1 /* 2 * Copyright (C) 2024 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.android.adservices.download; 18 19 import static com.android.adservices.service.common.JsonUtils.getStringFromJson; 20 import static com.android.adservices.service.stats.AdServicesStatsLog.AD_SERVICES_ERROR_REPORTED__ERROR_CODE__ENCRYPTION_KEYS_INCORRECT_JSON_VERSION; 21 import static com.android.adservices.service.stats.AdServicesStatsLog.AD_SERVICES_ERROR_REPORTED__ERROR_CODE__ENCRYPTION_KEYS_JSON_PARSING_ERROR; 22 import static com.android.adservices.service.stats.AdServicesStatsLog.AD_SERVICES_ERROR_REPORTED__PPAPI_NAME__COMMON; 23 24 import android.net.Uri; 25 26 import com.android.adservices.LoggerFactory; 27 import com.android.adservices.errorlogging.ErrorLogUtil; 28 import com.android.adservices.service.encryptionkey.EncryptionKey; 29 30 import org.json.JSONException; 31 import org.json.JSONObject; 32 33 import java.util.Locale; 34 import java.util.Optional; 35 import java.util.UUID; 36 37 /** Util class to convert JSON string to {@link EncryptionKey} based on version. */ 38 public final class EncryptionKeyConverterUtil { 39 private static final LoggerFactory.Logger LOGGER = LoggerFactory.getLogger(); 40 private static final int VERSION_3 = 3; 41 42 private static final String KEY_TYPE_KEY = "keyType"; 43 private static final String ENROLLMENT_ID_KEY = "enrollmentId"; 44 private static final String REPORTING_ORIGIN_KEY = "reportingOrigin"; 45 private static final String ENCRYPTION_KEY_URL_KEY = "encryptionKeyUrl"; 46 private static final String PROTOCOL_TYPE_KEY = "protocolType"; 47 private static final String KEY_ID_KEY = "keyId"; 48 private static final String BODY_KEY = "body"; 49 private static final String EXPIRATION_KEY = "expiration"; 50 private static final String VERSION_KEY = "version"; 51 52 /** 53 * Converts {@link JSONObject} to the corresponding {@link EncryptionKey}. 54 * 55 * <p>Returns {@link Optional#empty()} if conversion fails. 56 */ createEncryptionKeyFromJson(JSONObject jsonObject)57 static Optional<EncryptionKey> createEncryptionKeyFromJson(JSONObject jsonObject) { 58 try { 59 if (jsonObject.has(VERSION_KEY)) { 60 // Only version 3 is supported. 61 int version = jsonObject.getInt(VERSION_KEY); 62 if (version == VERSION_3) { 63 return convertVersion3Key(jsonObject); 64 } else { 65 ErrorLogUtil.e( 66 AD_SERVICES_ERROR_REPORTED__ERROR_CODE__ENCRYPTION_KEYS_INCORRECT_JSON_VERSION, 67 AD_SERVICES_ERROR_REPORTED__PPAPI_NAME__COMMON); 68 LOGGER.d("Unsupported encryption key version %d", version); 69 } 70 } 71 } catch (JSONException e) { 72 ErrorLogUtil.e( 73 e, 74 AD_SERVICES_ERROR_REPORTED__ERROR_CODE__ENCRYPTION_KEYS_JSON_PARSING_ERROR, 75 AD_SERVICES_ERROR_REPORTED__PPAPI_NAME__COMMON); 76 } 77 return Optional.empty(); 78 } 79 80 /** Converts version 3 {@link JSONObject} to the corresponding {@link EncryptionKey}. */ convertVersion3Key(JSONObject jsonObject)81 private static Optional<EncryptionKey> convertVersion3Key(JSONObject jsonObject) { 82 /* Expected Version 3 JSON example: 83 * { "keyType": "Signing", "enrollmentId": "TEST0", "reportingOrigin": 84 * "https://adtech.example.com/reporting", "encryptionKeyUrl": 85 * "https://adtech.example.com/keys/fetch/98765", "protocolType": "ECDSA", "keyId": 98765, 86 * "body": "MIIBCgKCAQEAwVACPi9w23nBqQn+BTdRSmYXZGUtIuEhJhTVUZCmYR 87 * +BNdKaIbMnzj2nXmG7nXkJaWUYnmRRhk2XnTKSWbMVzpEtqSIrGxuZUXH9DQ 88 * +3VJXO0BQvScj9KQVcrKPpTZeJrAjj8aS8FmI2+tQvSwFUJNQvPgOODYtveSZVC5YH+kIWC2LSFJQYrGBqDf 89 * +IqhQPjwFUO4T7NUzl7++YigOzMOgAoO5+SxWGOjPNsWt26CkGNzYv+8IfeYZJG3LQs+38dhCSG1qA==", 90 * "expiration": 1682516522000, "version": 3 } 91 */ 92 try { 93 EncryptionKey.Builder builder = new EncryptionKey.Builder(); 94 // Generate UUID for this key 95 builder.setId(UUID.randomUUID().toString()); 96 builder.setKeyType( 97 EncryptionKey.KeyType.valueOf( 98 getStringFromJson(jsonObject, KEY_TYPE_KEY) 99 .toUpperCase(Locale.ENGLISH))); 100 builder.setEnrollmentId(getStringFromJson(jsonObject, ENROLLMENT_ID_KEY)); 101 builder.setReportingOrigin( 102 Uri.parse(getStringFromJson(jsonObject, REPORTING_ORIGIN_KEY))); 103 builder.setEncryptionKeyUrl(getStringFromJson(jsonObject, ENCRYPTION_KEY_URL_KEY)); 104 builder.setProtocolType( 105 EncryptionKey.ProtocolType.valueOf( 106 getStringFromJson(jsonObject, PROTOCOL_TYPE_KEY) 107 .toUpperCase(Locale.ENGLISH))); 108 builder.setKeyCommitmentId(jsonObject.getInt(KEY_ID_KEY)); 109 builder.setBody(getStringFromJson(jsonObject, BODY_KEY)); 110 builder.setExpiration(jsonObject.getLong(EXPIRATION_KEY)); 111 builder.setLastFetchTime(System.currentTimeMillis()); 112 113 EncryptionKey encryptionKey = builder.build(); 114 LOGGER.v( 115 "Successfully built EncryptionKey = %s for enrollment id = %s", 116 encryptionKey.getBody(), encryptionKey.getEnrollmentId()); 117 return Optional.of(encryptionKey); 118 } catch (JSONException | IllegalArgumentException e) { 119 LOGGER.e(e, "Failed parsing for %s", jsonObject); 120 ErrorLogUtil.e( 121 e, 122 AD_SERVICES_ERROR_REPORTED__ERROR_CODE__ENCRYPTION_KEYS_JSON_PARSING_ERROR, 123 AD_SERVICES_ERROR_REPORTED__PPAPI_NAME__COMMON); 124 return Optional.empty(); 125 } 126 } 127 } 128