Split payload application code into a subdirectory.

This patch splits from the main libupdate_engine code the part that
is strictly used to download and apply a payload into a new static
library, moving the code to subdirectories. The new library is divided
in two subdirectories: common/ and payload_consumer/, and should not
depend on other update_engine files outside those two subdirectories.
The main difference between those two is that the common/ tools are more
generic and not tied to the payload consumer process, but otherwise they
are both compiled together.

There are still dependencies from the new libpayload_consumer library
into the main directory files and DBus generated files. Those will be
addressed in follow up CLs.

Bug: 25197634
Test: FEATURES=test emerge-link update_engine; `mm` on Brillo.

Change-Id: Id8d0204ea573627e6e26ca9ea17b9592ca95bc23
diff --git a/common/hash_calculator_unittest.cc b/common/hash_calculator_unittest.cc
new file mode 100644
index 0000000..27dbc56
--- /dev/null
+++ b/common/hash_calculator_unittest.cc
@@ -0,0 +1,174 @@
+//
+// Copyright (C) 2009 The Android Open Source Project
+//
+// 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 "update_engine/common/hash_calculator.h"
+
+#include <math.h>
+#include <unistd.h>
+
+#include <string>
+#include <vector>
+
+#include <brillo/secure_blob.h>
+#include <gtest/gtest.h>
+
+#include "update_engine/common/libcurl_http_fetcher.h"
+#include "update_engine/common/utils.h"
+
+using std::string;
+using std::vector;
+
+namespace chromeos_update_engine {
+
+// Generated by running this on a linux shell:
+// $ echo -n hi | openssl dgst -sha256 -binary | openssl base64
+static const char kExpectedHash[] =
+    "j0NDRmSPa5bfid2pAcUXaxCm2Dlh3TwayItZstwyeqQ=";
+static const uint8_t kExpectedRawHash[] = {
+  0x8f, 0x43, 0x43, 0x46, 0x64, 0x8f, 0x6b, 0x96,
+  0xdf, 0x89, 0xdd, 0xa9, 0x01, 0xc5, 0x17, 0x6b,
+  0x10, 0xa6, 0xd8, 0x39, 0x61, 0xdd, 0x3c, 0x1a,
+  0xc8, 0x8b, 0x59, 0xb2, 0xdc, 0x32, 0x7a, 0xa4
+};
+
+class HashCalculatorTest : public ::testing::Test {
+ public:
+  HashCalculatorTest() {}
+};
+
+TEST_F(HashCalculatorTest, SimpleTest) {
+  HashCalculator calc;
+  calc.Update("hi", 2);
+  calc.Finalize();
+  EXPECT_EQ(kExpectedHash, calc.hash());
+  brillo::Blob raw_hash(std::begin(kExpectedRawHash),
+                        std::end(kExpectedRawHash));
+  EXPECT_TRUE(raw_hash == calc.raw_hash());
+}
+
+TEST_F(HashCalculatorTest, MultiUpdateTest) {
+  HashCalculator calc;
+  calc.Update("h", 1);
+  calc.Update("i", 1);
+  calc.Finalize();
+  EXPECT_EQ(kExpectedHash, calc.hash());
+  brillo::Blob raw_hash(std::begin(kExpectedRawHash),
+                        std::end(kExpectedRawHash));
+  EXPECT_TRUE(raw_hash == calc.raw_hash());
+}
+
+TEST_F(HashCalculatorTest, ContextTest) {
+  HashCalculator calc;
+  calc.Update("h", 1);
+  string calc_context = calc.GetContext();
+  calc.Finalize();
+  HashCalculator calc_next;
+  calc_next.SetContext(calc_context);
+  calc_next.Update("i", 1);
+  calc_next.Finalize();
+  EXPECT_EQ(kExpectedHash, calc_next.hash());
+  brillo::Blob raw_hash(std::begin(kExpectedRawHash),
+                        std::end(kExpectedRawHash));
+  EXPECT_TRUE(raw_hash == calc_next.raw_hash());
+}
+
+TEST_F(HashCalculatorTest, BigTest) {
+  HashCalculator calc;
+
+  int digit_count = 1;
+  int next_overflow = 10;
+  for (int i = 0; i < 1000000; i++) {
+    char buf[8];
+    if (i == next_overflow) {
+      next_overflow *= 10;
+      digit_count++;
+    }
+    ASSERT_EQ(digit_count, snprintf(buf, sizeof(buf), "%d", i)) << " i = " << i;
+    calc.Update(buf, strlen(buf));
+  }
+  calc.Finalize();
+
+  // Hash constant generated by running this on a linux shell:
+  // $ C=0
+  // $ while [ $C -lt 1000000 ]; do
+  //     echo -n $C
+  //     let C=C+1
+  //   done | openssl dgst -sha256 -binary | openssl base64
+  EXPECT_EQ("NZf8k6SPBkYMvhaX8YgzuMgbkLP1XZ+neM8K5wcSsf8=", calc.hash());
+}
+
+TEST_F(HashCalculatorTest, UpdateFileSimpleTest) {
+  string data_path;
+  ASSERT_TRUE(
+      utils::MakeTempFile("data.XXXXXX", &data_path, nullptr));
+  ScopedPathUnlinker data_path_unlinker(data_path);
+  ASSERT_TRUE(utils::WriteFile(data_path.c_str(), "hi", 2));
+
+  static const int kLengths[] = { -1, 2, 10 };
+  for (size_t i = 0; i < arraysize(kLengths); i++) {
+    HashCalculator calc;
+    EXPECT_EQ(2, calc.UpdateFile(data_path, kLengths[i]));
+    EXPECT_TRUE(calc.Finalize());
+    EXPECT_EQ(kExpectedHash, calc.hash());
+    brillo::Blob raw_hash(std::begin(kExpectedRawHash),
+                          std::end(kExpectedRawHash));
+    EXPECT_TRUE(raw_hash == calc.raw_hash());
+  }
+
+  HashCalculator calc;
+  EXPECT_EQ(0, calc.UpdateFile(data_path, 0));
+  EXPECT_EQ(1, calc.UpdateFile(data_path, 1));
+  EXPECT_TRUE(calc.Finalize());
+  // echo -n h | openssl dgst -sha256 -binary | openssl base64
+  EXPECT_EQ("qqlAJmTxpB9A67xSyZk+tmrrNmYClY/fqig7ceZNsSM=", calc.hash());
+}
+
+TEST_F(HashCalculatorTest, RawHashOfFileSimpleTest) {
+  string data_path;
+  ASSERT_TRUE(
+      utils::MakeTempFile("data.XXXXXX", &data_path, nullptr));
+  ScopedPathUnlinker data_path_unlinker(data_path);
+  ASSERT_TRUE(utils::WriteFile(data_path.c_str(), "hi", 2));
+
+  static const int kLengths[] = { -1, 2, 10 };
+  for (size_t i = 0; i < arraysize(kLengths); i++) {
+    brillo::Blob exp_raw_hash(std::begin(kExpectedRawHash),
+                              std::end(kExpectedRawHash));
+    brillo::Blob raw_hash;
+    EXPECT_EQ(2, HashCalculator::RawHashOfFile(data_path,
+                                               kLengths[i],
+                                               &raw_hash));
+    EXPECT_TRUE(exp_raw_hash == raw_hash);
+  }
+}
+
+TEST_F(HashCalculatorTest, UpdateFileNonexistentTest) {
+  HashCalculator calc;
+  EXPECT_EQ(-1, calc.UpdateFile("/some/non-existent/file", -1));
+}
+
+TEST_F(HashCalculatorTest, AbortTest) {
+  // Just make sure we don't crash and valgrind doesn't detect memory leaks
+  {
+    HashCalculator calc;
+  }
+  {
+    HashCalculator calc;
+    calc.Update("h", 1);
+  }
+}
+
+}  // namespace chromeos_update_engine