/* * Base32 Encoding and Decoding * (C) 2018 Erwan Chaussy * (C) 2018 Jack Lloyd * * Botan is released under the Simplified BSD License (see license.txt) */ #include #include #include namespace Botan { namespace { class Base32 final { public: static inline std::string name() noexcept { return "base32"; } static inline size_t encoding_bytes_in() noexcept { return m_encoding_bytes_in; } static inline size_t encoding_bytes_out() noexcept { return m_encoding_bytes_out; } static inline size_t decoding_bytes_in() noexcept { return m_encoding_bytes_out; } static inline size_t decoding_bytes_out() noexcept { return m_encoding_bytes_in; } static inline size_t bits_consumed() noexcept { return m_encoding_bits; } static inline size_t remaining_bits_before_padding() noexcept { return m_remaining_bits_before_padding; } static inline size_t encode_max_output(size_t input_length) { return (round_up(input_length, m_encoding_bytes_in) / m_encoding_bytes_in) * m_encoding_bytes_out; } static inline size_t decode_max_output(size_t input_length) { return (round_up(input_length, m_encoding_bytes_out) * m_encoding_bytes_in) / m_encoding_bytes_out; } static void encode(char out[8], const uint8_t in[5]) noexcept { out[0] = Base32::m_bin_to_base32[(in[0] & 0xF8) >> 3]; out[1] = Base32::m_bin_to_base32[((in[0] & 0x07) << 2) | (in[1] >> 6)]; out[2] = Base32::m_bin_to_base32[((in[1] & 0x3E) >> 1)]; out[3] = Base32::m_bin_to_base32[((in[1] & 0x01) << 4) | (in[2] >> 4)]; out[4] = Base32::m_bin_to_base32[((in[2] & 0x0F) << 1) | (in[3] >> 7)]; out[5] = Base32::m_bin_to_base32[((in[3] & 0x7C) >> 2)]; out[6] = Base32::m_bin_to_base32[((in[3] & 0x03) << 3) | (in[4] >> 5)]; out[7] = Base32::m_bin_to_base32[in[4] & 0x1F]; } static inline uint8_t lookup_binary_value(char input) noexcept { return Base32::m_base32_to_bin[static_cast(input)]; } static inline bool check_bad_char(uint8_t bin, char input, bool ignore_ws) { if(bin <= 0x1F) { return true; } else if(!(bin == 0x81 || (bin == 0x80 && ignore_ws))) { std::string bad_char(1, input); if(bad_char == "\t") { bad_char = "\\t"; } else if(bad_char == "\n") { bad_char = "\\n"; } else if(bad_char == "\r") { bad_char = "\\r"; } throw Invalid_Argument( std::string("base32_decode: invalid base32 character '") + bad_char + "'"); } return false; } static void decode(uint8_t* out_ptr, const uint8_t decode_buf[8]) { out_ptr[0] = (decode_buf[0] << 3) | (decode_buf[1] >> 2); out_ptr[1] = (decode_buf[1] << 6) | (decode_buf[2] << 1) | (decode_buf[3] >> 4); out_ptr[2] = (decode_buf[3] << 4) | (decode_buf[4] >> 1); out_ptr[3] = (decode_buf[4] << 7) | (decode_buf[5] << 2) | (decode_buf[6] >> 3); out_ptr[4] = (decode_buf[6] << 5) | decode_buf[7]; } static inline size_t bytes_to_remove(size_t final_truncate) { return final_truncate ? (final_truncate / 2) + 1 : 0; } private: static const size_t m_encoding_bits = 5; static const size_t m_remaining_bits_before_padding = 6; static const size_t m_encoding_bytes_in = 5; static const size_t m_encoding_bytes_out = 8; static const uint8_t m_bin_to_base32[32]; static const uint8_t m_base32_to_bin[256]; }; const uint8_t Base32::m_bin_to_base32[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' }; /* * base32 Decoder Lookup Table * Warning: assumes ASCII encodings */ const uint8_t Base32::m_base32_to_bin[256] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x80, 0x80, 0xFF, 0xFF, 0x80, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x80, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x81, 0xFF, 0xFF, 0xFF, 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, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF }; } size_t base32_encode(char out[], const uint8_t in[], size_t input_length, size_t& input_consumed, bool final_inputs) { return base_encode(Base32(), out, in, input_length, input_consumed, final_inputs); } std::string base32_encode(const uint8_t input[], size_t input_length) { return base_encode_to_string(Base32(), input, input_length); } size_t base32_decode(uint8_t out[], const char in[], size_t input_length, size_t& input_consumed, bool final_inputs, bool ignore_ws) { return base_decode(Base32(), out, in, input_length, input_consumed, final_inputs, ignore_ws); } size_t base32_decode(uint8_t output[], const char input[], size_t input_length, bool ignore_ws) { return base_decode_full(Base32(), output, input, input_length, ignore_ws); } size_t base32_decode(uint8_t output[], const std::string& input, bool ignore_ws) { return base32_decode(output, input.data(), input.length(), ignore_ws); } secure_vector base32_decode(const char input[], size_t input_length, bool ignore_ws) { return base_decode_to_vec>(Base32(), input, input_length, ignore_ws); } secure_vector base32_decode(const std::string& input, bool ignore_ws) { return base32_decode(input.data(), input.size(), ignore_ws); } }