Merge "Implement alternate SE RoT provisioning"

security/keymint/aidl/android/hardware/security/keymint/IKeyMintDevice.aidl

@@ -873,7 +873,7 @@ interface IKeyMintDevice {
      * The returned data is an encoded COSE_Mac0 structure, denoted MacedRootOfTrust in the
      * following CDDL schema.  Note that K_mac is the shared HMAC key used for auth tokens, etc.:
      *
-     *     MacedRootOfTrust = [               ; COSE_Mac0 (untagged)
+     *     MacedRootOfTrust = #6.17 [         ; COSE_Mac0 (tagged)
      *         protected: bstr .cbor {
      *             1 : 5,                     ; Algorithm : HMAC-256
      *         },
@@ -891,7 +891,7 @@ interface IKeyMintDevice {
      *         payload : bstr .cbor RootOfTrust,
      *     ]
      *
-     *     RootOfTrust = [
+     *     RootOfTrust = #6.40001 [           ; Tag 40001 indicates RoT v1.
      *         verifiedBootKey : bstr .size 32,
      *         deviceLocked : bool,
      *         verifiedBootState : &VerifiedBootState,

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

@@ -31,7 +31,6 @@
 #include <remote_prov/remote_prov_utils.h>
 
 #include <keymaster/cppcose/cppcose.h>
-#include <keymint_support/attestation_record.h>
 #include <keymint_support/key_param_output.h>
 #include <keymint_support/keymint_utils.h>
 #include <keymint_support/openssl_utils.h>
@@ -1497,6 +1496,60 @@ void verify_subject_and_serial(const Certificate& certificate,  //
     verify_subject(cert.get(), subject, self_signed);
 }
 
+void verify_root_of_trust(const vector<uint8_t>& verified_boot_key, bool device_locked,
+                          VerifiedBoot verified_boot_state,
+                          const vector<uint8_t>& verified_boot_hash) {
+    char property_value[PROPERTY_VALUE_MAX] = {};
+
+    if (avb_verification_enabled()) {
+        EXPECT_NE(property_get("ro.boot.vbmeta.digest", property_value, ""), 0);
+        string prop_string(property_value);
+        EXPECT_EQ(prop_string.size(), 64);
+        EXPECT_EQ(prop_string, bin2hex(verified_boot_hash));
+
+        EXPECT_NE(property_get("ro.boot.vbmeta.device_state", property_value, ""), 0);
+        if (!strcmp(property_value, "unlocked")) {
+            EXPECT_FALSE(device_locked);
+        } else {
+            EXPECT_TRUE(device_locked);
+        }
+
+        // Check that the device is locked if not debuggable, e.g., user build
+        // images in CTS. For VTS, debuggable images are used to allow adb root
+        // and the device is unlocked.
+        if (!property_get_bool("ro.debuggable", false)) {
+            EXPECT_TRUE(device_locked);
+        } else {
+            EXPECT_FALSE(device_locked);
+        }
+    }
+
+    // Verified boot key should be all 0's if the boot state is not verified or self signed
+    std::string empty_boot_key(32, '\0');
+    std::string verified_boot_key_str((const char*)verified_boot_key.data(),
+                                      verified_boot_key.size());
+    EXPECT_NE(property_get("ro.boot.verifiedbootstate", property_value, ""), 0);
+    if (!strcmp(property_value, "green")) {
+        EXPECT_EQ(verified_boot_state, VerifiedBoot::VERIFIED);
+        EXPECT_NE(0, memcmp(verified_boot_key.data(), empty_boot_key.data(),
+                            verified_boot_key.size()));
+    } else if (!strcmp(property_value, "yellow")) {
+        EXPECT_EQ(verified_boot_state, VerifiedBoot::SELF_SIGNED);
+        EXPECT_NE(0, memcmp(verified_boot_key.data(), empty_boot_key.data(),
+                            verified_boot_key.size()));
+    } else if (!strcmp(property_value, "orange")) {
+        EXPECT_EQ(verified_boot_state, VerifiedBoot::UNVERIFIED);
+        EXPECT_EQ(0, memcmp(verified_boot_key.data(), empty_boot_key.data(),
+                            verified_boot_key.size()));
+    } else if (!strcmp(property_value, "red")) {
+        EXPECT_EQ(verified_boot_state, VerifiedBoot::FAILED);
+    } else {
+        EXPECT_EQ(verified_boot_state, VerifiedBoot::UNVERIFIED);
+        EXPECT_EQ(0, memcmp(verified_boot_key.data(), empty_boot_key.data(),
+                            verified_boot_key.size()));
+    }
+}
+
 bool verify_attestation_record(int32_t aidl_version,                   //
                                const string& challenge,                //
                                const string& app_id,                   //
@@ -1551,8 +1604,6 @@ bool verify_attestation_record(int32_t aidl_version,                   //
     EXPECT_EQ(security_level, att_keymint_security_level);
     EXPECT_EQ(security_level, att_attestation_security_level);
 
-
-    char property_value[PROPERTY_VALUE_MAX] = {};
     // TODO(b/136282179): When running under VTS-on-GSI the TEE-backed
     // keymint implementation will report YYYYMM dates instead of YYYYMMDD
     // for the BOOT_PATCH_LEVEL.
@@ -1612,54 +1663,7 @@ bool verify_attestation_record(int32_t aidl_version,                   //
     error = parse_root_of_trust(attest_rec->data, attest_rec->length, &verified_boot_key,
                                 &verified_boot_state, &device_locked, &verified_boot_hash);
     EXPECT_EQ(ErrorCode::OK, error);
-
+    verify_root_of_trust(verified_boot_key, device_locked, verified_boot_state, verified_boot_hash);
-    if (avb_verification_enabled()) {
-        EXPECT_NE(property_get("ro.boot.vbmeta.digest", property_value, ""), 0);
-        string prop_string(property_value);
-        EXPECT_EQ(prop_string.size(), 64);
-        EXPECT_EQ(prop_string, bin2hex(verified_boot_hash));
-
-        EXPECT_NE(property_get("ro.boot.vbmeta.device_state", property_value, ""), 0);
-        if (!strcmp(property_value, "unlocked")) {
-            EXPECT_FALSE(device_locked);
-        } else {
-            EXPECT_TRUE(device_locked);
-        }
-
-        // Check that the device is locked if not debuggable, e.g., user build
-        // images in CTS. For VTS, debuggable images are used to allow adb root
-        // and the device is unlocked.
-        if (!property_get_bool("ro.debuggable", false)) {
-            EXPECT_TRUE(device_locked);
-        } else {
-            EXPECT_FALSE(device_locked);
-        }
-    }
-
-    // Verified boot key should be all 0's if the boot state is not verified or self signed
-    std::string empty_boot_key(32, '\0');
-    std::string verified_boot_key_str((const char*)verified_boot_key.data(),
-                                      verified_boot_key.size());
-    EXPECT_NE(property_get("ro.boot.verifiedbootstate", property_value, ""), 0);
-    if (!strcmp(property_value, "green")) {
-        EXPECT_EQ(verified_boot_state, VerifiedBoot::VERIFIED);
-        EXPECT_NE(0, memcmp(verified_boot_key.data(), empty_boot_key.data(),
-                            verified_boot_key.size()));
-    } else if (!strcmp(property_value, "yellow")) {
-        EXPECT_EQ(verified_boot_state, VerifiedBoot::SELF_SIGNED);
-        EXPECT_NE(0, memcmp(verified_boot_key.data(), empty_boot_key.data(),
-                            verified_boot_key.size()));
-    } else if (!strcmp(property_value, "orange")) {
-        EXPECT_EQ(verified_boot_state, VerifiedBoot::UNVERIFIED);
-        EXPECT_EQ(0, memcmp(verified_boot_key.data(), empty_boot_key.data(),
-                            verified_boot_key.size()));
-    } else if (!strcmp(property_value, "red")) {
-        EXPECT_EQ(verified_boot_state, VerifiedBoot::FAILED);
-    } else {
-        EXPECT_EQ(verified_boot_state, VerifiedBoot::UNVERIFIED);
-        EXPECT_EQ(0, memcmp(verified_boot_key.data(), empty_boot_key.data(),
-                            verified_boot_key.size()));
-    }
 
     att_sw_enforced.Sort();
     expected_sw_enforced.Sort();

security/keymint/aidl/vts/functional/KeyMintAidlTestBase.h

@@ -31,6 +31,7 @@
 #include <aidl/android/hardware/security/keymint/IKeyMintDevice.h>
 #include <aidl/android/hardware/security/keymint/MacedPublicKey.h>
 
+#include <keymint_support/attestation_record.h>
 #include <keymint_support/authorization_set.h>
 #include <keymint_support/openssl_utils.h>
 
@@ -363,7 +364,10 @@ void verify_serial(X509* cert, const uint64_t expected_serial);
 void verify_subject_and_serial(const Certificate& certificate,  //
                                const uint64_t expected_serial,  //
                                const string& subject, bool self_signed);
-
+void verify_root_of_trust(const vector<uint8_t>& verified_boot_key,  //
+                          bool device_locked,                        //
+                          VerifiedBoot verified_boot_state,          //
+                          const vector<uint8_t>& verified_boot_hash);
 bool verify_attestation_record(int aidl_version,                       //
                                const string& challenge,                //
                                const string& app_id,                   //

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

@@ -36,6 +36,8 @@ using std::map;
 using std::shared_ptr;
 using std::vector;
 
+constexpr int kRoTVersion1 = 40001;
+
 class SecureElementProvisioningTest : public testing::Test {
   protected:
     static void SetUpTestSuite() {
@@ -57,6 +59,83 @@ class SecureElementProvisioningTest : public testing::Test {
         }
     }
 
+    void validateMacedRootOfTrust(const vector<uint8_t>& rootOfTrust) {
+        SCOPED_TRACE(testing::Message() << "RoT: " << bin2hex(rootOfTrust));
+
+        const auto [macItem, macEndPos, macErrMsg] = cppbor::parse(rootOfTrust);
+        ASSERT_TRUE(macItem) << "Root of trust parsing failed: " << macErrMsg;
+        ASSERT_EQ(macItem->semanticTagCount(), 1);
+        ASSERT_EQ(macItem->semanticTag(0), cppcose::kCoseMac0SemanticTag);
+        ASSERT_TRUE(macItem->asArray());
+        ASSERT_EQ(macItem->asArray()->size(), cppcose::kCoseMac0EntryCount);
+
+        const auto& protectedItem = macItem->asArray()->get(cppcose::kCoseMac0ProtectedParams);
+        ASSERT_TRUE(protectedItem);
+        ASSERT_TRUE(protectedItem->asBstr());
+        const auto [protMap, protEndPos, protErrMsg] = cppbor::parse(protectedItem->asBstr());
+        ASSERT_TRUE(protMap);
+        ASSERT_TRUE(protMap->asMap());
+        ASSERT_EQ(protMap->asMap()->size(), 1);
+
+        const auto& algorithm = protMap->asMap()->get(cppcose::ALGORITHM);
+        ASSERT_TRUE(algorithm);
+        ASSERT_TRUE(algorithm->asInt());
+        ASSERT_EQ(algorithm->asInt()->value(), cppcose::HMAC_256);
+
+        const auto& unprotItem = macItem->asArray()->get(cppcose::kCoseMac0UnprotectedParams);
+        ASSERT_TRUE(unprotItem);
+        ASSERT_TRUE(unprotItem->asMap());
+        ASSERT_EQ(unprotItem->asMap()->size(), 0);
+
+        const auto& payload = macItem->asArray()->get(cppcose::kCoseMac0Payload);
+        ASSERT_TRUE(payload);
+        ASSERT_TRUE(payload->asBstr());
+        validateRootOfTrust(payload->asBstr()->value());
+
+        const auto& tag = macItem->asArray()->get(cppcose::kCoseMac0Tag);
+        ASSERT_TRUE(tag);
+        ASSERT_TRUE(tag->asBstr());
+        ASSERT_EQ(tag->asBstr()->value().size(), 32);
+        // Cannot validate tag correctness.  Only the secure side has the necessary key.
+    }
+
+    void validateRootOfTrust(const vector<uint8_t>& payload) {
+        SCOPED_TRACE(testing::Message() << "RoT payload: " << bin2hex(payload));
+
+        const auto [rot, rotPos, rotErrMsg] = cppbor::parse(payload);
+        ASSERT_TRUE(rot);
+        ASSERT_EQ(rot->semanticTagCount(), 1);
+        ASSERT_EQ(rot->semanticTag(), kRoTVersion1);
+        ASSERT_TRUE(rot->asArray());
+        ASSERT_EQ(rot->asArray()->size(), 5);
+
+        size_t pos = 0;
+
+        const auto& vbKey = rot->asArray()->get(pos++);
+        ASSERT_TRUE(vbKey);
+        ASSERT_TRUE(vbKey->asBstr());
+
+        const auto& deviceLocked = rot->asArray()->get(pos++);
+        ASSERT_TRUE(deviceLocked);
+        ASSERT_TRUE(deviceLocked->asBool());
+
+        const auto& verifiedBootState = rot->asArray()->get(pos++);
+        ASSERT_TRUE(verifiedBootState);
+        ASSERT_TRUE(verifiedBootState->asInt());
+
+        const auto& verifiedBootHash = rot->asArray()->get(pos++);
+        ASSERT_TRUE(verifiedBootHash);
+        ASSERT_TRUE(verifiedBootHash->asBstr());
+
+        const auto& bootPatchLevel = rot->asArray()->get(pos++);
+        ASSERT_TRUE(bootPatchLevel);
+        ASSERT_TRUE(bootPatchLevel->asInt());
+
+        verify_root_of_trust(vbKey->asBstr()->value(), deviceLocked->asBool()->value(),
+                             static_cast<VerifiedBoot>(verifiedBootState->asInt()->value()),
+                             verifiedBootHash->asBstr()->value());
+    }
+
     int32_t AidlVersion(shared_ptr<IKeyMintDevice> keymint) {
         int32_t version = 0;
         auto status = keymint->getInterfaceVersion(&version);
@@ -96,29 +175,19 @@ TEST_F(SecureElementProvisioningTest, TeeOnly) {
 
     vector<uint8_t> rootOfTrust1;
     Status result = tee->getRootOfTrust(challenge1, &rootOfTrust1);
-
+    ASSERT_TRUE(result.isOk()) << "getRootOfTrust returned " << result.getServiceSpecificError();
-    // TODO: Remove the next line to require TEEs to succeed.
+    validateMacedRootOfTrust(rootOfTrust1);
-    if (!result.isOk()) return;
-
-    ASSERT_TRUE(result.isOk());
-
-    // TODO:  Parse and validate rootOfTrust1 here
 
     vector<uint8_t> rootOfTrust2;
     result = tee->getRootOfTrust(challenge2, &rootOfTrust2);
     ASSERT_TRUE(result.isOk());
-
+    validateMacedRootOfTrust(rootOfTrust2);
-    // TODO:  Parse and validate rootOfTrust2 here
-
     ASSERT_NE(rootOfTrust1, rootOfTrust2);
 
     vector<uint8_t> rootOfTrust3;
     result = tee->getRootOfTrust(challenge1, &rootOfTrust3);
     ASSERT_TRUE(result.isOk());
-
     ASSERT_EQ(rootOfTrust1, rootOfTrust3);
-
-    // TODO:  Parse and validate rootOfTrust3 here
 }
 
 TEST_F(SecureElementProvisioningTest, TeeDoesNotImplementStrongBoxMethods) {
@@ -252,7 +321,7 @@ TEST_F(SecureElementProvisioningTest, ProvisioningTest) {
     result = tee->getRootOfTrust(challenge, &rootOfTrust);
     ASSERT_TRUE(result.isOk());
 
-    // TODO: Verify COSE_Mac0 structure and content here.
+    validateMacedRootOfTrust(rootOfTrust);
 
     result = sb->sendRootOfTrust(rootOfTrust);
     ASSERT_TRUE(result.isOk());
@@ -296,6 +365,8 @@ TEST_F(SecureElementProvisioningTest, InvalidProvisioningTest) {
     result = tee->getRootOfTrust(challenge, &rootOfTrust);
     ASSERT_TRUE(result.isOk());
 
+    validateMacedRootOfTrust(rootOfTrust);
+
     vector<uint8_t> corruptedRootOfTrust = rootOfTrust;
     corruptedRootOfTrust[corruptedRootOfTrust.size() / 2]++;
     result = sb->sendRootOfTrust(corruptedRootOfTrust);