cryptobox-hd/src/main/ts/CryptoboxSession.ts

High-level API with persistent storage for Proteus-HD.

import * as Proteus from "proteus-hd";
import {DecryptionError} from "./DecryptionError";
import {ReadOnlyStore} from "./store/ReadOnlyStore";

export class CryptoboxSession {
  public id: string;
  public pk_store: ReadOnlyStore;
  public session: Proteus.session.Session;

  constructor(id: string, pk_store: ReadOnlyStore, session: Proteus.session.Session) {
    this.id = id;
    this.pk_store = pk_store;
    this.session = session;
    Object.freeze(this);
  }

  public decrypt(ciphertext: ArrayBuffer): Promise<Uint8Array> {
    if (ciphertext.byteLength === 0) {
      return Promise.reject(new DecryptionError('Cannot decrypt an empty ArrayBuffer.'));
    }

    const envelope: Proteus.message.Envelope = Proteus.message.Envelope.deserialise(ciphertext);
    return this.session.decrypt(this.pk_store, envelope);
  }

  public encrypt(plaintext: string | Uint8Array, confuse_pre_key_id?: number): Promise<ArrayBuffer> {
    return this.session.encrypt(plaintext, confuse_pre_key_id)
      .then(function (ciphertext: Proteus.message.Envelope) {
         return ciphertext.serialise();
      });
  }

  public fingerprint_local(): string {
    return this.session.local_identity.public_key.fingerprint();
  }

  public fingerprint_remote(): string {
    return this.session.remote_identity.fingerprint();
  }
}