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xahaud/src/libxrpl/basics/base64.cpp
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//------------------------------------------------------------------------------
/*
This file is part of rippled: https://github.com/ripple/rippled
Copyright (c) 2012-2018 Ripple Labs Inc.
Permission to use, copy, modify, and/or distribute this software for any
purpose with or without fee is hereby granted, provided that the above
copyright notice and this permission notice appear in all copies.
THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
ANY SPECIAL , DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
//==============================================================================
//
// Copyright (c) 2013-2017 Vinnie Falco (vinnie dot falco at gmail dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
/*
Portions from http://www.adp-gmbh.ch/cpp/common/base64.html
Copyright notice:
base64.cpp and base64.h
Copyright (C) 2004-2008 René Nyffenegger
This source code is provided 'as-is', without any express or implied
warranty. In no event will the author be held liable for any damages
arising from the use of this software.
Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute it
freely, subject to the following restrictions:
1. The origin of this source code must not be misrepresented; you must not
claim that you wrote the original source code. If you use this source code
in a product, an acknowledgment in the product documentation would be
appreciated but is not required.
2. Altered source versions must be plainly marked as such, and must not be
misrepresented as being the original source code.
3. This notice may not be removed or altered from any source distribution.
René Nyffenegger rene.nyffenegger@adp-gmbh.ch
*/
#include <ripple/basics/base64.h>
#include <cctype>
#include <utility>
namespace ripple {
namespace base64 {
inline char const*
get_alphabet()
{
static char constexpr tab[] = {
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"};
return &tab[0];
}
inline signed char const*
get_inverse()
{
static signed char constexpr tab[] = {
-1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, // 0-15
-1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, // 16-31
-1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, 62, -1, -1, -1, 63, // 32-47
52, 53, 54, 55, 56, 57, 58, 59,
60, 61, -1, -1, -1, -1, -1, -1, // 48-63
-1, 0, 1, 2, 3, 4, 5, 6,
7, 8, 9, 10, 11, 12, 13, 14, // 64-79
15, 16, 17, 18, 19, 20, 21, 22,
23, 24, 25, -1, -1, -1, -1, -1, // 80-95
-1, 26, 27, 28, 29, 30, 31, 32,
33, 34, 35, 36, 37, 38, 39, 40, // 96-111
41, 42, 43, 44, 45, 46, 47, 48,
49, 50, 51, -1, -1, -1, -1, -1, // 112-127
-1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, // 128-143
-1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, // 144-159
-1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, // 160-175
-1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, // 176-191
-1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, // 192-207
-1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, // 208-223
-1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, // 224-239
-1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1 // 240-255
};
return &tab[0];
}
/// Returns max chars needed to encode a base64 string
inline std::size_t constexpr encoded_size(std::size_t n)
{
return 4 * ((n + 2) / 3);
}
/// Returns max bytes needed to decode a base64 string
inline std::size_t constexpr decoded_size(std::size_t n)
{
return ((n / 4) * 3) + 2;
}
/** Encode a series of octets as a padded, base64 string.
The resulting string will not be null terminated.
@par Requires
The memory pointed to by `out` points to valid memory
of at least `encoded_size(len)` bytes.
@return The number of characters written to `out`. This
will exclude any null termination.
*/
std::size_t
encode(void* dest, void const* src, std::size_t len)
{
char* out = static_cast<char*>(dest);
char const* in = static_cast<char const*>(src);
auto const tab = base64::get_alphabet();
for (auto n = len / 3; n--;)
{
*out++ = tab[(in[0] & 0xfc) >> 2];
*out++ = tab[((in[0] & 0x03) << 4) + ((in[1] & 0xf0) >> 4)];
*out++ = tab[((in[2] & 0xc0) >> 6) + ((in[1] & 0x0f) << 2)];
*out++ = tab[in[2] & 0x3f];
in += 3;
}
switch (len % 3)
{
case 2:
*out++ = tab[(in[0] & 0xfc) >> 2];
*out++ = tab[((in[0] & 0x03) << 4) + ((in[1] & 0xf0) >> 4)];
*out++ = tab[(in[1] & 0x0f) << 2];
*out++ = '=';
break;
case 1:
*out++ = tab[(in[0] & 0xfc) >> 2];
*out++ = tab[((in[0] & 0x03) << 4)];
*out++ = '=';
*out++ = '=';
break;
case 0:
break;
}
return out - static_cast<char*>(dest);
}
/** Decode a padded base64 string into a series of octets.
@par Requires
The memory pointed to by `out` points to valid memory
of at least `decoded_size(len)` bytes.
@return The number of octets written to `out`, and
the number of characters read from the input string,
expressed as a pair.
*/
std::pair<std::size_t, std::size_t>
decode(void* dest, char const* src, std::size_t len)
{
char* out = static_cast<char*>(dest);
auto in = reinterpret_cast<unsigned char const*>(src);
unsigned char c3[3]{}, c4[4]{};
int i = 0;
int j = 0;
auto const inverse = base64::get_inverse();
while (len-- && *in != '=')
{
auto const v = inverse[*in];
if (v == -1)
break;
++in;
c4[i] = v;
if (++i == 4)
{
c3[0] = (c4[0] << 2) + ((c4[1] & 0x30) >> 4);
c3[1] = ((c4[1] & 0xf) << 4) + ((c4[2] & 0x3c) >> 2);
c3[2] = ((c4[2] & 0x3) << 6) + c4[3];
for (i = 0; i < 3; i++)
*out++ = c3[i];
i = 0;
}
}
if (i)
{
c3[0] = (c4[0] << 2) + ((c4[1] & 0x30) >> 4);
c3[1] = ((c4[1] & 0xf) << 4) + ((c4[2] & 0x3c) >> 2);
c3[2] = ((c4[2] & 0x3) << 6) + c4[3];
for (j = 0; j < i - 1; j++)
*out++ = c3[j];
}
return {
out - static_cast<char*>(dest),
in - reinterpret_cast<unsigned char const*>(src)};
}
} // namespace base64
std::string
base64_encode(std::uint8_t const* data, std::size_t len)
{
std::string dest;
dest.resize(base64::encoded_size(len));
dest.resize(base64::encode(&dest[0], data, len));
return dest;
}
std::string
base64_decode(std::string_view data)
{
std::string dest;
dest.resize(base64::decoded_size(data.size()));
auto const result = base64::decode(&dest[0], data.data(), data.size());
dest.resize(result.first);
return dest;
}
} // namespace ripple