Bring in adb key generation library from emu-master-dev

This brings in a set of functions to manipulate adb public and private
keys.

Test: All unit tests are green
Change-Id: Ifdbaf7428e4f428ed36e50ede0d79e713dcb2aeb

4 files changed, 675 insertions, 0 deletions

diff --git a/adb/secrets/BUILD.bazel b/adb/secrets/BUILD.bazel
new file mode 100644
index 0000000..86100c1
--- /dev/null
+++ b/adb/secrets/BUILD.bazel
@@ -0,0 +1,39 @@
+cc_library(
+    name = "secrets",
+    srcs = glob([
+        "src/**/*.cpp",
+    ]),
+    hdrs = glob([
+        "include/**/*.h",
+    ]),
+    includes = [
+        "include",
+        "src",
+    ],
+    visibility = ["//visibility:public"],
+    deps = [
+        "//external/boringssl:ssl",
+        "//hardware/generic/goldfish/android/files",
+        "//hardware/generic/goldfish/files",
+        "//hardware/generic/goldfish/system",
+        "//hardware/google/aemu/base:aemu-base",
+        "@com_google_absl//absl/strings",
+        "@com_google_absl//absl/strings:str_format",
+    ],
+)
+
+cc_test(
+    name = "secrets_unnitests",
+    srcs = glob(
+        [
+            "test/**/*.cpp",
+            "test/**/*.h",
+        ],
+        exclude = ["test/**/Win32"],
+    ),
+    deps = [
+        ":secrets",
+        "//hardware/generic/goldfish/system:test-headers",
+        "@com_google_googletest//:gtest_main",
+    ],
+)
diff --git a/adb/secrets/include/android/emulation/control/adb/adbkey.h b/adb/secrets/include/android/emulation/control/adb/adbkey.h
new file mode 100644
index 0000000..c5a2e4a
--- /dev/null
+++ b/adb/secrets/include/android/emulation/control/adb/adbkey.h
@@ -0,0 +1,58 @@
+// Copyright 2019 The Android Open Source Project
+//
+// This software is licensed under the terms of the GNU General Public
+// License version 2, as published by the Free Software Foundation, and
+// may be copied, distributed, and modified under those terms.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+#pragma once
+
+#include <cstdint>
+#include <filesystem>
+#include <openssl/rsa.h>
+#include <string>
+
+// Size of an RSA modulus such as an encrypted block or a signature.
+constexpr const int ANDROID_PUBKEY_MODULUS_SIZE = 2048 / 8;
+// Adb authentication
+constexpr const int TOKEN_SIZE = 20;
+
+// Size of an encoded RSA key.
+constexpr const int ANDROID_PUBKEY_ENCODED_SIZE =
+    (3 * sizeof(uint32_t) + 2 * ANDROID_PUBKEY_MODULUS_SIZE);
+constexpr const char *kPrivateKeyFileName = "adbkey";
+constexpr const char *kPublicKeyFileName = "adbkey.pub";
+
+// Tries to find |adbKeyFileName|, returning "" if not found.
+// Will search the default key directories.
+std::filesystem::path
+getAdbKeyPath(const std::filesystem::path &adbKeyFileName);
+
+// Tries to find the "adbkey.pub" file, returning "" if not found
+std::filesystem::path getPublicAdbKeyPath();
+
+// Tries to find the "adbkey" file, returning "" if not found
+std::filesystem::path getPrivateAdbKeyPath();
+
+bool adb_auth_keygen(const std::filesystem::path &filename);
+
+// Creates a public key given the private key.
+// |path| Path to the adb private key.
+// |out| string receiving the public key.
+bool pubkey_from_privkey(const std::filesystem::path &path, std::string *out);
+
+/* Encodes |key| in the Android RSA public key binary format and stores the
+ * bytes in |key_buffer|. |key_buffer| should be of size at least
+ * |ANDROID_PUBKEY_ENCODED_SIZE|.
+ *
+ * Returns true if successful, false on error.
+ */
+bool android_pubkey_encode(const RSA *key, uint8_t *key_buffer, size_t size);
+bool android_pubkey_decode(const uint8_t *key_buffer, size_t size, RSA **key);
+bool sign_auth_token(const uint8_t *token, int token_size, uint8_t *sig,
+                     int &siglen);
+bool calculate_public_key(std::string *out, RSA *private_key);
diff --git a/adb/secrets/src/android/emulation/control/adb/adbkey.cpp b/adb/secrets/src/android/emulation/control/adb/adbkey.cpp
new file mode 100644
index 0000000..2f0f1ff
--- /dev/null
+++ b/adb/secrets/src/android/emulation/control/adb/adbkey.cpp
@@ -0,0 +1,347 @@
+// Copyright 2019 The Android Open Source Project
+//
+// This software is licensed under the terms of the GNU General Public
+// License version 2, as published by the Free Software Foundation, and
+// may be copied, distributed, and modified under those terms.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+#include "android/emulation/control/adb/adbkey.h"
+
+#include <openssl/base.h>
+#include <openssl/base64.h> // for EVP_EncodeBlock, EVP_Encod...
+#include <openssl/bn.h>
+#include <openssl/evp.h>
+#include <openssl/nid.h>
+#include <openssl/pem.h>
+#include <openssl/rsa.h>
+
+#include <cstdio>
+#include <filesystem>
+#include <memory>
+#include <string.h>
+#include <string>
+#include <sys/types.h>
+#include <vector>
+
+#include "aemu/base/Log.h"
+#include "aemu/base/files/PathUtils.h"
+#include "android/base/file/file_io.h"
+#include "android/base/system/System.h"
+#include "android/goldfish/ConfigDirs.h"
+#include "android/utils/path.h"
+
+namespace fs = std::filesystem;
+/* set >0 for very verbose debugging */
+#define DEBUG 0
+
+#define D(...) (void)0
+#define DD(...) (void)0
+#if DEBUG >= 1
+#undef D
+#define D(fmt, ...)                                                            \
+  fprintf(stderr, "adbkey: %s:%d| " fmt "\n", __func__, __LINE__, ##__VA_ARGS__)
+#endif
+#if DEBUG >= 2
+#undef DD
+#define DD(fmt, ...)                                                           \
+  fprintf(stderr, "adbkey: %s:%d| " fmt "\n", __func__, __LINE__, ##__VA_ARGS__)
+#endif
+
+using android::base::System;
+
+// Better safe than sorry.
+static_assert(ANDROID_PUBKEY_MODULUS_SIZE % 4 == 0,
+              "RSA modulus size must be multiple of the word size!");
+
+// Size of the RSA modulus in words.
+constexpr const int ANDROID_PUBKEY_MODULUS_SIZE_WORDS =
+    ANDROID_PUBKEY_MODULUS_SIZE / 4;
+
+namespace {
+std::string get_user_info() {
+  std::string hostname = System::get()->getEnvironmentVariable("HOSTNAME");
+  if (hostname.empty()) {
+    hostname = "unknown";
+  }
+
+  std::string username;
+  if (getenv("LOGNAME")) {
+    username = getenv("LOGNAME");
+  }
+  if (username.empty()) {
+    hostname = "unknown";
+  }
+  return " " + username + "@" + hostname;
+}
+
+} // namespace
+
+// From ${AOSP}/system/core/adb/client/auth.cpp
+bool calculate_public_key(std::string *out, RSA *private_key) {
+  uint8_t binary_key_data[ANDROID_PUBKEY_ENCODED_SIZE];
+  if (!android_pubkey_encode(private_key, binary_key_data,
+                             sizeof(binary_key_data))) {
+    LOG(ERROR) << "Failed to convert to public key";
+    return false;
+  }
+
+  size_t expected_length;
+  if (!EVP_EncodedLength(&expected_length, sizeof(binary_key_data))) {
+    LOG(ERROR) << "Public key too large to base64 encode";
+    return false;
+  }
+
+  out->resize(expected_length);
+  size_t actual_length = EVP_EncodeBlock(
+      (uint8_t *)out->data(), binary_key_data, sizeof(binary_key_data));
+  out->resize(actual_length);
+  out->append(get_user_info());
+  return true;
+}
+
+static std::shared_ptr<RSA> read_key_file(const std::string &file) {
+  std::unique_ptr<FILE, decltype(&fclose)> fp(android_fopen(file.c_str(), "r"),
+                                              fclose);
+  if (!fp) {
+    LOG(ERROR) << "Failed to open rsa file: " << file;
+    return nullptr;
+  }
+
+  RSA *key = RSA_new();
+  if (!PEM_read_RSAPrivateKey(fp.get(), &key, nullptr, nullptr)) {
+    LOG(ERROR) << "Failed to read rsa key";
+    RSA_free(key);
+    return nullptr;
+  }
+
+  return std::shared_ptr<RSA>(key, RSA_free);
+}
+
+static bool generate_key(const std::string &file) {
+
+  mode_t old_mask;
+  FILE *f = nullptr;
+  bool ret = false;
+
+  EVP_PKEY *pkey = EVP_PKEY_new();
+  BIGNUM *exponent = BN_new();
+  RSA *rsa = RSA_new();
+  if (!pkey || !exponent || !rsa) {
+    dwarning("Failed to allocate key");
+    goto out;
+  }
+
+  BN_set_word(exponent, RSA_F4);
+  RSA_generate_key_ex(rsa, 2048, exponent, nullptr);
+  EVP_PKEY_set1_RSA(pkey, rsa);
+
+  f = android_fopen(file.c_str(), "w");
+  if (!f) {
+    dwarning("Failed to open %s", file.c_str());
+    goto out;
+  }
+
+  if (!PEM_write_PrivateKey(f, pkey, nullptr, nullptr, 0, nullptr, nullptr)) {
+    dwarning("Failed to write key");
+    goto out;
+  }
+
+  fclose(f);
+  f = nullptr;
+  android_chmod(file.c_str(), 0777);
+
+  ret = true;
+
+out:
+  if (f) {
+    fclose(f);
+  }
+  EVP_PKEY_free(pkey);
+  RSA_free(rsa);
+  BN_free(exponent);
+  return ret;
+}
+
+bool adb_auth_keygen(const fs::path &filename) { return generate_key(filename); }
+
+bool pubkey_from_privkey(const fs::path &path, std::string *out) {
+  std::shared_ptr<RSA> privkey = read_key_file(path);
+  if (!privkey) {
+    return false;
+  }
+  return calculate_public_key(out, privkey.get());
+}
+
+// Get adbkey path, return "" if failed
+// adbKeyFileName could be "adbkey" or "adbkey.pub"
+fs::path getAdbKeyPath(const fs::path& adbKeyFileName) {
+  fs::path adbKeyPath = android::goldfish::ConfigDirs::getUserDirectory() / adbKeyFileName;
+  if (path_is_regular(adbKeyPath.c_str()) &&
+      path_can_read(adbKeyPath.c_str())) {
+    return adbKeyPath;
+  }
+  D("cannot read adb key file: %s", adbKeyPath.c_str());
+  D("trying again by copying from home dir");
+
+  auto home = System::get()->getHomeDirectory();
+  if (home.empty()) {
+    home = System::get()->getTempDir();
+    if (home.empty()) {
+      home = "/tmp";
+    }
+  }
+  D("Looking in %s", home.c_str());
+
+  auto guessedSrcAdbKeyPub = home / ".android" / adbKeyFileName;
+  path_copy_file(adbKeyPath.c_str(), guessedSrcAdbKeyPub.c_str());
+
+  if (path_is_regular(adbKeyPath.c_str()) &&
+      path_can_read(adbKeyPath.c_str())) {
+    return adbKeyPath;
+  }
+  D("cannot read adb key file (failed): %s", adbKeyPath.c_str());
+  return "";
+}
+
+fs::path getPublicAdbKeyPath() { return getAdbKeyPath(kPublicKeyFileName); }
+
+fs::path getPrivateAdbKeyPath() {
+  return getAdbKeyPath(kPrivateKeyFileName);
+}
+
+// This file implements encoding and decoding logic for Android's custom RSA
+// public key binary format. Public keys are stored as a sequence of
+// little-endian 32 bit words. Note that Android only supports little-endian
+// processors, so we don't do any byte order conversions when parsing the binary
+// struct.
+typedef struct RSAPublicKey {
+  // Modulus length. This must be ANDROID_PUBKEY_MODULUS_SIZE.
+  uint32_t modulus_size_words;
+
+  // Precomputed montgomery parameter: -1 / n[0] mod 2^32
+  uint32_t n0inv;
+
+  // RSA modulus as a little-endian array.
+  uint8_t modulus[ANDROID_PUBKEY_MODULUS_SIZE];
+
+  // Montgomery parameter R^2 as a little-endian array of little-endian words.
+  uint8_t rr[ANDROID_PUBKEY_MODULUS_SIZE];
+
+  // RSA modulus: 3 or 65537
+  uint32_t exponent;
+} RSAPublicKey;
+
+bool android_pubkey_decode(const uint8_t *key_buffer, size_t size, RSA **key) {
+  // Check |size| is large enough and the modulus size is correct.
+  if (size < sizeof(RSAPublicKey)) {
+    LOG(ERROR) << "WARNING: adbkey decode failed.";
+    return false;
+  }
+  RSAPublicKey key_struct;
+  memcpy(&key_struct, key_buffer, sizeof(key_struct));
+
+  if (key_struct.modulus_size_words != ANDROID_PUBKEY_MODULUS_SIZE_WORDS) {
+    LOG(ERROR) << "WARNING: adbkey decode failed.";
+    return false;
+  }
+
+  // Read the modulus and exponent.
+  bssl::UniquePtr<BIGNUM> n(
+      BN_le2bn(key_struct.modulus, ANDROID_PUBKEY_MODULUS_SIZE, nullptr));
+  bssl::UniquePtr<BIGNUM> e(BN_new());
+  if (!n || !e || !BN_set_word(e.get(), key_struct.exponent)) {
+    LOG(ERROR) << "WARNING: adbkey decode failed.";
+    return false;
+  }
+
+  // TODO(davidben): After we're sure the BoringSSL update has stuck, switch
+  // this to RSA_new_public_key, which is a bit less tedious. For now, use the
+  // older APIs to avoid a build break if it gets temporarily reverted.
+  bssl::UniquePtr<RSA> new_key(RSA_new());
+  if (!new_key ||
+      !RSA_set0_key(new_key.get(), n.get(), e.get(), /*d=*/nullptr)) {
+    LOG(ERROR) << "WARNING: adbkey decode failed.";
+    return false;
+  }
+  // RSA_set0_key takes ownership on success.
+  (void) n.release();
+  (void) e.release();
+
+  *key = new_key.release();
+  return true;
+}
+
+bool android_pubkey_encode(const RSA *key, uint8_t *key_buffer, size_t size) {
+  if (sizeof(RSAPublicKey) > size ||
+      RSA_size(key) != ANDROID_PUBKEY_MODULUS_SIZE) {
+    return false;
+  }
+
+  // Store the modulus size.
+  RSAPublicKey key_struct;
+  key_struct.modulus_size_words = ANDROID_PUBKEY_MODULUS_SIZE_WORDS;
+
+  // Compute and store n0inv = -1 / N[0] mod 2^32.
+  bssl::UniquePtr<BN_CTX> ctx(BN_CTX_new());
+  bssl::UniquePtr<BIGNUM> r32(BN_new());
+  bssl::UniquePtr<BIGNUM> n0inv(BN_new());
+  if (!ctx || !r32 || !n0inv || !BN_set_bit(r32.get(), 32) ||
+      !BN_mod(n0inv.get(), RSA_get0_n(key), r32.get(), ctx.get()) ||
+      !BN_mod_inverse(n0inv.get(), n0inv.get(), r32.get(), ctx.get()) ||
+      !BN_sub(n0inv.get(), r32.get(), n0inv.get())) {
+    return false;
+  }
+  key_struct.n0inv = (uint32_t)BN_get_word(n0inv.get());
+
+  // Store the modulus.
+  if (!BN_bn2le_padded(key_struct.modulus, ANDROID_PUBKEY_MODULUS_SIZE,
+                       RSA_get0_n(key))) {
+    return false;
+  }
+
+  // Compute and store rr = (2^(rsa_size)) ^ 2 mod N.
+  bssl::UniquePtr<BIGNUM> rr(BN_new());
+  if (!rr || !BN_set_bit(rr.get(), ANDROID_PUBKEY_MODULUS_SIZE * 8) ||
+      !BN_mod_sqr(rr.get(), rr.get(), RSA_get0_n(key), ctx.get()) ||
+      !BN_bn2le_padded(key_struct.rr, ANDROID_PUBKEY_MODULUS_SIZE, rr.get())) {
+    return false;
+  }
+
+  // Store the exponent.
+  key_struct.exponent = (uint32_t)BN_get_word(RSA_get0_e(key));
+  memcpy(key_buffer, &key_struct, sizeof(key_struct));
+  return true;
+}
+
+static bool sign_token(RSA *key_rsa, const uint8_t *token, int token_size,
+                       uint8_t *sig, int &len) {
+  if (token_size != TOKEN_SIZE) {
+    DD("Unexpected token size %d\n", token_size);
+  }
+
+  if (!RSA_sign(NID_sha1, token, (size_t)token_size, sig, (unsigned int *)&len,
+                key_rsa)) {
+    return false;
+  }
+
+  DD("successfully signed with siglen %d\n", (int)len);
+  return true;
+}
+
+bool sign_auth_token(const uint8_t *token, int token_size, uint8_t *sig,
+                     int &siglen) {
+  const std::string key_path = getAdbKeyPath(kPrivateKeyFileName);
+  if (key_path.empty()) {
+    LOG(ERROR) << "No private key found, unable to sign token";
+  }
+  auto rsa = read_key_file(key_path);
+  if (!rsa) {
+    LOG(ERROR) << "No RSA key available.";
+    return false;
+  }
+  return sign_token(rsa.get(), token, token_size, sig, siglen);
+}
diff --git a/adb/secrets/test/adbkey_unittest.cpp b/adb/secrets/test/adbkey_unittest.cpp
new file mode 100644
index 0000000..382eea7
--- /dev/null
+++ b/adb/secrets/test/adbkey_unittest.cpp
@@ -0,0 +1,231 @@
+// Copyright 2020 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 "android/emulation/control/adb/adbkey.h"
+#include <gtest/gtest.h>
+#include <openssl/obj_mac.h>
+#include <openssl/rsa.h>
+#include <memory>
+#include <fstream>
+#include <string>
+#include <vector>
+#include "android/base/testing/TestSystem.h"
+#include "android/base/testing/TestTempDir.h"
+
+namespace android {
+namespace base {
+
+// Secret token that gets verified.
+const uint8_t challenge_token[20] = {0xE8, 0x99, 0xE1, 0xFF, 0x95, 0x9B, 0x8F,
+                                     0x6B, 0x54, 0xBE, 0xCE, 0xC5, 0x42, 0xF1,
+                                     0x93, 0x7D, 0x3,  0x99, 0xA2, 0x32};
+
+// Private key that can be used to answer challenge token above.
+std::string privkey = R"##(-----BEGIN PRIVATE KEY-----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+-----END PRIVATE KEY-----)##";
+
+class AdbKeyTest : public ::testing::Test {
+public:
+    AdbKeyTest() {
+        mTestDir = mTestSystem.getTempRoot();
+        mTestDir->makeSubDir(".android");
+        mTestSystem.setHomeDirectory(mTestDir->path());
+    }
+
+    ~AdbKeyTest() {}
+
+protected:
+    TestSystem mTestSystem{"/"};
+    TestTempDir* mTestDir;
+    const char* tstKey = "adbsamplekey";
+};
+
+TEST_F(AdbKeyTest, key_does_not_exist) {
+    EXPECT_EQ("", getAdbKeyPath("thisshouldnotexist.boo"));
+}
+
+TEST_F(AdbKeyTest, find_keys_in_default_path) {
+    mTestDir->makeSubFile(".android/adbkey");
+    mTestDir->makeSubFile(".android/adbkey.pub");
+    EXPECT_NE("", getPrivateAdbKeyPath());
+    EXPECT_NE("", getPublicAdbKeyPath());
+}
+
+TEST_F(AdbKeyTest, generate_writes_a_key) {
+    std::string keyFile = mTestDir->path() / ".android" / tstKey;
+    EXPECT_EQ("", getAdbKeyPath(tstKey));
+    EXPECT_TRUE(adb_auth_keygen(keyFile.c_str()));
+    EXPECT_NE("", getAdbKeyPath(tstKey));
+}
+
+TEST_F(AdbKeyTest, can_create_pub_from_generated_priv) {
+    std::string pubkey;
+    std::string keyFile = mTestDir->path() / ".android" / tstKey;
+    EXPECT_TRUE(adb_auth_keygen(keyFile.c_str()));
+    EXPECT_TRUE(pubkey_from_privkey(keyFile, &pubkey));
+    EXPECT_NE("", pubkey);
+}
+
+TEST_F(AdbKeyTest, can_sign_token) {
+    std::string pubkey;
+    std::string keyFile = mTestDir->path() / ".android" / kPrivateKeyFileName;
+    std::ofstream out(keyFile);
+    out << privkey << std::endl;
+    out.close();
+
+
+    EXPECT_TRUE(pubkey_from_privkey(keyFile, &pubkey));
+    EXPECT_NE("", pubkey);
+
+    int siglen = 256;
+    std::vector<uint8_t> signed_token{};
+    signed_token.resize(siglen);
+    EXPECT_TRUE(sign_auth_token(challenge_token, sizeof(challenge_token),
+                                signed_token.data(), siglen));
+
+    EXPECT_NE("", std::string((char*)signed_token.data(), siglen));
+}
+
+// Test digest to verify.
+const uint8_t kDigest[] = {
+        0x31, 0x5f, 0x5b, 0xdb, 0x76, 0xd0, 0x78, 0xc4, 0x3b, 0x8a, 0xc0,
+        0x06, 0x4e, 0x4a, 0x01, 0x64, 0x61, 0x2b, 0x1f, 0xce, 0x77, 0xc8,
+        0x69, 0x34, 0x5b, 0xfc, 0x94, 0xc7, 0x58, 0x94, 0xed, 0xd3,
+};
+
+// 2048 RSA test key.
+const uint8_t kKey2048[ANDROID_PUBKEY_ENCODED_SIZE] = {
+        0x40, 0x00, 0x00, 0x00, 0x05, 0x75, 0x61, 0xd1, 0x33, 0xf0, 0x2d, 0x12,
+        0x45, 0xfb, 0xae, 0x07, 0x02, 0x15, 0x4f, 0x3a, 0x2b, 0xa3, 0xbc, 0x49,
+        0xbd, 0x14, 0x07, 0xa0, 0xc0, 0x9f, 0x0c, 0x52, 0x60, 0x77, 0x9f, 0xa2,
+        0x31, 0xd0, 0xa7, 0xfb, 0x7e, 0xde, 0xfb, 0xc9, 0x05, 0xc0, 0x97, 0xf7,
+        0x74, 0x99, 0xe6, 0xd1, 0x08, 0xa6, 0xc2, 0x59, 0x5a, 0xd8, 0x37, 0x1d,
+        0xe0, 0x48, 0x5e, 0x63, 0x44, 0x04, 0x8b, 0x05, 0x20, 0xf6, 0x25, 0x67,
+        0x38, 0xb2, 0xb6, 0xf9, 0xbe, 0xb6, 0x1d, 0x7f, 0x1b, 0x71, 0x8a, 0xeb,
+        0xb7, 0xf8, 0x01, 0xc1, 0x5e, 0xf7, 0xfe, 0x48, 0x08, 0x27, 0x0f, 0x27,
+        0x2a, 0x64, 0x1a, 0x43, 0x8d, 0xcf, 0x5a, 0x33, 0x5c, 0x18, 0xc5, 0xf4,
+        0xe7, 0xfe, 0xee, 0xd3, 0x12, 0x62, 0xad, 0x61, 0x78, 0x9a, 0x03, 0xb0,
+        0xaf, 0xab, 0x91, 0x57, 0x46, 0xbf, 0x18, 0xc6, 0xbc, 0x0c, 0x6b, 0x55,
+        0xcd, 0xda, 0xc4, 0xcc, 0x98, 0x46, 0x91, 0x99, 0xbc, 0xa3, 0xca, 0x6c,
+        0x86, 0xa6, 0x1c, 0x8f, 0xca, 0xf8, 0xf6, 0x8a, 0x00, 0x8e, 0x05, 0xd7,
+        0x13, 0x43, 0xe2, 0xf2, 0x1a, 0x13, 0xf3, 0x50, 0x13, 0xa4, 0xf2, 0x4e,
+        0x41, 0xb1, 0x36, 0x78, 0x55, 0x4c, 0x5e, 0x27, 0xc5, 0xc0, 0x4b, 0xd8,
+        0x93, 0xaa, 0x7e, 0xf0, 0x90, 0x08, 0x10, 0x26, 0x72, 0x6d, 0xb9, 0x21,
+        0xae, 0x4d, 0x01, 0x4b, 0x55, 0x1d, 0xe7, 0x1e, 0x5e, 0x31, 0x6e, 0x62,
+        0xd1, 0x33, 0x26, 0xcb, 0xdb, 0xfe, 0x72, 0x98, 0xc8, 0x06, 0x1c, 0x12,
+        0xdf, 0xfc, 0x74, 0xe5, 0x7a, 0x6f, 0xf5, 0xa3, 0x63, 0x08, 0xe3, 0x02,
+        0x68, 0x4d, 0x7c, 0x70, 0x05, 0xec, 0x95, 0x7e, 0x24, 0xa4, 0xbc, 0x4c,
+        0xcd, 0x39, 0x14, 0xb5, 0x2a, 0x8f, 0xc1, 0xe3, 0x4e, 0xfa, 0xf8, 0x70,
+        0x50, 0x8f, 0xd5, 0x8e, 0xc7, 0xb5, 0x32, 0x89, 0x4d, 0xbb, 0x6a, 0xc1,
+        0xc1, 0xa2, 0x42, 0x57, 0x57, 0xbd, 0x2a, 0xdc, 0xa6, 0xfd, 0xc8, 0x86,
+        0x44, 0x6a, 0x03, 0x5d, 0x4d, 0x28, 0xe1, 0xde, 0xb4, 0xa9, 0xa5, 0x03,
+        0x61, 0x7a, 0x5f, 0xb1, 0x09, 0x17, 0x2b, 0x9c, 0xa2, 0x54, 0x28, 0xad,
+        0x34, 0xc9, 0x5f, 0x6c, 0x9f, 0xb8, 0xd2, 0xa9, 0x78, 0xa7, 0xaa, 0xb3,
+        0x11, 0x2f, 0x65, 0x9b, 0x4e, 0x67, 0x0c, 0xcc, 0x20, 0x36, 0xbf, 0x26,
+        0x2b, 0x4e, 0xc0, 0xd4, 0xbd, 0x22, 0x64, 0xc4, 0x1c, 0x56, 0x69, 0xdb,
+        0x5f, 0x89, 0xe1, 0x75, 0x68, 0x8d, 0x0e, 0xab, 0x1c, 0x10, 0x1a, 0xc0,
+        0x12, 0x5d, 0x6f, 0xbd, 0x09, 0xbb, 0x47, 0xcb, 0xe7, 0x34, 0xef, 0x56,
+        0xab, 0xea, 0xc3, 0xe9, 0x7f, 0x9a, 0x3d, 0xe9, 0x2d, 0x14, 0x61, 0x25,
+        0x37, 0x5c, 0x3b, 0x4b, 0xaf, 0x5a, 0x4b, 0xc8, 0x99, 0x1a, 0x32, 0x8f,
+        0x54, 0x07, 0xd3, 0x57, 0x8a, 0x3d, 0x2a, 0xf7, 0x9e, 0x7e, 0x92, 0x2a,
+        0x50, 0xe9, 0xd8, 0xdb, 0xd6, 0x03, 0xd3, 0x8e, 0x54, 0x32, 0xce, 0x87,
+        0x93, 0x92, 0xe7, 0x75, 0xe1, 0x6b, 0x78, 0x1a, 0x85, 0xc2, 0x46, 0xa1,
+        0x31, 0xbb, 0xc7, 0xb9, 0x1d, 0xd1, 0x71, 0xe0, 0xe2, 0x9b, 0x9c, 0x0d,
+        0xa3, 0xcf, 0x93, 0x4d, 0x87, 0x7b, 0x65, 0xd9, 0xda, 0x4c, 0xd9, 0x6a,
+        0xa6, 0x36, 0xc2, 0xc7, 0xe3, 0x33, 0xe2, 0xc3, 0x83, 0xd1, 0x72, 0x54,
+        0x30, 0x81, 0x5e, 0x34, 0x2c, 0x61, 0xee, 0xf4, 0x48, 0x97, 0xb6, 0xaa,
+        0x47, 0x6a, 0x05, 0x09, 0xd8, 0x4d, 0x90, 0xaf, 0xa8, 0x4e, 0x82, 0xe4,
+        0x8e, 0xb5, 0xe2, 0x65, 0x86, 0x67, 0xe9, 0x5b, 0x4b, 0x9a, 0x68, 0x08,
+        0x30, 0xf6, 0x25, 0x8b, 0x20, 0xda, 0x26, 0x6f, 0xbd, 0x0d, 0xa5, 0xd8,
+        0x6a, 0x7b, 0x01, 0x2f, 0xab, 0x7b, 0xb5, 0xfe, 0x62, 0x37, 0x2d, 0x94,
+        0x43, 0x2f, 0x4d, 0x16, 0x01, 0x00, 0x01, 0x00,
+};
+
+// 2048 bit RSA signature.
+const uint8_t kSignature2048[ANDROID_PUBKEY_MODULUS_SIZE] = {
+        0x3a, 0x11, 0x84, 0x40, 0xc1, 0x2f, 0x13, 0x8c, 0xde, 0xb0, 0xc3, 0x89,
+        0x8a, 0x63, 0xb2, 0x50, 0x93, 0x58, 0xc0, 0x0c, 0xb7, 0x08, 0xe7, 0x6c,
+        0x52, 0x87, 0x4e, 0x78, 0x89, 0xa3, 0x9a, 0x47, 0xeb, 0x11, 0x57, 0xbc,
+        0xb3, 0x97, 0xf8, 0x34, 0xf1, 0xf7, 0xbf, 0x3a, 0xfa, 0x1c, 0x6b, 0xdc,
+        0xd1, 0x02, 0xde, 0x9a, 0x0d, 0x72, 0xe7, 0x19, 0x63, 0x81, 0x46, 0x68,
+        0x1e, 0x63, 0x64, 0xc6, 0x59, 0xe7, 0x7c, 0x39, 0xed, 0x32, 0xd2, 0xd1,
+        0xd5, 0x1f, 0x13, 0x9b, 0x52, 0xdf, 0x34, 0xa3, 0xc0, 0xc4, 0x9a, 0x63,
+        0x9b, 0x9c, 0xbe, 0x22, 0xc8, 0xd8, 0x14, 0x2f, 0x4c, 0x78, 0x36, 0xdb,
+        0x16, 0x41, 0x67, 0xc1, 0x21, 0x8a, 0x73, 0xb2, 0xe5, 0xb0, 0xd3, 0x80,
+        0x91, 0x7a, 0xbf, 0xf9, 0x59, 0x4a, 0x4d, 0x78, 0x45, 0x44, 0xa1, 0x52,
+        0x86, 0x29, 0x48, 0x4d, 0xf0, 0x5d, 0xf2, 0x55, 0xa7, 0xcd, 0xc5, 0x2b,
+        0x7b, 0xe0, 0xb1, 0xf6, 0x2a, 0xd5, 0x61, 0xba, 0x1e, 0x1e, 0x3a, 0xf0,
+        0x55, 0xbc, 0x8c, 0x44, 0x41, 0xfc, 0xb8, 0x8c, 0x76, 0xbf, 0x80, 0x58,
+        0x82, 0x35, 0x4b, 0x0c, 0xfd, 0xef, 0xd5, 0x70, 0xd1, 0x64, 0xcb, 0x46,
+        0x58, 0x37, 0xbc, 0xa9, 0x7d, 0xd4, 0x70, 0xac, 0xce, 0xec, 0xca, 0x48,
+        0xcb, 0x0a, 0x40, 0x77, 0x04, 0x59, 0xca, 0x9c, 0x7d, 0x1a, 0x0b, 0xf0,
+        0xb5, 0xdd, 0xde, 0x71, 0x18, 0xb8, 0xef, 0x90, 0x2a, 0x09, 0x42, 0x39,
+        0x74, 0xff, 0x45, 0xa1, 0x39, 0x17, 0x50, 0x89, 0xa6, 0x5f, 0xbc, 0x9c,
+        0x0c, 0x9b, 0x47, 0x25, 0x79, 0x3e, 0xe3, 0xaa, 0xaf, 0xbe, 0x73, 0x6b,
+        0xcb, 0xe7, 0x35, 0xc1, 0x27, 0x09, 0xcd, 0xeb, 0xd7, 0xcf, 0x63, 0x83,
+        0x64, 0x8c, 0x45, 0x1c, 0x1d, 0x58, 0xcc, 0xd2, 0xf8, 0x2b, 0x4c, 0x4e,
+        0x14, 0x89, 0x2d, 0x70,
+};
+
+struct AndroidPubkeyTest : public ::testing::Test {
+    void SetUp() override {
+        RSA* new_key = nullptr;
+        android_pubkey_decode(kKey2048, sizeof(kKey2048), &new_key);
+        key_.reset(new_key);
+    }
+
+    std::unique_ptr<RSA, void (*)(RSA*)> key_ = {nullptr, RSA_free};
+};
+
+TEST_F(AndroidPubkeyTest, Decode) {
+    // Make sure the decoded key successfully verifies a valid signature.
+    EXPECT_TRUE(RSA_verify(NID_sha256, kDigest, sizeof(kDigest), kSignature2048,
+                           sizeof(kSignature2048), key_.get()));
+}
+
+TEST_F(AndroidPubkeyTest, Encode) {
+    //uint8_t key_data[ANDROID_PUBKEY_ENCODED_SIZE];
+    uint8_t key_data[ANDROID_PUBKEY_ENCODED_SIZE];
+    ASSERT_TRUE(android_pubkey_encode(key_.get(), key_data, sizeof(key_data)));
+    ASSERT_EQ(0, memcmp(kKey2048, key_data, sizeof(kKey2048)));
+}
+
+}  // namespace base
+}  // namespace android