Corinna Vinschen
2001-Jul-11 20:37 UTC
[PATCH]: Cygwin: Allow sshd to switch user context without password
Hi,
the following patch checks if OpenSSH is running under a Cygwin
version >= 1.3.2 which allows switching user context without password.
Otherwise sshd allows changing the user context only if password
authentication is used as it was before.
Corinna
Index: openbsd-compat/bsd-cygwin_util.c
==================================================================RCS file:
/cvs/openssh_cvs/openbsd-compat/bsd-cygwin_util.c,v
retrieving revision 1.4
diff -u -p -r1.4 bsd-cygwin_util.c
--- openbsd-compat/bsd-cygwin_util.c 2001/04/13 14:28:42 1.4
+++ openbsd-compat/bsd-cygwin_util.c 2001/07/11 20:35:40
@@ -21,10 +21,14 @@ RCSID("$Id: bsd-cygwin_util.c,v 1.4 2001
#include <fcntl.h>
#include <stdlib.h>
+#include <sys/utsname.h>
#include <sys/vfs.h>
#include <windows.h>
#define is_winnt (GetVersion() < 0x80000000)
+#define ntsec_on(c) ((c) && strstr((c),"ntsec") &&
!strstr((c),"nontsec"))
+#define ntea_on(c) ((c) && strstr((c),"ntea") &&
!strstr((c),"nontea"))
+
#if defined(open) && open == binary_open
# undef open
#endif
@@ -61,12 +65,34 @@ int check_nt_auth(int pwd_authenticated,
* context on NT systems is the password authentication. So
* we deny all requsts for changing the user context if another
* authentication method is used.
- * This may change in future when a special openssh
- * subauthentication package is available.
+ *
+ * This doesn't apply to Cygwin versions >= 1.3.2 anymore which
+ * uses the undocumented NtCreateToken() call to create a user
+ * token if the process has the appropriate privileges and if
+ * CYGWIN ntsec setting is on.
*/
- if (is_winnt && !pwd_authenticated && geteuid() != uid)
- return 0;
-
+ static int has_create_token = -1;
+
+ if (is_winnt) {
+ if (has_create_token < 0) {
+ struct utsname uts;
+ int major_high = 0, major_low = 0, minor = 0;
+ char *cygwin = getenv("CYGWIN");
+
+ has_create_token = 0;
+ if (ntsec_on(cygwin) && !uname(&uts)) {
+ sscanf(uts.release, "%d.%d.%d",
+ &major_high, &major_low, &minor);
+ if (major_high > 1 ||
+ (major_high == 1 && (major_low > 3 ||
+ (major_low == 3 && minor >= 2))))
+ has_create_token = 1;
+ }
+ }
+ if (has_create_token < 1 &&
+ !pwd_authenticated && geteuid() != uid)
+ return 0;
+ }
return 1;
}
@@ -82,12 +108,9 @@ int check_ntsec(const char *filename)
return 0;
/* Evaluate current CYGWIN settings. */
- if ((cygwin = getenv("CYGWIN")) != NULL) {
- if (strstr(cygwin, "ntea") && !strstr(cygwin,
"nontea"))
- allow_ntea = 1;
- if (strstr(cygwin, "ntsec") && !strstr(cygwin,
"nontsec"))
- allow_ntsec = 1;
- }
+ cygwin = getenv("CYGWIN");
+ allow_ntea = ntea_on(cygwin);
+ allow_ntsec = ntsec_on(cygwin);
/*
* `ntea' is an emulation of POSIX attributes. It doesn't support
--
Corinna Vinschen
Cygwin Developer
Red Hat, Inc.
mailto:vinschen at redhat.com
Corinna Vinschen
2001-Jul-17 09:20 UTC
[PATCH]: Cygwin: Allow sshd to switch user context without password
On Wed, Jul 11, 2001 at 10:37:54PM +0200, Corinna Vinschen wrote:> Hi, > > the following patch checks if OpenSSH is running under a Cygwin > version >= 1.3.2 which allows switching user context without password. > Otherwise sshd allows changing the user context only if password > authentication is used as it was before. > > Corinna > [...]Just a question: Does nobody review/apply patches at the moment? Vacation time? Corinna -- Corinna Vinschen Cygwin Developer Red Hat, Inc. mailto:vinschen at redhat.com
mouring at etoh.eviladmin.org
2001-Jul-18 16:14 UTC
[PATCH]: Cygwin: Allow sshd to switch user context without password
Applied. Along with the document/ssh-host-config update. Thanks. On Wed, 11 Jul 2001, Corinna Vinschen wrote:> Hi, > > the following patch checks if OpenSSH is running under a Cygwin > version >= 1.3.2 which allows switching user context without password. > Otherwise sshd allows changing the user context only if password > authentication is used as it was before. > > Corinna > > Index: openbsd-compat/bsd-cygwin_util.c > ==================================================================> RCS file: /cvs/openssh_cvs/openbsd-compat/bsd-cygwin_util.c,v > retrieving revision 1.4 > diff -u -p -r1.4 bsd-cygwin_util.c > --- openbsd-compat/bsd-cygwin_util.c 2001/04/13 14:28:42 1.4 > +++ openbsd-compat/bsd-cygwin_util.c 2001/07/11 20:35:40 > @@ -21,10 +21,14 @@ RCSID("$Id: bsd-cygwin_util.c,v 1.4 2001 > > #include <fcntl.h> > #include <stdlib.h> > +#include <sys/utsname.h> > #include <sys/vfs.h> > #include <windows.h> > #define is_winnt (GetVersion() < 0x80000000) > > +#define ntsec_on(c) ((c) && strstr((c),"ntsec") && !strstr((c),"nontsec")) > +#define ntea_on(c) ((c) && strstr((c),"ntea") && !strstr((c),"nontea")) > + > #if defined(open) && open == binary_open > # undef open > #endif > @@ -61,12 +65,34 @@ int check_nt_auth(int pwd_authenticated, > * context on NT systems is the password authentication. So > * we deny all requsts for changing the user context if another > * authentication method is used. > - * This may change in future when a special openssh > - * subauthentication package is available. > + * > + * This doesn't apply to Cygwin versions >= 1.3.2 anymore which > + * uses the undocumented NtCreateToken() call to create a user > + * token if the process has the appropriate privileges and if > + * CYGWIN ntsec setting is on. > */ > - if (is_winnt && !pwd_authenticated && geteuid() != uid) > - return 0; > - > + static int has_create_token = -1; > + > + if (is_winnt) { > + if (has_create_token < 0) { > + struct utsname uts; > + int major_high = 0, major_low = 0, minor = 0; > + char *cygwin = getenv("CYGWIN"); > + > + has_create_token = 0; > + if (ntsec_on(cygwin) && !uname(&uts)) { > + sscanf(uts.release, "%d.%d.%d", > + &major_high, &major_low, &minor); > + if (major_high > 1 || > + (major_high == 1 && (major_low > 3 || > + (major_low == 3 && minor >= 2)))) > + has_create_token = 1; > + } > + } > + if (has_create_token < 1 && > + !pwd_authenticated && geteuid() != uid) > + return 0; > + } > return 1; > } > > @@ -82,12 +108,9 @@ int check_ntsec(const char *filename) > return 0; > > /* Evaluate current CYGWIN settings. */ > - if ((cygwin = getenv("CYGWIN")) != NULL) { > - if (strstr(cygwin, "ntea") && !strstr(cygwin, "nontea")) > - allow_ntea = 1; > - if (strstr(cygwin, "ntsec") && !strstr(cygwin, "nontsec")) > - allow_ntsec = 1; > - } > + cygwin = getenv("CYGWIN"); > + allow_ntea = ntea_on(cygwin); > + allow_ntsec = ntsec_on(cygwin); > > /* > * `ntea' is an emulation of POSIX attributes. It doesn't support > > -- > Corinna Vinschen > Cygwin Developer > Red Hat, Inc. > mailto:vinschen at redhat.com >