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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-28 09:44:33 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-28 09:44:33 +0000
commitb196c6498d22e47bb9d0da0153068ec54eac7956 (patch)
tree1a994a492581e93224a7ee6455f5d4e9d2ec8e59 /mocktracer/src/base64.cpp
parentInitial commit. (diff)
downloadopentracing-cpp-b196c6498d22e47bb9d0da0153068ec54eac7956.tar.xz
opentracing-cpp-b196c6498d22e47bb9d0da0153068ec54eac7956.zip
Adding upstream version 1.6.0.upstream/1.6.0upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r--mocktracer/src/base64.cpp174
1 files changed, 174 insertions, 0 deletions
diff --git a/mocktracer/src/base64.cpp b/mocktracer/src/base64.cpp
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+++ b/mocktracer/src/base64.cpp
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+/*
+ * Envoy
+ * Copyright 2016-2017 Lyft Inc.
+ *
+ * Licensed under Apache License 2.0. See LICENSE.apache for terms.
+ */
+
+#include "base64.h"
+
+#include <cstdint>
+#include <string>
+
+namespace opentracing {
+BEGIN_OPENTRACING_ABI_NAMESPACE
+namespace mocktracer {
+static constexpr char CHAR_TABLE[] =
+ "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+
+// Conversion table is taken from
+// https://opensource.apple.com/source/QuickTimeStreamingServer/QuickTimeStreamingServer-452/CommonUtilitiesLib/base64.c
+static const unsigned char REVERSE_LOOKUP_TABLE[256] = {
+ 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
+ 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
+ 64, 64, 64, 64, 64, 62, 64, 64, 64, 63, 52, 53, 54, 55, 56, 57, 58, 59, 60,
+ 61, 64, 64, 64, 64, 64, 64, 64, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,
+ 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 64, 64, 64, 64,
+ 64, 64, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42,
+ 43, 44, 45, 46, 47, 48, 49, 50, 51, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
+ 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
+ 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
+ 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
+ 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
+ 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
+ 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
+ 64, 64, 64, 64, 64, 64, 64, 64, 64};
+
+std::string Base64::decode(const char* input, size_t length) {
+ if (length % 4 || length == 0) {
+ return {};
+ }
+
+ // First position of "valid" padding character.
+ uint64_t first_padding_index = length;
+ int max_length = static_cast<int>(length) / 4 * 3;
+ // At most last two chars can be '='.
+ if (input[length - 1] == '=') {
+ max_length--;
+ first_padding_index = length - 1;
+ if (input[length - 2] == '=') {
+ max_length--;
+ first_padding_index = length - 2;
+ }
+ }
+ std::string result;
+ result.reserve(static_cast<size_t>(max_length));
+
+ uint64_t bytes_left = length;
+ uint64_t cur_read = 0;
+
+ // Read input string by group of 4 chars, length of input string must be
+ // divided evenly by 4. Decode 4 chars 6 bits each into 3 chars 8 bits each.
+ while (bytes_left > 0) {
+ // Take first 6 bits from 1st converted char and first 2 bits from 2nd
+ // converted char, make 8 bits char from it. Use conversion table to map
+ // char to decoded value (value is between 0 and 63 inclusive for a valid
+ // character).
+ const unsigned char a =
+ REVERSE_LOOKUP_TABLE[static_cast<uint32_t>(input[cur_read])];
+ const unsigned char b =
+ REVERSE_LOOKUP_TABLE[static_cast<uint32_t>(input[cur_read + 1])];
+ if (a == 64 || b == 64) {
+ // Input contains an invalid character.
+ return {};
+ }
+ result.push_back(static_cast<char>(a << 2 | b >> 4));
+ const unsigned char c =
+ REVERSE_LOOKUP_TABLE[static_cast<uint32_t>(input[cur_read + 2])];
+
+ // Decoded value 64 means invalid character unless we already know it is a
+ // valid padding. If so, following characters are all padding. Also we
+ // should check there are no unused bits.
+ if (c == 64) {
+ if (first_padding_index != cur_read + 2) {
+ // Input contains an invalid character.
+ return {};
+ } else if (b & 15) {
+ // There are unused bits at tail.
+ return {};
+ } else {
+ return result;
+ }
+ }
+ // Take last 4 bits from 2nd converted char and 4 first bits from 3rd
+ // converted char.
+ result.push_back(static_cast<char>(b << 4 | c >> 2));
+
+ const unsigned char d =
+ REVERSE_LOOKUP_TABLE[static_cast<uint32_t>(input[cur_read + 3])];
+ if (d == 64) {
+ if (first_padding_index != cur_read + 3) {
+ // Input contains an invalid character.
+ return {};
+ } else if (c & 3) {
+ // There are unused bits at tail.
+ return {};
+ } else {
+ return result;
+ }
+ }
+ // Take last 2 bits from 3rd converted char and all(6) bits from 4th
+ // converted char.
+ result.push_back(static_cast<char>(c << 6 | d));
+
+ cur_read += 4;
+ bytes_left -= 4;
+ }
+
+ return result;
+}
+
+void Base64::encodeBase(const uint8_t cur_char, uint64_t pos, uint8_t& next_c,
+ std::string& ret) {
+ switch (pos % 3) {
+ case 0:
+ ret.push_back(CHAR_TABLE[cur_char >> 2]);
+ next_c = static_cast<uint8_t>((cur_char & 0x03) << 4);
+ break;
+ case 1:
+ ret.push_back(CHAR_TABLE[next_c | (cur_char >> 4)]);
+ next_c = static_cast<uint8_t>((cur_char & 0x0f) << 2);
+ break;
+ case 2:
+ ret.push_back(CHAR_TABLE[next_c | (cur_char >> 6)]);
+ ret.push_back(CHAR_TABLE[cur_char & 0x3f]);
+ next_c = 0;
+ break;
+ }
+}
+
+void Base64::encodeLast(uint64_t pos, uint8_t last_char, std::string& ret) {
+ switch (pos % 3) {
+ case 1:
+ ret.push_back(CHAR_TABLE[last_char]);
+ ret.push_back('=');
+ ret.push_back('=');
+ break;
+ case 2:
+ ret.push_back(CHAR_TABLE[last_char]);
+ ret.push_back('=');
+ break;
+ default:
+ break;
+ }
+}
+
+std::string Base64::encode(const char* input, uint64_t length) {
+ uint64_t output_length = (length + 2) / 3 * 4;
+ std::string ret;
+ ret.reserve(output_length);
+
+ uint64_t pos = 0;
+ uint8_t next_c = 0;
+
+ for (uint64_t i = 0; i < length; ++i) {
+ encodeBase(static_cast<uint8_t>(input[i]), pos++, next_c, ret);
+ }
+
+ encodeLast(pos, next_c, ret);
+
+ return ret;
+}
+} // namespace mocktracer
+END_OPENTRACING_ABI_NAMESPACE
+} // namespace opentracing