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binder: add hasPermissions security policy and test
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@marvinliu
marvinliu committed May 2, 2022
1 parent 812264e commit 80f1cbf
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Showing 2 changed files with 265 additions and 20 deletions.
44 changes: 44 additions & 0 deletions binder/src/main/java/io/grpc/binder/SecurityPolicies.java
View file
Expand Up @@ -25,6 +25,7 @@
import android.os.Process;
import com.google.common.base.Preconditions;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableSet;
import com.google.errorprone.annotations.CheckReturnValue;
import io.grpc.ExperimentalApi;
import io.grpc.Status;
Expand Down Expand Up @@ -216,4 +217,47 @@ public Status checkAuthorization(int uid) {
}
};
}

/**
* Creates a {@link SecurityPolicy} which checks if the caller has all of the given permissions
* from {@code permissions}.
*
* @param permissions all permissions that the calling package needs to have
* @throws NullPointerException if any of the inputs are {@code null}
* @throws IllegalArgumentException if {@code permissions} is empty
*/
public static SecurityPolicy hasPermissions(
PackageManager packageManager, ImmutableSet<String> permissions) {
Preconditions.checkNotNull(packageManager, "packageManager");
Preconditions.checkNotNull(permissions, "permissions");
Preconditions.checkArgument(!permissions.isEmpty(), "permissions");
return new SecurityPolicy() {
@Override
public Status checkAuthorization(int uid) {
return checkPermissions(uid, packageManager, permissions);
}
};
}

private static Status checkPermissions(
int uid, PackageManager packageManager, ImmutableSet<String> permissions) {
String[] packages = packageManager.getPackagesForUid(uid);
if (packages == null || packages.length == 0) {
return Status.UNAUTHENTICATED.withDescription(
"Rejected by permission check security policy. No packages found for uid");
}
for (String pkg : packages) {
for (String permission : permissions) {
if (packageManager.checkPermission(permission, pkg) != PackageManager.PERMISSION_GRANTED) {
return Status.PERMISSION_DENIED.withDescription(
"Rejected by permission check security policy. "
+ pkg
+ " does not have permission "
+ permission);
}
}
}

return Status.OK;
}
}
241 changes: 221 additions & 20 deletions binder/src/test/java/io/grpc/binder/SecurityPoliciesTest.java
View file
Expand Up @@ -16,6 +16,11 @@

package io.grpc.binder;

import static android.Manifest.permission.ACCESS_COARSE_LOCATION;
import static android.Manifest.permission.ACCESS_FINE_LOCATION;
import static android.Manifest.permission.WRITE_EXTERNAL_STORAGE;
import static android.content.pm.PackageInfo.REQUESTED_PERMISSION_GRANTED;
import static com.google.common.base.Preconditions.checkState;
import static com.google.common.truth.Truth.assertThat;
import static org.robolectric.Shadows.shadowOf;

Expand All @@ -26,8 +31,9 @@
import android.os.Process;
import androidx.test.core.app.ApplicationProvider;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableSet;
import io.grpc.Status;
import io.grpc.binder.SecurityPolicy;
import java.util.HashMap;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
Expand All @@ -39,7 +45,6 @@ public final class SecurityPoliciesTest {
private static final int MY_UID = Process.myUid();
private static final int OTHER_UID = MY_UID + 1;
private static final int OTHER_UID_SAME_SIGNATURE = MY_UID + 2;
private static final int OTHER_UID_NO_SIGNATURE = MY_UID + 3;
private static final int OTHER_UID_UNKNOWN = MY_UID + 4;

private static final String PERMISSION_DENIED_REASONS = "some reasons";
Expand All @@ -49,7 +54,6 @@ public final class SecurityPoliciesTest {

private static final String OTHER_UID_PACKAGE_NAME = "other.package";
private static final String OTHER_UID_SAME_SIGNATURE_PACKAGE_NAME = "other.package.samesignature";
private static final String OTHER_UID_NO_SIGNATURE_PACKAGE_NAME = "other.package.nosignature";

private Context appContext;
private PackageManager packageManager;
Expand All @@ -60,24 +64,22 @@ public final class SecurityPoliciesTest {
public void setUp() {
appContext = ApplicationProvider.getApplicationContext();
packageManager = appContext.getPackageManager();
installPackage(MY_UID, appContext.getPackageName(), SIG1);
installPackage(OTHER_UID, OTHER_UID_PACKAGE_NAME, SIG2);
installPackage(OTHER_UID_SAME_SIGNATURE, OTHER_UID_SAME_SIGNATURE_PACKAGE_NAME, SIG1);
installPackage(OTHER_UID_NO_SIGNATURE, OTHER_UID_NO_SIGNATURE_PACKAGE_NAME);
}

@SuppressWarnings("deprecation")
private void installPackage(int uid, String packageName, Signature... signatures) {
PackageInfo info = new PackageInfo();
info.packageName = packageName;
info.signatures = signatures;
shadowOf(packageManager).installPackage(info);
shadowOf(packageManager).setPackagesForUid(uid, packageName);
private void installPackages(int uid, PackageInfo... packageInfo) {
String[] packageNames = new String[packageInfo.length];
for (int i = 0; i < packageInfo.length; i++) {
shadowOf(packageManager).installPackage(packageInfo[i]);
packageNames[i] = packageInfo[i].packageName;
}
shadowOf(packageManager).setPackagesForUid(uid, packageNames);
}

@Test
public void testInternalOnly() throws Exception {
policy = SecurityPolicies.internalOnly();

assertThat(policy.checkAuthorization(MY_UID).getCode()).isEqualTo(Status.OK.getCode());
assertThat(policy.checkAuthorization(OTHER_UID).getCode())
.isEqualTo(Status.PERMISSION_DENIED.getCode());
Expand All @@ -99,6 +101,11 @@ public void testPermissionDenied() throws Exception {
@Test
public void testHasSignature_succeedsIfPackageNameAndSignaturesMatch()
throws Exception {
PackageInfo info =
newBuilder().setPackageName(OTHER_UID_PACKAGE_NAME).setSignatures(SIG2).build();

installPackages(OTHER_UID, info);

policy = SecurityPolicies.hasSignature(packageManager, OTHER_UID_PACKAGE_NAME, SIG2);

// THEN UID for package that has SIG2 will be authorized
Expand All @@ -107,6 +114,14 @@ public void testHasSignature_succeedsIfPackageNameAndSignaturesMatch()

@Test
public void testHasSignature_failsIfPackageNameDoesNotMatch() throws Exception {
PackageInfo info =
newBuilder()
.setPackageName(OTHER_UID_SAME_SIGNATURE_PACKAGE_NAME)
.setSignatures(SIG1)
.build();

installPackages(OTHER_UID_SAME_SIGNATURE, info);

policy = SecurityPolicies.hasSignature(packageManager, appContext.getPackageName(), SIG1);

// THEN UID for package that has SIG1 but different package name will not be authorized
Expand All @@ -116,6 +131,11 @@ public void testHasSignature_failsIfPackageNameDoesNotMatch() throws Exception {

@Test
public void testHasSignature_failsIfSignatureDoesNotMatch() throws Exception {
PackageInfo info =
newBuilder().setPackageName(OTHER_UID_PACKAGE_NAME).setSignatures(SIG2).build();

installPackages(OTHER_UID, info);

policy = SecurityPolicies.hasSignature(packageManager, OTHER_UID_PACKAGE_NAME, SIG1);

// THEN UID for package that doesn't have SIG1 will not be authorized
Expand All @@ -126,6 +146,11 @@ public void testHasSignature_failsIfSignatureDoesNotMatch() throws Exception {
@Test
public void testOneOfSignatures_succeedsIfPackageNameAndSignaturesMatch()
throws Exception {
PackageInfo info =
newBuilder().setPackageName(OTHER_UID_PACKAGE_NAME).setSignatures(SIG2).build();

installPackages(OTHER_UID, info);

policy =
SecurityPolicies.oneOfSignatures(
packageManager, OTHER_UID_PACKAGE_NAME, ImmutableList.of(SIG2));
Expand All @@ -136,6 +161,14 @@ public void testOneOfSignatures_succeedsIfPackageNameAndSignaturesMatch()

@Test
public void testOneOfSignature_failsIfAllSignaturesDoNotMatch() throws Exception {
PackageInfo info =
newBuilder()
.setPackageName(OTHER_UID_SAME_SIGNATURE_PACKAGE_NAME)
.setSignatures(SIG1)
.build();

installPackages(OTHER_UID_SAME_SIGNATURE, info);

policy =
SecurityPolicies.oneOfSignatures(
packageManager,
Expand All @@ -150,11 +183,14 @@ public void testOneOfSignature_failsIfAllSignaturesDoNotMatch() throws Exception
@Test
public void testOneOfSignature_succeedsIfPackageNameAndOneOfSignaturesMatch()
throws Exception {
PackageInfo info =
newBuilder().setPackageName(OTHER_UID_PACKAGE_NAME).setSignatures(SIG2).build();

installPackages(OTHER_UID, info);

policy =
SecurityPolicies.oneOfSignatures(
packageManager,
OTHER_UID_PACKAGE_NAME,
ImmutableList.of(SIG1, SIG2));
packageManager, OTHER_UID_PACKAGE_NAME, ImmutableList.of(SIG1, SIG2));

// THEN UID for package that has SIG2 will be authorized
assertThat(policy.checkAuthorization(OTHER_UID).getCode()).isEqualTo(Status.OK.getCode());
Expand All @@ -164,12 +200,177 @@ public void testOneOfSignature_succeedsIfPackageNameAndOneOfSignaturesMatch()
public void testHasSignature_failsIfUidUnknown() throws Exception {
policy =
SecurityPolicies.hasSignature(
packageManager,
appContext.getPackageName(),
SIG1);
packageManager,
appContext.getPackageName(),
SIG1);

assertThat(policy.checkAuthorization(OTHER_UID_UNKNOWN).getCode())
.isEqualTo(Status.UNAUTHENTICATED.getCode());
.isEqualTo(Status.UNAUTHENTICATED.getCode());
}

@Test
public void testHasPermissions_sharedUserId_succeedsIfAllPackageHavePermissions()
throws Exception {
PackageInfo info =
newBuilder()
.setPackageName(OTHER_UID_PACKAGE_NAME)
.setPermission(ACCESS_FINE_LOCATION, REQUESTED_PERMISSION_GRANTED)
.setPermission(ACCESS_COARSE_LOCATION, REQUESTED_PERMISSION_GRANTED)
.build();

PackageInfo infoSamePerms =
newBuilder()
.setPackageName(OTHER_UID_SAME_SIGNATURE_PACKAGE_NAME)
.setPermission(ACCESS_FINE_LOCATION, REQUESTED_PERMISSION_GRANTED)
.setPermission(ACCESS_COARSE_LOCATION, REQUESTED_PERMISSION_GRANTED)
.build();

installPackages(OTHER_UID, info, infoSamePerms);

policy =
SecurityPolicies.hasPermissions(
packageManager, ImmutableSet.of(ACCESS_FINE_LOCATION, ACCESS_COARSE_LOCATION));
assertThat(policy.checkAuthorization(OTHER_UID).getCode()).isEqualTo(Status.OK.getCode());
}

@Test
public void testHasPermissions_sharedUserId_failsIfOnePackageHasNoPermissions() throws Exception {
PackageInfo info =
newBuilder()
.setPackageName(OTHER_UID_PACKAGE_NAME)
.setPermission(ACCESS_FINE_LOCATION, REQUESTED_PERMISSION_GRANTED)
.build();

PackageInfo infoNoPerms =
newBuilder()
.setPackageName(OTHER_UID_SAME_SIGNATURE_PACKAGE_NAME)
.setPermission(ACCESS_FINE_LOCATION, 0)
.build();

installPackages(OTHER_UID, info, infoNoPerms);

policy = SecurityPolicies.hasPermissions(packageManager, ImmutableSet.of(ACCESS_FINE_LOCATION));
assertThat(policy.checkAuthorization(OTHER_UID).getCode())
.isEqualTo(Status.PERMISSION_DENIED.getCode());
assertThat(policy.checkAuthorization(OTHER_UID).getDescription())
.contains(ACCESS_FINE_LOCATION);
assertThat(policy.checkAuthorization(OTHER_UID).getDescription())
.contains(OTHER_UID_SAME_SIGNATURE_PACKAGE_NAME);
}

@Test
public void testHasPermissions_succeedsIfPackageHasPermissions() throws Exception {
PackageInfo info =
newBuilder()
.setPackageName(OTHER_UID_PACKAGE_NAME)
.setPermission(ACCESS_FINE_LOCATION, REQUESTED_PERMISSION_GRANTED)
.setPermission(ACCESS_COARSE_LOCATION, REQUESTED_PERMISSION_GRANTED)
.setPermission(WRITE_EXTERNAL_STORAGE, 0)
.build();

installPackages(OTHER_UID, info);

policy =
SecurityPolicies.hasPermissions(
packageManager, ImmutableSet.of(ACCESS_FINE_LOCATION, ACCESS_COARSE_LOCATION));
assertThat(policy.checkAuthorization(OTHER_UID).getCode()).isEqualTo(Status.OK.getCode());
}

@Test
public void testHasPermissions_failsIfPackageDoesNotHaveOnePermission() throws Exception {
PackageInfo info =
newBuilder()
.setPackageName(OTHER_UID_PACKAGE_NAME)
.setPermission(ACCESS_FINE_LOCATION, REQUESTED_PERMISSION_GRANTED)
.setPermission(ACCESS_COARSE_LOCATION, REQUESTED_PERMISSION_GRANTED)
.setPermission(WRITE_EXTERNAL_STORAGE, 0)
.build();

installPackages(OTHER_UID, info);

policy =
SecurityPolicies.hasPermissions(
packageManager, ImmutableSet.of(ACCESS_FINE_LOCATION, WRITE_EXTERNAL_STORAGE));
assertThat(policy.checkAuthorization(OTHER_UID).getCode())
.isEqualTo(Status.PERMISSION_DENIED.getCode());
assertThat(policy.checkAuthorization(OTHER_UID).getDescription())
.contains(WRITE_EXTERNAL_STORAGE);
assertThat(policy.checkAuthorization(OTHER_UID).getDescription())
.contains(OTHER_UID_PACKAGE_NAME);
}

@Test
public void testHasPermissions_failsIfPackageDoesNotHavePermissions() throws Exception {
PackageInfo info =
newBuilder()
.setPackageName(OTHER_UID_PACKAGE_NAME)
.setPermission(ACCESS_FINE_LOCATION, REQUESTED_PERMISSION_GRANTED)
.setPermission(ACCESS_COARSE_LOCATION, REQUESTED_PERMISSION_GRANTED)
.setPermission(WRITE_EXTERNAL_STORAGE, 0)
.build();

installPackages(OTHER_UID, info);

policy =
SecurityPolicies.hasPermissions(packageManager, ImmutableSet.of(WRITE_EXTERNAL_STORAGE));
assertThat(policy.checkAuthorization(OTHER_UID).getCode())
.isEqualTo(Status.PERMISSION_DENIED.getCode());
assertThat(policy.checkAuthorization(OTHER_UID).getDescription())
.contains(WRITE_EXTERNAL_STORAGE);
assertThat(policy.checkAuthorization(OTHER_UID).getDescription())
.contains(OTHER_UID_PACKAGE_NAME);
}

private static PackageInfoBuilder newBuilder() {
return new PackageInfoBuilder();
}

private static class PackageInfoBuilder {
private String packageName;
private Signature[] signatures;
private final HashMap<String, Integer> permissions = new HashMap<>();

public PackageInfoBuilder setPackageName(String packageName) {
this.packageName = packageName;
return this;
}

public PackageInfoBuilder setPermission(String permissionName, int permissionFlag) {
this.permissions.put(permissionName, permissionFlag);
return this;
}

public PackageInfoBuilder setSignatures(Signature... signatures) {
this.signatures = signatures;
return this;
}

public PackageInfo build() {
checkState(this.packageName != null, "packageName is a mandatory field");

PackageInfo packageInfo = new PackageInfo();

packageInfo.packageName = this.packageName;

if (this.signatures != null) {
packageInfo.signatures = this.signatures;
}

if (!this.permissions.isEmpty()) {
String[] requestedPermissions =
this.permissions.keySet().toArray(new String[this.permissions.size()]);
int[] requestedPermissionsFlags = new int[requestedPermissions.length];

for (int i = 0; i < requestedPermissions.length; i++) {
requestedPermissionsFlags[i] = this.permissions.get(requestedPermissions[i]);
}

packageInfo.requestedPermissions = requestedPermissions;
packageInfo.requestedPermissionsFlags = requestedPermissionsFlags;
}

return packageInfo;
}
}

@Test
Expand Down

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