCK_KEYVALUE */
+
 #ifndef HAVE_KRB5_SET_REAL_TIME
 /*
  * This function is not in the Heimdal mainline.
@@ -124,7 +134,7 @@ krb5_error_code get_kerberos_allowed_etypes(krb5_context context,
 	return krb5_get_default_in_tkt_etypes(context, enctypes);
 }
 #else
- __ERROR_XX_UNKNOWN_GET_ENCTYPES_FUNCTIONS
+#error UNKNOWN_GET_ENCTYPES_FUNCTIONS
 #endif
 
  void free_kerberos_etypes(krb5_context context, 
@@ -305,12 +315,12 @@ DATA_BLOB krb5_get_ticket(const char *principal, time_t time_offset)
 	DATA_BLOB ret;
 	krb5_enctype enc_types[] = {
 #ifdef ENCTYPE_ARCFOUR_HMAC
-		ENCTYPE_ARCFOUR_HMAC, 
-#endif
-				    ENCTYPE_DES_CBC_MD5, 
-				    ENCTYPE_DES_CBC_CRC, 
-				    ENCTYPE_NULL};
-
+		ENCTYPE_ARCFOUR_HMAC,
+#endif 
+		ENCTYPE_DES_CBC_MD5, 
+		ENCTYPE_DES_CBC_CRC, 
+		ENCTYPE_NULL};
+	
 	retval = krb5_init_context(&context);
 	if (retval) {
 		DEBUG(1,("krb5_init_context failed (%s)\n", 
@@ -355,11 +365,39 @@ failed:
 	return data_blob(NULL, 0);
 }
 
+BOOL krb5_get_smb_session_key(krb5_context context, krb5_auth_context auth_context, uint8 session_key[16])
+ {
+	krb5_keyblock *skey;
+	BOOL ret = False;
+
+	memset(session_key, 0, 16);
+
+#ifdef ENCTYPE_ARCFOUR_HMAC
+	if (krb5_auth_con_getremotesubkey(context, auth_context, &skey) == 0 && skey != NULL) {
+		if (KRB5_KEY_TYPE(skey) ==
+		    ENCTYPE_ARCFOUR_HMAC
+		    && KRB5_KEY_LENGTH(skey) == 16) {
+			memcpy(session_key, KRB5_KEY_DATA(skey), KRB5_KEY_LENGTH(skey));
+			ret = True;
+		}
+		krb5_free_keyblock(context, skey);
+	}
+#endif /* ENCTYPE_ARCFOUR_HMAC */
+
+	return ret;
+ }
 #else /* HAVE_KRB5 */
  /* this saves a few linking headaches */
- DATA_BLOB krb5_get_ticket(const char *principal, time_t time_offset)
+DATA_BLOB krb5_get_ticket(const char *principal, time_t time_offset)
  {
 	 DEBUG(0,("NO KERBEROS SUPPORT\n"));
 	 return data_blob(NULL, 0);
  }
+
+BOOL krb5_get_smb_session_key(krb5_context context, krb5_auth_context ac, uint8 session_key[16])
+ {
+	DEBUG(0,("NO KERBEROS SUPPORT\n"));
+	memset(session_key, 0, 16);
+	return False;
+ }
 #endif
diff --git a/source3/libsmb/clispnego.c b/source3/libsmb/clispnego.c
index e93f1855dd..dfa8f80146 100644
--- a/source3/libsmb/clispnego.c
+++ b/source3/libsmb/clispnego.c
@@ -3,6 +3,7 @@
    simple kerberos5/SPNEGO routines
    Copyright (C) Andrew Tridgell 2001
    Copyright (C) Jim McDonough   2002
+   Copyright (C) Luke Howard     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
@@ -259,7 +260,7 @@ BOOL parse_negTokenTarg(DATA_BLOB blob, char *OIDs[ASN1_MAX_OIDS], DATA_BLOB *se
 /*
   generate a krb5 GSS-API wrapper packet given a ticket
 */
-DATA_BLOB spnego_gen_krb5_wrap(DATA_BLOB ticket)
+DATA_BLOB spnego_gen_krb5_wrap(DATA_BLOB ticket, uint8 tok_id[2])
 {
 	ASN1_DATA data;
 	DATA_BLOB ret;
@@ -268,7 +269,8 @@ DATA_BLOB spnego_gen_krb5_wrap(DATA_BLOB ticket)
 
 	asn1_push_tag(&data, ASN1_APPLICATION(0));
 	asn1_write_OID(&data, OID_KERBEROS5);
-	asn1_write_BOOLEAN(&data, 0);
+
+	asn1_write(&data, tok_id, 2);
 	asn1_write(&data, ticket.data, ticket.length);
 	asn1_pop_tag(&data);
 
@@ -286,7 +288,7 @@ DATA_BLOB spnego_gen_krb5_wrap(DATA_BLOB ticket)
 /*
   parse a krb5 GSS-API wrapper packet giving a ticket
 */
-BOOL spnego_parse_krb5_wrap(DATA_BLOB blob, DATA_BLOB *ticket)
+BOOL spnego_parse_krb5_wrap(DATA_BLOB blob, DATA_BLOB *ticket, uint8 tok_id[2])
 {
 	BOOL ret;
 	ASN1_DATA data;
@@ -295,15 +297,15 @@ BOOL spnego_parse_krb5_wrap(DATA_BLOB blob, DATA_BLOB *ticket)
 	asn1_load(&data, blob);
 	asn1_start_tag(&data, ASN1_APPLICATION(0));
 	asn1_check_OID(&data, OID_KERBEROS5);
-	asn1_check_BOOLEAN(&data, 0);
 
 	data_remaining = asn1_tag_remaining(&data);
 
-	if (data_remaining < 1) {
+	if (data_remaining < 3) {
 		data.has_error = True;
 	} else {
-		
-		*ticket = data_blob(data.data, data_remaining);
+		asn1_read(&data, tok_id, 2);
+		data_remaining -= 2;
+		*ticket = data_blob(NULL, data_remaining);
 		asn1_read(&data, ticket->data, ticket->length);
 	}
 
@@ -330,7 +332,7 @@ DATA_BLOB spnego_gen_negTokenTarg(const char *principal, int time_offset)
 	tkt = krb5_get_ticket(principal, time_offset);
 
 	/* wrap that up in a nice GSS-API wrapping */
-	tkt_wrapped = spnego_gen_krb5_wrap(tkt);
+	tkt_wrapped = spnego_gen_krb5_wrap(tkt, TOK_ID_KRB_AP_REQ);
 
 	/* and wrap that in a shiny SPNEGO wrapper */
 	targ = gen_negTokenTarg(krb_mechs, tkt_wrapped);
@@ -438,9 +440,10 @@ BOOL spnego_parse_auth(DATA_BLOB blob, DATA_BLOB *auth)
 }
 
 /*
-  generate a minimal SPNEGO NTLMSSP response packet.  Doesn't contain much.
+  generate a minimal SPNEGO response packet.  Doesn't contain much.
 */
-DATA_BLOB spnego_gen_auth_response(DATA_BLOB *ntlmssp_reply, NTSTATUS nt_status)
+DATA_BLOB spnego_gen_auth_response(DATA_BLOB *reply, NTSTATUS nt_status,
+				   const char *mechOID)
 {
 	ASN1_DATA data;
 	DATA_BLOB ret;
@@ -462,13 +465,13 @@ DATA_BLOB spnego_gen_auth_response(DATA_BLOB *ntlmssp_reply, NTSTATUS nt_status)
 	asn1_write_enumerated(&data, negResult);
 	asn1_pop_tag(&data);
 
-	if (negResult == SPNEGO_NEG_RESULT_INCOMPLETE) {
+	if (reply->data != NULL) {
 		asn1_push_tag(&data,ASN1_CONTEXT(1));
-		asn1_write_OID(&data, OID_NTLMSSP);
+		asn1_write_OID(&data, mechOID);
 		asn1_pop_tag(&data);
 		
 		asn1_push_tag(&data,ASN1_CONTEXT(2));
-		asn1_write_OctetString(&data, ntlmssp_reply->data, ntlmssp_reply->length);
+		asn1_write_OctetString(&data, reply->data, reply->length);
 		asn1_pop_tag(&data);
 	}
 
diff --git a/source3/smbd/sesssetup.c b/source3/smbd/sesssetup.c
index eafe805aba..7e5ec56a27 100644
--- a/source3/smbd/sesssetup.c
+++ b/source3/smbd/sesssetup.c
@@ -4,6 +4,7 @@
    Copyright (C) Andrew Tridgell 1998-2001
    Copyright (C) Andrew Bartlett      2001
    Copyright (C) Jim McDonough        2002
+   Copyright (C) Luke Howard          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
@@ -146,11 +147,14 @@ static int reply_spnego_kerberos(connection_struct *conn,
 	int sess_vuid;
 	NTSTATUS ret;
 	DATA_BLOB auth_data;
+	DATA_BLOB ap_rep, ap_rep_wrapped, response;
 	auth_serversupplied_info *server_info = NULL;
 	ADS_STRUCT *ads;
+	uint8 session_key[16];
+	uint8 tok_id[2];
 	BOOL foreign = False;
 
-	if (!spnego_parse_krb5_wrap(*secblob, &ticket)) {
+	if (!spnego_parse_krb5_wrap(*secblob, &ticket, tok_id)) {
 		return ERROR_NT(NT_STATUS_LOGON_FAILURE);
 	}
 
@@ -162,7 +166,7 @@ static int reply_spnego_kerberos(connection_struct *conn,
 
 	ads->auth.realm = strdup(lp_realm());
 
-	ret = ads_verify_ticket(ads, &ticket, &client, &auth_data);
+	ret = ads_verify_ticket(ads, &ticket, &client, &auth_data, &ap_rep, session_key);
 	if (!NT_STATUS_IS_OK(ret)) {
 		DEBUG(1,("Failed to verify incoming ticket!\n"));	
 		ads_destroy(&ads);
@@ -177,6 +181,7 @@ static int reply_spnego_kerberos(connection_struct *conn,
 	if (!p) {
 		DEBUG(3,("Doesn't look like a valid principal\n"));
 		ads_destroy(&ads);
+		data_blob_free(&ap_rep);
 		return ERROR_NT(NT_STATUS_LOGON_FAILURE);
 	}
 
@@ -184,6 +189,7 @@ static int reply_spnego_kerberos(connection_struct *conn,
 	if (strcasecmp(p+1, ads->auth.realm) != 0) {
 		DEBUG(3,("Ticket for foreign realm %s@%s\n", client, p+1));
 		if (!lp_allow_trusted_domains()) {
+			data_blob_free(&ap_rep);
 			return ERROR_NT(NT_STATUS_LOGON_FAILURE);
 		}
 		foreign = True;
@@ -209,31 +215,51 @@ static int reply_spnego_kerberos(connection_struct *conn,
 
 	if (!pw) {
 		DEBUG(1,("Username %s is invalid on this system\n",user));
+		data_blob_free(&ap_rep);
 		return ERROR_NT(NT_STATUS_NO_SUCH_USER);
 	}
 
 	if (!NT_STATUS_IS_OK(ret = make_server_info_pw(&server_info,pw))) {
 		DEBUG(1,("make_server_info_from_pw failed!\n"));
+		data_blob_free(&ap_rep);
 		return ERROR_NT(ret);
 	}
-	
+
+	/* Copy out the session key from the AP_REQ. */
+	memcpy(server_info->session_key, session_key, sizeof(session_key));
+
 	/* register_vuid keeps the server info */
 	sess_vuid = register_vuid(server_info, user);
 
 	free(user);
 
 	if (sess_vuid == -1) {
-		return ERROR_NT(NT_STATUS_LOGON_FAILURE);
+		ret = NT_STATUS_LOGON_FAILURE;
+	} else {
+		set_message(outbuf,4,0,True);
+		SSVAL(outbuf, smb_vwv3, 0);
+			
+		if (server_info->guest) {
+			SSVAL(outbuf,smb_vwv2,1);
+		}
+		
+		SSVAL(outbuf, smb_uid, sess_vuid);
 	}
 
-	set_message(outbuf,4,0,True);
-	SSVAL(outbuf, smb_vwv3, 0);
-	add_signature(outbuf);
- 
-	SSVAL(outbuf,smb_uid,sess_vuid);
-	SSVAL(inbuf,smb_uid,sess_vuid);
-	
-	return chain_reply(inbuf,outbuf,length,bufsize);
+        /* wrap that up in a nice GSS-API wrapping */
+	if (NT_STATUS_IS_OK(ret)) {
+		ap_rep_wrapped = spnego_gen_krb5_wrap(ap_rep, TOK_ID_KRB_AP_REP);
+	} else {
+		ap_rep_wrapped = data_blob(NULL, 0);
+	}
+	response = spnego_gen_auth_response(&ap_rep_wrapped, ret, OID_KERBEROS5_OLD);
+	reply_sesssetup_blob(conn, outbuf, response, ret);
+
+	data_blob_free(&ap_rep);
+	data_blob_free(&ap_rep_wrapped);
+	data_blob_free(&response);
+
+	return -1; /* already replied */
 }
 #endif
 
@@ -280,7 +306,7 @@ static BOOL reply_spnego_ntlmssp(connection_struct *conn, char *outbuf,
 		}
 	}
 
-        response = spnego_gen_auth_response(ntlmssp_blob, nt_status);
+        response = spnego_gen_auth_response(ntlmssp_blob, nt_status, OID_NTLMSSP);
 	ret = reply_sesssetup_blob(conn, outbuf, response, nt_status);
 	data_blob_free(&response);