[PATCH RFC v2 05/11] ti: etype: x509: Add etype for x509 certificate for K3 devices
Neha Malcom Francis
n-francis at ti.com
Wed Jun 1 08:02:42 CEST 2022
Hi Roger,
On 31/05/22 14:50, Roger Quadros wrote:
>
>
> On 06/05/2022 07:37, Neha Malcom Francis wrote:
>> K3 devices x509 certificate added to certain binaries that allows ROM to
>
> what binaries?
>
>> validate the integrity of the image. Etype that generates an x509
>> certificate depending on boot flow added.
>
> Could you please explain in more detail as to what exactly is happening here.
>
> What do you mean by "depending on boot flow"?
>
I will reformat the commit messages accordingly.
>>
>> Signed-off-by: Neha Malcom Francis <n-francis at ti.com>
>> ---
>> tools/binman/entries.rst | 15 ++
>> tools/binman/etype/x509_cert.py | 248 ++++++++++++++++++++++++++++
>> tools/binman/ftest.py | 7 +
>> tools/binman/test/232_x509_cert.dts | 18 ++
>> tools/k3_gen_x509_cert.sh | 10 +-
>> 5 files changed, 293 insertions(+), 5 deletions(-)
>> create mode 100644 tools/binman/etype/x509_cert.py
>> create mode 100644 tools/binman/test/232_x509_cert.dts
>>
>> diff --git a/tools/binman/entries.rst b/tools/binman/entries.rst
>> index 0c6d82fce8..dfa281e49f 100644
>> --- a/tools/binman/entries.rst
>> +++ b/tools/binman/entries.rst
>> @@ -1890,6 +1890,21 @@ and kernel are genuine.
>>
>>
>>
>> +Entry: x509cert: x509 certificate for K3 devices
>> +------------------------------------------------
>> +
>
> x509 is a generic standard. Can this be made usable by other vendors as well or
> is it very specific to TI?
> If this is TI specific then I'd suggest a "ti-" prefix to the entry name.
>
>> +Properties / Entry arguments:
>> + - content: Phandle of binary to sign
>> + - output: Name of the final output file
>
> why do you need output property?
>
That is not required, I had later changed it to always using
certificate.bin. Will make the necessary changes.
>> + - key_file: File with key inside it. If not provided, script generates RSA degenerate key
>> + - core: Target core ID on which image would be running
>> + - load: Target load address of the binary in hex
>> +
>> + Output files:
>> + - certificate.bin: Signed certificate binary
>> +
>> +
>> +
>> Entry: x86-reset16: x86 16-bit reset code for U-Boot
>> ----------------------------------------------------
>>
>> diff --git a/tools/binman/etype/x509_cert.py b/tools/binman/etype/x509_cert.py
>> new file mode 100644
>> index 0000000000..0009973155
>> --- /dev/null
>> +++ b/tools/binman/etype/x509_cert.py
>> @@ -0,0 +1,248 @@
>> +# SPDX-License-Identifier: GPL-2.0+
>> +# Copyright (c) 2018 Google, Inc
>> +# Written by Simon Glass <sjg at chromium.org>
>> +#
>> +
>> +# Support for a x509 certificate for signing K3 devices
>> +
>> +import os
>> +from collections import OrderedDict
>> +from subprocess import Popen, PIPE
>> +from sys import stderr, stdout
>> +
>> +import asn1
>> +from Crypto.PublicKey import RSA
>> +from cryptography.hazmat.backends import default_backend
>> +from cryptography.hazmat.primitives import serialization
>> +
>> +from binman.etype.collection import Entry_collection
>> +from dtoc import fdt_util
>> +from patman import tools
>> +
>> +temp_x509 = "x509-temp.cert"
>> +cert = "certificate.bin"
>> +rand_key = "eckey.pem"
>> +bootcore_opts = 0
>> +bootcore = 0
>> +debug_type = 0
>> +
>> +
>> +class Entry_x509_cert(Entry_collection):
>> + """ An entry which contains a x509 certificate
>> +
>> + Properties / Entry arguments:
>> + - content: Phandle of binary to sign
>> + - key_file: File with key inside it. If not provided, script generates RSA degenerate key
>> + - core: Target core ID on which image would be running
>> + - load: Target load address of the binary in hex
>> +
>> + Output files:
>> + - certificate.bin: Signed certificate binary"""
>> +
>> + def __init__(self, section, etype, node):
>> + super().__init__(section, etype, node)
>> + self.key_file = fdt_util.GetString(self._node, 'key-file', "")
>> + self.core = fdt_util.GetInt(self._node, 'core', 0)
>> + self.load_addr = fdt_util.GetInt(self._node, 'load', 0x41c00000)
>> +
>> + def ReadNode(self):
>> + super().ReadNode()
>> + if self.key_file == "":
>> + self.degen_key = True
>> + else:
>> + self.degen_key = False
>> +
>> + def _CreateCertificate(self):
>> + """Create certificate for legacy boot flow"""
>> + if self.degen_key == True:
>> + gen_degen_key()
>> + self.key_file = rand_key
>> +
>> + sha_val = get_sha_val("intermediate-sysfw.bin")
>> + bin_size = get_file_size("intermediate-sysfw.bin")
>> + addr = "%08x" % self.load_addr
>> + if self.core == 0:
>> + cert_type = 2
>> + elif self.core == 16:
>> + cert_type = 1
>> + else:
>> + cert_type = 2
>> + debug_type = 0
>> +
>> + gen_template()
>> + gen_cert(bin_size, sha_val, cert_type, bootcore_opts,
>> + self.core, addr, debug_type, self.key_file)
>> +
>> + return tools.read_file("certificate.bin")
>> +
>> + def ObtainContents(self):
>> + self.image = self.GetContents(False)
>> + if self.image is None:
>> + return False
>> + f = open("intermediate-sysfw.bin", "wb")
>> + f.write(self.image)
>> + f.close()
>> + self.SetContents(self._CreateCertificate())
>> + return True
>> +
>> + def ProcessContents(self):
>> + data = self._CreateCertificate()
>> + return self.ProcessContentsUpdate(data)
>
> Why do you need _CreateCertificate() and ProcessContents()?
> Just have one ObtainContents() and try to get rid of all the intermediate files.
>
I used etype/vblock.py as a reference. I will clean up this etype further.
>> +
>> +
>> +def get_sha_val(binary_file):
>> + process = Popen(['openssl', 'dgst', '-sha512', '-hex',
>> + binary_file], stdout=PIPE, stderr=PIPE)
>> + stdout, stderr = process.communicate()
>> + sha_val = stdout.split()[1]
>> + return sha_val
>> +
>> +
>> +def get_file_size(binary_file):
>> + return os.path.getsize(binary_file)
>> +
>> +
>> +def gen_degen_template():
>> + with open("degen-template.txt", 'w+', encoding='utf-8') as f:
>> + degen_temp = """
>> +asn1=SEQUENCE:rsa_key
>> +
>> +[rsa_key]
>> +version=INTEGER:0
>> +modulus=INTEGER:0xDEGEN_MODULUS
>> +pubExp=INTEGER:1
>> +privExp=INTEGER:1
>> +p=INTEGER:0xDEGEN_P
>> +q=INTEGER:0xDEGEN_Q
>> +e1=INTEGER:1
>> +e2=INTEGER:1
>> +coeff=INTEGER:0xDEGEN_COEFF"""
>> + f.write(degen_temp)
>> +
>> +
>> +def gen_template():
>> + """Generate x509 Template"""
>> + with open("x509-template.txt", "w+", encoding='utf-8') as f:
>> + x509template = """
>> +[ req ]
>> +distinguished_name = req_distinguished_name
>> +x509_extensions = v3_ca
>> +prompt = no
>> +dirstring_type = nobmp
>> +
>> +[ req_distinguished_name ]
>> +C = US
>> +ST = TX
>> +L = Dallas
>> +O = Texas Instruments Incorporated
>> +OU = Processors
>> +CN = TI support
>> +emailAddress = support at ti.com
>> +
>> +[ v3_ca ]
>> +basicConstraints = CA:true
>> +1.3.6.1.4.1.294.1.1 = ASN1:SEQUENCE:boot_seq
>> +1.3.6.1.4.1.294.1.2 = ASN1:SEQUENCE:image_integrity
>> +1.3.6.1.4.1.294.1.3 = ASN1:SEQUENCE:swrv
>> +# 1.3.6.1.4.1.294.1.4 = ASN1:SEQUENCE:encryption
>> +1.3.6.1.4.1.294.1.8 = ASN1:SEQUENCE:debug
>> +
>> +[ boot_seq ]
>> +certType = INTEGER:TEST_CERT_TYPE
>> +bootCore = INTEGER:TEST_BOOT_CORE
>> +bootCoreOpts = INTEGER:TEST_BOOT_CORE_OPTS
>> +destAddr = FORMAT:HEX,OCT:TEST_BOOT_ADDR
>> +imageSize = INTEGER:TEST_IMAGE_LENGTH
>> +
>> +[ image_integrity ]
>> +shaType = OID:2.16.840.1.101.3.4.2.3
>> +shaValue = FORMAT:HEX,OCT:TEST_IMAGE_SHA_VAL
>> +
>> +[ swrv ]
>> +swrv = INTEGER:0
>> +
>> +# [ encryption ]
>> +# initalVector = FORMAT:HEX,OCT:TEST_IMAGE_ENC_IV
>> +# randomString = FORMAT:HEX,OCT:TEST_IMAGE_ENC_RS
>> +# iterationCnt = INTEGER:TEST_IMAGE_KEY_DERIVE_INDEX
>> +# salt = FORMAT:HEX,OCT:TEST_IMAGE_KEY_DERIVE_SALT
>> +
>> +[ debug ]
>> +debugUID = FORMAT:HEX,OCT:0000000000000000000000000000000000000000000000000000000000000000
>> +debugType = INTEGER:TEST_DEBUG_TYPE
>> +coreDbgEn = INTEGER:0
>> +coreDbgSecEn = INTEGER:0"""
>> + f.write(x509template)
>> +
>> +
>> +def parse_key(inp_key, section):
>> + parsed_key = ""
>> + section_true = False
>> + with open(inp_key, 'r') as file:
>> + for line in file:
>> + if section in line:
>> + section_true = True
>> + elif section_true:
>> + if " " not in line:
>> + break
>> + else:
>> + parsed_key += line.replace(":", "").replace(" ", "")
>> + return parsed_key.replace("\n", "")
>> +
>> +
>> +def gen_degen_key():
>> + """Generate a 4096 bit RSA key"""
>> + try:
>> + # generates 1024 bit PEM encoded RSA key in PKCS#1 format
>> + private_key = RSA.generate(1024)
>> + f = open('key.pem', 'wb')
>> + f.write(private_key.exportKey('PEM'))
>> + f.close()
>> + except:
>> + raise(Exception)
>> +
>> + try:
>> + process = Popen(['openssl', 'rsa', '-in', 'key.pem',
>> + '-text', '-out', 'key.txt'], stdout=PIPE, stderr=PIPE)
>> + stdout, stderr = process.communicate()
>> + except:
>> + raise(stderr)
>> +
>> + DEGEN_MODULUS = parse_key("key.txt", "modulus")
>> + DEGEN_P = parse_key("key.txt", "prime1")
>> + DEGEN_Q = parse_key("key.txt", "prime2")
>> + DEGEN_COEFF = parse_key("key.txt", "coefficient")
>> +
>> + gen_degen_template()
>> +
>> + with open("degen-template.txt", 'r') as file_input:
>> + with open("degenerateKey.txt", 'w') as file_output:
>> + for line in file_input:
>> + s = line.replace("DEGEN_MODULUS", DEGEN_MODULUS).replace(
>> + "DEGEN_P", DEGEN_P).replace("DEGEN_Q", DEGEN_Q).replace("DEGEN_COEFF", DEGEN_COEFF)
>> + file_output.write(s)
>> +
>> + try:
>> + process = Popen(['openssl', 'asn1parse', '-genconf', 'degenerateKey.txt',
>> + '-out', 'degenerateKey.der'], stdout=PIPE, stderr=PIPE)
>> + stdout, stderr = process.communicate()
>> + except:
>> + raise(stderr)
>> +
>> + try:
>> + process = Popen(['openssl', 'rsa', '-in', 'degenerateKey.der',
>> + '-inform', 'DER', '-outform', 'PEM', '-out', rand_key])
>> + stdout, stderr = process.communicate()
>> + except:
>> + raise(stderr)
>> +
>> +
>> +def gen_cert(bin_size, sha_val, cert_type, bootcore_opts, bootcore, addr, debug_type, key):
>> + with open(temp_x509, "w") as output_file:
>> + with open("x509-template.txt", "r") as input_file:
>> + for line in input_file:
>> + output_file.write(line.replace("TEST_IMAGE_LENGTH", str(bin_size)).replace("TEST_IMAGE_SHA_VAL", sha_val.decode("utf-8")).replace("TEST_CERT_TYPE", str(cert_type)).replace(
>> + "TEST_BOOT_CORE_OPTS", str(bootcore_opts)).replace("TEST_BOOT_CORE", str(bootcore)).replace("TEST_BOOT_ADDR", str(addr)).replace("TEST_DEBUG_TYPE", str(debug_type)))
>> + process = Popen(['openssl', 'req', '-new', '-x509', '-key', key, '-nodes', '-outform',
>> + 'DER', '-out', cert, '-config', temp_x509, '-sha512'], stdout=PIPE, stderr=PIPE)
>> + stdout, stderr = process.communicate()
>> diff --git a/tools/binman/ftest.py b/tools/binman/ftest.py
>> index 5ff294a386..d8ee592250 100644
>> --- a/tools/binman/ftest.py
>> +++ b/tools/binman/ftest.py
>> @@ -96,6 +96,7 @@ ENV_DATA = b'var1=1\nvar2="2"'
>> PRE_LOAD_MAGIC = b'UBSH'
>> PRE_LOAD_VERSION = 0x11223344.to_bytes(4, 'big')
>> PRE_LOAD_HDR_SIZE = 0x00001000.to_bytes(4, 'big')
>> +X509_DATA = b'filetobesigned'
>>
>> # Subdirectory of the input dir to use to put test FDTs
>> TEST_FDT_SUBDIR = 'fdts'
>> @@ -200,6 +201,7 @@ class TestFunctional(unittest.TestCase):
>> TestFunctional._MakeInputFile('fw_dynamic.bin', OPENSBI_DATA)
>> TestFunctional._MakeInputFile('sysfw.bin', TI_SYSFW_DATA)
>> TestFunctional._MakeInputFile('scp.bin', SCP_DATA)
>> + TestFunctional._MakeInputFile('tosign.bin', X509_DATA)
>>
>> # Add a few .dtb files for testing
>> TestFunctional._MakeInputFile('%s/test-fdt1.dtb' % TEST_FDT_SUBDIR,
>> @@ -5537,5 +5539,10 @@ fdt fdtmap Extract the devicetree blob from the fdtmap
>> data = self._DoReadFile('232_ti_sysfw.dts')
>> self.assertEqual(TI_SYSFW_DATA, data[:len(TI_SYSFW_DATA)])
>>
>> + def testX509Cert(self):
>> + """Test an image with the default x509 certificate header"""
>> + data = self._DoReadFile('232_x509_cert.dts')
>> + self.assertEqual(X509_DATA, data[938:938 + len(X509_DATA)])
>
> what is 938?
>
> Isn't it easier to just assert that _DoReadFile('232_x509_cert.dts') is greater than len(X509_DATA)?
>
>> +
>> if __name__ == "__main__":
>> unittest.main()
>> diff --git a/tools/binman/test/232_x509_cert.dts b/tools/binman/test/232_x509_cert.dts
>> new file mode 100644
>> index 0000000000..f768568ca7
>> --- /dev/null
>> +++ b/tools/binman/test/232_x509_cert.dts
>> @@ -0,0 +1,18 @@
>> +// SPDX-License-Identifier: GPL-2.0+
>> +
>> +/dts-v1/;
>> +
>> +/ {
>> + #address-cells = <1>;
>> + #size-cells = <1>;
>> +
>> + binman {
>> + x509-cert {
>> + content = <&image>;
>> + };
>> +
>> + image: blob-ext {
>> + filename = "tosign.bin";
>> + };
>> + };
>> +};
>> diff --git a/tools/k3_gen_x509_cert.sh b/tools/k3_gen_x509_cert.sh
>> index 298cec1313..b6ef5a2de3 100755
>> --- a/tools/k3_gen_x509_cert.sh
>> +++ b/tools/k3_gen_x509_cert.sh
>> @@ -109,7 +109,7 @@ gen_degen_key() {
>> openssl asn1parse -genconf degenerateKey.txt -out degenerateKey.der >>/dev/null 2>&1
>> openssl rsa -in degenerateKey.der -inform DER -outform PEM -out $RAND_KEY >>/dev/null 2>&1
>> KEY=$RAND_KEY
>> - rm key.pem key.txt degen-template.txt degenerateKey.txt degenerateKey.der
>> + #rm key.pem key.txt degen-template.txt degenerateKey.txt degenerateKey.der
>> }
>>
>> declare -A options_help
>> @@ -246,7 +246,7 @@ gen_cert
>> cat $CERT $BIN > $OUTPUT
>>
>> # Remove all intermediate files
>> -rm $TEMP_X509 $CERT x509-template.txt
>> -if [ "$KEY" == "$RAND_KEY" ]; then
>> - rm $RAND_KEY
>> -fi
>> +#rm $TEMP_X509 $CERT x509-template.txt
>> +#if [ "$KEY" == "$RAND_KEY" ]; then
>> +# rm $RAND_KEY
>> +#fi
>
> Why these changes?
> Maybe you should include them within
> "ifndef CONFIG_BINMAN ... endif" to avoid breaking platforms not using BINMAN.
>
> cheers,
> -roger
--
Thanking You
Neha Malcom Francis
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