UPDATED PATCH:

Attached are a revised set of SSL patches.  Many of these patches
are motivated by security concerns, it's not just bug fixes.  The key
differences (from stock 7.2.1) are:

*) almost all code that directly uses the OpenSSL library is in two
   new files,

     src/interfaces/libpq/fe-ssl.c
     src/backend/postmaster/be-ssl.c

   in the long run, it would be nice to merge these two files.

*) the legacy code to read and write network data have been
   encapsulated into read_SSL() and write_SSL().  These functions
   should probably be renamed - they handle both SSL and non-SSL
   cases.

   the remaining code should eliminate the problems identified
   earlier, albeit not very cleanly.

*) both front- and back-ends will send a SSL shutdown via the
   new close_SSL() function.  This is necessary for sessions to
   work properly.

   (Sessions are not yet fully supported, but by cleanly closing
   the SSL connection instead of just sending a TCP FIN packet
   other SSL tools will be much happier.)

*) The client certificate and key are now expected in a subdirectory
   of the user's home directory.  Specifically,

	- the directory .postgresql must be owned by the user, and
	  allow no access by 'group' or 'other.'

	- the file .postgresql/postgresql.crt must be a regular file
	  owned by the user.

	- the file .postgresql/postgresql.key must be a regular file
	  owned by the user, and allow no access by 'group' or 'other'.

   At the current time encrypted private keys are not supported.
   There should also be a way to support multiple client certs/keys.

*) the front-end performs minimal validation of the back-end cert.
   Self-signed certs are permitted, but the common name *must*
   match the hostname used by the front-end.  (The cert itself
   should always use a fully qualified domain name (FDQN) in its
   common name field.)

   This means that

	  psql -h eris db

   will fail, but

	  psql -h eris.example.com db

   will succeed.  At the current time this must be an exact match;
   future patches may support any FQDN that resolves to the address
   returned by getpeername(2).

   Another common "problem" is expiring certs.  For now, it may be
   a good idea to use a very-long-lived self-signed cert.

   As a compile-time option, the front-end can specify a file
   containing valid root certificates, but it is not yet required.

*) the back-end performs minimal validation of the client cert.
   It allows self-signed certs.  It checks for expiration.  It
   supports a compile-time option specifying a file containing
   valid root certificates.

*) both front- and back-ends default to TLSv1, not SSLv3/SSLv2.

*) both front- and back-ends support DSA keys.  DSA keys are
   moderately more expensive on startup, but many people consider
   them preferable than RSA keys.  (E.g., SSH2 prefers DSA keys.)

*) if /dev/urandom exists, both client and server will read 16k
   of randomization data from it.

*) the server can read empheral DH parameters from the files

     $DataDir/dh512.pem
     $DataDir/dh1024.pem
     $DataDir/dh2048.pem
     $DataDir/dh4096.pem

   if none are provided, the server will default to hardcoded
   parameter files provided by the OpenSSL project.

Remaining tasks:

*) the select() clauses need to be revisited - the SSL abstraction
   layer may need to absorb more of the current code to avoid rare
   deadlock conditions.  This also touches on a true solution to
   the pg_eof() problem.

*) the SIGPIPE signal handler may need to be revisited.

*) support encrypted private keys.

*) sessions are not yet fully supported.  (SSL sessions can span
   multiple "connections," and allow the client and server to avoid
   costly renegotiations.)

*) makecert - a script that creates back-end certs.

*) pgkeygen - a tool that creates front-end certs.

*) the whole protocol issue, SASL, etc.

 *) certs are fully validated - valid root certs must be available.
    This is a hassle, but it means that you *can* trust the identity
    of the server.

 *) the client library can handle hardcoded root certificates, to
    avoid the need to copy these files.

 *) host name of server cert must resolve to IP address, or be a
    recognized alias.  This is more liberal than the previous
    iteration.

 *) the number of bytes transferred is tracked, and the session
    key is periodically renegotiated.

 *) basic cert generation scripts (mkcert.sh, pgkeygen.sh).  The
    configuration files have reasonable defaults for each type
    of use.

Bear Giles

1 files changed, 11 insertions, 67 deletions

diff --git a/src/interfaces/libpq/fe-connect.c b/src/interfaces/libpq/fe-connect.c
index 02164778b76..414fff329e5 100644
--- a/src/interfaces/libpq/fe-connect.c
+++ b/src/interfaces/libpq/fe-connect.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/interfaces/libpq/fe-connect.c,v 1.185 2002/06/14 04:09:37 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/interfaces/libpq/fe-connect.c,v 1.186 2002/06/14 04:23:17 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -61,9 +61,12 @@ inet_aton(const char *cp, struct in_addr * inp)
 }
 #endif
 
-
 #ifdef USE_SSL
-static SSL_CTX *SSL_context = NULL;
+extern int secure_initialize(PGconn *);
+extern void secure_destroy(void);
+extern int secure_open_client(PGconn *);
+extern void secure_close(PGconn *);
+extern SSL * PQgetssl(PGconn *);
 #endif
 
 #define NOTIFYLIST_INITIAL_SIZE 10
@@ -186,10 +189,6 @@ static char *conninfo_getval(PQconninfoOption *connOptions,
 static void defaultNoticeProcessor(void *arg, const char *message);
 static int parseServiceInfo(PQconninfoOption *options,
 				 PQExpBuffer errorMessage);
-#ifdef USE_SSL
-static const char *SSLerrmessage(void);
-#endif
-
 
 /*
  *		Connecting to a Database
@@ -969,26 +968,8 @@ retry2:
 		}
 		if (SSLok == 'S')
 		{
-			if (!SSL_context)
+			if (secure_initialize(conn) == -1 || secure_open_client(conn) == -1)
 			{
-				SSL_load_error_strings();
-				SSL_library_init();
-				SSL_context = SSL_CTX_new(SSLv23_method());
-				if (!SSL_context)
-				{
-					printfPQExpBuffer(&conn->errorMessage,
-					 libpq_gettext("could not create SSL context: %s\n"),
-									  SSLerrmessage());
-					goto connect_errReturn;
-				}
-			}
-			if (!(conn->ssl = SSL_new(SSL_context)) ||
-				!SSL_set_fd(conn->ssl, conn->sock) ||
-				SSL_connect(conn->ssl) <= 0)
-			{
-				printfPQExpBuffer(&conn->errorMessage,
-				libpq_gettext("could not establish SSL connection: %s\n"),
-								  SSLerrmessage());
 				goto connect_errReturn;
 			}
 			/* SSL connection finished. Continue to send startup packet */
@@ -998,6 +979,7 @@ retry2:
 			/* Received error - probably protocol mismatch */
 			if (conn->Pfdebug)
 				fprintf(conn->Pfdebug, "Postmaster reports error, attempting fallback to pre-7.0.\n");
+			secure_close(conn);
 #ifdef WIN32
 			closesocket(conn->sock);
 #else
@@ -1039,6 +1021,7 @@ retry2:
 connect_errReturn:
 	if (conn->sock >= 0)
 	{
+		secure_close(conn);
 #ifdef WIN32
 		closesocket(conn->sock);
 #else
@@ -1914,8 +1897,7 @@ freePGconn(PGconn *conn)
 		return;
 	pqClearAsyncResult(conn);	/* deallocate result and curTuple */
 #ifdef USE_SSL
-	if (conn->ssl)
-		SSL_free(conn->ssl);
+	secure_close(conn);
 #endif
 	if (conn->sock >= 0)
 	{
@@ -1992,6 +1974,7 @@ closePGconn(PGconn *conn)
 	 */
 	if (conn->sock >= 0)
 	{
+		secure_close(conn);
 #ifdef WIN32
 		closesocket(conn->sock);
 #else
@@ -2641,35 +2624,6 @@ PQconninfoFree(PQconninfoOption *connOptions)
 }
 
 
-#ifdef USE_SSL
-
-/*
- * Obtain reason string for last SSL error
- *
- * Some caution is needed here since ERR_reason_error_string will
- * return NULL if it doesn't recognize the error code.  We don't
- * want to return NULL ever.
- */
-static const char *
-SSLerrmessage(void)
-{
-	unsigned long	errcode;
-	const char	   *errreason;
-	static char		errbuf[32];
-
-	errcode = ERR_get_error();
-	if (errcode == 0)
-		return "No SSL error reported";
-	errreason = ERR_reason_error_string(errcode);
-	if (errreason != NULL)
-		return errreason;
-	snprintf(errbuf, sizeof(errbuf), "SSL error code %lu", errcode);
-	return errbuf;
-}
-
-#endif /* USE_SSL */
-
-
 /* =========== accessor functions for PGconn ========= */
 char *
 PQdb(const PGconn *conn)
@@ -2814,16 +2768,6 @@ PQsetClientEncoding(PGconn *conn, const char *encoding)
 }
 #endif
 
-#ifdef USE_SSL
-SSL *
-PQgetssl(PGconn *conn)
-{
-	if (!conn)
-		return NULL;
-	return conn->ssl;
-}
-#endif
-
 void
 PQtrace(PGconn *conn, FILE *debug_port)
 {