You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
220 lines
9.3 KiB
220 lines
9.3 KiB
/*
|
|
* Copyright 2015 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 <keymaster/km_openssl/nist_curve_key_exchange.h>
|
|
|
|
#include <gtest/gtest.h>
|
|
#include <openssl/evp.h>
|
|
|
|
#include <hardware/keymaster_defs.h>
|
|
#include <keymaster/android_keymaster_utils.h>
|
|
|
|
#include "android_keymaster_test_utils.h"
|
|
|
|
using std::string;
|
|
|
|
namespace keymaster {
|
|
namespace test {
|
|
|
|
static const keymaster_ec_curve_t kEcCurves[] = {KM_EC_CURVE_P_224, KM_EC_CURVE_P_256,
|
|
KM_EC_CURVE_P_384, KM_EC_CURVE_P_521};
|
|
|
|
/**
|
|
* SharedKey just tests that the basic key exchange identity holds: that both
|
|
* parties end up with the same key.
|
|
*/
|
|
TEST(NistCurveKeyExchange, SharedKey) {
|
|
for (auto& curve : kEcCurves) {
|
|
AuthorizationSet kex_description(
|
|
AuthorizationSetBuilder().Authorization(TAG_EC_CURVE, curve));
|
|
for (size_t j = 0; j < 5; j++) {
|
|
NistCurveKeyExchange* alice_keyex = NistCurveKeyExchange::GenerateKeyExchange(curve);
|
|
NistCurveKeyExchange* bob_keyex = NistCurveKeyExchange::GenerateKeyExchange(curve);
|
|
|
|
ASSERT_TRUE(alice_keyex != nullptr);
|
|
ASSERT_TRUE(bob_keyex != nullptr);
|
|
|
|
Buffer alice_public_value;
|
|
ASSERT_TRUE(alice_keyex->public_value(&alice_public_value));
|
|
Buffer bob_public_value;
|
|
ASSERT_TRUE(bob_keyex->public_value(&bob_public_value));
|
|
|
|
Buffer alice_shared, bob_shared;
|
|
ASSERT_TRUE(alice_keyex->CalculateSharedKey(bob_public_value, &alice_shared));
|
|
ASSERT_TRUE(bob_keyex->CalculateSharedKey(alice_public_value, &bob_shared));
|
|
EXPECT_EQ(alice_shared.available_read(), bob_shared.available_read());
|
|
EXPECT_EQ(0, memcmp(alice_shared.peek_read(), bob_shared.peek_read(),
|
|
alice_shared.available_read()));
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* This test tries a key agreement with a false public key (i.e. with
|
|
* a point not on the curve.)
|
|
* The expected result of such a protocol should be that the
|
|
* key agreement fails and returns an error.
|
|
*/
|
|
static const char* kInvalidPublicKeys[] = {
|
|
"04" // uncompressed public key
|
|
"deadbeef7f56584c5cc632ca65640db91b6bacce3a4df6b42ce7cc838833d287"
|
|
"db71e509e3fd9b060ddb20ba5c51dcc5948d46fbf640dfe0441782cab85fa4ac",
|
|
};
|
|
|
|
TEST(NistCurveKeyExchange, InvalidPublicKey) {
|
|
for (auto& curve : kEcCurves) {
|
|
AuthorizationSet kex_description(
|
|
AuthorizationSetBuilder().Authorization(TAG_EC_CURVE, curve));
|
|
KeyExchange* key_exchange = NistCurveKeyExchange::GenerateKeyExchange(curve);
|
|
ASSERT_TRUE(key_exchange != nullptr);
|
|
|
|
string peer_public_key = hex2str(kInvalidPublicKeys[0]);
|
|
Buffer computed_shared_secret;
|
|
ASSERT_FALSE(key_exchange->CalculateSharedKey(
|
|
reinterpret_cast<const uint8_t*>(peer_public_key.data()), peer_public_key.size(),
|
|
&computed_shared_secret));
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Test that key exchange fails when peer public key is the point at infinity.
|
|
*/
|
|
TEST(NistCurveKeyExchange, TestInfinity) {
|
|
for (auto& curve : kEcCurves) {
|
|
/* Obtain the point at infinity */
|
|
EC_GROUP* group = ec_get_group(curve);
|
|
EC_POINT* point_at_infinity = EC_POINT_new(group);
|
|
EC_POINT_set_to_infinity(group, point_at_infinity);
|
|
EXPECT_EQ(1, EC_POINT_is_on_curve(group, point_at_infinity, nullptr));
|
|
size_t field_len_in_bits;
|
|
ec_get_group_size(group, &field_len_in_bits);
|
|
size_t field_len = (field_len_in_bits + 7) / 8;
|
|
size_t public_key_len = (field_len * 2) + 1;
|
|
uint8_t* public_key = new uint8_t[public_key_len];
|
|
public_key_len = EC_POINT_point2oct(group, point_at_infinity, POINT_CONVERSION_UNCOMPRESSED,
|
|
public_key, public_key_len, nullptr /* ctx */);
|
|
|
|
/* Perform the key exchange */
|
|
AuthorizationSet kex_description(
|
|
AuthorizationSetBuilder().Authorization(TAG_EC_CURVE, curve));
|
|
NistCurveKeyExchange* key_exchange = NistCurveKeyExchange::GenerateKeyExchange(curve);
|
|
ASSERT_TRUE(key_exchange != nullptr);
|
|
Buffer computed_shared_secret;
|
|
/* It should fail */
|
|
ASSERT_FALSE(key_exchange->CalculateSharedKey(reinterpret_cast<const uint8_t*>(public_key),
|
|
public_key_len, &computed_shared_secret));
|
|
|
|
/* Explicitly test that ECDH_compute_key fails when the public key is the point at infinity
|
|
*/
|
|
UniquePtr<uint8_t[]> result(new uint8_t[field_len]);
|
|
EXPECT_EQ(-1 /* error */, ECDH_compute_key(result.get(), field_len, point_at_infinity,
|
|
key_exchange->private_key(), nullptr /* kdf */));
|
|
}
|
|
}
|
|
|
|
/* Test vectors for P-256, downloaded from NIST. */
|
|
struct NistCurveTest {
|
|
const keymaster_ec_curve_t curve;
|
|
const char* peer_public_key;
|
|
const char* my_private_key;
|
|
const char* shared_secret;
|
|
};
|
|
|
|
static const NistCurveTest kNistCurveTests[] = {
|
|
{
|
|
KM_EC_CURVE_P_256,
|
|
"04" // uncompressed public key
|
|
"700c48f77f56584c5cc632ca65640db91b6bacce3a4df6b42ce7cc838833d287"
|
|
"db71e509e3fd9b060ddb20ba5c51dcc5948d46fbf640dfe0441782cab85fa4ac",
|
|
// https://tools.ietf.org/html/rfc5915
|
|
"30770201010420" // DER-encodeded EC private key header
|
|
"7d7dc5f71eb29ddaf80d6214632eeae03d9058af1fb6d22ed80badb62bc1a534" // private key
|
|
"a00a06082a8648ce3d030107a144034200" // DER-encoded curve OID,
|
|
"04"
|
|
"ead218590119e8876b29146ff89ca61770c4edbbf97d38ce385ed281d8a6b230"
|
|
"28af61281fd35e2fa7002523acc85a429cb06ee6648325389f59edfce1405141",
|
|
"46fc62106420ff012e54a434fbdd2d25ccc5852060561e68040dd7778997bd7b",
|
|
},
|
|
{
|
|
KM_EC_CURVE_P_256,
|
|
"04"
|
|
"809f04289c64348c01515eb03d5ce7ac1a8cb9498f5caa50197e58d43a86a7ae"
|
|
"b29d84e811197f25eba8f5194092cb6ff440e26d4421011372461f579271cda3",
|
|
// https://tools.ietf.org/html/rfc5915
|
|
"30770201010420" // DER-encodeded EC private key header
|
|
"38f65d6dce47676044d58ce5139582d568f64bb16098d179dbab07741dd5caf5" // private key
|
|
"a00a06082a8648ce3d030107a144034200" // DER-encoded curve OID,
|
|
"04"
|
|
"119f2f047902782ab0c9e27a54aff5eb9b964829ca99c06b02ddba95b0a3f6d0"
|
|
"8f52b726664cac366fc98ac7a012b2682cbd962e5acb544671d41b9445704d1d",
|
|
"057d636096cb80b67a8c038c890e887d1adfa4195e9b3ce241c8a778c59cda67",
|
|
},
|
|
{
|
|
KM_EC_CURVE_P_256,
|
|
"04"
|
|
"df3989b9fa55495719b3cf46dccd28b5153f7808191dd518eff0c3cff2b705ed"
|
|
"422294ff46003429d739a33206c8752552c8ba54a270defc06e221e0feaf6ac4",
|
|
// https://tools.ietf.org/html/rfc5915
|
|
"30770201010420" // DER-encodeded EC private key header
|
|
"207c43a79bfee03db6f4b944f53d2fb76cc49ef1c9c4d34d51b6c65c4db6932d" // private key
|
|
"a00a06082a8648ce3d030107a144034200" // DER-encoded curve OID,
|
|
"04"
|
|
"24277c33f450462dcb3d4801d57b9ced05188f16c28eda873258048cd1607e0d"
|
|
"c4789753e2b1f63b32ff014ec42cd6a69fac81dfe6d0d6fd4af372ae27c46f88",
|
|
"96441259534b80f6aee3d287a6bb17b5094dd4277d9e294f8fe73e48bf2a0024",
|
|
},
|
|
};
|
|
|
|
/**
|
|
* Test that key exchange works with NIST test vectors.
|
|
*/
|
|
TEST(NistCurveKeyExchange, NistTestVectors) {
|
|
for (auto& test : kNistCurveTests) {
|
|
string private_key = hex2str(test.my_private_key);
|
|
string shared_secret = hex2str(test.shared_secret);
|
|
|
|
const uint8_t* private_key_data = reinterpret_cast<const uint8_t*>(private_key.data());
|
|
UniquePtr<EC_KEY, EC_KEY_Delete> ec_key(
|
|
d2i_ECPrivateKey(nullptr, &private_key_data, private_key.size()));
|
|
ASSERT_TRUE(ec_key.get() && EC_KEY_check_key(ec_key.get()));
|
|
|
|
keymaster_error_t error;
|
|
NistCurveKeyExchange* key_exchange = new NistCurveKeyExchange(ec_key.release(), &error);
|
|
EXPECT_EQ(KM_ERROR_OK, error);
|
|
ASSERT_TRUE(key_exchange != nullptr);
|
|
|
|
Buffer computed_shared_secret;
|
|
string peer_public_key = hex2str(test.peer_public_key);
|
|
ASSERT_TRUE(key_exchange->CalculateSharedKey(
|
|
reinterpret_cast<const uint8_t*>(peer_public_key.data()), peer_public_key.size(),
|
|
&computed_shared_secret));
|
|
EXPECT_EQ(shared_secret.size(), computed_shared_secret.available_read());
|
|
EXPECT_EQ(0, memcmp(shared_secret.data(), computed_shared_secret.peek_read(),
|
|
shared_secret.size()));
|
|
|
|
for (size_t i = 0; i < peer_public_key.size(); i++) {
|
|
// randomly flip some bits in the peer public key to make it invalid
|
|
peer_public_key[i] ^= 0xff;
|
|
ASSERT_FALSE(key_exchange->CalculateSharedKey(
|
|
reinterpret_cast<const uint8_t*>(peer_public_key.data()), peer_public_key.size(),
|
|
&computed_shared_secret));
|
|
}
|
|
}
|
|
}
|
|
|
|
} // namespace test
|
|
} // namespace keymaster
|