Support for P256 curve in RKP for Strongbox (fb213d60) · Commits · e / os / android_hardware_interfaces

security/keymint/aidl/vts/functional/VtsRemotelyProvisionedComponentTests.cpp

+29 −14

Original line number	Diff line number	Diff line
		@@ -169,6 +169,7 @@ class VtsRemotelyProvisionedComponentTests : public testing::TestWithParam<std::
		provisionable_ = IRemotelyProvisionedComponent::fromBinder(binder);
		}
		ASSERT_NE(provisionable_, nullptr);
		ASSERT_TRUE(provisionable_->getHardwareInfo(&rpcHardwareInfo).isOk());
		}

		static vector<string> build_params() {
		@@ -178,6 +179,7 @@ class VtsRemotelyProvisionedComponentTests : public testing::TestWithParam<std::

		protected:
		std::shared_ptr<IRemotelyProvisionedComponent> provisionable_;
		RpcHardwareInfo rpcHardwareInfo;
		};

		/**
		@@ -341,11 +343,10 @@ TEST_P(GenerateKeyTests, generateEcdsaP256Key_testMode) {
		class CertificateRequestTest : public VtsRemotelyProvisionedComponentTests {
		protected:
		CertificateRequestTest() : eekId_(string_to_bytevec("eekid")), challenge_(randomBytes(32)) {
		generateTestEekChain(3);
		}

		void generateTestEekChain(size_t eekLength) {
		auto chain = generateEekChain(eekLength, eekId_);
		auto chain = generateEekChain(rpcHardwareInfo.supportedEekCurve, eekLength, eekId_);
		EXPECT_TRUE(chain) << chain.message();
		if (chain) testEekChain_ = chain.moveValue();
		testEekLength_ = eekLength;
		@@ -366,6 +367,17 @@ class CertificateRequestTest : public VtsRemotelyProvisionedComponentTests {
		}
		}

		ErrMsgOr<bytevec> getSessionKey(ErrMsgOr<std::pair<bytevec, bytevec>>& senderPubkey) {
		if (rpcHardwareInfo.supportedEekCurve == RpcHardwareInfo::CURVE_25519 \|\|
		rpcHardwareInfo.supportedEekCurve == RpcHardwareInfo::CURVE_NONE) {
		return x25519_HKDF_DeriveKey(testEekChain_.last_pubkey, testEekChain_.last_privkey,
		senderPubkey->first, false /* senderIsA */);
		} else {
		return ECDH_HKDF_DeriveKey(testEekChain_.last_pubkey, testEekChain_.last_privkey,
		senderPubkey->first, false /* senderIsA */);
		}
		}

		void checkProtectedData(const DeviceInfo& deviceInfo, const cppbor::Array& keysToSign,
		const bytevec& keysToSignMac, const ProtectedData& protectedData,
		std::vector<BccEntryData>* bccOutput = nullptr) {
		@@ -378,9 +390,7 @@ class CertificateRequestTest : public VtsRemotelyProvisionedComponentTests {
		ASSERT_TRUE(senderPubkey) << senderPubkey.message();
		EXPECT_EQ(senderPubkey->second, eekId_);

		auto sessionKey =
		x25519_HKDF_DeriveKey(testEekChain_.last_pubkey, testEekChain_.last_privkey,
		senderPubkey->first, false /* senderIsA */);
		auto sessionKey = getSessionKey(senderPubkey);
		ASSERT_TRUE(sessionKey) << sessionKey.message();

		auto protectedDataPayload =
		@@ -390,7 +400,8 @@ class CertificateRequestTest : public VtsRemotelyProvisionedComponentTests {
		auto [parsedPayload, __, payloadErrMsg] = cppbor::parse(*protectedDataPayload);
		ASSERT_TRUE(parsedPayload) << "Failed to parse payload: " << payloadErrMsg;
		ASSERT_TRUE(parsedPayload->asArray());
		EXPECT_EQ(parsedPayload->asArray()->size(), 2U);
		// Strongbox may contain additional certificate chain.
		EXPECT_LE(parsedPayload->asArray()->size(), 3U);

		auto& signedMac = parsedPayload->asArray()->get(0);
		auto& bcc = parsedPayload->asArray()->get(1);
		@@ -474,6 +485,7 @@ TEST_P(CertificateRequestTest, NewKeyPerCallInTestMode) {
		bytevec keysToSignMac;
		DeviceInfo deviceInfo;
		ProtectedData protectedData;
		generateTestEekChain(3);
		auto status = provisionable_->generateCertificateRequest(
		testMode, {} /* keysToSign */, testEekChain_.chain, challenge_, &deviceInfo,
		&protectedData, &keysToSignMac);
		@@ -513,8 +525,8 @@ TEST_P(CertificateRequestTest, DISABLED_EmptyRequest_prodMode) {
		DeviceInfo deviceInfo;
		ProtectedData protectedData;
		auto status = provisionable_->generateCertificateRequest(
		testMode, {} /* keysToSign */, getProdEekChain(), challenge_, &deviceInfo,
		&protectedData, &keysToSignMac);
		testMode, {} /* keysToSign */, getProdEekChain(rpcHardwareInfo.supportedEekCurve),
		challenge_, &deviceInfo, &protectedData, &keysToSignMac);
		EXPECT_TRUE(status.isOk());
		}

		@@ -554,8 +566,8 @@ TEST_P(CertificateRequestTest, DISABLED_NonEmptyRequest_prodMode) {
		DeviceInfo deviceInfo;
		ProtectedData protectedData;
		auto status = provisionable_->generateCertificateRequest(
		testMode, keysToSign_, getProdEekChain(), challenge_, &deviceInfo, &protectedData,
		&keysToSignMac);
		testMode, keysToSign_, getProdEekChain(rpcHardwareInfo.supportedEekCurve), challenge_,
		&deviceInfo, &protectedData, &keysToSignMac);
		EXPECT_TRUE(status.isOk());
		}

		@@ -570,6 +582,7 @@ TEST_P(CertificateRequestTest, NonEmptyRequestCorruptMac_testMode) {
		bytevec keysToSignMac;
		DeviceInfo deviceInfo;
		ProtectedData protectedData;
		generateTestEekChain(3);
		auto status = provisionable_->generateCertificateRequest(
		testMode, {keyWithCorruptMac}, testEekChain_.chain, challenge_, &deviceInfo,
		&protectedData, &keysToSignMac);
		@@ -589,8 +602,8 @@ TEST_P(CertificateRequestTest, NonEmptyRequestCorruptMac_prodMode) {
		DeviceInfo deviceInfo;
		ProtectedData protectedData;
		auto status = provisionable_->generateCertificateRequest(
		testMode, {keyWithCorruptMac}, getProdEekChain(), challenge_, &deviceInfo,
		&protectedData, &keysToSignMac);
		testMode, {keyWithCorruptMac}, getProdEekChain(rpcHardwareInfo.supportedEekCurve),
		challenge_, &deviceInfo, &protectedData, &keysToSignMac);
		ASSERT_FALSE(status.isOk()) << status.getMessage();
		EXPECT_EQ(status.getServiceSpecificError(), BnRemotelyProvisionedComponent::STATUS_INVALID_MAC);
		}
		@@ -603,7 +616,7 @@ TEST_P(CertificateRequestTest, NonEmptyCorruptEekRequest_prodMode) {
		bool testMode = false;
		generateKeys(testMode, 4 /* numKeys */);

		auto prodEekChain = getProdEekChain();
		auto prodEekChain = getProdEekChain(rpcHardwareInfo.supportedEekCurve);
		auto [parsedChain, _, parseErr] = cppbor::parse(prodEekChain);
		ASSERT_NE(parsedChain, nullptr) << parseErr;
		ASSERT_NE(parsedChain->asArray(), nullptr);
		@@ -634,7 +647,7 @@ TEST_P(CertificateRequestTest, NonEmptyIncompleteEekRequest_prodMode) {

		// Build an EEK chain that omits the first self-signed cert.
		auto truncatedChain = cppbor::Array();
		auto [chain, _, parseErr] = cppbor::parse(getProdEekChain());
		auto [chain, _, parseErr] = cppbor::parse(getProdEekChain(rpcHardwareInfo.supportedEekCurve));
		ASSERT_TRUE(chain);
		auto eekChain = chain->asArray();
		ASSERT_NE(eekChain, nullptr);
		@@ -662,6 +675,7 @@ TEST_P(CertificateRequestTest, NonEmptyRequest_prodKeyInTestCert) {
		bytevec keysToSignMac;
		DeviceInfo deviceInfo;
		ProtectedData protectedData;
		generateTestEekChain(3);
		auto status = provisionable_->generateCertificateRequest(
		true /* testMode */, keysToSign_, testEekChain_.chain, challenge_, &deviceInfo,
		&protectedData, &keysToSignMac);
		@@ -680,6 +694,7 @@ TEST_P(CertificateRequestTest, NonEmptyRequest_testKeyInProdCert) {
		bytevec keysToSignMac;
		DeviceInfo deviceInfo;
		ProtectedData protectedData;
		generateTestEekChain(3);
		auto status = provisionable_->generateCertificateRequest(
		false /* testMode */, keysToSign_, testEekChain_.chain, challenge_, &deviceInfo,
		&protectedData, &keysToSignMac);

security/keymint/support/Android.bp

+7 −0

Original line number	Diff line number	Diff line
		@@ -60,11 +60,15 @@ cc_library {
		export_include_dirs: [
		"include",
		],
		defaults: [
		"keymint_use_latest_hal_aidl_ndk_shared",
		],
		shared_libs: [
		"libbase",
		"libcppbor_external",
		"libcppcose_rkp",
		"libcrypto",
		"libkeymaster_portable",
		"libjsoncpp",
		],
		}
		@@ -76,6 +80,9 @@ cc_test {
		"libgmock",
		"libgtest_main",
		],
		defaults: [
		"keymint_use_latest_hal_aidl_ndk_shared",
		],
		shared_libs: [
		"libbase",
		"libcppbor_external",

security/keymint/support/include/remote_prov/remote_prov_utils.h

+32 −4

Original line number	Diff line number	Diff line
		@@ -52,6 +52,34 @@ inline constexpr uint8_t kCoseEncodedGeekCert[] = {
		0x31, 0xbf, 0x6b, 0xe8, 0x1e, 0x35, 0xe2, 0xf0, 0x2d, 0xce, 0x6c, 0x2f, 0x4f, 0xf2,
		0xf5, 0x4f, 0xa5, 0xd4, 0x83, 0xad, 0x96, 0xa2, 0xf1, 0x87, 0x58, 0x04};

		// The Google ECDSA P256 root key for the Endpoint Encryption Key chain, encoded as COSE_Sign1
		inline constexpr uint8_t kCoseEncodedEcdsa256RootCert[] = {
		0x84, 0x43, 0xa1, 0x01, 0x26, 0xa0, 0x58, 0x4d, 0xa5, 0x01, 0x02, 0x03, 0x26, 0x20, 0x01, 0x21,
		0x58, 0x20, 0xf7, 0x14, 0x8a, 0xdb, 0x97, 0xf4, 0xcc, 0x53, 0xef, 0xd2, 0x64, 0x11, 0xc4, 0xe3,
		0x75, 0x1f, 0x66, 0x1f, 0xa4, 0x71, 0x0c, 0x6c, 0xcf, 0xfa, 0x09, 0x46, 0x80, 0x74, 0x87, 0x54,
		0xf2, 0xad, 0x22, 0x58, 0x20, 0x5e, 0x7f, 0x5b, 0xf6, 0xec, 0xe4, 0xf6, 0x19, 0xcc, 0xff, 0x13,
		0x37, 0xfd, 0x0f, 0xa1, 0xc8, 0x93, 0xdb, 0x18, 0x06, 0x76, 0xc4, 0x5d, 0xe6, 0xd7, 0x6a, 0x77,
		0x86, 0xc3, 0x2d, 0xaf, 0x8f, 0x58, 0x40, 0x2f, 0x97, 0x8e, 0x42, 0xfb, 0xbe, 0x07, 0x2d, 0x95,
		0x47, 0x85, 0x47, 0x93, 0x40, 0xb0, 0x1f, 0xd4, 0x9b, 0x47, 0xa4, 0xc4, 0x44, 0xa9, 0xf2, 0xa1,
		0x07, 0x87, 0x10, 0xc7, 0x9f, 0xcb, 0x11, 0xf4, 0xbf, 0x9f, 0xe8, 0x3b, 0xe0, 0xe7, 0x34, 0x4c,
		0x15, 0xfc, 0x7b, 0xc3, 0x7e, 0x33, 0x05, 0xf4, 0xd1, 0x34, 0x3c, 0xed, 0x02, 0x04, 0x60, 0x7a,
		0x15, 0xe0, 0x79, 0xd3, 0x8a, 0xff, 0x24};

		// The Google ECDSA P256 Endpoint Encryption Key certificate, encoded as COSE_Sign1
		inline constexpr uint8_t kCoseEncodedEcdsa256GeekCert[] = {
		0x84, 0x43, 0xa1, 0x01, 0x26, 0xa0, 0x58, 0x71, 0xa6, 0x01, 0x02, 0x02, 0x58, 0x20, 0x35, 0x73,
		0xb7, 0x3f, 0xa0, 0x8a, 0x80, 0x89, 0xb1, 0x26, 0x67, 0xe9, 0xcb, 0x7c, 0x75, 0xa1, 0xaf, 0x02,
		0x61, 0xfc, 0x6e, 0x65, 0x03, 0x91, 0x3b, 0xd3, 0x4b, 0x7d, 0x14, 0x94, 0x3e, 0x46, 0x03, 0x38,
		0x18, 0x20, 0x01, 0x21, 0x58, 0x20, 0xe0, 0x41, 0xcf, 0x2f, 0x0f, 0x34, 0x0f, 0x1c, 0x33, 0x2c,
		0x41, 0xb0, 0xcf, 0xd7, 0x0c, 0x30, 0x55, 0x35, 0xd2, 0x1e, 0x6a, 0x47, 0x13, 0x4b, 0x2e, 0xd1,
		0x48, 0x96, 0x7e, 0x24, 0x9c, 0x68, 0x22, 0x58, 0x20, 0x1f, 0xce, 0x45, 0xc5, 0xfb, 0x61, 0xba,
		0x81, 0x21, 0xf9, 0xe5, 0x05, 0x9b, 0x9b, 0x39, 0x0e, 0x76, 0x86, 0x86, 0x47, 0xb8, 0x1e, 0x2f,
		0x45, 0xf1, 0xce, 0xaf, 0xda, 0x3f, 0x80, 0x68, 0xdb, 0x58, 0x40, 0x8c, 0xb3, 0xba, 0x7e, 0x20,
		0x3e, 0x32, 0xb0, 0x68, 0xdf, 0x60, 0xd1, 0x1d, 0x7d, 0xf0, 0xac, 0x38, 0x8e, 0x51, 0xbc, 0xff,
		0x6c, 0xe1, 0x67, 0x3b, 0x4a, 0x79, 0xbc, 0x56, 0x78, 0xb3, 0x99, 0xd8, 0x7c, 0x8a, 0x07, 0xd8,
		0xda, 0xb5, 0xb5, 0x7f, 0x71, 0xf4, 0xd8, 0x6b, 0xdf, 0x33, 0x27, 0x34, 0x7b, 0x65, 0xd1, 0x2a,
		0xeb, 0x86, 0x99, 0x98, 0xab, 0x3a, 0xb4, 0x80, 0xaa, 0xbd, 0x50};

		/**
		* Generates random bytes.
		*/
		@@ -64,15 +92,15 @@ struct EekChain {
		};

		/**
		* Generates an X25518 EEK with the specified eekId and an Ed25519 chain of the
		* specified length. All keys are generated randomly.
		* Based on the supportedEekCurve, Generates an X25519/ECDH with the specified eekId
		* and an Ed25519/ECDSA chain of the specified length. All keys are generated randomly.
		*/
		ErrMsgOr<EekChain> generateEekChain(size_t length, const bytevec& eekId);
		ErrMsgOr<EekChain> generateEekChain(int32_t supportedEekCurve, size_t length, const bytevec& eekId);

		/**
		* Returns the CBOR-encoded, production Google Endpoint Encryption Key chain.
		*/
		bytevec getProdEekChain();
		bytevec getProdEekChain(int32_t supportedEekCurve);

		struct BccEntryData {
		bytevec pubKey;

security/keymint/support/remote_prov_utils.cpp

+247 −46

Original line number	Diff line number	Diff line
		@@ -17,10 +17,16 @@
		#include <iterator>
		#include <tuple>

		#include <aidl/android/hardware/security/keymint/RpcHardwareInfo.h>
		#include <android-base/properties.h>
		#include <cppbor.h>
		#include <json/json.h>
		#include <keymaster/km_openssl/ec_key.h>
		#include <keymaster/km_openssl/ecdsa_operation.h>
		#include <keymaster/km_openssl/openssl_err.h>
		#include <keymaster/km_openssl/openssl_utils.h>
		#include <openssl/base64.h>
		#include <openssl/evp.h>
		#include <openssl/rand.h>
		#include <remote_prov/remote_prov_utils.h>

		@@ -30,6 +36,166 @@ constexpr uint32_t kBccPayloadIssuer = 1;
		constexpr uint32_t kBccPayloadSubject = 2;
		constexpr int32_t kBccPayloadSubjPubKey = -4670552;
		constexpr int32_t kBccPayloadKeyUsage = -4670553;
		constexpr int kP256AffinePointSize = 32;

		using EC_KEY_Ptr = bssl::UniquePtr<EC_KEY>;
		using EVP_PKEY_Ptr = bssl::UniquePtr<EVP_PKEY>;
		using EVP_PKEY_CTX_Ptr = bssl::UniquePtr<EVP_PKEY_CTX>;

		ErrMsgOr<bytevec> ecKeyGetPrivateKey(const EC_KEY* ecKey) {
		// Extract private key.
		const BIGNUM* bignum = EC_KEY_get0_private_key(ecKey);
		if (bignum == nullptr) {
		return "Error getting bignum from private key";
		}
		// Pad with zeros in case the length is lesser than 32.
		bytevec privKey(32, 0);
		BN_bn2binpad(bignum, privKey.data(), privKey.size());
		return privKey;
		}

		ErrMsgOr<bytevec> ecKeyGetPublicKey(const EC_KEY* ecKey) {
		// Extract public key.
		auto group = EC_GROUP_Ptr(EC_GROUP_new_by_curve_name(NID_X9_62_prime256v1));
		if (group.get() == nullptr) {
		return "Error creating EC group by curve name";
		}
		const EC_POINT* point = EC_KEY_get0_public_key(ecKey);
		if (point == nullptr) return "Error getting ecpoint from public key";

		int size =
		EC_POINT_point2oct(group.get(), point, POINT_CONVERSION_UNCOMPRESSED, nullptr, 0, nullptr);
		if (size == 0) {
		return "Error generating public key encoding";
		}

		bytevec publicKey;
		publicKey.resize(size);
		EC_POINT_point2oct(group.get(), point, POINT_CONVERSION_UNCOMPRESSED, publicKey.data(),
		publicKey.size(), nullptr);
		return publicKey;
		}

		ErrMsgOr<std::tuple<bytevec, bytevec>> getAffineCoordinates(const bytevec& pubKey) {
		auto group = EC_GROUP_Ptr(EC_GROUP_new_by_curve_name(NID_X9_62_prime256v1));
		if (group.get() == nullptr) {
		return "Error creating EC group by curve name";
		}
		auto point = EC_POINT_Ptr(EC_POINT_new(group.get()));
		if (EC_POINT_oct2point(group.get(), point.get(), pubKey.data(), pubKey.size(), nullptr) != 1) {
		return "Error decoding publicKey";
		}
		BIGNUM_Ptr x(BN_new());
		BIGNUM_Ptr y(BN_new());
		BN_CTX_Ptr ctx(BN_CTX_new());
		if (!ctx.get()) return "Failed to create BN_CTX instance";

		if (!EC_POINT_get_affine_coordinates_GFp(group.get(), point.get(), x.get(), y.get(),
		ctx.get())) {
		return "Failed to get affine coordinates from ECPoint";
		}
		bytevec pubX(kP256AffinePointSize);
		bytevec pubY(kP256AffinePointSize);
		if (BN_bn2binpad(x.get(), pubX.data(), kP256AffinePointSize) != kP256AffinePointSize) {
		return "Error in converting absolute value of x coordinate to big-endian";
		}
		if (BN_bn2binpad(y.get(), pubY.data(), kP256AffinePointSize) != kP256AffinePointSize) {
		return "Error in converting absolute value of y coordinate to big-endian";
		}
		return std::make_tuple(std::move(pubX), std::move(pubY));
		}

		ErrMsgOr<std::tuple<bytevec, bytevec>> generateEc256KeyPair() {
		auto ec_key = EC_KEY_Ptr(EC_KEY_new());
		if (ec_key.get() == nullptr) {
		return "Failed to allocate ec key";
		}

		auto group = EC_GROUP_Ptr(EC_GROUP_new_by_curve_name(NID_X9_62_prime256v1));
		if (group.get() == nullptr) {
		return "Error creating EC group by curve name";
		}

		if (EC_KEY_set_group(ec_key.get(), group.get()) != 1 \|\|
		EC_KEY_generate_key(ec_key.get()) != 1 \|\| EC_KEY_check_key(ec_key.get()) < 0) {
		return "Error generating key";
		}

		auto privKey = ecKeyGetPrivateKey(ec_key.get());
		if (!privKey) return privKey.moveMessage();

		auto pubKey = ecKeyGetPublicKey(ec_key.get());
		if (!pubKey) return pubKey.moveMessage();

		return std::make_tuple(pubKey.moveValue(), privKey.moveValue());
		}

		ErrMsgOr<std::tuple<bytevec, bytevec>> generateX25519KeyPair() {
		/* Generate X25519 key pair */
		bytevec pubKey(X25519_PUBLIC_VALUE_LEN);
		bytevec privKey(X25519_PRIVATE_KEY_LEN);
		X25519_keypair(pubKey.data(), privKey.data());
		return std::make_tuple(std::move(pubKey), std::move(privKey));
		}

		ErrMsgOr<std::tuple<bytevec, bytevec>> generateED25519KeyPair() {
		/* Generate ED25519 key pair */
		bytevec pubKey(ED25519_PUBLIC_KEY_LEN);
		bytevec privKey(ED25519_PRIVATE_KEY_LEN);
		ED25519_keypair(pubKey.data(), privKey.data());
		return std::make_tuple(std::move(pubKey), std::move(privKey));
		}

		ErrMsgOr<std::tuple<bytevec, bytevec>> generateKeyPair(int32_t supportedEekCurve, bool isEek) {
		switch (supportedEekCurve) {
		case RpcHardwareInfo::CURVE_25519:
		if (isEek) {
		return generateX25519KeyPair();
		}
		return generateED25519KeyPair();
		case RpcHardwareInfo::CURVE_P256:
		return generateEc256KeyPair();
		default:
		return "Unknown EEK Curve.";
		}
		}

		ErrMsgOr<bytevec> constructCoseKey(int32_t supportedEekCurve, const bytevec& eekId,
		const bytevec& pubKey) {
		CoseKeyType keyType;
		CoseKeyAlgorithm algorithm;
		CoseKeyCurve curve;
		bytevec pubX;
		bytevec pubY;
		switch (supportedEekCurve) {
		case RpcHardwareInfo::CURVE_25519:
		keyType = OCTET_KEY_PAIR;
		algorithm = (eekId.empty()) ? EDDSA : ECDH_ES_HKDF_256;
		curve = (eekId.empty()) ? ED25519 : cppcose::X25519;
		pubX = pubKey;
		break;
		case RpcHardwareInfo::CURVE_P256: {
		keyType = EC2;
		algorithm = (eekId.empty()) ? ES256 : ECDH_ES_HKDF_256;
		curve = P256;
		auto affineCoordinates = getAffineCoordinates(pubKey);
		if (!affineCoordinates) return affineCoordinates.moveMessage();
		std::tie(pubX, pubY) = affineCoordinates.moveValue();
		} break;
		default:
		return "Unknown EEK Curve.";
		}
		cppbor::Map coseKey = cppbor::Map()
		.add(CoseKey::KEY_TYPE, keyType)
		.add(CoseKey::ALGORITHM, algorithm)
		.add(CoseKey::CURVE, curve)
		.add(CoseKey::PUBKEY_X, pubX);

		if (!pubY.empty()) coseKey.add(CoseKey::PUBKEY_Y, pubY);
		if (!eekId.empty()) coseKey.add(CoseKey::KEY_ID, eekId);

		return coseKey.canonicalize().encode();
		}

		bytevec kTestMacKey(32 /* count /, 0 / byte value */);

		@@ -39,7 +205,17 @@ bytevec randomBytes(size_t numBytes) {
		return retval;
		}

		ErrMsgOr<EekChain> generateEekChain(size_t length, const bytevec& eekId) {
		ErrMsgOr<cppbor::Array> constructCoseSign1(int32_t supportedEekCurve, const bytevec& key,
		const bytevec& payload, const bytevec& aad) {
		if (supportedEekCurve == RpcHardwareInfo::CURVE_P256) {
		return constructECDSACoseSign1(key, {} /* protectedParams */, payload, aad);
		} else {
		return cppcose::constructCoseSign1(key, payload, aad);
		}
		}

		ErrMsgOr<EekChain> generateEekChain(int32_t supportedEekCurve, size_t length,
		const bytevec& eekId) {
		if (length < 2) {
		return "EEK chain must contain at least 2 certs.";
		}
		@@ -48,59 +224,62 @@ ErrMsgOr<EekChain> generateEekChain(size_t length, const bytevec& eekId) {

		bytevec prev_priv_key;
		for (size_t i = 0; i < length - 1; ++i) {
		bytevec pub_key(ED25519_PUBLIC_KEY_LEN);
		bytevec priv_key(ED25519_PRIVATE_KEY_LEN);

		ED25519_keypair(pub_key.data(), priv_key.data());
		auto keyPair = generateKeyPair(supportedEekCurve, false);
		if (!keyPair) keyPair.moveMessage();
		auto [pub_key, priv_key] = keyPair.moveValue();

		// The first signing key is self-signed.
		if (prev_priv_key.empty()) prev_priv_key = priv_key;

		auto coseSign1 = constructCoseSign1(prev_priv_key,
		cppbor::Map() /* payload CoseKey */
		.add(CoseKey::KEY_TYPE, OCTET_KEY_PAIR)
		.add(CoseKey::ALGORITHM, EDDSA)
		.add(CoseKey::CURVE, ED25519)
		.add(CoseKey::PUBKEY_X, pub_key)
		.canonicalize()
		.encode(),
		{} /* AAD */);
		auto coseKey = constructCoseKey(supportedEekCurve, {}, pub_key);
		if (!coseKey) return coseKey.moveMessage();

		auto coseSign1 =
		constructCoseSign1(supportedEekCurve, prev_priv_key, coseKey.moveValue(), {} /* AAD */);
		if (!coseSign1) return coseSign1.moveMessage();
		eekChain.add(coseSign1.moveValue());

		prev_priv_key = priv_key;
		}
		auto keyPair = generateKeyPair(supportedEekCurve, true);
		if (!keyPair) keyPair.moveMessage();
		auto [pub_key, priv_key] = keyPair.moveValue();

		bytevec pub_key(X25519_PUBLIC_VALUE_LEN);
		bytevec priv_key(X25519_PRIVATE_KEY_LEN);
		X25519_keypair(pub_key.data(), priv_key.data());

		auto coseSign1 = constructCoseSign1(prev_priv_key,
		cppbor::Map() /* payload CoseKey */
		.add(CoseKey::KEY_TYPE, OCTET_KEY_PAIR)
		.add(CoseKey::KEY_ID, eekId)
		.add(CoseKey::ALGORITHM, ECDH_ES_HKDF_256)
		.add(CoseKey::CURVE, cppcose::X25519)
		.add(CoseKey::PUBKEY_X, pub_key)
		.canonicalize()
		.encode(),
		{} /* AAD */);
		auto coseKey = constructCoseKey(supportedEekCurve, eekId, pub_key);
		if (!coseKey) return coseKey.moveMessage();

		auto coseSign1 =
		constructCoseSign1(supportedEekCurve, prev_priv_key, coseKey.moveValue(), {} /* AAD */);
		if (!coseSign1) return coseSign1.moveMessage();
		eekChain.add(coseSign1.moveValue());

		return EekChain{eekChain.encode(), pub_key, priv_key};
		if (supportedEekCurve == RpcHardwareInfo::CURVE_P256) {
		// convert ec public key to x and y co-ordinates.
		auto affineCoordinates = getAffineCoordinates(pub_key);
		if (!affineCoordinates) return affineCoordinates.moveMessage();
		auto [pubX, pubY] = affineCoordinates.moveValue();
		pub_key.clear();
		pub_key.insert(pub_key.begin(), pubX.begin(), pubX.end());
		pub_key.insert(pub_key.end(), pubY.begin(), pubY.end());
		}

		bytevec getProdEekChain() {
		bytevec prodEek;
		prodEek.reserve(1 + sizeof(kCoseEncodedRootCert) + sizeof(kCoseEncodedGeekCert));

		// In CBOR encoding, 0x82 indicates an array of two items
		prodEek.push_back(0x82);
		prodEek.insert(prodEek.end(), std::begin(kCoseEncodedRootCert), std::end(kCoseEncodedRootCert));
		prodEek.insert(prodEek.end(), std::begin(kCoseEncodedGeekCert), std::end(kCoseEncodedGeekCert));
		return EekChain{eekChain.encode(), pub_key, priv_key};
		}

		return prodEek;
		bytevec getProdEekChain(int32_t supportedEekCurve) {
		cppbor::Array chain;
		if (supportedEekCurve == RpcHardwareInfo::CURVE_P256) {
		chain.add(cppbor::EncodedItem(bytevec(std::begin(kCoseEncodedEcdsa256RootCert),
		std::end(kCoseEncodedEcdsa256RootCert))));
		chain.add(cppbor::EncodedItem(bytevec(std::begin(kCoseEncodedEcdsa256GeekCert),
		std::end(kCoseEncodedEcdsa256GeekCert))));
		} else {
		chain.add(cppbor::EncodedItem(
		bytevec(std::begin(kCoseEncodedRootCert), std::end(kCoseEncodedRootCert))));
		chain.add(cppbor::EncodedItem(
		bytevec(std::begin(kCoseEncodedGeekCert), std::end(kCoseEncodedGeekCert))));
		}
		return chain.encode();
		}

		ErrMsgOr<bytevec> validatePayloadAndFetchPubKey(const cppbor::Map* payload) {
		@@ -139,7 +318,8 @@ ErrMsgOr<bytevec> verifyAndParseCoseSign1Cwt(const cppbor::Array* coseSign1,
		}

		auto& algorithm = parsedProtParams->asMap()->get(ALGORITHM);
		if (!algorithm \|\| !algorithm->asInt() \|\| algorithm->asInt()->value() != EDDSA) {
		if (!algorithm \|\| !algorithm->asInt() \|\|
		(algorithm->asInt()->value() != EDDSA && algorithm->asInt()->value() != ES256)) {
		return "Unsupported signature algorithm";
		}

		@@ -152,16 +332,37 @@ ErrMsgOr<bytevec> verifyAndParseCoseSign1Cwt(const cppbor::Array* coseSign1,
		}

		bool selfSigned = signingCoseKey.empty();
		auto key = CoseKey::parseEd25519(selfSigned ? *serializedKey : signingCoseKey);
		if (!key) return "Bad signing key: " + key.moveMessage();

		bytevec signatureInput =
		cppbor::Array().add("Signature1").add(protectedParams).add(aad).add(payload).encode();

		if (algorithm->asInt()->value() == EDDSA) {
		auto key = CoseKey::parseEd25519(selfSigned ? *serializedKey : signingCoseKey);

		if (!key) return "Bad signing key: " + key.moveMessage();

		if (!ED25519_verify(signatureInput.data(), signatureInput.size(), signature->value().data(),
		key->getBstrValue(CoseKey::PUBKEY_X)->data())) {
		return "Signature verification failed";
		}
		} else { // P256
		auto key = CoseKey::parseP256(selfSigned ? *serializedKey : signingCoseKey);
		if (!key \|\| key->getBstrValue(CoseKey::PUBKEY_X)->empty() \|\|
		key->getBstrValue(CoseKey::PUBKEY_Y)->empty()) {
		return "Bad signing key: " + key.moveMessage();
		}
		auto publicKey = key->getEcPublicKey();
		if (!publicKey) return publicKey.moveMessage();

		auto ecdsaDerSignature = ecdsaCoseSignatureToDer(signature->value());
		if (!ecdsaDerSignature) return ecdsaDerSignature.moveMessage();

		// convert public key to uncompressed form.
		publicKey->insert(publicKey->begin(), 0x04);

		if (!verifyEcdsaDigest(publicKey.moveValue(), sha256(signatureInput), *ecdsaDerSignature)) {
		return "Signature verification failed";
		}
		}

		return serializedKey.moveValue();
		}

security/keymint/support/remote_prov_utils_test.cpp

+158 −7

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