Add a buffer reader/writer for NTLM.

net/ntlm/ntlm_buffer_writer.cc

Index: net/ntlm/ntlm_buffer_writer.cc
diff --git a/net/ntlm/ntlm_buffer_writer.cc b/net/ntlm/ntlm_buffer_writer.cc
new file mode 100644
index 0000000000000000000000000000000000000000..0b5e3aa5c8141acb65fe3107beb08496e42def57
--- /dev/null
+++ b/net/ntlm/ntlm_buffer_writer.cc
@@ -0,0 +1,152 @@
+// Copyright 2017 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/ntlm/ntlm_buffer_writer.h"
+
+#include <string.h>
+
+#include "base/logging.h"
+#include "base/strings/utf_string_conversions.h"
+#include "build/build_config.h"
+
+namespace net {
+namespace ntlm {
+
+NtlmBufferWriter::NtlmBufferWriter(size_t buffer_len)
+    : buffer_len_(buffer_len), cursor_(0) {
+  buffer_.reset(new uint8_t[buffer_len]());
+}
+
+NtlmBufferWriter::~NtlmBufferWriter() {}
+
+bool NtlmBufferWriter::CanWrite(size_t len) const {
+  if (!GetBufferPtr())
+    return false;
+
+  DCHECK_LE(GetCursor(), GetLength());
+
+  if (len == 0)
+    return true;
+
+  return (len <= GetLength()) && (GetCursor() <= GetLength() - len);
+}
+
+bool NtlmBufferWriter::WriteUInt16(uint16_t value) {
+  return WriteUInt<uint16_t>(value);
+}
+
+bool NtlmBufferWriter::WriteUInt32(uint32_t value) {
+  return WriteUInt<uint32_t>(value);
+}
+
+bool NtlmBufferWriter::WriteUInt64(uint64_t value) {
+  return WriteUInt<uint64_t>(value);
+}
+
+bool NtlmBufferWriter::WriteFlags(NegotiateFlags flags) {
+  return WriteUInt32(static_cast<uint32_t>(flags));
+}
+
+bool NtlmBufferWriter::WriteBytes(const uint8_t* buffer, size_t len) {
+  if (!CanWrite(len))
+    return false;
+
+  memcpy(reinterpret_cast<void*>(GetBufferPtrAtCursor()),
+         reinterpret_cast<const void*>(buffer), len);
+
+  AdvanceCursor(len);
+  return true;
+}
+
+bool NtlmBufferWriter::WriteBytes(base::StringPiece bytes) {
+  return WriteBytes(reinterpret_cast<const uint8_t*>(bytes.data()),
+                    bytes.length());
+}
+
+bool NtlmBufferWriter::WriteZeros(size_t count) {
+  if (!CanWrite(count))
+    return false;
+
+  memset(GetBufferPtrAtCursor(), 0, count);
+  AdvanceCursor(count);
+  return true;
+}
+
+bool NtlmBufferWriter::WriteSecurityBuffer(SecurityBuffer sec_buf) {
+  return WriteUInt16(sec_buf.length) && WriteUInt16(sec_buf.length) &&
+         WriteUInt32(sec_buf.offset);
+}
+
+bool NtlmBufferWriter::WriteUtf8String(const std::string& str) {
+  return WriteBytes(reinterpret_cast<const uint8_t*>(str.c_str()),
+                    str.length());
+}
+
+bool NtlmBufferWriter::WriteUtf16AsUtf8String(const base::string16& str) {
+  std::string utf8 = base::UTF16ToUTF8(str);
+  return WriteUtf8String(utf8);
+}
+
+bool NtlmBufferWriter::WriteUtf8AsUtf16String(const std::string& str) {
+  base::string16 unicode = base::UTF8ToUTF16(str);
+  return WriteUtf16String(unicode);
+}
+
+bool NtlmBufferWriter::WriteUtf16String(const base::string16& str) {
+  size_t num_bytes = str.length() * 2;
+  if (!CanWrite(num_bytes))
+    return false;
+
+#if defined(ARCH_CPU_BIG_ENDIAN)
+  uint8_t* ptr = reinterpret_cast<uint8_t*>(GetBufferPtrAtCursor());
+
+  for (int i = 0; i < num_bytes; i += 2) {
+    ptr[i] = str[i / 2] & 0xff;
+    ptr[i + 1] = str[i / 2] >> 8;
+  }
+#else
+  memcpy(reinterpret_cast<void*>(GetBufferPtrAtCursor()), str.c_str(),
+         num_bytes);
+
+#endif
+
+  AdvanceCursor(num_bytes);
+  return true;
+}
+
+bool NtlmBufferWriter::WriteSignature() {
+  return WriteBytes(kSignature, kSignatureLen);
+}
+
+bool NtlmBufferWriter::WriteMessageType(MessageType message_type) {
+  return WriteUInt32(static_cast<uint32_t>(message_type));
+}
+
+bool NtlmBufferWriter::WriteMessageHeader(MessageType message_type) {
+  return WriteSignature() && WriteMessageType(message_type);
+}
+
+template <typename T>
+bool NtlmBufferWriter::WriteUInt(T value) {
+  size_t int_size = sizeof(T);
+  if (!CanWrite(int_size))
+    return false;
+
+  for (size_t i = 0; i < int_size; i++) {
+    GetBufferPtrAtCursor()[i] = static_cast<uint8_t>(value & 0xff);
+    value >>= 8;
+  }
+
+  AdvanceCursor(int_size);
+  return true;
+}
+
+void NtlmBufferWriter::SetCursor(size_t cursor) {
+  DCHECK(GetBufferPtr() && cursor <= GetLength());
+
+  cursor_ = cursor;
+}
+
+}  // namespace ntlm
+}  // namespace net