Skip to content

sched/nsh: Remove Hard-coded Default Password #18396

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
Abhishekmishra2808 wants to merge 1 commit into
base: master
Choose a base branch
from
+323 −39
Open

sched/nsh: Remove Hard-coded Default Password #18396

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
23 changes: 12 additions & 11 deletions Documentation/platforms/renesas/rx65n/boards/rx65n-grrose/index.rst
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -491,21 +491,22 @@ mounted at /etc and will look like this at run-time:
nsh>

``/etc/init.d/rc.sysinit`` is system init script; ``/etc/init.d/rcS`` is the
start-up script; ``/etc/passwd`` is a the password file. It supports a single
user:
start-up script; ``/etc/passwd`` is the password file.

.. code:: text
The ``/etc/passwd`` file is auto-generated at build time when
``CONFIG_ETC_ROMFS_GENPASSWD`` is enabled. To configure the admin user and
password, run ``make menuconfig`` and set:

USERNAME: admin
PASSWORD: Administrator
* ``CONFIG_ETC_ROMFS_GENPASSWD=y``
* ``CONFIG_ETC_ROMFS_PASSWD_USER`` (default: ``admin``)
* ``CONFIG_ETC_ROMFS_PASSWD_PASSWORD`` (required, build fails if empty)

nsh> cat /etc/passwd
admin:8Tv+Hbmr3pLVb5HHZgd26D:0:0:/
The password is hashed with TEA at build time using
``tools/mkpasswd.py``; the plaintext is **not** stored in the firmware.

The encrypted passwords in the provided passwd file are only valid if the TEA
key is set to: 012345678 9abcdef0 012345678 9abcdef0. Changes to either the key
or the password word will require regeneration of the ``nsh_romfimg.h`` header
Copy link
Contributor

@cederom cederom Feb 15, 2026

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

This information was important because it explained how key was related to firmware code, where it was stored, and how to update. I would not remove it. Merge result should be more informative not less :-)

file.
The encrypted passwords are only valid if the TEA key matches the one
configured in ``CONFIG_FSUTILS_PASSWD_KEY1..4`` (default:
``012345678 9abcdef0 012345678 9abcdef0``).

The format of the password file is:

Expand Down
22 changes: 13 additions & 9 deletions Documentation/platforms/risc-v/esp32c3-legacy/boards/esp32c3-legacy-devkit/ROMFS.txt
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -23,18 +23,22 @@ README
nsh>

/etc/init.d/rc.sysinit is system init script; /etc/init.d/rcS is the start-up
script; /etc/passwd is a the password file. It supports a single user:
script; /etc/passwd is the password file.

USERNAME: admin
PASSWORD: Administrator
The /etc/passwd file is auto-generated at build time when
CONFIG_ETC_ROMFS_GENPASSWD is enabled. To configure the admin user and
password, run 'make menuconfig' and set:

nsh> cat /etc/passwd
admin:8Tv+Hbmr3pLVb5HHZgd26D:0:0:/
CONFIG_ETC_ROMFS_GENPASSWD=y
CONFIG_ETC_ROMFS_PASSWD_USER (default: admin)
CONFIG_ETC_ROMFS_PASSWD_PASSWORD (required, build fails if empty)

The encrypted passwords in the provided passwd file are only valid if the
TEA key is set to: 012345678 9abcdef0 012345678 9abcdef0. Changes to either
the key or the password word will require regeneration of the nsh_romfimg.h
header file.
The password is hashed with TEA at build time using tools/mkpasswd.py;
the plaintext is NOT stored in the firmware image.

The encrypted passwords are only valid if the TEA key matches the one
configured in CONFIG_FSUTILS_PASSWD_KEY1..4 (default:
012345678 9abcdef0 012345678 9abcdef0).

The format of the password file is:

Expand Down
26 changes: 12 additions & 14 deletions Documentation/platforms/sim/sim/boards/sim/index.rst
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2008,24 +2008,22 @@ mounted at ``/etc`` and will look like this at run-time:
nsh>
``/etc/init.d/rc.sysinit`` is system init script; ``/etc/init.d/rcS`` is the
start-up script; ``/etc/passwd`` is a the password file. It supports a single
user:
start-up script; ``/etc/passwd`` is the password file.

.. code:: text
USERNAME: admin
PASSWORD: Administrator
.. code:: console
The ``/etc/passwd`` file is auto-generated at build time when
``CONFIG_ETC_ROMFS_GENPASSWD`` is enabled. To configure the admin user and
password, run ``make menuconfig`` and set:

nsh> cat /etc/passwd
admin:8Tv+Hbmr3pLVb5HHZgd26D:0:0:/
* ``CONFIG_ETC_ROMFS_GENPASSWD=y``
* ``CONFIG_ETC_ROMFS_PASSWD_USER`` (default: ``admin``)
* ``CONFIG_ETC_ROMFS_PASSWD_PASSWORD`` (required, build fails if empty)

The encrypted passwords in the provided passwd file are only valid if the
TEA key is set to: 012345678 9abcdef0 012345678 9abcdef0.
The password is hashed with TEA at build time using
``tools/mkpasswd.py``; the plaintext is **not** stored in the firmware.
Comment on lines +2017 to +2022
Copy link
Contributor

@linguini1 linguini1 Feb 15, 2026

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Not critical, but maybe this documentation which is repeated for multiple boards could be put somewhere common (i.e. a page about password usage) and then linked to from these boards instead.


Changes to either the key or the password word will require regeneration of the
``nsh_romfimg.h`` header file.
The encrypted passwords are only valid if the TEA key matches the one
configured in ``CONFIG_FSUTILS_PASSWD_KEY1..4`` (default:
``012345678 9abcdef0 012345678 9abcdef0``).

The format of the password file is:

Expand Down
13 changes: 13 additions & 0 deletions boards/Board.mk
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -35,6 +35,19 @@ $(ETCSRC): $(foreach raw,$(RCRAWS), $(if $(wildcard $(BOARD_DIR)$(DELIM)src$(DEL
$(shell rm -rf $(ETCDIR)$(DELIM)$(raw)) \
$(shell mkdir -p $(dir $(ETCDIR)$(DELIM)$(raw))) \
$(shell cp -rfp $(if $(wildcard $(BOARD_DIR)$(DELIM)src$(DELIM)$(raw)), $(BOARD_DIR)$(DELIM)src$(DELIM)$(raw), $(if $(wildcard $(BOARD_COMMON_DIR)$(DELIM)$(raw)), $(BOARD_COMMON_DIR)$(DELIM)$(raw), $(BOARD_DIR)$(DELIM)src$(DELIM)$(raw))) $(ETCDIR)$(DELIM)$(raw)))
ifeq ($(CONFIG_ETC_ROMFS_GENPASSWD),y)
ifeq ($(CONFIG_ETC_ROMFS_PASSWD_PASSWORD),)
$(error CONFIG_ETC_ROMFS_PASSWD_PASSWORD must be set when ETC_ROMFS_GENPASSWD is enabled. Run 'make menuconfig' to set a password.)
endif
$(Q) mkdir -p $(ETCDIR)$(DELIM)$(CONFIG_ETC_ROMFSMOUNTPT)
$(Q) python3 $(TOPDIR)$(DELIM)tools$(DELIM)mkpasswd.py \
Copy link
Contributor

@cederom cederom Feb 15, 2026

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

this introduces python3 as mandatory build component, which may not be welcome, and it was not necessary, so probably there it another way :-)

--user $(CONFIG_ETC_ROMFS_PASSWD_USER) \
--password $(CONFIG_ETC_ROMFS_PASSWD_PASSWORD) \
--uid $(CONFIG_ETC_ROMFS_PASSWD_UID) \
--gid $(CONFIG_ETC_ROMFS_PASSWD_GID) \
--home $(CONFIG_ETC_ROMFS_PASSWD_HOME) \
-o $(ETCDIR)$(DELIM)$(CONFIG_ETC_ROMFSMOUNTPT)$(DELIM)passwd
endif
$(Q) genromfs -f romfs.img -d $(ETCDIR)$(DELIM)$(CONFIG_ETC_ROMFSMOUNTPT) -V "NSHInitVol"
$(Q) echo "#include <nuttx/compiler.h>" > $@
$(Q) xxd -i romfs.img | sed -e "s/^unsigned char/const unsigned char aligned_data(4)/g" >> $@
Expand Down
2 changes: 1 addition & 1 deletion boards/risc-v/esp32c3-legacy/esp32c3-legacy-devkit/src/Make.defs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -46,7 +46,7 @@ endif

ifeq ($(CONFIG_ETC_ROMFS),y)
RCSRCS = etc/init.d/rc.sysinit etc/init.d/rcS
RCRAWS = etc/group etc/passwd
RCRAWS = etc/group
endif

DEPPATH += --dep-path board
Expand Down
1 change: 0 additions & 1 deletion boards/risc-v/esp32c3-legacy/esp32c3-legacy-devkit/src/etc/passwd
View file
Open in desktop

This file was deleted.

1 change: 0 additions & 1 deletion boards/sim/sim/sim/src/CMakeLists.txt
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -77,7 +77,6 @@ if(CONFIG_ETC_ROMFS)
etc/init.d/rc.sysinit
RCRAWS
etc/group
etc/passwd
PATH
${CMAKE_CURRENT_BINARY_DIR}/etc)

Expand Down
2 changes: 1 addition & 1 deletion boards/sim/sim/sim/src/Makefile
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -56,7 +56,7 @@ endif

ifeq ($(CONFIG_ETC_ROMFS),y)
RCSRCS = etc/init.d/rc.sysinit etc/init.d/rcS
RCRAWS = etc/group etc/passwd
RCRAWS = etc/group
endif

ifeq ($(CONFIG_ARCH_BUTTONS),y)
Expand Down
1 change: 0 additions & 1 deletion boards/sim/sim/sim/src/etc/passwd
View file
Open in desktop

This file was deleted.

27 changes: 27 additions & 0 deletions cmake/nuttx_add_romfs.cmake
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -282,6 +282,33 @@ function(process_all_directory_romfs)
list(PREPEND RCSRCS ${board_rcsrcs} ${dyn_rcsrcs})
list(PREPEND RCRAWS ${board_rcraws} ${dyn_rcraws})

# Auto-generate /etc/passwd at build time if configured
if(CONFIG_ETC_ROMFS_GENPASSWD)
if("${CONFIG_ETC_ROMFS_PASSWD_PASSWORD}" STREQUAL "")
message(
FATAL_ERROR
"CONFIG_ETC_ROMFS_PASSWD_PASSWORD must be set when"
" ETC_ROMFS_GENPASSWD is enabled."
" Run 'make menuconfig' to set a password.")
endif()

set(GENPASSWD_OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/etc/passwd)
add_custom_command(
OUTPUT ${GENPASSWD_OUTPUT}
COMMAND
${CMAKE_COMMAND} -E make_directory ${CMAKE_CURRENT_BINARY_DIR}/etc
COMMAND
${Python3_EXECUTABLE} ${NUTTX_DIR}/tools/mkpasswd.py --user
"${CONFIG_ETC_ROMFS_PASSWD_USER}" --password
"${CONFIG_ETC_ROMFS_PASSWD_PASSWORD}" --uid
${CONFIG_ETC_ROMFS_PASSWD_UID} --gid ${CONFIG_ETC_ROMFS_PASSWD_GID}
--home "${CONFIG_ETC_ROMFS_PASSWD_HOME}" -o ${GENPASSWD_OUTPUT}
COMMENT "Generating /etc/passwd from Kconfig values")
add_custom_target(generate_passwd DEPENDS ${GENPASSWD_OUTPUT})
list(APPEND RCRAWS ${GENPASSWD_OUTPUT})
list(APPEND dyn_deps generate_passwd)
endif()

# init dynamic dependencies

get_property(
Expand Down
40 changes: 40 additions & 0 deletions sched/Kconfig
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -623,6 +623,46 @@ config ETC_FATMOUNTPT
will mount a FAT FS under /tmp. This is the location where the FAT
FS will be mounted. Default is "/tmp".

config ETC_ROMFS_GENPASSWD
Copy link
Contributor

@cederom cederom Feb 15, 2026 •
edited
Loading

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

ETC_ROMFS_PASSWD_ENABLE?
So it is aligned with other kconfig variables and its ETC_ROMFS_PASSWD_ group:

ETC_ROMFS_PASSWD_ENABLE
ETC_ROMFS_PASSWD_USERNAME
ETC_ROMFS_PASSWD_PASSWORD
ETC_ROMFS_PASSWD_UID
ETC_ROMFS_PASSWD_GID
ETC_ROMFS_PASSWD_HOME

bool "Auto-generate /etc/passwd at build time"
default n
---help---
Generate the /etc/passwd file at build time from a user-supplied
password. This avoids shipping a hard-coded default password
(CWE-798). When enabled, the build will fail if no password
is configured, forcing each build to set its own credentials.

if ETC_ROMFS_GENPASSWD
Copy link
Contributor

@xiaoxiang781216 xiaoxiang781216 Feb 24, 2026

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

should you move the opion to boards/Kconfig and add BOARD_ prefix


config ETC_ROMFS_PASSWD_USER
string "Admin username"
default "admin"
---help---
The username for the auto-generated /etc/passwd entry.

config ETC_ROMFS_PASSWD_PASSWORD
string "Admin password (required)"
default ""
---help---
The plaintext password for the auto-generated /etc/passwd entry.
This value is hashed with TEA at build time; the plaintext is NOT
stored in the firmware image. The build will fail if this is left
empty. Set this via 'make menuconfig'.

config ETC_ROMFS_PASSWD_UID
int "Admin user ID"
default 0

config ETC_ROMFS_PASSWD_GID
int "Admin group ID"
default 0

config ETC_ROMFS_PASSWD_HOME
string "Admin home directory"
default "/"

endif # ETC_ROMFS_GENPASSWD

endif # ETC_ROMFS

config RR_INTERVAL
Expand Down
Loading
Loading