tree 45b9da03b1fa2132cf4ec76060c63be4c8cac14f
parent a3150fa514dde605a1e90e1ae28ab6c034bd0fa1
author Zev Weiss <zev@bewilderbeest.net> 1631316161 -0500
committer Patrick Williams <patrick@stwcx.xyz> 1631879521 +0000

dropbear: use OpenSSH's sftp-server

OpenSSH recently switched their scp client to default to using the sftp
protocol instead of the legacy scp protocol [0].  There's still an
opt-in flag (-O) available to switch it back, but it'd be nicer to not
require it, and avoid the (sometimes problematic, security-wise)
escaping/interpretation quirks of the scp protocol.  (This also allows
using other file-transfer clients like sftp and sshfs.)  We're already
compiling dropbear with sftp support anyway, it's just missing the
sftp-server binary.

Tested: in an e3c246d4i build, this increased the squashfs image size by
48KiB, or about 0.25%.  With it installed, an OpenSSH scp binary
compiled from current upstream HEAD (commit b0ec59a708b4) could
successfully transfer files to and from the BMC both with and without
the '-O' flag.

[0] https://lists.mindrot.org/pipermail/openssh-unix-dev/2021-September/039616.html

Signed-off-by: Zev Weiss <zev@bewilderbeest.net>
Change-Id: I533046cfc85f90307c188ad42ca5c2cedeadfab4