/**
* Derive a key pair for public key signatures from a password and salt
*
* @param string $password
* @param string $salt
* @param bool $legacy Use scrypt?
*
* @return SignatureKeyPair
* @throws CryptoException\InvalidSalt
*/
public static function deriveSignatureKeyPair(string $password, string $salt, bool $legacy = false) : SignatureKeyPair
{
if ($legacy) {
if (CryptoUtil::safeStrlen($salt) !== \Sodium\CRYPTO_PWHASH_SCRYPTSALSA208SHA256_SALTBYTES) {
throw new CryptoException\InvalidSalt('Expected ' . \Sodium\CRYPTO_PWHASH_SCRYPTSALSA208SHA256_SALTBYTES . ' bytes, got ' . CryptoUtil::safeStrlen($salt));
}
// Digital signature keypair
$seed = \Sodium\crypto_pwhash_scryptsalsa208sha256(\Sodium\CRYPTO_SIGN_SEEDBYTES, $password, $salt, \Sodium\CRYPTO_PWHASH_SCRYPTSALSA208SHA256_OPSLIMIT_INTERACTIVE, \Sodium\CRYPTO_PWHASH_SCRYPTSALSA208SHA256_MEMLIMIT_INTERACTIVE);
} else {
if (CryptoUtil::safeStrlen($salt) !== \Sodium\CRYPTO_PWHASH_SALTBYTES) {
throw new CryptoException\InvalidSalt('Expected ' . \Sodium\CRYPTO_PWHASH_SALTBYTES . ' bytes, got ' . CryptoUtil::safeStrlen($salt));
}
// Digital signature keypair
$seed = \Sodium\crypto_pwhash(\Sodium\CRYPTO_SIGN_SEEDBYTES, $password, $salt, \Sodium\CRYPTO_PWHASH_OPSLIMIT_INTERACTIVE, \Sodium\CRYPTO_PWHASH_MEMLIMIT_INTERACTIVE);
}
$keypair = \Sodium\crypto_sign_seed_keypair($seed);
$secret_key = \Sodium\crypto_sign_secretkey($keypair);
// Let's wipe our $kp variable
\Sodium\memzero($keypair);
return new SignatureKeyPair(new SignatureSecretKey($secret_key));
}
/**
* Derive a key pair for public key signatures from a password and salt
*
* @param HiddenString $password
* @param string $salt
* @param string $level Security level for KDF
*
* @return SignatureKeyPair
* @throws CryptoException\InvalidSalt
*/
public static function deriveSignatureKeyPair(HiddenString $password, string $salt, string $level = self::INTERACTIVE) : SignatureKeyPair
{
$kdfLimits = self::getSecurityLevels($level);
// VERSION 2+ (argon2)
if (Util::safeStrlen($salt) !== \Sodium\CRYPTO_PWHASH_SALTBYTES) {
throw new CryptoException\InvalidSalt('Expected ' . \Sodium\CRYPTO_PWHASH_SALTBYTES . ' bytes, got ' . Util::safeStrlen($salt));
}
// Digital signature keypair
$seed = \Sodium\crypto_pwhash(\Sodium\CRYPTO_SIGN_SEEDBYTES, $password->getString(), $salt, $kdfLimits[0], $kdfLimits[1]);
$keyPair = \Sodium\crypto_sign_seed_keypair($seed);
$secretKey = \Sodium\crypto_sign_secretkey($keyPair);
// Let's wipe our $kp variable
\Sodium\memzero($keyPair);
return new SignatureKeyPair(new SignatureSecretKey(new HiddenString($secretKey)));
}
