diff options
| -rw-r--r-- | encrypt.py | 31 |
1 files changed, 16 insertions, 15 deletions
@@ -7,34 +7,35 @@ import struct import subprocess import binascii -def encrypt_file(filename_in): +def encrypt_file(filename_in, chunk_size=1000000//16): file_id = secrets.token_urlsafe(22) auth_secret = secrets.token_bytes(16) key = secrets.token_bytes(16) - cipher_nonce = secrets.token_bytes(8) + data_nonce = secrets.token_bytes(8) token_cipher = AES.new(auth_secret, AES.MODE_GCM) ciphertext, token_tag = token_cipher.encrypt_and_digest(key) token = base64.b64encode(ciphertext) - with open(f'{file_id}.enc', 'wb') as fout: + with open(f'{file_id}.enc', 'wb') as fout, open(filename_in, 'rb') as fin: fout.write(token_cipher.nonce) # 16 bytes fout.write(token_tag) # 16 bytes fout.write(auth_secret) # 16 bytes - fout.write(cipher_nonce) # 8 bytes - fout.flush() + fout.write(data_nonce) # 8 bytes - subprocess.check_call(['openssl', 'enc', '-aes-128-ctr', - '-K', binascii.hexlify(key), - '-iv', binascii.hexlify(cipher_nonce + b'\0'*8), # nonce || counter format - '-in', filename_in, # no out: output defaults to stdout - ], stdout=fout.fileno()) + cipher = AES.new(key, AES.MODE_CTR, + initial_value=struct.pack('<Q', 0), nonce=data_nonce) - return file_id, token + block = fin.read(cipher.block_size*chunk_size) + while block: + data = cipher.encrypt(block) + fout.write(data) + block = fin.read(cipher.block_size*chunk_size) -def decrypt_generator(file_id, token, seek=0): + return file_id, token - with open(f'{file_id}.enc', 'rb', buffering=8192) as fin: +def decrypt_generator(file_id, token, seek=0, chunk_size=1000000//16): + with open(f'{file_id}.enc', 'rb') as fin: token_nonce = fin.read(16) token_tag = fin.read(16) auth_secret = fin.read(16) @@ -50,12 +51,12 @@ def decrypt_generator(file_id, token, seek=0): fin.seek(seek - seek % cipher.block_size, 1) offset = seek % cipher.block_size - block = fin.read(cipher.block_size) + block = fin.read(cipher.block_size*chunk_size) while block: data = cipher.decrypt(block) yield data[offset:] offset = 0 - block = fin.read(cipher.block_size) + block = fin.read(cipher.block_size*chunk_size) if __name__ == '__main__': import argparse |