1. Please install python "cryptography" library: pip install cryptography
2. Convert "text" to a signature.
import hashlib
from cryptography.hazmat.backends import default_backend from cryptography.hazmat.primitives import serialization from cryptography.hazmat.primitives.asymmetric import padding from cryptography.hazmat.primitives import hashes
# Read the content of the private key.
with open('mytproof.key', 'rb') as key_file:
   private_key = serialization.load_pem_private_key(
       key_file.read(),
       password=None,
       backend=default_backend()
   )
# Calculate the signature of the string.
string_to_sign = b'Your string 12345'
signature = private_key.sign(
   string_to_sign,
   padding.PKCS1v15(),
   hashes.SHA256()
)
# Display the obtained signature value (displayed in hex format)
print(signature.hex())
3. Convert "file" to a signature.
import hashlib
from cryptography.hazmat.backends import default_backend from cryptography.hazmat.primitives import serialization from cryptography.hazmat.primitives.asymmetric import padding from cryptography.hazmat.primitives import hashes
# Calculate the signature of the test.txt file.
with open('test.txt', 'rb') as file:
   file_content = file.read()
# Read the private key.
with open('mytproof.key', 'rb') as key_file:
   private_key = serialization.load_pem_private_key(
       key_file.read(),
       password=None,
       backend=default_backend()
   )
# Sign the file content using the private key.
signature = private_key.sign(
   file_content,
   padding.PKCS1v15(),
   hashes.SHA256()
)
# Display the obtained signature value (displayed in hex format)
print(signature.hex())