Re: passwords in pg_shadow (duplicate).

OK, I have applied the following patch to CVS and 7.3.  The fix will be
in 7.3.1 to allow 'password' even if pg_shadow contains MD5 passwords.

---------------------------------------------------------------------------

Hiroshi Inoue wrote:
> Bruce Momjian wrote:
> >
> > Good catch.  Seems like a bug.  I assumed we still want to support
> > 'password' even though pg_shadow contains MD5 encrypted passwords.  Is
> > that correct?  (We can't support crypt in those cases.)
> >
> > The following patch fixes this.  I need to review it later, but we could
> > apply to 7.3.1.  I assume there are still some interfaces that don't
> > support md5 or crypt and we will need this patch to continue supporting
> > them, though I am sure there are some out there that want 'password' to
> > go away.
>
> Honestly I don't understand your intention.
> For example, if some one would like to use
> crypt authentication what should he do ?
> Certainly he can store a plain password using
> 'with unencrypted password ....'. But pg_dump
> would dump it as 'with password ....' and as
> a result the password would be restored as MD5
> encrypted password by default.
>
> regards,
> Hiroshi Inoue
>     http://w2422.nsk.ne.jp/~inoue/
>
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>

--
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 359-1001
  +  If your life is a hard drive,     |  13 Roberts Road
  +  Christ can be your backup.        |  Newtown Square, Pennsylvania 19073
Index: src/backend/libpq/crypt.c
===================================================================
RCS file: /cvsroot/pgsql-server/src/backend/libpq/crypt.c,v
retrieving revision 1.49
diff -c -c -r1.49 crypt.c
*** src/backend/libpq/crypt.c    4 Sep 2002 20:31:19 -0000    1.49
--- src/backend/libpq/crypt.c    5 Dec 2002 18:03:53 -0000
***************
*** 29,35 ****


  int
! md5_crypt_verify(const Port *port, const char *user, const char *pgpass)
  {
      char       *passwd = NULL,
                 *valuntil = NULL,
--- 29,35 ----


  int
! md5_crypt_verify(const Port *port, const char *user, char *pgpass)
  {
      char       *passwd = NULL,
                 *valuntil = NULL,
***************
*** 37,42 ****
--- 37,43 ----
      int            retval = STATUS_ERROR;
      List      **line;
      List       *token;
+     char       *crypt_pgpass = pgpass;

      if ((line = get_user_line(user)) == NULL)
          return STATUS_ERROR;
***************
*** 54,64 ****
      if (passwd == NULL || *passwd == '\0')
          return STATUS_ERROR;

!     /* If they encrypt their password, force MD5 */
!     if (isMD5(passwd) && port->auth_method != uaMD5)
      {
          elog(LOG, "Password is stored MD5 encrypted.  "
!              "'password' and 'crypt' auth methods cannot be used.");
          return STATUS_ERROR;
      }

--- 55,65 ----
      if (passwd == NULL || *passwd == '\0')
          return STATUS_ERROR;

!     /* We can't do crypt with pg_shadow MD5 passwords */
!     if (isMD5(passwd) && port->auth_method == uaCrypt)
      {
          elog(LOG, "Password is stored MD5 encrypted.  "
!              "'crypt' auth method cannot be used.");
          return STATUS_ERROR;
      }

***************
*** 72,77 ****
--- 73,79 ----
              crypt_pwd = palloc(MD5_PASSWD_LEN + 1);
              if (isMD5(passwd))
              {
+                 /* pg_shadow already encrypted, only do salt */
                  if (!EncryptMD5(passwd + strlen("md5"),
                                  (char *) port->md5Salt,
                                  sizeof(port->md5Salt), crypt_pwd))
***************
*** 82,87 ****
--- 84,90 ----
              }
              else
              {
+                 /* pg_shadow plain, double-encrypt */
                  char       *crypt_pwd2 = palloc(MD5_PASSWD_LEN + 1);

                  if (!EncryptMD5(passwd, port->user, strlen(port->user),
***************
*** 110,120 ****
                  break;
              }
          default:
              crypt_pwd = passwd;
              break;
      }

!     if (strcmp(pgpass, crypt_pwd) == 0)
      {
          /*
           * Password OK, now check to be sure we are not past valuntil
--- 113,134 ----
                  break;
              }
          default:
+             if (isMD5(passwd))
+             {
+                 /* Encrypt user-supplied password to match MD5 in pg_shadow */
+                 crypt_pgpass = palloc(MD5_PASSWD_LEN + 1);
+                 if (!EncryptMD5(pgpass, port->user, strlen(port->user),
+                                 crypt_pgpass))
+                 {
+                     pfree(crypt_pgpass);
+                     return STATUS_ERROR;
+                 }
+             }
              crypt_pwd = passwd;
              break;
      }

!     if (strcmp(crypt_pgpass, crypt_pwd) == 0)
      {
          /*
           * Password OK, now check to be sure we are not past valuntil
***************
*** 136,141 ****
--- 150,157 ----

      if (port->auth_method == uaMD5)
          pfree(crypt_pwd);
+     if (crypt_pgpass != pgpass)
+         pfree(crypt_pgpass);

      return retval;
  }
Index: src/include/libpq/crypt.h
===================================================================
RCS file: /cvsroot/pgsql-server/src/include/libpq/crypt.h,v
retrieving revision 1.22
diff -c -c -r1.22 crypt.h
*** src/include/libpq/crypt.h    4 Sep 2002 20:31:42 -0000    1.22
--- src/include/libpq/crypt.h    5 Dec 2002 18:03:54 -0000
***************
*** 23,29 ****


  extern int md5_crypt_verify(const Port *port, const char *user,
!                  const char *pgpass);
  extern bool md5_hash(const void *buff, size_t len, char *hexsum);
  extern bool CheckMD5Pwd(char *passwd, char *storedpwd, char *seed);

--- 23,29 ----


  extern int md5_crypt_verify(const Port *port, const char *user,
!                 char *pgpass);
  extern bool md5_hash(const void *buff, size_t len, char *hexsum);
  extern bool CheckMD5Pwd(char *passwd, char *storedpwd, char *seed);