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Add Secure Boot Kernel configuration #298

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merged 9 commits into from
Feb 2, 2023
Merged

Add Secure Boot Kernel configuration #298

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9e53a97
[secure boot]Add Linux Kernel configuration to support Secure Boot fe…
davidpil2002 Nov 13, 2022
9724e9f
[secure boot]Fix few typos
davidpil2002 Nov 14, 2022
10322c3
[secure boot]Fix Secure boot build flag condition by adding an extra …
davidpil2002 Nov 14, 2022
77e1842
[secure boot]Remove WA after the fix in commit 5717c5d391092f2a8f894e…
davidpil2002 Dec 15, 2022
b6003e9
[secure boot]Add secure boot kernel config by using kconfig-secure-bo…
davidpil2002 Jan 25, 2023
b6b6c59
[secure boot]removed comment, rename certificate with the name of the…
davidpil2002 Jan 25, 2023
46beeb3
[secure boot]Fix equal condition and add input file validation to cer…
davidpil2002 Jan 26, 2023
fb8993f
[secure boot]Add signature force flag in kernel config, to force kern…
davidpil2002 Jan 31, 2023
9eb7646
Merge branch 'master' into secure_boot_support
saiarcot895 Feb 2, 2023
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4 changes: 3 additions & 1 deletion Makefile
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Original file line number Diff line number Diff line change
Expand Up @@ -9,6 +9,8 @@ KERNEL_VERSION ?= 5.10.140
KERNEL_SUBVERSION ?= 1
kernel_procure_method ?= build
CONFIGURED_ARCH ?= amd64
SECURE_UPGRADE_MODE ?=
SECURE_UPGRADE_DEV_SIGNING_CERT =?

LINUX_HEADER_COMMON = linux-headers-$(KVERSION_SHORT)-common_$(KERNEL_VERSION)-$(KERNEL_SUBVERSION)_all.deb
LINUX_HEADER_AMD64 = linux-headers-$(KVERSION)_$(KERNEL_VERSION)-$(KERNEL_SUBVERSION)_$(CONFIGURED_ARCH).deb
Expand Down Expand Up @@ -123,7 +125,7 @@ $(addprefix $(DEST)/, $(MAIN_TARGET)): $(DEST)/% :

# Optionally add/remove kernel options
if [ -f ../manage-config ]; then
../manage-config $(CONFIGURED_ARCH) $(CONFIGURED_PLATFORM)
../manage-config $(CONFIGURED_ARCH) $(CONFIGURED_PLATFORM) $(SECURE_UPGRADE_MODE) $(SECURE_UPGRADE_DEV_SIGNING_CERT)
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fi

# Building a custom kernel from Debian kernel source
Expand Down
184 changes: 114 additions & 70 deletions manage-config
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Expand Up @@ -26,12 +26,21 @@
# Configuration file to change
ARCH=amd64
PLATFORM=
SECURE_UPGRADE_MODE="no_sign"
SECURE_UPGRADE_DEV_SIGNING_CERT=
if [ $# -ge 1 ]; then
ARCH=$1
fi
if [ $# -ge 2 ]; then
PLATFORM=$2
fi
if [ $# -ge 3 ]; then
SECURE_UPGRADE_MODE=$3
fi
if [ $# -ge 4 ]; then
SECURE_UPGRADE_DEV_SIGNING_CERT=$4
fi

case "$ARCH" in
amd64)
CONFIG_FILE_LOC=debian/build/build_amd64_none_amd64
Expand All @@ -58,88 +67,123 @@ function get_section_opts(){
echo "$opts"
}

ret=0
exclusion_file="../patch/kconfig-exclusions"
inclusion_file="../patch/kconfig-inclusions"
force_inclusion_file="../patch/kconfig-force-inclusions"
if [ -e ${exclusion_file} -o -e ${inclusion_file} -o -e ${force_inclusion_file} ]; then

# Process any exclusions in the kernel
if [ -f ${exclusion_file} ]; then
exclusion_opts=$(get_section_opts ${exclusion_file} "common" ${ARCH} ${PLATFORM})
while read -r opt; do
if [ ! -z "$opt" ] && [[ ! "$opt" =~ ^#.* ]]; then
scripts/config --file ${CONFIG_FILE} -d $opt
fi
done <<< ${exclusion_opts};
fi
function process_inclusion_exclusion_files(){
echo "process_inclusion_exclusion_files Start"
ret=0
echo "debug ret=$ret 1"
if [ -e ${exclusion_file} -o -e ${inclusion_file} -o -e ${force_inclusion_file} ]; then

# Process any inclusions in the kernel
if [ -f ${inclusion_file} ]; then
inclusion_opts=$(get_section_opts ${inclusion_file} "common" ${ARCH} ${PLATFORM})
while read -r opt; do
if [ ! -z "$opt" ] && [[ ! "$opt" =~ ^#.* ]]; then
n=${opt%=*}
v="${opt#*=}"
scripts/config --file ${CONFIG_FILE} -k --set-val "$n" "$v"
fi
done <<< ${inclusion_opts};
fi
# Process any exclusions in the kernel
if [ -f ${exclusion_file} ]; then
exclusion_opts=$(get_section_opts ${exclusion_file} "common" ${ARCH} ${PLATFORM})
while read -r opt; do
if [ ! -z "$opt" ] && [[ ! "$opt" =~ ^#.* ]]; then
scripts/config --file ${CONFIG_FILE} -d $opt
fi
done <<< ${exclusion_opts};
fi

# Update the .config file to be sure it's consistent
make -C ${CONFIG_FILE_LOC} olddefconfig
# Process any inclusions in the kernel
if [ -f ${inclusion_file} ]; then
inclusion_opts=$(get_section_opts ${inclusion_file} "common" ${ARCH} ${PLATFORM})
while read -r opt; do
if [ ! -z "$opt" ] && [[ ! "$opt" =~ ^#.* ]]; then
n=${opt%=*}
v="${opt#*=}"
scripts/config --file ${CONFIG_FILE} -k --set-val "$n" "$v"
fi
done <<< ${inclusion_opts};
fi

# Verify that the kernel options we want to remove are not in the updated configuration
if [ -f ${exclusion_file} ]; then
echo
echo "Checking removed kernel options..."
while read -r opt; do
if [ ! -z "$opt" ] && [[ ! "$opt" =~ ^#.* ]]; then
s=$(scripts/config --file ${CONFIG_FILE} -k --state $opt)
if [ ! "$s" = "undef" -a ! "$s" = "n" ]; then
ret=1
echo "Option $opt should not be set, but is set to [$s]"
# Update the .config file to be sure it's consistent
make -C ${CONFIG_FILE_LOC} olddefconfig

# Verify that the kernel options we want to remove are not in the updated configuration
if [ -f ${exclusion_file} ]; then
echo
echo "Checking removed kernel options..."
while read -r opt; do
if [ ! -z "$opt" ] && [[ ! "$opt" =~ ^#.* ]]; then
s=$(scripts/config --file ${CONFIG_FILE} -k --state $opt)
if [ ! "$s" = "undef" -a ! "$s" = "n" ]; then
ret=1
echo "Option $opt should not be set, but is set to [$s]"
fi
fi
done <<< ${exclusion_opts};
if [ $ret = 0 ]; then
echo "No error"
fi
done <<< ${exclusion_opts};
if [ $ret = 0 ]; then
echo "No error"
fi
fi

# Verify that the kernel options we want to add are now in the updated configuration
if [ -f ${inclusion_file} ]; then
echo
echo "Checking added kernel options..."
while read -r opt; do
if [ ! -z "$opt" ] && [[ ! "$opt" =~ ^#.* ]]; then
n=${opt%=*}
v="${opt#*=}"
v="${v/#\"/}"
v="${v/%\"/}"
s=$(scripts/config --file ${CONFIG_FILE} -k --state $n)
if [ ! "$s" = "$v" ]; then
ret=2
echo "Option $n should be set to [$v] instead of [$s]"
# Verify that the kernel options we want to add are now in the updated configuration
if [ -f ${inclusion_file} ]; then
echo
echo "Checking added kernel options..."
while read -r opt; do
if [ ! -z "$opt" ] && [[ ! "$opt" =~ ^#.* ]]; then
n=${opt%=*}
v="${opt#*=}"
v="${v/#\"/}"
v="${v/%\"/}"
s=$(scripts/config --file ${CONFIG_FILE} -k --state $n)
if [ ! "$s" = "$v" ]; then
ret=2
echo "Option $n should be set to [$v] instead of [$s]"
fi
fi
done <<< ${inclusion_opts};
if [ ! $ret = 2 ]; then
echo "No error"
fi
done <<< ${inclusion_opts};
if [ ! $ret = 2 ]; then
echo "No error"
fi
fi

# Process any force inclusions in the kernel
if [ -f ${force_inclusion_file} ]; then
force_inclusion_opts=$(get_section_opts ${force_inclusion_file} "common" ${ARCH} ${PLATFORM})
while read -r opt; do
if [ ! -z "$opt" ] && [[ ! "$opt" =~ ^#.* ]]; then
echo $opt >> ${CONFIG_FILE}
fi
done <<< ${force_inclusion_opts};
# Process any force inclusions in the kernel
if [ -f ${force_inclusion_file} ]; then
force_inclusion_opts=$(get_section_opts ${force_inclusion_file} "common" ${ARCH} ${PLATFORM})
while read -r opt; do
if [ ! -z "$opt" ] && [[ ! "$opt" =~ ^#.* ]]; then
echo $opt >> ${CONFIG_FILE}
fi
done <<< ${force_inclusion_opts};
fi

echo
fi

echo
echo "process_inclusion_exclusion_files Done"
return $ret
}

exclusion_file="../patch/kconfig-exclusions"
inclusion_file="../patch/kconfig-inclusions"
force_inclusion_file="../patch/kconfig-force-inclusions"
ret_process_inc_ex=0
ret_process_inc_ex=$(process_inclusion_exclusion_files > /dev/null; echo $?)

# Secure Boot support
if [ $ret_process_inc_ex -eq 0 ]; then
echo "Secure Boot params: SECURE_UPGRADE_MODE=${SECURE_UPGRADE_MODE}, SECURE_UPGRADE_DEV_SIGNING_CERT=${SECURE_UPGRADE_DEV_SIGNING_CERT}"
if [ ${SECURE_UPGRADE_MODE} == "dev" -o ${SECURE_UPGRADE_MODE} == "prod" ]; then
echo "set kconfig-secure-boot-exclusions & kconfig-secure-boot-inclusions"

if [ ! -f "${SECURE_UPGRADE_DEV_SIGNING_CERT}" ]; then
echo "ERROR: SECURE_UPGRADE_DEV_SIGNING_CERT=${SECURE_UPGRADE_DEV_SIGNING_CERT} file does not exist"
exit 1
fi

exclusion_file="../patch/kconfig-secure-boot-exclusions"
inclusion_file="../patch/kconfig-secure-boot-inclusions"
force_inclusion_file="../patch/kconfig-force-secure-boot-inclusions"

# save the new pub key in kernel
sed -i "s|^CONFIG_SYSTEM_TRUSTED_KEYS=.*|CONFIG_SYSTEM_TRUSTED_KEYS=\"$SECURE_UPGRADE_DEV_SIGNING_CERT\"|g" ${inclusion_file}
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ret_process_inc_ex=$(process_inclusion_exclusion_files > /dev/null; echo $?)
echo "Secure Boot kernel configuration done."
else
echo "no Secure Boot Kernel configuration required."
fi
fi

exit $ret
exit $ret_process_inc_ex
21 changes: 21 additions & 0 deletions patch/kconfig-secure-boot-exclusions
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Original file line number Diff line number Diff line change
@@ -0,0 +1,21 @@
[common]

[amd64]
CONFIG_MODULE_SIG_SHA256
# For mellanox
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why these are excluded? can we have more explanation for the justifications?

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@davidpil2002 davidpil2002 Jan 31, 2023 •
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SHA256 is excluded because we are using SHA512. Its more secure.
there is more description in the HLD link attached in the description of this PR.
About the lockdown, we have a plan to support it in the future, for now for Mellanox its disabled.

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I'm planning to move the SHA512 config to apply to all kernel builds in a future PR; this isn't necessarily secure-boot specific, and is nice to have in general.

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I'm planning to move the SHA512 config to apply to all kernel builds in a future PR; this isn't necessarily secure-boot specific, and is nice to have in general.

Sound good, can we for now save the PR as is, and when you modify the general config you can remove it.

Because we are implicitly signing the kernel modules with sha512 in the sonic-buildimage:
https://github.com/sonic-net/sonic-buildimage/pull/12692/files#diff-de80d4961ffb88d808888c6d160af8717e70ec6c21675b0f5124b0d27db7a166
So, if the kernel configuration does not match, the image will not boot.

CONFIG_SECURITY_LOCKDOWN_LSM
CONFIG_SECURITY_LOCKDOWN_LSM_EARLY
CONFIG_LOCK_DOWN_KERNEL_FORCE_NONE
CONFIG_LOCK_DOWN_IN_EFI_SECURE_BOOT

[arm64]
CONFIG_MODULE_SIG_SHA256
# For mellanox
CONFIG_SECURITY_LOCKDOWN_LSM
CONFIG_SECURITY_LOCKDOWN_LSM_EARLY
CONFIG_LOCK_DOWN_KERNEL_FORCE_NONE
CONFIG_LOCK_DOWN_IN_EFI_SECURE_BOOT

[armhf]

[marvell-armhf]
19 changes: 19 additions & 0 deletions patch/kconfig-secure-boot-inclusions
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@@ -0,0 +1,19 @@
[common]

[amd64]
CONFIG_SYSTEM_TRUSTED_KEYS="debian/certs/debian-uefi-certs.pem"
CONFIG_MODULE_SIG_HASH="sha512"
CONFIG_MODULE_SIG_SHA512=y
CONFIG_KEXEC_SIG_FORCE=y
CONFIG_MODULE_SIG_FORCE=y

[arm64]
CONFIG_SYSTEM_TRUSTED_KEYS="debian/certs/debian-uefi-certs.pem"
CONFIG_MODULE_SIG_HASH="sha512"
CONFIG_MODULE_SIG_SHA512=y
CONFIG_KEXEC_SIG_FORCE=y
CONFIG_MODULE_SIG_FORCE=y

[armhf]

[marvell-armhf]