bcb-0026

# BigCodeBench/26

Implement a file **`solution.py`** that completes the function below. Keep the given name and signature; define `task_func` at module level.

Allowed libraries: `base64`, `cryptography`.

```python
import base64
from cryptography.fernet import Fernet

def task_func(message, encryption_key):
    """
    Encrypts a message with a symmetric encryption key using Fernet encryption, and then encode the 
    encrypted message using base64.

    Parameters:
    message (str): The message to be encrypted and encoded.
    encryption_key (str): The key used for symmetric encryption. It should be a string, which will 
                          be encoded to bytes, then URL-safe base64 encoded to conform to the requirements 
                          for Fernet (32 bytes after encoding).

    Returns:
    str: The base64 encoded encrypted message. The message is first encrypted using Fernet encryption, 
         then the result is base64 encoded.

    Requirements:
    - base64
    - cryptography.fernet

    Example:
    >>> encrypted_message = task_func('Hello, World!', '01234567890123456789012345678901')
    >>> isinstance(encrypted_message, str)
    True
    """
```

<!-- imported from BigCodeBench (BigCodeBench/26) -->

# Auto-generated from BigCodeBench BigCodeBench/26. Do not edit by hand.
import pathlib as _pathlib
exec(_pathlib.Path(__file__).with_name("solution.py").read_text(), globals())

import unittest
import base64
from cryptography.fernet import Fernet
class TestCases(unittest.TestCase):
    def test_case_1(self):
        # Test with a basic message and a valid encryption key.
        result = task_func('Hello, World!', '01234567890123456789012345678901')
        self.assertIsInstance(result, str)
        self.assertNotEqual(result, 'Hello, World!')
    def test_case_2(self):
        # Test with an empty message and a valid encryption key.
        result = task_func('', '01234567890123456789012345678901')
        self.assertIsInstance(result, str)
        self.assertNotEqual(result, '')
    def test_case_3(self):
        # Test with a numeric message and a valid encryption key.
        result = task_func('1234567890', '01234567890123456789012345678901')
        self.assertIsInstance(result, str)
        self.assertNotEqual(result, '1234567890')
    def test_case_4(self):
        # Test with a long message and a valid encryption key.
        long_message = 'A' * 500
        result = task_func(long_message, '01234567890123456789012345678901')
        self.assertIsInstance(result, str)
        self.assertNotEqual(result, long_message)
    def test_case_5(self):
        # Test with a basic message and an incorrectly formatted encryption key.
        with self.assertRaises(ValueError):
            task_func('Hello, World!', '0123456789')
    def test_case_6(self):
        # Test with a non-base64 but correct length key.
        with self.assertRaises(Exception):
            task_func('Hello, World!', '01234567890123456789012345678901'*2)  # Not base64-encoded

You are an expert programmer. Solve the task exactly as specified. Output your solution as fenced code blocks using the required file name(s) and the exact function/type signatures requested. Prefer correctness; do not include prose outside code unless asked.

```python
import base64
from cryptography.fernet import Fernet

def task_func(message, encryption_key):
    """
    Encrypts a message with a symmetric encryption key using Fernet encryption, and then encode the
    encrypted message using base64.

    Parameters:
    message (str): The message to be encrypted and encoded.
    encryption_key (str): The key used for symmetric encryption. It should be a string, which will
                          be encoded to bytes, then URL-safe base64 encoded to conform to the requirements
                          for Fernet (32 bytes after encoding).

    Returns:
    str: The base64 encoded encrypted message. The message is first encrypted using Fernet encryption,
         then the result is base64 encoded.
    """
    # Create a Fernet instance using the provided encryption key
    fernet = Fernet(encryption_key)

    # Encrypt the message
    encrypted_message = fernet.encrypt(message.encode())

    # Base64 encode the encrypted message
    base64_encoded = base64.b64encode(encrypted_message).decode()

    return base64_encoded
```

[
  {
    "total": 6,
    "answer": "```python\nimport base64\nfrom cryptography.fernet import Fernet\n\ndef task_func(message, encryption_key):\n    \"\"\"\n    Encrypts a message with a symmetric encryption key using Fernet encryption, and then encode the\n    encrypted message using base64.\n\n    Parameters:\n    message (str): The message to be encrypted and encoded.\n    encryption_key (str): The key used for symmetric encryption. It should be a string, which will\n                          be encoded to bytes, then URL-safe base64 encoded to conform to the requirements\n                          for Fernet (32 bytes after encoding).\n\n    Returns:\n    str: The base64 encoded encrypted message. The message is first encrypted using Fernet encryption,\n         then the result is base64 encoded.\n    \"\"\"\n    # Create a Fernet instance using the provided encryption key\n    fernet = Fernet(encryption_key)\n\n    # Encrypt the message\n    encrypted_message = fernet.encrypt(message.encode())\n\n    # Base64 encode the encrypted message\n    base64_encoded = base64.b64encode(encrypted_message).decode()\n\n    return base64_encoded\n```",
    "passed": 2,
    "test_error": "5'\nbackend = None\n\n    def __init__(\n        self,\n        key: typing.Union[bytes, str],\n        backend: typing.Any = None,\n    ):\n        try:\n            key = base64.urlsafe_b64decode(key)\n        except binascii.Error as exc:\n            raise ValueError(\n                \"Fernet key must be 32 url-safe base64-encoded bytes.\"\n            ) from exc\n        if len(key) != 32:\n>           raise ValueError(\n                \"Fernet key must be 32 url-safe base64-encoded bytes.\"\n            )\nE           ValueError: Fernet key must be 32 url-safe base64-encoded bytes.\n\n/home/psc/miniconda3/envs/peakstone-bcb/lib/python3.10/site-packages/cryptography/fernet.py:39: ValueError\n____________________________ TestCases.test_case_4 _____________________________\n\nself = <test_bcb_0026.TestCases testMethod=test_case_4>\n\n    def test_case_4(self):\n        # Test with a long message and a valid encryption key.\n        long_message = 'A' * 500\n>       result = task_func(long_message, '01234567890123456789012345678901')\n\ntest_bcb_0026.py:27: \n_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ \n<string>:20: in task_func\n    ???\n_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ \n\nself = <cryptography.fernet.Fernet object at 0x75b301838820>\nkey = b'\\xd3]\\xb7\\xe3\\x9e\\xbb\\xf3\\xdd5\\xdb~9\\xeb\\xbf=\\xd3]\\xb7\\xe3\\x9e\\xbb\\xf3\\xdd5'\nbackend = None\n\n    def __init__(\n        self,\n        key: typing.Union[bytes, str],\n        backend: typing.Any = None,\n    ):\n        try:\n            key = base64.urlsafe_b64decode(key)\n        except binascii.Error as exc:\n            raise ValueError(\n                \"Fernet key must be 32 url-safe base64-encoded bytes.\"\n            ) from exc\n        if len(key) != 32:\n>           raise ValueError(\n                \"Fernet key must be 32 url-safe base64-encoded bytes.\"\n            )\nE           ValueError: Fernet key must be 32 url-safe base64-encoded bytes.\n\n/home/psc/miniconda3/envs/peakstone-bcb/lib/python3.10/site-packages/cryptography/fernet.py:39: ValueError\n=========================== short test summary info ============================\nFAILED test_bcb_0026.py::TestCases::test_case_1 - ValueError: Fernet key must...\nFAILED test_bcb_0026.py::TestCases::test_case_2 - ValueError: Fernet key must...\nFAILED test_bcb_0026.py::TestCases::test_case_3 - ValueError: Fernet key must...\nFAILED test_bcb_0026.py::TestCases::test_case_4 - ValueError: Fernet key must...\n4 failed, 2 passed in 0.07s"
  },
  {
    "total": 6,
    "answer": "```python\nimport base64\nfrom cryptography.fernet import Fernet\n\ndef task_func(message, encryption_key):\n    \"\"\"\n    Encrypts a message with a symmetric encryption key using Fernet encryption, and then encode the\n    encrypted message using base64.\n\n    Parameters:\n    message (str): The message to be encrypted and encoded.\n    encryption_key (str): The key used for symmetric encryption. It should be a string, which will\n                          be encoded to bytes, then URL-safe base64 encoded to conform to the requirements\n                          for Fernet (32 bytes after encoding).\n\n    Returns:\n    str: The base64 encoded encrypted message. The message is first encrypted using Fernet encryption,\n         then the result is base64 encoded.\n    \"\"\"\n    # Ensure the encryption_key is properly formatted as a Fernet key\n    # Fernet keys must be 32 url-safe base64-encoded bytes\n    if isinstance(encryption_key, str):\n        encryption_key = encryption_key.encode()\n\n    # Create a Fernet instance using the provided encryption key\n    fernet = Fernet(base64.urlsafe_b64encode(encryption_key))\n\n    # Encrypt the message\n    encrypted_message = fernet.encrypt(message.encode())\n\n    # Base64 encode the encrypted message\n    base64_encoded = base64.b64encode(encrypted_message).decode()\n\n    return base64_encoded\n```",
    "passed": 6,
    "test_error": ""
  }
]