support of ec certificates added

This commit is contained in:
fdistorted 2020-10-16 13:46:05 +03:00
parent 92647716ca
commit 7e3c21c396

View file

@ -20,6 +20,7 @@ import socket
import textwrap
import math
import os
import cryptography
CERT_PATTERN = re.compile("^\-\-\-\-\-BEGIN CERTIFICATE\-\-\-\-\-[a-z,A-Z,0-9,\n,\/,+]+={0,2}\n\-\-\-\-\-END CERTIFICATE-\-\-\-\-", re.MULTILINE)
@ -32,6 +33,10 @@ DN_PRE = "TA_DN"
RSA_N_PRE = "TA_RSA_N"
# RSA public key exponent prefix
RSA_E_PRE = "TA_RSA_E"
# EC public key number prefix
EC_CURVE_PRE = "TA_EC_CURVE"
# EC curve type enum prefix
EC_CURVE_NAME_PRE = "BR_EC_"
# Template that defines the C header output format.
@ -81,7 +86,7 @@ static const {ray_type} {ray_name}[] = {{
{ray_data}
}};"""
# Template that defines a single root certificate entry in the BearSSL trust
# Template that defines a single root RSA certificate entry in the BearSSL trust
# anchor list
# This takes in a few named parameters:
# - ta_dn_name: The name of the static byte array containing the distunguished
@ -101,6 +106,25 @@ CROOTCA_TEMPLATE = """\
}}
}},"""
# Template that defines a single root EC certificate entry in the BearSSL trust
# anchor list
# This takes in a few named parameters:
# - ta_dn_name: The name of the static byte array containing the distunguished
# name of the certificate.
# - ec_number_name: Varible name of the static array containing ec public key
# - ec_curve_name: Varible name of the enum that describes curve type
CROOTCA_EC_TEMPLATE = """\
{{
{{ (unsigned char *){ta_dn_name}, sizeof {ta_dn_name} }},
BR_X509_TA_CA,
{{
BR_KEYTYPE_EC,
{{ .ec = {{{ec_curve_name}, (unsigned char *){ec_number_name}, sizeof {ec_number_name}}}
}}
}}
}},"""
# Template that defines a description of the certificate, so that the header
# file can be slightly more human readable
# This takes in a few named parameters:
@ -267,23 +291,40 @@ def x509_to_header(x509Certs, cert_var, cert_length_var, output_file, keep_dupes
# next, the RSA public numbers
pubkey = cert.get_pubkey()
numbers = pubkey.to_cryptography_key().public_numbers()
# starting with the modulous
n_bytes_str = bytes_to_c_data(numbers.n.to_bytes(pubkey.bits() // 8, byteorder="big"))
static_arrays.append(CRAY_TEMPLATE.format(
ray_type="unsigned char",
ray_name=RSA_N_PRE + str(cert_index),
ray_data=n_bytes_str))
# and then the exponent
e_bytes_str = bytes_to_c_data(numbers.e.to_bytes(math.ceil(numbers.e.bit_length() / 8), byteorder="big"))
static_arrays.append(CRAY_TEMPLATE.format(
ray_type="unsigned char",
ray_name=RSA_E_PRE + str(cert_index),
ray_data=e_bytes_str))
# format the root certificate entry
CAs.append(CROOTCA_TEMPLATE.format(
ta_dn_name=DN_PRE + str(cert_index),
rsa_number_name=RSA_N_PRE + str(cert_index),
rsa_exp_name=RSA_E_PRE + str(cert_index)))
if type(numbers) is cryptography.hazmat.primitives.asymmetric.rsa.RSAPublicNumbers:
# starting with the modulous
n_bytes_str = bytes_to_c_data(numbers.n.to_bytes(pubkey.bits() // 8, byteorder="big"))
static_arrays.append(CRAY_TEMPLATE.format(
ray_type="unsigned char",
ray_name=RSA_N_PRE + str(cert_index),
ray_data=n_bytes_str))
# and then the exponent
e_bytes_str = bytes_to_c_data(numbers.e.to_bytes(math.ceil(numbers.e.bit_length() / 8), byteorder="big"))
static_arrays.append(CRAY_TEMPLATE.format(
ray_type="unsigned char",
ray_name=RSA_E_PRE + str(cert_index),
ray_data=e_bytes_str))
# format the root certificate entry
CAs.append(CROOTCA_TEMPLATE.format(
ta_dn_name=DN_PRE + str(cert_index),
rsa_number_name=RSA_N_PRE + str(cert_index),
rsa_exp_name=RSA_E_PRE + str(cert_index)))
elif type(numbers) is cryptography.hazmat.primitives.asymmetric.ec.EllipticCurvePublicNumbers:
# starting with the modulous
curve_bytes = b'\x04' + numbers.x.to_bytes(pubkey.bits() // 8, byteorder="big") + numbers.y.to_bytes(
pubkey.bits() // 8, byteorder="big")
curve_str = bytes_to_c_data(curve_bytes)
curve_name = numbers.curve.name
static_arrays.append(CRAY_TEMPLATE.format(
ray_type="unsigned char",
ray_name=EC_CURVE_PRE + str(cert_index),
ray_data=curve_str))
# and then the exponent
CAs.append(CROOTCA_EC_TEMPLATE.format(
ta_dn_name=DN_PRE + str(cert_index),
ec_number_name=EC_CURVE_PRE + str(cert_index),
ec_curve_name=EC_CURVE_NAME_PRE + curve_name
))
# concatonate it all into the big header file template
# cert descriptions
cert_desc_out = '\n * \n'.join(cert_desc)