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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 19:33:14 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 19:33:14 +0000
commit36d22d82aa202bb199967e9512281e9a53db42c9 (patch)
tree105e8c98ddea1c1e4784a60a5a6410fa416be2de /third_party/libwebrtc/rtc_base/helpers.cc
parentInitial commit. (diff)
downloadfirefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.tar.xz
firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.zip
Adding upstream version 115.7.0esr.upstream/115.7.0esr
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'third_party/libwebrtc/rtc_base/helpers.cc')
-rw-r--r--third_party/libwebrtc/rtc_base/helpers.cc220
1 files changed, 220 insertions, 0 deletions
diff --git a/third_party/libwebrtc/rtc_base/helpers.cc b/third_party/libwebrtc/rtc_base/helpers.cc
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+/*
+ * Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ * Use of this source code is governed by a BSD-style license
+ * that can be found in the LICENSE file in the root of the source
+ * tree. An additional intellectual property rights grant can be found
+ * in the file PATENTS. All contributing project authors may
+ * be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "rtc_base/helpers.h"
+
+#include <openssl/rand.h>
+
+#include <cstdint>
+#include <limits>
+#include <memory>
+
+#include "absl/strings/string_view.h"
+#include "rtc_base/checks.h"
+#include "rtc_base/logging.h"
+
+// Protect against max macro inclusion.
+#undef max
+
+namespace rtc {
+
+// Base class for RNG implementations.
+class RandomGenerator {
+ public:
+ virtual ~RandomGenerator() {}
+ virtual bool Init(const void* seed, size_t len) = 0;
+ virtual bool Generate(void* buf, size_t len) = 0;
+};
+
+// The OpenSSL RNG.
+class SecureRandomGenerator : public RandomGenerator {
+ public:
+ SecureRandomGenerator() {}
+ ~SecureRandomGenerator() override {}
+ bool Init(const void* seed, size_t len) override { return true; }
+ bool Generate(void* buf, size_t len) override {
+ return (RAND_bytes(reinterpret_cast<unsigned char*>(buf), len) > 0);
+ }
+};
+
+// A test random generator, for predictable output.
+class TestRandomGenerator : public RandomGenerator {
+ public:
+ TestRandomGenerator() : seed_(7) {}
+ ~TestRandomGenerator() override {}
+ bool Init(const void* seed, size_t len) override { return true; }
+ bool Generate(void* buf, size_t len) override {
+ for (size_t i = 0; i < len; ++i) {
+ static_cast<uint8_t*>(buf)[i] = static_cast<uint8_t>(GetRandom());
+ }
+ return true;
+ }
+
+ private:
+ int GetRandom() {
+ return ((seed_ = seed_ * 214013L + 2531011L) >> 16) & 0x7fff;
+ }
+ int seed_;
+};
+
+namespace {
+
+// TODO: Use Base64::Base64Table instead.
+static const char kBase64[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', '+', '/'};
+
+static const char kHex[16] = {'0', '1', '2', '3', '4', '5', '6', '7',
+ '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};
+
+static const char kUuidDigit17[4] = {'8', '9', 'a', 'b'};
+
+// This round about way of creating a global RNG is to safe-guard against
+// indeterminant static initialization order.
+std::unique_ptr<RandomGenerator>& GetGlobalRng() {
+ static std::unique_ptr<RandomGenerator>& global_rng =
+ *new std::unique_ptr<RandomGenerator>(new SecureRandomGenerator());
+
+ return global_rng;
+}
+
+RandomGenerator& Rng() {
+ return *GetGlobalRng();
+}
+
+} // namespace
+
+void SetRandomTestMode(bool test) {
+ if (!test) {
+ GetGlobalRng().reset(new SecureRandomGenerator());
+ } else {
+ GetGlobalRng().reset(new TestRandomGenerator());
+ }
+}
+
+bool InitRandom(int seed) {
+ return InitRandom(reinterpret_cast<const char*>(&seed), sizeof(seed));
+}
+
+bool InitRandom(const char* seed, size_t len) {
+ if (!Rng().Init(seed, len)) {
+ RTC_LOG(LS_ERROR) << "Failed to init random generator!";
+ return false;
+ }
+ return true;
+}
+
+std::string CreateRandomString(size_t len) {
+ std::string str;
+ RTC_CHECK(CreateRandomString(len, &str));
+ return str;
+}
+
+static bool CreateRandomString(size_t len,
+ const char* table,
+ int table_size,
+ std::string* str) {
+ str->clear();
+ // Avoid biased modulo division below.
+ if (256 % table_size) {
+ RTC_LOG(LS_ERROR) << "Table size must divide 256 evenly!";
+ return false;
+ }
+ std::unique_ptr<uint8_t[]> bytes(new uint8_t[len]);
+ if (!Rng().Generate(bytes.get(), len)) {
+ RTC_LOG(LS_ERROR) << "Failed to generate random string!";
+ return false;
+ }
+ str->reserve(len);
+ for (size_t i = 0; i < len; ++i) {
+ str->push_back(table[bytes[i] % table_size]);
+ }
+ return true;
+}
+
+bool CreateRandomString(size_t len, std::string* str) {
+ return CreateRandomString(len, kBase64, 64, str);
+}
+
+bool CreateRandomString(size_t len, absl::string_view table, std::string* str) {
+ return CreateRandomString(len, table.data(), static_cast<int>(table.size()),
+ str);
+}
+
+bool CreateRandomData(size_t length, std::string* data) {
+ data->resize(length);
+ // std::string is guaranteed to use contiguous memory in c++11 so we can
+ // safely write directly to it.
+ return Rng().Generate(&data->at(0), length);
+}
+
+// Version 4 UUID is of the form:
+// xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx
+// Where 'x' is a hex digit, and 'y' is 8, 9, a or b.
+std::string CreateRandomUuid() {
+ std::string str;
+ std::unique_ptr<uint8_t[]> bytes(new uint8_t[31]);
+ RTC_CHECK(Rng().Generate(bytes.get(), 31));
+ str.reserve(36);
+ for (size_t i = 0; i < 8; ++i) {
+ str.push_back(kHex[bytes[i] % 16]);
+ }
+ str.push_back('-');
+ for (size_t i = 8; i < 12; ++i) {
+ str.push_back(kHex[bytes[i] % 16]);
+ }
+ str.push_back('-');
+ str.push_back('4');
+ for (size_t i = 12; i < 15; ++i) {
+ str.push_back(kHex[bytes[i] % 16]);
+ }
+ str.push_back('-');
+ str.push_back(kUuidDigit17[bytes[15] % 4]);
+ for (size_t i = 16; i < 19; ++i) {
+ str.push_back(kHex[bytes[i] % 16]);
+ }
+ str.push_back('-');
+ for (size_t i = 19; i < 31; ++i) {
+ str.push_back(kHex[bytes[i] % 16]);
+ }
+ return str;
+}
+
+uint32_t CreateRandomId() {
+ uint32_t id;
+ RTC_CHECK(Rng().Generate(&id, sizeof(id)));
+ return id;
+}
+
+uint64_t CreateRandomId64() {
+ return static_cast<uint64_t>(CreateRandomId()) << 32 | CreateRandomId();
+}
+
+uint32_t CreateRandomNonZeroId() {
+ uint32_t id;
+ do {
+ id = CreateRandomId();
+ } while (id == 0);
+ return id;
+}
+
+double CreateRandomDouble() {
+ return CreateRandomId() / (std::numeric_limits<uint32_t>::max() +
+ std::numeric_limits<double>::epsilon());
+}
+
+double GetNextMovingAverage(double prev_average, double cur, double ratio) {
+ return (ratio * prev_average + cur) / (ratio + 1);
+}
+
+} // namespace rtc