CVE-2015-5296: s3:libsmb: force signing when requiring encryption in SMBC_server_inte...

BUG: https://bugzilla.samba.org/show_bug.cgi?id=11536

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>

diff --git a/source3/libsmb/libsmb_server.c b/source3/libsmb/libsmb_server.c
index 07d51ea00cb0e551711d6264b24c97b4ef090ad3..2abd37e12f05685f5a2c61727cbb73dfb60fec1f 100644 (file)
--- a/source3/libsmb/libsmb_server.c
+++ b/source3/libsmb/libsmb_server.c
@@ -273,6 +273,7 @@ SMBC_server_internal(TALLOC_CTX *ctx,
        char *newserver, *newshare;
        int flags = 0;
        struct smbXcli_tcon *tcon = NULL;
+       int signing_state = SMB_SIGNING_DEFAULT;
 
        ZERO_STRUCT(c);
        *in_cache = false;
@@ -439,6 +440,10 @@ SMBC_server_internal(TALLOC_CTX *ctx,
                flags |= CLI_FULL_CONNECTION_USE_NT_HASH;
        }
 
+       if (context->internal->smb_encryption_level != SMBC_ENCRYPTLEVEL_NONE) {
+               signing_state = SMB_SIGNING_REQUIRED;
+       }
+
        if (port == 0) {
                if (share == NULL || *share == '\0' || is_ipc) {
                        /*
@@ -446,7 +451,7 @@ SMBC_server_internal(TALLOC_CTX *ctx,
                         */
                        status = cli_connect_nb(server_n, NULL, NBT_SMB_PORT, 0x20,
                                        smbc_getNetbiosName(context),
-                                       SMB_SIGNING_DEFAULT, flags, &c);
+                                       signing_state, flags, &c);
                }
        }
 
@@ -456,7 +461,7 @@ SMBC_server_internal(TALLOC_CTX *ctx,
                 */
                status = cli_connect_nb(server_n, NULL, port, 0x20,
                                        smbc_getNetbiosName(context),
-                                       SMB_SIGNING_DEFAULT, flags, &c);
+                                       signing_state, flags, &c);
        }
 
        if (!NT_STATUS_IS_OK(status)) {
@@ -737,6 +742,7 @@ SMBC_attr_server(TALLOC_CTX *ctx,
         ipc_srv = SMBC_find_server(ctx, context, server, "*IPC$",
                                    pp_workgroup, pp_username, pp_password);
         if (!ipc_srv) {
+               int signing_state = SMB_SIGNING_DEFAULT;
 
                 /* We didn't find a cached connection.  Get the password */
                if (!*pp_password || (*pp_password)[0] == '\0') {
@@ -758,6 +764,9 @@ SMBC_attr_server(TALLOC_CTX *ctx,
                 if (smbc_getOptionUseCCache(context)) {
                         flags |= CLI_FULL_CONNECTION_USE_CCACHE;
                 }
+               if (context->internal->smb_encryption_level != SMBC_ENCRYPTLEVEL_NONE) {
+                       signing_state = SMB_SIGNING_REQUIRED;
+               }
 
                 nt_status = cli_full_connection(&ipc_cli,
                                                lp_netbios_name(), server,
@@ -766,7 +775,7 @@ SMBC_attr_server(TALLOC_CTX *ctx,
                                                *pp_workgroup,
                                                *pp_password,
                                                flags,
-                                               SMB_SIGNING_DEFAULT);
+                                               signing_state);
                 if (! NT_STATUS_IS_OK(nt_status)) {
                         DEBUG(1,("cli_full_connection failed! (%s)\n",
                                  nt_errstr(nt_status)));