Libguestfs - Sep 2015 - [PATCH] customize: Create .ssh as 0700 and .ssh/authorized_keys as 0600 (RHBZ#1260778).

Both ssh-copy-id and ssh create .ssh as 0700.  ssh-copy-id creates
.ssh/authorized_keys as 0600.

Thanks: Ryan Sawhill for finding the bug.
---
 customize/ssh_key.ml |  4 ++--
 src/guestfs.pod      | 17 +++++++++++++++++
 2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/customize/ssh_key.ml b/customize/ssh_key.ml
index 09664bf..dd6056f 100644
--- a/customize/ssh_key.ml
+++ b/customize/ssh_key.ml
@@ -119,14 +119,14 @@ let do_ssh_inject_unix (g : Guestfs.guestfs) user selector
let ssh_dir = sprintf "%s/.ssh" home_dir in
   if not (g#exists ssh_dir) then (
     g#mkdir ssh_dir;
-    g#chmod 0o755 ssh_dir
+    g#chmod 0o700 ssh_dir
   );
 
   (* Create ~user/.ssh/authorized_keys if it doesn't exist. *)
   let auth_keys = sprintf "%s/authorized_keys" ssh_dir in
   if not (g#exists auth_keys) then (
     g#touch auth_keys;
-    g#chmod 0o644 auth_keys
+    g#chmod 0o600 auth_keys
   );
 
   (* Append the key. *)
diff --git a/src/guestfs.pod b/src/guestfs.pod
index 75afa9d..366d6f5 100644
--- a/src/guestfs.pod
+++ b/src/guestfs.pod
@@ -2244,6 +2244,23 @@ allowed a malformed filesystem to take over the
appliance.
 
 If you use sVirt to confine qemu, that would thwart some attacks.
 
+=head2 Permissions of F<.ssh> and F<.ssh/authorized_keys>
+
+L<https://bugzilla.redhat.com/1260778>
+
+The tools L<virt-customize(1)>, L<virt-sysprep(1)> and
+L<virt-builder(1)> have an I<--ssh-inject> option for injecting an
SSH
+key into virtual machine disk images.  They may create a F<~user/.ssh>
+directory and F<~user/.ssh/authorized_keys> file in the guest to do
+this.
+
+In libguestfs E<lt> 1.31.5 and libguestfs E<lt> 1.30.1, the new
+directory and file would get mode C<0755> and mode C<0644>
+respectively.  However these permissions (especially for
+F<~user/.ssh>) are wider than the permissions that OpenSSH uses.  In
+current libguestfs, the directory and file are created with mode
+C<0700> and mode C<0600>.
+
 =head1 CONNECTION MANAGEMENT
 
 =head2 guestfs_h *
-- 
2.5.0

On Monday 07 September 2015 22:16:47 Richard W.M. Jones
wrote:
> Both ssh-copy-id and ssh create .ssh as 0700.  ssh-copy-id creates
> .ssh/authorized_keys as 0600.
> 
> Thanks: Ryan Sawhill for finding the bug.
Mostly LGTM, except ...
> ---
>  customize/ssh_key.ml |  4 ++--
>  src/guestfs.pod      | 17 +++++++++++++++++
>  2 files changed, 19 insertions(+), 2 deletions(-)
> 
> diff --git a/customize/ssh_key.ml b/customize/ssh_key.ml
> index 09664bf..dd6056f 100644
> --- a/customize/ssh_key.ml
> +++ b/customize/ssh_key.ml
> @@ -119,14 +119,14 @@ let do_ssh_inject_unix (g : Guestfs.guestfs) user
selector >    let ssh_dir = sprintf "%s/.ssh" home_dir in
>    if not (g#exists ssh_dir) then (
>      g#mkdir ssh_dir;
> -    g#chmod 0o755 ssh_dir
> +    g#chmod 0o700 ssh_dir
>    );
>  
>    (* Create ~user/.ssh/authorized_keys if it doesn't exist. *)
>    let auth_keys = sprintf "%s/authorized_keys" ssh_dir in
>    if not (g#exists auth_keys) then (
>      g#touch auth_keys;
> -    g#chmod 0o644 auth_keys
> +    g#chmod 0o600 auth_keys
>    );
>  
>    (* Append the key. *)
> diff --git a/src/guestfs.pod b/src/guestfs.pod
> index 75afa9d..366d6f5 100644
> --- a/src/guestfs.pod
> +++ b/src/guestfs.pod
> @@ -2244,6 +2244,23 @@ allowed a malformed filesystem to take over the
appliance.
>  
>  If you use sVirt to confine qemu, that would thwart some attacks.
>  
> +=head2 Permissions of F<.ssh> and F<.ssh/authorized_keys>
> +
> +L<https://bugzilla.redhat.com/1260778>
> +
> +The tools L<virt-customize(1)>, L<virt-sysprep(1)> and
> +L<virt-builder(1)> have an I<--ssh-inject> option for
injecting an SSH
> +key into virtual machine disk images.  They may create a
F<~user/.ssh>
> +directory and F<~user/.ssh/authorized_keys> file in the guest to do
> +this.
> +
> +In libguestfs E<lt> 1.31.5 and libguestfs E<lt> 1.30.1, the
new
... the stable version here, which should be < 1.30.2.
> +directory and file would get mode C<0755> and mode C<0644>
> +respectively.  However these permissions (especially for
> +F<~user/.ssh>) are wider than the permissions that OpenSSH uses.  In
> +current libguestfs, the directory and file are created with mode
> +C<0700> and mode C<0600>.
> +
>  =head1 CONNECTION MANAGEMENT
>  
>  =head2 guestfs_h *
> 
Thanks,
-- 
Pino Toscano