From a01d11ac19a77fa326659692adeb65c566435b43 Mon Sep 17 00:00:00 2001 From: Conrad Pankoff Date: Sun, 13 Dec 2020 09:35:14 +1100 Subject: [PATCH] AK: Add {encode,decode}_hex similar to {encode,decode}_base64 --- AK/Hex.cpp | 81 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ AK/Hex.h | 44 +++++++++++++++++++++++++++++ 2 files changed, 125 insertions(+) create mode 100644 AK/Hex.cpp create mode 100644 AK/Hex.h diff --git a/AK/Hex.cpp b/AK/Hex.cpp new file mode 100644 index 00000000000..a5b20057a3b --- /dev/null +++ b/AK/Hex.cpp @@ -0,0 +1,81 @@ +/* + * Copyright (c) 2020, Andreas Kling + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, this + * list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE + * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR + * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER + * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +namespace AK { + +static u8 decode_hex_digit(char digit) +{ + if (digit >= '0' && digit <= '9') + return digit - '0'; + if (digit >= 'a' && digit <= 'f') + return 10 + (digit - 'a'); + if (digit >= 'A' && digit <= 'F') + return 10 + (digit - 'A'); + return 255; +} + +Optional decode_hex(const StringView& input) +{ + if ((input.length() % 2) != 0) + return {}; + + auto output = ByteBuffer::create_zeroed(input.length() / 2); + + for (long unsigned int i = 0; i < input.length() / 2; i++) { + auto c1 = decode_hex_digit(input[i * 2]); + if (c1 >= 16) + return {}; + + auto c2 = decode_hex_digit(input[i * 2 + 1]); + if (c2 >= 16) + return {}; + + output[i] = (c1 << 4) + c2; + } + + return output; +} + +String encode_hex(ReadonlyBytes input) +{ + StringBuilder output(input.size() * 2); + + for (auto ch : input) + output.appendf("%02x", ch); + + return output.build(); +} + +} diff --git a/AK/Hex.h b/AK/Hex.h new file mode 100644 index 00000000000..d3833d81117 --- /dev/null +++ b/AK/Hex.h @@ -0,0 +1,44 @@ +/* + * Copyright (c) 2020, Andreas Kling + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, this + * list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE + * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR + * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER + * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#pragma once + +#include +#include +#include +#include +#include + +namespace AK { + +Optional decode_hex(const StringView&); + +String encode_hex(ReadonlyBytes); + +} + +using AK::decode_hex; +using AK::encode_hex;