Add the capability to set "smb encrypt = required"

on a share (or global) and have the server reply with
ACCESS_DENIED for all non-encrypted traffic (except
that used to query encryption requirements and set
encryption state).
Jeremy.
(This used to be commit d241bfa57729bb934ada6beabf842a2ca7b4f8a2)

5 files changed, 60 insertions, 3 deletions

diff --git a/source3/client/client.c b/source3/client/client.c
index 665a051190..53669bc8d0 100644
--- a/source3/client/client.c
+++ b/source3/client/client.c
@@ -2466,17 +2466,30 @@ static int cmd_posix(void)
 			return 1;
 		}
 	}
+	if (caplow & CIFS_UNIX_TRANSPORT_ENCRYPTION_CAP) {
+		caps = talloc_asprintf_append(caps, "posix_encrypt ");
+		if (!caps) {
+			return 1;
+		}
+	}
+	if (caplow & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP) {
+		caps = talloc_asprintf_append(caps, "mandatory_posix_encrypt ");
+		if (!caps) {
+			return 1;
+		}
+	}
 
 	if (*caps && caps[strlen(caps)-1] == ' ') {
 		caps[strlen(caps)-1] = '\0';
 	}
+
+	d_printf("Server supports CIFS capabilities %s\n", caps);
+
 	if (!cli_set_unix_extensions_capabilities(cli, major, minor, caplow, caphigh)) {
 		d_printf("Can't set UNIX CIFS extensions capabilities. %s.\n", cli_errstr(cli));
 		return 1;
 	}
 
-	d_printf("Selecting server supported CIFS capabilities %s\n", caps);
-
 	if (caplow & CIFS_UNIX_POSIX_PATHNAMES_CAP) {
 		CLI_DIRSEP_CHAR = '/';
 		*CLI_DIRSEP_STR = '/';
diff --git a/source3/include/smb.h b/source3/include/smb.h
index 2ffd530fb0..aca0009688 100644
--- a/source3/include/smb.h
+++ b/source3/include/smb.h
@@ -658,6 +658,7 @@ typedef struct connection_struct {
 	bool used;
 	int num_files_open;
 	unsigned int num_smb_operations; /* Count of smb operations on this tree. */
+	int encrypt_level;
 
 	/* Semantics requested by the client or forced by the server config. */
 	bool case_sensitive;
diff --git a/source3/smbd/process.c b/source3/smbd/process.c
index 1260d52c77..48a6d18bc9 100644
--- a/source3/smbd/process.c
+++ b/source3/smbd/process.c
@@ -1457,6 +1457,16 @@ static void switch_message(uint8 type, struct smb_request *req, int size)
 			reply_doserror(req, ERRSRV, ERRaccess);
 			return;
 		}
+
+		if (conn->encrypt_level == Required && SVAL(req->inbuf,4) != 0x45FF ) {
+			/* An encrypted packet has 0xFF 'E' at offset 4
+			 * which is little endian 0x45FF */
+			uint8 com = CVAL(req->inbuf,smb_com);
+			if (com != SMBtrans2 && com != SMBtranss2) {
+				reply_nterror(req, NT_STATUS_ACCESS_DENIED);
+				return;
+			}
+		}
 		conn->num_smb_operations++;
 	}
 
diff --git a/source3/smbd/service.c b/source3/smbd/service.c
index 8e69a3b381..65fc818144 100644
--- a/source3/smbd/service.c
+++ b/source3/smbd/service.c
@@ -795,6 +795,8 @@ static connection_struct *make_connection_snum(int snum, user_struct *vuser,
 	conn->case_preserve = lp_preservecase(snum);
 	conn->short_case_preserve = lp_shortpreservecase(snum);
 
+	conn->encrypt_level = lp_smb_encrypt(snum);
+
 	conn->veto_list = NULL;
 	conn->hide_list = NULL;
 	conn->veto_oplock_list = NULL;
diff --git a/source3/smbd/trans2.c b/source3/smbd/trans2.c
index ee4787199e..7625eaed7d 100644
--- a/source3/smbd/trans2.c
+++ b/source3/smbd/trans2.c
@@ -2430,6 +2430,16 @@ static void call_trans2qfsinfo(connection_struct *conn,
 
 	info_level = SVAL(params,0);
 
+	if (conn->encrypt_level == Required && SVAL(req->inbuf,4) != 0x45FF ) {
+		if (info_level != SMB_QUERY_CIFS_UNIX_INFO) {
+			DEBUG(0,("call_trans2qfsinfo: encryption required "
+				"and info level 0x%x sent.\n",
+				(unsigned int)info_level));
+			reply_nterror(req, NT_STATUS_ACCESS_DENIED);
+			return;
+		}
+	}
+
 	DEBUG(3,("call_trans2qfsinfo: level = %d\n", info_level));
 
 	if(SMB_VFS_STAT(conn,".",&st)!=0) {
@@ -2736,7 +2746,7 @@ cBytesSector=%u, cUnitTotal=%u, cUnitAvail=%d\n", (unsigned int)bsize, (unsigned
 				return;
 			}
 
-			switch (lp_smb_encrypt(SNUM(conn))) {
+			switch (conn->encrypt_level) {
 			case 0:
 				encrypt_caps = 0;
 				break;
@@ -2968,6 +2978,16 @@ static void call_trans2setfsinfo(connection_struct *conn,
 
 	info_level = SVAL(params,2);
 
+	if (conn->encrypt_level == Required && SVAL(req->inbuf,4) != 0x45FF ) {
+		if (info_level != SMB_REQUEST_TRANSPORT_ENCRYPTION) {
+			DEBUG(0,("call_trans2setfsinfo: encryption required "
+				"and info level 0x%x sent.\n",
+				(unsigned int)info_level));
+			reply_nterror(req, NT_STATUS_ACCESS_DENIED);
+			return;
+		}
+	}
+
 	switch(info_level) {
 		case SMB_SET_CIFS_UNIX_INFO:
 			{
@@ -7060,6 +7080,17 @@ static void handle_trans2(connection_struct *conn, struct smb_request *req,
 		SSVAL(req->inbuf,smb_flg2,req->flags2);
 	}
 
+	if (conn->encrypt_level == Required && SVAL(req->inbuf,4) != 0x45FF ) {
+		if (state->call != TRANSACT2_QFSINFO &&
+				state->call != TRANSACT2_SETFSINFO) {
+			DEBUG(0,("handle_trans2: encryption required "
+				"with call 0x%x\n",
+				(unsigned int)state->call));
+			reply_nterror(req, NT_STATUS_ACCESS_DENIED);
+			return;
+		}
+	}
+
 	/* Now we must call the relevant TRANS2 function */
 	switch(state->call)  {
 	case TRANSACT2_OPEN: