Modelled on base/base64url.h.
Modifies chrome/installer/util/shell_util to use this component.
It will soon be used by components/certificate_transparency as well.

Discussion:
https://groups.google.com/a/chromium.org/forum/?pli=1#!topic/chromium-dev/pieHLJZZE7k

BUG=612439

Review-Url: https://codereview.chromium.org/2017123002
Cr-Commit-Position: refs/heads/master@{#398539}
diff --git a/components/base32/base32_unittest.cc b/components/base32/base32_unittest.cc
new file mode 100644
index 0000000..350b61c
--- /dev/null
+++ b/components/base32/base32_unittest.cc
@@ -0,0 +1,55 @@
+// Copyright 2016 The Chromium 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 <string>
+
+#include "components/base32/base32.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace base32 {
+namespace {
+
+TEST(Base32Test, EncodesRfcTestVectorsCorrectlyWithoutPadding) {
+  // Tests from http://tools.ietf.org/html/rfc4648#section-10.
+  constexpr char test_str[] = "foobar";
+
+  constexpr const char* expected[] = {
+      "", "MY", "MZXQ", "MZXW6", "MZXW6YQ", "MZXW6YTB", "MZXW6YTBOI"};
+
+  // Run the tests, with one more letter in the input every pass.
+  for (size_t i = 0; i < arraysize(expected); ++i) {
+    std::string output = Base32Encode(base::StringPiece(test_str, i),
+                                      Base32EncodePolicy::OMIT_PADDING);
+    EXPECT_EQ(expected[i], output);
+  }
+}
+
+TEST(Base32Test, EncodesRfcTestVectorsCorrectlyWithPadding) {
+  // Tests from http://tools.ietf.org/html/rfc4648#section-10.
+  constexpr char test_str[] = "foobar";
+
+  constexpr const char* expected[] = {
+      "",         "MY======", "MZXQ====",        "MZXW6===",
+      "MZXW6YQ=", "MZXW6YTB", "MZXW6YTBOI======"};
+
+  // Run the tests, with one more letter in the input every pass.
+  for (size_t i = 0; i < arraysize(expected); ++i) {
+    std::string output = Base32Encode(base::StringPiece(test_str, i));
+    EXPECT_EQ(expected[i], output);
+  }
+}
+
+TEST(Base32Test, EncodesSha256HashCorrectly) {
+  // Useful to test with longer input than the RFC test vectors, and encoding
+  // SHA-256 hashes is one of the use cases for this component.
+  constexpr char hash[] =
+      "\x1f\x25\xe1\xca\xba\x4f\xf9\xb8\x27\x24\x83\x0f\xca\x60\xe4\xc2\xbe\xa8"
+      "\xc3\xa9\x44\x1c\x27\xb0\xb4\x3e\x6a\x96\x94\xc7\xb8\x04";
+  std::string output = Base32Encode(base::StringPiece(hash, 32),
+                                    Base32EncodePolicy::OMIT_PADDING);
+  EXPECT_EQ("D4S6DSV2J743QJZEQMH4UYHEYK7KRQ5JIQOCPMFUHZVJNFGHXACA", output);
+}
+
+}  // namespace
+}  // namespace base32