Obscure the password on url dsn too

Note that we don't leak anymore the password length.

Fix #528

NEWS

@@ -7,6 +7,8 @@ What's new in psycopg 2.7.2
 - Fixed inconsistent state in externally closed connections
   (:tickets:`#263, #311, #443`). Was fixed in 2.6.2 but not included in
   2.7 by mistake.
+- Don't display the password in `connection.dsn` when the connection
+  string is specified as an URI (:ticket:`#528`).
 
 
 What's new in psycopg 2.7.1

doc/src/connection.rst

@@ -343,6 +343,9 @@ The ``connection`` class
         Read-only string containing the connection string used by the
         connection.
 
+        If a password was specified in the connection string it will be
+        obscured.
+
 
     .. index::
         pair: Transaction; Autocommit

psycopg/connection_type.c

@@ -1248,20 +1248,53 @@ static struct PyGetSetDef connectionObject_getsets[] = {
 
 /* initialization and finalization methods */
 
-static void
+RAISES_NEG static int
 obscure_password(connectionObject *conn)
 {
-    char *pos;
+    PQconninfoOption *options;
+    PyObject *d = NULL, *v = NULL, *dsn = NULL;
+    char *tmp;
+    int rv = -1;
 
     if (!conn || !conn->dsn) {
-        return;
+        return 0;
     }
 
-    pos = strstr(conn->dsn, "password");
-    if (pos != NULL) {
-        for (pos = pos+9 ; *pos != '\0' && *pos != ' '; pos++)
-            *pos = 'x';
+    if (!(options = PQconninfoParse(conn->dsn, NULL))) {
+        /* unlikely: the dsn was already tested valid */
+        return 0;
     }
+
+    if (!(d = psycopg_dict_from_conninfo_options(
+            options, /* include_password = */ 1))) {
+        goto exit;
+    }
+    if (NULL == PyDict_GetItemString(d, "password")) {
+        /* the dsn doesn't have a password */
+        rv = 0;
+        goto exit;
+    }
+
+    /* scrub the password and put back the connection string together */
+    if (!(v = Text_FromUTF8("xxx"))) { goto exit; }
+    if (0 > PyDict_SetItemString(d, "password", v)) { goto exit; }
+    if (!(dsn = psycopg_make_dsn(Py_None, d))) { goto exit; }
+    if (!(dsn = psycopg_ensure_bytes(dsn))) { goto exit; }
+
+    /* Replace the connection string on the connection object */
+    tmp = conn->dsn;
+    psycopg_strdup(&conn->dsn, Bytes_AS_STRING(dsn), -1);
+    PyMem_Free(tmp);
+
+    rv = 0;
+
+exit:
+    PQconninfoFree(options);
+    Py_XDECREF(v);
+    Py_XDECREF(d);
+    Py_XDECREF(dsn);
+
+    return rv;
 }
 
 static int
@@ -1303,7 +1336,12 @@ connection_setup(connectionObject *self, const char *dsn, long int async)
 
 exit:
     /* here we obfuscate the password even if there was a connection error */
-    obscure_password(self);
+    {
+        PyObject *ptype = NULL, *pvalue = NULL, *ptb = NULL;
+        PyErr_Fetch(&ptype, &pvalue, &ptb);
+        obscure_password(self);
+        PyErr_Restore(ptype, pvalue, ptb);
+    }
     return res;
 }
 

psycopg/psycopg.h

@@ -142,6 +142,8 @@ STEALS(1) HIDDEN PyObject * psycopg_ensure_text(PyObject *obj);
 HIDDEN PyObject *psycopg_dict_from_conninfo_options(PQconninfoOption *options,
               int include_password);
 
+HIDDEN PyObject *psycopg_make_dsn(PyObject *dsn, PyObject *kwargs);
+
 /* Exceptions docstrings */
 #define Error_doc \
 "Base class for error exceptions."

psycopg/utils.c

@@ -280,6 +280,30 @@ exit:
 }
 
 
+/* Make a connection string out of a string and a dictionary of arguments.
+ *
+ * Helper to call psycopg2.extensions.make_dns()
+ */
+PyObject *
+psycopg_make_dsn(PyObject *dsn, PyObject *kwargs)
+{
+    PyObject *ext = NULL, *make_dsn = NULL;
+    PyObject *args = NULL, *rv = NULL;
+
+    if (!(ext = PyImport_ImportModule("psycopg2.extensions"))) { goto exit; }
+    if (!(make_dsn = PyObject_GetAttrString(ext, "make_dsn"))) { goto exit; }
+
+    if (!(args = PyTuple_Pack(1, dsn))) { goto exit; }
+    rv = PyObject_Call(make_dsn, args, kwargs);
+
+exit:
+    Py_XDECREF(args);
+    Py_XDECREF(make_dsn);
+    Py_XDECREF(ext);
+
+    return rv;
+}
+
 /* Convert a C string into Python Text using a specified codec.
  *
  * The codec is the python function codec.getdecoder(enc). It is only used on

tests/test_connection.py

@@ -1504,19 +1504,16 @@ class PasswordLeakTestCase(ConnectingTestCase):
     def test_leak(self):
         self.assertRaises(psycopg2.DatabaseError,
             self.GrassingConnection, "dbname=nosuch password=whateva")
+        self.assertDsnEqual(self.dsn, "dbname=nosuch password=xxx")
 
-        self.assert_('nosuch' in self.dsn)
-        self.assert_('password' in self.dsn)
-        self.assert_('whateva' not in self.dsn)
-
+    @skip_before_libpq(9, 2)
     def test_url_leak(self):
         self.assertRaises(psycopg2.DatabaseError,
             self.GrassingConnection,
             "postgres://someone:whateva@localhost/nosuch")
 
-        self.assert_('nosuch' in self.dsn)
-        self.assert_('someone' in self.dsn)
-        self.assert_('whateva' not in self.dsn)
+        self.assertDsnEqual(self.dsn,
+            "user=someone password=xxx host=localhost dbname=nosuch")
 
 
 def test_suite():