| /* |
| * Copyright (C) 2019 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package android.content.integrity; |
| |
| import android.annotation.IntDef; |
| import android.annotation.NonNull; |
| import android.annotation.SystemApi; |
| import android.content.integrity.AtomicFormula.BooleanAtomicFormula; |
| import android.content.integrity.AtomicFormula.LongAtomicFormula; |
| import android.content.integrity.AtomicFormula.StringAtomicFormula; |
| import android.os.Parcel; |
| import android.os.Parcelable; |
| |
| import com.android.internal.annotations.VisibleForTesting; |
| |
| import java.lang.annotation.Retention; |
| import java.lang.annotation.RetentionPolicy; |
| import java.util.Arrays; |
| |
| /** |
| * Represents a rule logic/content. |
| * |
| * @hide |
| */ |
| @SystemApi |
| @VisibleForTesting |
| public abstract class IntegrityFormula { |
| |
| /** |
| * A static formula base for package name formulas. |
| * |
| * This formulation is incomplete and should always be used with {@code equals} formulation. |
| * Evaluates to false when used directly and cannot be written as a parcel. |
| */ |
| @NonNull |
| public static final IntegrityFormula PACKAGE_NAME = |
| new StringAtomicFormula(AtomicFormula.PACKAGE_NAME); |
| |
| /** |
| * A static formula base for app certificate formulas. |
| * |
| * This formulation is incomplete and should always be used with {@code equals} formulation. |
| * Evaluates to false when used directly and cannot be written as a parcel. |
| */ |
| @NonNull |
| public static final IntegrityFormula APP_CERTIFICATE = |
| new StringAtomicFormula(AtomicFormula.APP_CERTIFICATE); |
| |
| /** |
| * A static formula base for installer name formulas. |
| * |
| * This formulation is incomplete and should always be used with {@code equals} formulation. |
| * Evaluates to false when used directly and cannot be written as a parcel. |
| */ |
| @NonNull |
| public static final IntegrityFormula INSTALLER_NAME = |
| new StringAtomicFormula(AtomicFormula.INSTALLER_NAME); |
| |
| /** |
| * A static formula base for installer certificate formulas. |
| * |
| * This formulation is incomplete and should always be used with {@code equals} formulation. |
| * Evaluates to false when used directly and cannot be written as a parcel. |
| */ |
| @NonNull |
| public static final IntegrityFormula INSTALLER_CERTIFICATE = |
| new StringAtomicFormula(AtomicFormula.INSTALLER_CERTIFICATE); |
| |
| /** |
| * A static formula base for version code name formulas. |
| * |
| * This formulation is incomplete and should always be used with {@code equals}, |
| * {@code greaterThan} and {@code greaterThanEquals} formulation. Evaluates to false when used |
| * directly and cannot be written as a parcel. |
| */ |
| @NonNull |
| public static final IntegrityFormula VERSION_CODE = |
| new LongAtomicFormula(AtomicFormula.VERSION_CODE); |
| |
| /** |
| * A static formula base for pre-installed status formulas. |
| * |
| * This formulation is incomplete and should always be used with {@code equals} formulation. |
| * Evaluates to false when used directly and cannot be written as a parcel. |
| */ |
| @NonNull |
| public static final IntegrityFormula PRE_INSTALLED = |
| new BooleanAtomicFormula(AtomicFormula.PRE_INSTALLED); |
| |
| /** @hide */ |
| @IntDef( |
| value = { |
| COMPOUND_FORMULA_TAG, |
| STRING_ATOMIC_FORMULA_TAG, |
| LONG_ATOMIC_FORMULA_TAG, |
| BOOLEAN_ATOMIC_FORMULA_TAG |
| }) |
| @Retention(RetentionPolicy.SOURCE) |
| @interface Tag {} |
| |
| /** @hide */ |
| public static final int COMPOUND_FORMULA_TAG = 0; |
| /** @hide */ |
| public static final int STRING_ATOMIC_FORMULA_TAG = 1; |
| /** @hide */ |
| public static final int LONG_ATOMIC_FORMULA_TAG = 2; |
| /** @hide */ |
| public static final int BOOLEAN_ATOMIC_FORMULA_TAG = 3; |
| |
| /** |
| * Returns the tag that identifies the current class. |
| * |
| * @hide |
| */ |
| public abstract @Tag int getTag(); |
| |
| /** |
| * Returns true when the integrity formula is satisfied by the {@code appInstallMetadata}. |
| * |
| * @hide |
| */ |
| public abstract @Tag boolean matches(AppInstallMetadata appInstallMetadata); |
| |
| /** |
| * Returns true when the formula (or one of its atomic formulas) has app certificate as key. |
| * |
| * @hide |
| */ |
| public abstract @Tag boolean isAppCertificateFormula(); |
| |
| /** |
| * Returns true when the formula (or one of its atomic formulas) has installer package name |
| * or installer certificate as key. |
| * |
| * @hide |
| */ |
| public abstract @Tag boolean isInstallerFormula(); |
| |
| /** |
| * Write an {@link IntegrityFormula} to {@link android.os.Parcel}. |
| * |
| * <p>This helper method is needed because non-final class/interface are not allowed to be |
| * {@link Parcelable}. |
| * |
| * @throws IllegalArgumentException if {@link IntegrityFormula} is not a recognized subclass |
| * |
| * @hide |
| */ |
| public static void writeToParcel( |
| @NonNull IntegrityFormula formula, @NonNull Parcel dest, int flags) { |
| dest.writeInt(formula.getTag()); |
| ((Parcelable) formula).writeToParcel(dest, flags); |
| } |
| |
| /** |
| * Read a {@link IntegrityFormula} from a {@link android.os.Parcel}. |
| * |
| * <p>We need this (hacky) helper method because non-final class/interface cannot be {@link |
| * Parcelable} (api lint error). |
| * |
| * @throws IllegalArgumentException if the parcel cannot be parsed |
| * @hide |
| */ |
| @NonNull |
| public static IntegrityFormula readFromParcel(@NonNull Parcel in) { |
| int tag = in.readInt(); |
| switch (tag) { |
| case COMPOUND_FORMULA_TAG: |
| return CompoundFormula.CREATOR.createFromParcel(in); |
| case STRING_ATOMIC_FORMULA_TAG: |
| return StringAtomicFormula.CREATOR.createFromParcel(in); |
| case LONG_ATOMIC_FORMULA_TAG: |
| return LongAtomicFormula.CREATOR.createFromParcel(in); |
| case BOOLEAN_ATOMIC_FORMULA_TAG: |
| return BooleanAtomicFormula.CREATOR.createFromParcel(in); |
| default: |
| throw new IllegalArgumentException("Unknown formula tag " + tag); |
| } |
| } |
| |
| /** |
| * Returns an integrity formula that evaluates to true when value of the key matches to the |
| * provided string value. |
| * |
| * <p>The value will be hashed with SHA256 and the hex digest will be computed; for |
| * all cases except when the key is PACKAGE_NAME or INSTALLER_NAME and the value is less than |
| * 32 characters. |
| * |
| * <p>Throws an {@link IllegalArgumentException} if the key is not string typed. |
| */ |
| @NonNull |
| public IntegrityFormula equalTo(@NonNull String value) { |
| AtomicFormula baseFormula = (AtomicFormula) this; |
| return new AtomicFormula.StringAtomicFormula(baseFormula.getKey(), value); |
| } |
| |
| /** |
| * Returns an integrity formula that evaluates to true when the boolean value of the key matches |
| * the provided boolean value. It can only be used with the boolean comparison keys. |
| * |
| * <p>Throws an {@link IllegalArgumentException} if the key is not boolean typed. |
| */ |
| @NonNull |
| public IntegrityFormula equalTo(boolean value) { |
| AtomicFormula baseFormula = (AtomicFormula) this; |
| return new AtomicFormula.BooleanAtomicFormula(baseFormula.getKey(), value); |
| } |
| |
| /** |
| * Returns a formula that evaluates to true when the value of the key in the package being |
| * installed is equal to {@code value}. |
| * |
| * <p>Throws an {@link IllegalArgumentException} if the key is not long typed. |
| */ |
| @NonNull |
| public IntegrityFormula equalTo(long value) { |
| AtomicFormula baseFormula = (AtomicFormula) this; |
| return new AtomicFormula.LongAtomicFormula(baseFormula.getKey(), AtomicFormula.EQ, value); |
| } |
| |
| /** |
| * Returns a formula that evaluates to true when the value of the key in the package being |
| * installed is greater than {@code value}. |
| * |
| * <p>Throws an {@link IllegalArgumentException} if the key is not long typed. |
| */ |
| @NonNull |
| public IntegrityFormula greaterThan(long value) { |
| AtomicFormula baseFormula = (AtomicFormula) this; |
| return new AtomicFormula.LongAtomicFormula(baseFormula.getKey(), AtomicFormula.GT, value); |
| } |
| |
| /** |
| * Returns a formula that evaluates to true when the value of the key in the package being |
| * installed is greater than or equals to the {@code value}. |
| * |
| * <p>Throws an {@link IllegalArgumentException} if the key is not long typed. |
| */ |
| @NonNull |
| public IntegrityFormula greaterThanOrEquals(long value) { |
| AtomicFormula baseFormula = (AtomicFormula) this; |
| return new AtomicFormula.LongAtomicFormula(baseFormula.getKey(), AtomicFormula.GTE, value); |
| } |
| |
| /** |
| * Returns a formula that evaluates to true when any formula in {@code formulae} evaluates to |
| * true. |
| * |
| * <p>Throws an {@link IllegalArgumentException} if formulae has less than two elements. |
| */ |
| @NonNull |
| public static IntegrityFormula any(@NonNull IntegrityFormula... formulae) { |
| return new CompoundFormula(CompoundFormula.OR, Arrays.asList(formulae)); |
| } |
| |
| /** |
| * Returns a formula that evaluates to true when all formula in {@code formulae} evaluates to |
| * true. |
| * |
| * <p>Throws an {@link IllegalArgumentException} if formulae has less than two elements. |
| */ |
| @NonNull |
| public static IntegrityFormula all(@NonNull IntegrityFormula... formulae) { |
| return new CompoundFormula(CompoundFormula.AND, Arrays.asList(formulae)); |
| } |
| |
| /** |
| * Returns a formula that evaluates to true when {@code formula} evaluates to false. |
| */ |
| @NonNull |
| public static IntegrityFormula not(@NonNull IntegrityFormula formula) { |
| return new CompoundFormula(CompoundFormula.NOT, Arrays.asList(formula)); |
| } |
| |
| // Constructor is package private so it cannot be inherited outside of this package. |
| IntegrityFormula() { |
| } |
| } |