/* vim:set ts=2 sw=2 et cindent: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "nsNTLMAuthModule.h"

#include <time.h>

#include "ScopedNSSTypes.h"
#include "md4.h"
#include "mozilla/Assertions.h"
#include "mozilla/Base64.h"
#include "mozilla/Casting.h"
#include "mozilla/CheckedInt.h"
#include "mozilla/EndianUtils.h"
#include "mozilla/Likely.h"
#include "mozilla/Logging.h"
#include "mozilla/Preferences.h"
#include "mozilla/Sprintf.h"
#include "mozilla/StaticPrefs_network.h"
#include "mozilla/Telemetry.h"
#include "nsCOMPtr.h"
#include "nsComponentManagerUtils.h"
#include "nsICryptoHash.h"
#include "nsNativeCharsetUtils.h"
#include "nsNetCID.h"
#include "nsUnicharUtils.h"
#include "pk11pub.h"
#include "prsystem.h"

static mozilla::LazyLogModule sNTLMLog("NTLM");

#define LOG(x) MOZ_LOG(sNTLMLog, mozilla::LogLevel::Debug, x)
#define LOG_ENABLED() MOZ_LOG_TEST(sNTLMLog, mozilla::LogLevel::Debug)

static void des_makekey(const uint8_t* raw, uint8_t* key);
static void des_encrypt(const uint8_t* key, const uint8_t* src, uint8_t* hash);

//-----------------------------------------------------------------------------
// this file contains a cross-platform NTLM authentication implementation. it
// is based on documentation from: http://davenport.sourceforge.net/ntlm.html
//-----------------------------------------------------------------------------

#define NTLM_NegotiateUnicode 0x00000001
#define NTLM_NegotiateOEM 0x00000002
#define NTLM_RequestTarget 0x00000004
#define NTLM_Unknown1 0x00000008
#define NTLM_NegotiateSign 0x00000010
#define NTLM_NegotiateSeal 0x00000020
#define NTLM_NegotiateDatagramStyle 0x00000040
#define NTLM_NegotiateLanManagerKey 0x00000080
#define NTLM_NegotiateNetware 0x00000100
#define NTLM_NegotiateNTLMKey 0x00000200
#define NTLM_Unknown2 0x00000400
#define NTLM_Unknown3 0x00000800
#define NTLM_NegotiateDomainSupplied 0x00001000
#define NTLM_NegotiateWorkstationSupplied 0x00002000
#define NTLM_NegotiateLocalCall 0x00004000
#define NTLM_NegotiateAlwaysSign 0x00008000
#define NTLM_TargetTypeDomain 0x00010000
#define NTLM_TargetTypeServer 0x00020000
#define NTLM_TargetTypeShare 0x00040000
#define NTLM_NegotiateNTLM2Key 0x00080000
#define NTLM_RequestInitResponse 0x00100000
#define NTLM_RequestAcceptResponse 0x00200000
#define NTLM_RequestNonNTSessionKey 0x00400000
#define NTLM_NegotiateTargetInfo 0x00800000
#define NTLM_Unknown4 0x01000000
#define NTLM_Unknown5 0x02000000
#define NTLM_Unknown6 0x04000000
#define NTLM_Unknown7 0x08000000
#define NTLM_Unknown8 0x10000000
#define NTLM_Negotiate128 0x20000000
#define NTLM_NegotiateKeyExchange 0x40000000
#define NTLM_Negotiate56 0x80000000

// we send these flags with our type 1 message
#define 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};

#define NTLM_TYPE1_HEADER_LEN 32
#define NTLM_TYPE2_HEADER_LEN 48
#define NTLM_TYPE3_HEADER_LEN 64

/**
 * We don't actually send a LM response, but we still have to send something in
 * this spot
 */
#define LM_RESP_LEN 24

#define NTLM_CHAL_LEN 8

#define NTLM_HASH_LEN 16
#define NTLMv2_HASH_LEN 16
#define NTLM_RESP_LEN 24
#define NTLMv2_RESP_LEN 16
#define NTLMv2_BLOB1_LEN 28

//-----------------------------------------------------------------------------

/**
 * Prints a description of flags to the NSPR Log, if enabled.
 */
static void LogFlags(uint32_t flags) {
  if (!LOG_ENABLED()) return;
#define TEST(_flag)         \
  if (flags & NTLM_##_flag) \
  PR_LogPrint("    0x%08x (" #_flag ")\n", NTLM_##_flag)

  TEST(NegotiateUnicode);
  TEST(NegotiateOEM);
  TEST(RequestTarget);
  TEST(Unknown1);
  TEST(NegotiateSign);
  TEST(NegotiateSeal);
  TEST(NegotiateDatagramStyle);
  TEST(NegotiateLanManagerKey);
  TEST(NegotiateNetware);
  TEST(NegotiateNTLMKey);
  TEST(Unknown2);
  TEST(Unknown3);
  TEST(NegotiateDomainSupplied);
  TEST(NegotiateWorkstationSupplied);
  TEST(NegotiateLocalCall);
  TEST(NegotiateAlwaysSign);
  TEST(TargetTypeDomain);
  TEST(TargetTypeServer);
  TEST(TargetTypeShare);
  TEST(NegotiateNTLM2Key);
  TEST(RequestInitResponse);
  TEST(RequestAcceptResponse);
  TEST(RequestNonNTSessionKey);
  TEST(NegotiateTargetInfo);
  TEST(Unknown4);
  TEST(Unknown5);
  TEST(Unknown6);
  TEST(Unknown7);
  TEST(Unknown8);
  TEST(Negotiate128);
  TEST(NegotiateKeyExchange);
  TEST(Negotiate56);

#undef TEST
}

/**
 * Prints a hexdump of buf to the NSPR Log, if enabled.
 * @param tag Description of the data, will be printed in front of the data
 * @param buf the data to print
 * @param bufLen length of the data
 */
static void LogBuf(const char* tag, const uint8_t* buf, uint32_t bufLen) {
  int i;

  if (!LOG_ENABLED()) return;

  PR_LogPrint("%s =\n", tag);
  char line[80];
  while (bufLen > 0) {
    int count = bufLen;
    if (count > 8) count = 8;

    strcpy(line, "    ");
    for (i = 0; i < count; ++i) {
      int len = strlen(line);
      snprintf(line + len, sizeof(line) - len, "0x%02x ", int(buf[i]));
    }
    for (; i < 8; ++i) {
      int len = strlen(line);
      snprintf(line + len, sizeof(line) - len, "     ");
    }

    int len = strlen(line);
    snprintf(line + len, sizeof(line) - len, "   ");
    for (i = 0; i < count; ++i) {
      len = strlen(line);
      if (isprint(buf[i])) {
        snprintf(line + len, sizeof(line) - len, "%c", buf[i]);
      } else {
        snprintf(line + len, sizeof(line) - len, ".");
      }
    }
    PR_LogPrint("%s\n", line);

    bufLen -= count;
    buf += count;
  }
}

/**
 * Print base64-encoded token to the NSPR Log.
 * @param name Description of the token, will be printed in front
 * @param token The token to print
 * @param tokenLen length of the data in token
 */
static void LogToken(const char* name, const void* token, uint32_t tokenLen) {
  if (!LOG_ENABLED()) {
    return;
  }

  nsDependentCSubstring tokenString(static_cast<const char*>(token), tokenLen);
  nsAutoCString base64Token;
  nsresult rv = mozilla::Base64Encode(tokenString, base64Token);
  if (NS_FAILED(rv)) {
    return;
  }

  PR_LogPrint("%s: %s\n", name, base64Token.get());
}

//-----------------------------------------------------------------------------

// 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_t dataLen) {
  memcpy(buf, data, dataLen);
  return (uint8_t*)buf + dataLen;
}

static void* WriteDWORD(void* buf, uint32_t 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_t length, uint32_t 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_t* str, uint32_t strLen) {
  // convert input string from BE to LE
  uint8_t *cursor = (uint8_t*)buf, *input = (uint8_t*)str;
  for (uint32_t i = 0; i < strLen; ++i, input += 2, cursor += 2) {
    // allow for the case where |buf == str|
    uint8_t temp = input[0];
    cursor[0] = input[1];
    cursor[1] = temp;
  }
  return buf;
}
#endif

static uint16_t ReadUint16(const uint8_t*& buf) {
  uint16_t x = ((uint16_t)buf[0]) | ((uint16_t)buf[1] << 8);
  buf += sizeof(x);
  return x;
}

static uint32_t ReadUint32(const uint8_t*& buf) {
  uint32_t x = ((uint32_t)buf[0]) | (((uint32_t)buf[1]) << 8) |
               (((uint32_t)buf[2]) << 16) | (((uint32_t)buf[3]) << 24);
  buf += sizeof(x);
  return x;
}

//-----------------------------------------------------------------------------

static void ZapBuf(void* buf, size_t bufLen) { memset(buf, 0, bufLen); }

static void ZapString(nsString& s) { ZapBuf(s.BeginWriting(), s.Length() * 2); }

/**
 * 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 nsString& password, unsigned char* hash) {
  uint32_t len = password.Length();
  uint8_t* passbuf;

#ifdef IS_BIG_ENDIAN
  passbuf = (uint8_t*)malloc(len * 2);
  WriteUnicodeLE(passbuf, password.get(), len);
#else
  passbuf = (uint8_t*)password.get();
#endif

  md4sum(passbuf, len * 2, hash);

#ifdef IS_BIG_ENDIAN
  ZapBuf(passbuf, len * 2);
  free(passbuf);
#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_t* hash, const uint8_t* challenge,
                        uint8_t* response) {
  uint8_t keybytes[21], k1[8], k2[8], k3[8];

  memcpy(keybytes, hash, 16);
  ZapBuf(keybytes + 16, 5);

  des_makekey(keybytes, k1);
  des_makekey(keybytes + 7, k2);
  des_makekey(keybytes + 14, k3);

  des_encrypt(k1, challenge, response);
  des_encrypt(k2, challenge, response + 8);
  des_encrypt(k3, challenge, response + 16);
}

//-----------------------------------------------------------------------------

static nsresult GenerateType1Msg(void** outBuf, uint32_t* outLen) {
  //
  // verify that bufLen is sufficient
  //
  *outLen = NTLM_TYPE1_HEADER_LEN;
  *outBuf = moz_xmalloc(*outLen);

  //
  // write out type 1 msg
  //
  void* cursor = *outBuf;

  // 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 NS_OK;
}

struct Type2Msg {
  uint32_t flags;                    // NTLM_Xxx bitwise combination
  uint8_t challenge[NTLM_CHAL_LEN];  // 8 byte challenge
  const uint8_t* target;             // target string (type depends on flags)
  uint32_t targetLen;                // target length in bytes
  const uint8_t*
      targetInfo;          // target Attribute-Value pairs (DNS domain, et al)
  uint32_t targetInfoLen;  // target AV pairs length in bytes
};

static nsresult ParseType2Msg(const void* inBuf, uint32_t inLen,
                              Type2Msg* msg) {
  // make sure inBuf is long enough to contain a meaningful type2 msg.
  //
  // 0  NTLMSSP Signature
  // 8  NTLM Message Type
  // 12 Target Name
  // 20 Flags
  // 24 Challenge
  // 32 targetInfo
  // 48 start of optional data blocks
  //
  if (inLen < NTLM_TYPE2_HEADER_LEN) return NS_ERROR_UNEXPECTED;

  const auto* cursor = static_cast<const uint8_t*>(inBuf);

  // verify NTLMSSP signature
  if (memcmp(cursor, NTLM_SIGNATURE, sizeof(NTLM_SIGNATURE)) != 0) {
    return NS_ERROR_UNEXPECTED;
  }

  cursor += sizeof(NTLM_SIGNATURE);

  // verify Type-2 marker
  if (memcmp(cursor, NTLM_TYPE2_MARKER, sizeof(NTLM_TYPE2_MARKER)) != 0) {
    return NS_ERROR_UNEXPECTED;
  }

  cursor += sizeof(NTLM_TYPE2_MARKER);

  // Read target name security buffer: ...
  // ... read target length.
  uint32_t targetLen = ReadUint16(cursor);
  // ... skip next 16-bit "allocated space" value.
  ReadUint16(cursor);
  // ... read offset from inBuf.
  uint32_t offset = ReadUint32(cursor);
  mozilla::CheckedInt<uint32_t> targetEnd = offset;
  targetEnd += targetLen;
  // Check the offset / length combo is in range of the input buffer, including
  // integer overflow checking.
  if (MOZ_LIKELY(targetEnd.isValid() && targetEnd.value() <= inLen)) {
    msg->targetLen = targetLen;
    msg->target = static_cast<const uint8_t*>(inBuf) + offset;
  } else {
    // Do not error out, for (conservative) backward compatibility.
    msg->targetLen = 0;
    msg->target = nullptr;
  }

  // read flags
  msg->flags = ReadUint32(cursor);

  // read challenge
  memcpy(msg->challenge, cursor, sizeof(msg->challenge));
  cursor += sizeof(msg->challenge);

  LOG(("NTLM type 2 message:\n"));
  LogBuf("target", msg->target, msg->targetLen);
  LogBuf("flags",
         mozilla::BitwiseCast<const uint8_t*, const uint32_t*>(&msg->flags), 4);
  LogFlags(msg->flags);
  LogBuf("challenge", msg->challenge, sizeof(msg->challenge));

  // Read (and skip) the reserved field
  ReadUint32(cursor);
  ReadUint32(cursor);
  // Read target name security buffer: ...
  // ... read target length.
  uint32_t targetInfoLen = ReadUint16(cursor);
  // ... skip next 16-bit "allocated space" value.
  ReadUint16(cursor);
  // ... read offset from inBuf.
  offset = ReadUint32(cursor);
  mozilla::CheckedInt<uint32_t> targetInfoEnd = offset;
  targetInfoEnd += targetInfoLen;
  // Check the offset / length combo is in range of the input buffer, including
  // integer overflow checking.
  if (MOZ_LIKELY(targetInfoEnd.isValid() && targetInfoEnd.value() <= inLen)) {
    msg->targetInfoLen = targetInfoLen;
    msg->targetInfo = static_cast<const uint8_t*>(inBuf) + offset;
  } else {
    NS_ERROR("failed to get NTLMv2 target info");
    return NS_ERROR_UNEXPECTED;
  }

  return NS_OK;
}

static nsresult GenerateType3Msg(const nsString& domain,
                                 const nsString& username,
                                 const nsString& password, const void* inBuf,
                                 uint32_t inLen, void** outBuf,
                                 uint32_t* outLen) {
  // inBuf contains Type-2 msg (the challenge) from server
  MOZ_ASSERT(NS_IsMainThread());
  nsresult rv;
  Type2Msg msg{};

  rv = ParseType2Msg(inBuf, inLen, &msg);
  if (NS_FAILED(rv)) return rv;

  bool unicode = (msg.flags & NTLM_NegotiateUnicode);

  // There is no negotiation for NTLMv2, so we just do it unless we are forced
  // by explict user configuration to use the older DES-based cryptography.
  bool ntlmv2 = !mozilla::StaticPrefs::network_auth_force_generic_ntlm_v1();

  // temporary buffers for unicode strings
#ifdef IS_BIG_ENDIAN
  nsAutoString ucsDomainBuf, ucsUserBuf;
#endif
  nsAutoCString hostBuf;
  nsAutoString ucsHostBuf;
  // temporary buffers for oem strings
  nsAutoCString oemDomainBuf, oemUserBuf, oemHostBuf;
  // pointers and lengths for the string buffers; encoding is unicode if
  // the "negotiate unicode" flag was set in the Type-2 message.
  const void *domainPtr, *userPtr, *hostPtr;
  uint32_t domainLen, userLen, hostLen;

  // This is for NTLM, for NTLMv2 we set the new full length once we know it
  mozilla::CheckedInt<uint16_t> ntlmRespLen = NTLM_RESP_LEN;

  //
  // get domain name
  //
  if (unicode) {
#ifdef IS_BIG_ENDIAN
    ucsDomainBuf = domain;
    domainPtr = ucsDomainBuf.get();
    domainLen = ucsDomainBuf.Length() * 2;
    WriteUnicodeLE(const_cast<void*>(domainPtr),
                   static_cast<const char16_t*>(domainPtr),
                   ucsDomainBuf.Length());
#else
    domainPtr = domain.get();
    domainLen = domain.Length() * 2;
#endif
  } else {
    NS_CopyUnicodeToNative(domain, oemDomainBuf);
    domainPtr = oemDomainBuf.get();
    domainLen = oemDomainBuf.Length();
  }

  //
  // get user name
  //
  if (unicode) {
#ifdef IS_BIG_ENDIAN
    ucsUserBuf = username;
    userPtr = ucsUserBuf.get();
    userLen = ucsUserBuf.Length() * 2;
    WriteUnicodeLE(const_cast<void*>(userPtr),
                   static_cast<const char16_t*>(userPtr), ucsUserBuf.Length());
#else
    userPtr = username.get();
    userLen = username.Length() * 2;
#endif
  } else {
    NS_CopyUnicodeToNative(username, oemUserBuf);
    userPtr = oemUserBuf.get();
    userLen = oemUserBuf.Length();
  }

  //
  // get workstation name
  // (do not use local machine's hostname after bug 1046421)
  //
  rv = mozilla::Preferences::GetCString("network.generic-ntlm-auth.workstation",
                                        hostBuf);
  if (NS_FAILED(rv)) {
    return rv;
  }

  if (unicode) {
    CopyUTF8toUTF16(hostBuf, ucsHostBuf);
    hostPtr = ucsHostBuf.get();
    hostLen = ucsHostBuf.Length() * 2;
#ifdef IS_BIG_ENDIAN
    WriteUnicodeLE(const_cast<void*>(hostPtr),
                   static_cast<const char16_t*>(hostPtr), ucsHostBuf.Length());
#endif
  } else {
    hostPtr = hostBuf.get();
    hostLen = hostBuf.Length();
  }

  //
  // now that we have generated all of the strings, we can allocate outBuf.
  //
  //
  // next, we compute the NTLM or NTLM2 responses.
  //
  uint8_t lmResp[LM_RESP_LEN];
  uint8_t ntlmResp[NTLM_RESP_LEN];
  uint8_t ntlmv2Resp[NTLMv2_RESP_LEN];
  uint8_t ntlmHash[NTLM_HASH_LEN];
  uint8_t ntlmv2_blob1[NTLMv2_BLOB1_LEN];
  if (ntlmv2) {
    // NTLMv2 mode, the default
    nsString userUpper, domainUpper;

    // temporary buffers for unicode strings
    nsAutoString ucsDomainUpperBuf;
    nsAutoString ucsUserUpperBuf;
    const void* domainUpperPtr;
    const void* userUpperPtr;
    uint32_t domainUpperLen;
    uint32_t userUpperLen;

    if (msg.targetInfoLen == 0) {
      NS_ERROR("failed to get NTLMv2 target info, can not do NTLMv2");
      return NS_ERROR_UNEXPECTED;
    }

    ToUpperCase(username, ucsUserUpperBuf);
    userUpperPtr = ucsUserUpperBuf.get();
    userUpperLen = ucsUserUpperBuf.Length() * 2;
#ifdef IS_BIG_ENDIAN
    WriteUnicodeLE(const_cast<void*>(userUpperPtr),
                   static_cast<const char16_t*>(userUpperPtr),
                   ucsUserUpperBuf.Length());
#endif
    ToUpperCase(domain, ucsDomainUpperBuf);
    domainUpperPtr = ucsDomainUpperBuf.get();
    domainUpperLen = ucsDomainUpperBuf.Length() * 2;
#ifdef IS_BIG_ENDIAN
    WriteUnicodeLE(const_cast<void*>(domainUpperPtr),
                   static_cast<const char16_t*>(domainUpperPtr),
                   ucsDomainUpperBuf.Length());
#endif

    NTLM_Hash(password, ntlmHash);

    HMAC ntlmv2HashHmac;
    rv = ntlmv2HashHmac.Begin(SEC_OID_MD5, Span(ntlmHash, NTLM_HASH_LEN));
    if (NS_FAILED(rv)) {
      return rv;
    }
    rv = ntlmv2HashHmac.Update(static_cast<const uint8_t*>(userUpperPtr),
                               userUpperLen);
    if (NS_FAILED(rv)) {
      return rv;
    }
    rv = ntlmv2HashHmac.Update(static_cast<const uint8_t*>(domainUpperPtr),
                               domainUpperLen);
    if (NS_FAILED(rv)) {
      return rv;
    }
    nsTArray<uint8_t> ntlmv2Hash;
    rv = ntlmv2HashHmac.End(ntlmv2Hash);
    if (NS_FAILED(rv)) {
      return rv;
    }

    uint8_t client_random[NTLM_CHAL_LEN];
    PK11_GenerateRandom(client_random, NTLM_CHAL_LEN);

    HMAC lmv2ResponseHmac;
    rv = lmv2ResponseHmac.Begin(SEC_OID_MD5, Span(ntlmv2Hash));
    if (NS_FAILED(rv)) {
      return rv;
    }
    rv = lmv2ResponseHmac.Update(msg.challenge, NTLM_CHAL_LEN);
    if (NS_FAILED(rv)) {
      return rv;
    }
    rv = lmv2ResponseHmac.Update(client_random, NTLM_CHAL_LEN);
    if (NS_FAILED(rv)) {
      return rv;
    }
    nsTArray<uint8_t> lmv2Response;
    rv = lmv2ResponseHmac.End(lmv2Response);
    if (NS_FAILED(rv)) {
      return rv;
    }

    if (lmv2Response.Length() != NTLMv2_HASH_LEN) {
      return NS_ERROR_UNEXPECTED;
    }

    memcpy(lmResp, lmv2Response.Elements(), NTLMv2_HASH_LEN);
    memcpy(lmResp + NTLMv2_HASH_LEN, client_random, NTLM_CHAL_LEN);

    memset(ntlmv2_blob1, 0, NTLMv2_BLOB1_LEN);

    time_t unix_time;
    uint64_t nt_time = time(&unix_time);
    nt_time += 11644473600LL;     // Number of seconds betwen 1601 and 1970
    nt_time *= 1000 * 1000 * 10;  // Convert seconds to 100 ns units

    ntlmv2_blob1[0] = 1;
    ntlmv2_blob1[1] = 1;
    mozilla::LittleEndian::writeUint64(&ntlmv2_blob1[8], nt_time);
    PK11_GenerateRandom(&ntlmv2_blob1[16], NTLM_CHAL_LEN);

    HMAC ntlmv2ResponseHmac;
    rv = ntlmv2ResponseHmac.Begin(SEC_OID_MD5, Span(ntlmv2Hash));
    if (NS_FAILED(rv)) {
      return rv;
    }
    rv = ntlmv2ResponseHmac.Update(msg.challenge, NTLM_CHAL_LEN);
    if (NS_FAILED(rv)) {
      return rv;
    }
    rv = ntlmv2ResponseHmac.Update(ntlmv2_blob1, NTLMv2_BLOB1_LEN);
    if (NS_FAILED(rv)) {
      return rv;
    }
    rv = ntlmv2ResponseHmac.Update(msg.targetInfo, msg.targetInfoLen);
    if (NS_FAILED(rv)) {
      return rv;
    }
    nsTArray<uint8_t> ntlmv2Response;
    rv = ntlmv2ResponseHmac.End(ntlmv2Response);
    if (NS_FAILED(rv)) {
      return rv;
    }

    if (ntlmv2Response.Length() != NTLMv2_RESP_LEN) {
      return NS_ERROR_UNEXPECTED;
    }

    memcpy(ntlmv2Resp, ntlmv2Response.Elements(), NTLMv2_RESP_LEN);
    ntlmRespLen = NTLMv2_RESP_LEN + NTLMv2_BLOB1_LEN;
    ntlmRespLen += msg.targetInfoLen;
    if (!ntlmRespLen.isValid()) {
      NS_ERROR("failed to do NTLMv2: integer overflow?!?");
      return NS_ERROR_UNEXPECTED;
    }
  } else if (msg.flags & NTLM_NegotiateNTLM2Key) {
    // compute NTLM2 session response
    nsCString sessionHashString;

    PK11_GenerateRandom(lmResp, NTLM_CHAL_LEN);
    memset(lmResp + NTLM_CHAL_LEN, 0, LM_RESP_LEN - NTLM_CHAL_LEN);

    nsCOMPtr<nsICryptoHash> hasher =
        do_CreateInstance(NS_CRYPTO_HASH_CONTRACTID, &rv);
    if (NS_FAILED(rv)) {
      return rv;
    }
    rv = hasher->Init(nsICryptoHash::MD5);
    if (NS_FAILED(rv)) {
      return rv;
    }
    rv = hasher->Update(msg.challenge, NTLM_CHAL_LEN);
    if (NS_FAILED(rv)) {
      return rv;
    }
    rv = hasher->Update(lmResp, NTLM_CHAL_LEN);
    if (NS_FAILED(rv)) {
      return rv;
    }
    rv = hasher->Finish(false, sessionHashString);
    if (NS_FAILED(rv)) {
      return rv;
    }

    const auto* sessionHash = mozilla::BitwiseCast<const uint8_t*, const char*>(
        sessionHashString.get());

    LogBuf("NTLM2 effective key: ", sessionHash, 8);

    NTLM_Hash(password, ntlmHash);
    LM_Response(ntlmHash, sessionHash, ntlmResp);
  } else {
    NTLM_Hash(password, ntlmHash);
    LM_Response(ntlmHash, msg.challenge, ntlmResp);

    // 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(ntlmHash, msg.challenge, lmResp);
  }

  mozilla::CheckedInt<uint32_t> totalLen = NTLM_TYPE3_HEADER_LEN + LM_RESP_LEN;
  totalLen += hostLen;
  totalLen += domainLen;
  totalLen += userLen;
  totalLen += ntlmRespLen.value();

  if (!totalLen.isValid()) {
    NS_ERROR("failed preparing to allocate NTLM response: integer overflow?!?");
    return NS_ERROR_FAILURE;
  }
  *outBuf = moz_xmalloc(totalLen.value());
  *outLen = totalLen.value();

  //
  // finally, we assemble the Type-3 msg :-)
  //
  void* cursor = *outBuf;
  mozilla::CheckedInt<uint32_t> 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;
  offset += domainLen;
  offset += userLen;
  offset += hostLen;
  if (!offset.isValid()) {
    NS_ERROR("failed preparing to write NTLM response: integer overflow?!?");
    return NS_ERROR_UNEXPECTED;
  }
  cursor = WriteSecBuf(cursor, LM_RESP_LEN, offset.value());
  memcpy(static_cast<uint8_t*>(*outBuf) + offset.value(), lmResp, LM_RESP_LEN);

  // 20 : NTLM or NTLMv2 response sec buf
  offset += LM_RESP_LEN;
  if (!offset.isValid()) {
    NS_ERROR("failed preparing to write NTLM response: integer overflow?!?");
    return NS_ERROR_UNEXPECTED;
  }
  cursor = WriteSecBuf(cursor, ntlmRespLen.value(), offset.value());
  if (ntlmv2) {
    memcpy(static_cast<uint8_t*>(*outBuf) + offset.value(), ntlmv2Resp,
           NTLMv2_RESP_LEN);
    offset += NTLMv2_RESP_LEN;
    if (!offset.isValid()) {
      NS_ERROR("failed preparing to write NTLM response: integer overflow?!?");
      return NS_ERROR_UNEXPECTED;
    }
    memcpy(static_cast<uint8_t*>(*outBuf) + offset.value(), ntlmv2_blob1,
           NTLMv2_BLOB1_LEN);
    offset += NTLMv2_BLOB1_LEN;
    if (!offset.isValid()) {
      NS_ERROR("failed preparing to write NTLM response: integer overflow?!?");
      return NS_ERROR_UNEXPECTED;
    }
    memcpy(static_cast<uint8_t*>(*outBuf) + offset.value(), msg.targetInfo,
           msg.targetInfoLen);
  } else {
    memcpy(static_cast<uint8_t*>(*outBuf) + offset.value(), ntlmResp,
           NTLM_RESP_LEN);
  }
  // 28 : domain name sec buf
  offset = NTLM_TYPE3_HEADER_LEN;
  cursor = WriteSecBuf(cursor, domainLen, offset.value());
  memcpy(static_cast<uint8_t*>(*outBuf) + offset.value(), domainPtr, domainLen);

  // 36 : user name sec buf
  offset += domainLen;
  if (!offset.isValid()) {
    NS_ERROR("failed preparing to write NTLM response: integer overflow?!?");
    return NS_ERROR_UNEXPECTED;
  }
  cursor = WriteSecBuf(cursor, userLen, offset.value());
  memcpy(static_cast<uint8_t*>(*outBuf) + offset.value(), userPtr, userLen);

  // 44 : workstation (host) name sec buf
  offset += userLen;
  if (!offset.isValid()) {
    NS_ERROR("failed preparing to write NTLM response: integer overflow?!?");
    return NS_ERROR_UNEXPECTED;
  }
  cursor = WriteSecBuf(cursor, hostLen, offset.value());
  memcpy(static_cast<uint8_t*>(*outBuf) + offset.value(), hostPtr, hostLen);

  // 52 : session key sec buf (not used)
  cursor = WriteSecBuf(cursor, 0, 0);

  // 60 : negotiated flags
  cursor = WriteDWORD(cursor, msg.flags & NTLM_TYPE1_FLAGS);

  return NS_OK;
}

//-----------------------------------------------------------------------------

NS_IMPL_ISUPPORTS(nsNTLMAuthModule, nsIAuthModule)

nsNTLMAuthModule::~nsNTLMAuthModule() { ZapString(mPassword); }

nsresult nsNTLMAuthModule::InitTest() {
  // disable NTLM authentication when FIPS mode is enabled.
  return PK11_IsFIPS() ? NS_ERROR_NOT_AVAILABLE : NS_OK;
}

NS_IMETHODIMP
nsNTLMAuthModule::Init(const nsACString& serviceName, uint32_t serviceFlags,
                       const nsAString& domain, const nsAString& username,
                       const nsAString& password) {
  MOZ_ASSERT((serviceFlags & ~nsIAuthModule::REQ_PROXY_AUTH) ==
                 nsIAuthModule::REQ_DEFAULT,
             "Unexpected service flags");

  mDomain = domain;
  mUsername = username;
  mPassword = password;
  mNTLMNegotiateSent = false;

  static bool sTelemetrySent = false;
  if (!sTelemetrySent) {
    mozilla::Telemetry::Accumulate(mozilla::Telemetry::NTLM_MODULE_USED_2,
                                   serviceFlags & nsIAuthModule::REQ_PROXY_AUTH
                                       ? NTLM_MODULE_GENERIC_PROXY
                                       : NTLM_MODULE_GENERIC_DIRECT);
    sTelemetrySent = true;
  }

  return NS_OK;
}

NS_IMETHODIMP
nsNTLMAuthModule::GetNextToken(const void* inToken, uint32_t inTokenLen,
                               void** outToken, uint32_t* outTokenLen) {
  nsresult rv;

  // disable NTLM authentication when FIPS mode is enabled.
  if (PK11_IsFIPS()) {
    return NS_ERROR_NOT_AVAILABLE;
  }

  if (mNTLMNegotiateSent) {
    // if inToken is non-null, and we have sent the NTLMSSP_NEGOTIATE (type 1),
    // then the NTLMSSP_CHALLENGE (type 2) is expected
    if (inToken) {
      LogToken("in-token", inToken, inTokenLen);
      // Now generate the NTLMSSP_AUTH (type 3)
      rv = GenerateType3Msg(mDomain, mUsername, mPassword, inToken, inTokenLen,
                            outToken, outTokenLen);
    } else {
      LOG(
          ("NTLMSSP_NEGOTIATE already sent and presumably "
           "rejected by the server, refusing to send another"));
      rv = NS_ERROR_UNEXPECTED;
    }
  } else {
    if (inToken) {
      LOG(("NTLMSSP_NEGOTIATE not sent but NTLM reply already received?!?"));
      rv = NS_ERROR_UNEXPECTED;
    } else {
      rv = GenerateType1Msg(outToken, outTokenLen);
      if (NS_SUCCEEDED(rv)) {
        mNTLMNegotiateSent = true;
      }
    }
  }

  if (NS_SUCCEEDED(rv)) LogToken("out-token", *outToken, *outTokenLen);

  return rv;
}

NS_IMETHODIMP
nsNTLMAuthModule::Unwrap(const void* inToken, uint32_t inTokenLen,
                         void** outToken, uint32_t* outTokenLen) {
  return NS_ERROR_NOT_IMPLEMENTED;
}

NS_IMETHODIMP
nsNTLMAuthModule::Wrap(const void* inToken, uint32_t inTokenLen,
                       bool confidential, void** outToken,
                       uint32_t* outTokenLen) {
  return NS_ERROR_NOT_IMPLEMENTED;
}

//-----------------------------------------------------------------------------
// DES support code

// set odd parity bit (in least significant bit position)
static uint8_t des_setkeyparity(uint8_t x) {
  if ((((x >> 7) ^ (x >> 6) ^ (x >> 5) ^ (x >> 4) ^ (x >> 3) ^ (x >> 2) ^
        (x >> 1)) &
       0x01) == 0) {
    x |= 0x01;
  } else {
    x &= 0xfe;
  }
  return x;
}

// build 64-bit des key from 56-bit raw key
static void des_makekey(const uint8_t* raw, uint8_t* key) {
  key[0] = des_setkeyparity(raw[0]);
  key[1] = des_setkeyparity((raw[0] << 7) | (raw[1] >> 1));
  key[2] = des_setkeyparity((raw[1] << 6) | (raw[2] >> 2));
  key[3] = des_setkeyparity((raw[2] << 5) | (raw[3] >> 3));
  key[4] = des_setkeyparity((raw[3] << 4) | (raw[4] >> 4));
  key[5] = des_setkeyparity((raw[4] << 3) | (raw[5] >> 5));
  key[6] = des_setkeyparity((raw[5] << 2) | (raw[6] >> 6));
  key[7] = des_setkeyparity((raw[6] << 1));
}

// run des encryption algorithm (using NSS)
static void des_encrypt(const uint8_t* key, const uint8_t* src, uint8_t* hash) {
  CK_MECHANISM_TYPE cipherMech = CKM_DES_ECB;
  PK11SymKey* symkey = nullptr;
  PK11Context* ctxt = nullptr;
  SECItem keyItem;
  mozilla::UniqueSECItem param;
  SECStatus rv;
  unsigned int n;

  mozilla::UniquePK11SlotInfo slot(PK11_GetBestSlot(cipherMech, nullptr));
  if (!slot) {
    NS_ERROR("no slot");
    goto done;
  }

  keyItem.data = const_cast<uint8_t*>(key);
  keyItem.len = 8;
  symkey = PK11_ImportSymKey(slot.get(), cipherMech, PK11_OriginUnwrap,
                             CKA_ENCRYPT, &keyItem, nullptr);
  if (!symkey) {
    NS_ERROR("no symkey");
    goto done;
  }

  // no initialization vector required
  param = mozilla::UniqueSECItem(PK11_ParamFromIV(cipherMech, nullptr));
  if (!param) {
    NS_ERROR("no param");
    goto done;
  }

  ctxt =
      PK11_CreateContextBySymKey(cipherMech, CKA_ENCRYPT, symkey, param.get());
  if (!ctxt) {
    NS_ERROR("no context");
    goto done;
  }

  rv = PK11_CipherOp(ctxt, hash, (int*)&n, 8, (uint8_t*)src, 8);
  if (rv != SECSuccess) {
    NS_ERROR("des failure");
    goto done;
  }

  rv = PK11_DigestFinal(ctxt, hash + 8, &n, 0);
  if (rv != SECSuccess) {
    NS_ERROR("des failure");
    goto done;
  }

done:
  if (ctxt) PK11_DestroyContext(ctxt, true);
  if (symkey) PK11_FreeSymKey(symkey);
}