diff options
Diffstat (limited to 'lib/codec/hex/hex.cpp')
| -rw-r--r-- | lib/codec/hex/hex.cpp | 204 |
1 files changed, 204 insertions, 0 deletions
diff --git a/lib/codec/hex/hex.cpp b/lib/codec/hex/hex.cpp new file mode 100644 index 000000000..104125894 --- /dev/null +++ b/lib/codec/hex/hex.cpp @@ -0,0 +1,204 @@ +/* +* Hex Encoding and Decoding +* (C) 2010 Jack Lloyd +* +* Distributed under the terms of the Botan license +*/ + +#include <botan/hex.h> +#include <botan/mem_ops.h> +#include <stdexcept> + +namespace Botan { + +void hex_encode(char output[], + const byte input[], + size_t input_length, + bool uppercase) + { + static const byte BIN_TO_HEX_UPPER[16] = { + '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', + 'A', 'B', 'C', 'D', 'E', 'F' }; + + static const byte BIN_TO_HEX_LOWER[16] = { + '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', + 'a', 'b', 'c', 'd', 'e', 'f' }; + + const byte* tbl = uppercase ? BIN_TO_HEX_UPPER : BIN_TO_HEX_LOWER; + + for(size_t i = 0; i != input_length; ++i) + { + byte x = input[i]; + output[2*i ] = tbl[(x >> 4) & 0x0F]; + output[2*i+1] = tbl[(x ) & 0x0F]; + } + } + +std::string hex_encode(const byte input[], + size_t input_length, + bool uppercase) + { + std::string output(2 * input_length, 0); + + if(input_length) + hex_encode(&output[0], input, input_length, uppercase); + + return output; + } + +size_t hex_decode(byte output[], + const char input[], + size_t input_length, + size_t& input_consumed, + bool ignore_ws) + { + /* + * Mapping of hex characters to either their binary equivalent + * or to an error code. + * If valid hex (0-9 A-F a-f), the value. + * If whitespace, then 0x80 + * Otherwise 0xFF + * Warning: this table assumes ASCII character encodings + */ + + static const byte HEX_TO_BIN[256] = { + 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x80, + 0x80, 0xFF, 0xFF, 0xFF, 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, 0x00, 0x01, + 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0xFF, 0xFF, + 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, + 0x0F, 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, 0x0A, 0x0B, 0x0C, + 0x0D, 0x0E, 0x0F, 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 }; + + byte* out_ptr = output; + bool top_nibble = true; + + clear_mem(output, input_length / 2); + + for(size_t i = 0; i != input_length; ++i) + { + const byte bin = HEX_TO_BIN[static_cast<byte>(input[i])]; + + if(bin >= 0x10) + { + if(bin == 0x80 && ignore_ws) + continue; + + std::string bad_char(1, input[i]); + if(bad_char == "\t") + bad_char = "\\t"; + else if(bad_char == "\n") + bad_char = "\\n"; + + throw std::invalid_argument( + std::string("hex_decode: invalid hex character '") + + bad_char + "'"); + } + + *out_ptr |= bin << (top_nibble*4); + + top_nibble = !top_nibble; + if(top_nibble) + ++out_ptr; + } + + input_consumed = input_length; + size_t written = (out_ptr - output); + + /* + * We only got half of a byte at the end; zap the half-written + * output and mark it as unread + */ + if(!top_nibble) + { + *out_ptr = 0; + input_consumed -= 1; + } + + return written; + } + +size_t hex_decode(byte output[], + const char input[], + size_t input_length, + bool ignore_ws) + { + size_t consumed = 0; + size_t written = hex_decode(output, input, input_length, + consumed, ignore_ws); + + if(consumed != input_length) + throw std::invalid_argument("hex_decode: input did not have full bytes"); + + return written; + } + +size_t hex_decode(byte output[], + const std::string& input, + bool ignore_ws) + { + return hex_decode(output, &input[0], input.length(), ignore_ws); + } + +secure_vector<byte> hex_decode_locked(const char input[], + size_t input_length, + bool ignore_ws) + { + secure_vector<byte> bin(1 + input_length / 2); + + size_t written = hex_decode(&bin[0], + input, + input_length, + ignore_ws); + + bin.resize(written); + return bin; + } + +secure_vector<byte> hex_decode_locked(const std::string& input, + bool ignore_ws) + { + return hex_decode_locked(&input[0], input.size(), ignore_ws); + } + +std::vector<byte> hex_decode(const char input[], + size_t input_length, + bool ignore_ws) + { + std::vector<byte> bin(1 + input_length / 2); + + size_t written = hex_decode(&bin[0], + input, + input_length, + ignore_ws); + + bin.resize(written); + return bin; + } + +std::vector<byte> hex_decode(const std::string& input, + bool ignore_ws) + { + return hex_decode(&input[0], input.size(), ignore_ws); + } + +} |