diff options
Diffstat (limited to 'src/codec/base64/base64.cpp')
| -rw-r--r-- | src/codec/base64/base64.cpp | 225 |
1 files changed, 225 insertions, 0 deletions
diff --git a/src/codec/base64/base64.cpp b/src/codec/base64/base64.cpp new file mode 100644 index 000000000..0e01d94f3 --- /dev/null +++ b/src/codec/base64/base64.cpp @@ -0,0 +1,225 @@ +/************************************************* +* Base64 Encoder/Decoder Source File * +* (C) 1999-2007 Jack Lloyd * +*************************************************/ + +#include <botan/base64.h> +#include <botan/charset.h> +#include <algorithm> + +namespace Botan { + +/************************************************* +* Base64_Encoder Constructor * +*************************************************/ +Base64_Encoder::Base64_Encoder(bool breaks, u32bit length, bool t_n) : + line_length(breaks ? length : 0), trailing_newline(t_n) + { + in.create(48); + out.create(4); + + counter = position = 0; + } + +/************************************************* +* Base64 Encoding Operation * +*************************************************/ +void Base64_Encoder::encode(const byte in[3], byte out[4]) + { + out[0] = BIN_TO_BASE64[((in[0] & 0xFC) >> 2)]; + out[1] = BIN_TO_BASE64[((in[0] & 0x03) << 4) | (in[1] >> 4)]; + out[2] = BIN_TO_BASE64[((in[1] & 0x0F) << 2) | (in[2] >> 6)]; + out[3] = BIN_TO_BASE64[((in[2] & 0x3F) )]; + } + +/************************************************* +* Encode and send a block * +*************************************************/ +void Base64_Encoder::encode_and_send(const byte block[], u32bit length) + { + for(u32bit j = 0; j != length; j += 3) + { + encode(block + j, out); + do_output(out, 4); + } + } + +/************************************************* +* Handle the output * +*************************************************/ +void Base64_Encoder::do_output(const byte input[], u32bit length) + { + if(line_length == 0) + send(input, length); + else + { + u32bit remaining = length, offset = 0; + while(remaining) + { + u32bit sent = std::min(line_length - counter, remaining); + send(input + offset, sent); + counter += sent; + remaining -= sent; + offset += sent; + if(counter == line_length) + { + send('\n'); + counter = 0; + } + } + } + } + +/************************************************* +* Convert some data into Base64 * +*************************************************/ +void Base64_Encoder::write(const byte input[], u32bit length) + { + in.copy(position, input, length); + if(position + length >= in.size()) + { + encode_and_send(in, in.size()); + input += (in.size() - position); + length -= (in.size() - position); + while(length >= in.size()) + { + encode_and_send(input, in.size()); + input += in.size(); + length -= in.size(); + } + in.copy(input, length); + position = 0; + } + position += length; + } + +/************************************************* +* Flush buffers * +*************************************************/ +void Base64_Encoder::end_msg() + { + u32bit start_of_last_block = 3 * (position / 3), + left_over = position % 3; + encode_and_send(in, start_of_last_block); + + if(left_over) + { + SecureBuffer<byte, 3> remainder(in + start_of_last_block, left_over); + + encode(remainder, out); + + u32bit empty_bits = 8 * (3 - left_over), index = 4 - 1; + while(empty_bits >= 8) + { + out[index--] = '='; + empty_bits -= 6; + } + + do_output(out, 4); + } + + if(trailing_newline || (counter && line_length)) + send('\n'); + + counter = position = 0; + } + +/************************************************* +* Base64_Decoder Constructor * +*************************************************/ +Base64_Decoder::Base64_Decoder(Decoder_Checking c) : checking(c) + { + in.create(48); + out.create(3); + position = 0; + } + +/************************************************* +* Check if a character is a valid Base64 char * +*************************************************/ +bool Base64_Decoder::is_valid(byte in) + { + return (BASE64_TO_BIN[in] != 0x80); + } + +/************************************************* +* Base64 Decoding Operation * +*************************************************/ +void Base64_Decoder::decode(const byte in[4], byte out[3]) + { + out[0] = ((BASE64_TO_BIN[in[0]] << 2) | (BASE64_TO_BIN[in[1]] >> 4)); + out[1] = ((BASE64_TO_BIN[in[1]] << 4) | (BASE64_TO_BIN[in[2]] >> 2)); + out[2] = ((BASE64_TO_BIN[in[2]] << 6) | (BASE64_TO_BIN[in[3]])); + } + +/************************************************* +* Decode and send a block * +*************************************************/ +void Base64_Decoder::decode_and_send(const byte block[], u32bit length) + { + for(u32bit j = 0; j != length; j += 4) + { + decode(block + j, out); + send(out, 3); + } + } + +/************************************************* +* Handle processing an invalid character * +*************************************************/ +void Base64_Decoder::handle_bad_char(byte c) + { + if(c == '=' || checking == NONE) + return; + + if((checking == IGNORE_WS) && Charset::is_space(c)) + return; + + throw Decoding_Error( + std::string("Base64_Decoder: Invalid base64 character '") + + static_cast<char>(c) + "'" + ); + } + +/************************************************* +* Convert some data from Base64 * +*************************************************/ +void Base64_Decoder::write(const byte input[], u32bit length) + { + for(u32bit j = 0; j != length; ++j) + { + if(is_valid(input[j])) + in[position++] = input[j]; + else + handle_bad_char(input[j]); + + if(position == in.size()) + { + decode_and_send(in, in.size()); + position = 0; + } + } + } + +/************************************************* +* Flush buffers * +*************************************************/ +void Base64_Decoder::end_msg() + { + if(position != 0) + { + u32bit start_of_last_block = 4 * (position / 4), + left_over = position % 4; + decode_and_send(in, start_of_last_block); + + if(left_over) + { + SecureBuffer<byte, 4> remainder(in + start_of_last_block, left_over); + decode(remainder, out); + send(out, ((left_over == 1) ? (1) : (left_over - 1))); + } + } + position = 0; + } + +} |