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Diffstat (limited to 'external/cppcodec/detail/base64.hpp')
| -rw-r--r-- | external/cppcodec/detail/base64.hpp | 132 |
1 files changed, 132 insertions, 0 deletions
diff --git a/external/cppcodec/detail/base64.hpp b/external/cppcodec/detail/base64.hpp new file mode 100644 index 0000000..b6db6d7 --- /dev/null +++ b/external/cppcodec/detail/base64.hpp @@ -0,0 +1,132 @@ +/** + * Copyright (C) 2015 Topology LP + * Copyright (C) 2013 Adam Rudd (bit calculations) + * Copyright (C) 2018 Jakob Petsovits + * All rights reserved. + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to + * deal in the Software without restriction, including without limitation the + * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or + * sell copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS + * IN THE SOFTWARE. + * + * Bit calculations adapted from https://github.com/adamvr/arduino-base64, + * commit 999595783185a0afcba156d7276dfeaa9cb5382f. + */ + +#ifndef CPPCODEC_DETAIL_BASE64 +#define CPPCODEC_DETAIL_BASE64 + +#include <stdexcept> +#include <stdint.h> + +#include "../data/access.hpp" +#include "../parse_error.hpp" +#include "config.hpp" +#include "stream_codec.hpp" + +namespace cppcodec { +namespace detail { + +template <typename CodecVariant> +class base64 : public CodecVariant::template codec_impl<base64<CodecVariant>> +{ +public: + static inline constexpr uint8_t binary_block_size() { return 3; } + static inline constexpr uint8_t encoded_block_size() { return 4; } + + static CPPCODEC_ALWAYS_INLINE constexpr uint8_t num_encoded_tail_symbols(uint8_t num_bytes) + { + return (num_bytes == 1) ? 2 // 2 symbols, 2 padding characters + : (num_bytes == 2) ? 3 // 3 symbols, 1 padding character + : throw std::domain_error("invalid number of bytes in a tail block"); + } + + template <uint8_t I> + static CPPCODEC_ALWAYS_INLINE constexpr uint8_t index( + const uint8_t* b /*binary block*/) noexcept + { + static_assert(I >= 0 && I < encoded_block_size(), + "invalid encoding symbol index in a block"); + + return (I == 0) ? (b[0] >> 2) // first 6 bits + : (I == 1) ? (((b[0] & 0x3) << 4) | (b[1] >> 4)) + : (I == 2) ? (((b[1] & 0xF) << 2) | (b[2] >> 6)) + : /*I == 3*/ (b[2] & 0x3F); // last 6 bits + } + + template <bool B> + using uint8_if = typename std::enable_if<B, uint8_t>::type; + + template <uint8_t I> + static CPPCODEC_ALWAYS_INLINE constexpr uint8_if<I == 1 || I == 2> index_last( + const uint8_t* b /*binary block*/) noexcept + { + return (I == 1) ? ((b[0] & 0x3) << 4) // abbreviated 2nd symbol + : /*I == 2*/ ((b[1] & 0xF) << 2); // abbreviated 3rd symbol + } + + template <uint8_t I> + static CPPCODEC_ALWAYS_INLINE uint8_if<I != 1 && I != 2> index_last( + const uint8_t* /*binary block*/) + { + throw std::domain_error("invalid last encoding symbol index in a tail"); + } + + template <typename Result, typename ResultState> + static CPPCODEC_ALWAYS_INLINE void decode_block( + Result& decoded, ResultState&, const alphabet_index_t* idx); + + template <typename Result, typename ResultState> + static CPPCODEC_ALWAYS_INLINE void decode_tail( + Result& decoded, ResultState&, const alphabet_index_t* idx, size_t idx_len); +}; + + +template <typename CodecVariant> +template <typename Result, typename ResultState> +CPPCODEC_ALWAYS_INLINE void base64<CodecVariant>::decode_block( + Result& decoded, ResultState& state, const alphabet_index_t* idx) +{ + uint_fast32_t dec = (idx[0] << 18) | (idx[1] << 12) | (idx[2] << 6) | idx[3]; + data::put(decoded, state, static_cast<uint8_t>(dec >> 16)); + data::put(decoded, state, static_cast<uint8_t>((dec >> 8) & 0xFF)); + data::put(decoded, state, static_cast<uint8_t>(dec & 0xFF)); +} + +template <typename CodecVariant> +template <typename Result, typename ResultState> +CPPCODEC_ALWAYS_INLINE void base64<CodecVariant>::decode_tail( + Result& decoded, ResultState& state, const alphabet_index_t* idx, size_t idx_len) +{ + if (idx_len == 1) { + throw invalid_input_length( + "invalid number of symbols in last base64 block: found 1, expected 2 or 3"); + } + + // idx_len == 2: decoded size 1 + data::put(decoded, state, static_cast<uint8_t>((idx[0] << 2) + ((idx[1] & 0x30) >> 4))); + if (idx_len == 2) { + return; + } + + // idx_len == 3: decoded size 2 + data::put(decoded, state, static_cast<uint8_t>(((idx[1] & 0xF) << 4) + ((idx[2] & 0x3C) >> 2))); +} + +} // namespace detail +} // namespace cppcodec + +#endif // CPPCODEC_DETAIL_BASE64 |