target: add option to set the root password
PATCH 1/2 target: add option to set the root password
Add an option in the menuconfig to specify a root password.
If set to empty, no root password is created; otherwise, the password is encrypted using DES-56 (other mechanisms will come in a future patch), because DES-56 is the standard default using crypt(3).
Add a check for 'mkpasswd' as a new dependency.
---
This will clash with Thomas' pending reorganising series:
http://lists.busybox.net/pipermail/buildroot/2012-September/058254.html --- support/dependencies/dependencies.sh | 7 +++++++ target/generic/Config.in | 14 ++++++++++++++ target/generic/Makefile.in | 14 ++++++++++++++ 3 files changed, 35 insertions(+), 0 deletions(-)
support/dependencies/dependencies.sh +7 -0
@@ -158,3 +158,10 @@ if grep ^BR2_TOOLCHAIN_BUILDROOT=y $CONFIG_FILE > /dev/null && \ exit 1 ; fi fi + +if grep -E '^TARGET_GENERIC_ROOT_PASSWD=".+"$' $CONFIG_FILE > /dev/null 2>&1; then + if ! which mkpasswd > /dev/null 2>&1; then + /bin/echo -e "\nYou need the 'mkpasswd' utility to set the root password\n" + exit 1 + fi +fi
target/generic/Config.in +14 -0
@@ -12,6 +12,20 @@ config BR2_TARGET_GENERIC_ISSUE help Select system banner (/etc/issue) to be displayed at login. +config BR2_TARGET_GENERIC_ROOT_PASSWD + string "root password" + default "" + help + Set the initial root password. It will be des56-encrypted. + + If set to empty (the default), then no root password will be set, + and root will need no password to log in. + + WARNING! WARNING! + The password appears in clear in the .config file, and may + appear in the the build log! Avoid using a valuable password + if either the .config file or the build log may be distributed! + choice prompt "/dev management" default BR2_ROOTFS_DEVICE_CREATION_STATIC
target/generic/Makefile.in +14 -0
@@ -1,5 +1,6 @@ TARGET_GENERIC_HOSTNAME:=$(call qstrip,$(BR2_TARGET_GENERIC_HOSTNAME)) TARGET_GENERIC_ISSUE:=$(call qstrip,$(BR2_TARGET_GENERIC_ISSUE)) +TARGET_GENERIC_ROOT_PASSWD:=$(call qstrip,$(BR2_TARGET_GENERIC_ROOT_PASSWD)) TARGET_GENERIC_GETTY:=$(call qstrip,$(BR2_TARGET_GENERIC_GETTY_PORT)) TARGET_GENERIC_GETTY_BAUDRATE:=$(call qstrip,$(BR2_TARGET_GENERIC_GETTY_BAUDRATE))
@@ -13,6 +14,13 @@ target-generic-issue: mkdir -p $(TARGET_DIR)/etc echo "$(TARGET_GENERIC_ISSUE)" > $(TARGET_DIR)/etc/issue +target-no-root-passwd: + $(SED) "s/^root:[^:]*:/root::/" $(TARGET_DIR)/etc/shadow + +target-root-passwd: + root_passwd="$$( mkpasswd -m des "$(TARGET_GENERIC_ROOT_PASSWD)" )"; \ + $(SED) "s,^root::,root:$${root_passwd}:," $(TARGET_DIR)/etc/shadow + target-generic-getty-busybox: $(SED) '/# GENERIC_SERIAL$$/s~^.*#~$(TARGET_GENERIC_GETTY)::respawn:/sbin/getty -L $(TARGET_GENERIC_GETTY) $(TARGET_GENERIC_GETTY_BAUDRATE) vt100 #~' \ $(TARGET_DIR)/etc/inittab
@@ -39,6 +47,12 @@ ifneq ($(TARGET_GENERIC_ISSUE),) TARGETS += target-generic-issue endif +ifneq ($(TARGET_GENERIC_ROOT_PASSWD),) +TARGETS += target-root-passwd +else +TARGETS += target-no-root-passwd +endif + ifeq ($(BR2_ROOTFS_SKELETON_DEFAULT),y) ifeq ($(BR2_PACKAGE_SYSVINIT),y) TARGETS += target-generic-getty-sysvinit
Signature · 1 line
1.7.2.5
PATCH 2/2 target: add different methods to encode the root password
The password can be encoded in different ways (from the weakest to the strongest): des, md5, sha-256, sha-512
Add a choice entry to select the method, defaulting to 'des'.
--- target/generic/Config.in | 46 ++++++++++++++++++++++++++++++++++++++++++++ target/generic/Makefile.in | 3 +- 2 files changed, 48 insertions(+), 1 deletions(-)
target/generic/Config.in +46 -0
@@ -27,6 +27,52 @@ config BR2_TARGET_GENERIC_ROOT_PASSWD if either the .config file or the build log may be distributed! choice + bool "root password encoding" + depends on BR2_TARGET_GENERIC_ROOT_PASSWD != "" + default BR2_TARGET_GENERIC_ROOT_PASSWD_DES + +config BR2_TARGET_GENERIC_ROOT_PASSWD_DES + bool "des" + help + Use standard 56-bit DES-based crypt(3). + + The default, wildly available, but also the weakest. + +config BR2_TARGET_GENERIC_ROOT_PASSWD_MD5 + bool "md5" + help + Use MD5 to encode the password. + + Although not default, still wildly available, and pretty good. + +config BR2_TARGET_GENERIC_ROOT_PASSWD_SHA256 + bool "sha-256" + help + Use SHA256 to encode the password. + + Very strong, but not ubiquitous, although available in glibc + for some time now. Choose only if you are sure your C library + understands SHA256 passwords. + +config BR2_TARGET_GENERIC_ROOT_PASSWD_SHA512 + bool "sha-512" + help + Use SHA512 to encode the password. + + Extremely strong, but not ubiquitous, although available in glibc + for some time now. Choose only if you are sure your C library + understands SHA512 passwords. + +endchoice # root passwd encoding + +config BR2_TARGET_GENERIC_ROOT_PASSWD_METHOD + string + default "des" if BR2_TARGET_GENERIC_ROOT_PASSWD_DES + default "md5" if BR2_TARGET_GENERIC_ROOT_PASSWD_MD5 + default "sha-256" if BR2_TARGET_GENERIC_ROOT_PASSWD_SHA256 + default "sha-512" if BR2_TARGET_GENERIC_ROOT_PASSWD_SHA512 + +choice prompt "/dev management" default BR2_ROOTFS_DEVICE_CREATION_STATIC
target/generic/Makefile.in +2 -1
@@ -1,6 +1,7 @@ TARGET_GENERIC_HOSTNAME:=$(call qstrip,$(BR2_TARGET_GENERIC_HOSTNAME)) TARGET_GENERIC_ISSUE:=$(call qstrip,$(BR2_TARGET_GENERIC_ISSUE)) TARGET_GENERIC_ROOT_PASSWD:=$(call qstrip,$(BR2_TARGET_GENERIC_ROOT_PASSWD)) +TARGET_GENERIC_ROOT_PASSWD_METHOD:=$(call qstrip,$(BR2_TARGET_GENERIC_ROOT_PASSWD_METHOD)) TARGET_GENERIC_GETTY:=$(call qstrip,$(BR2_TARGET_GENERIC_GETTY_PORT)) TARGET_GENERIC_GETTY_BAUDRATE:=$(call qstrip,$(BR2_TARGET_GENERIC_GETTY_BAUDRATE))
@@ -18,7 +19,7 @@ target-no-root-passwd: $(SED) "s/^root:[^:]*:/root::/" $(TARGET_DIR)/etc/shadow target-root-passwd: - root_passwd="$$( mkpasswd -m des "$(TARGET_GENERIC_ROOT_PASSWD)" )"; \ + root_passwd="$$( mkpasswd -m "$(TARGET_GENERIC_ROOT_PASSWD_METHOD)" "$(TARGET_GENERIC_ROOT_PASSWD)" )"; \ $(SED) "s,^root::,root:$${root_passwd}:," $(TARGET_DIR)/etc/shadow target-generic-getty-busybox:
Signature · 1 line
1.7.2.5
PATCH 2/2 target: add different methods to encode the root password
Quoted 6 lines · Yann E. MORIN
The password can be encoded in different ways (from the weakest to the strongest): des, md5, sha-256, sha-512
Add a choice entry to select the method, defaulting to 'des'.
Signed-off-by "Yann E. MORIN"<[email protected]>
I think this is going way too far for just setting the root password. I would just
make it an md5 crypt (which is supported by all uClibc versions) and be done with it.
Regards,
Arnout
Signature · 6 lines
Arnout Vandecappelle arnout at mind be Senior Embedded Software Architect +32-16-286540 Essensium/Mind http://www.mind.be G.Geenslaan 9, 3001 Leuven, Belgium BE 872 984 063 RPR Leuven LinkedIn profile: http://www.linkedin.com/in/arnoutvandecappelle GPG fingerprint: 7CB5 E4CC 6C2E EFD4 6E3D A754 F963 ECAB 2450 2F1F
PATCH 2/2 target: add different methods to encode the root password
Arnout, All,
Quoted 11 lines · On Wednesday 19 September 2012 00:04:25 Arnout Vandecappelle wrote:
Quoted 6 lines · Yann E. MORIN
The password can be encoded in different ways (from the weakest to the strongest): des, md5, sha-256, sha-512
Add a choice entry to select the method, defaulting to 'des'.
Signed-off-by "Yann E. MORIN"<[email protected]>I think this is going way too far for just setting the root password. I would just make it an md5 crypt (which is supported by all uClibc versions) and be done with it.
OK, I'll respin a single patch with only MD5-encrypted password.
To be noted however, is that MD5 is now sensible to attacks:
http://www.kb.cert.org/vuls/id/836068
There's even an attack that can find collisions within seconds on a P4:
http://www.win.tue.nl/hashclash/On%20Collisions%20for%20MD5%20-%20M.M.J.%20Stevens.pdf
Thus, I'll add to the help text that this should not be considered for production use for publicly-reachable devices (eg. appliances...), and that the security of the device should not rely on the root password being strongly-enough encrypted; something in this vein...
Regards,
Yann E. MORIN.
Signature · 6 lines
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