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Commit b0b51c32 authored by Mathew Inwood's avatar Mathew Inwood
Browse files

Parser for signed configuration. 

Signed configuration is stored an JSON inside APK meta-data. The format
of the JSON is as follows:

{
  "version": n,
  "config": [
    {
      "minSdk": n,
      "maxSdk": n,
      "values": [
        {
          "key": "global settings key",
          "value": "value for key"
        },
	...
      ],
      ...
    }
  ]
}

Test: atest SignedConfigTest
Bug: 110509075
Change-Id: I4d345b1f03e5c5f5af37de093eb6e5cb2429c42c
parent 9f7fcda6

services/core/java/com/android/server/signedconfig/InvalidConfigException.java

0 → 100644
+33 −0
Original line number Diff line number Diff line 
/*

 * Copyright (C) 2018 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 com.android.server.signedconfig;



/**

 * Thrown when there is a problem parsing the config embedded in an APK.

 */

public class InvalidConfigException extends Exception {



    public InvalidConfigException(String message) {

        super(message);

    }



    public InvalidConfigException(String message, Exception cause) {

        super(message, cause);

    }





}

services/core/java/com/android/server/signedconfig/SignedConfig.java

0 → 100644
+137 −0
Original line number Diff line number Diff line 
/*

 * Copyright (C) 2018 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 com.android.server.signedconfig;



import com.android.internal.annotations.VisibleForTesting;



import org.json.JSONArray;

import org.json.JSONException;

import org.json.JSONObject;



import java.util.ArrayList;

import java.util.Collections;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

import java.util.Set;



/**

 * Represents signed configuration.

 *

 * <p>This configuration should only be used if the signature has already been verified.

 */

public class SignedConfig {



    private static final String KEY_VERSION = "version";

    private static final String KEY_CONFIG = "config";



    private static final String CONFIG_KEY_MIN_SDK = "minSdk";

    private static final String CONFIG_KEY_MAX_SDK = "maxSdk";

    private static final String CONFIG_KEY_VALUES = "values";

    // TODO it may be better to use regular key/value pairs in a JSON object, rather than an array

    // of objects with the 2 keys below.

    private static final String CONFIG_KEY_KEY = "key";

    private static final String CONFIG_KEY_VALUE = "value";



    /**

     * Represents config values targetting to an SDK range.

     */

    public static class PerSdkConfig {

        public final int minSdk;

        public final int maxSdk;

        public final Map<String, String> values;



        public PerSdkConfig(int minSdk, int maxSdk, Map<String, String> values) {

            this.minSdk = minSdk;

            this.maxSdk = maxSdk;

            this.values = Collections.unmodifiableMap(values);

        }



    }



    public final int version;

    public final List<PerSdkConfig> perSdkConfig;



    public SignedConfig(int version, List<PerSdkConfig> perSdkConfig) {

        this.version = version;

        this.perSdkConfig = Collections.unmodifiableList(perSdkConfig);

    }



    /**

     * Find matching sdk config for a given SDK level.

     *

     * @param sdkVersion SDK version of device.

     * @return Matching config, of {@code null} if there is none.

     */

    public PerSdkConfig getMatchingConfig(int sdkVersion) {

        for (PerSdkConfig config : perSdkConfig) {

            if (config.minSdk <= sdkVersion && sdkVersion <= config.maxSdk) {

                return config;

            }

        }

        // nothing matching

        return null;

    }



    /**

     * Parse configuration from an APK.

     *

     * @param config config as read from the APK metadata.

     * @return Parsed configuration.

     * @throws InvalidConfigException If there's a problem parsing the config.

     */

    public static SignedConfig parse(String config, Set<String> allowedKeys)

            throws InvalidConfigException {

        try {

            JSONObject json = new JSONObject(config);

            int version = json.getInt(KEY_VERSION);



            JSONArray perSdkConfig = json.getJSONArray(KEY_CONFIG);

            List<PerSdkConfig> parsedConfigs = new ArrayList<>();

            for (int i = 0; i < perSdkConfig.length(); ++i) {

                parsedConfigs.add(parsePerSdkConfig(perSdkConfig.getJSONObject(i), allowedKeys));

            }



            return new SignedConfig(version, parsedConfigs);

        } catch (JSONException e) {

            throw new InvalidConfigException("Could not parse JSON", e);

        }



    }



    @VisibleForTesting

    static PerSdkConfig parsePerSdkConfig(JSONObject json, Set<String> allowedKeys)

            throws JSONException, InvalidConfigException {

        int minSdk = json.getInt(CONFIG_KEY_MIN_SDK);

        int maxSdk = json.getInt(CONFIG_KEY_MAX_SDK);

        JSONArray valueArray = json.getJSONArray(CONFIG_KEY_VALUES);

        Map<String, String> values = new HashMap<>();

        for (int i = 0; i < valueArray.length(); ++i) {

            JSONObject keyValuePair = valueArray.getJSONObject(i);

            String key = keyValuePair.getString(CONFIG_KEY_KEY);

            String value = keyValuePair.has(CONFIG_KEY_VALUE)

                    ? keyValuePair.getString(CONFIG_KEY_VALUE)

                    : null;

            if (!allowedKeys.contains(key)) {

                throw new InvalidConfigException("Config key " + key + " is not allowed");

            }

            values.put(key, value);

        }

        return new PerSdkConfig(minSdk, maxSdk, values);

    }



}

services/tests/servicestests/src/com/android/server/signedconfig/SignedConfigTest.java

0 → 100644
+328 −0
Original line number Diff line number Diff line 
/*

 * Copyright (C) 2018 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 com.android.server.signedconfig;



import static com.google.common.truth.Truth.assertThat;



import static org.junit.Assert.fail;



import static java.util.Collections.emptySet;



import androidx.test.runner.AndroidJUnit4;



import com.google.common.collect.Sets;



import org.json.JSONException;

import org.json.JSONObject;

import org.junit.Test;

import org.junit.runner.RunWith;



import java.util.Arrays;

import java.util.Collections;

import java.util.Set;





/**

 * Tests for {@link SignedConfig}

 */

@RunWith(AndroidJUnit4.class)

public class SignedConfigTest {



    private static Set<String> setOf(String... values) {

        return Sets.newHashSet(values);

    }



    @Test

    public void testParsePerSdkConfigSdkMinMax() throws JSONException, InvalidConfigException {

        JSONObject json = new JSONObject("{\"minSdk\":2, \"maxSdk\": 3, \"values\": []}");

        SignedConfig.PerSdkConfig config = SignedConfig.parsePerSdkConfig(json, emptySet());

        assertThat(config.minSdk).isEqualTo(2);

        assertThat(config.maxSdk).isEqualTo(3);

    }



    @Test

    public void testParsePerSdkConfigNoMinSdk() throws JSONException {

        JSONObject json = new JSONObject("{\"maxSdk\": 3, \"values\": []}");

        try {

            SignedConfig.parsePerSdkConfig(json, emptySet());

            fail("Expected InvalidConfigException or JSONException");

        } catch (JSONException | InvalidConfigException e) {

            // expected

        }

    }



    @Test

    public void testParsePerSdkConfigNoMaxSdk() throws JSONException {

        JSONObject json = new JSONObject("{\"minSdk\": 1, \"values\": []}");

        try {

            SignedConfig.parsePerSdkConfig(json, emptySet());

            fail("Expected InvalidConfigException or JSONException");

        } catch (JSONException | InvalidConfigException e) {

            // expected

        }

    }



    @Test

    public void testParsePerSdkConfigNoValues() throws JSONException {

        JSONObject json = new JSONObject("{\"minSdk\": 1, \"maxSdk\": 3}");

        try {

            SignedConfig.parsePerSdkConfig(json, emptySet());

            fail("Expected InvalidConfigException or JSONException");

        } catch (JSONException | InvalidConfigException e) {

            // expected

        }

    }



    @Test

    public void testParsePerSdkConfigSdkNullMinSdk() throws JSONException, InvalidConfigException {

        JSONObject json = new JSONObject("{\"minSdk\":null, \"maxSdk\": 3, \"values\": []}");

        try {

            SignedConfig.parsePerSdkConfig(json, emptySet());

            fail("Expected InvalidConfigException or JSONException");

        } catch (JSONException | InvalidConfigException e) {

            // expected

        }

    }



    @Test

    public void testParsePerSdkConfigSdkNullMaxSdk() throws JSONException, InvalidConfigException {

        JSONObject json = new JSONObject("{\"minSdk\":1, \"maxSdk\": null, \"values\": []}");

        try {

            SignedConfig.parsePerSdkConfig(json, emptySet());

            fail("Expected InvalidConfigException or JSONException");

        } catch (JSONException | InvalidConfigException e) {

            // expected

        }

    }



    @Test

    public void testParsePerSdkConfigNullValues() throws JSONException {

        JSONObject json = new JSONObject("{\"minSdk\": 1, \"maxSdk\": 3, \"values\": null}");

        try {

            SignedConfig.parsePerSdkConfig(json, emptySet());

            fail("Expected InvalidConfigException or JSONException");

        } catch (JSONException | InvalidConfigException e) {

            // expected

        }

    }



    @Test

    public void testParsePerSdkConfigZeroValues()

            throws JSONException, InvalidConfigException {

        JSONObject json = new JSONObject("{\"minSdk\": 1, \"maxSdk\": 3, \"values\": []}");

        SignedConfig.PerSdkConfig config = SignedConfig.parsePerSdkConfig(json, setOf("a", "b"));

        assertThat(config.values).hasSize(0);

    }



    @Test

    public void testParsePerSdkConfigSingleKey()

            throws JSONException, InvalidConfigException {

        JSONObject json = new JSONObject(

                "{\"minSdk\": 1, \"maxSdk\": 1, \"values\": [{\"key\":\"a\", \"value\": \"1\"}]}");

        SignedConfig.PerSdkConfig config = SignedConfig.parsePerSdkConfig(json, setOf("a", "b"));

        assertThat(config.values).containsExactly("a", "1");

    }



    @Test

    public void testParsePerSdkConfigMultiKeys()

            throws JSONException, InvalidConfigException {

        JSONObject json = new JSONObject(

                "{\"minSdk\": 1, \"maxSdk\": 1, \"values\": [{\"key\":\"a\", \"value\": \"1\"}, "

                        + "{\"key\":\"c\", \"value\": \"2\"}]}");

        SignedConfig.PerSdkConfig config = SignedConfig.parsePerSdkConfig(

                json, setOf("a", "b", "c"));

        assertThat(config.values).containsExactly("a", "1", "c", "2");

    }



    @Test

    public void testParsePerSdkConfigSingleKeyNotAllowed() throws JSONException {

        JSONObject json = new JSONObject(

                "{\"minSdk\": 1, \"maxSdk\": 1, \"values\": [{\"key\":\"a\", \"value\": \"1\"}]}");

        try {

            SignedConfig.parsePerSdkConfig(json, setOf("b"));

            fail("Expected InvalidConfigException or JSONException");

        } catch (JSONException | InvalidConfigException e) {

            // expected

        }

    }



    @Test

    public void testParsePerSdkConfigSingleKeyNoValue()

            throws JSONException, InvalidConfigException {

        JSONObject json = new JSONObject(

                "{\"minSdk\": 1, \"maxSdk\": 1, \"values\": [{\"key\":\"a\"}]}");

        SignedConfig.PerSdkConfig config = SignedConfig.parsePerSdkConfig(json, setOf("a", "b"));

        assertThat(config.values).containsExactly("a", null);

    }



    @Test

    public void testParsePerSdkConfigValuesInvalid() throws JSONException  {

        JSONObject json = new JSONObject("{\"minSdk\": 1, \"maxSdk\": 1,  \"values\": \"foo\"}");

        try {

            SignedConfig.parsePerSdkConfig(json, emptySet());

            fail("Expected InvalidConfigException or JSONException");

        } catch (JSONException | InvalidConfigException e) {

            // expected

        }

    }



    @Test

    public void testParsePerSdkConfigConfigEntryInvalid() throws JSONException {

        JSONObject json = new JSONObject("{\"minSdk\": 1, \"maxSdk\": 1,  \"values\": [1, 2]}");

        try {

            SignedConfig.parsePerSdkConfig(json, emptySet());

            fail("Expected InvalidConfigException or JSONException");

        } catch (JSONException | InvalidConfigException e) {

            // expected

        }

    }



    @Test

    public void testParsePerSdkConfigConfigEntryNull() throws JSONException {

        JSONObject json = new JSONObject("{\"minSdk\": 1, \"maxSdk\": 1,  \"values\": [null]}");

        try {

            SignedConfig.parsePerSdkConfig(json, emptySet());

            fail("Expected InvalidConfigException or JSONException");

        } catch (JSONException | InvalidConfigException e) {

            // expected

        }

    }



    @Test

    public void testParseVersion() throws InvalidConfigException {

        SignedConfig config = SignedConfig.parse(

                "{\"version\": 1, \"config\": []}", emptySet());

        assertThat(config.version).isEqualTo(1);

    }



    @Test

    public void testParseVersionInvalid() {

        try {

            SignedConfig.parse("{\"version\": \"notanint\", \"config\": []}", emptySet());

            fail("Expected InvalidConfigException");

        } catch (InvalidConfigException e) {

            //expected

        }

    }



    @Test

    public void testParseNoVersion() {

        try {

            SignedConfig.parse("{\"config\": []}", emptySet());

            fail("Expected InvalidConfigException");

        } catch (InvalidConfigException e) {

            //expected

        }

    }



    @Test

    public void testParseNoConfig() {

        try {

            SignedConfig.parse("{\"version\": 1}", emptySet());

            fail("Expected InvalidConfigException");

        } catch (InvalidConfigException e) {

            //expected

        }

    }



    @Test

    public void testParseConfigNull() {

        try {

            SignedConfig.parse("{\"version\": 1, \"config\": null}", emptySet());

            fail("Expected InvalidConfigException");

        } catch (InvalidConfigException e) {

            //expected

        }

    }



    @Test

    public void testParseVersionNull() {

        try {

            SignedConfig.parse("{\"version\": null, \"config\": []}", emptySet());

            fail("Expected InvalidConfigException");

        } catch (InvalidConfigException e) {

            //expected

        }

    }



    @Test

    public void testParseConfigInvalidEntry() {

        try {

            SignedConfig.parse("{\"version\": 1, \"config\": [{}]}", emptySet());

            fail("Expected InvalidConfigException");

        } catch (InvalidConfigException e) {

            //expected

        }

    }



    @Test

    public void testParseSdkConfigSingle() throws InvalidConfigException {

        SignedConfig config = SignedConfig.parse(

                "{\"version\": 1, \"config\":[{\"minSdk\": 1, \"maxSdk\": 1, \"values\": []}]}",

                emptySet());

        assertThat(config.perSdkConfig).hasSize(1);

    }



    @Test

    public void testParseSdkConfigMultiple() throws InvalidConfigException {

        SignedConfig config = SignedConfig.parse(

                "{\"version\": 1, \"config\":[{\"minSdk\": 1, \"maxSdk\": 1, \"values\": []}, "

                        + "{\"minSdk\": 2, \"maxSdk\": 2, \"values\": []}]}", emptySet());

        assertThat(config.perSdkConfig).hasSize(2);

    }



    @Test

    public void testGetMatchingConfigFirst() {

        SignedConfig.PerSdkConfig sdk1 = new SignedConfig.PerSdkConfig(

                1, 1, Collections.emptyMap());

        SignedConfig.PerSdkConfig sdk2 = new SignedConfig.PerSdkConfig(

                2, 2, Collections.emptyMap());

        SignedConfig config = new SignedConfig(0, Arrays.asList(sdk1, sdk2));

        assertThat(config.getMatchingConfig(1)).isEqualTo(sdk1);

    }



    @Test

    public void testGetMatchingConfigSecond() {

        SignedConfig.PerSdkConfig sdk1 = new SignedConfig.PerSdkConfig(

                1, 1, Collections.emptyMap());

        SignedConfig.PerSdkConfig sdk2 = new SignedConfig.PerSdkConfig(

                2, 2, Collections.emptyMap());

        SignedConfig config = new SignedConfig(0, Arrays.asList(sdk1, sdk2));

        assertThat(config.getMatchingConfig(2)).isEqualTo(sdk2);

    }



    @Test

    public void testGetMatchingConfigInRange() {

        SignedConfig.PerSdkConfig sdk13 = new SignedConfig.PerSdkConfig(

                1, 3, Collections.emptyMap());

        SignedConfig.PerSdkConfig sdk46 = new SignedConfig.PerSdkConfig(

                4, 6, Collections.emptyMap());

        SignedConfig config = new SignedConfig(0, Arrays.asList(sdk13, sdk46));

        assertThat(config.getMatchingConfig(2)).isEqualTo(sdk13);

    }



    @Test

    public void testGetMatchingConfigNoMatch() {

        SignedConfig.PerSdkConfig sdk1 = new SignedConfig.PerSdkConfig(

                1, 1, Collections.emptyMap());

        SignedConfig.PerSdkConfig sdk2 = new SignedConfig.PerSdkConfig(

                2, 2, Collections.emptyMap());

        SignedConfig config = new SignedConfig(0, Arrays.asList(sdk1, sdk2));

        assertThat(config.getMatchingConfig(3)).isNull();

    }



}