encode/base: add initial base64 experiments
This commit is contained in:
parent
02d3b4dd64
commit
e437913746
@ -203,6 +203,8 @@ list (
|
|||||||
debug.cpp
|
debug.cpp
|
||||||
debug.hpp
|
debug.hpp
|
||||||
debug.ipp
|
debug.ipp
|
||||||
|
encode/base.cpp
|
||||||
|
encode/base.hpp
|
||||||
endian.cpp
|
endian.cpp
|
||||||
endian.hpp
|
endian.hpp
|
||||||
exe.hpp
|
exe.hpp
|
||||||
@ -498,6 +500,7 @@ if (TESTS)
|
|||||||
crypto/tea
|
crypto/tea
|
||||||
crypto/xtea
|
crypto/xtea
|
||||||
crypto/xxtea
|
crypto/xxtea
|
||||||
|
encode/base
|
||||||
endian
|
endian
|
||||||
exe
|
exe
|
||||||
extent
|
extent
|
||||||
|
|||||||
18
encode/base.cpp
Normal file
18
encode/base.cpp
Normal file
@ -0,0 +1,18 @@
|
|||||||
|
/*
|
||||||
|
* Licensed under the Apache License, Version 2.0 (the "License");
|
||||||
|
* you may not use this file except in compliance with the License.
|
||||||
|
* You may obtain a copy of the License at
|
||||||
|
*
|
||||||
|
* http://www.apache.org/licenses/LICENSE-2.0
|
||||||
|
*
|
||||||
|
* Unless required by applicable law or agreed to in writing, software
|
||||||
|
* distributed under the License is distributed on an "AS IS" BASIS,
|
||||||
|
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||||||
|
* See the License for the specific language governing permissions and
|
||||||
|
* limitations under the License.
|
||||||
|
*
|
||||||
|
* Copyright 2017 Danny Robson <danny@nerdcruft.net>
|
||||||
|
*/
|
||||||
|
|
||||||
|
#include "base.hpp"
|
||||||
|
|
||||||
247
encode/base.hpp
Normal file
247
encode/base.hpp
Normal file
@ -0,0 +1,247 @@
|
|||||||
|
/*
|
||||||
|
* Licensed under the Apache License, Version 2.0 (the "License");
|
||||||
|
* you may not use this file except in compliance with the License.
|
||||||
|
* You may obtain a copy of the License at
|
||||||
|
*
|
||||||
|
* http://www.apache.org/licenses/LICENSE-2.0
|
||||||
|
*
|
||||||
|
* Unless required by applicable law or agreed to in writing, software
|
||||||
|
* distributed under the License is distributed on an "AS IS" BASIS,
|
||||||
|
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||||||
|
* See the License for the specific language governing permissions and
|
||||||
|
* limitations under the License.
|
||||||
|
*
|
||||||
|
* Copyright 2017 Danny Robson <danny@nerdcruft.net>
|
||||||
|
*/
|
||||||
|
|
||||||
|
#ifndef CRUFT_UTIL_BASE64_HPP
|
||||||
|
#define CRUFT_UTIL_BASE64_HPP
|
||||||
|
|
||||||
|
#include "../view.hpp"
|
||||||
|
|
||||||
|
#include "../debug.hpp"
|
||||||
|
|
||||||
|
#include <cstdint>
|
||||||
|
#include <array>
|
||||||
|
|
||||||
|
|
||||||
|
namespace util::encode {
|
||||||
|
///////////////////////////////////////////////////////////////////////////
|
||||||
|
template <int Size>
|
||||||
|
struct alphabet {
|
||||||
|
static const char enc[Size];
|
||||||
|
static const uint8_t dec[256];
|
||||||
|
};
|
||||||
|
|
||||||
|
|
||||||
|
///////////////////////////////////////////////////////////////////////////
|
||||||
|
template <>
|
||||||
|
const char alphabet<64>::enc[64] = {
|
||||||
|
'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M',
|
||||||
|
'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
|
||||||
|
'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm',
|
||||||
|
'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
|
||||||
|
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/',
|
||||||
|
};
|
||||||
|
|
||||||
|
|
||||||
|
//-------------------------------------------------------------------------
|
||||||
|
template <>
|
||||||
|
const uint8_t alphabet<64>::dec[256] = {
|
||||||
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
||||||
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
||||||
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0x3E, 0, 0, 0, 0x3F,
|
||||||
|
0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B, 0x3C, 0x3D, 0, 0, 0, 0, 0, 0,
|
||||||
|
0, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E,
|
||||||
|
0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0, 0, 0, 0, 0,
|
||||||
|
0, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28,
|
||||||
|
0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x32, 0x33, 0, 0, 0, 0, 0,
|
||||||
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
||||||
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
||||||
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
||||||
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
||||||
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
||||||
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
||||||
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
||||||
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
||||||
|
};
|
||||||
|
|
||||||
|
|
||||||
|
///////////////////////////////////////////////////////////////////////////
|
||||||
|
template <>
|
||||||
|
const char alphabet<32>::enc[32] {
|
||||||
|
'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M',
|
||||||
|
'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
|
||||||
|
'2', '3', '4', '5', '6', '7',
|
||||||
|
};
|
||||||
|
|
||||||
|
|
||||||
|
//-------------------------------------------------------------------------
|
||||||
|
template <>
|
||||||
|
const uint8_t alphabet<32>::dec[256] = {
|
||||||
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
||||||
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
||||||
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
||||||
|
0, 0, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 0, 0, 0, 0, 0, 0, 0, 0,
|
||||||
|
0, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e,
|
||||||
|
0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0, 0, 0, 0, 0,
|
||||||
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
||||||
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
||||||
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
||||||
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
||||||
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
||||||
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
||||||
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
||||||
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
||||||
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
||||||
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
|
||||||
|
};
|
||||||
|
|
||||||
|
|
||||||
|
///////////////////////////////////////////////////////////////////////////
|
||||||
|
template <>
|
||||||
|
const char alphabet<16>::enc[16] {
|
||||||
|
'0', '1', '2', '3', '4', '5', '6', '7',
|
||||||
|
'8', '9', 'A', 'B', 'C', 'D', 'E', 'F',
|
||||||
|
};
|
||||||
|
|
||||||
|
template <>
|
||||||
|
const uint8_t alphabet<16>::dec[256] = {
|
||||||
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
||||||
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
||||||
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
||||||
|
0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0, 0, 0, 0, 0, 0,
|
||||||
|
0, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
||||||
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
||||||
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
||||||
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
||||||
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
||||||
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
||||||
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
||||||
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
||||||
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
||||||
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
||||||
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
||||||
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
|
||||||
|
};
|
||||||
|
|
||||||
|
|
||||||
|
//-------------------------------------------------------------------------
|
||||||
|
template <int Size> constexpr auto enc_v = alphabet<Size>::enc;
|
||||||
|
template <int Size> constexpr auto dec_v = alphabet<Size>::dec;
|
||||||
|
|
||||||
|
|
||||||
|
///////////////////////////////////////////////////////////////////////////
|
||||||
|
/// rfc4648 base16, base32, and base64 encoding
|
||||||
|
template <int Size>
|
||||||
|
struct base {
|
||||||
|
static constexpr auto symbol_bits = log2 (Size);
|
||||||
|
static constexpr auto group_bits = std::lcm (symbol_bits, 8);
|
||||||
|
static constexpr auto group_symbols = group_bits / symbol_bits;
|
||||||
|
static constexpr auto group_bytes = group_bits / 8;
|
||||||
|
|
||||||
|
static constexpr uint_fast32_t mask = (1<<symbol_bits)-1;
|
||||||
|
|
||||||
|
|
||||||
|
template <typename InputT, typename OutputT>
|
||||||
|
static OutputT
|
||||||
|
encode (OutputT dst, const util::view<InputT> src)
|
||||||
|
{
|
||||||
|
// convert whole groups of symbols while we have enough bytes remaining
|
||||||
|
auto cursor = std::cbegin (src);
|
||||||
|
for (size_t i = 0, last = std::size (src) / group_bytes; i != last; ++i) {
|
||||||
|
auto tally = std::accumulate (
|
||||||
|
cursor, cursor + group_bytes,
|
||||||
|
uint_fast32_t {0},
|
||||||
|
[] (auto a, auto b) { return a << 8 | b; }
|
||||||
|
);
|
||||||
|
|
||||||
|
cursor += group_bytes;
|
||||||
|
|
||||||
|
for (int j = group_symbols - 1; j >= 0; --j)
|
||||||
|
*dst++ = enc_v<Size>[tally >> (j * symbol_bits) & mask];
|
||||||
|
}
|
||||||
|
|
||||||
|
// we don't need to pad the output so we can early exit
|
||||||
|
if (cursor == std::cend (src))
|
||||||
|
return dst;
|
||||||
|
|
||||||
|
// accumulate the remaining bits and pad to a multiple of the
|
||||||
|
// output group length
|
||||||
|
auto tally = std::accumulate (
|
||||||
|
cursor,
|
||||||
|
std::cend (src),
|
||||||
|
uint_fast32_t {0},
|
||||||
|
[] (auto a, auto b) { return a << 8 | b; }
|
||||||
|
);
|
||||||
|
|
||||||
|
auto input_remain = std::cend (src) - cursor;
|
||||||
|
tally <<= symbol_bits - input_remain * 8 % symbol_bits;
|
||||||
|
|
||||||
|
// write each of the remaining symbols
|
||||||
|
auto output_remain = (input_remain * 8 + symbol_bits - 1) / symbol_bits;
|
||||||
|
for (auto i = output_remain - 1; i >= 0; --i)
|
||||||
|
*dst++ = enc_v<Size>[tally >> (i * symbol_bits) & mask];
|
||||||
|
|
||||||
|
// pad the output to the symbol group size with '=' characters
|
||||||
|
auto fill = (group_bytes - input_remain) * 8 / symbol_bits;
|
||||||
|
return std::fill_n (dst, fill, '=');
|
||||||
|
}
|
||||||
|
|
||||||
|
|
||||||
|
//---------------------------------------------------------------------
|
||||||
|
template <typename InputT, typename OutputT>
|
||||||
|
static OutputT
|
||||||
|
decode (OutputT dst, util::view<InputT> src)
|
||||||
|
{
|
||||||
|
if (src.empty ())
|
||||||
|
return dst;
|
||||||
|
|
||||||
|
if (src.size () % group_symbols)
|
||||||
|
throw std::invalid_argument ("base-encoded strings must be a proper multiple of symbols");
|
||||||
|
|
||||||
|
union {
|
||||||
|
uint_fast32_t num;
|
||||||
|
uint8_t bytes[group_bytes];
|
||||||
|
};
|
||||||
|
|
||||||
|
const bool padded = src.end ()[-1] == '=';
|
||||||
|
auto cursor = std::cbegin (src);
|
||||||
|
for (size_t i = 0, last = std::size (src) / group_symbols - padded?1:0;
|
||||||
|
i != last;
|
||||||
|
++i)
|
||||||
|
{
|
||||||
|
num = std::accumulate (
|
||||||
|
cursor, cursor + group_symbols,
|
||||||
|
uint_fast32_t {0},
|
||||||
|
[] (auto a, auto b) { return a << symbol_bits | dec_v<Size>[b]; }
|
||||||
|
);
|
||||||
|
|
||||||
|
cursor += group_symbols;
|
||||||
|
|
||||||
|
dst = std::copy (std::crbegin (bytes), std::crend (bytes), dst);
|
||||||
|
}
|
||||||
|
|
||||||
|
if (cursor != std::end (src)) {
|
||||||
|
auto last = std::find (cursor, std::cend (src), '=');
|
||||||
|
num = std::accumulate (
|
||||||
|
cursor, last,
|
||||||
|
uint_fast32_t{0},
|
||||||
|
[] (auto a, auto b) { return a << symbol_bits | dec_v<Size>[b]; }
|
||||||
|
);
|
||||||
|
|
||||||
|
auto symbols = last - cursor;
|
||||||
|
auto bits = symbols * symbol_bits;
|
||||||
|
auto shift = bits%8;
|
||||||
|
num >>= shift;
|
||||||
|
|
||||||
|
for (auto i = bits / 8; i; )
|
||||||
|
*dst++ = bytes[--i];
|
||||||
|
}
|
||||||
|
|
||||||
|
return dst;
|
||||||
|
}
|
||||||
|
};
|
||||||
|
};
|
||||||
|
|
||||||
|
#endif
|
||||||
91
test/encode/base.cpp
Normal file
91
test/encode/base.cpp
Normal file
@ -0,0 +1,91 @@
|
|||||||
|
#include "../../tap.hpp"
|
||||||
|
|
||||||
|
#include "../../encode/base.hpp"
|
||||||
|
#include "../../iterator.hpp"
|
||||||
|
|
||||||
|
|
||||||
|
///////////////////////////////////////////////////////////////////////////////
|
||||||
|
static constexpr char input[] = "foobar";
|
||||||
|
|
||||||
|
|
||||||
|
//-----------------------------------------------------------------------------
|
||||||
|
// test vectors from rfc4648
|
||||||
|
template <int Size>
|
||||||
|
struct output { static const char *value[std::size (input)]; };
|
||||||
|
|
||||||
|
//-----------------------------------------------------------------------------
|
||||||
|
template <>
|
||||||
|
const char* output<64>::value[] = {
|
||||||
|
"", "Zg==", "Zm8=", "Zm9v", "Zm9vYg==", "Zm9vYmE=", "Zm9vYmFy",
|
||||||
|
};
|
||||||
|
|
||||||
|
|
||||||
|
template <>
|
||||||
|
const char* output<32>::value[] {
|
||||||
|
"", "MY======", "MZXQ====", "MZXW6===", "MZXW6YQ=", "MZXW6YTB", "MZXW6YTBOI======"
|
||||||
|
};
|
||||||
|
|
||||||
|
|
||||||
|
#if 0
|
||||||
|
template <>
|
||||||
|
const char* output<32h>::value[] {
|
||||||
|
"", "CO======", "CPNG====", "CPNMU===", "CPNMUOG=", "CPNMUOJ1", "CPNMUOJ1E8======",
|
||||||
|
}
|
||||||
|
#endif
|
||||||
|
|
||||||
|
|
||||||
|
//-----------------------------------------------------------------------------
|
||||||
|
template <>
|
||||||
|
const char *output<16>::value[] = {
|
||||||
|
"", "66", "666F", "666F6F", "666F6F62", "666F6F6261", "666F6F626172"
|
||||||
|
};
|
||||||
|
|
||||||
|
|
||||||
|
//-----------------------------------------------------------------------------
|
||||||
|
template <int Size>
|
||||||
|
const auto output_v = output<Size>::value;
|
||||||
|
|
||||||
|
|
||||||
|
///////////////////////////////////////////////////////////////////////////////
|
||||||
|
template <int Size>
|
||||||
|
void
|
||||||
|
test_size (util::TAP::logger &tap)
|
||||||
|
{
|
||||||
|
for (unsigned i = 0; i < std::size (input); ++i) {
|
||||||
|
const auto fragment = util::make_view (input, input + i);
|
||||||
|
|
||||||
|
std::string encoded;
|
||||||
|
|
||||||
|
util::encode::base<Size>::encode (
|
||||||
|
std::back_inserter (encoded),
|
||||||
|
fragment
|
||||||
|
);
|
||||||
|
|
||||||
|
tap.expect_eq (encoded, output_v<Size>[i],
|
||||||
|
"%! character base%! encode; '%!' is '%!'", i, Size, encoded, output_v<Size>[i]
|
||||||
|
);
|
||||||
|
|
||||||
|
|
||||||
|
std::string decoded;
|
||||||
|
util::encode::base<Size>::decode (
|
||||||
|
std::back_inserter (decoded),
|
||||||
|
util::make_view (encoded)
|
||||||
|
);
|
||||||
|
|
||||||
|
tap.expect_eq (decoded, fragment, "%! character base%! decode, '%!'", i, Size, decoded);
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
|
||||||
|
///////////////////////////////////////////////////////////////////////////////
|
||||||
|
int
|
||||||
|
main ()
|
||||||
|
{
|
||||||
|
util::TAP::logger tap;
|
||||||
|
|
||||||
|
test_size<16> (tap);
|
||||||
|
test_size<32> (tap);
|
||||||
|
test_size<64> (tap);
|
||||||
|
|
||||||
|
return tap.status ();
|
||||||
|
}
|
||||||
Loading…
Reference in New Issue
Block a user