import { IsomorphicBuffer } from "./helpers.js";
/**
 * Calculates the decoded byte length of a Base64 string.
 * @param sBase64 The Base64 encoded string.
 * @param nBlocksSize Optional size to round up to (for buffer alignment).
 * @returns The decoded byte length.
 */
export declare function base64ByteLength(sBase64: string, nBlocksSize?: number): number;
/**
 * Decodes a Base64 string into a Uint8Array.
 * @param sBase64 The Base64 encoded string.
 * @returns The decoded byte array.
 */
export declare function base64DecToArr(sBase64: string): Uint8Array<ArrayBuffer> | Buffer<ArrayBuffer>;
/**
 * Encodes an Uint8Array to Base64URL format.
 * @param aBytes The byte array to encode.
 * @returns The Base64URL encoded string.
 */
export declare function base64UrlEncArr(aBytes: Uint8Array): string;
/**
 * Encodes an ArrayBuffer to Base64URL format.
 * @param aBytes The ArrayBuffer to encode.
 * @returns The Base64URL encoded string.
 */
export declare function base64UrlEncArrBuff(aBytes: ArrayBuffer): string;
/**
 * Encodes an ArrayBuffer/Uint8Array to Base64URL format.
 * @param aBytes The byte array to encode.
 * @returns The Base64URL encoded string.
 */
export declare function base64UrlEncIsomorphicBuffer(aBytes: IsomorphicBuffer): string;
/**
 * Decodes a Base64URL string into an ArrayBuffer/Uint8Array.
 * @param s The Base64URL encoded string.
 * @returns The decoded byte array.
 */
export declare function base64UrlDecToArr(s: string): Uint8Array<ArrayBuffer> | Buffer<ArrayBuffer>;
/**
 * Extracts the binary content from a PEM-formatted private key.
 * @param pem The PEM string containing the private key.
 * @returns The decoded binary content of the private key.
 */
export declare function extractPrivateKey(pem: string): Uint8Array<ArrayBuffer> | Buffer<ArrayBuffer>;
/**
 * Extracts the binary content from a PEM-formatted public key.
 * @param pem The PEM string containing the public key.
 * @returns The decoded binary content of the public key.
 */
export declare function extractPublicKey(pem: string): Uint8Array<ArrayBuffer> | Buffer<ArrayBuffer>;
/**
 * Encodes an ArrayBuffer/Uint8Array to Base64 string.
 * @param aBytes The byte array to encode.
 * @param nBlocksSize Optional size for line breaks in the output.
 * @returns The Base64 encoded string.
 */
export declare function base64EncArr(aBytes: Uint8Array, nBlocksSize?: number): string;
/**
 * Encodes an ArrayBuffer/Uint8Array to Base64 string.
 * @param aBytes The byte array to encode.
 * @param nBlocksSize Optional size for line breaks in the output.
 * @returns The Base64 encoded string.
 */
export declare function base64EncArrBuff(aBytes: ArrayBuffer, nBlocksSize?: number): string;
/**
 * Encodes an ArrayBuffer/Uint8Array to Base64 string.
 * @param aBytes The byte array to encode.
 * @param nBlocksSize Optional size for line breaks in the output.
 * @returns The Base64 encoded string.
 */
export declare function base64EncIsomorphicBuffer(aBytes: IsomorphicBuffer, nBlocksSize?: number): string;
/**
 * Converts a UTF-8 encoded byte array to a JavaScript string.
 * @param aBytes The UTF-8 encoded byte array.
 * @returns The decoded string.
 */
export declare function UTF8ArrToStr(aBytes: Uint8Array): string;
/**
 * IsomorphicBuffer UTF-8 -> string (same name/signature).
 */
/**
 * Converts a UTF-8 encoded byte array to a JavaScript string.
 * @param aBytes The UTF-8 encoded byte array.
 * @returns The decoded string.
 */
export declare function UTF8IsomorphicBufferToStr(aBytes: IsomorphicBuffer): string;
/**
 * Compute UTF-8 byte length for a JS string (same name/signature).
 * Uses correct UTF-8 ranges (1–4 bytes).
 */
export declare function strUTF8ByteLength(sDOMStr: string): number;
/**
 * Converts a JavaScript string to a UTF-8 encoded ArrayBuffer.
 * @param sDOMStr The input string to encode.
 * @returns The UTF-8 encoded ArrayBuffer.
 */
export declare function strToUTF8Arr(sDOMStr: string): Uint8Array<ArrayBuffer>;