This action performs symmetric encryption and decryption using AES-256-CBC,
supporting both operations with a provided key and IV.
It can be integrated into workflows to securely encrypt or decrypt data.
The key and IV are hashed using SHA-256 to ensure secure operations,
and the action performs encryption or decryption based on the specified operation.
## Usage
### Encrypt
```yaml
steps:
- name: Symmetric Encrypt Decrypt
uses: tmknom/symmetric-encrypt-decrypt-action@v0
with:
data: plaintext
operation: encrypt
```
### Decrypt
```yaml
steps:
- name: Symmetric Encrypt Decrypt
uses: tmknom/symmetric-encrypt-decrypt-action@v0
with:
data: ciphertext
operation: decrypt
```