Allow harmless group-writability

Allow secure files (~/.ssh/config, ~/.ssh/authorized_keys, etc.) to be
group-writable, provided that the group in question contains only the file's
owner.  Rejected upstream for IMO incorrect reasons (e.g. a misunderstanding
about the contents of gr->gr_mem).  Given that per-user groups and umask 002
are the default setup in Debian (for good reasons - this makes operating in
setgid directories with other groups much easier), we need to permit this by
default.

Bug: https://bugzilla.mindrot.org/show_bug.cgi?id=1060
Bug-Debian: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=314347
Last-Update: 2017-10-04

Patch-Name: user-group-modes.patch

1 files changed, 2 insertions, 0 deletions

diff --git a/misc.h b/misc.h
index 6be289fd2..213c3abb7 100644
--- a/misc.h
+++ b/misc.h
@@ -167,6 +167,8 @@ int	 safe_path_fd(int, const char *, struct passwd *,
 char    *read_passphrase(const char *, int);
 int      ask_permission(const char *, ...) __attribute__((format(printf, 1, 2)));
 
+int      secure_permissions(struct stat *st, uid_t uid);
+
 #define MINIMUM(a, b)   (((a) < (b)) ? (a) : (b))
 #define MAXIMUM(a, b)   (((a) > (b)) ? (a) : (b))
 #define ROUNDUP(x, y)   ((((x)+((y)-1))/(y))*(y))