implement JS-only Taler, remove emscripten

1 files changed, 0 insertions, 1657 deletions

diff --git a/src/crypto/emscInterface.ts b/src/crypto/emscInterface.ts
deleted file mode 100644
index da5442a61..000000000
--- a/src/crypto/emscInterface.ts
+++ /dev/null
@@ -1,1657 +0,0 @@
-/*
- This file is part of TALER
- (C) 2015 GNUnet e.V.
-
- TALER is free software; you can redistribute it and/or modify it under the
- terms of the GNU General Public License as published by the Free Software
- Foundation; either version 3, or (at your option) any later version.
-
- TALER is distributed in the hope that it will be useful, but WITHOUT ANY
- WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
- A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
-
- You should have received a copy of the GNU General Public License along with
- TALER; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
- */
-
-
-/**
- * Medium-level interface to emscripten-compiled modules used
- * by the wallet.  Handles memory management by allocating by allocating
- * objects in arenas that then can be disposed of all at once.
- *
- * The high-level interface (using WebWorkers) is exposed in src/cryptoApi.ts.
- */
-
-/**
- * Imports.
- */
-import { AmountJson } from "../amounts";
-
-/**
- * Size of a native pointer.  Must match the size
- * use when compiling via emscripten.
- */
-const PTR_SIZE = 4;
-
-const GNUNET_OK = 1;
-
-
-/**
- * Signature of the function that retrieves emscripten
- * function implementations.
- */
-export interface EmscFunGen {
-  (name: string,
-   ret: string,
-   args: string[]): ((...x: Array<number|string>) => any);
-  (name: string,
-   ret: "number",
-   args: string[]): ((...x: Array<number|string>) => number);
-  (name: string,
-   ret: "void",
-   args: string[]): ((...x: Array<number|string>) => void);
-  (name: string,
-   ret: "string",
-   args: string[]): ((...x: Array<number|string>) => string);
-}
-
-
-interface EmscLib {
-  cwrap: EmscFunGen;
-
-  ccall(name: string, ret: "number"|"string", argTypes: any[], args: any[]): any;
-
-  stringToUTF8(s: string, addr: number, maxLength: number): void;
-
-  onRuntimeInitialized(f: () => void): void;
-
-  readBinary?: (filename: string) => Promise<ArrayBuffer>;
-
-  calledRun?: boolean;
-
-  _free(ptr: number): void;
-
-  _malloc(n: number): number;
-
-  UTF8ToString(p: number, len?: number): string;
-
-  getValue(ptr: number, type: string, noSafe?: boolean): number;
-
-  setValue(ptr: number, value: number, type: string, noSafe?: boolean): void;
-
-  writeStringToMemory(s: string, buffer: number, dontAddNull?: boolean): void;
-}
-
-interface EmscFunctions {
-  amount_add(a1: number, a2: number, a3: number): number;
-  amount_cmp(a1: number, a2: number): number;
-  amount_get_zero(a1: string, a2: number): number;
-  amount_hton(a1: number, a2: number): void;
-  amount_normalize(a1: number): void;
-  amount_ntoh(a1: number, a2: number): void;
-  amount_subtract(a1: number, a2: number, a3: number): number;
-  ecdh_eddsa(a1: number, a2: number, a3: number): number;
-  eddsa_sign(a1: number, a2: number, a3: number): number;
-  eddsa_verify(a1: number, a2: number, a3: number, a4: number): number;
-  free(ptr: number): void;
-  get_currency(a: number): string;
-  get_fraction(a: number): number;
-  get_value(a: number): number;
-  hash(a1: number, a2: number, a3: number): void;
-  hash_context_abort(ctx: number): void;
-  hash_context_finish(a1: number, a2: number): void;
-  hash_context_read(a1: number, a2: number, a3: number): void;
-  hash_create_random(a1: number, a2: number): void;
-  memmove(a1: number, a2: number, a3: number): number;
-  random_block(a1: number, a2: number, a3: number): void;
-  rsa_blinding_key_free(a1: number): void;
-  rsa_public_key_free(a1: number): void;
-  rsa_private_key_free(a1: number): void;
-  rsa_signature_free(a1: number): void;
-  rsa_verify(msgHash: number, sig: number, pubKey: number): number;
-  setup_fresh_coin(a1: number, a2: number, a3: number): void;
-  string_to_data(a1: number, a2: number, a3: number, a4: number): number;
-}
-
-interface EmscAllocFunctions {
-  data_to_string_alloc(a1: number, a2: number): number;
-  ecdhe_key_create(): number;
-  ecdhe_public_key_from_private(a1: number): number;
-  ecdsa_key_create(): number;
-  ecdsa_public_key_from_private(a1: number): number;
-  eddsa_key_create(): number;
-  eddsa_public_key_from_private(a1: number): number;
-  /**
-   * Note that value_1 and value_2 are the first 64-bit parameter,
-   * and not two separate parameters (by the emscripten calling convention).
-   */
-  get_amount(value_1: number, value_2: number, fraction: number, currency: string): number;
-  hash_context_start(): number;
-  malloc(size: number): number;
-  purpose_create(a1: number, a2: number, a3: number): number;
-  rsa_blind(a1: number, a2: number, a3: number, a4: number, a5: number): number;
-  rsa_blinding_key_create(a1: number): number;
-  rsa_blinding_key_decode(a1: number, a2: number): number;
-  rsa_blinding_key_encode(a1: number, a2: number): number;
-  rsa_private_key_create(len: number): number;
-  rsa_private_key_decode(a1: number, a2: number): number;
-  rsa_private_key_encode(a1: number, a2: number): number;
-  rsa_private_key_get_public(privKeyPtr: number): number;
-  rsa_public_key_decode(a1: number, a2: number): number;
-  rsa_public_key_encode(a1: number, a2: number): number;
-  rsa_signature_decode(a1: number, a2: number): number;
-  rsa_signature_encode(a1: number, a2: number): number;
-  rsa_sign_blinded(keyPtr: number, msgPtr: number, msgLen: number): number;
-  rsa_unblind(a1: number, a2: number, a3: number): number;
-}
-
-export class EmscEnvironment {
-
-  /**
-   * Emscripten functions that don't do any memory allocations.
-   */
-  public funcs: EmscFunctions;
-
-  /**
-   * Emscripten functions that allocate memory.
-   */
-  public allocFuncs: EmscAllocFunctions;
-
-  public lib: EmscLib;
-
-  constructor(lib: EmscLib) {
-    const getEmsc: EmscFunGen = (name: string, ret: any, argTypes: any[]) => {
-      return (...args: any[]) => {
-        return lib.ccall(name, ret, argTypes, args);
-      };
-    };
-    this.lib = lib;
-    this.allocFuncs = {
-      data_to_string_alloc: getEmsc("GNUNET_STRINGS_data_to_string_alloc", "number", ["number", "number"]),
-      ecdhe_key_create: getEmsc("GNUNET_CRYPTO_ecdhe_key_create", "number", []),
-      ecdhe_public_key_from_private: getEmsc( "TALER_WRALL_ecdhe_public_key_from_private", "number", ["number"]),
-      ecdsa_key_create: getEmsc("GNUNET_CRYPTO_ecdsa_key_create", "number", []),
-      ecdsa_public_key_from_private: getEmsc( "TALER_WRALL_ecdsa_public_key_from_private", "number", ["number"]),
-      eddsa_key_create: getEmsc("GNUNET_CRYPTO_eddsa_key_create", "number", []),
-      eddsa_public_key_from_private: getEmsc( "TALER_WRALL_eddsa_public_key_from_private", "number", ["number"]),
-      get_amount: getEmsc("TALER_WRALL_get_amount", "number", ["number", "number", "number", "string"]),
-      hash_context_start: getEmsc("GNUNET_CRYPTO_hash_context_start", "number", []),
-      malloc: (size: number) => lib._malloc(size),
-      purpose_create: getEmsc("TALER_WRALL_purpose_create", "number", ["number", "number", "number"]),
-      rsa_blind: getEmsc("GNUNET_CRYPTO_rsa_blind", "number", ["number", "number", "number", "number", "number"]),
-      rsa_blinding_key_create: getEmsc("GNUNET_CRYPTO_rsa_blinding_key_create", "number", ["number"]),
-      rsa_blinding_key_decode: getEmsc("GNUNET_CRYPTO_rsa_blinding_key_decode", "number", ["number", "number"]),
-      rsa_blinding_key_encode: getEmsc("GNUNET_CRYPTO_rsa_blinding_key_encode", "number", ["number", "number"]),
-      rsa_private_key_create: getEmsc("GNUNET_CRYPTO_rsa_private_key_create", "number", ["number"]),
-      rsa_private_key_decode: getEmsc("GNUNET_CRYPTO_rsa_private_key_decode", "number", ["number", "number"]),
-      rsa_private_key_encode: getEmsc("GNUNET_CRYPTO_rsa_private_key_encode", "number", ["number", "number"]),
-      rsa_private_key_get_public: getEmsc("GNUNET_CRYPTO_rsa_private_key_get_public", "number", ["number"]),
-      rsa_public_key_decode: getEmsc("GNUNET_CRYPTO_rsa_public_key_decode", "number", ["number", "number"]),
-      rsa_public_key_encode: getEmsc("GNUNET_CRYPTO_rsa_public_key_encode", "number", ["number", "number"]),
-      rsa_signature_decode: getEmsc("GNUNET_CRYPTO_rsa_signature_decode", "number", ["number", "number"]),
-      rsa_signature_encode: getEmsc("GNUNET_CRYPTO_rsa_signature_encode", "number", ["number", "number"]),
-      rsa_sign_blinded: getEmsc("GNUNET_CRYPTO_rsa_sign_blinded", "number", ["number", "number", "number"]),
-      rsa_unblind: getEmsc("GNUNET_CRYPTO_rsa_unblind", "number", ["number", "number", "number"]),
-    };
-    this.funcs = {
-      amount_add: getEmsc("TALER_amount_add", "number", ["number", "number", "number"]),
-      amount_cmp: getEmsc("TALER_amount_cmp", "number", ["number", "number"]),
-      amount_get_zero: getEmsc("TALER_amount_get_zero", "number", ["string", "number"]),
-      amount_hton: getEmsc("TALER_amount_hton", "void", ["number", "number"]),
-      amount_normalize: getEmsc("TALER_amount_normalize", "void", ["number"]),
-      amount_ntoh: getEmsc("TALER_amount_ntoh", "void", ["number", "number"]),
-      amount_subtract: getEmsc("TALER_amount_subtract", "number", ["number", "number", "number"]),
-      ecdh_eddsa: getEmsc("GNUNET_CRYPTO_ecdh_eddsa", "number", ["number", "number", "number"]),
-      eddsa_sign: getEmsc("GNUNET_CRYPTO_eddsa_sign", "number", ["number", "number", "number"]),
-      eddsa_verify: getEmsc("GNUNET_CRYPTO_eddsa_verify", "number", ["number", "number", "number", "number"]),
-      free: (ptr: number) => lib._free(ptr),
-      get_currency: getEmsc("TALER_WR_get_currency", "string", ["number"]),
-      get_fraction: getEmsc("TALER_WR_get_fraction", "number", ["number"]),
-      get_value: getEmsc("TALER_WR_get_value", "number", ["number"]),
-      hash: getEmsc("GNUNET_CRYPTO_hash", "void", ["number", "number", "number"]),
-      hash_context_abort: getEmsc("GNUNET_CRYPTO_hash_context_abort", "void", ["number"]),
-      hash_context_finish: getEmsc("GNUNET_CRYPTO_hash_context_finish", "void", ["number", "number"]),
-      hash_context_read: getEmsc("GNUNET_CRYPTO_hash_context_read", "void", ["number", "number", "number"]),
-      hash_create_random: getEmsc("GNUNET_CRYPTO_hash_create_random", "void", ["number", "number"]),
-      memmove: getEmsc("memmove", "number", ["number", "number", "number"]),
-      random_block: getEmsc("GNUNET_CRYPTO_random_block", "void", ["number", "number", "number"]),
-      rsa_blinding_key_free: getEmsc("GNUNET_CRYPTO_rsa_blinding_key_free", "void", ["number"]),
-      rsa_public_key_free: getEmsc("GNUNET_CRYPTO_rsa_public_key_free", "void", ["number"]),
-      rsa_private_key_free: getEmsc("GNUNET_CRYPTO_rsa_private_key_free", "void", ["number"]),
-      rsa_signature_free: getEmsc("GNUNET_CRYPTO_rsa_signature_free", "void", ["number"]),
-      rsa_verify: getEmsc("GNUNET_CRYPTO_rsa_verify", "number", ["number", "number", "number"]),
-      setup_fresh_coin: getEmsc("TALER_setup_fresh_coin", "void", ["number", "number", "number"]),
-      string_to_data: getEmsc("GNUNET_STRINGS_string_to_data", "number", ["number", "number", "number", "number"]),
-    };
-  }
-}
-
-
-/**
- * Constants for signatures purposes, define what the signatures vouches for.
- */
-export enum SignaturePurpose {
-  RESERVE_WITHDRAW = 1200,
-  WALLET_COIN_DEPOSIT = 1201,
-  MASTER_DENOMINATION_KEY_VALIDITY = 1025,
-  WALLET_COIN_MELT = 1202,
-  TEST = 4242,
-  MERCHANT_PAYMENT_OK = 1104,
-  MASTER_WIRE_FEES = 1028,
-  WALLET_COIN_PAYBACK = 1203,
-  WALLET_COIN_LINK = 1204,
-}
-
-
-/**
- * Desired quality levels for random numbers.
- */
-export enum RandomQuality {
-  WEAK = 0,
-  STRONG = 1,
-  NONCE = 2,
-}
-
-
-/**
- * Object that is allocated in some arena.
- */
-interface ArenaObject {
-  destroy(): void;
-}
-
-
-/**
- * Context for cummulative hashing.
- */
-export class HashContext implements ArenaObject {
-  private hashContextPtr: number | undefined;
-
-  constructor(private emsc: EmscEnvironment) {
-    this.hashContextPtr = emsc.allocFuncs.hash_context_start();
-  }
-
-  /**
-   * Add data to be hashed.
-   */
-  read(obj: PackedArenaObject): void {
-    if (!this.hashContextPtr) {
-      throw Error("assertion failed");
-    }
-    this.emsc.funcs.hash_context_read(this.hashContextPtr, obj.nativePtr, obj.size());
-  }
-
-  /**
-   * Finish the hash computation.
-   */
-  finish(h: HashCode) {
-    if (!this.hashContextPtr) {
-      throw Error("assertion failed");
-    }
-    h.alloc();
-    this.emsc.funcs.hash_context_finish(this.hashContextPtr, h.nativePtr);
-  }
-
-  /**
-   * Abort hashing without computing the result.
-   */
-  destroy(): void {
-    if (this.hashContextPtr) {
-      this.emsc.funcs.hash_context_abort(this.hashContextPtr);
-    }
-    this.hashContextPtr = undefined;
-  }
-}
-
-
-/**
- * Arena object that points to an allocated block of memory.
- */
-abstract class MallocArenaObject implements ArenaObject {
-  protected _nativePtr: number | undefined = undefined;
-
-  /**
-   * Is this a weak reference to the underlying memory?
-   */
-  isWeak = false;
-
-  destroy(): void {
-    if (this._nativePtr && !this.isWeak) {
-      this.emsc.funcs.free(this.nativePtr);
-      this._nativePtr = undefined;
-    }
-  }
-
-  constructor(public emsc: EmscEnvironment, arena?: Arena) {
-    if (!arena) {
-      if (arenaStack.length === 0) {
-        throw Error("No arena available");
-      }
-      arena = arenaStack[arenaStack.length - 1];
-    }
-    arena.put(this);
-  }
-
-  alloc(size: number) {
-    if (this._nativePtr !== undefined) {
-      throw Error("Double allocation");
-    }
-    this.nativePtr = this.emsc.allocFuncs.malloc(size);
-  }
-
-  set nativePtr(v: number) {
-    if (v === undefined) {
-      throw Error("Native pointer must be a number or null");
-    }
-    this._nativePtr = v;
-  }
-
-  get nativePtr() {
-    // We want to allow latent allocation
-    // of native wrappers, but we never want to
-    // pass 'undefined' to emscripten.
-    if (this._nativePtr === undefined) {
-      throw Error("Native pointer not initialized");
-    }
-    return this._nativePtr;
-  }
-}
-
-
-/**
- * An arena stores objects that will be deallocated
- * at the same time.
- */
-interface Arena {
-  put(obj: ArenaObject): void;
-  destroy(): void;
-}
-
-
-/**
- * Arena that must be manually destroyed.
- */
-class SimpleArena implements Arena {
-  protected heap: ArenaObject[];
-
-  constructor() {
-    this.heap = [];
-  }
-
-  put(obj: ArenaObject) {
-    this.heap.push(obj);
-  }
-
-  destroy() {
-    for (const obj of this.heap) {
-      obj.destroy();
-    }
-    this.heap = [];
-  }
-}
-
-
-/**
- * Arena that destroys all its objects once control has returned to the message
- * loop.
- */
-class SyncArena extends SimpleArena {
-  private isScheduled: boolean;
-
-  constructor() {
-    super();
-  }
-
-  pub(obj: MallocArenaObject) {
-    super.put(obj);
-    if (!this.isScheduled) {
-      this.schedule();
-    }
-    this.heap.push(obj);
-  }
-
-  private schedule() {
-    this.isScheduled = true;
-    Promise.resolve().then(() => {
-      this.isScheduled = false;
-      this.destroy();
-    });
-  }
-}
-
-export const arenaStack: Arena[] = [];
-arenaStack.push(new SyncArena());
-
-
-/**
- * Representation of monetary value in a given currency.
- */
-export class Amount extends MallocArenaObject {
-  constructor(emsc: EmscEnvironment, args?: AmountJson, arena?: Arena) {
-    super(emsc, arena);
-    if (args) {
-      this.nativePtr = emsc.allocFuncs.get_amount(args.value,
-                                            0,
-                                            args.fraction,
-                                            args.currency);
-    } else {
-      this.nativePtr = emsc.allocFuncs.get_amount(0, 0, 0, "");
-    }
-  }
-
-  static getZero(emsc: EmscEnvironment, currency: string, a?: Arena): Amount {
-    const am = new Amount(emsc, undefined, a);
-    const r = emsc.funcs.amount_get_zero(currency, am.nativePtr);
-    if (r !== GNUNET_OK) {
-      throw Error("invalid currency");
-    }
-    return am;
-  }
-
-
-  toNbo(a?: Arena): AmountNbo {
-    const x = new AmountNbo(this.emsc, a);
-    x.alloc();
-    this.emsc.funcs.amount_hton(x.nativePtr, this.nativePtr);
-    return x;
-  }
-
-  fromNbo(nbo: AmountNbo): void {
-    this.emsc.funcs.amount_ntoh(this.nativePtr, nbo.nativePtr);
-  }
-
-  get value() {
-    return this.emsc.funcs.get_value(this.nativePtr);
-  }
-
-  get fraction() {
-    return this.emsc.funcs.get_fraction(this.nativePtr);
-  }
-
-  get currency(): string {
-    return this.emsc.funcs.get_currency(this.nativePtr);
-  }
-
-  toJson(): AmountJson {
-    return {
-      currency: this.emsc.funcs.get_currency(this.nativePtr),
-      fraction: this.emsc.funcs.get_fraction(this.nativePtr),
-      value: this.emsc.funcs.get_value(this.nativePtr),
-    };
-  }
-
-  /**
-   * Add an amount to this amount.
-   */
-  add(a: Amount) {
-    const res = this.emsc.funcs.amount_add(this.nativePtr, a.nativePtr, this.nativePtr);
-    if (res < 1) {
-      // Overflow
-      return false;
-    }
-    return true;
-  }
-
-  /**
-   * Perform saturating subtraction on amounts.
-   */
-  sub(a: Amount) {
-    // this = this - a
-    const res = this.emsc.funcs.amount_subtract(this.nativePtr, this.nativePtr, a.nativePtr);
-    if (res === 0) {
-      // Underflow
-      return false;
-    }
-    if (res > 0) {
-      return true;
-    }
-    throw Error("Incompatible currencies");
-  }
-
-  cmp(a: Amount) {
-    // If we don't check this, the c code aborts.
-    if (this.currency !== a.currency) {
-      throw Error(`incomparable currencies (${this.currency} and ${a.currency})`);
-    }
-    return this.emsc.funcs.amount_cmp(this.nativePtr, a.nativePtr);
-  }
-
-  normalize() {
-    this.emsc.funcs.amount_normalize(this.nativePtr);
-  }
-}
-
-
-/**
- * Count the UTF-8 characters in a JavaScript string.
- */
-function countUtf8Bytes(str: string): number {
-  let s = str.length;
-  // JavaScript strings are UTF-16 arrays
-  for (let i = str.length - 1; i >= 0; i--) {
-    const code = str.charCodeAt(i);
-    if (code > 0x7f && code <= 0x7ff) {
-      // We need an extra byte in utf-8 here
-      s++;
-    } else if (code > 0x7ff && code <= 0xffff) {
-      // We need two extra bytes in utf-8 here
-      s += 2;
-    }
-    // Skip over the other surrogate
-    if (code >= 0xDC00 && code <= 0xDFFF) {
-      i--;
-    }
-  }
-  return s;
-}
-
-
-/**
- * Managed reference to a contiguous block of memory in the Emscripten heap.
- * Can be converted from / to a serialized representation.
- * Should contain only data, not pointers.
- */
-abstract class PackedArenaObject extends MallocArenaObject {
-  abstract size(): number;
-
-  constructor(emsc: EmscEnvironment, a?: Arena) {
-    super(emsc, a);
-  }
-
-  randomize(qual: RandomQuality = RandomQuality.STRONG): void {
-    this.emsc.funcs.random_block(qual, this.nativePtr, this.size());
-  }
-
-  toCrock(): string {
-    const d = this.emsc.allocFuncs.data_to_string_alloc(this.nativePtr, this.size());
-    const s = this.emsc.lib.UTF8ToString(d);
-    this.emsc.funcs.free(d);
-    return s;
-  }
-
-  toJson(): any {
-    // Per default, the json encoding of
-    // packed arena objects is just the crockford encoding.
-    // Subclasses typically want to override this.
-    return this.toCrock();
-  }
-
-  loadCrock(s: string) {
-    this.alloc();
-    // We need to get the javascript string
-    // to the emscripten heap first.
-    const buf = ByteArray.fromStringWithNull(this.emsc, s);
-    const res = this.emsc.funcs.string_to_data(buf.nativePtr,
-                                  s.length,
-                                  this.nativePtr,
-                                  this.size());
-    buf.destroy();
-    if (res < 1) {
-      throw {error: "wrong encoding"};
-    }
-  }
-
-  alloc() {
-    // FIXME: should the client be allowed to call alloc multiple times?
-    if (!this._nativePtr) {
-      this.nativePtr = this.emsc.allocFuncs.malloc(this.size());
-    }
-  }
-
-  hash(): HashCode {
-    const x = new HashCode(this.emsc);
-    x.alloc();
-    this.emsc.funcs.hash(this.nativePtr, this.size(), x.nativePtr);
-    return x;
-  }
-
-  hexdump() {
-    const bytes: string[] = [];
-    for (let i = 0; i < this.size(); i++) {
-      let b = this.emsc.lib.getValue(this.nativePtr + i, "i8");
-      b = (b + 256) % 256;
-      bytes.push("0".concat(b.toString(16)).slice(-2));
-    }
-    const lines: string[] = [];
-    for (let i = 0; i < bytes.length; i += 8) {
-      lines.push(bytes.slice(i, i + 8).join(","));
-    }
-    return lines.join("\n");
-  }
-}
-
-
-/**
- * Amount, encoded for network transmission.
- */
-export class AmountNbo extends PackedArenaObject {
-  size() {
-    return 24;
-  }
-
-  toJson(): any {
-    const a = new SimpleArena();
-    const am = new Amount(this.emsc, undefined, a);
-    am.fromNbo(this);
-    const json = am.toJson();
-    a.destroy();
-    return json;
-  }
-}
-
-
-/**
- * Create a packed arena object from the base32 crockford encoding.
- */
-function fromCrock<T extends PackedArenaObject>(emsc: EmscEnvironment, s: string, ctor: Ctor<T>): T {
-  const x: T = new ctor(emsc);
-  x.alloc();
-  x.loadCrock(s);
-  return x;
-}
-
-
-/**
- * Create a packed arena object from the base32 crockford encoding for objects
- * that have a special decoding function.
- */
-function fromCrockDecoded<T extends MallocArenaObject>(emsc: EmscEnvironment, s: string,
-                                                       ctor: Ctor<T>,
-                                                       decodeFn: (p: number, s: number) => number): T {
-  const obj = new ctor(emsc);
-  const buf = ByteArray.fromCrock(emsc, s);
-  obj.nativePtr = decodeFn(buf.nativePtr, buf.size());
-  buf.destroy();
-  return obj;
-}
-
-
-/**
- * Encode an object using a special encoding function.
- */
-function encode<T extends MallocArenaObject>(obj: T, encodeFn: any, arena?: Arena): ByteArray {
-  const ptr = obj.emsc.allocFuncs.malloc(PTR_SIZE);
-  const len = encodeFn(obj.nativePtr, ptr);
-  const res = new ByteArray(obj.emsc, len, undefined, arena);
-  res.nativePtr = obj.emsc.lib.getValue(ptr, "*");
-  obj.emsc.funcs.free(ptr);
-  return res;
-}
-
-
-/**
- * Private EdDSA key.
- */
-export class EddsaPrivateKey extends PackedArenaObject {
-  static create(emsc: EmscEnvironment, a?: Arena): EddsaPrivateKey {
-    const obj = new EddsaPrivateKey(emsc, a);
-    obj.nativePtr = emsc.allocFuncs.eddsa_key_create();
-    return obj;
-  }
-
-  size() {
-    return 32;
-  }
-
-  getPublicKey(a?: Arena): EddsaPublicKey {
-    const obj = new EddsaPublicKey(this.emsc, a);
-    obj.nativePtr = this.emsc.allocFuncs.eddsa_public_key_from_private(this.nativePtr);
-    return obj;
-  }
-
-  static fromCrock(emsc: EmscEnvironment, s: string): EddsaPrivateKey {
-    return fromCrock(emsc, s, this);
-  }
-}
-
-
-/**
- * Low-level handle to an EdDSA private key.
- */
-export class EcdsaPrivateKey extends PackedArenaObject {
-  static create(emsc: EmscEnvironment, a?: Arena): EcdsaPrivateKey {
-    const obj = new EcdsaPrivateKey(emsc, a);
-    obj.nativePtr = emsc.allocFuncs.ecdsa_key_create();
-    return obj;
-  }
-
-  size() {
-    return 32;
-  }
-
-  getPublicKey(a?: Arena): EcdsaPublicKey {
-    const obj = new EcdsaPublicKey(this.emsc, a);
-    obj.nativePtr = this.emsc.allocFuncs.ecdsa_public_key_from_private(this.nativePtr);
-    return obj;
-  }
-
-  static fromCrock(emsc: EmscEnvironment, s: string): EcdsaPrivateKey {
-    return fromCrock(emsc, s, this);
-  }
-}
-
-
-/**
- * Low-level handle to an ECDHE private key.
- */
-export class EcdhePrivateKey extends PackedArenaObject {
-  static create(emsc: EmscEnvironment, a?: Arena): EcdhePrivateKey {
-    const obj = new EcdhePrivateKey(emsc, a);
-    obj.nativePtr = emsc.allocFuncs.ecdhe_key_create();
-    return obj;
-  }
-
-  size() {
-    return 32;
-  }
-
-  getPublicKey(a?: Arena): EcdhePublicKey {
-    const obj = new EcdhePublicKey(this.emsc, a);
-    obj.nativePtr = this.emsc.allocFuncs.ecdhe_public_key_from_private(this.nativePtr);
-    return obj;
-  }
-
-  static fromCrock(emsc: EmscEnvironment, s: string): EcdhePrivateKey {
-    return fromCrock(emsc, s, this);
-  }
-}
-
-
-/**
- * Constructor for a given type.
- */
-interface Ctor<T> {
-  new(emsc: EmscEnvironment): T;
-}
-
-
-/**
- * Low-level handle to an EdDSA public key.
- */
-export class EddsaPublicKey extends PackedArenaObject {
-  size() {
-    return 32;
-  }
-
-  static fromCrock(emsc: EmscEnvironment, s: string): EddsaPublicKey {
-    return fromCrock(emsc, s, this);
-  }
-}
-
-/**
- * Low-level handle to an ECDSA public key.
- */
-export class EcdsaPublicKey extends PackedArenaObject {
-  size() {
-    return 32;
-  }
-
-  static fromCrock(emsc: EmscEnvironment, s: string): EcdsaPublicKey {
-    return fromCrock(emsc, s, this);
-  }
-}
-
-
-/**
- * Low-level handle to an ECDHE public key.
- */
-export class EcdhePublicKey extends PackedArenaObject {
-  size() {
-    return 32;
-  }
-
-  static fromCrock(emsc: EmscEnvironment, s: string): EcdhePublicKey {
-    return fromCrock(emsc, s, this);
-  }
-}
-
-
-/**
- * Low-level handle to a blinding key secret.
- */
-export class RsaBlindingKeySecret extends PackedArenaObject {
-  size() {
-    return 32;
-  }
-
-  /**
-   * Create a random blinding key secret.
-   */
-  static create(emsc: EmscEnvironment, a?: Arena): RsaBlindingKeySecret {
-    const o = new RsaBlindingKeySecret(emsc, a);
-    o.alloc();
-    o.randomize();
-    return o;
-  }
-
-  static fromCrock(emsc: EmscEnvironment, s: string): RsaBlindingKeySecret {
-    return fromCrock(emsc, s, this);
-  }
-}
-
-
-/**
- * Low-level handle to a hash code.
- */
-export class HashCode extends PackedArenaObject {
-  size() {
-    return 64;
-  }
-
-  static fromCrock(emsc: EmscEnvironment, s: string): HashCode {
-    return fromCrock(emsc, s, this);
-  }
-
-  random(qual: RandomQuality = RandomQuality.STRONG) {
-    this.alloc();
-    this.emsc.funcs.hash_create_random(qual, this.nativePtr);
-  }
-}
-
-
-/**
- * Low-level handle to a byte array.
- */
-export class ByteArray extends PackedArenaObject {
-  private allocatedSize: number;
-
-  size() {
-    return this.allocatedSize;
-  }
-
-  constructor(public emsc: EmscEnvironment, desiredSize: number, init?: number, a?: Arena) {
-    super(emsc, a);
-    if (init === undefined) {
-      this.nativePtr = this.emsc.allocFuncs.malloc(desiredSize);
-    } else {
-      this.nativePtr = init;
-    }
-    this.allocatedSize = desiredSize;
-  }
-
-  static fromStringWithoutNull(emsc: EmscEnvironment, s: string, a?: Arena): ByteArray {
-    // UTF-8 bytes, including 0-terminator
-    const terminatedByteLength = countUtf8Bytes(s) + 1;
-    const hstr = emsc.allocFuncs.malloc(terminatedByteLength);
-    emsc.lib.stringToUTF8(s, hstr, terminatedByteLength);
-    return new ByteArray(emsc, terminatedByteLength - 1, hstr, a);
-  }
-
-  static fromStringWithNull(emsc: EmscEnvironment, s: string, a?: Arena): ByteArray {
-    // UTF-8 bytes, including 0-terminator
-    const terminatedByteLength = countUtf8Bytes(s) + 1;
-    const hstr = emsc.allocFuncs.malloc(terminatedByteLength);
-    emsc.lib.stringToUTF8(s, hstr, terminatedByteLength);
-    return new ByteArray(emsc, terminatedByteLength, hstr, a);
-  }
-
-  static fromCrock(emsc: EmscEnvironment, s: string, a?: Arena): ByteArray {
-    // this one is a bit more complicated than the other fromCrock functions,
-    // since we don't have a fixed size
-    const byteLength = countUtf8Bytes(s);
-    const hstr = emsc.allocFuncs.malloc(byteLength + 1);
-    emsc.lib.stringToUTF8(s, hstr, byteLength + 1);
-    const decodedLen = Math.floor((byteLength * 5) / 8);
-    const ba = new ByteArray(emsc, decodedLen, undefined, a);
-    const res = emsc.funcs.string_to_data(hstr, byteLength, ba.nativePtr, decodedLen);
-    emsc.funcs.free(hstr);
-    if (res !== GNUNET_OK) {
-      throw Error("decoding failed");
-    }
-    return ba;
-  }
-}
-
-
-/**
- * Data to sign, together with a header that includes a purpose id
- * and size.
- */
-export class EccSignaturePurpose extends PackedArenaObject {
-  size() {
-    return this.payloadSize + 8;
-  }
-
-  private payloadSize: number;
-
-  constructor(emsc: EmscEnvironment,
-              purpose: SignaturePurpose,
-              payload: PackedArenaObject,
-              a?: Arena) {
-    super(emsc, a);
-    this.nativePtr = emsc.allocFuncs.purpose_create(purpose,
-                                                      payload.nativePtr,
-                                                      payload.size());
-    this.payloadSize = payload.size();
-  }
-}
-
-
-abstract class SignatureStruct {
-  abstract fieldTypes(): any[];
-
-  abstract purpose(): SignaturePurpose;
-
-  private members: any = {};
-
-  constructor(public emsc: EmscEnvironment, x: { [name: string]: any }) {
-    for (const k in x) {
-      this.set(k, x[k]);
-    }
-  }
-
-  toPurpose(a?: Arena): EccSignaturePurpose {
-    let totalSize = 0;
-    for (const f of this.fieldTypes()) {
-      const name = f[0];
-      const member = this.members[name];
-      if (!member) {
-        throw Error(`Member ${name} not set`);
-      }
-      totalSize += member.size();
-    }
-
-    const buf = this.emsc.allocFuncs.malloc(totalSize);
-    let ptr = buf;
-    for (const f of this.fieldTypes()) {
-      const name = f[0];
-      const member = this.members[name];
-      const size = member.size();
-      this.emsc.funcs.memmove(ptr, member.nativePtr, size);
-      ptr += size;
-    }
-    const ba = new ByteArray(this.emsc, totalSize, buf, a);
-    return new EccSignaturePurpose(this.emsc, this.purpose(), ba);
-  }
-
-
-  toJson() {
-    const res: any = {};
-    for (const f of this.fieldTypes()) {
-      const name = f[0];
-      const member = this.members[name];
-      if (!member) {
-        throw Error(`Member ${name} not set`);
-      }
-      res[name] = member.toJson();
-    }
-    res.purpose = this.purpose();
-    return res;
-  }
-
-  protected set(name: string, value: PackedArenaObject) {
-    const typemap: any = {};
-    for (const f of this.fieldTypes()) {
-      typemap[f[0]] = f[1];
-    }
-    if (!(name in typemap)) {
-      throw Error(`Key ${name} not found`);
-    }
-    if (!(value instanceof typemap[name])) {
-      throw Error(`Wrong type for ${name}`);
-    }
-    this.members[name] = value;
-  }
-}
-
-
-/**
- * Arguments to constructor of [[WithdrawRequestPS]].
- */
-export interface WithdrawRequestPS_Args {
-  /**
-   * Reserve public key.
-   */
-  reserve_pub: EddsaPublicKey;
-  /**
-   * Amount with fee.
-   */
-  amount_with_fee: AmountNbo;
-  /**
-   * Withdraw fee.
-   */
-  withdraw_fee: AmountNbo;
-  /**
-   * Hash of denomination public key.
-   */
-  h_denomination_pub: HashCode;
-  /**
-   * Hash of coin envelope.
-   */
-  h_coin_envelope: HashCode;
-}
-
-
-/**
- * Low-level handle to a WithdrawRequest signature structure.
- */
-export class WithdrawRequestPS extends SignatureStruct {
-  constructor(emsc: EmscEnvironment, w: WithdrawRequestPS_Args) {
-    super(emsc, w);
-  }
-
-  purpose() {
-    return SignaturePurpose.RESERVE_WITHDRAW;
-  }
-
-  fieldTypes() {
-    return [
-      ["reserve_pub", EddsaPublicKey],
-      ["amount_with_fee", AmountNbo],
-      ["withdraw_fee", AmountNbo],
-      ["h_denomination_pub", HashCode],
-      ["h_coin_envelope", HashCode],
-    ];
-  }
-}
-
-
-/**
- * Arguments for constructor or [[PaybackRequestPS]].
- */
-export interface PaybackRequestPS_args {
-  coin_pub: EddsaPublicKey;
-  h_denom_pub: HashCode;
-  coin_blind: RsaBlindingKeySecret;
-}
-
-
-/**
- * Low-level handle to a PaybackRequest signature structure.
- */
-export class PaybackRequestPS extends SignatureStruct {
-  constructor(emsc: EmscEnvironment, w: PaybackRequestPS_args) {
-    super(emsc, w);
-  }
-
-  purpose() {
-    return SignaturePurpose.WALLET_COIN_PAYBACK;
-  }
-
-  fieldTypes() {
-    return [
-      ["coin_pub", EddsaPublicKey],
-      ["h_denom_pub", HashCode],
-      ["coin_blind", RsaBlindingKeySecret],
-    ];
-  }
-}
-
-
-/**
- * Arguments for constructor of [[RefreshMeltCoinAffirmationPS]].
- */
-interface RefreshMeltCoinAffirmationPS_Args {
-  session_hash: HashCode;
-  amount_with_fee: AmountNbo;
-  melt_fee: AmountNbo;
-  coin_pub: EddsaPublicKey;
-}
-
-/**
- * Low-level handle to a RefreshMeltCoinAffirmationPS signature structure.
- */
-export class RefreshMeltCoinAffirmationPS extends SignatureStruct {
-  constructor(emsc: EmscEnvironment, w: RefreshMeltCoinAffirmationPS_Args) {
-    super(emsc, w);
-  }
-
-  purpose() {
-    return SignaturePurpose.WALLET_COIN_MELT;
-  }
-
-  fieldTypes() {
-    return [
-      ["session_hash", HashCode],
-      ["amount_with_fee", AmountNbo],
-      ["melt_fee", AmountNbo],
-      ["coin_pub", EddsaPublicKey],
-    ];
-  }
-}
-
-
-/**
- * Arguments for constructor of [[MasterWireFeePS]].
- */
-interface MasterWireFeePS_Args {
-  /**
-   * Hash of wire method.
-   */
-  h_wire_method: HashCode;
-  /**
-   * Start date.
-   */
-  start_date: AbsoluteTimeNbo;
-  /**
-   * End date.
-   */
-  end_date: AbsoluteTimeNbo;
-  /**
-   * Wire fee.
-   */
-  wire_fee: AmountNbo;
-  /**
-   * Closing fee.
-   */
-  closing_fee: AmountNbo;
-}
-
-
-/**
- * Low-level handle to a structure being signed over.
- */
-export class MasterWireFeePS extends SignatureStruct {
-  constructor(emsc: EmscEnvironment, w: MasterWireFeePS_Args) {
-    super(emsc, w);
-  }
-
-  purpose() {
-    return SignaturePurpose.MASTER_WIRE_FEES;
-  }
-
-  fieldTypes() {
-    return [
-      ["h_wire_method", HashCode],
-      ["start_date", AbsoluteTimeNbo],
-      ["end_date", AbsoluteTimeNbo],
-      ["wire_fee", AmountNbo],
-      ["closing_fee", AmountNbo],
-    ];
-  }
-}
-
-
-/**
- * Low-level handle to an absolute time in network byte order (NBO).
- */
-export class AbsoluteTimeNbo extends PackedArenaObject {
-  static fromTalerString(emsc: EmscEnvironment, s: string): AbsoluteTimeNbo {
-    const x = new AbsoluteTimeNbo(emsc);
-    x.alloc();
-    const r = /Date\(([0-9]+)\)/;
-    const m = r.exec(s);
-    if (!m || m.length !== 2) {
-      throw Error();
-    }
-    const n = parseInt(m[1], 10) * 1000000;
-    // XXX: This only works up to 54 bit numbers.
-    set64(emsc, x.nativePtr, n);
-    return x;
-  }
-
-  static fromStampSeconds(emsc: EmscEnvironment, stamp: number): AbsoluteTimeNbo {
-    const x = new AbsoluteTimeNbo(emsc);
-    x.alloc();
-    // XXX: This only works up to 54 bit numbers.
-    set64(emsc, x.nativePtr, stamp * 1000000);
-    return x;
-  }
-
-
-  size() {
-    return 8;
-  }
-}
-
-
-// XXX: This only works up to 54 bit numbers.
-function set64(emsc: EmscEnvironment, p: number, n: number) {
-  for (let i = 0; i < 8; ++i) {
-    emsc.lib.setValue(p + (7 - i), n & 0xFF, "i8");
-    n = Math.floor(n / 256);
-  }
-}
-
-// XXX: This only works up to 54 bit numbers.
-function set32(emsc: EmscEnvironment, p: number, n: number) {
-  for (let i = 0; i < 4; ++i) {
-    emsc.lib.setValue(p + (3 - i), n & 0xFF, "i8");
-    n = Math.floor(n / 256);
-  }
-}
-
-
-/**
- * Low-level handle to an unsigned 64-bit value.
- */
-export class UInt64 extends PackedArenaObject {
-  static fromNumber(emsc: EmscEnvironment, n: number): UInt64 {
-    const x = new UInt64(emsc);
-    x.alloc();
-    set64(emsc, x.nativePtr, n);
-    return x;
-  }
-
-  size() {
-    return 8;
-  }
-}
-
-
-/**
- * Low-level handle to an unsigned 32-bit value.
- */
-export class UInt32 extends PackedArenaObject {
-  static fromNumber(emsc: EmscEnvironment, n: number): UInt32 {
-    const x = new UInt32(emsc);
-    x.alloc();
-    set32(emsc, x.nativePtr, n);
-    return x;
-  }
-
-  size() {
-    return 4;
-  }
-}
-
-
-/**
- * Argument to the constructor of [[DepositRequestPS]].
- */
-export interface DepositRequestPS_Args {
-  /**
-   * Contract hash.
-   */
-  h_contract: HashCode;
-  /**
-   * Wire info hash.
-   */
-  h_wire: HashCode;
-  /**
-   * Timestamp.
-   */
-  timestamp: AbsoluteTimeNbo;
-  /**
-   * Refund deadline.
-   */
-  refund_deadline: AbsoluteTimeNbo;
-  /**
-   * Amount with fee.
-   */
-  amount_with_fee: AmountNbo;
-  /**
-   * Deposit fee.
-   */
-  deposit_fee: AmountNbo;
-  /**
-   * Merchant public key.
-   */
-  merchant: EddsaPublicKey;
-  /**
-   * Public key of the coin being deposited.
-   */
-  coin_pub: EddsaPublicKey;
-}
-
-
-/**
- * Low-level handle to a struct being signed over.
- */
-export class DepositRequestPS extends SignatureStruct {
-  constructor(emsc: EmscEnvironment, w: DepositRequestPS_Args) {
-    super(emsc, w);
-  }
-
-  purpose() {
-    return SignaturePurpose.WALLET_COIN_DEPOSIT;
-  }
-
-  fieldTypes() {
-    return [
-      ["h_contract", HashCode],
-      ["h_wire", HashCode],
-      ["timestamp", AbsoluteTimeNbo],
-      ["refund_deadline", AbsoluteTimeNbo],
-      ["amount_with_fee", AmountNbo],
-      ["deposit_fee", AmountNbo],
-      ["merchant", EddsaPublicKey],
-      ["coin_pub", EddsaPublicKey],
-    ];
-  }
-}
-
-
-interface CoinLinkSignaturePS_args {
-  h_denom_pub: HashCode;
-  old_coin_pub: EddsaPublicKey;
-  transfer_pub: EcdhePublicKey;
-  coin_envelope_hash: HashCode;
-}
-
-
-export class CoinLinkSignaturePS extends SignatureStruct {
-  constructor(emsc: EmscEnvironment, w: CoinLinkSignaturePS_args) {
-    super(emsc, w);
-  }
-
-  purpose() {
-    return SignaturePurpose.WALLET_COIN_LINK;
-  }
-
-  fieldTypes() {
-    return [
-      ["h_denom_pub", HashCode],
-      ["old_coin_pub", EddsaPublicKey],
-      ["transfer_pub", EcdhePublicKey],
-      ["coin_envelope_hash", HashCode],
-    ];
-  }
-}
-
-
-/**
- * Arguments for constuctor of [[DenominationKeyValidityPS]].
- */
-export interface DenominationKeyValidityPS_args {
-  master: EddsaPublicKey;
-  start: AbsoluteTimeNbo;
-  expire_withdraw: AbsoluteTimeNbo;
-  expire_spend: AbsoluteTimeNbo;
-  expire_legal: AbsoluteTimeNbo;
-  value: AmountNbo;
-  fee_withdraw: AmountNbo;
-  fee_deposit: AmountNbo;
-  fee_refresh: AmountNbo;
-  fee_refund: AmountNbo;
-  denom_hash: HashCode;
-}
-
-
-/**
- * Low-level handle to a structure being signed over.
- */
-export class DenominationKeyValidityPS extends SignatureStruct {
-  constructor(emsc: EmscEnvironment, w: DenominationKeyValidityPS_args) {
-    super(emsc, w);
-  }
-
-  purpose() {
-    return SignaturePurpose.MASTER_DENOMINATION_KEY_VALIDITY;
-  }
-
-  fieldTypes() {
-    return [
-      ["master", EddsaPublicKey],
-      ["start", AbsoluteTimeNbo],
-      ["expire_withdraw", AbsoluteTimeNbo],
-      ["expire_spend", AbsoluteTimeNbo],
-      ["expire_legal", AbsoluteTimeNbo],
-      ["value", AmountNbo],
-      ["fee_withdraw", AmountNbo],
-      ["fee_deposit", AmountNbo],
-      ["fee_refresh", AmountNbo],
-      ["fee_refund", AmountNbo],
-      ["denom_hash", HashCode],
-    ];
-  }
-}
-
-/**
- * Arguments to constructor of [[PaymentSignaturePS]].
- */
-export interface PaymentSignaturePS_args {
-  /**
-   * Contract hash.
-   */
-  contract_hash: HashCode;
-}
-
-
-/**
- * Low-level handle to a structure being signed over.
- */
-export class PaymentSignaturePS extends SignatureStruct {
-  constructor(emsc: EmscEnvironment, w: PaymentSignaturePS_args) {
-    super(emsc, w);
-  }
-
-  purpose() {
-    return SignaturePurpose.MERCHANT_PAYMENT_OK;
-  }
-
-  fieldTypes() {
-    return [
-      ["contract_hash", HashCode],
-    ];
-  }
-}
-
-
-/**
- * Low-level handle to an RsaPrivateKey.
- */
-export class RsaPrivateKey extends MallocArenaObject {
-  static fromCrock(emsc: EmscEnvironment, s: string): RsaPrivateKey {
-    return fromCrockDecoded(emsc, s, this, emsc.allocFuncs.rsa_private_key_decode);
-  }
-
-  static create(emsc: EmscEnvironment, bitLen: number, a?: Arena): RsaPrivateKey {
-    const obj = new RsaPrivateKey(emsc, a);
-    obj.nativePtr = emsc.allocFuncs.rsa_private_key_create(bitLen);
-    return obj;
-  }
-
-  toCrock() {
-    return this.encode().toCrock();
-  }
-
-
-  getPublicKey(a?: Arena): RsaPublicKey {
-    const obj = new RsaPublicKey(this.emsc, a);
-    obj.nativePtr = this.emsc.allocFuncs.rsa_private_key_get_public(this.nativePtr);
-    return obj;
-  }
-
-  destroy() {
-    this.emsc.funcs.rsa_public_key_free(this.nativePtr);
-    this.nativePtr = 0;
-  }
-
-  encode(arena?: Arena): ByteArray {
-    return encode(this, this.emsc.allocFuncs.rsa_private_key_encode);
-  }
-}
-
-
-/**
- * Low-level handle to an RsaPublicKey.
- */
-export class RsaPublicKey extends MallocArenaObject {
-  static fromCrock(emsc: EmscEnvironment, s: string): RsaPublicKey {
-    return fromCrockDecoded(emsc, s, this, emsc.allocFuncs.rsa_public_key_decode);
-  }
-
-  toCrock() {
-    return this.encode().toCrock();
-  }
-
-  destroy() {
-    this.emsc.funcs.rsa_public_key_free(this.nativePtr);
-    this.nativePtr = 0;
-  }
-
-  encode(arena?: Arena): ByteArray {
-    return encode(this, this.emsc.allocFuncs.rsa_public_key_encode);
-  }
-}
-
-
-/**
- * Low-level handle to an EddsaSignature.
- */
-export class EddsaSignature extends PackedArenaObject {
-  size() {
-    return 64;
-  }
-  static fromCrock(emsc: EmscEnvironment, s: string): EddsaSignature {
-    return fromCrock(emsc, s, this);
-  }
-}
-
-
-/**
- * Low-level handle to an RsaSignature.
- */
-export class RsaSignature extends MallocArenaObject {
-  static fromCrock(emsc: EmscEnvironment, s: string, a?: Arena) {
-    return fromCrockDecoded(emsc, s, this, emsc.allocFuncs.rsa_signature_decode);
-  }
-
-  encode(arena?: Arena): ByteArray {
-    return encode(this, this.emsc.allocFuncs.rsa_signature_encode);
-  }
-
-  destroy() {
-    this.emsc.funcs.rsa_signature_free(this.nativePtr);
-    this.nativePtr = 0;
-  }
-}
-
-
-/**
- * Blind a value so it can be blindly signed.
- */
-export function rsaBlind(hashCode: HashCode,
-                         blindingKey: RsaBlindingKeySecret,
-                         pkey: RsaPublicKey,
-                         arena?: Arena): ByteArray|null {
-  const emsc: EmscEnvironment = hashCode.emsc;
-  const buf_ptr_out = emsc.allocFuncs.malloc(PTR_SIZE);
-  const buf_size_out = emsc.allocFuncs.malloc(PTR_SIZE);
-  const res = emsc.allocFuncs.rsa_blind(hashCode.nativePtr,
-                                          blindingKey.nativePtr,
-                                          pkey.nativePtr,
-                                          buf_ptr_out,
-                                          buf_size_out);
-  const buf_ptr = emsc.lib.getValue(buf_ptr_out, "*");
-  const buf_size = emsc.lib.getValue(buf_size_out, "*");
-  emsc.funcs.free(buf_ptr_out);
-  emsc.funcs.free(buf_size_out);
-  if (res !== GNUNET_OK) {
-    // malicious key
-    return null;
-  }
-  return new ByteArray(emsc, buf_size, buf_ptr, arena);
-}
-
-
-/**
- * Sign data using EdDSA.
- */
-export function eddsaSign(purpose: EccSignaturePurpose,
-                          priv: EddsaPrivateKey,
-                          a?: Arena): EddsaSignature {
-  const sig = new EddsaSignature(purpose.emsc, a);
-  sig.alloc();
-  const res = purpose.emsc.funcs.eddsa_sign(priv.nativePtr, purpose.nativePtr, sig.nativePtr);
-  if (res < 1) {
-    throw Error("EdDSA signing failed");
-  }
-  return sig;
-}
-
-
-/**
- * Verify EdDSA-signed data.
- */
-export function eddsaVerify(purposeNum: number,
-                            verify: EccSignaturePurpose,
-                            sig: EddsaSignature,
-                            pub: EddsaPublicKey,
-                            a?: Arena): boolean {
-  const r = verify.emsc.funcs.eddsa_verify(purposeNum,
-                                      verify.nativePtr,
-                                      sig.nativePtr,
-                                      pub.nativePtr);
-  return r === GNUNET_OK;
-}
-
-
-export function rsaVerify(h: HashCode,
-                          sig: RsaSignature,
-                          pub: RsaPublicKey) {
-  const r = h.emsc.funcs.rsa_verify(h.nativePtr,
-                                    sig.nativePtr,
-                                    pub.nativePtr);
-  return r === GNUNET_OK;
-}
-
-
-/**
- * Unblind a blindly signed value.
- */
-export function rsaUnblind(sig: RsaSignature,
-                           bk: RsaBlindingKeySecret,
-                           pk: RsaPublicKey,
-                           a?: Arena): RsaSignature {
-  const x = new RsaSignature(sig.emsc, a);
-  x.nativePtr = sig.emsc.allocFuncs.rsa_unblind(sig.nativePtr,
-                                              bk.nativePtr,
-                                              pk.nativePtr);
-  return x;
-}
-
-
-type TransferSecretP = HashCode;
-
-/**
- * A fresh coin generated from a sed.
- */
-export interface FreshCoin {
-  /**
-   * The coin's private key.
-   */
-  priv: EddsaPrivateKey;
-  /**
-   * The blinding key to use for withdrawal.
-   */
-  blindingKey: RsaBlindingKeySecret;
-}
-
-/**
- * Diffie-Hellman operation between an ECDHE private key
- * and an EdDSA public key.
- */
-export function ecdhEddsa(priv: EcdhePrivateKey,
-                          pub: EddsaPublicKey): HashCode {
-  const h = new HashCode(priv.emsc);
-  h.alloc();
-  const res = priv.emsc.funcs.ecdh_eddsa(priv.nativePtr, pub.nativePtr, h.nativePtr);
-  if (res !== GNUNET_OK) {
-    throw Error("ecdh_eddsa failed");
-  }
-  return h;
-}
-
-export function rsaSignBlinded(priv: RsaPrivateKey,
-                               msg: ByteArray): RsaSignature {
-  const sig = new RsaSignature(priv.emsc);
-  sig.nativePtr = priv.emsc.allocFuncs.rsa_sign_blinded (priv.nativePtr,
-                                                      msg.nativePtr,
-                                                      msg.size());
-  return sig;
-}
-
-
-
-/**
- * Derive a fresh coin from the given seed.  Used during refreshing.
- */
-export function setupFreshCoin(secretSeed: TransferSecretP,
-                               coinIndex: number): FreshCoin {
-  const emsc: EmscEnvironment = secretSeed.emsc; 
-  const priv = new EddsaPrivateKey(emsc);
-  priv.isWeak = true;
-  const blindingKey = new RsaBlindingKeySecret(emsc);
-  blindingKey.isWeak = true;
-  const buf = new ByteArray(emsc, priv.size() + blindingKey.size());
-
-  emsc.funcs.setup_fresh_coin(secretSeed.nativePtr, coinIndex, buf.nativePtr);
-
-  priv.nativePtr = buf.nativePtr;
-  blindingKey.nativePtr = buf.nativePtr + priv.size();
-
-  return { priv, blindingKey };
-}