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// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.// This module is browser compatible.
import * as hex from "../../encoding/hex.ts";
type SpongePermutator = (data: Uint8Array) => void;
/** Sponge construction option */export interface SpongeOption {  bitsize: number;  rate: number;  dsbyte: number;  permutator: SpongePermutator;}
export type Message = string | ArrayBuffer;
const STATE_SIZE = 200;const TYPE_ERROR_MSG = "sha3: `data` is invalid type";
/** Sponge construction */export class Sponge {  #option: SpongeOption;  #state: Uint8Array;  #rp: number;  #absorbing: boolean;
  constructor(option: SpongeOption) {    this.#option = option;    this.#state = new Uint8Array(STATE_SIZE);    this.#rp = 0;    this.#absorbing = true;  }
  /** Applies padding to internal state */  #pad(): void {    this.#state[this.#rp] ^= this.#option.dsbyte;    this.#state[this.#option.rate - 1] ^= 0x80;  }
  /** Squeezes internal state */  protected squeeze(length: number): Uint8Array {    if (length < 0) {      throw new Error("sha3: length cannot be negative");    }
    this.#pad();
    const hash = new Uint8Array(length);    let pos = 0;    while (length > 0) {      const r = length > this.#option.rate ? this.#option.rate : length;      this.#option.permutator(this.#state);      hash.set(this.#state.slice(0, r), pos);      length -= r;      pos += r;    }
    this.#absorbing = false;    return hash;  }
  /** Updates internal state by absorbing */  update(data: Message): this {    if (!this.#absorbing) {      throw new Error("sha3: cannot update already finalized hash");    }
    let msg: Uint8Array;
    if (typeof data === "string") {      msg = new TextEncoder().encode(data as string);    } else if (typeof data === "object") {      if (data instanceof ArrayBuffer || ArrayBuffer.isView(data)) {        msg = new Uint8Array(data);      } else {        throw new Error(TYPE_ERROR_MSG);      }    } else {      throw new Error(TYPE_ERROR_MSG);    }
    let rp = this.#rp;
    for (let i = 0; i < msg.length; ++i) {      this.#state[rp++] ^= msg[i];      if (rp >= this.#option.rate) {        this.#option.permutator(this.#state);        rp = 0;      }    }
    this.#rp = rp;    return this;  }
  /** Returns the hash in ArrayBuffer */  digest(): ArrayBuffer {    return this.squeeze(this.#option.bitsize >> 3);  }
  /** Returns the hash in given format */  toString(format: "hex" = "hex"): string {    const rawOutput = this.squeeze(this.#option.bitsize >> 3);    switch (format) {      case "hex":        return new TextDecoder().decode(hex.encode(rawOutput));      default:        throw new Error("sha3: invalid output format");    }  }}