[Buildroot] [PATCH 1/2] target: add option to set the root password

[Buildroot] [PATCH 1/2] target: add option to set the root password

[Yann E. MORIN]

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.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
---
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(-)

diff --git a/support/dependencies/dependencies.sh b/support/dependencies/dependencies.sh
index 9f0f6a9..edf49e9 100755
--- a/support/dependencies/dependencies.sh
+++ b/support/dependencies/dependencies.sh
@@ -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
diff --git a/target/generic/Config.in b/target/generic/Config.in
index b8472f4..b376c85 100644
--- a/target/generic/Config.in
+++ b/target/generic/Config.in
@@ -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
diff --git a/target/generic/Makefile.in b/target/generic/Makefile.in
index 4185202..1021b10 100644
--- a/target/generic/Makefile.in
+++ b/target/generic/Makefile.in
@@ -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
-- 
1.7.2.5

[Buildroot] [pull request v3] Pull request for branch yem-root-passwd

[Yann E. MORIN]

Hello All!

This is iteration #3 for setting the root password from the configuration
menu:
  - first patch adds the basic functionality:
    - plain text password in menuconfig
    - MD5-encrypted in /etc/shadow
  - second patch adds additional encryption methods

There has been previous review of this series by Arnout, who suggested
dropping patch #2, and only use an MD5-encrypted password. Since MD5 is now
considered to be a weak hash, stronger alternatives may be usefull for the
security-conscious lurking among us. That's why I kept (resurrected) that
second patch.

Arnout also objected to having the root password in clear in the .config,
and recommended that the user enters the already-encrypted password. That
has, IMHO, a few drawbacks, in that it requires the user actually _reads_
the help text, switch to an alternate terminal, generates a password, and
copy-pastes it back in the initial terminal with the menuconfig. OTOH, if
the user forgets his/her password, he/she can recover it by looking at the
.config file. That's why I still advocates for entering a clear-text
password in the menuconfig.

Any more comments are welcome!

The following changes since commit 4848386446b937d4d0d9d3e9489932ca3fcb1003:

  libffi: fix mips build failures (2012-12-28 16:55:09 +0100)

are available in the git repository at:
  git://gitorious.org/buildroot/buildroot.git yem-root-passwd

Yann E. MORIN (2):
      target: add option to set the root password
      target: add different methods to encode the root password

 support/dependencies/dependencies.sh |    9 +++++
 system/Config.in                     |   67 ++++++++++++++++++++++++++++++++++
 system/system.mk                     |   15 ++++++++
 3 files changed, 91 insertions(+), 0 deletions(-)

Regards,
Yann E. MORIN

-- 
.-----------------.--------------------.------------------.--------------------.
|  Yann E. MORIN  | Real-Time Embedded | /"\ ASCII RIBBON | Erics' conspiracy: |
| +33 662 376 056 | Software  Designer | \ / CAMPAIGN     |  ___               |
| +33 223 225 172 `------------.-------:  X  AGAINST      |  \e/  There is no  |
| http://ymorin.is-a-geek.org/ | _/*\_ | / \ HTML MAIL    |   v   conspiracy.  |
'------------------------------^-------^------------------^--------------------'

[Buildroot] [PATCH 1/2] target: add option to set the root password

[Yann E. MORIN]

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 MD5 (MD5 is not the default for crypt(3), DES-56 is, but
MD5 is widely available, not-so-strong, but not-so-weak either).

Add a check for 'mkpasswd' as a new dependency.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Arnout Vandecappelle <arnout@mind.be>
---
Switched to using MD5 as per Arnout's suggestion:
    http://lists.busybox.net/pipermail/buildroot/2012-September/058712.html
---
 support/dependencies/dependencies.sh |    9 +++++++++
 system/Config.in                     |   21 +++++++++++++++++++++
 system/system.mk                     |   14 ++++++++++++++
 3 files changed, 44 insertions(+), 0 deletions(-)

diff --git a/support/dependencies/dependencies.sh b/support/dependencies/dependencies.sh
index 7a02512..c86a5d0 100755
--- a/support/dependencies/dependencies.sh
+++ b/support/dependencies/dependencies.sh
@@ -158,6 +158,7 @@ if grep ^BR2_TOOLCHAIN_BUILDROOT=y $CONFIG_FILE > /dev/null && \
        exit 1 ;
    fi
 fi
+
 if grep -q ^BR2_PACKAGE_CLASSPATH=y $CONFIG_FILE ; then
     for prog in javac jar; do
 	if ! which $prog > /dev/null ; then
@@ -166,3 +167,11 @@ if grep -q ^BR2_PACKAGE_CLASSPATH=y $CONFIG_FILE ; then
 	fi
     done
 fi
+
+if grep -E '^TARGET_GENERIC_ROOT_PASSWD=".+"$' $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
diff --git a/system/Config.in b/system/Config.in
index a557ea0..deead86 100644
--- a/system/Config.in
+++ b/system/Config.in
@@ -12,6 +12,27 @@ 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 (in clear). It will be md5-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!
+	  Although pretty strong, MD5 is now an old hash function, and
+	  suffers from som weaknesses, which makes it susceptible to attacks.
+	  It is showing its age, so this root password should not be trusted
+	  to properly secure any product that can be shipped to the wide,
+	  hostile world.
+	  
+	  WARNING! WARNING!
+	  The password appears in clear in the .config file, and may appear
+	  in 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
diff --git a/system/system.mk b/system/system.mk
index 353d0ba..a23feef 100644
--- a/system/system.mk
+++ b/system/system.mk
@@ -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))
 TARGET_GENERIC_GETTY_TERM:=$(call qstrip,$(BR2_TARGET_GENERIC_GETTY_TERM))
@@ -14,6 +15,13 @@ 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="$$( mkpasswd -m md5 "$(TARGET_GENERIC_ROOT_PASSWD)" )"; \
+	$(SED) "s,^root::,root:$${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) $(TARGET_GENERIC_GETTY_TERM) #~' \
 		$(TARGET_DIR)/etc/inittab
@@ -40,6 +48,12 @@ ifneq ($(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
-- 
1.7.2.5

[Buildroot] [PATCH 2/2] target: add different methods to encode the root password

[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 'md5'.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
---
 system/Config.in |   46 ++++++++++++++++++++++++++++++++++++++++++++++
 system/system.mk |    3 ++-
 2 files changed, 48 insertions(+), 1 deletions(-)

diff --git a/system/Config.in b/system/Config.in
index deead86..2c90e8a 100644
--- a/system/Config.in
+++ b/system/Config.in
@@ -34,6 +34,52 @@ config BR2_TARGET_GENERIC_ROOT_PASSWD
 	  .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_MD5
+
+config BR2_TARGET_GENERIC_ROOT_PASSWD_DES
+	bool "des"
+	help
+	  Use standard 56-bit DES-based crypt(3).
+	  
+	  Old, wildly available, but also the weakest.
+
+config BR2_TARGET_GENERIC_ROOT_PASSWD_MD5
+	bool "md5"
+	help
+	  Use MD5 to encode the password.
+	  
+	  The default, 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
 
diff --git a/system/system.mk b/system/system.mk
index a23feef..f5a8310 100644
--- a/system/system.mk
+++ b/system/system.mk
@@ -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))
 TARGET_GENERIC_GETTY_TERM:=$(call qstrip,$(BR2_TARGET_GENERIC_GETTY_TERM))
@@ -19,7 +20,7 @@ target-no-root-passwd:
 	$(SED) "s/^root:[^:]*:/root::/" $(TARGET_DIR)/etc/shadow
 
 target-root-passwd:
-	root_passwd="$$( mkpasswd -m md5 "$(TARGET_GENERIC_ROOT_PASSWD)" )"; \
+	root_passwd="$$( 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:
-- 
1.7.2.5

[Buildroot] [PATCH 1/2] target: add option to set the root password

[Thomas Petazzoni]

Dear Yann E. MORIN,

On Fri, 28 Dec 2012 22:20:53 +0100, Yann E. MORIN wrote:
> 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 MD5 (MD5 is not the default for crypt(3), DES-56 is, but
> MD5 is widely available, not-so-strong, but not-so-weak either).
> 
> Add a check for 'mkpasswd' as a new dependency.
> 
> Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
> Cc: Arnout Vandecappelle <arnout@mind.be>
> ---
> Switched to using MD5 as per Arnout's suggestion:
>     http://lists.busybox.net/pipermail/buildroot/2012-September/058712.html
> ---
>  support/dependencies/dependencies.sh |    9 +++++++++
>  system/Config.in                     |   21 +++++++++++++++++++++
>  system/system.mk                     |   14 ++++++++++++++
>  3 files changed, 44 insertions(+), 0 deletions(-)
> 
> diff --git a/support/dependencies/dependencies.sh b/support/dependencies/dependencies.sh
> index 7a02512..c86a5d0 100755
> --- a/support/dependencies/dependencies.sh
> +++ b/support/dependencies/dependencies.sh
> @@ -158,6 +158,7 @@ if grep ^BR2_TOOLCHAIN_BUILDROOT=y $CONFIG_FILE > /dev/null && \
>         exit 1 ;
>     fi
>  fi
> +
>  if grep -q ^BR2_PACKAGE_CLASSPATH=y $CONFIG_FILE ; then
>      for prog in javac jar; do
>  	if ! which $prog > /dev/null ; then
> @@ -166,3 +167,11 @@ if grep -q ^BR2_PACKAGE_CLASSPATH=y $CONFIG_FILE ; then
>  	fi
>      done
>  fi
> +
> +if grep -E '^TARGET_GENERIC_ROOT_PASSWD=".+"$' $CONFIG_FILE > /dev/null 2>&1; then

I guess it should be BR2_TARGET_GENERIC_ROOT_PASSWD since you have a ^
at the beginning of the regexp.

> +    if ! which mkpasswd > /dev/null 2>&1; then
> +        /bin/echo -e "\nYou need the 'mkpasswd' utility to set the root password\n"

Also mention that mkpasswd is typically bundled within the whois
package in distros (at least in Debian/Ubuntu), because it may not be
very obvious.

Thomas
-- 
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com

[Buildroot] [PATCH 1/2] target: add option to set the root password

[Yann E. MORIN]

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 MD5 (MD5 is not the default for crypt(3), DES-56 is, but
MD5 is widely available, not-so-strong, but not-so-weak either).

Add a check for 'mkpasswd' as a new dependency.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Arnout Vandecappelle <arnout@mind.be>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
---
Switched to using MD5 as per Arnout's suggestion:
    http://lists.busybox.net/pipermail/buildroot/2012-September/058712.html
---
 support/dependencies/dependencies.sh |    9 +++++++++
 system/Config.in                     |   21 +++++++++++++++++++++
 system/system.mk                     |   14 ++++++++++++++
 3 files changed, 44 insertions(+), 0 deletions(-)

diff --git a/support/dependencies/dependencies.sh b/support/dependencies/dependencies.sh
index 7a02512..eb5a481 100755
--- a/support/dependencies/dependencies.sh
+++ b/support/dependencies/dependencies.sh
@@ -158,6 +158,7 @@ if grep ^BR2_TOOLCHAIN_BUILDROOT=y $CONFIG_FILE > /dev/null && \
        exit 1 ;
    fi
 fi
+
 if grep -q ^BR2_PACKAGE_CLASSPATH=y $CONFIG_FILE ; then
     for prog in javac jar; do
 	if ! which $prog > /dev/null ; then
@@ -166,3 +167,11 @@ if grep -q ^BR2_PACKAGE_CLASSPATH=y $CONFIG_FILE ; then
 	fi
     done
 fi
+
+if grep -E '^BR2_TARGET_GENERIC_ROOT_PASSWD=".+"$' $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"
+        /bin/echo -e "(in Debian/ubuntu, 'mkpasswd' provided by the whois package)\n"
+        exit 1
+    fi
+fi
diff --git a/system/Config.in b/system/Config.in
index a557ea0..deead86 100644
--- a/system/Config.in
+++ b/system/Config.in
@@ -12,6 +12,27 @@ 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 (in clear). It will be md5-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!
+	  Although pretty strong, MD5 is now an old hash function, and
+	  suffers from som weaknesses, which makes it susceptible to attacks.
+	  It is showing its age, so this root password should not be trusted
+	  to properly secure any product that can be shipped to the wide,
+	  hostile world.
+	  
+	  WARNING! WARNING!
+	  The password appears in clear in the .config file, and may appear
+	  in 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
diff --git a/system/system.mk b/system/system.mk
index 353d0ba..a23feef 100644
--- a/system/system.mk
+++ b/system/system.mk
@@ -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))
 TARGET_GENERIC_GETTY_TERM:=$(call qstrip,$(BR2_TARGET_GENERIC_GETTY_TERM))
@@ -14,6 +15,13 @@ 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="$$( mkpasswd -m md5 "$(TARGET_GENERIC_ROOT_PASSWD)" )"; \
+	$(SED) "s,^root::,root:$${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) $(TARGET_GENERIC_GETTY_TERM) #~' \
 		$(TARGET_DIR)/etc/inittab
@@ -40,6 +48,12 @@ ifneq ($(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
-- 
1.7.2.5

[Buildroot] [PATCH 1/2] target: add option to set the root password

[Peter Korsgaard]

>>>>> "Yann" == Yann E MORIN <yann.morin.1998@free.fr> writes:

 Yann> Add an option in the menuconfig to specify a root password.
 Yann> If set to empty, no root password is created; otherwise, the password is
 Yann> encrypted using MD5 (MD5 is not the default for crypt(3), DES-56 is, but
 Yann> MD5 is widely available, not-so-strong, but not-so-weak either).

 Yann> Add a check for 'mkpasswd' as a new dependency.

 Yann> Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
 Yann> Cc: Arnout Vandecappelle <arnout@mind.be>
 Yann> Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
 
 Yann> +config BR2_TARGET_GENERIC_ROOT_PASSWD
 Yann> +	string "root password"

The rest of the options here are capitilized, so I've done that as well
here.

 Yann> +	default ""
 Yann> +	help
 Yann> +	  Set the initial root password (in clear). It will be md5-encrypted.
 Yann> +	  
 Yann> +	  If set to empty (the default), then no root password will be set,
 Yann> +	  and root will need no password to log in.
 Yann> +	  
 Yann> +	  WARNING! WARNING!
 Yann> +	  Although pretty strong, MD5 is now an old hash function, and
 Yann> +	  suffers from som weaknesses, which makes it susceptible to attacks.

s/som/some/

 Yann> +target-no-root-passwd:
 Yann> +	$(SED) "s/^root:[^:]*:/root::/" $(TARGET_DIR)/etc/shadow
 Yann> +
 Yann> +target-root-passwd:
 Yann> +	root_passwd="$$( mkpasswd -m md5 "$(TARGET_GENERIC_ROOT_PASSWD)" )"; \
 Yann> +	$(SED) "s,^root::,root:$${root_passwd}:," $(TARGET_DIR)/etc/shadow
 Yann> +

The 2nd sed only applies if the root passwd isn't set (E.G. running make
menuconfig and changing password + make doesn't work), so I've
simplified the two cases together to simply replace root:[^:]*: with
root:$(TARGET_GENERIC_ROOT_PASSWD_HASH): which is either the empty
string or the mkpasswd -m md5 output.

-- 
Bye, Peter Korsgaard