/**
 * @license
 * Copyright 2020 Google LLC
 * SPDX-License-Identifier: Apache-2.0
 */
/**
 * Does near constant time byte array comparison.
 * @param ba1 The first bytearray to check.
 * @param ba2 The second bytearray to check.
 * @return If the array are equal.
 */
export declare function isEqual(ba1: Uint8Array, ba2: Uint8Array): boolean;
/**
 * Returns a new array that is the result of joining the arguments.
 */
export declare function concat(...var_args: Uint8Array[]): Uint8Array;
/**
 * Converts a non-negative integer number to a 64-bit big-endian byte array.
 * @param value The number to convert.
 * @return The number as a big-endian byte array.
 * @throws {InvalidArgumentsException}
 * @static
 */
export declare function fromNumber(value: number): Uint8Array;
/**
 * Converts the hex string to a byte array.
 *
 * @param hex the input
 * @return the byte array output
 * @throws {!InvalidArgumentsException}
 * @static
 */
export declare function fromHex(hex: string): Uint8Array;
/**
 * Converts a byte array to hex.
 *
 * @param bytes the byte array input
 * @return hex the output
 * @static
 */
export declare function toHex(bytes: Uint8Array): string;
/**
 * Converts the Base64 string to a byte array.
 *
 * @param encoded the base64 string
 * @param opt_webSafe True indicates we should use the alternative
 *     alphabet, which does not require escaping for use in URLs.
 * @return the byte array output
 * @static
 */
export declare function fromBase64(encoded: string, opt_webSafe?: boolean): Uint8Array;
/**
 * Base64 encode a byte array.
 *
 * @param bytes the byte array input
 * @param opt_webSafe True indicates we should use the alternative
 *     alphabet, which does not require escaping for use in URLs.
 * @return base64 output
 * @static
 */
export declare function toBase64(bytes: Uint8Array, opt_webSafe?: boolean): string;
/**
 * Converts a byte string to a byte array. Only support ASCII and Latin-1
 * strings, does not support multi-byte characters.
 *
 * @param str the input
 * @return the byte array output
 * @static
 */
export declare function fromByteString(str: string): Uint8Array;
/**
 * Turns a byte array into the string given by the concatenation of the
 * characters to which the numbers correspond. Each byte is corresponding to a
 * character. Does not support multi-byte characters.
 *
 * @param bytes Array of numbers representing
 *     characters.
 * @return Stringification of the array.
 */
export declare function toByteString(bytes: Uint8Array): string;
/**
 * Returns the element-wise XOR of two byte arrays of the same length
 */
export declare function xor(x: Uint8Array, y: Uint8Array): Uint8Array;