/* * Base64 Encoding and Decoding * (C) 2010,2015 Jack Lloyd * * Botan is released under the Simplified BSD License (see license.txt) */ #include #include #include #include namespace Botan { namespace { static const byte BIN_TO_BASE64[64] = { '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', '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', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/' }; void do_base64_encode(char out[4], const byte in[3]) { 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) )]; } } size_t base64_encode(char out[], const byte in[], size_t input_length, size_t& input_consumed, bool final_inputs) { input_consumed = 0; size_t input_remaining = input_length; size_t output_produced = 0; while(input_remaining >= 3) { do_base64_encode(out + output_produced, in + input_consumed); input_consumed += 3; output_produced += 4; input_remaining -= 3; } if(final_inputs && input_remaining) { byte remainder[3] = { 0 }; for(size_t i = 0; i != input_remaining; ++i) remainder[i] = in[input_consumed + i]; do_base64_encode(out + output_produced, remainder); size_t empty_bits = 8 * (3 - input_remaining); size_t index = output_produced + 4 - 1; while(empty_bits >= 8) { out[index--] = '='; empty_bits -= 6; } input_consumed += input_remaining; output_produced += 4; } return output_produced; } std::string base64_encode(const byte input[], size_t input_length) { const size_t output_length = (round_up(input_length, 3) / 3) * 4; std::string output(output_length, 0); size_t consumed = 0; size_t produced = 0; if (output_length > 0) { produced = base64_encode(&output.front(), input, input_length, consumed, true); } BOTAN_ASSERT_EQUAL(consumed, input_length, "Consumed the entire input"); BOTAN_ASSERT_EQUAL(produced, output.size(), "Produced expected size"); return output; } size_t base64_decode(byte output[], const char input[], size_t input_length, size_t& input_consumed, bool final_inputs, bool ignore_ws) { /* * Base64 Decoder Lookup Table * Warning: assumes ASCII encodings */ static const byte BASE64_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, 0x3E, 0xFF, 0xFF, 0xFF, 0x3F, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B, 0x3C, 0x3D, 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, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x32, 0x33, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 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; byte decode_buf[4]; size_t decode_buf_pos = 0; size_t final_truncate = 0; clear_mem(output, input_length * 3 / 4); for(size_t i = 0; i != input_length; ++i) { const byte bin = BASE64_TO_BIN[static_cast(input[i])]; if(bin <= 0x3F) { decode_buf[decode_buf_pos] = bin; decode_buf_pos += 1; } else if(!(bin == 0x81 || (bin == 0x80 && ignore_ws))) { std::string bad_char(1, input[i]); 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("base64_decode: invalid base64 character '") + bad_char + "'"); } /* * If we're at the end of the input, pad with 0s and truncate */ if(final_inputs && (i == input_length - 1)) { if(decode_buf_pos) { for(size_t j = decode_buf_pos; j != 4; ++j) decode_buf[j] = 0; final_truncate = (4 - decode_buf_pos); decode_buf_pos = 4; } } if(decode_buf_pos == 4) { out_ptr[0] = (decode_buf[0] << 2) | (decode_buf[1] >> 4); out_ptr[1] = (decode_buf[1] << 4) | (decode_buf[2] >> 2); out_ptr[2] = (decode_buf[2] << 6) | decode_buf[3]; out_ptr += 3; decode_buf_pos = 0; input_consumed = i+1; } } while(input_consumed < input_length && BASE64_TO_BIN[static_cast(input[input_consumed])] == 0x80) { ++input_consumed; } size_t written = (out_ptr - output) - final_truncate; return written; } size_t base64_decode(byte output[], const char input[], size_t input_length, bool ignore_ws) { size_t consumed = 0; size_t written = base64_decode(output, input, input_length, consumed, true, ignore_ws); if(consumed != input_length) throw Invalid_Argument("base64_decode: input did not have full bytes"); return written; } size_t base64_decode(byte output[], const std::string& input, bool ignore_ws) { return base64_decode(output, input.data(), input.length(), ignore_ws); } secure_vector base64_decode(const char input[], size_t input_length, bool ignore_ws) { const size_t output_length = (round_up(input_length, 4) * 3) / 4; secure_vector bin(output_length); size_t written = base64_decode(bin.data(), input, input_length, ignore_ws); bin.resize(written); return bin; } secure_vector base64_decode(const std::string& input, bool ignore_ws) { return base64_decode(input.data(), input.size(), ignore_ws); } }