s3 swat: Create random nonce in CGI mode

In CGI mode, we don't get access to the user's password, which would
reduce the hash used so far to parameters an attacker can easily guess.
To work around this, read the nonce from secrets.tdb or generate one if
it's not there.
Also populate the C_user field so we can use that for token creation.

Signed-off-by: Kai Blin <kai@samba.org>

diff --git a/source3/web/cgi.c b/source3/web/cgi.c
index 5b35f117c20a6580967f98ac09bfcc0e7cdbef7b..ef1b8562fa7585347cf68ee715a5ecddf07eb58e 100644 (file)
--- a/source3/web/cgi.c
+++ b/source3/web/cgi.c
@@ -23,6 +23,7 @@
 #include "web/swat_proto.h"
 #include "intl/lang_tdb.h"
 #include "auth.h"
+#include "secrets.h"
 
 #define MAX_VARIABLES 10000
 
@@ -325,7 +326,24 @@ static void cgi_web_auth(void)
                exit(0);
        }
 
-       setuid(0);
+       C_user = SMB_STRDUP(user);
+
+       if (!setuid(0)) {
+               C_pass = secrets_fetch_generic("root", "SWAT");
+               if (C_pass == NULL) {
+                       char *tmp_pass = NULL;
+                       tmp_pass = generate_random_password(talloc_tos(),
+                                                           16, 16);
+                       if (tmp_pass == NULL) {
+                               printf("%sFailed to create random nonce for "
+                                      "SWAT session\n<br>%s\n", head, tail);
+                               exit(0);
+                       }
+                       secrets_store_generic("root", "SWAT", tmp_pass);
+                       C_pass = SMB_STRDUP(tmp_pass);
+                       TALLOC_FREE(tmp_pass);
+               }
+       }
        setuid(pwd->pw_uid);
        if (geteuid() != pwd->pw_uid || getuid() != pwd->pw_uid) {
                printf("%sFailed to become user %s - uid=%d/%d<br>%s\n",