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Summery Summery
Calculate the shared secret between your secret key and your recipient’s public key.
Syntax Syntax
Description Description
Algorithm: X25519 (ECDH over Curve25519)
Parameters Parameters
- $secretKey
-
(Required)
- $publicKey
-
(Required)
Return Return
(string)
Source Source
File: wp-includes/sodium_compat/src/Compat.php
public static function crypto_scalarmult($secretKey, $publicKey)
{
/* Type checks: */
ParagonIE_Sodium_Core_Util::declareScalarType($secretKey, 'string', 1);
ParagonIE_Sodium_Core_Util::declareScalarType($publicKey, 'string', 2);
/* Input validation: */
if (ParagonIE_Sodium_Core_Util::strlen($secretKey) !== self::CRYPTO_BOX_SECRETKEYBYTES) {
throw new SodiumException('Argument 1 must be CRYPTO_BOX_SECRETKEYBYTES long.');
}
if (ParagonIE_Sodium_Core_Util::strlen($publicKey) !== self::CRYPTO_BOX_PUBLICKEYBYTES) {
throw new SodiumException('Argument 2 must be CRYPTO_BOX_PUBLICKEYBYTES long.');
}
if (self::useNewSodiumAPI()) {
return sodium_crypto_scalarmult($secretKey, $publicKey);
}
if (self::use_fallback('crypto_scalarmult')) {
return (string) call_user_func('\\Sodium\\crypto_scalarmult', $secretKey, $publicKey);
}
/* Output validation: Forbid all-zero keys */
if (ParagonIE_Sodium_Core_Util::hashEquals($secretKey, str_repeat("\0", self::CRYPTO_BOX_SECRETKEYBYTES))) {
throw new SodiumException('Zero secret key is not allowed');
}
if (ParagonIE_Sodium_Core_Util::hashEquals($publicKey, str_repeat("\0", self::CRYPTO_BOX_PUBLICKEYBYTES))) {
throw new SodiumException('Zero public key is not allowed');
}
if (PHP_INT_SIZE === 4) {
return ParagonIE_Sodium_Crypto32::scalarmult($secretKey, $publicKey);
}
return ParagonIE_Sodium_Crypto::scalarmult($secretKey, $publicKey);
}