import { Buffer } from "../../../buffer.ts";import AuthCipher from "./auth_cipher.js";import StreamCipher from "./stream_cipher.js";import Transform from "../cipher_base.js";import * as aes from "./aes.js";import ebtk from "../evp_bytes_to_key.ts";import { MODES } from "./modes/mod.js";
function Decipher(mode, key, iv) { Transform.call(this);
this._cache = new Splitter(); this._last = void 0; this._cipher = new aes.AES(key); this._prev = Buffer.from(iv); this._mode = mode; this._autopadding = true;}
Decipher.prototype = Object.create(Transform.prototype, { constructor: { value: Decipher, enumerable: false, writable: true, configurable: true, },});
Decipher.prototype._update = function (data) { this._cache.add(data); var chunk; var thing; var out = []; while ((chunk = this._cache.get(this._autopadding))) { thing = this._mode.decrypt(this, chunk); out.push(thing); } return Buffer.concat(out);};
Decipher.prototype._final = function () { var chunk = this._cache.flush(); if (this._autopadding) { return unpad(this._mode.decrypt(this, chunk)); } else if (chunk) { throw new Error("data not multiple of block length"); }};
Decipher.prototype.setAutoPadding = function (setTo) { this._autopadding = !!setTo; return this;};
function Splitter() { this.cache = Buffer.allocUnsafe(0);}
Splitter.prototype.add = function (data) { this.cache = Buffer.concat([this.cache, data]);};
Splitter.prototype.get = function (autoPadding) { var out; if (autoPadding) { if (this.cache.length > 16) { out = this.cache.slice(0, 16); this.cache = this.cache.slice(16); return out; } } else { if (this.cache.length >= 16) { out = this.cache.slice(0, 16); this.cache = this.cache.slice(16); return out; } }
return null;};
Splitter.prototype.flush = function () { if (this.cache.length) return this.cache;};
function unpad(last) { var padded = last[15]; if (padded < 1 || padded > 16) { throw new Error("unable to decrypt data"); } var i = -1; while (++i < padded) { if (last[i + (16 - padded)] !== padded) { throw new Error("unable to decrypt data"); } } if (padded === 16) return;
return last.slice(0, 16 - padded);}
export function createDecipheriv(suite, password, iv) { var config = MODES[suite.toLowerCase()]; if (!config) throw new TypeError("invalid suite type");
if (typeof iv === "string") iv = Buffer.from(iv); if (config.mode !== "GCM" && iv.length !== config.iv) { throw new TypeError("invalid iv length " + iv.length); }
if (typeof password === "string") password = Buffer.from(password); if (password.length !== config.key / 8) { throw new TypeError("invalid key length " + password.length); }
if (config.type === "stream") { return new StreamCipher(config.module, password, iv, true); } else if (config.type === "auth") { return new AuthCipher(config.module, password, iv, true); }
return new Decipher(config.module, password, iv);}
export function createDecipher(suite, password) { var config = MODES[suite.toLowerCase()]; if (!config) throw new TypeError("invalid suite type");
var keys = ebtk(password, false, config.key, config.iv); return createDecipheriv(suite, keys.key, keys.iv);}