Re: Warning about invalid .pgpass passwords

Bruce Momjian wrote:
> Tom Lane wrote:
> > Bruce Momjian <bruce@momjian.us> writes:
> > > Tom Lane wrote:
> > >> I'm inclined to think that maybe we should make the server return a
> > >> distinct SQLSTATE for "bad password", and have libpq check for that
> > >> rather than just assuming that the failure must be bad password.
> >
> > > Modifying the backend to issue this hint seems like overkill, unless we
> > > have some other use for it.
> >
> > I wouldn't suggest it if I thought it were only helpful for this
> > particular message.  It seems to me that we've spent a lot of time
> > kluging around the lack of certainty about whether a connection failure
> > is a password issue.  Admittedly a lot of that was between libpq and its
> > client, but the state of affairs on the wire isn't great either.
>
> Yes, I have seen that myself in psql.
>
> > I'm not convinced we have to do it that way, but now is definitely
> > the time to think about it before we implement yet another
> > sort-of-good-enough kluge.  Which is what this is.
>
> True.  Should we just hold this all for 9.1 or should I code it and
> let's look at the size of the patch?

With no one replying, I decide to code up a patch that adds a new
SQLSTATE (28001) to report invalid/missing passwords.  With this code,
the warning will only appear when connecting to 9.0 servers.  The output
still looks the same, but will only appear for a password failure:

    $ sql -h localhost test
    psql: FATAL:  password authentication failed for user "postgres"
    password retrieved from .pgpass

--
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

  PG East:  http://www.enterprisedb.com/community/nav-pg-east-2010.do
Index: doc/src/sgml/errcodes.sgml
===================================================================
RCS file: /cvsroot/pgsql/doc/src/sgml/errcodes.sgml,v
retrieving revision 1.28
diff -c -c -r1.28 errcodes.sgml
*** doc/src/sgml/errcodes.sgml    7 Dec 2009 05:22:21 -0000    1.28
--- doc/src/sgml/errcodes.sgml    11 Mar 2010 21:07:09 -0000
***************
*** 761,766 ****
--- 761,772 ----
  <entry>invalid_authorization_specification</entry>
  </row>

+ <row>
+ <entry><literal>28001</literal></entry>
+ <entry>INVALID PASSWORD SPECIFICATION</entry>
+ <entry>invalid_password_specification</entry>
+ </row>
+

  <row>
  <entry spanname="span13"><emphasis role="bold">Class 2B — Dependent Privilege Descriptors Still
Exist</></entry>
Index: src/backend/libpq/auth.c
===================================================================
RCS file: /cvsroot/pgsql/src/backend/libpq/auth.c,v
retrieving revision 1.195
diff -c -c -r1.195 auth.c
*** src/backend/libpq/auth.c    26 Feb 2010 02:00:42 -0000    1.195
--- src/backend/libpq/auth.c    11 Mar 2010 21:07:16 -0000
***************
*** 232,238 ****
  auth_failed(Port *port, int status)
  {
      const char *errstr;
!
      /*
       * If we failed due to EOF from client, just quit; there's no point in
       * trying to send a message to the client, and not much point in logging
--- 232,239 ----
  auth_failed(Port *port, int status)
  {
      const char *errstr;
!     int        errcode_return = ERRCODE_INVALID_AUTHORIZATION_SPECIFICATION;
!
      /*
       * If we failed due to EOF from client, just quit; there's no point in
       * trying to send a message to the client, and not much point in logging
***************
*** 269,274 ****
--- 270,280 ----
          case uaMD5:
          case uaPassword:
              errstr = gettext_noop("password authentication failed for user \"%s\"");
+             /*
+              *    This might require the client to prompt for a password, so we use
+              *    a distinct error code.
+              */
+             errcode_return = ERRCODE_INVALID_PASSWORD_SPECIFICATION;
              break;
          case uaPAM:
              errstr = gettext_noop("PAM authentication failed for user \"%s\"");
***************
*** 285,291 ****
      }

      ereport(FATAL,
!             (errcode(ERRCODE_INVALID_AUTHORIZATION_SPECIFICATION),
               errmsg(errstr, port->user_name)));
      /* doesn't return */
  }
--- 291,297 ----
      }

      ereport(FATAL,
!             (errcode(errcode_return),
               errmsg(errstr, port->user_name)));
      /* doesn't return */
  }
Index: src/include/utils/elog.h
===================================================================
RCS file: /cvsroot/pgsql/src/include/utils/elog.h,v
retrieving revision 1.102
diff -c -c -r1.102 elog.h
*** src/include/utils/elog.h    2 Jan 2010 16:58:10 -0000    1.102
--- src/include/utils/elog.h    11 Mar 2010 21:07:16 -0000
***************
*** 61,66 ****
--- 61,73 ----
      (PGSIXBIT(ch1) + (PGSIXBIT(ch2) << 6) + (PGSIXBIT(ch3) << 12) + \
       (PGSIXBIT(ch4) << 18) + (PGSIXBIT(ch5) << 24))

+ #define SQLSTATE_TO_BASE10(state)    \
+     (((state)        & 0x3F) * 10000 + \
+     (((state) >>  6) & 0x3F) *  1000 + \
+     (((state) >> 12) & 0x3F) *   100 + \
+     (((state) >> 18) & 0x3F) *    10 + \
+     (((state) >> 24) & 0x3F))
+
  /* These macros depend on the fact that '0' becomes a zero in SIXBIT */
  #define ERRCODE_TO_CATEGORY(ec)  ((ec) & ((1 << 12) - 1))
  #define ERRCODE_IS_CATEGORY(ec)  (((ec) & ~((1 << 12) - 1)) == 0)
Index: src/include/utils/errcodes.h
===================================================================
RCS file: /cvsroot/pgsql/src/include/utils/errcodes.h,v
retrieving revision 1.31
diff -c -c -r1.31 errcodes.h
*** src/include/utils/errcodes.h    2 Jan 2010 16:58:10 -0000    1.31
--- src/include/utils/errcodes.h    11 Mar 2010 21:07:16 -0000
***************
*** 194,199 ****
--- 194,200 ----

  /* Class 28 - Invalid Authorization Specification */
  #define ERRCODE_INVALID_AUTHORIZATION_SPECIFICATION MAKE_SQLSTATE('2','8', '0','0','0')
+ #define ERRCODE_INVALID_PASSWORD_SPECIFICATION MAKE_SQLSTATE('2','8', '0','0','1')

  /* Class 2B - Dependent Privilege Descriptors Still Exist */
  #define ERRCODE_DEPENDENT_PRIVILEGE_DESCRIPTORS_STILL_EXIST        MAKE_SQLSTATE('2','B', '0','0','0')
Index: src/interfaces/libpq/fe-connect.c
===================================================================
RCS file: /cvsroot/pgsql/src/interfaces/libpq/fe-connect.c,v
retrieving revision 1.389
diff -c -c -r1.389 fe-connect.c
*** src/interfaces/libpq/fe-connect.c    3 Mar 2010 20:31:09 -0000    1.389
--- src/interfaces/libpq/fe-connect.c    11 Mar 2010 21:07:17 -0000
***************
*** 71,76 ****
--- 71,78 ----

  #include "libpq/ip.h"
  #include "mb/pg_wchar.h"
+ #include "utils/elog.h"
+ #include "utils/errcodes.h"

  #ifndef FD_CLOEXEC
  #define FD_CLOEXEC 1
***************
*** 284,289 ****
--- 286,292 ----
  static char *pwdfMatchesString(char *buf, char *token);
  static char *PasswordFromFile(char *hostname, char *port, char *dbname,
                   char *username);
+ static void dot_pg_pass_warning(PGconn *conn);
  static void default_threadlock(int acquire);


***************
*** 652,657 ****
--- 655,662 ----
                                          conn->dbName, conn->pguser);
          if (conn->pgpass == NULL)
              conn->pgpass = strdup(DefaultPassword);
+         else
+             conn->dot_pgpass_used = true;
      }

      /*
***************
*** 2133,2138 ****
--- 2138,2145 ----

  error_return:

+     dot_pg_pass_warning(conn);
+
      /*
       * We used to close the socket at this point, but that makes it awkward
       * for those above us if they wish to remove this socket from their own
***************
*** 2191,2196 ****
--- 2198,2204 ----
      conn->verbosity = PQERRORS_DEFAULT;
      conn->sock = -1;
      conn->password_needed = false;
+     conn->dot_pgpass_used = false;
  #ifdef USE_SSL
      conn->allow_ssl_try = true;
      conn->wait_ssl_try = false;
***************
*** 4426,4431 ****
--- 4434,4458 ----
  #undef LINELEN
  }

+
+ /*
+  *    If the connection failed, we should mention if
+  *    we got the password from .pgpass in case that
+  *    password is wrong.
+  */
+ static void
+ dot_pg_pass_warning(PGconn *conn)
+ {
+     /* If it was 'invalid authorization', add .pgpass mention */
+     if (conn->dot_pgpass_used && conn->password_needed && conn->result &&
+         /* only works with >= 9.0 servers */
+         atoi(PQresultErrorField(conn->result, PG_DIAG_SQLSTATE)) ==
+             SQLSTATE_TO_BASE10(ERRCODE_INVALID_PASSWORD_SPECIFICATION))
+         appendPQExpBufferStr(&conn->errorMessage,
+             libpq_gettext("password retrieved from .pgpass\n"));
+ }
+
+
  /*
   * Obtain user's home directory, return in given buffer
   *
Index: src/interfaces/libpq/libpq-int.h
===================================================================
RCS file: /cvsroot/pgsql/src/interfaces/libpq/libpq-int.h,v
retrieving revision 1.149
diff -c -c -r1.149 libpq-int.h
*** src/interfaces/libpq/libpq-int.h    26 Feb 2010 02:01:33 -0000    1.149
--- src/interfaces/libpq/libpq-int.h    11 Mar 2010 21:07:19 -0000
***************
*** 343,348 ****
--- 343,349 ----
      ProtocolVersion pversion;    /* FE/BE protocol version in use */
      int            sversion;        /* server version, e.g. 70401 for 7.4.1 */
      bool        password_needed;    /* true if server demanded a password */
+     bool        dot_pgpass_used;    /* true if used .pgpass */
      bool        sigpipe_so;        /* have we masked SIGPIPE via SO_NOSIGPIPE? */
      bool        sigpipe_flag;    /* can we mask SIGPIPE via MSG_NOSIGNAL? */

Index: src/pl/plpgsql/src/plerrcodes.h
===================================================================
RCS file: /cvsroot/pgsql/src/pl/plpgsql/src/plerrcodes.h,v
retrieving revision 1.20
diff -c -c -r1.20 plerrcodes.h
*** src/pl/plpgsql/src/plerrcodes.h    2 Jan 2010 16:58:13 -0000    1.20
--- src/pl/plpgsql/src/plerrcodes.h    11 Mar 2010 21:07:19 -0000
***************
*** 368,373 ****
--- 368,377 ----
  },

  {
+     "invalid_password_specification", ERRCODE_INVALID_PASSWORD_SPECIFICATION
+ },
+
+ {
      "dependent_privilege_descriptors_still_exist", ERRCODE_DEPENDENT_PRIVILEGE_DESCRIPTORS_STILL_EXIST
  },