Test validity of device-unique attestation chain
Test the validity of the chain produced when device-unique attestation
is requested.
When the caller requests that the key attestation be signed using the
device-unique attestation key, the chain will look different than
a chain signed by the batch key (common case):
(1) The chain is exactly of length 2.
(2) The root is self-signed and is unique to the device.
Test that the chain is correctly signed in this change. The root is not
currently correctly self-signed, so don't test (2) yet.
Bug: 189425310
Bug: 187803288
Test: atest VtsHalKeymasterV4_1TargetTest:PerInstance/DeviceUniqueAttestationTest
Ignore-AOSP-First: Already merged in aosp
Merged-In: I91578eb2b7588685cc86c467423e9394c3f3c262
Change-Id: I7e83ba7c9c8c68b95b1456fb37bb5aa939c4e6f8
diff --git a/keymaster/4.1/vts/functional/DeviceUniqueAttestationTest.cpp b/keymaster/4.1/vts/functional/DeviceUniqueAttestationTest.cpp
index 0639da8..3d97daf 100644
--- a/keymaster/4.1/vts/functional/DeviceUniqueAttestationTest.cpp
+++ b/keymaster/4.1/vts/functional/DeviceUniqueAttestationTest.cpp
@@ -16,6 +16,7 @@
#define LOG_TAG "keymaster_hidl_hal_test"
#include <cutils/log.h>
+#include <vector>
#include "Keymaster4_1HidlTest.h"
@@ -178,6 +179,33 @@
<< DIFFERENCE(expected_hw_enforced, attestation.hardware_enforced);
}
+X509_Ptr parse_cert_blob(const std::vector<uint8_t>& blob) {
+ const uint8_t* p = blob.data();
+ return X509_Ptr(d2i_X509(nullptr /* allocate new */, &p, blob.size()));
+}
+
+bool check_certificate_chain_signatures(const hidl_vec<hidl_vec<uint8_t>>& cert_chain) {
+ // TODO: Check that root is self-signed once b/187803288 is resolved.
+ for (size_t i = 0; i < cert_chain.size() - 1; ++i) {
+ X509_Ptr key_cert(parse_cert_blob(cert_chain[i]));
+ X509_Ptr signing_cert(parse_cert_blob(cert_chain[i + 1]));
+
+ if (!key_cert.get() || !signing_cert.get()) {
+ return false;
+ }
+
+ EVP_PKEY_Ptr signing_pubkey(X509_get_pubkey(signing_cert.get()));
+ if (!signing_pubkey.get()) {
+ return false;
+ }
+
+ if (!X509_verify(key_cert.get(), signing_pubkey.get())) {
+ return false;
+ }
+ }
+ return true;
+}
+
} // namespace
using std::string;
@@ -243,6 +271,7 @@
EXPECT_EQ(ErrorCode::OK, result);
EXPECT_EQ(2U, cert_chain.size());
+ EXPECT_TRUE(check_certificate_chain_signatures(cert_chain));
if (dumpAttestations) {
for (auto cert_ : cert_chain) dumpContent(bin2hex(cert_));
}
@@ -289,6 +318,7 @@
EXPECT_EQ(ErrorCode::OK, result);
EXPECT_EQ(2U, cert_chain.size());
+ EXPECT_TRUE(check_certificate_chain_signatures(cert_chain));
if (dumpAttestations) {
for (auto cert_ : cert_chain) dumpContent(bin2hex(cert_));
}