sodium_crypto_secretbox_open

(PHP 7 >= 7.2.0, PHP 8)

sodium_crypto_secretbox_open — Authenticated shared-key decryption

Descrição

sodium_crypto_secretbox_open(string $ciphertext, string $nonce, #[\SensitiveParameter] string $key): string|false

Decrypt an encrypted message with a symmetric (shared) key.

Parâmetros

ciphertext

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

nonce

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()).

key

Encryption key (256-bit).

Valor Retornado

The decrypted string on success ou false em caso de falha.

Erros/Exceções

Exemplos

Example #1 sodium_crypto_secretbox_open() example

<?php
// 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 nonce and key are required to decrypt the $ciphertext
$plaintext = sodium_crypto_secretbox_open($ciphertext, $nonce, $key);
if ($plaintext !== false) {
    echo $plaintext . PHP_EOL;
}
?>

O exemplo acima produzirá:

message to be encrypted

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