#include "libpq-fe.h"
#include "fmgr.h"
#include "funcapi.h"
+#include "miscadmin.h"
#include "access/tupdesc.h"
#include "access/heapam.h"
#include "catalog/catname.h"
static HeapTuple get_tuple_of_interest(Oid relid, int16 *pkattnums, int16 pknumatts, char **src_pkattvals);
static Oid get_relid_from_relname(text *relname_text);
static char *generate_relation_name(Oid relid);
+static char *connstr_strip_password(const char *connstr);
/* Global */
List *res_id = NIL;
if (connname)
rcon = (remoteConn *) palloc(sizeof(remoteConn));
+
+ /* for non-superusers, check that server requires a password */
+ if (!superuser())
+ {
+ /* this attempt must fail */
+ conn = PQconnectdb(connstr_strip_password(connstr));
+
+ if (PQstatus(conn) == CONNECTION_OK)
+ {
+ PQfinish(conn);
+ if (rcon)
+ pfree(rcon);
+
+ ereport(ERROR,
+ (errcode(ERRCODE_S_R_E_PROHIBITED_SQL_STATEMENT_ATTEMPTED),
+ errmsg("password is required"),
+ errdetail("Non-superuser cannot connect if the server does not request a password."),
+ errhint("Target server's authentication method must be changed.")));
+ }
+ else
+ PQfinish(conn);
+ }
conn = PQconnectdb(connstr);
MemoryContextSwitchTo(oldcontext);
errmsg("undefined connection name")));
}
+
+/*
+ * Modified version of conninfo_parse() from fe-connect.c
+ * Used to remove any password from the connection string
+ * in order to test whether the server auth method will
+ * require it.
+ */
+static char *
+connstr_strip_password(const char *connstr)
+{
+ char *pname;
+ char *pval;
+ char *buf;
+ char *cp;
+ char *cp2;
+ StringInfoData result;
+
+ /* initialize return value */
+ initStringInfo(&result);
+
+ /* Need a modifiable copy of the input string */
+ buf = pstrdup(connstr);
+ cp = buf;
+
+ while (*cp)
+ {
+ /* Skip blanks before the parameter name */
+ if (isspace((unsigned char) *cp))
+ {
+ cp++;
+ continue;
+ }
+
+ /* Get the parameter name */
+ pname = cp;
+ while (*cp)
+ {
+ if (*cp == '=')
+ break;
+ if (isspace((unsigned char) *cp))
+ {
+ *cp++ = '\0';
+ while (*cp)
+ {
+ if (!isspace((unsigned char) *cp))
+ break;
+ cp++;
+ }
+ break;
+ }
+ cp++;
+ }
+
+ /* Check that there is a following '=' */
+ if (*cp != '=')
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("missing \"=\" after \"%s\" in connection string", pname)));
+ *cp++ = '\0';
+
+ /* Skip blanks after the '=' */
+ while (*cp)
+ {
+ if (!isspace((unsigned char) *cp))
+ break;
+ cp++;
+ }
+
+ /* Get the parameter value */
+ pval = cp;
+
+ if (*cp != '\'')
+ {
+ cp2 = pval;
+ while (*cp)
+ {
+ if (isspace((unsigned char) *cp))
+ {
+ *cp++ = '\0';
+ break;
+ }
+ if (*cp == '\\')
+ {
+ cp++;
+ if (*cp != '\0')
+ *cp2++ = *cp++;
+ }
+ else
+ *cp2++ = *cp++;
+ }
+ *cp2 = '\0';
+ }
+ else
+ {
+ cp2 = pval;
+ cp++;
+ for (;;)
+ {
+ if (*cp == '\0')
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("unterminated quoted string in connection string")));
+ if (*cp == '\\')
+ {
+ cp++;
+ if (*cp != '\0')
+ *cp2++ = *cp++;
+ continue;
+ }
+ if (*cp == '\'')
+ {
+ *cp2 = '\0';
+ cp++;
+ break;
+ }
+ *cp2++ = *cp++;
+ }
+ }
+
+ /*
+ * Now we have the name and the value. If it is not a password,
+ * append to the return connstr.
+ */
+ if (strcmp("password", pname) != 0)
+ /* append the value */
+ appendStringInfo(&result, " %s='%s'", pname, pval);
+ }
+
+ return result.data;
+}
+-- dblink_connect now restricts non-superusers to password
+-- authenticated connections
CREATE OR REPLACE FUNCTION dblink_connect (text)
RETURNS text
AS 'MODULE_PATHNAME','dblink_connect'
AS 'MODULE_PATHNAME','dblink_connect'
LANGUAGE 'C' STRICT;
+-- dblink_connect_u allows non-superusers to use
+-- non-password authenticated connections, but initially
+-- privileges are revoked from public
+CREATE OR REPLACE FUNCTION dblink_connect_u (text)
+RETURNS text
+AS 'MODULE_PATHNAME','dblink_connect'
+LANGUAGE C STRICT SECURITY DEFINER;
+
+CREATE OR REPLACE FUNCTION dblink_connect_u (text, text)
+RETURNS text
+AS 'MODULE_PATHNAME','dblink_connect'
+LANGUAGE C STRICT SECURITY DEFINER;
+
+REVOKE ALL ON FUNCTION dblink_connect_u (text) FROM public;
+REVOKE ALL ON FUNCTION dblink_connect_u (text, text) FROM public;
+
CREATE OR REPLACE FUNCTION dblink_disconnect ()
RETURNS text
AS 'MODULE_PATHNAME','dblink_disconnect'
Returns status = "OK"
+Notes
+
+ Only superusers may use dblink_connect to create non-password
+ authenticated connections. If non-superusers need this capability,
+ use dblink_connect_u instead.
+
Example usage
select dblink_connect('dbname=template1');
OK
(1 row)
+==================================================================
+Name
+
+dblink_connect_u -- Opens a persistent connection to a remote database
+
+Synopsis
+
+dblink_connect_u(text connstr)
+dblink_connect_u(text connname, text connstr)
+
+Inputs
+
+ connname
+ if 2 arguments are given, the first is used as a name for a persistent
+ connection
+
+ connstr
+
+ standard libpq format connection string,
+ e.g. "hostaddr=127.0.0.1 port=5432 dbname=mydb user=postgres password=mypasswd"
+
+ if only one argument is given, the connection is unnamed; only one unnamed
+ connection can exist at a time
+
+Outputs
+
+ Returns status = "OK"
+
+Notes
+
+ With dblink_connect_u, a non-superuser may connect to any database server
+ using any authentication method. If the authentication method specified
+ for a particular user does not require a password, impersonation and
+ therefore escalation of privileges may occur. For this reason,
+ dblink_connect_u is initially installed with all privileges revoked from
+ public. Privilege to these functions should be granted with care.
+
+Example usage
+
+
==================================================================
Name
projects / users / c2main / postgres.git / commitdiff