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Explicit null-check before use in FileIntegrityService

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Null-ness check are moved to the beginning where the data comes in.

Also remove an unused AssertError which was originally to prevent
crashing system server in unexpected case.

Test: work-in-progress GTS test passed
Bug: 142573505
Change-Id: I7f7afa43dc60a8131cf937273d51781a1033efe0
This commit is contained in:
Victor Hsieh
2020-01-02 14:11:42 -08:00
parent 856ce4a17d
commit 2bcaf1531b
1 changed files with 14 additions and 6 deletions
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20
services/core/java/com/android/server/security/FileIntegrityService.java
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@@ -59,7 +59,7 @@ public class FileIntegrityService extends SystemService {
}
@Override
public boolean isAppSourceCertificateTrusted(byte[] certificateBytes) {
public boolean isAppSourceCertificateTrusted(@Nullable byte[] certificateBytes) {
enforceAnyCallingPermissions(
android.Manifest.permission.REQUEST_INSTALL_PACKAGES,
android.Manifest.permission.INSTALL_PACKAGES);
@@ -67,7 +67,10 @@ public class FileIntegrityService extends SystemService {
if (!isApkVeritySupported()) {
return false;
}
if (certificateBytes == null) {
Slog.w(TAG, "Received a null certificate");
return false;
}
return mTrustedCertificates.contains(toCertificate(certificateBytes));
} catch (CertificateException e) {
Slog.e(TAG, "Failed to convert the certificate: " + e);
@@ -122,7 +125,12 @@ public class FileIntegrityService extends SystemService {
}
for (File cert : files) {
collectCertificate(Files.readAllBytes(cert.toPath()));
byte[] certificateBytes = Files.readAllBytes(cert.toPath());
if (certificateBytes == null) {
Slog.w(TAG, "The certificate file is empty, ignoring " + cert);
continue;
}
collectCertificate(certificateBytes);
}
} catch (IOException e) {
Slog.wtf(TAG, "Failed to load fs-verity certificate from " + path, e);
@@ -146,10 +154,10 @@ public class FileIntegrityService extends SystemService {
* Tries to convert {@code bytes} into an X.509 certificate and store in memory.
* Errors need to be surpressed in order fo the next certificates to still be collected.
*/
private void collectCertificate(@Nullable byte[] bytes) {
private void collectCertificate(@NonNull byte[] bytes) {
try {
mTrustedCertificates.add(toCertificate(bytes));
} catch (CertificateException | AssertionError e) {
} catch (CertificateException e) {
Slog.e(TAG, "Invalid certificate, ignored: " + e);
}
}
@@ -159,7 +167,7 @@ public class FileIntegrityService extends SystemService {
* the rest. The rational is to make it harder to smuggle.
*/
@NonNull
private static X509Certificate toCertificate(@Nullable byte[] bytes)
private static X509Certificate toCertificate(@NonNull byte[] bytes)
throws CertificateException {
Certificate certificate = sCertFactory.generateCertificate(new ByteArrayInputStream(bytes));
if (!(certificate instanceof X509Certificate)) {