8 files changed, 273 insertions, 0 deletions
diff --git a/install_attributes/libinstallattributes.cc b/install_attributes/libinstallattributes.cc
new file mode 100644
index 0000000..52f9f70
--- /dev/null
+++ b/install_attributes/libinstallattributes.cc
@@ -0,0 +1,82 @@
+// Copyright 2016 The Chromium OS 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 "libinstallattributes.h"
+
+#include <base/files/file_util.h>
+#include <base/logging.h>
+
+#include "bindings/install_attributes.pb.h"
+
+namespace {
+
+// Written by cryptohome or by lockbox-cache after signature verification and
+// thus guaranteed to be unadulterated.
+const char kInstallAttributesPath[] = "/run/lockbox/install_attributes.pb";
+
+}  // namespace
+
+// The source of truth for these constants is Chromium
+// //chrome/browser/chromeos/settings/install_attributes.cc.
+const char InstallAttributesReader::kAttrMode[] = "enterprise.mode";
+const char InstallAttributesReader::kDeviceModeConsumer[] = "consumer";
+const char InstallAttributesReader::kDeviceModeEnterprise[] = "enterprise";
+const char InstallAttributesReader::kDeviceModeEnterpriseAD[] = "enterprise_ad";
+const char InstallAttributesReader::kDeviceModeLegacyRetail[] = "kiosk";
+const char InstallAttributesReader::kDeviceModeConsumerKiosk[] =
+    "consumer_kiosk";
+
+InstallAttributesReader::InstallAttributesReader()
+    : install_attributes_path_(kInstallAttributesPath) {
+}
+
+InstallAttributesReader::~InstallAttributesReader() {
+}
+
+const std::string& InstallAttributesReader::GetAttribute(
+    const std::string& key) {
+  // By its very nature of immutable attributes, once read successfully the
+  // attributes can never change and thus never need reloading.
+  if (!initialized_) {
+    TryToLoad();
+  }
+
+  const auto entry = attributes_.find(key);
+  if (entry == attributes_.end()) {
+    return empty_string_;
+  }
+  return entry->second;
+}
+
+bool InstallAttributesReader::IsLocked() {
+  if (!initialized_) {
+    TryToLoad();
+  }
+  return initialized_;
+}
+
+void InstallAttributesReader::TryToLoad() {
+  std::string contents;
+  if (!base::ReadFileToString(install_attributes_path_, &contents)) {
+    // May fail during OOBE or early in the boot process.
+    return;
+  }
+
+  // Parse errors are unrecoverable (lockbox does atomic write), thus mark as
+  // inititialized already before checking for parse errors.
+  initialized_ = true;
+
+  cryptohome::SerializedInstallAttributes install_attributes;
+  if (!install_attributes.ParseFromString(contents)) {
+    LOG(ERROR) << "Can't parse install attributes.";
+    return;
+  }
+
+  for (int i = 0; i < install_attributes.attributes_size(); ++i) {
+    const cryptohome::SerializedInstallAttributes_Attribute& attribute =
+        install_attributes.attributes(i);
+    // Cast value to C string and back to remove trailing zero.
+    attributes_[attribute.name()] = std::string(attribute.value().c_str());
+  }
+}
diff --git a/install_attributes/libinstallattributes.h b/install_attributes/libinstallattributes.h
new file mode 100644
index 0000000..b947156
--- /dev/null
+++ b/install_attributes/libinstallattributes.h
@@ -0,0 +1,66 @@
+// Copyright 2016 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef LIBBRILLO_INSTALL_ATTRIBUTES_LIBINSTALLATTRIBUTES_H_
+#define LIBBRILLO_INSTALL_ATTRIBUTES_LIBINSTALLATTRIBUTES_H_
+
+#include <map>
+#include <string>
+
+#include <base/files/file_path.h>
+#include <brillo/brillo_export.h>
+
+// Simple caching reader for the (verified) install attributes, a TPM-backed
+// write once read many store.  Install attributes may be written exactly once
+// by a single, atomic write-and-lock operation encompassing zero or more
+// attributes.  Once locked, install attributes cannot be re-written unless TPM
+// is reset (eg. by powerwashing the device).
+class BRILLO_EXPORT InstallAttributesReader {
+ public:
+  static const char kAttrMode[];
+
+  // Constants for the possible device modes.
+  static const char kDeviceModeConsumer[];
+  static const char kDeviceModeEnterprise[];
+  static const char kDeviceModeEnterpriseAD[];
+  static const char kDeviceModeLegacyRetail[];
+  static const char kDeviceModeConsumerKiosk[];
+
+  InstallAttributesReader();
+  virtual ~InstallAttributesReader();
+
+  // Try to load install attributes (unless cached already) and return the
+  // attribute for |key| or an empty string in case |key| doesn't exist or in
+  // case install attributes couldn't (yet) be loaded.  The latter is expected
+  // during OOBE (install attributes haven't yet been finalized) or early in the
+  // boot sequence (install attributes haven't yet been verified).
+  const std::string& GetAttribute(const std::string& key);
+
+  // Try to load install attributes (unless cached already) and return whether
+  // they have yet been written-and-locked.
+  bool IsLocked();
+
+ protected:
+  // Attributes cache.
+  std::map<std::string, std::string> attributes_;
+
+  // Path to the *verified* install attributes file on disk.
+  base::FilePath install_attributes_path_;
+
+  // Whether install attributes have been read successfully.  Reading a file
+  // containing an empty attributes proto indicates consumer mode and counts as
+  // successful, too.
+  bool initialized_ = false;
+
+private:
+  // Try to load the verified install attributes from disk.  This is expected to
+  // fail when install attributes haven't yet been finalized (OOBE) or verified
+  // (early in the boot sequence).
+  void TryToLoad();
+
+  // Empty string to return on error.
+  std::string empty_string_;
+};
+
+#endif  // LIBBRILLO_LIBINSTALLATTRIBUTES_H_
diff --git a/install_attributes/mock_install_attributes_reader.cc b/install_attributes/mock_install_attributes_reader.cc
new file mode 100644
index 0000000..da18988
--- /dev/null
+++ b/install_attributes/mock_install_attributes_reader.cc
@@ -0,0 +1,22 @@
+// Copyright 2016 The Chromium OS 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 "mock_install_attributes_reader.h"
+
+MockInstallAttributesReader::MockInstallAttributesReader(
+    const cryptohome::SerializedInstallAttributes& install_attributes) {
+  for (int i = 0; i < install_attributes.attributes_size(); ++i) {
+    const cryptohome::SerializedInstallAttributes_Attribute& attribute =
+        install_attributes.attributes(i);
+    // Cast value to C string and back to remove trailing zero.
+    attributes_[attribute.name()] = std::string(attribute.value().c_str());
+  }
+  initialized_ = true;
+}
+
+MockInstallAttributesReader::MockInstallAttributesReader(
+    const std::string& device_mode, bool initialized) {
+  attributes_[kAttrMode] = device_mode;
+  initialized_ = initialized;
+}
diff --git a/install_attributes/mock_install_attributes_reader.h b/install_attributes/mock_install_attributes_reader.h
new file mode 100644
index 0000000..5ccee02
--- /dev/null
+++ b/install_attributes/mock_install_attributes_reader.h
@@ -0,0 +1,19 @@
+// Copyright 2016 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef LIBBRILLO_INSTALL_ATTRIBUTES_MOCK_INSTALL_ATTRIBUTES_READER_H_
+#define LIBBRILLO_INSTALL_ATTRIBUTES_MOCK_INSTALL_ATTRIBUTES_READER_H_
+
+#include "libinstallattributes.h"
+
+#include "bindings/install_attributes.pb.h"
+
+class MockInstallAttributesReader : public InstallAttributesReader {
+ public:
+  explicit MockInstallAttributesReader(
+      const cryptohome::SerializedInstallAttributes& install_attributes);
+  MockInstallAttributesReader(const std::string& device_mode, bool initialized);
+};
+
+#endif  // LIBBRILLO_INSTALL_ATTRIBUTES_MOCK_INSTALL_ATTRIBUTES_READER_H_
diff --git a/install_attributes/tests/consumer.pb b/install_attributes/tests/consumer.pb
new file mode 100644
index 0000000..e19a122
--- /dev/null
+++ b/install_attributes/tests/consumer.pb
@@ -0,0 +1 @@
+
+\ No newline at end of file
diff --git a/install_attributes/tests/corrupt.pb b/install_attributes/tests/corrupt.pb
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/install_attributes/tests/corrupt.pb
diff --git a/install_attributes/tests/libinstallattributes_unittest.cc b/install_attributes/tests/libinstallattributes_unittest.cc
new file mode 100644
index 0000000..45ff827
--- /dev/null
+++ b/install_attributes/tests/libinstallattributes_unittest.cc
@@ -0,0 +1,83 @@
+// Copyright (c) 2012 The Chromium OS 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 "install_attributes/libinstallattributes.h"
+
+#include <string>
+
+#include <gtest/gtest.h>
+
+// Allows to override the install attributes path while preserving all the
+// functionality of the original class.
+class MockInstallAttributesReader : public InstallAttributesReader {
+ public:
+  void SetPath(const std::string& filename) {
+    install_attributes_path_ = base::FilePath(filename);
+  }
+  size_t GetAttributesCount() const { return attributes_.size(); }
+};
+
+TEST(InstallAttributesTest, ReadNonexistingAttributes) {
+  MockInstallAttributesReader reader;
+  reader.SetPath("non-existing.pb");
+  ASSERT_FALSE(reader.IsLocked());
+  ASSERT_EQ(0, reader.GetAttributesCount());
+}
+
+// corrupt.pb is an invalid proto.
+TEST(InstallAttributesTest, ReadCorruptAttributes) {
+  MockInstallAttributesReader reader;
+  reader.SetPath("install_attributes/tests/corrupt.pb");
+  ASSERT_TRUE(reader.IsLocked());
+  ASSERT_EQ(0, reader.GetAttributesCount());
+}
+
+// consumer.pb is a valid proto containing no attributes.
+TEST(InstallAttributesTest, ReadEmptyAttributes) {
+  MockInstallAttributesReader reader;
+  reader.SetPath("install_attributes/tests/consumer.pb");
+  ASSERT_TRUE(reader.IsLocked());
+  ASSERT_EQ(0, reader.GetAttributesCount());
+}
+
+// managed.pb is a valid proto containing the usual enterprise enrollment
+// attributes.
+TEST(InstallAttributesTest, ReadManagedAttributes) {
+  MockInstallAttributesReader reader;
+  reader.SetPath("install_attributes/tests/managed.pb");
+  ASSERT_TRUE(reader.IsLocked());
+  ASSERT_EQ(std::string(), reader.GetAttribute("non-existing"));
+  ASSERT_EQ("enterprise", reader.GetAttribute("enterprise.mode"));
+}
+
+// Going from non-existing attributes file to existing attributes file must
+// work, i.e. the non-existence of the attributes file must not be cached.
+TEST(InstallAttributesTest, ProgressionFromNonExistingToManaged) {
+  MockInstallAttributesReader reader;
+  reader.SetPath("non-existing.pb");
+  ASSERT_FALSE(reader.IsLocked());
+  ASSERT_EQ(0, reader.GetAttributesCount());
+
+  reader.SetPath("install_attributes/tests/managed.pb");
+  ASSERT_TRUE(reader.IsLocked());
+  ASSERT_EQ("enterprise", reader.GetAttribute("enterprise.mode"));
+}
+
+// Going from empty attributes file to non-empty attributes file must not work,
+// i.e. the non-existence of the attributes must be cached.
+TEST(InstallAttributesTest, NoProgressionFromEmptyToManaged) {
+  MockInstallAttributesReader reader;
+  reader.SetPath("install_attributes/tests/consumer.pb");
+  ASSERT_TRUE(reader.IsLocked());
+  ASSERT_EQ(0, reader.GetAttributesCount());
+
+  reader.SetPath("install_attributes/tests/managed.pb");
+  ASSERT_TRUE(reader.IsLocked());
+  ASSERT_EQ(std::string(), reader.GetAttribute("enterprise.mode"));
+}
+
+int main(int argc, char* argv[]) {
+  ::testing::InitGoogleTest(&argc, argv);
+  return RUN_ALL_TESTS();
+}
diff --git a/install_attributes/tests/managed.pb b/install_attributes/tests/managed.pb
new file mode 100644
index 0000000..4060a49
--- /dev/null
+++ b/install_attributes/tests/managed.pb