5 files changed, 84 insertions, 24 deletions

diff --git a/ChangeLog b/ChangeLog
index 507469abc..b298318e4 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,4 +1,5 @@
 20000916
+ - (djm) Update CygWin support from Corinna Vinschen <vinschen@cygnus.com>
  - (djm) Use a real struct sockaddr inside the fake struct sockaddr_storage.
    Patch from Larry Jones <larry.jones@sdrc.com>
  - (djm) Add Steve VanDevender's <stevev@darkwing.uoregon.edu> PAM 
diff --git a/auth1.c b/auth1.c
index 43faa67f3..99639b59f 100644
--- a/auth1.c
+++ b/auth1.c
@@ -29,11 +29,6 @@ RCSID("$OpenBSD: auth1.c,v 1.4 2000/09/07 20:27:49 deraadt Exp $");
 # include <siad.h>
 #endif
 
-#ifdef HAVE_CYGWIN
-#include <windows.h>
-#define is_winnt       (GetVersion() < 0x80000000)
-#endif
-
 /* import */
 extern ServerOptions options;
 extern char *forced_command;
@@ -383,16 +378,8 @@ do_authloop(struct passwd * pw)
                 }
 
 #ifdef HAVE_CYGWIN
-                /*
-                 * The only authentication which is able to change the user
-                 * 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.
-                 */
-                if (is_winnt && type != SSH_CMSG_AUTH_PASSWORD &&
-                    authenticated && geteuid() != pw->pw_uid) {
+                if (authenticated &&
+                    !check_nt_auth(type == SSH_CMSG_AUTH_PASSWORD,pw->pw_uid)) {
                         packet_disconnect("Authentication rejected for uid %d.",
                                           (int) pw->pw_uid);
                         authenticated = 0;
diff --git a/auth2.c b/auth2.c
index 804afd8d6..8b0a4bc6a 100644
--- a/auth2.c
+++ b/auth2.c
@@ -182,6 +182,15 @@ input_userauth_request(int type, int plen)
                         authenticated = ssh2_auth_pubkey(pw, service);
                 }
         }
+
+#ifdef HAVE_CYGWIN
+        if (authenticated && !check_nt_auth(strcmp(method, "password") == 0, pw->pw_uid)) {
+                packet_disconnect("Authentication rejected for uid %d.",
+                                  (int) pw->pw_uid);
+                authenticated = 0;
+        }
+#endif
+
         if (authenticated && pw && pw->pw_uid == 0 && !options.permit_root_login) {
                 authenticated = 0;
                 log("ROOT LOGIN REFUSED FROM %.200s",
@@ -189,8 +198,8 @@ input_userauth_request(int type, int plen)
         }
 
 #ifdef USE_PAM
-                if (authenticated && !do_pam_account(pw->pw_name, NULL))
-                        authenticated = 0;
+        if (authenticated && !do_pam_account(pw->pw_name, NULL))
+                authenticated = 0;
 #endif /* USE_PAM */
 
         /* Raise logging level */
diff --git a/authfile.c b/authfile.c
index 0a5bae96f..66bdc0ef1 100644
--- a/authfile.c
+++ b/authfile.c
@@ -479,12 +479,10 @@ load_private_key(const char *filename, const char *passphrase, Key *key,
         if (fd < 0)
                 return 0;
 
-#ifndef HAVE_CYGWIN
-        /*
-         * check owner and modes.
-         * This won't work on Windows under all circumstances so we drop
-         * that check for now.
-         */
+        /* check owner and modes.  */
+#ifdef HAVE_CYGWIN
+        if (check_ntsec(filename))
+#endif
         if (fstat(fd, &st) < 0 ||
             (st.st_uid != 0 && st.st_uid != getuid()) ||
             (st.st_mode & 077) != 0) {
@@ -497,7 +495,6 @@ load_private_key(const char *filename, const char *passphrase, Key *key,
                 error("It is recommended that your private key files are NOT accessible by others.");
                 return 0;
         }
-#endif
         switch (key->type) {
         case KEY_RSA:
                 if (key->rsa->e != NULL) {
diff --git a/cygwin_util.c b/cygwin_util.c
index 13bd66347..88748c4fb 100644
--- a/cygwin_util.c
+++ b/cygwin_util.c
@@ -18,6 +18,10 @@
 #ifdef HAVE_CYGWIN
 #include <fcntl.h>
 #include <io.h>
+#include <stdlib.h>
+#include <sys/vfs.h>
+#include <windows.h>
+#define is_winnt       (GetVersion() < 0x80000000)
 
 int binary_open(const char *filename, int flags, mode_t mode)
 {
@@ -31,5 +35,67 @@ int binary_pipe(int fd[2])
                setmode (fd[0], O_BINARY);
                setmode (fd[1], O_BINARY);
        }
+       return ret;
+}
+
+int check_nt_auth (int pwd_authenticated, uid_t uid)
+{
+        /*
+         * The only authentication which is able to change the user
+         * 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.
+         */
+        if (is_winnt && !pwd_authenticated && geteuid() != uid)
+                return 0;
+        return 1;
+}
+
+int check_ntsec (const char *filename)
+{
+        char *cygwin;
+        int allow_ntea = 0;
+        int allow_ntsec = 0;
+        struct statfs fsstat;
+
+        /* Windows 95/98/ME don't support file system security at all. */
+        if (!is_winnt)
+                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;
+        }
+
+        /*
+         * `ntea' is an emulation of POSIX attributes. It doesn't support
+         * real file level security as ntsec on NTFS file systems does
+         * but it supports FAT filesystems. `ntea' is minimum requirement
+         * for security checks.
+         */
+        if (allow_ntea)
+                return 1;
+
+        /*
+         * Retrieve file system flags. In Cygwin, file system flags are
+         * copied to f_type which has no meaning in Win32 itself.
+         */
+        if (statfs(filename, &fsstat))
+                return 1;
+
+        /*
+         * Only file systems supporting ACLs are able to set permissions.
+         * `ntsec' is the setting in Cygwin which switches using of NTFS
+         * ACLs to support POSIX permissions on files.
+         */
+        if (fsstat.f_type & FS_PERSISTENT_ACLS)
+                return allow_ntsec;
+
+        return 0;
 }
 #endif