Hướng dẫn dùng secretbox trong PHP

(PHP 7 >= 7.2.0, PHP 8)

sodium_crypto_secretbox — Authenticated shared-key encryption

Description

sodium_crypto_secretbox(string $message, string $nonce, string $key): string

Parameters

The plaintext message to encrypt.

A number that must be only used once, per message. 24 bytes long. This is a large enough bound to generate randomly (i.e. random_bytes()).

Encryption key (256-bit).

Return Values

Returns the encrypted string.

Errors/Exceptions

• If nonce has a length of bytes different than SODIUM_CRYPTO_SECRETBOX_NONCEBYTES (24 bytes), a SodiumException will be thrown.
• If key has a length of bytes different than SODIUM_CRYPTO_SECRETBOX_KEYBYTES (32 bytes), a SodiumException will be thrown.
• Throws a SodiumException on failure.

Examples

Example #1 sodium_crypto_secretbox() example

// The $key must be kept confidential
$key = sodium_crypto_secretbox_keygen();
// Do not reuse $nonce with the same key
$nonce = random_bytes(SODIUM_CRYPTO_SECRETBOX_NONCEBYTES);
$plaintext = "message to be encrypted";
$ciphertext = sodium_crypto_secretbox($plaintext, $nonce, $key);var_dump(bin2hex($ciphertext));
// The same nouce and key are required to decrypt the $ciphertext
var_dump(sodium_crypto_secretbox_open($ciphertext, $nonce, $key));
?>

The above example will output something similar to:

string(78) "3a1fa3e9f7b72ef8be51d40abf8e296c6899c185d07b18b4c93e7f26aa776d24c50852cd6b1076"
string(23) "message to be encrypted"

See Also

• sodium_crypto_secretbox_open() - Authenticated shared-key decryption
• sodium_crypto_secretbox_keygen() - Generate random key for sodium_crypto_secretbox
• random_bytes() - Generates cryptographically secure pseudo-random bytes

celso fontes ¶

2 years ago

An example to how encrypt or decrypt using sodium:

$key

(PHP 7 >= 7.2.0, PHP 8)

sodium_crypto_secretbox_open — Authenticated shared-key decryption

Description

sodium_crypto_secretbox_open(string $ciphertext, string $nonce, string $key): string|false

Parameters

Must be in the format provided by sodium_crypto_secretbox() (ciphertext and tag, concatenated).

A number that must be only used once, per message. 24 bytes long. This is a large enough bound to generate randomly (i.e. random_bytes()).

Encryption key (256-bit).

Return Values

The decrypted string on success or false on failure.

Errors/Exceptions

• If nonce has a length of bytes different than SODIUM_CRYPTO_SECRETBOX_NONCEBYTES (24 bytes), a SodiumException will be thrown.
• If key has a length of bytes different than SODIUM_CRYPTO_SECRETBOX_KEYBYTES (32 bytes), a SodiumException will be thrown.

Examples

Example #1 sodium_crypto_secretbox_open() example

// The $key must be kept confidential
$key = random_bytes(SODIUM_CRYPTO_SECRETBOX_KEYBYTES);
// Do not reuse $nonce with the same key
$nonce = random_bytes(SODIUM_CRYPTO_SECRETBOX_NONCEBYTES);
$ciphertext = sodium_crypto_secretbox('message to be encrypted', $nonce, $key);// The same nouce and key are required to decrypt the $ciphertext
$plaintext = sodium_crypto_secretbox_open($ciphertext, $nonce, $key);
if ($plaintext !== false) {
    echo $plaintext . PHP_EOL;
}
?>

The above example will output:

See Also

• sodium_crypto_secretbox() - Authenticated shared-key encryption
• sodium_crypto_secretbox_keygen() - Generate random key for sodium_crypto_secretbox
• random_bytes() - Generates cryptographically secure pseudo-random bytes

khalyomede at gmail dot com ¶

3 years ago

This method will return a string, or false if the data failed to be decrypted.

$key = 'secret';
$data = 'binarydata';
$nonce = random_bytes(SODIUM_CRYPT_SECRETBOX_NONCEBYTES);

$decrypted = sodium_crypto_secretbox_open($data, $nonce, $key);

if ($decrypted === false) {
  throw new Exception('failed to decrypt data');
}