[PATCH v3 4/4] imx: hab: Use nxp_imx8mcst etype for i.MX8M flash.bin signing
Tim Harvey
tharvey at gateworks.com
Thu May 16 23:40:05 CEST 2024
On Thu, May 16, 2024 at 2:31 PM Marek Vasut <marex at denx.de> wrote:
>
> Update documentation and use nxp_imx8mcst binman etype for signing
> of flash.bin instead of previous horrible shell scripting.
>
> Signed-off-by: Marek Vasut <marex at denx.de>
> ---
> Cc: "NXP i.MX U-Boot Team" <uboot-imx at nxp.com>
> Cc: Adam Ford <aford173 at gmail.com>
> Cc: Alper Nebi Yasak <alpernebiyasak at gmail.com>
> Cc: Andrejs Cainikovs <andrejs.cainikovs at toradex.com>
> Cc: Angus Ainslie <angus at akkea.ca>
> Cc: Emanuele Ghidoli <emanuele.ghidoli at toradex.com>
> Cc: Fabio Estevam <festevam at gmail.com>
> Cc: Francesco Dolcini <francesco.dolcini at toradex.com>
> Cc: Marcel Ziswiler <marcel.ziswiler at toradex.com>
> Cc: Rasmus Villemoes <rasmus.villemoes at prevas.dk>
> Cc: Simon Glass <sjg at chromium.org>
> Cc: Stefan Eichenberger <stefan.eichenberger at toradex.com>
> Cc: Stefano Babic <sbabic at denx.de>
> Cc: Tim Harvey <tharvey at gateworks.com>
> Cc: Tom Rini <trini at konsulko.com>
> Cc: kernel at puri.sm
> Cc: u-boot at dh-electronics.com
> Cc: u-boot at lists.denx.de
> ---
> V2: Document the automatic signing in case CONFIG_IMX_HAB is enabled
> V3: Document configuration of imx8mcst
> ---
> doc/imx/habv4/csf_examples/mx8m/csf.sh | 92 --------------
> doc/imx/habv4/csf_examples/mx8m/csf_fit.txt | 30 -----
> doc/imx/habv4/csf_examples/mx8m/csf_spl.txt | 33 -----
> doc/imx/habv4/guides/mx8m_spl_secure_boot.txt | 116 +++++-------------
> 4 files changed, 30 insertions(+), 241 deletions(-)
> delete mode 100644 doc/imx/habv4/csf_examples/mx8m/csf.sh
> delete mode 100644 doc/imx/habv4/csf_examples/mx8m/csf_fit.txt
> delete mode 100644 doc/imx/habv4/csf_examples/mx8m/csf_spl.txt
>
> diff --git a/doc/imx/habv4/csf_examples/mx8m/csf.sh b/doc/imx/habv4/csf_examples/mx8m/csf.sh
> deleted file mode 100644
> index cd3b2614a2f..00000000000
> --- a/doc/imx/habv4/csf_examples/mx8m/csf.sh
> +++ /dev/null
> @@ -1,92 +0,0 @@
> -#!/bin/sh
> -
> -# 0) Generate keys
> -#
> -# WARNING: ECDSA keys are only supported by HAB 4.5 and newer (i.e. i.MX8M Plus)
> -#
> -# cd /path/to/cst-3.3.1/keys/
> -# ./hab4_pki_tree.sh -existing-ca n -use-ecc n -kl 4096 -duration 10 -num-srk 4 -srk-ca y
> -# cd /path/to/cst-3.3.1/crts/
> -# ../linux64/bin/srktool -h 4 -t SRK_1_2_3_4_table.bin -e SRK_1_2_3_4_fuse.bin -d sha256 -c ./SRK1_sha256_4096_65537_v3_ca_crt.pem,./SRK2_sha256_4096_65537_v3_ca_crt.pem,./SRK3_sha256_4096_65537_v3_ca_crt.pem,./SRK4_sha256_4096_65537_v3_ca_crt.pem -f 1
> -
> -# 1) Build U-Boot (e.g. for i.MX8MM)
> -#
> -# cp -Lv /path/to/arm-trusted-firmware/build/imx8mm/release/bl31.bin .
> -# cp -Lv /path/to/firmware-imx-8.14/firmware/ddr/synopsys/ddr3* .
> -# make -j imx8mm_board_defconfig
> -# make -j`nproc` flash.bin
> -
> -# 2) Sign SPL and DRAM blobs
> -
> -cp doc/imx/habv4/csf_examples/mx8m/csf_spl.txt csf_spl.tmp
> -cp doc/imx/habv4/csf_examples/mx8m/csf_fit.txt csf_fit.tmp
> -
> -# update File Paths from env vars
> -if ! [ -r $CSF_KEY ]; then
> - echo "Error: \$CSF_KEY not found"
> - exit 1
> -fi
> -if ! [ -r $IMG_KEY ]; then
> - echo "Error: \$IMG_KEY not found"
> - exit 1
> -fi
> -if ! [ -r $SRK_TABLE ]; then
> - echo "Error: \$SRK_TABLE not found"
> - exit 1
> -fi
> -sed -i "s:\$CSF_KEY:$CSF_KEY:" csf_spl.tmp
> -sed -i "s:\$IMG_KEY:$IMG_KEY:" csf_spl.tmp
> -sed -i "s:\$SRK_TABLE:$SRK_TABLE:" csf_spl.tmp
> -sed -i "s:\$CSF_KEY:$CSF_KEY:" csf_fit.tmp
> -sed -i "s:\$IMG_KEY:$IMG_KEY:" csf_fit.tmp
> -sed -i "s:\$SRK_TABLE:$SRK_TABLE:" csf_fit.tmp
> -
> -# update SPL Blocks
> -spl_block_base=$(printf "0x%x" $(( $(sed -n "/CONFIG_SPL_TEXT_BASE=/ s at .*=@@p" .config) - 0x40)) )
> -spl_block_size=$(printf "0x%x" $(stat -tc %s u-boot-spl-ddr.bin))
> -sed -i "/Blocks = / s at .*@ Blocks = $spl_block_base 0x0 $spl_block_size \"flash.bin\"@" csf_spl.tmp
> -
> -# Generate CSF blob
> -cst -i csf_spl.tmp -o csf_spl.bin
> -
> -# Patch CSF blob into flash.bin
> -spl_csf_offset=$(xxd -s 24 -l 4 -e flash.bin | cut -d " " -f 2 | sed "s@^@0x@")
> -spl_bin_offset=$(xxd -s 4 -l 4 -e flash.bin | cut -d " " -f 2 | sed "s@^@0x@")
> -spl_dd_offset=$((${spl_csf_offset} - ${spl_bin_offset} + 0x40))
> -dd if=csf_spl.bin of=flash.bin bs=1 seek=${spl_dd_offset} conv=notrunc
> -
> -# 3) Sign u-boot.itb
> -
> -# fitImage
> -fit_block_base=$(printf "0x%x" $(sed -n "/CONFIG_SPL_LOAD_FIT_ADDRESS=/ s at .*=@@p" .config) )
> -fit_block_offset=$(printf "0x%s" $(fdtget -t x u-boot.dtb /binman/imx-boot/uboot offset))
> -fit_block_size=$(printf "0x%x" $(( ( ( $(stat -tc %s u-boot.itb) + 0x1000 - 0x1 ) & ~(0x1000 - 0x1)) + 0x20 )) )
> -sed -i "/Blocks = / s at .*@ Blocks = $fit_block_base $fit_block_offset $fit_block_size \"flash.bin\"@" csf_fit.tmp
> -
> -# IVT
> -ivt_ptr_base=$(printf "%08x" ${fit_block_base} | sed "s@\(..\)\(..\)\(..\)\(..\)@0x\4\3\2\1@")
> -ivt_block_base=$(printf "%08x" $(( ${fit_block_base} + ${fit_block_size} - 0x20 )) | sed "s@\(..\)\(..\)\(..\)\(..\)@0x\4\3\2\1@")
> -csf_block_base=$(printf "%08x" $(( ${fit_block_base} + ${fit_block_size} )) | sed "s@\(..\)\(..\)\(..\)\(..\)@0x\4\3\2\1@")
> -ivt_block_offset=$((${fit_block_offset} + ${fit_block_size} - 0x20))
> -csf_block_offset=$((${ivt_block_offset} + 0x20))
> -
> -echo "0xd1002041 ${ivt_block_base} 0x00000000 0x00000000 0x00000000 ${ivt_block_base} ${csf_block_base} 0x00000000" | xxd -r -p > ivt.bin
> -dd if=ivt.bin of=flash.bin bs=1 seek=${ivt_block_offset} conv=notrunc
> -
> -# Generate CSF blob
> -cst -i csf_fit.tmp -o csf_fit.bin
> -
> -# When loading flash.bin via USB, we must ensure that the file being
> -# served is as large as the target expects (see
> -# board_spl_fit_size_align()), otherwise the target will hang in
> -# rom_api_download_image() waiting for the remaining bytes.
> -#
> -# Note that in order for dd to actually extend the file, one must not
> -# pass conv=notrunc here. With a non-zero seek= argument, dd is
> -# documented to preserve the contents of the file seeked past; in
> -# particular, dd does not open the file with O_TRUNC.
> -CSF_SIZE=$(sed -n "/CONFIG_CSF_SIZE=/ s at .*=@@p" .config)
> -dd if=/dev/null of=csf_fit.bin bs=1 seek=$((CSF_SIZE - 0x20)) count=0
> -
> -# Patch CSF blob into flash.bin
> -dd if=csf_fit.bin of=flash.bin bs=1 seek=${csf_block_offset} conv=notrunc
> diff --git a/doc/imx/habv4/csf_examples/mx8m/csf_fit.txt b/doc/imx/habv4/csf_examples/mx8m/csf_fit.txt
> deleted file mode 100644
> index 97f3eea573b..00000000000
> --- a/doc/imx/habv4/csf_examples/mx8m/csf_fit.txt
> +++ /dev/null
> @@ -1,30 +0,0 @@
> -[Header]
> - Version = 4.3
> - Hash Algorithm = sha256
> - Engine = CAAM
> - Engine Configuration = 0
> - Certificate Format = X509
> - Signature Format = CMS
> -
> -[Install SRK]
> - # SRK_TABLE is full path to SRK_1_2_3_4_table.bin
> - File = "$SRK_TABLE"
> - Source index = 0
> -
> -[Install CSFK]
> - # CSF_KEY is full path to CSF1_1_sha256_4096_65537_v3_usr_crt.pem
> - File = "$CSF_KEY"
> -
> -[Authenticate CSF]
> -
> -[Install Key]
> - Verification index = 0
> - Target Index = 2
> - # IMG_KEY is full path to IMG1_1_sha256_4096_65537_v3_usr_crt.pem
> - File = "$IMG_KEY"
> -
> -[Authenticate Data]
> - Verification index = 2
> - # FIXME:
> - # Line 1 -- fitImage
> - Blocks = CONFIG_SPL_LOAD_FIT_ADDRESS 0x57c00 0xffff "flash.bin"
> diff --git a/doc/imx/habv4/csf_examples/mx8m/csf_spl.txt b/doc/imx/habv4/csf_examples/mx8m/csf_spl.txt
> deleted file mode 100644
> index 88fa420a5fa..00000000000
> --- a/doc/imx/habv4/csf_examples/mx8m/csf_spl.txt
> +++ /dev/null
> @@ -1,33 +0,0 @@
> -[Header]
> - Version = 4.3
> - Hash Algorithm = sha256
> - Engine = CAAM
> - Engine Configuration = 0
> - Certificate Format = X509
> - Signature Format = CMS
> -
> -[Install SRK]
> - # SRK_TABLE is full path to SRK_1_2_3_4_table.bin
> - File = "$SRK_TABLE"
> - Source index = 0
> -
> -[Install CSFK]
> - # CSF_KEY is full path to CSF1_1_sha256_4096_65537_v3_usr_crt.pem
> - File = "$CSF_KEY"
> -
> -[Authenticate CSF]
> -
> -[Unlock]
> - Engine = CAAM
> - Features = MID
> -
> -[Install Key]
> - Verification index = 0
> - Target Index = 2
> - # IMG_KEY is full path to IMG1_1_sha256_4096_65537_v3_usr_crt.pem
> - File = "$IMG_KEY"
> -
> -[Authenticate Data]
> - Verification index = 2
> - # FIXME: Adjust start (first column) and size (third column) here
> - Blocks = 0x7e0fc0 0x0 0x306f0 "flash.bin"
> diff --git a/doc/imx/habv4/guides/mx8m_spl_secure_boot.txt b/doc/imx/habv4/guides/mx8m_spl_secure_boot.txt
> index e16e5410bd9..1eb1fb0aa61 100644
> --- a/doc/imx/habv4/guides/mx8m_spl_secure_boot.txt
> +++ b/doc/imx/habv4/guides/mx8m_spl_secure_boot.txt
> @@ -121,6 +121,9 @@ build configuration:
> - Defconfig:
>
> CONFIG_IMX_HAB=y
> + CONFIG_FSL_CAAM=y
> + CONFIG_ARCH_MISC_INIT=y
> + CONFIG_SPL_CRYPTO=y
>
> - Kconfig:
>
> @@ -131,92 +134,33 @@ build configuration:
>
> The CSF contains all the commands that the HAB executes during the secure
> boot. These commands instruct the HAB code on which memory areas of the image
> -to authenticate, which keys to install, use and etc.
> -
> -CSF examples are available under doc/imx/habv4/csf_examples/ directory.
> -
> -CSF "Blocks" line for csf_spl.txt can be generated as follows:
> -
> -```
> -spl_block_base=$(printf "0x%x" $(( $(sed -n "/CONFIG_SPL_TEXT_BASE=/ s at .*=@@p" .config) - 0x40)) )
> -spl_block_size=$(printf "0x%x" $(stat -tc %s u-boot-spl-ddr.bin))
> -sed -i "/Blocks = / s at .*@ Blocks = $spl_block_base 0x0 $spl_block_size \"flash.bin\"@" csf_spl.txt
> -```
> -
> -The resulting line looks as follows:
> -```
> - Blocks = 0x7e0fc0 0x0 0x306f0 "flash.bin"
> -```
> -
> -The columns mean:
> - - CONFIG_SPL_TEXT_BASE - 0x40 -- Start address of signed data, in DRAM
> - - 0x0 -- Start address of signed data, in "flash.bin"
> - - 0x306f0 -- Length of signed data, in "flash.bin"
> - - Filename -- "flash.bin"
> -
> -To generate signature for the SPL part of flash.bin container, use CST:
> -```
> -cst -i csf_spl.tmp -o csf_spl.bin
> -```
> -
> -The newly generated CST blob has to be patched into existing flash.bin
> -container. Conveniently, flash.bin IVT contains physical address of the
> -CSF blob. Remember, the SPL part of flash.bin container is loaded by the
> -BootROM at CONFIG_SPL_TEXT_BASE - 0x40 , so the offset of CSF blob in
> -the fitImage can be calculated and inserted into the flash.bin in the
> -correct location as follows:
> -```
> -# offset = IVT_HEADER[6 = CSF address] - CONFIG_SPL_TEXT_BASE - 0x40
> -spl_csf_offset=$(xxd -s 24 -l 4 -e flash.bin | cut -d " " -f 2 | sed "s@^@0x@")
> -spl_bin_offset=$(xxd -s 4 -l 4 -e flash.bin | cut -d " " -f 2 | sed "s@^@0x@")
> -spl_dd_offset=$((${spl_csf_offset} - ${spl_bin_offset} + 0x40))
> -dd if=csf_spl.bin of=flash.bin bs=1 seek=${spl_dd_offset} conv=notrunc
> -```
> -
> -CSF "Blocks" line for csf_fit.txt can be generated as follows:
> -```
> -# fitImage
> -fit_block_base=$(printf "0x%x" $(sed -n "/CONFIG_SPL_LOAD_FIT_ADDRESS=/ s at .*=@@p" .config) )
> -fit_block_offset=$(printf "0x%s" $(fdtget -t x u-boot.dtb /binman/imx-boot/uboot offset))
> -fit_block_size=$(printf "0x%x" $(( ( ( $(stat -tc %s u-boot.itb) + 0x1000 - 0x1 ) & ~(0x1000 - 0x1)) + 0x20 )) )
> -sed -i "/Blocks = / s at .*@ Blocks = $fit_block_base $fit_block_offset $fit_block_size \"flash.bin\"@" csf_fit.tmp
> -```
> -
> -The fitImage part of flash.bin requires separate IVT. Generate the IVT and
> -patch it into the correct aligned location of flash.bin as follows:
> -```
> -# IVT
> -ivt_ptr_base=$(printf "%08x" ${fit_block_base} | sed "s@\(..\)\(..\)\(..\)\(..\)@0x\4\3\2\1@")
> -ivt_block_base=$(printf "%08x" $(( ${fit_block_base} + ${fit_block_size} - 0x20 )) | sed "s@\(..\)\(..\)\(..\)\(..\)@0x\4\3\2\1@")
> -csf_block_base=$(printf "%08x" $(( ${fit_block_base} + ${fit_block_size} )) | sed "s@\(..\)\(..\)\(..\)\(..\)@0x\4\3\2\1@")
> -ivt_block_offset=$((${fit_block_offset} + ${fit_block_size} - 0x20))
> -csf_block_offset=$((${ivt_block_offset} + 0x20))
> -
> -echo "0xd1002041 ${ivt_block_base} 0x00000000 0x00000000 0x00000000 ${ivt_block_base} ${csf_block_base} 0x00000000" | xxd -r -p > ivt.bin
> -dd if=ivt.bin of=flash.bin bs=1 seek=${ivt_block_offset} conv=notrunc
> -```
> -
> -To generate CSF signature for the fitImage part of flash.bin container, use CST:
> -```
> -cst -i csf_fit.tmp -o csf_fit.bin
> -```
> -
> -Finally, patch the CSF signature into the fitImage right past the IVT:
> -```
> -dd if=csf_fit.bin of=flash.bin bs=1 seek=${csf_block_offset} conv=notrunc
> -```
> -
> -The entire script is available in doc/imx/habv4/csf_examples/mx8m/csf.sh
> -and can be used as follows to modify flash.bin to be signed
> -(adjust paths as needed):
> -```
> -export CST_DIR=/usr/src/cst-3.3.1/
> -export CSF_KEY=$CST_DIR/crts/CSF1_1_sha256_4096_65537_v3_usr_crt.pem
> -export IMG_KEY=$CST_DIR/crts/IMG1_1_sha256_4096_65537_v3_usr_crt.pem
> -export SRK_TABLE=$CST_DIR/crts/SRK_1_2_3_4_table.bin
> -export PATH=$CST_DIR/linux64/bin:$PATH
Hi Marek,
I thought you were going to leave the above env setting examples in
the documentation.
I suggest showing how to specify using env (by just leaving the above
in) as well as by copying them directly to the build directory if
wanted.. otherwise the documentation is lacking.
Best Regards,
Tim
> -/bin/sh doc/imx/habv4/csf_examples/mx8m/csf.sh
> -```
> +to authenticate, which keys to install, use and etc. The CSF is generated
> +using the CST Code Signing Tool based on input configuration file. This tool
> +input configuration file is generated using binman, and the tool is invoked
> +from binman as well.
> +
> +The SPL and fitImage sections of the generated image are signed separately.
> +The signing is activated by wrapping SPL and fitImage sections into nxp-imx8mcst
> +etype, which is done automatically in arch/arm/dts/imx8m{m,n,p,q}-u-boot.dtsi
> +in case CONFIG_IMX_HAB Kconfig symbol is enabled.
> +
> +The nxp-imx8mcst etype is configurable using either DT properties or environment
> +variables. The following DT properties and environment variables are supported.
> +Note that environment variables override DT properties.
> +
> ++--------------------+-----------+------------------------------------------------------------------+
> +| DT property | Variable | Description |
> ++====================+===========+==================================================================+
> +| nxp,loader-address | | SPL base address |
> ++--------------------+-----------+------------------------------------------------------------------+
> +| nxp,srk-table | SRK_TABLE | full path to SRK_1_2_3_4_table.bin |
> ++--------------------+-----------+------------------------------------------------------------------+
> +| nxp,csf-crt | CSF_KEY | full path to the CSF Key CSF1_1_sha256_4096_65537_v3_usr_crt.pem |
> ++--------------------+-----------+------------------------------------------------------------------+
> +| nxp,img-crt | IMG_KEY | full path to the IMG Key IMG1_1_sha256_4096_65537_v3_usr_crt.pem |
> ++--------------------+-----------+------------------------------------------------------------------+
> +
> +Build of flash.bin target then produces a signed flash.bin automatically.
>
> 1.4 Closing the device
> -----------------------
> --
> 2.43.0
>
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