- (djm) Update CygWin support from Corinna Vinschen <vinschen@cygnus.com>

1 files changed, 66 insertions, 0 deletions

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