1 /*
2  * Copyright (C) 2009 The Android Open Source Project
3  *
4  * Licensed under the Apache License, version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agree to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #include <errno.h>
18 #include <fcntl.h>
19 #include <stdio.h>
20 #include <stdlib.h>
21 #include <sys/stat.h>
22 #include <sys/types.h>
23 
24 #include <string>
25 #include <vector>
26 
27 #include <android-base/file.h>
28 #include <android-base/stringprintf.h>
29 #include <android-base/strings.h>
30 #include <android-base/unique_fd.h>
31 #include <gtest/gtest.h>
32 #include <openssl/bn.h>
33 #include <openssl/ec.h>
34 #include <openssl/nid.h>
35 #include <ziparchive/zip_writer.h>
36 
37 #include "common/test_constants.h"
38 #include "install/package.h"
39 #include "install/verifier.h"
40 #include "otautil/sysutil.h"
41 
42 using namespace std::string_literals;
43 
LoadKeyFromFile(const std::string & file_name,Certificate * cert)44 static void LoadKeyFromFile(const std::string& file_name, Certificate* cert) {
45   std::string testkey_string;
46   ASSERT_TRUE(android::base::ReadFileToString(file_name, &testkey_string));
47   ASSERT_TRUE(LoadCertificateFromBuffer(
48       std::vector<uint8_t>(testkey_string.begin(), testkey_string.end()), cert));
49 }
50 
VerifyFile(const std::string & content,const std::vector<Certificate> & keys,int expected)51 static void VerifyFile(const std::string& content, const std::vector<Certificate>& keys,
52                        int expected) {
53   auto package =
54       Package::CreateMemoryPackage(std::vector<uint8_t>(content.begin(), content.end()), nullptr);
55   ASSERT_NE(nullptr, package);
56 
57   ASSERT_EQ(expected, verify_file(package.get(), keys));
58 }
59 
VerifyPackageWithCertificates(const std::string & name,const std::vector<Certificate> & certs)60 static void VerifyPackageWithCertificates(const std::string& name,
61                                           const std::vector<Certificate>& certs) {
62   std::string path = from_testdata_base(name);
63   auto package = Package::CreateMemoryPackage(path, nullptr);
64   ASSERT_NE(nullptr, package);
65 
66   ASSERT_EQ(VERIFY_SUCCESS, verify_file(package.get(), certs));
67 }
68 
VerifyPackageWithSingleCertificate(const std::string & name,Certificate && cert)69 static void VerifyPackageWithSingleCertificate(const std::string& name, Certificate&& cert) {
70   std::vector<Certificate> certs;
71   certs.emplace_back(std::move(cert));
72   VerifyPackageWithCertificates(name, certs);
73 }
74 
BuildCertificateArchive(const std::vector<std::string> & file_names,int fd)75 static void BuildCertificateArchive(const std::vector<std::string>& file_names, int fd) {
76   FILE* zip_file_ptr = fdopen(fd, "wb");
77   ZipWriter zip_writer(zip_file_ptr);
78 
79   for (const auto& name : file_names) {
80     std::string content;
81     ASSERT_TRUE(android::base::ReadFileToString(name, &content));
82 
83     // Makes sure the zip entry name has the correct suffix.
84     std::string entry_name = name;
85     if (!android::base::EndsWith(entry_name, "x509.pem")) {
86       entry_name += "x509.pem";
87     }
88     ASSERT_EQ(0, zip_writer.StartEntry(entry_name.c_str(), ZipWriter::kCompress));
89     ASSERT_EQ(0, zip_writer.WriteBytes(content.data(), content.size()));
90     ASSERT_EQ(0, zip_writer.FinishEntry());
91   }
92 
93   ASSERT_EQ(0, zip_writer.Finish());
94   ASSERT_EQ(0, fclose(zip_file_ptr));
95 }
96 
TEST(VerifierTest,LoadCertificateFromBuffer_failure)97 TEST(VerifierTest, LoadCertificateFromBuffer_failure) {
98   Certificate cert(0, Certificate::KEY_TYPE_RSA, nullptr, nullptr);
99   std::string testkey_string;
100   ASSERT_TRUE(
101       android::base::ReadFileToString(from_testdata_base("testkey_v1.txt"), &testkey_string));
102   ASSERT_FALSE(LoadCertificateFromBuffer(
103       std::vector<uint8_t>(testkey_string.begin(), testkey_string.end()), &cert));
104 }
105 
TEST(VerifierTest,LoadCertificateFromBuffer_sha1_exponent3)106 TEST(VerifierTest, LoadCertificateFromBuffer_sha1_exponent3) {
107   Certificate cert(0, Certificate::KEY_TYPE_RSA, nullptr, nullptr);
108   LoadKeyFromFile(from_testdata_base("testkey_v1.x509.pem"), &cert);
109 
110   ASSERT_EQ(SHA_DIGEST_LENGTH, cert.hash_len);
111   ASSERT_EQ(Certificate::KEY_TYPE_RSA, cert.key_type);
112   ASSERT_EQ(nullptr, cert.ec);
113 
114   VerifyPackageWithSingleCertificate("otasigned_v1.zip", std::move(cert));
115 }
116 
TEST(VerifierTest,LoadCertificateFromBuffer_sha1_exponent65537)117 TEST(VerifierTest, LoadCertificateFromBuffer_sha1_exponent65537) {
118   Certificate cert(0, Certificate::KEY_TYPE_RSA, nullptr, nullptr);
119   LoadKeyFromFile(from_testdata_base("testkey_v2.x509.pem"), &cert);
120 
121   ASSERT_EQ(SHA_DIGEST_LENGTH, cert.hash_len);
122   ASSERT_EQ(Certificate::KEY_TYPE_RSA, cert.key_type);
123   ASSERT_EQ(nullptr, cert.ec);
124 
125   VerifyPackageWithSingleCertificate("otasigned_v2.zip", std::move(cert));
126 }
127 
TEST(VerifierTest,LoadCertificateFromBuffer_sha256_exponent3)128 TEST(VerifierTest, LoadCertificateFromBuffer_sha256_exponent3) {
129   Certificate cert(0, Certificate::KEY_TYPE_RSA, nullptr, nullptr);
130   LoadKeyFromFile(from_testdata_base("testkey_v3.x509.pem"), &cert);
131 
132   ASSERT_EQ(SHA256_DIGEST_LENGTH, cert.hash_len);
133   ASSERT_EQ(Certificate::KEY_TYPE_RSA, cert.key_type);
134   ASSERT_EQ(nullptr, cert.ec);
135 
136   VerifyPackageWithSingleCertificate("otasigned_v3.zip", std::move(cert));
137 }
138 
TEST(VerifierTest,LoadCertificateFromBuffer_sha256_exponent65537)139 TEST(VerifierTest, LoadCertificateFromBuffer_sha256_exponent65537) {
140   Certificate cert(0, Certificate::KEY_TYPE_RSA, nullptr, nullptr);
141   LoadKeyFromFile(from_testdata_base("testkey_v4.x509.pem"), &cert);
142 
143   ASSERT_EQ(SHA256_DIGEST_LENGTH, cert.hash_len);
144   ASSERT_EQ(Certificate::KEY_TYPE_RSA, cert.key_type);
145   ASSERT_EQ(nullptr, cert.ec);
146 
147   VerifyPackageWithSingleCertificate("otasigned_v4.zip", std::move(cert));
148 }
149 
TEST(VerifierTest,LoadCertificateFromBuffer_sha256_ec256bits)150 TEST(VerifierTest, LoadCertificateFromBuffer_sha256_ec256bits) {
151   Certificate cert(0, Certificate::KEY_TYPE_RSA, nullptr, nullptr);
152   LoadKeyFromFile(from_testdata_base("testkey_v5.x509.pem"), &cert);
153 
154   ASSERT_EQ(SHA256_DIGEST_LENGTH, cert.hash_len);
155   ASSERT_EQ(Certificate::KEY_TYPE_EC, cert.key_type);
156   ASSERT_EQ(nullptr, cert.rsa);
157 
158   VerifyPackageWithSingleCertificate("otasigned_v5.zip", std::move(cert));
159 }
160 
TEST(VerifierTest,LoadCertificateFromBuffer_sha256_rsa4096_bits)161 TEST(VerifierTest, LoadCertificateFromBuffer_sha256_rsa4096_bits) {
162   Certificate cert(0, Certificate::KEY_TYPE_RSA, nullptr, nullptr);
163   LoadKeyFromFile(from_testdata_base("testkey_4096bits.x509.pem"), &cert);
164 
165   ASSERT_EQ(SHA256_DIGEST_LENGTH, cert.hash_len);
166   ASSERT_EQ(Certificate::KEY_TYPE_RSA, cert.key_type);
167   ASSERT_EQ(nullptr, cert.ec);
168 
169   VerifyPackageWithSingleCertificate("otasigned_4096bits.zip", std::move(cert));
170 }
171 
TEST(VerifierTest,LoadCertificateFromBuffer_check_rsa_keys)172 TEST(VerifierTest, LoadCertificateFromBuffer_check_rsa_keys) {
173   std::unique_ptr<RSA, RSADeleter> rsa(RSA_new());
174   std::unique_ptr<BIGNUM, decltype(&BN_free)> exponent(BN_new(), BN_free);
175   BN_set_word(exponent.get(), 3);
176   RSA_generate_key_ex(rsa.get(), 2048, exponent.get(), nullptr);
177   ASSERT_TRUE(CheckRSAKey(rsa));
178 
179   // Exponent is expected to be 3 or 65537
180   BN_set_word(exponent.get(), 17);
181   RSA_generate_key_ex(rsa.get(), 2048, exponent.get(), nullptr);
182   ASSERT_FALSE(CheckRSAKey(rsa));
183 
184   // Modulus is expected to be 2048.
185   BN_set_word(exponent.get(), 3);
186   RSA_generate_key_ex(rsa.get(), 1024, exponent.get(), nullptr);
187   ASSERT_FALSE(CheckRSAKey(rsa));
188 }
189 
TEST(VerifierTest,LoadCertificateFromBuffer_check_ec_keys)190 TEST(VerifierTest, LoadCertificateFromBuffer_check_ec_keys) {
191   std::unique_ptr<EC_KEY, ECKEYDeleter> ec(EC_KEY_new_by_curve_name(NID_X9_62_prime256v1));
192   ASSERT_EQ(1, EC_KEY_generate_key(ec.get()));
193   ASSERT_TRUE(CheckECKey(ec));
194 
195   // Expects 256-bit EC key with curve NIST P-256
196   ec.reset(EC_KEY_new_by_curve_name(NID_secp224r1));
197   ASSERT_EQ(1, EC_KEY_generate_key(ec.get()));
198   ASSERT_FALSE(CheckECKey(ec));
199 }
200 
TEST(VerifierTest,LoadKeysFromZipfile_empty_archive)201 TEST(VerifierTest, LoadKeysFromZipfile_empty_archive) {
202   TemporaryFile otacerts;
203   BuildCertificateArchive({}, otacerts.release());
204   std::vector<Certificate> certs = LoadKeysFromZipfile(otacerts.path);
205   ASSERT_TRUE(certs.empty());
206 }
207 
TEST(VerifierTest,LoadKeysFromZipfile_single_key)208 TEST(VerifierTest, LoadKeysFromZipfile_single_key) {
209   TemporaryFile otacerts;
210   BuildCertificateArchive({ from_testdata_base("testkey_v1.x509.pem") }, otacerts.release());
211   std::vector<Certificate> certs = LoadKeysFromZipfile(otacerts.path);
212   ASSERT_EQ(1, certs.size());
213 
214   VerifyPackageWithCertificates("otasigned_v1.zip", certs);
215 }
216 
TEST(VerifierTest,LoadKeysFromZipfile_corrupted_key)217 TEST(VerifierTest, LoadKeysFromZipfile_corrupted_key) {
218   TemporaryFile corrupted_key;
219   std::string content;
220   ASSERT_TRUE(android::base::ReadFileToString(from_testdata_base("testkey_v1.x509.pem"), &content));
221   content = "random-contents" + content;
222   ASSERT_TRUE(android::base::WriteStringToFd(content, corrupted_key.release()));
223 
224   TemporaryFile otacerts;
225   BuildCertificateArchive({ from_testdata_base("testkey_v2.x509.pem"), corrupted_key.path },
226                           otacerts.release());
227   std::vector<Certificate> certs = LoadKeysFromZipfile(otacerts.path);
228   ASSERT_EQ(0, certs.size());
229 }
230 
TEST(VerifierTest,LoadKeysFromZipfile_multiple_key)231 TEST(VerifierTest, LoadKeysFromZipfile_multiple_key) {
232   TemporaryFile otacerts;
233   BuildCertificateArchive(
234       {
235           from_testdata_base("testkey_v3.x509.pem"),
236           from_testdata_base("testkey_v4.x509.pem"),
237           from_testdata_base("testkey_v5.x509.pem"),
238 
239       },
240       otacerts.release());
241   std::vector<Certificate> certs = LoadKeysFromZipfile(otacerts.path);
242   ASSERT_EQ(3, certs.size());
243 
244   VerifyPackageWithCertificates("otasigned_v3.zip", certs);
245   VerifyPackageWithCertificates("otasigned_v4.zip", certs);
246   VerifyPackageWithCertificates("otasigned_v5.zip", certs);
247 }
248 
249 class VerifierTest : public testing::TestWithParam<std::vector<std::string>> {
250  protected:
SetUp()251   void SetUp() override {
252     std::vector<std::string> args = GetParam();
253     std::string path = from_testdata_base(args[0]);
254     memory_package_ = Package::CreateMemoryPackage(path, nullptr);
255     ASSERT_NE(nullptr, memory_package_);
256     file_package_ = Package::CreateFilePackage(path, nullptr);
257     ASSERT_NE(nullptr, file_package_);
258 
259     for (auto it = ++args.cbegin(); it != args.cend(); ++it) {
260       std::string public_key_file = from_testdata_base("testkey_" + *it + ".x509.pem");
261       certs_.emplace_back(0, Certificate::KEY_TYPE_RSA, nullptr, nullptr);
262       LoadKeyFromFile(public_key_file, &certs_.back());
263     }
264   }
265 
266   std::unique_ptr<Package> memory_package_;
267   std::unique_ptr<Package> file_package_;
268   std::vector<Certificate> certs_;
269 };
270 
271 class VerifierSuccessTest : public VerifierTest {
272 };
273 
274 class VerifierFailureTest : public VerifierTest {
275 };
276 
TEST(VerifierTest,BadPackage_AlteredFooter)277 TEST(VerifierTest, BadPackage_AlteredFooter) {
278   std::vector<Certificate> certs;
279   certs.emplace_back(0, Certificate::KEY_TYPE_RSA, nullptr, nullptr);
280   LoadKeyFromFile(from_testdata_base("testkey_v3.x509.pem"), &certs.back());
281 
282   std::string package;
283   ASSERT_TRUE(android::base::ReadFileToString(from_testdata_base("otasigned_v3.zip"), &package));
284   ASSERT_EQ(std::string("\xc0\x06\xff\xff\xd2\x06", 6), package.substr(package.size() - 6, 6));
285 
286   // Alter the footer.
287   package[package.size() - 5] = '\x05';
288   VerifyFile(package, certs, VERIFY_FAILURE);
289 }
290 
TEST(VerifierTest,BadPackage_AlteredContent)291 TEST(VerifierTest, BadPackage_AlteredContent) {
292   std::vector<Certificate> certs;
293   certs.emplace_back(0, Certificate::KEY_TYPE_RSA, nullptr, nullptr);
294   LoadKeyFromFile(from_testdata_base("testkey_v3.x509.pem"), &certs.back());
295 
296   std::string package;
297   ASSERT_TRUE(android::base::ReadFileToString(from_testdata_base("otasigned_v3.zip"), &package));
298   ASSERT_GT(package.size(), static_cast<size_t>(100));
299 
300   // Alter the content.
301   std::string altered1(package);
302   altered1[50] += 1;
303   VerifyFile(altered1, certs, VERIFY_FAILURE);
304 
305   std::string altered2(package);
306   altered2[10] += 1;
307   VerifyFile(altered2, certs, VERIFY_FAILURE);
308 }
309 
TEST(VerifierTest,BadPackage_SignatureStartOutOfBounds)310 TEST(VerifierTest, BadPackage_SignatureStartOutOfBounds) {
311   std::vector<Certificate> certs;
312   certs.emplace_back(0, Certificate::KEY_TYPE_RSA, nullptr, nullptr);
313   LoadKeyFromFile(from_testdata_base("testkey_v3.x509.pem"), &certs.back());
314 
315   // Signature start is 65535 (0xffff) while comment size is 0 (Bug: 31914369).
316   std::string package = "\x50\x4b\x05\x06"s + std::string(12, '\0') + "\xff\xff\xff\xff\x00\x00"s;
317   VerifyFile(package, certs, VERIFY_FAILURE);
318 }
319 
TEST_P(VerifierSuccessTest,VerifySucceed)320 TEST_P(VerifierSuccessTest, VerifySucceed) {
321   ASSERT_EQ(VERIFY_SUCCESS, verify_file(memory_package_.get(), certs_));
322   ASSERT_EQ(VERIFY_SUCCESS, verify_file(file_package_.get(), certs_));
323 }
324 
TEST_P(VerifierFailureTest,VerifyFailure)325 TEST_P(VerifierFailureTest, VerifyFailure) {
326   ASSERT_EQ(VERIFY_FAILURE, verify_file(memory_package_.get(), certs_));
327   ASSERT_EQ(VERIFY_FAILURE, verify_file(file_package_.get(), certs_));
328 }
329 
330 INSTANTIATE_TEST_CASE_P(SingleKeySuccess, VerifierSuccessTest,
331     ::testing::Values(
332       std::vector<std::string>({"otasigned_v1.zip", "v1"}),
333       std::vector<std::string>({"otasigned_v2.zip", "v2"}),
334       std::vector<std::string>({"otasigned_v3.zip", "v3"}),
335       std::vector<std::string>({"otasigned_v4.zip", "v4"}),
336       std::vector<std::string>({"otasigned_v5.zip", "v5"})));
337 
338 INSTANTIATE_TEST_CASE_P(MultiKeySuccess, VerifierSuccessTest,
339     ::testing::Values(
340       std::vector<std::string>({"otasigned_v1.zip", "v1", "v2"}),
341       std::vector<std::string>({"otasigned_v2.zip", "v5", "v2"}),
342       std::vector<std::string>({"otasigned_v3.zip", "v5", "v1", "v3"}),
343       std::vector<std::string>({"otasigned_v4.zip", "v5", "v1", "v4"}),
344       std::vector<std::string>({"otasigned_v5.zip", "v4", "v1", "v5"})));
345 
346 INSTANTIATE_TEST_CASE_P(WrongKey, VerifierFailureTest,
347     ::testing::Values(
348       std::vector<std::string>({"otasigned_v1.zip", "v2"}),
349       std::vector<std::string>({"otasigned_v2.zip", "v1"}),
350       std::vector<std::string>({"otasigned_v3.zip", "v5"}),
351       std::vector<std::string>({"otasigned_v4.zip", "v5"}),
352       std::vector<std::string>({"otasigned_v5.zip", "v3"})));
353 
354 INSTANTIATE_TEST_CASE_P(WrongHash, VerifierFailureTest,
355     ::testing::Values(
356       std::vector<std::string>({"otasigned_v1.zip", "v3"}),
357       std::vector<std::string>({"otasigned_v2.zip", "v4"}),
358       std::vector<std::string>({"otasigned_v3.zip", "v1"}),
359       std::vector<std::string>({"otasigned_v4.zip", "v2"})));
360 
361 INSTANTIATE_TEST_CASE_P(BadPackage, VerifierFailureTest,
362     ::testing::Values(
363       std::vector<std::string>({"random.zip", "v1"}),
364       std::vector<std::string>({"fake-eocd.zip", "v1"})));
365