users, by limiting the length of string we will accept for a password.
Patch by Serguei Mokhov, some editorializing by Tom Lane.
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/libpq/auth.c,v 1.90 2002/09/04 20:31:18 momjian Exp $
+ * $Header: /cvsroot/pgsql/src/backend/libpq/auth.c,v 1.91 2002/09/04 23:31:34 tgl Exp $
*
*-------------------------------------------------------------------------
*/
{
sendAuthRequest(pam_port_cludge, AUTH_REQ_PASSWORD);
if (pq_eof() == EOF || pq_getint(&len, 4) == EOF)
- {
return PAM_CONV_ERR; /* client didn't want to send password */
- }
initStringInfo(&buf);
- pq_getstr(&buf);
+ if (pq_getstr_bounded(&buf, 1000) == EOF)
+ return PAM_CONV_ERR; /* EOF while reading password */
/* Do not echo failed password to logs, for security. */
elog(DEBUG5, "received PAM packet");
return STATUS_EOF; /* client didn't want to send password */
initStringInfo(&buf);
- if (pq_getstr(&buf) == EOF) /* receive password */
+ if (pq_getstr_bounded(&buf, 1000) == EOF) /* receive password */
{
pfree(buf.data);
return STATUS_EOF;
/*-------------------------------------------------------------------------
*
- * be-connect.c
+ * be-secure.c
* functions related to setting up a secure connection to the frontend.
* Secure connections are expected to provide confidentiality,
* message integrity and endpoint authentication.
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/libpq/be-secure.c,v 1.13 2002/09/04 20:31:19 momjian Exp $
+ * $Header: /cvsroot/pgsql/src/backend/libpq/be-secure.c,v 1.14 2002/09/04 23:31:34 tgl Exp $
*
* Since the server static private key ($DataDir/server.key)
* will normally be stored unencrypted so that the database
* Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $Id: pqcomm.c,v 1.140 2002/09/04 20:31:19 momjian Exp $
+ * $Id: pqcomm.c,v 1.141 2002/09/04 23:31:34 tgl Exp $
*
*-------------------------------------------------------------------------
*/
* The return value is placed in an expansible StringInfo.
* Note that space allocation comes from the current memory context!
*
+ * If maxlen is not zero, it is an upper limit on the length of the
+ * string we are willing to accept. We abort the connection (by
+ * returning EOF) if client tries to send more than that. Note that
+ * since we test maxlen in the outer per-bufferload loop, the limit
+ * is fuzzy: we might accept up to PQ_BUFFER_SIZE more bytes than
+ * specified. This is fine for the intended purpose, which is just
+ * to prevent DoS attacks from not-yet-authenticated clients.
+ *
* NOTE: this routine does not do any character set conversion,
* even though it is presumably useful only for text, because
* no code in this module should depend on the encoding.
- * See pq_getstr in pqformat.c for that.
+ * See pq_getstr_bounded in pqformat.c for that.
*
* returns 0 if OK, EOF if trouble
* --------------------------------
*/
int
-pq_getstring(StringInfo s)
+pq_getstring(StringInfo s, int maxlen)
{
int i;
s->len = 0;
s->data[0] = '\0';
- /* Read until we get the terminating '\0' */
+ /* Read until we get the terminating '\0' or overrun maxlen */
for (;;)
{
while (PqRecvPointer >= PqRecvLength)
}
/* If we're here we haven't got the \0 in the buffer yet. */
-
appendBinaryStringInfo(s, PqRecvBuffer + PqRecvPointer,
PqRecvLength - PqRecvPointer);
PqRecvPointer = PqRecvLength;
+
+ /* If maxlen is specified, check for overlength input. */
+ if (maxlen > 0 && s->len > maxlen)
+ return EOF;
}
}
* Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $Id: pqformat.c,v 1.24 2002/09/03 21:45:42 petere Exp $
+ * $Id: pqformat.c,v 1.25 2002/09/04 23:31:35 tgl Exp $
*
*-------------------------------------------------------------------------
*/
* pq_puttextmessage - generate a character set-converted message in one step
*
* Message input:
- * pq_getint - get an integer from connection
- * pq_getstr - get a null terminated string from connection
- * pq_getstr performs character set conversion on the collected string.
- * Use the raw pqcomm.c routines pq_getstring or pq_getbytes
+ * pq_getint - get an integer from connection
+ * pq_getstr_bounded - get a null terminated string from connection
+ * pq_getstr_bounded performs character set conversion on the collected
+ * string. Use the raw pqcomm.c routines pq_getstring or pq_getbytes
* to fetch data without conversion.
*/
}
/* --------------------------------
- * pq_getstr - get a null terminated string from connection
+ * pq_getstr_bounded - get a null terminated string from connection
*
* The return value is placed in an expansible StringInfo.
* Note that space allocation comes from the current memory context!
*
+ * The maxlen parameter is interpreted as per pq_getstring.
+ *
* returns 0 if OK, EOF if trouble
* --------------------------------
*/
int
-pq_getstr(StringInfo s)
+pq_getstr_bounded(StringInfo s, int maxlen)
{
int result;
char *p;
- result = pq_getstring(s);
+ result = pq_getstring(s, maxlen);
p = (char *) pg_client_to_server((unsigned char *) s->data, s->len);
if (p != s->data) /* actual conversion has been done? */
* Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $Id: libpq.h,v 1.51 2002/06/20 20:29:49 momjian Exp $
+ * $Id: libpq.h,v 1.52 2002/09/04 23:31:35 tgl Exp $
*
*-------------------------------------------------------------------------
*/
extern void StreamClose(int sock);
extern void pq_init(void);
extern int pq_getbytes(char *s, size_t len);
-extern int pq_getstring(StringInfo s);
+extern int pq_getstring(StringInfo s, int maxlen);
extern int pq_getbyte(void);
extern int pq_peekbyte(void);
extern int pq_putbytes(const char *s, size_t len);
* Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $Id: pqformat.h,v 1.12 2002/06/20 20:29:49 momjian Exp $
+ * $Id: pqformat.h,v 1.13 2002/09/04 23:31:35 tgl Exp $
*
*-------------------------------------------------------------------------
*/
extern int pq_puttextmessage(char msgtype, const char *str);
extern int pq_getint(int *result, int b);
-extern int pq_getstr(StringInfo s);
+extern int pq_getstr_bounded(StringInfo s, int maxlen);
+
+#define pq_getstr(s) pq_getstr_bounded(s, 0)
#endif /* PQFORMAT_H */
OSDN Git Service
