Arrange for the authentication request type to be preserved in

PGconn. Invent a new libpq connection-status function,
PQconnectionUsedPassword() that returns true if the server
demanded a password during authentication, false otherwise.
This may be useful to clients in general, but is immediately
useful to help plug a privilege escalation path in dblink.
Per list discussion and design proposed by Tom Lane.

diff --git a/doc/src/sgml/libpq.sgml b/doc/src/sgml/libpq.sgml
index 1a4118174e819ea404b543cbdbca19879251e80e..bbaade6944fb7e7c5d48958aff9cd0ef69f4a4c0 100644 (file)
--- a/doc/src/sgml/libpq.sgml
+++ b/doc/src/sgml/libpq.sgml
@@ -1,4 +1,4 @@
-<!-- $PostgreSQL: pgsql/doc/src/sgml/libpq.sgml,v 1.235 2007/03/30 03:19:02 momjian Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/libpq.sgml,v 1.236 2007/07/08 17:11:50 joe Exp $ -->
 
  <chapter id="libpq">
   <title><application>libpq</application> - C Library</title>
@@ -1059,6 +1059,20 @@ SSL *PQgetssl(const PGconn *conn);
      </listitem>
     </varlistentry>
 
+    <varlistentry>
+     <term><function>PQconnectionUsedPassword</function><indexterm><primary>PQconnectionUsedPassword</></></term>
+     <listitem>
+      <para>
+       Returns true (1) if the connection authentication method
+       required a password to be supplied. Returns false (0)
+       otherwise.
+       <synopsis>
+       bool PQconnectionUsedPassword(const PGconn *conn);
+       </synopsis>
+      </para>
+     </listitem>
+    </varlistentry>
+
 </variablelist>
 </para>
 

diff --git a/src/include/libpq/pqcomm.h b/src/include/libpq/pqcomm.h
index 140d6ba0c5d1a607e9c4c680784a2da461c7e170..047940b7adf3622ec22827eb9073d7c3ba301c6c 100644 (file)
--- a/src/include/libpq/pqcomm.h
+++ b/src/include/libpq/pqcomm.h
@@ -9,7 +9,7 @@
  * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/libpq/pqcomm.h,v 1.102 2007/01/05 22:19:55 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/libpq/pqcomm.h,v 1.103 2007/07/08 17:11:51 joe Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -156,6 +156,7 @@ extern bool Db_user_namespace;
 #define AUTH_REQ_CRYPT     4   /* crypt password */
 #define AUTH_REQ_MD5       5   /* md5 password */
 #define AUTH_REQ_SCM_CREDS 6   /* transfer SCM credentials */
+#define AUTH_REQ_UNK       7   /* User has not yet attempted to authenticate */
 
 typedef uint32 AuthRequest;
 

diff --git a/src/interfaces/libpq/exports.txt b/src/interfaces/libpq/exports.txt
index 667301aeac9555cec6ee08d8a3c4e8c380b817e8..a0ead41ace52b5c54f658226b06e87b718fe119a 100644 (file)
--- a/src/interfaces/libpq/exports.txt
+++ b/src/interfaces/libpq/exports.txt
@@ -1,4 +1,4 @@
-# $PostgreSQL: pgsql/src/interfaces/libpq/exports.txt,v 1.15 2007/03/03 19:52:46 momjian Exp $
+# $PostgreSQL: pgsql/src/interfaces/libpq/exports.txt,v 1.16 2007/07/08 17:11:51 joe Exp $
 # Functions to be exported by libpq DLLs
 PQconnectdb               1
 PQsetdbLogin              2
@@ -137,3 +137,4 @@ PQdescribePortal          134
 PQsendDescribePrepared    135
 PQsendDescribePortal      136
 lo_truncate               137
+PQconnectionUsedPassword  138

diff --git a/src/interfaces/libpq/fe-connect.c b/src/interfaces/libpq/fe-connect.c
index 13c407d1cc18e86982c8536611870ee9851b7463..a19b444c593c9555b7502d1e478f2d9f520cbf5e 100644 (file)
--- a/src/interfaces/libpq/fe-connect.c
+++ b/src/interfaces/libpq/fe-connect.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *   $PostgreSQL: pgsql/src/interfaces/libpq/fe-connect.c,v 1.345 2007/03/08 19:27:28 mha Exp $
+ *   $PostgreSQL: pgsql/src/interfaces/libpq/fe-connect.c,v 1.346 2007/07/08 17:11:51 joe Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1641,6 +1641,10 @@ keep_going:                      /* We will come back to here until there is
                    return PGRES_POLLING_READING;
                }
 
+               /* save the authentication request type */
+               if (conn->areq == AUTH_REQ_UNK)
+                   conn->areq = areq;
+
                /* Get the password salt if there is one. */
                if (areq == AUTH_REQ_MD5)
                {
@@ -1873,6 +1877,7 @@ makeEmptyPGconn(void)
    conn->std_strings = false;  /* unless server says differently */
    conn->verbosity = PQERRORS_DEFAULT;
    conn->sock = -1;
+   conn->areq = AUTH_REQ_UNK;
 #ifdef USE_SSL
    conn->allow_ssl_try = true;
    conn->wait_ssl_try = false;
@@ -3441,6 +3446,17 @@ PQsetClientEncoding(PGconn *conn, const char *encoding)
    return status;
 }
 
+bool
+PQconnectionUsedPassword(const PGconn *conn)
+{
+   if (conn->areq == AUTH_REQ_MD5 ||
+       conn->areq == AUTH_REQ_CRYPT ||
+       conn->areq == AUTH_REQ_PASSWORD)
+       return true;
+   else
+       return false;
+}
+
 PGVerbosity
 PQsetErrorVerbosity(PGconn *conn, PGVerbosity verbosity)
 {

diff --git a/src/interfaces/libpq/libpq-fe.h b/src/interfaces/libpq/libpq-fe.h
index f89d3e1a4c88b6cd3f62f2cd36b840d7e57cd55f..efda5a0049e5cd401fdccd743fee59764fdf378e 100644 (file)
--- a/src/interfaces/libpq/libpq-fe.h
+++ b/src/interfaces/libpq/libpq-fe.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/interfaces/libpq/libpq-fe.h,v 1.136 2007/03/03 19:52:46 momjian Exp $
+ * $PostgreSQL: pgsql/src/interfaces/libpq/libpq-fe.h,v 1.137 2007/07/08 17:11:51 joe Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -23,10 +23,11 @@ extern      "C"
 #include <stdio.h>
 
 /*
- * postgres_ext.h defines the backend's externally visible types,
+ * defines the backend's externally visible types,
  * such as Oid.
  */
 #include "postgres_ext.h"
+#include "postgres_fe.h"
 
 /* Application-visible enum types */
 
@@ -265,6 +266,7 @@ extern int  PQsocket(const PGconn *conn);
 extern int PQbackendPID(const PGconn *conn);
 extern int PQclientEncoding(const PGconn *conn);
 extern int PQsetClientEncoding(PGconn *conn, const char *encoding);
+extern bool    PQconnectionUsedPassword(const PGconn *conn);
 
 /* Get the OpenSSL structure associated with a connection. Returns NULL for
  * unencrypted connections or if any other TLS library is in use. */

diff --git a/src/interfaces/libpq/libpq-int.h b/src/interfaces/libpq/libpq-int.h
index 676d2db4d1aa64bd12808787ed3d73965d7cfd54..12a9bd83a69ddc6ea15579646612a19d52403519 100644 (file)
--- a/src/interfaces/libpq/libpq-int.h
+++ b/src/interfaces/libpq/libpq-int.h
@@ -12,7 +12,7 @@
  * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/interfaces/libpq/libpq-int.h,v 1.119 2007/03/03 19:52:47 momjian Exp $
+ * $PostgreSQL: pgsql/src/interfaces/libpq/libpq-int.h,v 1.120 2007/07/08 17:11:51 joe Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -299,6 +299,7 @@ struct pg_conn
    SockAddr    raddr;          /* Remote address */
    ProtocolVersion pversion;   /* FE/BE protocol version in use */
    int         sversion;       /* server version, e.g. 70401 for 7.4.1 */
+   AuthRequest areq;           /* server demanded password during auth */
 
    /* Transient state needed while establishing connection */
    struct addrinfo *addrlist;  /* list of possible backend addresses */