Upload v1.0

encryption.py

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+from Crypto.Cipher import AES
+from Crypto.Protocol.KDF import scrypt
+from Crypto.Random import get_random_bytes
+from Crypto.Hash import SHA256
+
+def derive_key(password, salt):
+    """
+    Deriva una clave a partir de una contraseña y una sal.
+    """
+    if isinstance(salt, str):
+        salt = salt.encode("utf-8")
+    password = password.encode("utf-8")
+    key = scrypt(password, salt=salt, key_len=32, N=2**14, r=8, p=1)
+    return key
+
+def encrypt_text(password, text):
+    """
+    Cifra un texto usando una contraseña y devuelve el resultado cifrado y la sal utilizada.
+    """
+    salt = get_random_bytes(16)
+    key = derive_key(password, salt)
+    cipher = AES.new(key, AES.MODE_GCM)
+    text = text.encode("utf-8")
+    ciphertext, tag = cipher.encrypt_and_digest(text)
+    iv = cipher.nonce
+    result = salt + iv + len(tag).to_bytes(2, byteorder="big") + ciphertext + tag
+    return result
+
+def decrypt_text(password, data):
+    """
+    Descifra un texto cifrado usando una contraseña y devuelve el resultado descifrado.
+    """
+    salt = data[:16]
+    iv = data[16:32]
+    tag_size = int.from_bytes(data[32:34], byteorder="big")
+    ciphertext = data[34:-tag_size]
+    tag = data[-tag_size:]
+    key = derive_key(password, salt)
+    cipher = AES.new(key, AES.MODE_GCM, nonce=iv)
+    try:
+        plaintext = cipher.decrypt_and_verify(ciphertext, tag)
+    except ValueError:
+        raise Exception("Incorrect password or file has been modified.")
+    return plaintext.decode("utf-8")
+
+def encrypt_file(password, input_file, output_file):
+    """
+    Encripta un archivo usando una contraseña y escribe el resultado en otro archivo.
+    """
+    salt = get_random_bytes(16)
+    key = derive_key(password, salt)
+    cipher = AES.new(key, AES.MODE_GCM)
+    with open(input_file, 'rb') as f:
+        text = f.read()
+    ciphertext, tag = cipher.encrypt_and_digest(text)
+    iv = cipher.nonce
+    result = salt + iv + len(tag).to_bytes(2, byteorder="big") + ciphertext + tag
+    with open(output_file, "wb") as f:
+        f.write(result)
+
+def decrypt_file(password, input_file, output_file):
+    """
+    Descifra un archivo cifrado usando una contraseña y escribe el resultado en otro archivo.
+    """
+    with open(input_file, 'rb') as f:
+        data = f.read()
+    salt = data[:16]
+    iv = data[16:32]
+    tag_size = int.from_bytes(data[32:34], byteorder="big")
+    ciphertext = data[34:-tag_size]
+    tag = data[-tag_size:]
+    key = derive_key(password, salt)
+    cipher = AES.new(key, AES.MODE_GCM, nonce=iv)
+    try:
+        plaintext = cipher.decrypt_and_verify(ciphertext, tag)
+    except ValueError:
+        raise Exception("Incorrect password or file has been modified.")
+    with open(output_file, "wb") as f:
+        f.write(plaintext)
+
+def save_text(password, text, output_file):
+    """
+    Cifra un texto usando una contraseña y escribe el resultado cifrado en un archivo.
+    """
+    salt = get_random_bytes(16)
+    key = derive_key(password, salt)
+    cipher = AES.new(key, AES.MODE_GCM)
+    ciphertext, tag = cipher.encrypt_and_digest(text.encode('utf-8'))
+    iv = cipher.nonce
+    result = salt + iv + len(tag).to_bytes(2, byteorder="big") + ciphertext + tag
+    with open(output_file, "wb") as f:
+        f.write(result)