URLRequest fuzzer.

net/base/fuzzed_data_provider.cc

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "net/base/fuzzed_data_provider.h"
+
+#include <algorithm>
+#include <string>
+
+#include "base/logging.h"
+
+namespace net {
+
+FuzzedDataProvider::FuzzedDataProvider(const uint8_t* data, size_t size)
+    : remaining_data_(reinterpret_cast<const char*>(data), size),
+      unused_bits_(0),
+      num_unused_bits_(0) {}
+
+FuzzedDataProvider::~FuzzedDataProvider() {}
+
+size_t FuzzedDataProvider::ConsumeBytes(char* dest, size_t bytes) {
+  size_t bytes_to_write = std::min(bytes, remaining_data_.length());
+  memcpy(dest, remaining_data_.data(), bytes_to_write);
+  remaining_data_ = remaining_data_.substr(bytes_to_write);
+  return bytes_to_write;
+}
+
+uint32_t FuzzedDataProvider::ConsumeBits(size_t num_bits) {
+  CHECK_NE(0u, num_bits);
+  uint32_t out = 0;
+  while (num_bits > 0) {
+    if (num_unused_bits_ == 0) {
+      unused_bits_ = 0;
+      if (remaining_data_.length() > 0) {
+        unused_bits_ = remaining_data_.data()[remaining_data_.length() - 1];
+        remaining_data_ =
+            remaining_data_.substr(0, remaining_data_.length() - 1);
+      }
+      num_unused_bits_ = 8;
+    }
+    size_t bits_to_consume =
+        num_bits <= num_unused_bits_ ? num_bits : num_unused_bits_;
+    uint32_t new_bits = unused_bits_ & ((1 << bits_to_consume) - 1);
+    out = (out << bits_to_consume) + new_bits;
+    unused_bits_ >>= bits_to_consume;
+    num_unused_bits_ -= bits_to_consume;
+    num_bits -= bits_to_consume;
+  }
+
+  return out;
+}
+
+}  // namespace net