Support for P256 curve in RKP for Strongbox

Test: Run Rkp Vts tests.

Change-Id: Ic38fd2318dd8749ae125f1e78d25f2722bd367e5

1 files changed, 158 insertions, 7 deletions

diff --git a/security/keymint/support/remote_prov_utils_test.cpp b/security/keymint/support/remote_prov_utils_test.cpp
index 8697c5190f..e1c4467a64 100644
--- a/security/keymint/support/remote_prov_utils_test.cpp
+++ b/security/keymint/support/remote_prov_utils_test.cpp
@@ -14,8 +14,12 @@
  * limitations under the License.
  */
 
+#include "cppbor.h"
+#include "keymaster/cppcose/cppcose.h"
+#include <aidl/android/hardware/security/keymint/RpcHardwareInfo.h>
 #include <android-base/properties.h>
 #include <cppbor_parse.h>
+#include <cstdint>
 #include <gmock/gmock.h>
 #include <gtest/gtest.h>
 #include <keymaster/android_keymaster_utils.h>
@@ -23,25 +27,120 @@
 #include <keymaster/remote_provisioning_utils.h>
 #include <openssl/curve25519.h>
 #include <remote_prov/remote_prov_utils.h>
-#include <cstdint>
-#include "cppbor.h"
-#include "keymaster/cppcose/cppcose.h"
 
 namespace aidl::android::hardware::security::keymint::remote_prov {
 namespace {
 
 using ::keymaster::KeymasterBlob;
-using ::keymaster::validateAndExtractEekPubAndId;
+using ::keymaster::kStatusFailed;
+using ::keymaster::kStatusInvalidEek;
+using ::keymaster::StatusOr;
 using ::testing::ElementsAreArray;
+using byte_view = std::basic_string_view<uint8_t>;
+
+struct KeyInfoEcdsa {
+    CoseKeyCurve curve;
+    byte_view pubKeyX;
+    byte_view pubKeyY;
+
+    bool operator==(const KeyInfoEcdsa& other) const {
+        return curve == other.curve && pubKeyX == other.pubKeyX && pubKeyY == other.pubKeyY;
+    }
+};
+
+// The production root signing key for Google ECDSA P256 Endpoint Encryption Key cert chains.
+inline constexpr uint8_t kEcdsa256GeekRootX[] = {
+    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};
+
+inline constexpr uint8_t kEcdsa256GeekRootY[] = {
+    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};
+
+// Hard-coded set of acceptable public COSE_Keys that can act as roots of EEK chains.
+inline constexpr KeyInfoEcdsa kAuthorizedEcdsa256EekRoots[] = {
+    {CoseKeyCurve::P256, byte_view(kEcdsa256GeekRootX, sizeof(kEcdsa256GeekRootX)),
+     byte_view(kEcdsa256GeekRootY, sizeof(kEcdsa256GeekRootY))},
+};
+
+static ErrMsgOr<CoseKey> parseEcdh256(const bytevec& coseKey) {
+    auto key = CoseKey::parse(coseKey, EC2, ECDH_ES_HKDF_256, P256);
+    if (!key) return key;
+
+    auto& pubkey_x = key->getMap().get(cppcose::CoseKey::PUBKEY_X);
+    auto& pubkey_y = key->getMap().get(cppcose::CoseKey::PUBKEY_Y);
+    if (!pubkey_x || !pubkey_y || !pubkey_x->asBstr() || !pubkey_y->asBstr() ||
+        pubkey_x->asBstr()->value().size() != 32 || pubkey_y->asBstr()->value().size() != 32) {
+        return "Invalid P256 public key";
+    }
+
+    return key;
+}
+
+StatusOr<std::tuple<std::vector<uint8_t> /* EEK pubX */, std::vector<uint8_t> /* EEK pubY */,
+                    std::vector<uint8_t> /* EEK ID */>>
+validateAndExtractEcdsa256EekPubAndId(bool testMode,
+                                      const KeymasterBlob& endpointEncryptionCertChain) {
+    auto [item, newPos, errMsg] =
+        cppbor::parse(endpointEncryptionCertChain.begin(), endpointEncryptionCertChain.end());
+    if (!item || !item->asArray()) {
+        return kStatusFailed;
+    }
+    const cppbor::Array* certArr = item->asArray();
+    std::vector<uint8_t> lastPubKey;
+    for (size_t i = 0; i < certArr->size(); ++i) {
+        auto cosePubKey =
+            verifyAndParseCoseSign1(certArr->get(i)->asArray(), lastPubKey, {} /* AAD */);
+        if (!cosePubKey) {
+            return kStatusInvalidEek;
+        }
+        lastPubKey = *std::move(cosePubKey);
+
+        // In prod mode the first pubkey should match a well-known Google public key.
+        if (!testMode && i == 0) {
+            auto parsedPubKey = CoseKey::parse(lastPubKey);
+            if (!parsedPubKey) {
+                return kStatusFailed;
+            }
+            auto curve = parsedPubKey->getIntValue(CoseKey::CURVE);
+            if (!curve) {
+                return kStatusInvalidEek;
+            }
+            auto rawPubX = parsedPubKey->getBstrValue(CoseKey::PUBKEY_X);
+            if (!rawPubX) {
+                return kStatusInvalidEek;
+            }
+            auto rawPubY = parsedPubKey->getBstrValue(CoseKey::PUBKEY_Y);
+            if (!rawPubY) {
+                return kStatusInvalidEek;
+            }
+            KeyInfoEcdsa matcher = {static_cast<CoseKeyCurve>(*curve),
+                                    byte_view(rawPubX->data(), rawPubX->size()),
+                                    byte_view(rawPubY->data(), rawPubY->size())};
+            if (std::find(std::begin(kAuthorizedEcdsa256EekRoots),
+                          std::end(kAuthorizedEcdsa256EekRoots),
+                          matcher) == std::end(kAuthorizedEcdsa256EekRoots)) {
+                return kStatusInvalidEek;
+            }
+        }
+    }
+    auto eek = parseEcdh256(lastPubKey);
+    if (!eek) {
+        return kStatusInvalidEek;
+    }
+    return std::make_tuple(eek->getBstrValue(CoseKey::PUBKEY_X).value(),
+                           eek->getBstrValue(CoseKey::PUBKEY_Y).value(),
+                           eek->getBstrValue(CoseKey::KEY_ID).value());
+}
 
 TEST(RemoteProvUtilsTest, GenerateEekChainInvalidLength) {
-    ASSERT_FALSE(generateEekChain(1, /*eekId=*/{}));
+    ASSERT_FALSE(generateEekChain(RpcHardwareInfo::CURVE_25519, 1, /*eekId=*/{}));
 }
 
 TEST(RemoteProvUtilsTest, GenerateEekChain) {
     bytevec kTestEekId = {'t', 'e', 's', 't', 'I', 'd', 0};
     for (size_t length : {2, 3, 31}) {
-        auto get_eek_result = generateEekChain(length, kTestEekId);
+        auto get_eek_result = generateEekChain(RpcHardwareInfo::CURVE_25519, length, kTestEekId);
         ASSERT_TRUE(get_eek_result) << get_eek_result.message();
 
         auto& [chain, pubkey, privkey] = *get_eek_result;
@@ -57,7 +156,7 @@ TEST(RemoteProvUtilsTest, GenerateEekChain) {
 }
 
 TEST(RemoteProvUtilsTest, GetProdEekChain) {
-    auto chain = getProdEekChain();
+    auto chain = getProdEekChain(RpcHardwareInfo::CURVE_25519);
 
     auto validation_result = validateAndExtractEekPubAndId(
             /*testMode=*/false, KeymasterBlob(chain.data(), chain.size()));
@@ -97,5 +196,57 @@ TEST(RemoteProvUtilsTest, JsonEncodeCsr) {
     ASSERT_EQ(json, expected);
 }
 
+TEST(RemoteProvUtilsTest, GenerateEcdsaEekChainInvalidLength) {
+    ASSERT_FALSE(generateEekChain(RpcHardwareInfo::CURVE_P256, 1, /*eekId=*/{}));
+}
+
+TEST(RemoteProvUtilsTest, GenerateEcdsaEekChain) {
+    bytevec kTestEekId = {'t', 'e', 's', 't', 'I', 'd', 0};
+    for (size_t length : {2, 3, 31}) {
+        auto get_eek_result = generateEekChain(RpcHardwareInfo::CURVE_P256, length, kTestEekId);
+        ASSERT_TRUE(get_eek_result) << get_eek_result.message();
+
+        auto& [chain, pubkey, privkey] = *get_eek_result;
+
+        auto validation_result = validateAndExtractEcdsa256EekPubAndId(
+            /*testMode=*/true, KeymasterBlob(chain.data(), chain.size()));
+        ASSERT_TRUE(validation_result.isOk());
+
+        auto& [eekPubX, eekPubY, eekId] = *validation_result;
+        bytevec eekPub;
+        eekPub.insert(eekPub.begin(), eekPubX.begin(), eekPubX.end());
+        eekPub.insert(eekPub.end(), eekPubY.begin(), eekPubY.end());
+        EXPECT_THAT(eekId, ElementsAreArray(kTestEekId));
+        EXPECT_THAT(eekPub, ElementsAreArray(pubkey));
+    }
+}
+
+TEST(RemoteProvUtilsTest, GetProdEcdsaEekChain) {
+    auto chain = getProdEekChain(RpcHardwareInfo::CURVE_P256);
+
+    auto validation_result = validateAndExtractEcdsa256EekPubAndId(
+        /*testMode=*/false, KeymasterBlob(chain.data(), chain.size()));
+    ASSERT_TRUE(validation_result.isOk()) << "Error: " << validation_result.moveError();
+
+    auto& [eekPubX, eekPubY, eekId] = *validation_result;
+
+    auto [geekCert, ignoredNewPos, error] =
+        cppbor::parse(kCoseEncodedEcdsa256GeekCert, sizeof(kCoseEncodedEcdsa256GeekCert));
+    ASSERT_NE(geekCert, nullptr) << "Error: " << error;
+    ASSERT_NE(geekCert->asArray(), nullptr);
+
+    auto& encodedGeekCoseKey = geekCert->asArray()->get(kCoseSign1Payload);
+    ASSERT_NE(encodedGeekCoseKey, nullptr);
+    ASSERT_NE(encodedGeekCoseKey->asBstr(), nullptr);
+
+    auto geek = CoseKey::parse(encodedGeekCoseKey->asBstr()->value());
+    ASSERT_TRUE(geek) << "Error: " << geek.message();
+
+    const std::vector<uint8_t> empty;
+    EXPECT_THAT(eekId, ElementsAreArray(geek->getBstrValue(CoseKey::KEY_ID).value_or(empty)));
+    EXPECT_THAT(eekPubX, ElementsAreArray(geek->getBstrValue(CoseKey::PUBKEY_X).value_or(empty)));
+    EXPECT_THAT(eekPubY, ElementsAreArray(geek->getBstrValue(CoseKey::PUBKEY_Y).value_or(empty)));
+}
+
 }  // namespace
 }  // namespace aidl::android::hardware::security::keymint::remote_prov