Move app_installer into chromium.

third_party/omaha/src/base/extractor.cc

+// Copyright 2005-2009 Google Inc.
+//
+// Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+// ========================================================================
+
+#include "extractor.h"
+
+#include <windows.h>
+#include <wintrust.h>
+#include <crtdbg.h>
+#pragma warning(push)
+// C4100: unreferenced formal parameter
+// C4310: cast truncates constant value
+// C4548: expression before comma has no effect
+#pragma warning(disable : 4100 4310 4548)
+#include "base/basictypes.h"
+#pragma warning(pop)
+
+namespace omaha {
+
+#define AFFILIATE_ID_MAGIC "Gact"
+
+TagExtractor::TagExtractor()
+    : file_handle_(INVALID_HANDLE_VALUE),
+      file_mapping_(NULL),
+      file_base_(NULL),
+      file_length_(0),
+      cert_length_(0),
+      cert_dir_base_(NULL) {
+}
+
+TagExtractor::~TagExtractor() {
+  CloseFile();
+}
+
+bool TagExtractor::OpenFile(const TCHAR* filename) {
+  CloseFile();
+  file_handle_ = CreateFile(filename, GENERIC_READ, FILE_SHARE_READ, NULL,
+    OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
+  if (IsFileOpen()) {
+    file_mapping_ = CreateFileMapping(file_handle_, NULL, PAGE_READONLY,
+      0, 0, NULL);
+    if (file_mapping_ != NULL) {
+      file_base_ = MapViewOfFile(file_mapping_, FILE_MAP_READ, 0, 0, 0);
+      if (file_base_ != NULL) {
+        MEMORY_BASIC_INFORMATION info = {0};
+        if (::VirtualQuery(file_base_, &info, sizeof(info))) {
+          file_length_ = info.RegionSize;
+          return true;
+        }
+      }
+      CloseHandle(file_mapping_);
+    }
+    CloseFile();
+  }
+  return false;
+}
+
+bool TagExtractor::IsFileOpen() const {
+  return file_handle_ != INVALID_HANDLE_VALUE;
+}
+
+void TagExtractor::CloseFile() {
+  if (file_base_ != NULL) {
+    UnmapViewOfFile(file_base_);
+    file_base_ = NULL;
+  }
+  if (file_mapping_ != NULL) {
+    CloseHandle(file_mapping_);
+    file_mapping_ = NULL;
+  }
+  if (IsFileOpen()) {
+    CloseHandle(file_handle_);
+    file_handle_ = INVALID_HANDLE_VALUE;
+  }
+}
+
+bool TagExtractor::ExtractTag(const char* binary_file,
+                              size_t binary_file_length,
+                              char* tag_buffer,
+                              int* tag_buffer_len) {
+  file_length_ = binary_file_length;
+  return InternalExtractTag(binary_file, tag_buffer, tag_buffer_len);
+}
+
+bool TagExtractor::ExtractTag(char* tag_buffer, int* tag_buffer_len) {
+  if (tag_buffer_len == NULL) {
+    return false;
+  }
+  if (!IsFileOpen()) {
+    return false;
+  }
+
+  return InternalExtractTag(static_cast<char*>(file_base_),
+                            tag_buffer,
+                            tag_buffer_len);
+}
+
+bool TagExtractor::InternalReadCertificate(const char* file_buffer) {
+  if (!file_buffer) {
+    return false;
+  }
+
+  const void* certificate_directory_pointer =
+    GetCertificateDirectoryPointer(file_buffer);
+  if (NULL == certificate_directory_pointer) {
+    return false;
+  }
+  const void* asn1_signature_pointer =
+    GetASN1SignaturePointer(certificate_directory_pointer);
+  if (NULL == asn1_signature_pointer) {
+    return false;
+  }
+  DWORD asn1_signature_length =
+    GetASN1SignatureLength(asn1_signature_pointer);
+  if (0 == asn1_signature_length) {
+    return false;
+  }
+
+  cert_length_ = asn1_signature_length;
+  cert_dir_base_ = certificate_directory_pointer;
+
+  return true;
+}
+
+bool TagExtractor::InternalExtractTag(const char* file_buffer,
+                                      char* tag_buffer,
+                                      int* tag_buffer_len) {
+  if (!file_buffer) {
+    return false;
+  }
+
+  if (!InternalReadCertificate(file_buffer)) {
+    return false;
+  }
+
+  const char* read_base = static_cast<const char*>(cert_dir_base_) +
+                          cert_length_;
+  if (read_base >= file_buffer + file_length_) {
+    // The file is not tagged.
+    return false;
+  }
+
+  return ReadTag(read_base, tag_buffer, tag_buffer_len);
+}
+
+bool TagExtractor::ReadTag(const char* tag_pointer,
+                           char* tag_buffer,
+                           int* tag_buffer_len) const {
+  int mc = memcmp(tag_pointer,
+                  AFFILIATE_ID_MAGIC,
+                  arraysize(AFFILIATE_ID_MAGIC) - 1);
+  if (0 != mc) {
+    return false;
+  }
+  tag_pointer += arraysize(AFFILIATE_ID_MAGIC) - 1;
+
+  uint16 id_len = 0;
+  const unsigned char* id_len_serialized =
+    reinterpret_cast<const unsigned char*>(tag_pointer);
+  id_len = id_len_serialized[0] << 8;
+  // unsigned char and uint16 get promoted to int.
+  id_len = static_cast<uint16>(id_len + id_len_serialized[1]);
+
+  int buffer_size_required = id_len + 1;
+  if (tag_buffer == NULL) {
+    *tag_buffer_len = buffer_size_required;
+    return true;
+  }
+  if (*tag_buffer_len < buffer_size_required) {
+    return false;
+  }
+  tag_pointer += sizeof(id_len);
+  memcpy(tag_buffer, tag_pointer, id_len);
+  tag_buffer[id_len] = '\0';
+  return true;
+}
+
+const void* TagExtractor::GetCertificateDirectoryPointer(
+    const void* base) const {
+  const char* image_base = reinterpret_cast<const char*>(base);
+
+  // Is this a PEF?
+  const IMAGE_DOS_HEADER* dos_header =
+    reinterpret_cast<const IMAGE_DOS_HEADER *>(image_base);
+  if (dos_header->e_magic != IMAGE_DOS_SIGNATURE) {
+    return NULL;
+  }
+
+  // Get PE header.
+  const IMAGE_NT_HEADERS* nt_headers = reinterpret_cast<const IMAGE_NT_HEADERS*>
+      (image_base + dos_header->e_lfanew);
+
+  // Again, is this a PEF? This code should get an F for not being endian-
+  // safe, but it gets an A for working in the real world.
+  if (nt_headers->Signature != IMAGE_NT_SIGNATURE) {
+    return NULL;
+  }
+
+  const IMAGE_DATA_DIRECTORY* idd =
+    reinterpret_cast<const IMAGE_DATA_DIRECTORY *>
+    (&nt_headers->
+    OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_SECURITY]);
+  if (idd->VirtualAddress != NULL) {
+    return image_base + idd->VirtualAddress;
+  }
+  return NULL;
+}
+
+const void* TagExtractor::GetASN1SignaturePointer(const void* base) const {
+  const WIN_CERTIFICATE* cert =
+    reinterpret_cast<const WIN_CERTIFICATE *>(base);
+  return cert->bCertificate;
+}
+
+int TagExtractor::GetASN1SignatureLength(const void* base) const {
+  const unsigned char* sig_base =
+    reinterpret_cast<const unsigned char*>(base);
+
+  // No, this isn't a full ASN.1 parser. We're just doing the very bare
+  // minimum to extract a length.
+  if (*sig_base++ == 0x30 && *sig_base++ == 0x82) {
+    int len = (*sig_base++ << 8);
+    len += *sig_base++;
+    // Windows pads the certificate directory to align at a 8-byte boundary.
+    // This piece of code it trying to replicate the logic that is used to
+    // calculate the padding to be added to the certificate. It returns
+    // the entire length of the certificate directory from the windows
+    // certificate directory start to the end of padding.
+    // The windows certificate directory has the following structure
+    // <WIN_CERTIFICATE><Certificate><Padding>.
+    // WIN_CERTIFICATE is the windows certificate directory structure.
+    // <Certificate> has the following format:
+    // <Magic(2 bytes)><Cert length(2 bytes)><Certificate Data>
+    // Note that the "Cert length" does not include the magic bytes or
+    // the length.
+    //
+    // Hence the total length of the certificate is:
+    // cert_length + "WIN_CERTIFICATE header size" + magic + length
+    // + padding = (cert length + 8 + 2 + 2 + 7) & (0-8)
+    return (len + 8 + 2 + 2 + 7) & 0xffffff8;
+  }
+  return 0;
+}
+
+}  // namespace omaha
+