ParagonIE_Sodium_Compat::crypto_kdf_derive_from_key( int $subkey_len, int $subkey_id, string $context, string $key ): string

1935    public static function crypto_kdf_derive_from_key(1936        $subkey_len,1937        $subkey_id,1938        $context,1939        #[\SensitiveParameter]1940        $key1941    ) {1942        ParagonIE_Sodium_Core_Util::declareScalarType($subkey_len, 'int', 1);1943        ParagonIE_Sodium_Core_Util::declareScalarType($subkey_id, 'int', 2);1944        ParagonIE_Sodium_Core_Util::declareScalarType($context, 'string', 3);1945        ParagonIE_Sodium_Core_Util::declareScalarType($key, 'string', 4);1946        $subkey_id = (int) $subkey_id;1947        $subkey_len = (int) $subkey_len;1948        $context = (string) $context;1949        $key = (string) $key;1950 1951        if ($subkey_len < self::CRYPTO_KDF_BYTES_MIN) {1952            throw new SodiumException('subkey cannot be smaller than SODIUM_CRYPTO_KDF_BYTES_MIN');1953        }1954        if ($subkey_len > self::CRYPTO_KDF_BYTES_MAX) {1955            throw new SodiumException('subkey cannot be larger than SODIUM_CRYPTO_KDF_BYTES_MAX');1956        }1957        if ($subkey_id < 0) {1958            throw new SodiumException('subkey_id cannot be negative');1959        }1960        if (ParagonIE_Sodium_Core_Util::strlen($context) !== self::CRYPTO_KDF_CONTEXTBYTES) {1961            throw new SodiumException('context should be SODIUM_CRYPTO_KDF_CONTEXTBYTES bytes');1962        }1963        if (ParagonIE_Sodium_Core_Util::strlen($key) !== self::CRYPTO_KDF_KEYBYTES) {1964            throw new SodiumException('key should be SODIUM_CRYPTO_KDF_KEYBYTES bytes');1965        }1966 1967        $salt = ParagonIE_Sodium_Core_Util::store64_le($subkey_id);1968        $state = self::crypto_generichash_init_salt_personal(1969            $key,1970            $subkey_len,1971            $salt,1972            $context1973        );1974        return self::crypto_generichash_final($state, $subkey_len);1975    }