Add limits on BlobHandle label and lease expiry strings. (94b852f9) · Commits · e / os / android_frameworks_base

apex/blobstore/framework/java/android/app/blob/BlobHandle.java

+7 −2

Original line number	Diff line number	Diff line
		@@ -51,6 +51,7 @@ public final class BlobHandle implements Parcelable {
		};

		private static final int LIMIT_BLOB_TAG_LENGTH = 128; // characters
		private static final int LIMIT_BLOB_LABEL_LENGTH = 100; // characters

		/**
		* Cyrptographically secure hash algorithm used to generate hash of the blob this handle is
		@@ -128,6 +129,9 @@ public final class BlobHandle implements Parcelable {
		*
		* @param digest the SHA-256 hash of the blob this is representing.
		* @param label a label indicating what the blob is, that can be surfaced to the user.
		* The length of the label cannot be more than 100 characters. It is recommended
		* to keep this brief. This may be truncated and ellipsized if it is too long
		* to be displayed to the user.
		* @param expiryTimeMillis the time in secs after which the blob should be invalidated and not
		* allowed to be accessed by any other app,
		* in {@link System#currentTimeMillis()} timebase or {@code 0} to
		@@ -205,9 +209,9 @@ public final class BlobHandle implements Parcelable {
		final BlobHandle other = (BlobHandle) obj;
		return this.algorithm.equals(other.algorithm)
		&& Arrays.equals(this.digest, other.digest)
		&& this.label.equals(other.label)
		&& this.label.toString().equals(other.label.toString())
		&& this.expiryTimeMillis == other.expiryTimeMillis
		&& this.tag.equals(tag);
		&& this.tag.equals(other.tag);
		}

		@Override
		@@ -233,6 +237,7 @@ public final class BlobHandle implements Parcelable {
		Preconditions.checkArgumentIsSupported(SUPPORTED_ALGOS, algorithm);
		Preconditions.checkByteArrayNotEmpty(digest, "digest");
		Preconditions.checkStringNotEmpty(label, "label must not be null");
		Preconditions.checkArgument(label.length() <= LIMIT_BLOB_LABEL_LENGTH, "label too long");
		Preconditions.checkArgumentNonnegative(expiryTimeMillis,
		"expiryTimeMillis must not be negative");
		Preconditions.checkStringNotEmpty(tag, "tag must not be null");

apex/blobstore/framework/java/android/app/blob/BlobStoreManager.java

+6 −2

Original line number	Diff line number	Diff line
		@@ -347,7 +347,9 @@ public class BlobStoreManager {
		* @param blobHandle the {@link BlobHandle} representing the blob that the caller wants to
		* acquire a lease for.
		* @param description a short description string that can be surfaced
		* to the user explaining what the blob is used for.
		* to the user explaining what the blob is used for. It is recommended to
		* keep this description brief. This may be truncated and ellipsized
		* if it is too long to be displayed to the user.
		* @param leaseExpiryTimeMillis the time in milliseconds after which the lease can be
		* automatically released, in {@link System#currentTimeMillis()}
		* timebase. If its value is {@code 0}, then the behavior of this
		@@ -458,7 +460,9 @@ public class BlobStoreManager {
		* @param blobHandle the {@link BlobHandle} representing the blob that the caller wants to
		* acquire a lease for.
		* @param description a short description string that can be surfaced
		* to the user explaining what the blob is used for.
		* to the user explaining what the blob is used for. It is recommended to
		* keep this description brief. This may be truncated and
		* ellipsized if it is too long to be displayed to the user.
		*
		* @throws IOException when there is an I/O error while acquiring a lease to the blob.
		* @throws SecurityException when the blob represented by the {@code blobHandle} does not

apex/blobstore/service/java/com/android/server/blob/BlobStoreConfig.java

+26 −0

Original line number	Diff line number	Diff line
		@@ -25,6 +25,7 @@ import android.content.Context;
		import android.os.Environment;
		import android.provider.DeviceConfig;
		import android.provider.DeviceConfig.Properties;
		import android.text.TextUtils;
		import android.util.DataUnit;
		import android.util.Log;
		import android.util.Slog;
		@@ -171,6 +172,13 @@ class BlobStoreConfig {
		public static int MAX_BLOB_ACCESS_PERMITTED_PACKAGES =
		DEFAULT_MAX_BLOB_ACCESS_PERMITTED_PACKAGES;

		/**
		* Denotes the maximum number of characters that a lease description can have.
		*/
		public static final String KEY_LEASE_DESC_CHAR_LIMIT = "lease_desc_char_limit";
		public static int DEFAULT_LEASE_DESC_CHAR_LIMIT = 300;
		public static int LEASE_DESC_CHAR_LIMIT = DEFAULT_LEASE_DESC_CHAR_LIMIT;

		static void refresh(Properties properties) {
		if (!NAMESPACE_BLOBSTORE.equals(properties.getNamespace())) {
		return;
		@@ -221,6 +229,10 @@ class BlobStoreConfig {
		MAX_BLOB_ACCESS_PERMITTED_PACKAGES = properties.getInt(key,
		DEFAULT_MAX_BLOB_ACCESS_PERMITTED_PACKAGES);
		break;
		case KEY_LEASE_DESC_CHAR_LIMIT:
		LEASE_DESC_CHAR_LIMIT = properties.getInt(key,
		DEFAULT_LEASE_DESC_CHAR_LIMIT);
		break;
		default:
		Slog.wtf(TAG, "Unknown key in device config properties: " + key);
		}
		@@ -262,6 +274,8 @@ class BlobStoreConfig {
		fout.println(String.format(dumpFormat, KEY_MAX_BLOB_ACCESS_PERMITTED_PACKAGES,
		MAX_BLOB_ACCESS_PERMITTED_PACKAGES,
		DEFAULT_MAX_BLOB_ACCESS_PERMITTED_PACKAGES));
		fout.println(String.format(dumpFormat, KEY_LEASE_DESC_CHAR_LIMIT,
		LEASE_DESC_CHAR_LIMIT, DEFAULT_LEASE_DESC_CHAR_LIMIT));
		}
		}

		@@ -368,6 +382,18 @@ class BlobStoreConfig {
		return DeviceConfigProperties.MAX_BLOB_ACCESS_PERMITTED_PACKAGES;
		}

		/**
		* Returns the lease description truncated to
		* {@link DeviceConfigProperties#LEASE_DESC_CHAR_LIMIT} characters.
		*/
		public static CharSequence getTruncatedLeaseDescription(CharSequence description) {
		if (TextUtils.isEmpty(description)) {
		return description;
		}
		return TextUtils.trimToLengthWithEllipsis(description,
		DeviceConfigProperties.LEASE_DESC_CHAR_LIMIT);
		}

		@Nullable
		public static File prepareBlobFile(long sessionId) {
		final File blobsDir = prepareBlobsDir();

apex/blobstore/service/java/com/android/server/blob/BlobStoreManagerService.java

+2 −0

Original line number	Diff line number	Diff line
		@@ -1494,6 +1494,8 @@ public class BlobStoreManagerService extends SystemService {
		"leaseExpiryTimeMillis must not be negative");
		Objects.requireNonNull(packageName, "packageName must not be null");

		description = BlobStoreConfig.getTruncatedLeaseDescription(description);

		final int callingUid = Binder.getCallingUid();
		verifyCallingPackage(callingUid, packageName);