Rename a libpq NOT_USED SSL function to

verify_peer_name_matches_certificate(), clarify some of the function's
variables and logic, and update a comment.  This should make SSL
improvements easier in the future.
This commit is contained in:
Bruce Momjian 2008-02-16 21:03:30 +00:00
parent e67867b26c
commit d4fa0b4e0a

View File

@ -11,7 +11,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/interfaces/libpq/fe-secure.c,v 1.102 2008/01/29 02:03:39 tgl Exp $
* $PostgreSQL: pgsql/src/interfaces/libpq/fe-secure.c,v 1.103 2008/02/16 21:03:30 momjian Exp $
*
* NOTES
* [ Most of these notes are wrong/obsolete, but perhaps not all ]
@ -143,7 +143,7 @@
#endif
#ifdef NOT_USED
static int verify_peer(PGconn *);
static int verify_peer_name_matches_certificate(PGconn *);
#endif
static int verify_cb(int ok, X509_STORE_CTX *ctx);
static int client_cert_cb(SSL *, X509 **, EVP_PKEY **);
@ -498,18 +498,18 @@ verify_cb(int ok, X509_STORE_CTX *ctx)
* Verify that common name resolves to peer.
*/
static int
verify_peer(PGconn *conn)
verify_peer_name_matches_certificate(PGconn *conn)
{
struct hostent *h = NULL;
struct sockaddr addr;
struct sockaddr_in *sin;
struct hostent *cn_hostentry = NULL;
struct sockaddr server_addr;
struct sockaddr_in *sin (struct sockaddr_in *) &server_addr;
ACCEPT_TYPE_ARG3 len;
char **s;
unsigned long l;
/* get the address on the other side of the socket */
len = sizeof(addr);
if (getpeername(conn->sock, &addr, &len) == -1)
/* Get the address on the other side of the socket. */
len = sizeof(server_addr);
if (getpeername(conn->sock, &server_addr, &len) == -1)
{
char sebuf[256];
@ -519,10 +519,14 @@ verify_peer(PGconn *conn)
return -1;
}
/* weird, but legal case */
if (addr.sa_family == AF_UNIX)
return 0;
if (server_addr.sa_family != AF_INET)
{
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("unsupported protocol\n"));
return -1;
}
/* Get the IP addresses of the certificate's common name (CN) */
{
struct hostent hpstr;
char buf[BUFSIZ];
@ -534,11 +538,11 @@ verify_peer(PGconn *conn)
* convert the pqGethostbyname() function call to use getaddrinfo().
*/
pqGethostbyname(conn->peer_cn, &hpstr, buf, sizeof(buf),
&h, &herrno);
&cn_hostentry, &herrno);
}
/* what do we know about the peer's common name? */
if (h == NULL)
/* Did we get an IP address? */
if (cn_hostentry == NULL)
{
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("could not get information about host \"%s\": %s\n"),
@ -546,53 +550,17 @@ verify_peer(PGconn *conn)
return -1;
}
/* does the address match? */
switch (addr.sa_family)
{
case AF_INET:
sin = (struct sockaddr_in *) & addr;
for (s = h->h_addr_list; *s != NULL; s++)
{
if (!memcmp(&sin->sin_addr.s_addr, *s, h->h_length))
return 0;
}
break;
default:
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("unsupported protocol\n"));
return -1;
}
/*
* the prior test should be definitive, but in practice it sometimes
* fails. So we also check the aliases.
*/
for (s = h->h_aliases; *s != NULL; s++)
{
if (pg_strcasecmp(conn->peer_cn, *s) == 0)
/* Does one of the CN's IP addresses match the server's IP address? */
for (s = cn_hostentry->h_addr_list; *s != NULL; s++)
if (!memcmp(&sin->sin_addr.s_addr, *s, cn_hostentry->h_length))
return 0;
}
/* generate protocol-aware error message */
switch (addr.sa_family)
{
case AF_INET:
sin = (struct sockaddr_in *) & addr;
l = ntohl(sin->sin_addr.s_addr);
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext(
"server common name \"%s\" does not resolve to %ld.%ld.%ld.%ld\n"),
conn->peer_cn, (l >> 24) % 0x100, (l >> 16) % 0x100,
(l >> 8) % 0x100, l % 0x100);
break;
default:
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext(
"server common name \"%s\" does not resolve to peer address\n"),
conn->peer_cn);
}
l = ntohl(sin->sin_addr.s_addr);
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext(
"server common name \"%s\" does not resolve to %ld.%ld.%ld.%ld\n"),
conn->peer_cn, (l >> 24) % 0x100, (l >> 16) % 0x100,
(l >> 8) % 0x100, l % 0x100);
return -1;
}
#endif /* NOT_USED */
@ -1049,25 +1017,10 @@ open_client_SSL(PGconn *conn)
}
}
/* check the certificate chain of the server */
#ifdef NOT_USED
/* CLIENT CERTIFICATES NOT REQUIRED bjm 2002-09-26 */
/*
* this eliminates simple man-in-the-middle attacks and simple
* impersonations
* We already checked the server certificate in initialize_SSL()
* using SSL_CTX_set_verify() if root.crt exists.
*/
r = SSL_get_verify_result(conn->ssl);
if (r != X509_V_OK)
{
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("certificate could not be validated: %s\n"),
X509_verify_cert_error_string(r));
close_SSL(conn);
return PGRES_POLLING_FAILED;
}
#endif
/* pull out server distinguished and common names */
conn->peer = SSL_get_peer_certificate(conn->ssl);
@ -1091,17 +1044,8 @@ open_client_SSL(PGconn *conn)
NID_commonName, conn->peer_cn, SM_USER);
conn->peer_cn[SM_USER] = '\0';
/* verify that the common name resolves to peer */
#ifdef NOT_USED
/* CLIENT CERTIFICATES NOT REQUIRED bjm 2002-09-26 */
/*
* this is necessary to eliminate man-in-the-middle attacks and
* impersonations where the attacker somehow learned the server's private
* key
*/
if (verify_peer(conn) == -1)
if (verify_peer_name_matches_certificate(conn) == -1)
{
close_SSL(conn);
return PGRES_POLLING_FAILED;