import hashlib
import sys
from intelhex import IntelHex
from cryptography.hazmat.primitives import hashes
from cryptography.hazmat.primitives.asymmetric import padding, rsa
from cryptography.hazmat.backends import default_backend
from cryptography.hazmat.primitives import serialization
import os
import binascii

 
# Path to the hex file you want to load
file_path  = 'W:/xxx/xxx/xxx_input.hex'
privkey_path = 'W:/xxx/xxx/rivate_1024key.pem'
pubkey_path = 'W:/xxx/xxx/public_1024key.pem'
output_file = 'W:/xxx/xxx//Hash.txt'
outhex_file = 'W:/xxx/xxx/xxx_output.hex'

# Define the ranges() function
def ranges(addresses):
    start = addresses[0]
    end = addresses[0]
    for address in addresses[1:]:
        if address == end + 1:
            end = address
        else:
            yield start, end
            start = address
            end = address
    yield start, end

# Load the Intel Hex file
hex = IntelHex(file_path)

# Get the sorted list of addresses
addresses = hex.addresses()
addresses.sort()

# Iterate over address ranges and extract the data
data_list = list(ranges(addresses))
for start, end in data_list:
    size = end - start + 1
    data = list(hex.tobinarray(start=start, size=size)) 
    # Convert the data to hexadecimal format
    hex_data = ''.join(format(byte, '02x') for byte in data)  
    data_bytes = bytes.fromhex(hex_data)
    hasher = hashlib.sha256()
    hasher.update(data_bytes)
    hash_value = hasher.hexdigest()
    # Print the hash value in hexadecimal format
    print("SHA256 Hash Value:", hash_value)
   
    # Load the private key from file
try:
    with open(privkey_path, 'rb') as f:
        private_key = serialization.load_pem_private_key(
        f.read(),
        password=None,
        backend=default_backend()
    )
    print("private_key:", private_key)
    # If no exception occurred, the private key was loaded successfully
    print("Private key loaded successfully.")

    # Use the private key for signing or other operations
    
except Exception as e:
    print("Error loading private key:", e)

# Digest to be signed
# Convert the hash value to bytes

digest_bytes = bytes.fromhex(hash_value)

# Save the digest bytes to a file
with open(output_file, 'wb') as file:
    file.write(digest_bytes)
    print("Digest:", digest_bytes)


# Sign the digest with the private key
signature = private_key.sign(
    digest_bytes,
    padding.PKCS1v15(),  # Use PKCS1v15 padding scheme for RSA signatures
    hashes.SHA256()  # Use SHA256 hashing algorithm
)

# Convert the signature to hexadecimal format if needed
hex_signature = signature.hex()

# Print the hexadecimal signature
print("Hexadecimal signature:", hex_signature)