Encrypt/Decrypt URL PHP

Create PHP functions to encrypt and decrypt URLs using a specific encryption algorithm. Ensure that the functions are secure and can handle both encryption and decryption processes effectively.

# Requirements

– Use a secure algorithm such as AES for encryption and decryption.
– Utilize openssl functions available in PHP.
– Handle any errors or exceptions gracefully.
– Ensure URL data integrity during encryption/decryption processes.
– Consider using a secure key and initialization vector (IV) for AES.

# Steps

1. Define an encryption function that accepts URL, key, and IV as arguments.
2. Utilize openssl_encrypt with AES-256-CBC for encryption.
3. Encode the encrypted url in a URL-safe format (e.g., base64).
4. Define a decryption function that accepts the encrypted URL, key, and IV as arguments.
5. Decode the URL-safe format back to binary.
6. Utilize openssl_decrypt with AES-256-CBC to decrypt the data back to the original URL.
7. Handle any potential exceptions or errors.

# Output Format

Provide the PHP code with comments explaining each step.

# Example

Here is an example of encrypting and decrypting a URL in PHP:

<?php
function encryptUrl($url, $key, $iv) {
    $encrypted = openssl_encrypt($url, 'AES-256-CBC', $key, 0, $iv);
    return urlencode(base64_encode($encrypted));
}

function decryptUrl($encrypted, $key, $iv) {
    $decoded = base64_decode(urldecode($encrypted));
    return openssl_decrypt($decoded, 'AES-256-CBC', $key, 0, $iv);
}

// Usage
$key = 'your-encryption-key'; // ensure this is a secure key
$iv = 'your-init-vector';    // 16 bytes iv for AES-256-CBC

$originalUrl = 'https://www.example.com';
$encryptedUrl = encryptUrl($originalUrl, $key, $iv);
$decryptedUrl = decryptUrl($encryptedUrl, $key, $iv);

// Output
echo "Encrypted URL: $encryptedUrl\n";
echo "Decrypted URL: $decryptedUrl\n";
?>

# Notes

- Ensure the encryption key and initialization vector (IV) are securely stored and managed.
- The IV should be unique for each encryption to ensure security.
- Consider additional security best practices as applicable.