Improve error reporting for SSL connection failures. Remove redundant

free operations in client_cert_cb --- openssl will also attempt to free
these structures, resulting in core dumps.

Author: tglsfdc

src/backend/libpq/be-secure.c

@@ -11,7 +11,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/libpq/be-secure.c,v 1.53 2004/11/17 04:05:42 neilc Exp $
+ *	  $PostgreSQL: pgsql/src/backend/libpq/be-secure.c,v 1.54 2004/11/20 00:18:13 tgl Exp $
  *
  *	  Since the server static private key ($DataDir/server.key)
  *	  will normally be stored unencrypted so that the database
@@ -727,37 +727,6 @@ initialize_SSL(void)
 	return 0;
 }
 
-#ifdef WIN32
-/*
- *	Win32 socket code uses nonblocking sockets. We ned to deal with that
- *	by waiting on the socket if the SSL accept operation didn't complete
- *	right away.
- */
-static int pgwin32_SSL_accept(SSL *ssl)
-{
-	int r;
-
-	while (1)
-	{
-		int rc;
-		int waitfor;
-
-		r = SSL_accept(ssl);
-		if (r == 1)
-			return 1;
-
-		rc = SSL_get_error(ssl, r);
-		if (rc != SSL_ERROR_WANT_READ && rc != SSL_ERROR_WANT_WRITE)
-			return r;
-
-		waitfor = (rc == SSL_ERROR_WANT_READ)?FD_READ|FD_CLOSE|FD_ACCEPT:FD_WRITE|FD_CLOSE;
-		if (pgwin32_waitforsinglesocket(SSL_get_fd(ssl), waitfor) == 0)
-			return -1;
-	}
-}
-#define SSL_accept(ssl) pgwin32_SSL_accept(ssl)
-#endif
-
 /*
  *	Destroy global SSL context.
  */
@@ -777,7 +746,9 @@ destroy_SSL(void)
 static int
 open_server_SSL(Port *port)
 {
-	int r;
+	int			r;
+	int			err;
+
 	Assert(!port->ssl);
 	Assert(!port->peer);
 
@@ -799,12 +770,50 @@ open_server_SSL(Port *port)
 		close_SSL(port);
 		return -1;
 	}
-	if ((r=SSL_accept(port->ssl)) <= 0)
+
+aloop:
+	r = SSL_accept(port->ssl);
+	if (r <= 0)
 	{
-		ereport(COMMERROR,
-				(errcode(ERRCODE_PROTOCOL_VIOLATION),
-				 errmsg("could not accept SSL connection: %i",
-						SSL_get_error(port->ssl,r))));
+		err = SSL_get_error(port->ssl, r);
+		switch (err)
+		{
+			case SSL_ERROR_WANT_READ:
+			case SSL_ERROR_WANT_WRITE:
+#ifdef WIN32
+				pgwin32_waitforsinglesocket(SSL_get_fd(port->ssl),
+					(err==SSL_ERROR_WANT_READ) ?
+						FD_READ|FD_CLOSE|FD_ACCEPT : FD_WRITE|FD_CLOSE);
+#endif
+				goto aloop;
+			case SSL_ERROR_SYSCALL:
+				if (r < 0)
+					ereport(COMMERROR,
+							(errcode_for_socket_access(),
+							 errmsg("could not accept SSL connection: %m")));
+				else
+					ereport(COMMERROR,
+							(errcode(ERRCODE_PROTOCOL_VIOLATION),
+							 errmsg("could not accept SSL connection: EOF detected")));
+				break;
+			case SSL_ERROR_SSL:
+				ereport(COMMERROR,
+						(errcode(ERRCODE_PROTOCOL_VIOLATION),
+						 errmsg("could not accept SSL connection: %s",
+								SSLerrmessage())));
+				break;
+			case SSL_ERROR_ZERO_RETURN:
+				ereport(COMMERROR,
+						(errcode(ERRCODE_PROTOCOL_VIOLATION),
+						 errmsg("could not accept SSL connection: EOF detected")));
+				break;
+			default:
+				ereport(COMMERROR,
+						(errcode(ERRCODE_PROTOCOL_VIOLATION),
+						 errmsg("unrecognized SSL error code: %d",
+								err)));
+				break;
+		}
 		close_SSL(port);
 		return -1;
 	}

src/interfaces/libpq/fe-secure.c

@@ -11,7 +11,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/interfaces/libpq/fe-secure.c,v 1.55 2004/10/16 03:26:43 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/interfaces/libpq/fe-secure.c,v 1.56 2004/11/20 00:18:18 tgl Exp $
  *
  * NOTES
  *	  [ Most of these notes are wrong/obsolete, but perhaps not all ]
@@ -267,6 +267,11 @@ pqsecure_open_client(PGconn *conn)
 			close_SSL(conn);
 			return PGRES_POLLING_FAILED;
 		}
+		/*
+		 * Initialize errorMessage to empty.  This allows open_client_SSL()
+		 * to detect whether client_cert_cb() has stored a message.
+		 */
+		resetPQExpBuffer(&conn->errorMessage);
 	}
 	/* Begin or continue the actual handshake */
 	return open_client_SSL(conn);
@@ -797,7 +802,6 @@ client_cert_cb(SSL *ssl, X509 **x509, EVP_PKEY **pkey)
 		printfPQExpBuffer(&conn->errorMessage,
 		libpq_gettext("certificate present, but not private key file \"%s\"\n"),
 						  fnbuf);
-		X509_free(*x509);
 		return 0;
 	}
 	if (!S_ISREG(buf.st_mode) || (buf.st_mode & 0077) ||
@@ -806,23 +810,20 @@ client_cert_cb(SSL *ssl, X509 **x509, EVP_PKEY **pkey)
 		printfPQExpBuffer(&conn->errorMessage,
 		libpq_gettext("private key file \"%s\" has wrong permissions\n"),
 						  fnbuf);
-		X509_free(*x509);
 		return 0;
 	}
 	if ((fp = fopen(fnbuf, "r")) == NULL)
 	{
 		printfPQExpBuffer(&conn->errorMessage,
 			 libpq_gettext("could not open private key file \"%s\": %s\n"),
 						  fnbuf, pqStrerror(errno, sebuf, sizeof(sebuf)));
-		X509_free(*x509);
 		return 0;
 	}
 	if (fstat(fileno(fp), &buf2) == -1 ||
 		buf.st_dev != buf2.st_dev || buf.st_ino != buf2.st_ino)
 	{
 		printfPQExpBuffer(&conn->errorMessage,
 						  libpq_gettext("private key file \"%s\" changed during execution\n"), fnbuf);
-		X509_free(*x509);
 		return 0;
 	}
 	if (PEM_read_PrivateKey(fp, pkey, cb, NULL) == NULL)
@@ -833,7 +834,6 @@ client_cert_cb(SSL *ssl, X509 **x509, EVP_PKEY **pkey)
 				  libpq_gettext("could not read private key file \"%s\": %s\n"),
 						  fnbuf, err);
 		SSLerrfree(err);
-		X509_free(*x509);
 		fclose(fp);
 		return 0;
 	}
@@ -848,8 +848,6 @@ client_cert_cb(SSL *ssl, X509 **x509, EVP_PKEY **pkey)
 			libpq_gettext("certificate does not match private key file \"%s\": %s\n"),
 						  fnbuf, err);
 		SSLerrfree(err);
-		X509_free(*x509);
-		EVP_PKEY_free(*pkey);
 		return 0;
 	}
 
@@ -1045,11 +1043,23 @@ open_client_SSL(PGconn *conn)
 				}
 			case SSL_ERROR_SSL:
 				{
-					char	   *err = SSLerrmessage();
+					/*
+					 * If there are problems with the local certificate files,
+					 * these will be detected by client_cert_cb() which is
+					 * called from SSL_connect().  We want to return that
+					 * error message and not the rather unhelpful error that
+					 * OpenSSL itself returns.  So check to see if an error
+					 * message was already stored.
+					 */
+					if (conn->errorMessage.len == 0)
+					{
+						char	   *err = SSLerrmessage();
 
-					printfPQExpBuffer(&conn->errorMessage,
-								  libpq_gettext("SSL error: %s\n"), err);
-					SSLerrfree(err);
+						printfPQExpBuffer(&conn->errorMessage,
+										  libpq_gettext("SSL error: %s\n"),
+										  err);
+						SSLerrfree(err);
+					}
 					close_SSL(conn);
 					return PGRES_POLLING_FAILED;
 				}