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sodium_crypto_secretbox

(PHP 7 >= 7.2.0, PHP 8)

sodium_crypto_secretbox — Authenticated shared-key encryption

Descrição

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

Encrypt a message with a symmetric (shared) key.

Parâmetros

message: The plaintext message to encrypt.
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

Returns the encrypted string.

Erros/Exceções

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.

Exemplos

Exemplo #1 sodium_crypto_secretbox() example

<?php
// 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 nonce and key are required to decrypt the $ciphertext
var_dump(sodium_crypto_secretbox_open($ciphertext, $nonce, $key));
?>

O exemplo acima produzirá algo semelhante a:

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

Veja Também

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

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User Contributed Notes 1 note

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celso fontes ¶

4 years ago


An example to how encrypt or decrypt using sodium:

<?php

$key = random_bytes(SODIUM_CRYPTO_SECRETBOX_KEYBYTES);

$nonce = random_bytes(SODIUM_CRYPTO_SECRETBOX_NONCEBYTES);
$ciphertext = sodium_crypto_secretbox("Hello World !", $nonce, $key);

$plaintext = sodium_crypto_secretbox_open($ciphertext, $nonce, $key);
if ($plaintext === false) {
    throw new Exception("Bad ciphertext");
}

echo $plaintext;

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