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Authenticated Encryption with Associated Data: Decryption
Syntax Syntax
Description Description
Algorithm: XChaCha20-Poly1305
This mode uses a 64-bit random nonce with a 64-bit counter. IETF mode uses a 96-bit random nonce with a 32-bit counter.
Parameters Parameters
- $ciphertext
-
(Optional) Encrypted message (with Poly1305 MAC appended)
Default value: ''
- $assocData
-
(Optional) Authenticated Associated Data (unencrypted)
Default value: ''
- $nonce
-
(Optional) Number to be used only Once; must be 8 bytes
Default value: ''
- $key
-
(Optional) Encryption key
Default value: ''
- $dontFallback
-
(Optional) Don't fallback to ext/sodium
Default value: false
Return Return
(string|bool) The original plaintext message
Source Source
File: wp-includes/sodium_compat/src/Compat.php
public static function crypto_aead_xchacha20poly1305_ietf_decrypt(
$ciphertext = '',
$assocData = '',
$nonce = '',
$key = '',
$dontFallback = false
) {
/* Type checks: */
ParagonIE_Sodium_Core_Util::declareScalarType($ciphertext, 'string', 1);
ParagonIE_Sodium_Core_Util::declareScalarType($assocData, 'string', 2);
ParagonIE_Sodium_Core_Util::declareScalarType($nonce, 'string', 3);
ParagonIE_Sodium_Core_Util::declareScalarType($key, 'string', 4);
/* Input validation: */
if (ParagonIE_Sodium_Core_Util::strlen($nonce) !== self::CRYPTO_AEAD_XCHACHA20POLY1305_IETF_NPUBBYTES) {
throw new SodiumException('Nonce must be CRYPTO_AEAD_XCHACHA20POLY1305_IETF_NPUBBYTES long');
}
if (ParagonIE_Sodium_Core_Util::strlen($key) !== self::CRYPTO_AEAD_XCHACHA20POLY1305_IETF_KEYBYTES) {
throw new SodiumException('Key must be CRYPTO_AEAD_XCHACHA20POLY1305_IETF_KEYBYTES long');
}
if (ParagonIE_Sodium_Core_Util::strlen($ciphertext) < self::CRYPTO_AEAD_XCHACHA20POLY1305_IETF_ABYTES) {
throw new SodiumException('Message must be at least CRYPTO_AEAD_XCHACHA20POLY1305_IETF_ABYTES long');
}
if (self::useNewSodiumAPI() && !$dontFallback) {
if (is_callable('sodium_crypto_aead_xchacha20poly1305_ietf_decrypt')) {
return sodium_crypto_aead_xchacha20poly1305_ietf_decrypt(
$ciphertext,
$assocData,
$nonce,
$key
);
}
}
if (PHP_INT_SIZE === 4) {
return ParagonIE_Sodium_Crypto32::aead_xchacha20poly1305_ietf_decrypt(
$ciphertext,
$assocData,
$nonce,
$key
);
}
return ParagonIE_Sodium_Crypto::aead_xchacha20poly1305_ietf_decrypt(
$ciphertext,
$assocData,
$nonce,
$key
);
}