database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-07-03 20:02:46 +03:00
Code Activity

UPDATED PATCH:

Browse Source 
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
This commit is contained in:
Bruce Momjian
2002-06-14 04:23:17 +00:00
parent eb43af3210
commit 19570420f5
9 changed files with 996 additions and 211 deletions
Download Patch File Download Diff File Expand all files Collapse all files

42
src/interfaces/libpq/fe-misc.c
View File

@ -25,7 +25,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/interfaces/libpq/fe-misc.c,v 1.72 2002/06/14 04:09:37 momjian Exp $
* $Header: /cvsroot/pgsql/src/interfaces/libpq/fe-misc.c,v 1.73 2002/06/14 04:23:17 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@ -55,6 +55,9 @@
#include "mb/pg_wchar.h"
#endif
extern void secure_close(PGconn *);
extern ssize_t secure_read(PGconn *, void *, size_t);
extern ssize_t secure_write(PGconn *, const void *, size_t);
#define DONOTICE(conn,message) \
((*(conn)->noticeHook) ((conn)->noticeArg, (message)))
@ -477,14 +480,8 @@ pqReadData(PGconn *conn)
/* OK, try to read some data */
retry3:
#ifdef USE_SSL
if (conn->ssl)
nread = SSL_read(conn->ssl, conn->inBuffer + conn->inEnd,
conn->inBufSize - conn->inEnd);
else
#endif
nread = recv(conn->sock, conn->inBuffer + conn->inEnd,
conn->inBufSize - conn->inEnd, 0);
nread = secure_read(conn, conn->inBuffer + conn->inEnd,
conn->inBufSize - conn->inEnd);
if (nread < 0)
{
if (SOCK_ERRNO == EINTR)
@ -563,14 +560,8 @@ retry3:
* arrived.
*/
retry4:
#ifdef USE_SSL
if (conn->ssl)
nread = SSL_read(conn->ssl, conn->inBuffer + conn->inEnd,
conn->inBufSize - conn->inEnd);
else
#endif
nread = recv(conn->sock, conn->inBuffer + conn->inEnd,
conn->inBufSize - conn->inEnd, 0);
nread = secure_read(conn, conn->inBuffer + conn->inEnd,
conn->inBufSize - conn->inEnd);
if (nread < 0)
{
if (SOCK_ERRNO == EINTR)
@ -611,6 +602,7 @@ definitelyFailed:
"\tThis probably means the server terminated abnormally\n"
"\tbefore or while processing the request.\n"));
conn->status = CONNECTION_BAD; /* No more connection to backend */
secure_close(conn);
#ifdef WIN32
closesocket(conn->sock);
#else
@ -650,23 +642,9 @@ pqSendSome(PGconn *conn)
/* while there's still data to send */
while (len > 0)
{
/* Prevent being SIGPIPEd if backend has closed the connection. */
#ifndef WIN32
pqsigfunc oldsighandler = pqsignal(SIGPIPE, SIG_IGN);
#endif
int sent;
#ifdef USE_SSL
if (conn->ssl)
sent = SSL_write(conn->ssl, ptr, len);
else
#endif
sent = send(conn->sock, ptr, len, 0);
#ifndef WIN32
pqsignal(SIGPIPE, oldsighandler);
#endif
sent = secure_write(conn, ptr, len);
if (sent < 0)
{