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Remove the load_keys function

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This function is used to parse the result of dumpKeys. It's no longer
needed as we are now parsing the public keys from the zipfile.

Bug: 116655889
Test: unit tests pass
Change-Id: I817906e451664058c644f4329ff499bbe4587ebb
This commit is contained in:
Tianjie Xu 2018-10-19 17:23:21 -07:00
parent b5110de1b3
commit cbe93e6506
3 changed files with 9 additions and 326 deletions
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84
tests/component/verifier_test.cpp
View file

@ -238,8 +238,9 @@ class VerifierTest : public testing::TestWithParam<std::vector<std::string>> {
}
for (auto it = ++args.cbegin(); it != args.cend(); ++it) {
std::string public_key_file = from_testdata_base("testkey_" + *it + ".txt");
ASSERT_TRUE(load_keys(public_key_file.c_str(), certs));
std::string public_key_file = from_testdata_base("testkey_" + *it + ".x509.pem");
certs.emplace_back(0, Certificate::KEY_TYPE_RSA, nullptr, nullptr);
LoadKeyFromFile(public_key_file, &certs.back());
}
}
@ -253,70 +254,10 @@ class VerifierSuccessTest : public VerifierTest {
class VerifierFailureTest : public VerifierTest {
};
TEST(VerifierTest, load_keys_multiple_keys) {
std::string testkey_v4;
ASSERT_TRUE(android::base::ReadFileToString(from_testdata_base("testkey_v4.txt"), &testkey_v4));
std::string testkey_v3;
ASSERT_TRUE(android::base::ReadFileToString(from_testdata_base("testkey_v3.txt"), &testkey_v3));
std::string keys = testkey_v4 + "," + testkey_v3 + "," + testkey_v4;
TemporaryFile key_file1;
ASSERT_TRUE(android::base::WriteStringToFile(keys, key_file1.path));
std::vector<Certificate> certs;
ASSERT_TRUE(load_keys(key_file1.path, certs));
ASSERT_EQ(3U, certs.size());
}
TEST(VerifierTest, load_keys_invalid_keys) {
std::vector<Certificate> certs;
ASSERT_FALSE(load_keys("/doesntexist", certs));
// Empty file.
TemporaryFile key_file1;
ASSERT_FALSE(load_keys(key_file1.path, certs));
// Invalid contents.
ASSERT_TRUE(android::base::WriteStringToFile("invalid", key_file1.path));
ASSERT_FALSE(load_keys(key_file1.path, certs));
std::string testkey_v4;
ASSERT_TRUE(android::base::ReadFileToString(from_testdata_base("testkey_v4.txt"), &testkey_v4));
// Invalid key version: "v4 ..." => "v6 ...".
std::string invalid_key2(testkey_v4);
invalid_key2[1] = '6';
TemporaryFile key_file2;
ASSERT_TRUE(android::base::WriteStringToFile(invalid_key2, key_file2.path));
ASSERT_FALSE(load_keys(key_file2.path, certs));
// Invalid key content: inserted extra bytes ",2209831334".
std::string invalid_key3(testkey_v4);
invalid_key3.insert(invalid_key2.size() - 2, ",2209831334");
TemporaryFile key_file3;
ASSERT_TRUE(android::base::WriteStringToFile(invalid_key3, key_file3.path));
ASSERT_FALSE(load_keys(key_file3.path, certs));
// Invalid key: the last key must not end with an extra ','.
std::string invalid_key4 = testkey_v4 + ",";
TemporaryFile key_file4;
ASSERT_TRUE(android::base::WriteStringToFile(invalid_key4, key_file4.path));
ASSERT_FALSE(load_keys(key_file4.path, certs));
// Invalid key separator.
std::string invalid_key5 = testkey_v4 + ";" + testkey_v4;
TemporaryFile key_file5;
ASSERT_TRUE(android::base::WriteStringToFile(invalid_key5, key_file5.path));
ASSERT_FALSE(load_keys(key_file5.path, certs));
}
TEST(VerifierTest, BadPackage_AlteredFooter) {
std::string testkey_v3;
ASSERT_TRUE(android::base::ReadFileToString(from_testdata_base("testkey_v3.txt"), &testkey_v3));
TemporaryFile key_file1;
ASSERT_TRUE(android::base::WriteStringToFile(testkey_v3, key_file1.path));
std::vector<Certificate> certs;
ASSERT_TRUE(load_keys(key_file1.path, certs));
certs.emplace_back(0, Certificate::KEY_TYPE_RSA, nullptr, nullptr);
LoadKeyFromFile(from_testdata_base("testkey_v3.x509.pem"), &certs.back());
std::string package;
ASSERT_TRUE(android::base::ReadFileToString(from_testdata_base("otasigned_v3.zip"), &package));
@ -330,12 +271,9 @@ TEST(VerifierTest, BadPackage_AlteredFooter) {
}
TEST(VerifierTest, BadPackage_AlteredContent) {
std::string testkey_v3;
ASSERT_TRUE(android::base::ReadFileToString(from_testdata_base("testkey_v3.txt"), &testkey_v3));
TemporaryFile key_file1;
ASSERT_TRUE(android::base::WriteStringToFile(testkey_v3, key_file1.path));
std::vector<Certificate> certs;
ASSERT_TRUE(load_keys(key_file1.path, certs));
certs.emplace_back(0, Certificate::KEY_TYPE_RSA, nullptr, nullptr);
LoadKeyFromFile(from_testdata_base("testkey_v3.x509.pem"), &certs.back());
std::string package;
ASSERT_TRUE(android::base::ReadFileToString(from_testdata_base("otasigned_v3.zip"), &package));
@ -356,13 +294,9 @@ TEST(VerifierTest, BadPackage_AlteredContent) {
}
TEST(VerifierTest, BadPackage_SignatureStartOutOfBounds) {
std::string testkey_v3;
ASSERT_TRUE(android::base::ReadFileToString(from_testdata_base("testkey_v3.txt"), &testkey_v3));
TemporaryFile key_file;
ASSERT_TRUE(android::base::WriteStringToFile(testkey_v3, key_file.path));
std::vector<Certificate> certs;
ASSERT_TRUE(load_keys(key_file.path, certs));
certs.emplace_back(0, Certificate::KEY_TYPE_RSA, nullptr, nullptr);
LoadKeyFromFile(from_testdata_base("testkey_v3.x509.pem"), &certs.back());
// Signature start is 65535 (0xffff) while comment size is 0 (Bug: 31914369).
std::string package = "\x50\x4b\x05\x06"s + std::string(12, '\0') + "\xff\xff\xff\xff\x00\x00"s;

249
verifier.cpp
View file

@ -308,144 +308,6 @@ int verify_file(const unsigned char* addr, size_t length, const std::vector<Cert
return VERIFY_FAILURE;
}
std::unique_ptr<RSA, RSADeleter> parse_rsa_key(FILE* file, uint32_t exponent) {
// Read key length in words and n0inv. n0inv is a precomputed montgomery
// parameter derived from the modulus and can be used to speed up
// verification. n0inv is 32 bits wide here, assuming the verification logic
// uses 32 bit arithmetic. However, BoringSSL may use a word size of 64 bits
// internally, in which case we don't have a valid n0inv. Thus, we just
// ignore the montgomery parameters and have BoringSSL recompute them
// internally. If/When the speedup from using the montgomery parameters
// becomes relevant, we can add more sophisticated code here to obtain a
// 64-bit n0inv and initialize the montgomery parameters in the key object.
uint32_t key_len_words = 0;
uint32_t n0inv = 0;
if (fscanf(file, " %i , 0x%x", &key_len_words, &n0inv) != 2) {
return nullptr;
}
if (key_len_words > 8192 / 32) {
LOG(ERROR) << "key length (" << key_len_words << ") too large";
return nullptr;
}
// Read the modulus.
std::unique_ptr<uint32_t[]> modulus(new uint32_t[key_len_words]);
if (fscanf(file, " , { %u", &modulus[0]) != 1) {
return nullptr;
}
for (uint32_t i = 1; i < key_len_words; ++i) {
if (fscanf(file, " , %u", &modulus[i]) != 1) {
return nullptr;
}
}
// Cconvert from little-endian array of little-endian words to big-endian
// byte array suitable as input for BN_bin2bn.
std::reverse((uint8_t*)modulus.get(),
(uint8_t*)(modulus.get() + key_len_words));
// The next sequence of values is the montgomery parameter R^2. Since we
// generally don't have a valid |n0inv|, we ignore this (see comment above).
uint32_t rr_value;
if (fscanf(file, " } , { %u", &rr_value) != 1) {
return nullptr;
}
for (uint32_t i = 1; i < key_len_words; ++i) {
if (fscanf(file, " , %u", &rr_value) != 1) {
return nullptr;
}
}
if (fscanf(file, " } } ") != 0) {
return nullptr;
}
// Initialize the key.
std::unique_ptr<RSA, RSADeleter> key(RSA_new());
if (!key) {
return nullptr;
}
key->n = BN_bin2bn((uint8_t*)modulus.get(),
key_len_words * sizeof(uint32_t), NULL);
if (!key->n) {
return nullptr;
}
key->e = BN_new();
if (!key->e || !BN_set_word(key->e, exponent)) {
return nullptr;
}
return key;
}
struct BNDeleter {
void operator()(BIGNUM* bn) const {
BN_free(bn);
}
};
std::unique_ptr<EC_KEY, ECKEYDeleter> parse_ec_key(FILE* file) {
uint32_t key_len_bytes = 0;
if (fscanf(file, " %i", &key_len_bytes) != 1) {
return nullptr;
}
std::unique_ptr<EC_GROUP, void (*)(EC_GROUP*)> group(
EC_GROUP_new_by_curve_name(NID_X9_62_prime256v1), EC_GROUP_free);
if (!group) {
return nullptr;
}
// Verify that |key_len| matches the group order.
if (key_len_bytes != BN_num_bytes(EC_GROUP_get0_order(group.get()))) {
return nullptr;
}
// Read the public key coordinates. Note that the byte order in the file is
// little-endian, so we convert to big-endian here.
std::unique_ptr<uint8_t[]> bytes(new uint8_t[key_len_bytes]);
std::unique_ptr<BIGNUM, BNDeleter> point[2];
for (int i = 0; i < 2; ++i) {
unsigned int byte = 0;
if (fscanf(file, " , { %u", &byte) != 1) {
return nullptr;
}
bytes[key_len_bytes - 1] = byte;
for (size_t i = 1; i < key_len_bytes; ++i) {
if (fscanf(file, " , %u", &byte) != 1) {
return nullptr;
}
bytes[key_len_bytes - i - 1] = byte;
}
point[i].reset(BN_bin2bn(bytes.get(), key_len_bytes, nullptr));
if (!point[i]) {
return nullptr;
}
if (fscanf(file, " }") != 0) {
return nullptr;
}
}
if (fscanf(file, " } ") != 0) {
return nullptr;
}
// Create and initialize the key.
std::unique_ptr<EC_KEY, ECKEYDeleter> key(EC_KEY_new());
if (!key || !EC_KEY_set_group(key.get(), group.get()) ||
!EC_KEY_set_public_key_affine_coordinates(key.get(), point[0].get(),
point[1].get())) {
return nullptr;
}
return key;
}
static std::vector<Certificate> IterateZipEntriesAndSearchForKeys(const ZipArchiveHandle& handle) {
void* cookie;
ZipString suffix("x509.pem");
@ -603,114 +465,3 @@ bool LoadCertificateFromBuffer(const std::vector<uint8_t>& pem_content, Certific
return true;
}
// Reads a file containing one or more public keys as produced by
// DumpPublicKey: this is an RSAPublicKey struct as it would appear
// as a C source literal, eg:
//
// "{64,0xc926ad21,{1795090719,...,-695002876},{-857949815,...,1175080310}}"
//
// For key versions newer than the original 2048-bit e=3 keys
// supported by Android, the string is preceded by a version
// identifier, eg:
//
// "v2 {64,0xc926ad21,{1795090719,...,-695002876},{-857949815,...,1175080310}}"
//
// (Note that the braces and commas in this example are actual
// characters the parser expects to find in the file; the ellipses
// indicate more numbers omitted from this example.)
//
// The file may contain multiple keys in this format, separated by
// commas. The last key must not be followed by a comma.
//
// A Certificate is a pair of an RSAPublicKey and a particular hash
// (we support SHA-1 and SHA-256; we store the hash length to signify
// which is being used). The hash used is implied by the version number.
//
// 1: 2048-bit RSA key with e=3 and SHA-1 hash
// 2: 2048-bit RSA key with e=65537 and SHA-1 hash
// 3: 2048-bit RSA key with e=3 and SHA-256 hash
// 4: 2048-bit RSA key with e=65537 and SHA-256 hash
// 5: 256-bit EC key using the NIST P-256 curve parameters and SHA-256 hash
//
// Returns true on success, and appends the found keys (at least one) to certs.
// Otherwise returns false if the file failed to parse, or if it contains zero
// keys. The contents in certs would be unspecified on failure.
bool load_keys(const char* filename, std::vector<Certificate>& certs) {
std::unique_ptr<FILE, decltype(&fclose)> f(fopen(filename, "re"), fclose);
if (!f) {
PLOG(ERROR) << "error opening " << filename;
return false;
}
while (true) {
certs.emplace_back(0, Certificate::KEY_TYPE_RSA, nullptr, nullptr);
Certificate& cert = certs.back();
uint32_t exponent = 0;
char start_char;
if (fscanf(f.get(), " %c", &start_char) != 1) return false;
if (start_char == '{') {
// a version 1 key has no version specifier.
cert.key_type = Certificate::KEY_TYPE_RSA;
exponent = 3;
cert.hash_len = SHA_DIGEST_LENGTH;
} else if (start_char == 'v') {
int version;
if (fscanf(f.get(), "%d {", &version) != 1) return false;
switch (version) {
case 2:
cert.key_type = Certificate::KEY_TYPE_RSA;
exponent = 65537;
cert.hash_len = SHA_DIGEST_LENGTH;
break;
case 3:
cert.key_type = Certificate::KEY_TYPE_RSA;
exponent = 3;
cert.hash_len = SHA256_DIGEST_LENGTH;
break;
case 4:
cert.key_type = Certificate::KEY_TYPE_RSA;
exponent = 65537;
cert.hash_len = SHA256_DIGEST_LENGTH;
break;
case 5:
cert.key_type = Certificate::KEY_TYPE_EC;
cert.hash_len = SHA256_DIGEST_LENGTH;
break;
default:
return false;
}
}
if (cert.key_type == Certificate::KEY_TYPE_RSA) {
cert.rsa = parse_rsa_key(f.get(), exponent);
if (!cert.rsa) {
return false;
}
LOG(INFO) << "read key e=" << exponent << " hash=" << cert.hash_len;
} else if (cert.key_type == Certificate::KEY_TYPE_EC) {
cert.ec = parse_ec_key(f.get());
if (!cert.ec) {
return false;
}
} else {
LOG(ERROR) << "Unknown key type " << cert.key_type;
return false;
}
// if the line ends in a comma, this file has more keys.
int ch = fgetc(f.get());
if (ch == ',') {
// more keys to come.
continue;
} else if (ch == EOF) {
break;
} else {
LOG(ERROR) << "unexpected character between keys";
return false;
}
}
return true;
}

2
verifier.h
View file

@ -70,8 +70,6 @@ struct Certificate {
int verify_file(const unsigned char* addr, size_t length, const std::vector<Certificate>& keys,
const std::function<void(float)>& set_progress = nullptr);
bool load_keys(const char* filename, std::vector<Certificate>& certs);
// Checks that the RSA key has a modulus of 2048 bits long, and public exponent is 3 or 65537.
bool CheckRSAKey(const std::unique_ptr<RSA, RSADeleter>& rsa);