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import type { EncryptedJsonEncoding } from './types.ts';
import { stringToU8a, u8aFixLength } from 'https://deno.land/x/polkadot@0.2.40/util/mod.ts';
import { naclDecrypt } from '../nacl/index.ts';import { scryptEncode, scryptFromU8a } from '../scrypt/index.ts';import { ENCODING, NONCE_LENGTH, SCRYPT_LENGTH } from './constants.ts';
export function jsonDecryptData (encrypted?: Uint8Array | null, passphrase?: string | null, encType: EncryptedJsonEncoding[] = ENCODING): Uint8Array {  if (!encrypted) {    throw new Error('No encrypted data available to decode');  } else if (encType.includes('xsalsa20-poly1305') && !passphrase) {    throw new Error('Password required to decode encrypted data');  }
  let encoded: Uint8Array | null = encrypted;
  if (passphrase) {    let password: Uint8Array;
    if (encType.includes('scrypt')) {      const { params, salt } = scryptFromU8a(encrypted);
      password = scryptEncode(passphrase, salt, params).password;      encrypted = encrypted.subarray(SCRYPT_LENGTH);    } else {      password = stringToU8a(passphrase);    }
    encoded = naclDecrypt(      encrypted.subarray(NONCE_LENGTH),      encrypted.subarray(0, NONCE_LENGTH),      u8aFixLength(password, 256, true)    );  }
  if (!encoded) {    throw new Error('Unable to decode using the supplied passphrase');  }
  return encoded;}