1 files changed, 464 insertions, 0 deletions
diff --git a/toolkit/mozapps/update/common/updatecommon.cpp b/toolkit/mozapps/update/common/updatecommon.cpp
new file mode 100644
index 0000000000..e270d71b7e
--- /dev/null
+++ b/toolkit/mozapps/update/common/updatecommon.cpp
@@ -0,0 +1,464 @@
+/* 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/. */
+
+#if defined(XP_WIN)
+#  include <windows.h>
+#  include <winioctl.h>  // for FSCTL_GET_REPARSE_POINT
+#  include <shlobj.h>
+#  ifndef RRF_SUBKEY_WOW6464KEY
+#    define RRF_SUBKEY_WOW6464KEY 0x00010000
+#  endif
+#endif
+
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <stdarg.h>
+
+#include "updatecommon.h"
+#ifdef XP_WIN
+#  include "updatehelper.h"
+#  include "nsWindowsHelpers.h"
+#  include "mozilla/UniquePtr.h"
+#  include "mozilla/WinHeaderOnlyUtils.h"
+
+// This struct isn't in any SDK header, so this definition was copied from:
+// https://docs.microsoft.com/en-us/windows-hardware/drivers/ddi/content/ntifs/ns-ntifs-_reparse_data_buffer
+typedef struct _REPARSE_DATA_BUFFER {
+  ULONG ReparseTag;
+  USHORT ReparseDataLength;
+  USHORT Reserved;
+  union {
+    struct {
+      USHORT SubstituteNameOffset;
+      USHORT SubstituteNameLength;
+      USHORT PrintNameOffset;
+      USHORT PrintNameLength;
+      ULONG Flags;
+      WCHAR PathBuffer[1];
+    } SymbolicLinkReparseBuffer;
+    struct {
+      USHORT SubstituteNameOffset;
+      USHORT SubstituteNameLength;
+      USHORT PrintNameOffset;
+      USHORT PrintNameLength;
+      WCHAR PathBuffer[1];
+    } MountPointReparseBuffer;
+    struct {
+      UCHAR DataBuffer[1];
+    } GenericReparseBuffer;
+  } DUMMYUNIONNAME;
+} REPARSE_DATA_BUFFER, *PREPARSE_DATA_BUFFER;
+#endif
+
+UpdateLog::UpdateLog() : logFP(nullptr) {}
+
+void UpdateLog::Init(NS_tchar* logFilePath) {
+  if (logFP) {
+    return;
+  }
+
+  // When the path is over the length limit disable logging by not opening the
+  // file and not setting logFP.
+  int dstFilePathLen = NS_tstrlen(logFilePath);
+  if (dstFilePathLen > 0 && dstFilePathLen < MAXPATHLEN - 1) {
+    NS_tstrncpy(mDstFilePath, logFilePath, MAXPATHLEN);
+#if defined(XP_WIN) || defined(XP_MACOSX)
+    logFP = NS_tfopen(mDstFilePath, NS_T("w"));
+#else
+    // On platforms that have an updates directory in the installation directory
+    // (e.g. platforms other than Windows and Mac) the update log is written to
+    // a temporary file and then to the update log file. This is needed since
+    // the installation directory is moved during a replace request. This can be
+    // removed when the platform's updates directory is located outside of the
+    // installation directory.
+    logFP = tmpfile();
+#endif
+  }
+}
+
+void UpdateLog::Finish() {
+  if (!logFP) {
+    return;
+  }
+
+#if !defined(XP_WIN) && !defined(XP_MACOSX)
+  const int blockSize = 1024;
+  char buffer[blockSize];
+  fflush(logFP);
+  rewind(logFP);
+
+  FILE* updateLogFP = NS_tfopen(mDstFilePath, NS_T("wb+"));
+  while (!feof(logFP)) {
+    size_t read = fread(buffer, 1, blockSize, logFP);
+    if (ferror(logFP)) {
+      fclose(logFP);
+      logFP = nullptr;
+      fclose(updateLogFP);
+      updateLogFP = nullptr;
+      return;
+    }
+
+    size_t written = 0;
+
+    while (written < read) {
+      size_t chunkWritten = fwrite(buffer, 1, read - written, updateLogFP);
+      if (chunkWritten <= 0) {
+        fclose(logFP);
+        logFP = nullptr;
+        fclose(updateLogFP);
+        updateLogFP = nullptr;
+        return;
+      }
+
+      written += chunkWritten;
+    }
+  }
+  fclose(updateLogFP);
+  updateLogFP = nullptr;
+#endif
+
+  fclose(logFP);
+  logFP = nullptr;
+}
+
+void UpdateLog::Flush() {
+  if (!logFP) {
+    return;
+  }
+
+  fflush(logFP);
+}
+
+void UpdateLog::Printf(const char* fmt, ...) {
+  if (!logFP) {
+    return;
+  }
+
+  va_list ap;
+  va_start(ap, fmt);
+  vfprintf(logFP, fmt, ap);
+  fprintf(logFP, "\n");
+  va_end(ap);
+#if defined(XP_WIN) && defined(MOZ_DEBUG)
+  // When the updater crashes on Windows the log file won't be flushed and this
+  // can make it easier to debug what is going on.
+  fflush(logFP);
+#endif
+}
+
+void UpdateLog::WarnPrintf(const char* fmt, ...) {
+  if (!logFP) {
+    return;
+  }
+
+  va_list ap;
+  va_start(ap, fmt);
+  fprintf(logFP, "*** Warning: ");
+  vfprintf(logFP, fmt, ap);
+  fprintf(logFP, "***\n");
+  va_end(ap);
+#if defined(XP_WIN) && defined(MOZ_DEBUG)
+  // When the updater crashes on Windows the log file won't be flushed and this
+  // can make it easier to debug what is going on.
+  fflush(logFP);
+#endif
+}
+
+#ifdef XP_WIN
+/**
+ * Determine if a path contains symlinks or junctions to disallowed locations
+ *
+ * @param fullPath  The full path to check.
+ * @return true if the path contains invalid links or on errors,
+ *         false if the check passes and the path can be used
+ */
+bool PathContainsInvalidLinks(wchar_t* const fullPath) {
+  wchar_t pathCopy[MAXPATHLEN + 1] = L"";
+  wcsncpy(pathCopy, fullPath, MAXPATHLEN);
+  wchar_t* remainingPath = nullptr;
+  wchar_t* nextToken = wcstok_s(pathCopy, L"\\", &remainingPath);
+  wchar_t* partialPath = nextToken;
+
+  while (nextToken) {
+    if ((GetFileAttributesW(partialPath) & FILE_ATTRIBUTE_REPARSE_POINT) != 0) {
+      nsAutoHandle h(CreateFileW(
+          partialPath, 0,
+          FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, nullptr,
+          OPEN_EXISTING,
+          FILE_FLAG_BACKUP_SEMANTICS | FILE_FLAG_OPEN_REPARSE_POINT, nullptr));
+      if (h == INVALID_HANDLE_VALUE) {
+        if (GetLastError() == ERROR_FILE_NOT_FOUND) {
+          // The path can't be an invalid link if it doesn't exist.
+          return false;
+        } else {
+          return true;
+        }
+      }
+
+      mozilla::UniquePtr<UINT8[]> byteBuffer =
+          mozilla::MakeUnique<UINT8[]>(MAXIMUM_REPARSE_DATA_BUFFER_SIZE);
+      if (!byteBuffer) {
+        return true;
+      }
+      ZeroMemory(byteBuffer.get(), MAXIMUM_REPARSE_DATA_BUFFER_SIZE);
+      REPARSE_DATA_BUFFER* buffer = (REPARSE_DATA_BUFFER*)byteBuffer.get();
+      DWORD bytes = 0;
+      if (!DeviceIoControl(h, FSCTL_GET_REPARSE_POINT, nullptr, 0, buffer,
+                           MAXIMUM_REPARSE_DATA_BUFFER_SIZE, &bytes, nullptr)) {
+        return true;
+      }
+
+      wchar_t* reparseTarget = nullptr;
+      switch (buffer->ReparseTag) {
+        case IO_REPARSE_TAG_MOUNT_POINT:
+          reparseTarget =
+              buffer->MountPointReparseBuffer.PathBuffer +
+              (buffer->MountPointReparseBuffer.SubstituteNameOffset /
+               sizeof(wchar_t));
+          if (buffer->MountPointReparseBuffer.SubstituteNameLength <
+              ARRAYSIZE(L"\\??\\")) {
+            return false;
+          }
+          break;
+        case IO_REPARSE_TAG_SYMLINK:
+          reparseTarget =
+              buffer->SymbolicLinkReparseBuffer.PathBuffer +
+              (buffer->SymbolicLinkReparseBuffer.SubstituteNameOffset /
+               sizeof(wchar_t));
+          if (buffer->SymbolicLinkReparseBuffer.SubstituteNameLength <
+              ARRAYSIZE(L"\\??\\")) {
+            return false;
+          }
+          break;
+        default:
+          return true;
+          break;
+      }
+
+      if (!reparseTarget) {
+        return false;
+      }
+      if (wcsncmp(reparseTarget, L"\\??\\", ARRAYSIZE(L"\\??\\") - 1) != 0) {
+        return true;
+      }
+    }
+
+    nextToken = wcstok_s(nullptr, L"\\", &remainingPath);
+    PathAppendW(partialPath, nextToken);
+  }
+
+  return false;
+}
+
+/**
+ * Determine if a path is located within Program Files, either native or x86
+ *
+ * @param fullPath  The full path to check.
+ * @return true if fullPath begins with either Program Files directory,
+ *         false if it does not or if an error is encountered
+ */
+bool IsProgramFilesPath(NS_tchar* fullPath) {
+  // Make sure we don't try to compare against a short path.
+  DWORD longInstallPathChars = GetLongPathNameW(fullPath, nullptr, 0);
+  if (longInstallPathChars == 0) {
+    return false;
+  }
+  mozilla::UniquePtr<wchar_t[]> longInstallPath =
+      mozilla::MakeUnique<wchar_t[]>(longInstallPathChars);
+  if (!longInstallPath || !GetLongPathNameW(fullPath, longInstallPath.get(),
+                                            longInstallPathChars)) {
+    return false;
+  }
+
+  // First check for Program Files (x86).
+  {
+    PWSTR programFiles32PathRaw = nullptr;
+    // FOLDERID_ProgramFilesX86 gets native Program Files directory on a 32-bit
+    // OS or the (x86) directory on a 64-bit OS regardless of this binary's
+    // bitness.
+    if (FAILED(SHGetKnownFolderPath(FOLDERID_ProgramFilesX86, 0, nullptr,
+                                    &programFiles32PathRaw))) {
+      // That call should never fail on any supported OS version.
+      return false;
+    }
+    mozilla::UniquePtr<wchar_t, mozilla::CoTaskMemFreeDeleter>
+        programFiles32Path(programFiles32PathRaw);
+    // We need this path to have a trailing slash so our prefix test doesn't
+    // match on a different folder which happens to have a name beginning with
+    // the prefix we're looking for but then also more characters after that.
+    size_t length = wcslen(programFiles32Path.get());
+    if (length == 0) {
+      return false;
+    }
+    if (programFiles32Path.get()[length - 1] == L'\\') {
+      if (wcsnicmp(longInstallPath.get(), programFiles32Path.get(), length) ==
+          0) {
+        return true;
+      }
+    } else {
+      // Allocate space for a copy of the string along with a terminator and one
+      // extra character for the trailing backslash.
+      length += 1;
+      mozilla::UniquePtr<wchar_t[]> programFiles32PathWithSlash =
+          mozilla::MakeUnique<wchar_t[]>(length + 1);
+      if (!programFiles32PathWithSlash) {
+        return false;
+      }
+
+      NS_tsnprintf(programFiles32PathWithSlash.get(), length + 1, NS_T("%s\\"),
+                   programFiles32Path.get());
+
+      if (wcsnicmp(longInstallPath.get(), programFiles32PathWithSlash.get(),
+                   length) == 0) {
+        return true;
+      }
+    }
+  }
+
+  // If we didn't find (x86), check for the native Program Files.
+  {
+    // In case we're a 32-bit binary on 64-bit Windows, we now have a problem
+    // getting the right "native" Program Files path, which is that there is no
+    // FOLDERID_* value that returns that path. So we always read that one out
+    // of its canonical registry location instead. If we're on a 32-bit OS, this
+    // will be the same path that we just checked. First get the buffer size to
+    // allocate for the path.
+    DWORD length = 0;
+    if (RegGetValueW(HKEY_LOCAL_MACHINE,
+                     L"Software\\Microsoft\\Windows\\CurrentVersion",
+                     L"ProgramFilesDir", RRF_RT_REG_SZ | RRF_SUBKEY_WOW6464KEY,
+                     nullptr, nullptr, &length) != ERROR_SUCCESS) {
+      return false;
+    }
+    // RegGetValue returns the length including the terminator, but it's in
+    // bytes, so convert that to characters.
+    DWORD lengthChars = (length / sizeof(wchar_t));
+    if (lengthChars <= 1) {
+      return false;
+    }
+    mozilla::UniquePtr<wchar_t[]> programFilesNativePath =
+        mozilla::MakeUnique<wchar_t[]>(lengthChars);
+    if (!programFilesNativePath) {
+      return false;
+    }
+
+    // Now actually read the value.
+    if (RegGetValueW(
+            HKEY_LOCAL_MACHINE, L"Software\\Microsoft\\Windows\\CurrentVersion",
+            L"ProgramFilesDir", RRF_RT_REG_SZ | RRF_SUBKEY_WOW6464KEY, nullptr,
+            programFilesNativePath.get(), &length) != ERROR_SUCCESS) {
+      return false;
+    }
+    size_t nativePathStrLen =
+        wcsnlen_s(programFilesNativePath.get(), lengthChars);
+    if (nativePathStrLen == 0) {
+      return false;
+    }
+
+    // As before, append a backslash if there isn't one already.
+    if (programFilesNativePath.get()[nativePathStrLen - 1] == L'\\') {
+      if (wcsnicmp(longInstallPath.get(), programFilesNativePath.get(),
+                   nativePathStrLen) == 0) {
+        return true;
+      }
+    } else {
+      // Allocate space for a copy of the string along with a terminator and one
+      // extra character for the trailing backslash.
+      nativePathStrLen += 1;
+      mozilla::UniquePtr<wchar_t[]> programFilesNativePathWithSlash =
+          mozilla::MakeUnique<wchar_t[]>(nativePathStrLen + 1);
+      if (!programFilesNativePathWithSlash) {
+        return false;
+      }
+
+      NS_tsnprintf(programFilesNativePathWithSlash.get(), nativePathStrLen + 1,
+                   NS_T("%s\\"), programFilesNativePath.get());
+
+      if (wcsnicmp(longInstallPath.get(), programFilesNativePathWithSlash.get(),
+                   nativePathStrLen) == 0) {
+        return true;
+      }
+    }
+  }
+
+  return false;
+}
+#endif
+
+/**
+ * Performs checks of a full path for validity for this application.
+ *
+ * @param  origFullPath
+ *         The full path to check.
+ * @return true if the path is valid for this application and false otherwise.
+ */
+bool IsValidFullPath(NS_tchar* origFullPath) {
+  // Subtract 1 from MAXPATHLEN for null termination.
+  if (NS_tstrlen(origFullPath) > MAXPATHLEN - 1) {
+    // The path is longer than acceptable for this application.
+    return false;
+  }
+
+#ifdef XP_WIN
+  NS_tchar testPath[MAXPATHLEN] = {NS_T('\0')};
+  // GetFullPathNameW will replace / with \ which PathCanonicalizeW requires.
+  if (GetFullPathNameW(origFullPath, MAXPATHLEN, testPath, nullptr) == 0) {
+    // Unable to get the full name for the path (e.g. invalid path).
+    return false;
+  }
+
+  NS_tchar canonicalPath[MAXPATHLEN] = {NS_T('\0')};
+  if (!PathCanonicalizeW(canonicalPath, testPath)) {
+    // Path could not be canonicalized (e.g. invalid path).
+    return false;
+  }
+
+  // Check if the path passed in resolves to a differerent path.
+  if (NS_tstricmp(origFullPath, canonicalPath) != 0) {
+    // Case insensitive string comparison between the supplied path and the
+    // canonical path are not equal. This will prevent directory traversal and
+    // the use of / in paths since they are converted to \.
+    return false;
+  }
+
+  NS_tstrncpy(testPath, origFullPath, MAXPATHLEN);
+  if (!PathStripToRootW(testPath)) {
+    // It should always be possible to strip a valid path to its root.
+    return false;
+  }
+
+  if (origFullPath[0] == NS_T('\\')) {
+    // Only allow UNC server share paths.
+    if (!PathIsUNCServerShareW(testPath)) {
+      return false;
+    }
+  }
+
+  if (PathContainsInvalidLinks(canonicalPath)) {
+    return false;
+  }
+#else
+  // Only allow full paths.
+  if (origFullPath[0] != NS_T('/')) {
+    return false;
+  }
+
+  // The path must not traverse directories
+  if (NS_tstrstr(origFullPath, NS_T("/../")) != nullptr) {
+    return false;
+  }
+
+  // The path shall not have a path traversal suffix
+  const NS_tchar invalidSuffix[] = NS_T("/..");
+  size_t pathLen = NS_tstrlen(origFullPath);
+  size_t invalidSuffixLen = NS_tstrlen(invalidSuffix);
+  if (invalidSuffixLen <= pathLen &&
+      NS_tstrncmp(origFullPath + pathLen - invalidSuffixLen, invalidSuffix,
+                  invalidSuffixLen) == 0) {
+    return false;
+  }
+#endif
+  return true;
+}