[PATCH v3 3/3] tools: binman: Add tests for FIT with data encrypted by mkimage

Simon Glass sjg at chromium.org
Wed Nov 20 14:35:49 CET 2024


On Wed, 20 Nov 2024 at 03:09, Paul HENRYS
<paul.henrys_ext at softathome.com> wrote:
>
> Test the property 'fit,keys-directory' which, when a cipher node is
> present, encrypts the data stored in the FIT.
>
> Signed-off-by: Paul HENRYS <paul.henrys_ext at softathome.com>
> ---
> Changes for v3:
>  - Write out IV in full for clarity as requested
>  - Do not replace the null byte but use fdt_util.GetString() instead
>  - Adapt the tests for the FIT data encryption to create a file with the content
>    of the AES key in the working directory and pass the path to binman
>
>  tools/binman/ftest.py                         |  45 +++++++++++++++
>  tools/binman/test/343_fit_encrypt_data.dts    |  53 ++++++++++++++++++
>  .../test/344_fit_encrypt_data_no_key.dts      |  53 ++++++++++++++++++
>  tools/binman/test/aes256.bin                  | Bin 0 -> 32 bytes
>  4 files changed, 151 insertions(+)
>  create mode 100644 tools/binman/test/343_fit_encrypt_data.dts
>  create mode 100644 tools/binman/test/344_fit_encrypt_data_no_key.dts
>  create mode 100644 tools/binman/test/aes256.bin

Reviewed-by: Simon Glass <sjg at chromium.org>

>
> diff --git a/tools/binman/ftest.py b/tools/binman/ftest.py
> index adab65e579..b19b0cc5b3 100644
> --- a/tools/binman/ftest.py
> +++ b/tools/binman/ftest.py
> @@ -7900,5 +7900,50 @@ fdt         fdtmap                Extract the devicetree blob from the fdtmap
>              extra_indirs=[test_subdir])[0]
>
>
> +    def testSimpleFitEncryptedData(self):
> +        """Test an image with a FIT containing data to be encrypted"""
> +        data = tools.read_file(self.TestFile("aes256.bin"))
> +        self._MakeInputFile("keys/aes256.bin", data)
> +
> +        keys_subdir = os.path.join(self._indir, "keys")
> +        data = self._DoReadFileDtb(
> +            '343_fit_encrypt_data.dts',
> +            extra_indirs=[keys_subdir])[0]
> +
> +        fit = fdt.Fdt.FromData(data)
> +        fit.Scan()
> +
> +        # Extract the encrypted data and the Initialization Vector from the FIT
> +        node = fit.GetNode('/images/u-boot')
> +        subnode = fit.GetNode('/images/u-boot/cipher')
> +        data_size_unciphered = int.from_bytes(fit.GetProps(node)['data-size-unciphered'].bytes,
> +                                              byteorder='big')
> +        self.assertEqual(data_size_unciphered, len(U_BOOT_NODTB_DATA))
> +
> +        # Retrieve the key name from the FIT removing any null byte
> +        key_name = fit.GetProps(subnode)['key-name-hint'].bytes.replace(b'\x00', b'')
> +        with open(self.TestFile(key_name.decode('ascii') + '.bin'), 'rb') as file:
> +            key = file.read()
> +        iv = fit.GetProps(subnode)['iv'].bytes.hex()
> +        enc_data = fit.GetProps(node)['data'].bytes
> +        outdir = tools.get_output_dir()
> +        enc_data_file = os.path.join(outdir, 'encrypted_data.bin')
> +        tools.write_file(enc_data_file, enc_data)
> +        data_file = os.path.join(outdir, 'data.bin')
> +
> +        # Decrypt the encrypted data from the FIT and compare the data
> +        tools.run('openssl', 'enc', '-aes-256-cbc', '-nosalt', '-d', '-in',
> +                  enc_data_file, '-out', data_file, '-K', key.hex(), '-iv', iv)
> +        with open(data_file, 'r') as file:
> +            dec_data = file.read()
> +        self.assertEqual(U_BOOT_NODTB_DATA, dec_data.encode('ascii'))
> +
> +    def testSimpleFitEncryptedDataMissingKey(self):
> +        """Test an image with a FIT containing data to be encrypted but with a missing key"""
> +        with self.assertRaises(ValueError) as e:
> +            self._DoReadFile('344_fit_encrypt_data_no_key.dts')
> +
> +        self.assertIn("Filename 'aes256.bin' not found in input path", str(e.exception))
> +
>  if __name__ == "__main__":
>      unittest.main()
> diff --git a/tools/binman/test/343_fit_encrypt_data.dts b/tools/binman/test/343_fit_encrypt_data.dts
> new file mode 100644
> index 0000000000..90e504979b
> --- /dev/null
> +++ b/tools/binman/test/343_fit_encrypt_data.dts
> @@ -0,0 +1,53 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +
> +/dts-v1/;
> +
> +/ {
> +       #address-cells = <1>;
> +       #size-cells = <1>;
> +
> +       binman {
> +               fit {
> +                       fit,keys-directory;
> +                       description = "Test a FIT with encrypted data";
> +                       #address-cells = <1>;
> +
> +                       images {
> +                               u-boot {
> +                                       description = "U-Boot";
> +                                       type = "firmware";
> +                                       arch = "arm64";
> +                                       os = "U-Boot";
> +                                       compression = "none";
> +                                       load = <00000000>;
> +                                       entry = <00000000>;
> +                                       cipher {
> +                                               algo = "aes256";
> +                                               key-name-hint = "aes256";
> +                                       };
> +                                       u-boot-nodtb {
> +                                       };
> +                               };
> +                               fdt-1 {
> +                                       description = "Flattened Device Tree blob";
> +                                       type = "flat_dt";
> +                                       arch = "arm64";
> +                                       compression = "none";
> +                                       cipher {
> +                                               algo = "aes256";
> +                                               key-name-hint = "aes256";
> +                                       };
> +                               };
> +                       };
> +
> +                       configurations {
> +                               default = "conf-1";
> +                               conf-1 {
> +                                       description = "Boot U-Boot with FDT blob";
> +                                       firmware = "u-boot";
> +                                       fdt = "fdt-1";
> +                               };
> +                       };
> +               };
> +       };
> +};
> diff --git a/tools/binman/test/344_fit_encrypt_data_no_key.dts b/tools/binman/test/344_fit_encrypt_data_no_key.dts
> new file mode 100644
> index 0000000000..90e504979b
> --- /dev/null
> +++ b/tools/binman/test/344_fit_encrypt_data_no_key.dts
> @@ -0,0 +1,53 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +
> +/dts-v1/;
> +
> +/ {
> +       #address-cells = <1>;
> +       #size-cells = <1>;
> +
> +       binman {
> +               fit {
> +                       fit,keys-directory;
> +                       description = "Test a FIT with encrypted data";
> +                       #address-cells = <1>;
> +
> +                       images {
> +                               u-boot {
> +                                       description = "U-Boot";
> +                                       type = "firmware";
> +                                       arch = "arm64";
> +                                       os = "U-Boot";
> +                                       compression = "none";
> +                                       load = <00000000>;
> +                                       entry = <00000000>;
> +                                       cipher {
> +                                               algo = "aes256";
> +                                               key-name-hint = "aes256";
> +                                       };
> +                                       u-boot-nodtb {
> +                                       };
> +                               };
> +                               fdt-1 {
> +                                       description = "Flattened Device Tree blob";
> +                                       type = "flat_dt";
> +                                       arch = "arm64";
> +                                       compression = "none";
> +                                       cipher {
> +                                               algo = "aes256";
> +                                               key-name-hint = "aes256";
> +                                       };
> +                               };
> +                       };
> +
> +                       configurations {
> +                               default = "conf-1";
> +                               conf-1 {
> +                                       description = "Boot U-Boot with FDT blob";
> +                                       firmware = "u-boot";
> +                                       fdt = "fdt-1";
> +                               };
> +                       };
> +               };
> +       };
> +};
> diff --git a/tools/binman/test/aes256.bin b/tools/binman/test/aes256.bin
> new file mode 100644
> index 0000000000000000000000000000000000000000..09b8bf6254ada5c084039f32916bc7d30233bb2c
> GIT binary patch
> literal 32
> ncmXpsGBz<aGq<obNK8sjNli=7$jr*l$<50zC at d;2DJ=s4pC}7U
>
> literal 0
> HcmV?d00001
>
> --
> 2.43.0

[..]


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