Implement the NTLM authentication scheme by porting...

net/http/http_auth_handler_ntlm.cc

+// Copyright (c) 2009 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/http/http_auth_handler_ntlm.h"
+
+#include <stdlib.h>
+// For gethostname
+#if defined(OS_POSIX)
+#include <unistd.h>
+#elif defined(OS_WIN)
+#include <winsock2.h>
+#endif
+
+#include "base/md5.h"
+#include "base/rand_util.h"
+#include "base/string_util.h"
+#include "base/sys_string_conversions.h"
+#include "net/base/base64.h"
+#include "net/base/net_errors.h"
+#include "net/http/des.h"
+#include "net/http/md4.h"
+
+namespace net {
+
+// Based on mozilla/security/manager/ssl/src/nsNTLMAuthModule.cpp,
+// CVS rev. 1.14.
+//
+// TODO(wtc):
+// - The IS_BIG_ENDIAN code is not tested.
+// - Enable the logging code or just delete it.
+// - Delete or comment out the LM code, which hasn't been tested and isn't
+//   being used.
+
+/* ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is Mozilla.
+ *
+ * The Initial Developer of the Original Code is IBM Corporation.
+ * Portions created by IBM Corporation are Copyright (C) 2003
+ * IBM Corporation. All Rights Reserved.
+ *
+ * Contributor(s):
+ *   Darin Fisher <darin@meer.net>
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+// Discover the endianness by testing processor architecture.
+#if defined(ARCH_CPU_X86) || defined(ARCH_CPU_X86_64)
+#define IS_LITTLE_ENDIAN 1
+#undef  IS_BIG_ENDIAN
+#else
+#error "Unknown endianness"
+#endif
+
+#define NTLM_LOG(x) ((void) 0)
+
+//-----------------------------------------------------------------------------
+// This file contains a cross-platform NTLM authentication implementation. It
+// is based on documentation from: http://davenport.sourceforge.net/ntlm.html
+//-----------------------------------------------------------------------------
+
+enum {
+  NTLM_NegotiateUnicode             = 0x00000001,
+  NTLM_NegotiateOEM                 = 0x00000002,
+  NTLM_RequestTarget                = 0x00000004,
+  NTLM_Unknown1                     = 0x00000008,
+  NTLM_NegotiateSign                = 0x00000010,
+  NTLM_NegotiateSeal                = 0x00000020,
+  NTLM_NegotiateDatagramStyle       = 0x00000040,
+  NTLM_NegotiateLanManagerKey       = 0x00000080,
+  NTLM_NegotiateNetware             = 0x00000100,
+  NTLM_NegotiateNTLMKey             = 0x00000200,
+  NTLM_Unknown2                     = 0x00000400,
+  NTLM_Unknown3                     = 0x00000800,
+  NTLM_NegotiateDomainSupplied      = 0x00001000,
+  NTLM_NegotiateWorkstationSupplied = 0x00002000,
+  NTLM_NegotiateLocalCall           = 0x00004000,
+  NTLM_NegotiateAlwaysSign          = 0x00008000,
+  NTLM_TargetTypeDomain             = 0x00010000,
+  NTLM_TargetTypeServer             = 0x00020000,
+  NTLM_TargetTypeShare              = 0x00040000,
+  NTLM_NegotiateNTLM2Key            = 0x00080000,
+  NTLM_RequestInitResponse          = 0x00100000,
+  NTLM_RequestAcceptResponse        = 0x00200000,
+  NTLM_RequestNonNTSessionKey       = 0x00400000,
+  NTLM_NegotiateTargetInfo          = 0x00800000,
+  NTLM_Unknown4                     = 0x01000000,
+  NTLM_Unknown5                     = 0x02000000,
+  NTLM_Unknown6                     = 0x04000000,
+  NTLM_Unknown7                     = 0x08000000,
+  NTLM_Unknown8                     = 0x10000000,
+  NTLM_Negotiate128                 = 0x20000000,
+  NTLM_NegotiateKeyExchange         = 0x40000000,
+  NTLM_Negotiate56                  = 0x80000000
+};
+
+// We send these flags with our type 1 message.
+enum {
+  NTLM_TYPE1_FLAGS =
+      NTLM_NegotiateUnicode |
+      NTLM_NegotiateOEM |
+      NTLM_RequestTarget |
+      NTLM_NegotiateNTLMKey |
+      NTLM_NegotiateAlwaysSign |
+      NTLM_NegotiateNTLM2Key
+};
+
+static const char NTLM_SIGNATURE[] = "NTLMSSP";
+static const char NTLM_TYPE1_MARKER[] = { 0x01, 0x00, 0x00, 0x00 };
+static const char NTLM_TYPE2_MARKER[] = { 0x02, 0x00, 0x00, 0x00 };
+static const char NTLM_TYPE3_MARKER[] = { 0x03, 0x00, 0x00, 0x00 };
+
+enum {
+  NTLM_TYPE1_HEADER_LEN = 32,
+  NTLM_TYPE2_HEADER_LEN = 32,
+  NTLM_TYPE3_HEADER_LEN = 64,
+
+  LM_HASH_LEN = 16,
+  LM_RESP_LEN = 24,
+
+  NTLM_HASH_LEN = 16,
+  NTLM_RESP_LEN = 24
+};
+
+//-----------------------------------------------------------------------------
+
+// The return value of this function controls whether or not the LM hash will
+// be included in response to a NTLM challenge.
+//
+// In Mozilla, this function returns the value of the boolean preference
+// "network.ntlm.send-lm-response".  By default, the preference is disabled
+// since servers should almost never need the LM hash, and the LM hash is what
+// makes NTLM authentication less secure.  See
+// https://bugzilla.mozilla.org/show_bug.cgi?id=250691 for further details.
+//
+// We just return a hardcoded false.
+static bool SendLM() {
+  return false;
+}
+
+//-----------------------------------------------------------------------------
+
+#define LogFlags(x) ((void) 0)
+#define LogBuf(a, b, c) ((void) 0)
+#define LogToken(a, b, c) ((void) 0)
+
+//-----------------------------------------------------------------------------
+
+// Byte order swapping.
+#define SWAP16(x) ((((x) & 0xff) << 8) | (((x) >> 8) & 0xff))
+#define SWAP32(x) ((SWAP16((x) & 0xffff) << 16) | (SWAP16((x) >> 16)))
+
+static void* WriteBytes(void* buf, const void* data, uint32 data_len) {
+  memcpy(buf, data, data_len);
+  return static_cast<char*>(buf) + data_len;
+}
+
+static void* WriteDWORD(void* buf, uint32 dword) {
+#ifdef IS_BIG_ENDIAN
+  // NTLM uses little endian on the wire.
+  dword = SWAP32(dword);
+#endif
+  return WriteBytes(buf, &dword, sizeof(dword));
+}
+
+static void* WriteSecBuf(void* buf, uint16 length, uint32 offset) {
+#ifdef IS_BIG_ENDIAN
+  length = SWAP16(length);
+  offset = SWAP32(offset);
+#endif
+  buf = WriteBytes(buf, &length, sizeof(length));
+  buf = WriteBytes(buf, &length, sizeof(length));
+  buf = WriteBytes(buf, &offset, sizeof(offset));
+  return buf;
+}
+
+#ifdef IS_BIG_ENDIAN
+/**
+ * WriteUnicodeLE copies a unicode string from one buffer to another.  The
+ * resulting unicode string is in little-endian format.  The input string is
+ * assumed to be in the native endianness of the local machine.  It is safe
+ * to pass the same buffer as both input and output, which is a handy way to
+ * convert the unicode buffer to little-endian on big-endian platforms.
+ */
+static void* WriteUnicodeLE(void* buf, const char16* str, uint32 str_len) {
+  // Convert input string from BE to LE.
+  uint8* cursor = static_cast<uint8*>(buf);
+  const uint8* input  = reinterpret_cast<const uint8*>(str);
+  for (uint32 i = 0; i < str_len; ++i, input += 2, cursor += 2) {
+    // Allow for the case where |buf == str|.
+    uint8 temp = input[0];
+    cursor[0] = input[1];
+    cursor[1] = temp;
+  }
+  return buf;
+}
+#endif
+
+static uint16 ReadUint16(const uint8*& buf) {
+  uint16 x = (static_cast<uint16>(buf[0]))      |
+             (static_cast<uint16>(buf[1]) << 8);
+  buf += sizeof(x);
+  return x;
+}
+
+static uint32 ReadUint32(const uint8*& buf) {
+  uint32 x = (static_cast<uint32>(buf[0]))       |
+             (static_cast<uint32>(buf[1]) << 8)  |
+             (static_cast<uint32>(buf[2]) << 16) |
+             (static_cast<uint32>(buf[3]) << 24);
+  buf += sizeof(x);
+  return x;
+}
+
+//-----------------------------------------------------------------------------
+
+static void ZapBuf(void* buf, size_t buf_len) {
+  memset(buf, 0, buf_len);
+}
+
+// TODO(wtc): Can we implement ZapString as
+// s.replace(0, s.size(), s.size(), '\0)?
+static void ZapString(std::string* s) {
+  ZapBuf(&(*s)[0], s->length());
+}
+
+static void ZapString(string16* s) {
+  ZapBuf(&(*s)[0], s->length() * 2);
+}
+
+// LM_Hash computes the LM hash of the given password.
+//
+// param password
+//       unicode password.
+// param hash
+//       16-byte result buffer
+//
+// Note: This function is not being used because our SendLM() function always
+// returns false.
+static void LM_Hash(const string16& password, uint8* hash) {
+  static const uint8 LM_MAGIC[] = "KGS!@#$%";
+
+  // Convert password to OEM character set.  We'll just use the native
+  // filesystem charset.
+  std::string passbuf = base::SysWideToNativeMB(UTF16ToWide(password));
+  StringToUpperASCII(&passbuf);
+  passbuf.resize(14, '\0');
+
+  uint8 k1[8], k2[8];
+  DESMakeKey(reinterpret_cast<const uint8*>(passbuf.data())    , k1);
+  DESMakeKey(reinterpret_cast<const uint8*>(passbuf.data()) + 7, k2);
+  ZapString(&passbuf);
+
+  // Use password keys to hash LM magic string twice.
+  DESEncrypt(k1, LM_MAGIC, hash);
+  DESEncrypt(k2, LM_MAGIC, hash + 8);
+}
+
+// NTLM_Hash computes the NTLM hash of the given password.
+//
+// param password
+//       null-terminated unicode password.
+// param hash
+//       16-byte result buffer
+static void NTLM_Hash(const string16& password, uint8* hash) {
+#ifdef IS_BIG_ENDIAN
+  uint32 len = password.length();
+  uint8* passbuf;
+
+  passbuf = static_cast<uint8*>(malloc(len * 2));
+  WriteUnicodeLE(passbuf, password.data(), len);
+  weak_crypto::MD4Sum(passbuf, len * 2, hash);
+
+  ZapBuf(passbuf, len * 2);
+  free(passbuf);
+#else
+  weak_crypto::MD4Sum(reinterpret_cast<const uint8*>(password.data()),
+                      password.length() * 2, hash);
+#endif
+}
+
+//-----------------------------------------------------------------------------
+
+// LM_Response generates the LM response given a 16-byte password hash and the
+// challenge from the Type-2 message.
+//
+// param hash
+//       16-byte password hash
+// param challenge
+//       8-byte challenge from Type-2 message
+// param response
+//       24-byte buffer to contain the LM response upon return
+static void LM_Response(const uint8* hash,
+                        const uint8* challenge,
+                        uint8* response) {
+  uint8 keybytes[21], k1[8], k2[8], k3[8];
+
+  memcpy(keybytes, hash, 16);
+  ZapBuf(keybytes + 16, 5);
+
+  DESMakeKey(keybytes     , k1);
+  DESMakeKey(keybytes +  7, k2);
+  DESMakeKey(keybytes + 14, k3);
+
+  DESEncrypt(k1, challenge, response);
+  DESEncrypt(k2, challenge, response + 8);
+  DESEncrypt(k3, challenge, response + 16);
+}
+
+//-----------------------------------------------------------------------------
+
+// Returns OK or a network error code.
+static int GenerateType1Msg(void** out_buf, uint32* out_len) {
+  //
+  // Verify that buf_len is sufficient.
+  //
+  *out_len = NTLM_TYPE1_HEADER_LEN;
+  *out_buf = malloc(*out_len);
+  if (!*out_buf)
+    return ERR_OUT_OF_MEMORY;
+
+  //
+  // Write out type 1 message.
+  //
+  void* cursor = *out_buf;
+
+  // 0 : signature
+  cursor = WriteBytes(cursor, NTLM_SIGNATURE, sizeof(NTLM_SIGNATURE));
+
+  // 8 : marker
+  cursor = WriteBytes(cursor, NTLM_TYPE1_MARKER, sizeof(NTLM_TYPE1_MARKER));
+
+  // 12 : flags
+  cursor = WriteDWORD(cursor, NTLM_TYPE1_FLAGS);
+
+  //
+  // NOTE: It is common for the domain and workstation fields to be empty.
+  //       This is true of Win2k clients, and my guess is that there is
+  //       little utility to sending these strings before the charset has
+  //       been negotiated.  We follow suite -- anyways, it doesn't hurt
+  //       to save some bytes on the wire ;-)
+  //
+
+  // 16 : supplied domain security buffer (empty)
+  cursor = WriteSecBuf(cursor, 0, 0);
+
+  // 24 : supplied workstation security buffer (empty)
+  cursor = WriteSecBuf(cursor, 0, 0);
+
+  return OK;
+}
+
+struct Type2Msg {
+  uint32      flags;         // NTLM_Xxx bitwise combination
+  uint8       challenge[8];  // 8 byte challenge
+  const void* target;        // target string (type depends on flags)
+  uint32      target_len;    // target length in bytes
+};
+
+// Returns OK or a network error code.
+// TODO(wtc): This function returns ERR_UNEXPECTED when the input message is
+// invalid.  We should return a better error code.
+static int ParseType2Msg(const void* in_buf, uint32 in_len, Type2Msg* msg) {
+  // Make sure in_buf is long enough to contain a meaningful type2 msg.
+  //
+  // 0  NTLMSSP Signature
+  // 8  NTLM Message Type
+  // 12 Target Name
+  // 20 Flags
+  // 24 Challenge
+  // 32 end of header, start of optional data blocks
+  //
+  if (in_len < NTLM_TYPE2_HEADER_LEN)
+    return ERR_UNEXPECTED;
+
+  const uint8* cursor = (const uint8*) in_buf;
+
+  // verify NTLMSSP signature
+  if (memcmp(cursor, NTLM_SIGNATURE, sizeof(NTLM_SIGNATURE)) != 0)
+    return ERR_UNEXPECTED;
+  cursor += sizeof(NTLM_SIGNATURE);
+
+  // verify Type-2 marker
+  if (memcmp(cursor, NTLM_TYPE2_MARKER, sizeof(NTLM_TYPE2_MARKER)) != 0)
+    return ERR_UNEXPECTED;
+  cursor += sizeof(NTLM_TYPE2_MARKER);
+
+  // read target name security buffer
+  msg->target_len = ReadUint16(cursor);
+  ReadUint16(cursor);  // discard next 16-bit value
+  uint32 offset = ReadUint32(cursor);  // get offset from in_buf
+  msg->target = ((const uint8*) in_buf) + offset;
+
+  // read flags
+  msg->flags = ReadUint32(cursor);
+
+  // read challenge
+  memcpy(msg->challenge, cursor, sizeof(msg->challenge));
+  cursor += sizeof(msg->challenge);
+
+  NTLM_LOG(("NTLM type 2 message:\n"));
+  LogBuf("target", (const uint8*) msg->target, msg->target_len);
+  LogBuf("flags", (const uint8*) &msg->flags, 4);
+  LogFlags(msg->flags);
+  LogBuf("challenge", msg->challenge, sizeof(msg->challenge));
+
+  // We currently do not implement LMv2/NTLMv2 or NTLM2 responses,
+  // so we can ignore target information.  We may want to enable
+  // support for these alternate mechanisms in the future.
+  return OK;
+}
+
+// Returns OK or a network error code.
+static int GenerateType3Msg(const string16& domain,
+                            const string16& username,
+                            const string16& password,
+                            const void*     in_buf,
+                            uint32          in_len,
+                            void**          out_buf,
+                            uint32*         out_len) {
+  // in_buf contains Type-2 msg (the challenge) from server.
+
+  int rv;
+  Type2Msg msg;
+
+  rv = ParseType2Msg(in_buf, in_len, &msg);
+  if (rv != OK)
+    return rv;
+
+  bool unicode = (msg.flags & NTLM_NegotiateUnicode) != 0;
+
+  // Temporary buffers for unicode strings
+#ifdef IS_BIG_ENDIAN
+  string16 ucs_domain_buf, ucs_user_buf;
+#endif
+  string16 ucs_host_buf;
+  // Temporary buffers for oem strings
+  std::string oem_domain_buf, oem_user_buf, oem_host_buf;
+  // Pointers and lengths for the string buffers; encoding is unicode if
+  // the "negotiate unicode" flag was set in the Type-2 message.
+  const void* domain_ptr;
+  const void* user_ptr;
+  const void* host_ptr;
+  uint32 domain_len, user_len, host_len;
+
+  //
+  // Get domain name.
+  //
+  if (unicode) {
+#ifdef IS_BIG_ENDIAN
+    ucs_domain_buf = domain;
+    domain_ptr = ucs_domain_buf.data();
+    domain_len = ucs_domain_buf.length() * 2;
+    WriteUnicodeLE(const_cast<void*>(domain_ptr), (const char16*) domain_ptr,
+                   ucs_domain_buf.length());
+#else
+    domain_ptr = domain.data();
+    domain_len = domain.length() * 2;
+#endif
+  } else {
+    oem_domain_buf = base::SysWideToNativeMB(UTF16ToWide(domain));
+    domain_ptr = oem_domain_buf.data();
+    domain_len = oem_domain_buf.length();
+  }
+
+  //
+  // Get user name.
+  //
+  if (unicode) {
+#ifdef IS_BIG_ENDIAN
+    ucs_user_buf = username;
+    user_ptr = ucs_user_buf.data();
+    user_len = ucs_user_buf.length() * 2;
+    WriteUnicodeLE(const_cast<void*>(user_ptr), (const char16*) user_ptr,
+                   ucs_user_buf.length());
+#else
+    user_ptr = username.data();
+    user_len = username.length() * 2;
+#endif
+  } else {
+    oem_user_buf = base::SysWideToNativeMB(UTF16ToWide(username));
+    user_ptr = oem_user_buf.data();
+    user_len = oem_user_buf.length();
+  }
+
+  //
+  // Get workstation name (use local machine's hostname).
+  //
+  char host_buf[256];  // Host names are limited to 255 bytes.
+  if (gethostname(host_buf, sizeof(host_buf)) != 0)
+    return ERR_UNEXPECTED;
+  host_len = strlen(host_buf);
+  if (unicode) {
+    // hostname is ASCII, so we can do a simple zero-pad expansion:
+    ucs_host_buf.assign(host_buf, host_buf + host_len);
+    host_ptr = ucs_host_buf.data();
+    host_len = ucs_host_buf.length() * 2;
+#ifdef IS_BIG_ENDIAN
+    WriteUnicodeLE(const_cast<void*>(host_ptr), (const char16*) host_ptr,
+                   ucs_host_buf.length());
+#endif
+  } else {
+    host_ptr = host_buf;
+  }
+
+  //
+  // Now that we have generated all of the strings, we can allocate out_buf.
+  //
+  *out_len = NTLM_TYPE3_HEADER_LEN + host_len + domain_len + user_len +
+             LM_RESP_LEN + NTLM_RESP_LEN;
+  *out_buf = malloc(*out_len);
+  if (!*out_buf)
+    return ERR_OUT_OF_MEMORY;
+
+  //
+  // Next, we compute the LM and NTLM responses.
+  //
+  uint8 lm_resp[LM_RESP_LEN];
+  uint8 ntlm_resp[NTLM_RESP_LEN];
+  uint8 ntlm_hash[NTLM_HASH_LEN];
+  if (msg.flags & NTLM_NegotiateNTLM2Key) {
+    // compute NTLM2 session response
+    MD5Digest session_hash;
+    uint8 temp[16];
+
+    // TODO(wtc): Add a function that generates random bytes so we can say:
+    //   GenerateRandom(lm_resp, 8);
+    for (int i = 0; i < 8; ++i)
+      lm_resp[i] = base::RandInt(0, 255);
+    memset(lm_resp + 8, 0, LM_RESP_LEN - 8);
+
+    memcpy(temp, msg.challenge, 8);
+    memcpy(temp + 8, lm_resp, 8);
+    MD5Sum(temp, 16, &session_hash);
+
+    NTLM_Hash(password, ntlm_hash);
+    LM_Response(ntlm_hash, session_hash.a, ntlm_resp);
+  } else {
+    NTLM_Hash(password, ntlm_hash);
+    LM_Response(ntlm_hash, msg.challenge, ntlm_resp);
+
+    if (SendLM()) {
+      uint8 lm_hash[LM_HASH_LEN];
+      LM_Hash(password, lm_hash);
+      LM_Response(lm_hash, msg.challenge, lm_resp);
+    } else {
+      // According to http://davenport.sourceforge.net/ntlm.html#ntlmVersion2,
+      // the correct way to not send the LM hash is to send the NTLM hash twice
+      // in both the LM and NTLM response fields.
+      LM_Response(ntlm_hash, msg.challenge, lm_resp);
+    }
+  }
+
+  //
+  // Finally, we assemble the Type-3 msg :-)
+  //
+  void* cursor = *out_buf;
+  uint32 offset;
+
+  // 0 : signature
+  cursor = WriteBytes(cursor, NTLM_SIGNATURE, sizeof(NTLM_SIGNATURE));
+
+  // 8 : marker
+  cursor = WriteBytes(cursor, NTLM_TYPE3_MARKER, sizeof(NTLM_TYPE3_MARKER));
+
+  // 12 : LM response sec buf
+  offset = NTLM_TYPE3_HEADER_LEN + domain_len + user_len + host_len;
+  cursor = WriteSecBuf(cursor, LM_RESP_LEN, offset);
+  memcpy(static_cast<uint8*>(*out_buf) + offset, lm_resp, LM_RESP_LEN);
+
+  // 20 : NTLM response sec buf
+  offset += LM_RESP_LEN;
+  cursor = WriteSecBuf(cursor, NTLM_RESP_LEN, offset);
+  memcpy(static_cast<uint8*>(*out_buf) + offset, ntlm_resp, NTLM_RESP_LEN);
+
+  // 28 : domain name sec buf
+  offset = NTLM_TYPE3_HEADER_LEN;
+  cursor = WriteSecBuf(cursor, domain_len, offset);
+  memcpy(static_cast<uint8*>(*out_buf) + offset, domain_ptr, domain_len);
+
+  // 36 : user name sec buf
+  offset += domain_len;
+  cursor = WriteSecBuf(cursor, user_len, offset);
+  memcpy(static_cast<uint8*>(*out_buf) + offset, user_ptr, user_len);
+
+  // 44 : workstation (host) name sec buf
+  offset += user_len;
+  cursor = WriteSecBuf(cursor, host_len, offset);
+  memcpy(static_cast<uint8*>(*out_buf) + offset, host_ptr, host_len);
+
+  // 52 : session key sec buf (not used)
+  cursor = WriteSecBuf(cursor, 0, 0);
+
+  // 60 : negotiated flags
+  cursor = WriteDWORD(cursor, msg.flags & NTLM_TYPE1_FLAGS);
+
+  return OK;
+}
+
+//-----------------------------------------------------------------------------
+
+class NTLMAuthModule {
+ public:
+  NTLMAuthModule() {}
+
+  ~NTLMAuthModule();
+
+  int Init(const string16& domain,
+           const string16& username,
+           const string16& password);
+
+  int GetNextToken(const void* in_token,
+                   uint32 in_token_len,
+                   void** out_token,
+                   uint32* out_token_len);
+
+ private:
+  string16 domain_;
+  string16 username_;
+  string16 password_;
+};
+
+NTLMAuthModule::~NTLMAuthModule() {
+  ZapString(&password_);
+}
+
+int NTLMAuthModule::Init(const string16& domain,
+                         const string16& username,
+                         const string16& password) {
+  domain_ = domain;
+  username_ = username;
+  password_ = password;
+  return OK;
+}
+
+int NTLMAuthModule::GetNextToken(const void* in_token,
+                                 uint32 in_token_len,
+                                 void** out_token,
+                                 uint32* out_token_len) {
+  int rv;
+
+  // If in_token is non-null, then assume it contains a type 2 message...
+  if (in_token) {
+    LogToken("in-token", in_token, in_token_len);
+    rv = GenerateType3Msg(domain_, username_, password_, in_token,
+                          in_token_len, out_token, out_token_len);
+  } else {
+    rv = GenerateType1Msg(out_token, out_token_len);
+  }
+
+  if (rv == OK)
+    LogToken("out-token", *out_token, *out_token_len);
+
+  return rv;
+}
+
+// NTLM authentication is specified in "NTLM Over HTTP Protocol Specification"
+// [MS-NTHT].
+
+HttpAuthHandlerNTLM::HttpAuthHandlerNTLM()
+    : ntlm_module_(new NTLMAuthModule) {
+}
+
+HttpAuthHandlerNTLM::~HttpAuthHandlerNTLM() {
+}
+
+bool HttpAuthHandlerNTLM::NeedsIdentity() {
+  return !auth_data_.empty();
+}
+
+std::string HttpAuthHandlerNTLM::GenerateCredentials(
+    const std::wstring& username,
+    const std::wstring& password,
+    const HttpRequestInfo* request,
+    const ProxyInfo* proxy) {
+  int rv;
+  // TODO(wtc): See if we can use char* instead of void* for in_buf and
+  // out_buf.  This change will need to propagate to GetNextToken,
+  // GenerateType1Msg, and GenerateType3Msg, and perhaps further.
+  const void* in_buf;
+  void* out_buf;
+  uint32 in_buf_len, out_buf_len;
+  std::string decoded_auth_data;
+
+  // |username| may be in the form "DOMAIN\user".  Parse it into the two
+  // components.
+  std::wstring domain;
+  std::wstring user;
+  size_t backslash_idx = username.find(L'\\');
+  if (backslash_idx == std::wstring::npos) {
+    user = username;
+  } else {
+    domain = username.substr(0, backslash_idx);
+    user = username.substr(backslash_idx + 1);
+  }
+  rv = ntlm_module_->Init(WideToUTF16(domain), WideToUTF16(user),
+                          WideToUTF16(password));
+
+  // Initial challenge.
+  if (auth_data_.empty()) {
+    in_buf_len = 0;
+    in_buf = NULL;
+  } else {
+    // Decode |auth_data_| into the input buffer.
+    int len = auth_data_.length();
+
+    // Strip off any padding.
+    // (See https://bugzilla.mozilla.org/show_bug.cgi?id=230351.)
+    //
+    // Our base64 decoder requires that the length be a multiple of 4.
+    while (len > 0 && len % 4 != 0 && auth_data_[len - 1] == '=')
+      len--;
+    auth_data_.erase(len);
+
+    if (!Base64Decode(auth_data_, &decoded_auth_data))
+      return std::string();  // Improper base64 encoding
+    in_buf_len = decoded_auth_data.length();
+    in_buf = decoded_auth_data.data();
+  }
+
+  rv = ntlm_module_->GetNextToken(in_buf, in_buf_len, &out_buf, &out_buf_len);
+  if (rv != OK)
+    return std::string();
+
+  // Base64 encode data in output buffer and prepend "NTLM ".
+  std::string encode_input(static_cast<char*>(out_buf), out_buf_len);
+  std::string encode_output;
+  bool ok = Base64Encode(encode_input, &encode_output);
+  // OK, we are done with |out_buf|
+  free(out_buf);
+  if (!ok)
+    return std::string();
+  return std::string("NTLM ") + encode_output;
+}
+
+// The NTLM challenge header looks like:
+//   WWW-Authenticate: NTLM auth-data
+bool HttpAuthHandlerNTLM::ParseChallenge(
+    std::string::const_iterator challenge_begin,
+    std::string::const_iterator challenge_end) {
+  scheme_ = "ntlm";
+  score_ = 3;
+  properties_ = ENCRYPTS_IDENTITY | IS_CONNECTION_BASED;
+  auth_data_.clear();
+
+  // Verify the challenge's auth-scheme.
+  HttpAuth::ChallengeTokenizer challenge_tok(challenge_begin, challenge_end);
+  if (!challenge_tok.valid() ||
+      !LowerCaseEqualsASCII(challenge_tok.scheme(), "ntlm"))
+    return false;
+
+  // Extract the auth-data.  We can't use challenge_tok.GetNext() because
+  // auth-data is base64-encoded and may contain '=' padding at the end,
+  // which would be mistaken for a name=value pair.
+  challenge_begin += 4;  // Skip over "NTLM".
+  HttpUtil::TrimLWS(&challenge_begin, &challenge_end);
+
+  auth_data_.assign(challenge_begin, challenge_end);
+
+  return true;
+}
+
+}  // namespace net