1.1 --- a/libraries/moonhash/moonhash.c	Tue Aug 15 21:00:51 2017 +0200
     1.2 +++ b/libraries/moonhash/moonhash.c	Wed Aug 16 00:31:11 2017 +0200
     1.3 @@ -42,18 +42,59 @@
     1.4    return moonhash_sha3(L, FIPS202_SHA3_512, 512/8);
     1.5  }
     1.6  
     1.7 -int moonhash_shake(lua_State *L, moonhash_shake_fptr shakefunc, int len) {
     1.8 +int moonhash_shake(lua_State *L, int R, lua_Integer deflen) {
     1.9    const char *input;
    1.10    size_t inputlen;
    1.11 -  unsigned char output[len];
    1.12 +  lua_Integer outputlen;
    1.13 +  const char *alphabet;
    1.14 +  size_t alen;
    1.15 +  int abits = 0;
    1.16 +  uint8_t s[200];
    1.17 +  luaL_Buffer luabuf;
    1.18 +  uint8_t *output;
    1.19 +  int readpos = 0;
    1.20 +  lua_Integer writepos = 0;
    1.21 +  int rbits = 0;
    1.22 +  int rbuf = 0;
    1.23 +  int rvalue;
    1.24    input = luaL_checklstring(L, 1, &inputlen);
    1.25 -  shakefunc((const uint8_t *)input, inputlen, output, len);
    1.26 -  moonhash_push_hex(L, output, len);
    1.27 +  outputlen = luaL_optinteger(L, 2, deflen);
    1.28 +  alphabet = luaL_optlstring(L, 3, "0123456789abcdef", &alen);
    1.29 +  luaL_argcheck(L, alen>1, 3, "too few characters in alphabet");
    1.30 +  {
    1.31 +    size_t t = alen-1;
    1.32 +    while (t) {
    1.33 +      abits++;
    1.34 +      if (abits > 8) luaL_argcheck(L, 0, 3, "too many characters in alphabet");
    1.35 +      t >>= 1;
    1.36 +    }
    1.37 +  }
    1.38 +  KeccakF1600Init(s, R, (const uint8_t *)input, inputlen, 0x1F);
    1.39 +  output = (uint8_t *)luaL_buffinitsize(L, &luabuf, outputlen);
    1.40 +  while (writepos < outputlen) {
    1.41 +    if (rbits < abits) {
    1.42 +      if (readpos == R) {
    1.43 +        KeccakF1600(s);
    1.44 +        readpos = 0;
    1.45 +      }
    1.46 +      rbuf = (rbuf << 8) | s[readpos++];
    1.47 +      rbits += 8;
    1.48 +    }
    1.49 +    rbits -= abits;
    1.50 +    rvalue = rbuf >> rbits;
    1.51 +    rbuf &= (1<<rbits)-1;
    1.52 +    if (rvalue < alen) output[writepos++] = alphabet[rvalue];
    1.53 +  }
    1.54 +  luaL_pushresultsize(&luabuf, outputlen);
    1.55    return 1;
    1.56  }
    1.57  
    1.58 -int moonhash_shake128_128(lua_State *L) {
    1.59 -  return moonhash_shake(L, FIPS202_SHAKE128, 128/8);
    1.60 +int moonhash_shake128(lua_State *L) {
    1.61 +  return moonhash_shake(L, (1600-2*128)/8, 128/4);
    1.62 +}
    1.63 +
    1.64 +int moonhash_shake256(lua_State *L) {
    1.65 +  return moonhash_shake(L, (1600-2*256)/8, 256/4);
    1.66  }
    1.67  
    1.68  static const struct luaL_Reg moonhash_module_functions[] = {
    1.69 @@ -61,7 +102,8 @@
    1.70   {"sha3_256", moonhash_sha3_256},
    1.71   {"sha3_384", moonhash_sha3_384},
    1.72   {"sha3_512", moonhash_sha3_512},
    1.73 - {"shake128_128", moonhash_shake128_128},
    1.74 + {"shake128", moonhash_shake128},
    1.75 + {"shake256", moonhash_shake256},
    1.76   {NULL, NULL}
    1.77  };
    1.78