Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2015 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 android.security.keystore; |
| 18 | |
| 19 | import android.annotation.IntRange; |
| 20 | import android.annotation.NonNull; |
| 21 | import android.annotation.Nullable; |
Alex Klyubin | 83cc7a3 | 2015-06-16 10:44:11 -0700 | [diff] [blame] | 22 | import android.app.KeyguardManager; |
| 23 | import android.hardware.fingerprint.FingerprintManager; |
Rubin Xu | 59ced28 | 2017-01-30 23:39:12 +0000 | [diff] [blame] | 24 | import android.security.GateKeeper; |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 25 | |
| 26 | import java.security.Key; |
Alex Klyubin | 83cc7a3 | 2015-06-16 10:44:11 -0700 | [diff] [blame] | 27 | import java.security.Signature; |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 28 | import java.security.KeyStore.ProtectionParameter; |
| 29 | import java.security.cert.Certificate; |
| 30 | import java.util.Date; |
| 31 | |
| 32 | import javax.crypto.Cipher; |
Alex Klyubin | 83cc7a3 | 2015-06-16 10:44:11 -0700 | [diff] [blame] | 33 | import javax.crypto.Mac; |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 34 | |
| 35 | /** |
| 36 | * Specification of how a key or key pair is secured when imported into the |
Alex Klyubin | 72245d7 | 2015-08-11 06:41:13 -0700 | [diff] [blame] | 37 | * <a href="{@docRoot}training/articles/keystore.html">Android Keystore system</a>. This class |
| 38 | * specifies authorized uses of the imported key, such as whether user authentication is required |
| 39 | * for using the key, what operations the key is authorized for (e.g., decryption, but not signing) |
Trevor Johns | 682c24e | 2016-04-12 10:13:47 -0700 | [diff] [blame] | 40 | * with what parameters (e.g., only with a particular padding scheme or digest), and the key's |
Alex Klyubin | 72245d7 | 2015-08-11 06:41:13 -0700 | [diff] [blame] | 41 | * validity start and end dates. Key use authorizations expressed in this class apply only to secret |
| 42 | * keys and private keys -- public keys can be used for any supported operations. |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 43 | * |
Alex Klyubin | 72245d7 | 2015-08-11 06:41:13 -0700 | [diff] [blame] | 44 | * <p>To import a key or key pair into the Android Keystore, create an instance of this class using |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 45 | * the {@link Builder} and pass the instance into {@link java.security.KeyStore#setEntry(String, java.security.KeyStore.Entry, ProtectionParameter) KeyStore.setEntry} |
| 46 | * with the key or key pair being imported. |
| 47 | * |
Alex Klyubin | 72245d7 | 2015-08-11 06:41:13 -0700 | [diff] [blame] | 48 | * <p>To obtain the secret/symmetric or private key from the Android Keystore use |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 49 | * {@link java.security.KeyStore#getKey(String, char[]) KeyStore.getKey(String, null)} or |
| 50 | * {@link java.security.KeyStore#getEntry(String, java.security.KeyStore.ProtectionParameter) KeyStore.getEntry(String, null)}. |
Alex Klyubin | 72245d7 | 2015-08-11 06:41:13 -0700 | [diff] [blame] | 51 | * To obtain the public key from the Android Keystore use |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 52 | * {@link java.security.KeyStore#getCertificate(String)} and then |
| 53 | * {@link Certificate#getPublicKey()}. |
| 54 | * |
Alex Klyubin | 72245d7 | 2015-08-11 06:41:13 -0700 | [diff] [blame] | 55 | * <p>To help obtain algorithm-specific public parameters of key pairs stored in the Android |
| 56 | * Keystore, its private keys implement {@link java.security.interfaces.ECKey} or |
| 57 | * {@link java.security.interfaces.RSAKey} interfaces whereas its public keys implement |
| 58 | * {@link java.security.interfaces.ECPublicKey} or {@link java.security.interfaces.RSAPublicKey} |
| 59 | * interfaces. |
| 60 | * |
| 61 | * <p>NOTE: The key material of keys stored in the Android Keystore is not accessible. |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 62 | * |
Alex Klyubin | cb3bb3f | 2015-06-16 12:31:34 -0700 | [diff] [blame] | 63 | * <p>Instances of this class are immutable. |
| 64 | * |
Trevor Johns | 682c24e | 2016-04-12 10:13:47 -0700 | [diff] [blame] | 65 | * <p><h3>Known issues</h3> |
| 66 | * A known bug in Android 6.0 (API Level 23) causes user authentication-related authorizations to be |
| 67 | * enforced even for public keys. To work around this issue extract the public key material to use |
| 68 | * outside of Android Keystore. For example: |
| 69 | * <pre> {@code |
| 70 | * PublicKey unrestrictedPublicKey = |
| 71 | * KeyFactory.getInstance(publicKey.getAlgorithm()).generatePublic( |
| 72 | * new X509EncodedKeySpec(publicKey.getEncoded())); |
| 73 | * }</pre> |
| 74 | * |
Alex Klyubin | 72245d7 | 2015-08-11 06:41:13 -0700 | [diff] [blame] | 75 | * <p><h3>Example: AES key for encryption/decryption in GCM mode</h3> |
| 76 | * This example illustrates how to import an AES key into the Android KeyStore under alias |
Alex Klyubin | a5e21f0e | 2015-06-17 11:24:45 -0700 | [diff] [blame] | 77 | * {@code key1} authorized to be used only for encryption/decryption in GCM mode with no padding. |
| 78 | * The key must export its key material via {@link Key#getEncoded()} in {@code RAW} format. |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 79 | * <pre> {@code |
| 80 | * SecretKey key = ...; // AES key |
| 81 | * |
| 82 | * KeyStore keyStore = KeyStore.getInstance("AndroidKeyStore"); |
| 83 | * keyStore.load(null); |
| 84 | * keyStore.setEntry( |
| 85 | * "key1", |
| 86 | * new KeyStore.SecretKeyEntry(key), |
| 87 | * new KeyProtection.Builder(KeyProperties.PURPOSE_ENCRYPT | KeyProperties.PURPOSE_DECRYPT) |
Alex Klyubin | a5e21f0e | 2015-06-17 11:24:45 -0700 | [diff] [blame] | 88 | * .setBlockMode(KeyProperties.BLOCK_MODE_GCM) |
| 89 | * .setEncryptionPaddings(KeyProperties.ENCRYPTION_PADDING_NONE) |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 90 | * .build()); |
| 91 | * // Key imported, obtain a reference to it. |
| 92 | * SecretKey keyStoreKey = (SecretKey) keyStore.getKey("key1", null); |
Alex Klyubin | 72245d7 | 2015-08-11 06:41:13 -0700 | [diff] [blame] | 93 | * // The original key can now be discarded. |
| 94 | * |
| 95 | * Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding"); |
| 96 | * cipher.init(Cipher.ENCRYPT_MODE, keyStoreKey); |
| 97 | * ... |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 98 | * }</pre> |
| 99 | * |
Alex Klyubin | 72245d7 | 2015-08-11 06:41:13 -0700 | [diff] [blame] | 100 | * <p><h3>Example: HMAC key for generating MACs using SHA-512</h3> |
| 101 | * This example illustrates how to import an HMAC key into the Android KeyStore under alias |
| 102 | * {@code key1} authorized to be used only for generating MACs using SHA-512 digest. The key must |
| 103 | * export its key material via {@link Key#getEncoded()} in {@code RAW} format. |
| 104 | * <pre> {@code |
| 105 | * SecretKey key = ...; // HMAC key of algorithm "HmacSHA512". |
| 106 | * |
| 107 | * KeyStore keyStore = KeyStore.getInstance("AndroidKeyStore"); |
| 108 | * keyStore.load(null); |
| 109 | * keyStore.setEntry( |
| 110 | * "key1", |
| 111 | * new KeyStore.SecretKeyEntry(key), |
| 112 | * new KeyProtection.Builder(KeyProperties.PURPOSE_SIGN).build()); |
| 113 | * // Key imported, obtain a reference to it. |
| 114 | * SecretKey keyStoreKey = (SecretKey) keyStore.getKey("key1", null); |
| 115 | * // The original key can now be discarded. |
| 116 | * |
| 117 | * Mac mac = Mac.getInstance("HmacSHA512"); |
| 118 | * mac.init(keyStoreKey); |
| 119 | * ... |
| 120 | * }</pre> |
| 121 | * |
| 122 | * <p><h3>Example: EC key pair for signing/verification using ECDSA</h3> |
| 123 | * This example illustrates how to import an EC key pair into the Android KeyStore under alias |
| 124 | * {@code key2} with the private key authorized to be used only for signing with SHA-256 or SHA-512 |
Trevor Johns | 682c24e | 2016-04-12 10:13:47 -0700 | [diff] [blame] | 125 | * digests. The use of the public key is unrestricted. Both the private and the public key must |
| 126 | * export their key material via {@link Key#getEncoded()} in {@code PKCS#8} and {@code X.509} format |
| 127 | * respectively. |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 128 | * <pre> {@code |
| 129 | * PrivateKey privateKey = ...; // EC private key |
| 130 | * Certificate[] certChain = ...; // Certificate chain with the first certificate |
| 131 | * // containing the corresponding EC public key. |
| 132 | * |
| 133 | * KeyStore keyStore = KeyStore.getInstance("AndroidKeyStore"); |
| 134 | * keyStore.load(null); |
| 135 | * keyStore.setEntry( |
| 136 | * "key2", |
| 137 | * new KeyStore.PrivateKeyEntry(privateKey, certChain), |
| 138 | * new KeyProtection.Builder(KeyProperties.PURPOSE_SIGN) |
Alex Klyubin | 72245d7 | 2015-08-11 06:41:13 -0700 | [diff] [blame] | 139 | * .setDigests(KeyProperties.DIGEST_SHA256, KeyProperties.DIGEST_SHA512) |
| 140 | * .build()); |
| 141 | * // Key pair imported, obtain a reference to it. |
| 142 | * PrivateKey keyStorePrivateKey = (PrivateKey) keyStore.getKey("key2", null); |
| 143 | * PublicKey publicKey = keyStore.getCertificate("key2").getPublicKey(); |
| 144 | * // The original private key can now be discarded. |
| 145 | * |
| 146 | * Signature signature = Signature.getInstance("SHA256withECDSA"); |
| 147 | * signature.initSign(keyStorePrivateKey); |
| 148 | * ... |
| 149 | * }</pre> |
| 150 | * |
| 151 | * <p><h3>Example: RSA key pair for signing/verification using PKCS#1 padding</h3> |
| 152 | * This example illustrates how to import an RSA key pair into the Android KeyStore under alias |
| 153 | * {@code key2} with the private key authorized to be used only for signing using the PKCS#1 |
| 154 | * signature padding scheme with SHA-256 digest and only if the user has been authenticated within |
Trevor Johns | 682c24e | 2016-04-12 10:13:47 -0700 | [diff] [blame] | 155 | * the last ten minutes. The use of the public key is unrestricted (see Known Issues). Both the |
Alex Klyubin | 72245d7 | 2015-08-11 06:41:13 -0700 | [diff] [blame] | 156 | * private and the public key must export their key material via {@link Key#getEncoded()} in |
| 157 | * {@code PKCS#8} and {@code X.509} format respectively. |
| 158 | * <pre> {@code |
| 159 | * PrivateKey privateKey = ...; // RSA private key |
| 160 | * Certificate[] certChain = ...; // Certificate chain with the first certificate |
| 161 | * // containing the corresponding RSA public key. |
| 162 | * |
| 163 | * KeyStore keyStore = KeyStore.getInstance("AndroidKeyStore"); |
| 164 | * keyStore.load(null); |
| 165 | * keyStore.setEntry( |
| 166 | * "key2", |
| 167 | * new KeyStore.PrivateKeyEntry(privateKey, certChain), |
| 168 | * new KeyProtection.Builder(KeyProperties.PURPOSE_SIGN) |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 169 | * .setDigests(KeyProperties.DIGEST_SHA256) |
Alex Klyubin | 72245d7 | 2015-08-11 06:41:13 -0700 | [diff] [blame] | 170 | * .setSignaturePaddings(KeyProperties.SIGNATURE_PADDING_RSA_PKCS1) |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 171 | * // Only permit this key to be used if the user |
| 172 | * // authenticated within the last ten minutes. |
| 173 | * .setUserAuthenticationRequired(true) |
| 174 | * .setUserAuthenticationValidityDurationSeconds(10 * 60) |
| 175 | * .build()); |
| 176 | * // Key pair imported, obtain a reference to it. |
| 177 | * PrivateKey keyStorePrivateKey = (PrivateKey) keyStore.getKey("key2", null); |
| 178 | * PublicKey publicKey = keyStore.getCertificate("key2").getPublicKey(); |
Alex Klyubin | 72245d7 | 2015-08-11 06:41:13 -0700 | [diff] [blame] | 179 | * // The original private key can now be discarded. |
| 180 | * |
| 181 | * Signature signature = Signature.getInstance("SHA256withRSA"); |
| 182 | * signature.initSign(keyStorePrivateKey); |
| 183 | * ... |
| 184 | * }</pre> |
| 185 | * |
| 186 | * <p><h3>Example: RSA key pair for encryption/decryption using PKCS#1 padding</h3> |
| 187 | * This example illustrates how to import an RSA key pair into the Android KeyStore under alias |
| 188 | * {@code key2} with the private key authorized to be used only for decryption using the PKCS#1 |
| 189 | * encryption padding scheme. The use of public key is unrestricted, thus permitting encryption |
| 190 | * using any padding schemes and digests. Both the private and the public key must export their key |
| 191 | * material via {@link Key#getEncoded()} in {@code PKCS#8} and {@code X.509} format respectively. |
| 192 | * <pre> {@code |
| 193 | * PrivateKey privateKey = ...; // RSA private key |
| 194 | * Certificate[] certChain = ...; // Certificate chain with the first certificate |
| 195 | * // containing the corresponding RSA public key. |
| 196 | * |
| 197 | * KeyStore keyStore = KeyStore.getInstance("AndroidKeyStore"); |
| 198 | * keyStore.load(null); |
| 199 | * keyStore.setEntry( |
| 200 | * "key2", |
| 201 | * new KeyStore.PrivateKeyEntry(privateKey, certChain), |
| 202 | * new KeyProtection.Builder(KeyProperties.PURPOSE_DECRYPT) |
| 203 | * .setEncryptionPaddings(KeyProperties.ENCRYPTION_PADDING_RSA_PKCS1) |
| 204 | * .build()); |
| 205 | * // Key pair imported, obtain a reference to it. |
| 206 | * PrivateKey keyStorePrivateKey = (PrivateKey) keyStore.getKey("key2", null); |
| 207 | * PublicKey publicKey = keyStore.getCertificate("key2").getPublicKey(); |
| 208 | * // The original private key can now be discarded. |
| 209 | * |
| 210 | * Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding"); |
| 211 | * cipher.init(Cipher.DECRYPT_MODE, keyStorePrivateKey); |
| 212 | * ... |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 213 | * }</pre> |
| 214 | */ |
| 215 | public final class KeyProtection implements ProtectionParameter { |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 216 | private final Date mKeyValidityStart; |
| 217 | private final Date mKeyValidityForOriginationEnd; |
| 218 | private final Date mKeyValidityForConsumptionEnd; |
| 219 | private final @KeyProperties.PurposeEnum int mPurposes; |
| 220 | private final @KeyProperties.EncryptionPaddingEnum String[] mEncryptionPaddings; |
| 221 | private final @KeyProperties.SignaturePaddingEnum String[] mSignaturePaddings; |
| 222 | private final @KeyProperties.DigestEnum String[] mDigests; |
| 223 | private final @KeyProperties.BlockModeEnum String[] mBlockModes; |
| 224 | private final boolean mRandomizedEncryptionRequired; |
| 225 | private final boolean mUserAuthenticationRequired; |
| 226 | private final int mUserAuthenticationValidityDurationSeconds; |
Shawn Willden | adef496 | 2016-01-29 07:07:16 -0700 | [diff] [blame] | 227 | private final boolean mUserAuthenticationValidWhileOnBody; |
Shawn Willden | c38eae5 | 2016-02-22 23:28:34 +0000 | [diff] [blame] | 228 | private final boolean mInvalidatedByBiometricEnrollment; |
Rubin Xu | 59ced28 | 2017-01-30 23:39:12 +0000 | [diff] [blame] | 229 | private final long mBoundToSecureUserId; |
Rubin Xu | 12b644d | 2017-04-21 19:21:42 +0100 | [diff] [blame] | 230 | private final boolean mCriticalToDeviceEncryption; |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 231 | |
| 232 | private KeyProtection( |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 233 | Date keyValidityStart, |
| 234 | Date keyValidityForOriginationEnd, |
| 235 | Date keyValidityForConsumptionEnd, |
| 236 | @KeyProperties.PurposeEnum int purposes, |
| 237 | @KeyProperties.EncryptionPaddingEnum String[] encryptionPaddings, |
| 238 | @KeyProperties.SignaturePaddingEnum String[] signaturePaddings, |
| 239 | @KeyProperties.DigestEnum String[] digests, |
| 240 | @KeyProperties.BlockModeEnum String[] blockModes, |
| 241 | boolean randomizedEncryptionRequired, |
| 242 | boolean userAuthenticationRequired, |
Shawn Willden | adef496 | 2016-01-29 07:07:16 -0700 | [diff] [blame] | 243 | int userAuthenticationValidityDurationSeconds, |
Shawn Willden | c38eae5 | 2016-02-22 23:28:34 +0000 | [diff] [blame] | 244 | boolean userAuthenticationValidWhileOnBody, |
Rubin Xu | 59ced28 | 2017-01-30 23:39:12 +0000 | [diff] [blame] | 245 | boolean invalidatedByBiometricEnrollment, |
Rubin Xu | 12b644d | 2017-04-21 19:21:42 +0100 | [diff] [blame] | 246 | long boundToSecureUserId, |
| 247 | boolean criticalToDeviceEncryption) { |
Alex Klyubin | cb3bb3f | 2015-06-16 12:31:34 -0700 | [diff] [blame] | 248 | mKeyValidityStart = Utils.cloneIfNotNull(keyValidityStart); |
| 249 | mKeyValidityForOriginationEnd = Utils.cloneIfNotNull(keyValidityForOriginationEnd); |
| 250 | mKeyValidityForConsumptionEnd = Utils.cloneIfNotNull(keyValidityForConsumptionEnd); |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 251 | mPurposes = purposes; |
| 252 | mEncryptionPaddings = |
| 253 | ArrayUtils.cloneIfNotEmpty(ArrayUtils.nullToEmpty(encryptionPaddings)); |
| 254 | mSignaturePaddings = |
| 255 | ArrayUtils.cloneIfNotEmpty(ArrayUtils.nullToEmpty(signaturePaddings)); |
| 256 | mDigests = ArrayUtils.cloneIfNotEmpty(digests); |
| 257 | mBlockModes = ArrayUtils.cloneIfNotEmpty(ArrayUtils.nullToEmpty(blockModes)); |
| 258 | mRandomizedEncryptionRequired = randomizedEncryptionRequired; |
| 259 | mUserAuthenticationRequired = userAuthenticationRequired; |
| 260 | mUserAuthenticationValidityDurationSeconds = userAuthenticationValidityDurationSeconds; |
Shawn Willden | adef496 | 2016-01-29 07:07:16 -0700 | [diff] [blame] | 261 | mUserAuthenticationValidWhileOnBody = userAuthenticationValidWhileOnBody; |
Shawn Willden | c38eae5 | 2016-02-22 23:28:34 +0000 | [diff] [blame] | 262 | mInvalidatedByBiometricEnrollment = invalidatedByBiometricEnrollment; |
Rubin Xu | 59ced28 | 2017-01-30 23:39:12 +0000 | [diff] [blame] | 263 | mBoundToSecureUserId = boundToSecureUserId; |
Rubin Xu | 12b644d | 2017-04-21 19:21:42 +0100 | [diff] [blame] | 264 | mCriticalToDeviceEncryption = criticalToDeviceEncryption; |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 265 | } |
| 266 | |
| 267 | /** |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 268 | * Gets the time instant before which the key is not yet valid. |
| 269 | * |
| 270 | * @return instant or {@code null} if not restricted. |
| 271 | */ |
| 272 | @Nullable |
| 273 | public Date getKeyValidityStart() { |
Alex Klyubin | cb3bb3f | 2015-06-16 12:31:34 -0700 | [diff] [blame] | 274 | return Utils.cloneIfNotNull(mKeyValidityStart); |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 275 | } |
| 276 | |
| 277 | /** |
| 278 | * Gets the time instant after which the key is no long valid for decryption and verification. |
| 279 | * |
| 280 | * @return instant or {@code null} if not restricted. |
| 281 | */ |
| 282 | @Nullable |
| 283 | public Date getKeyValidityForConsumptionEnd() { |
Alex Klyubin | cb3bb3f | 2015-06-16 12:31:34 -0700 | [diff] [blame] | 284 | return Utils.cloneIfNotNull(mKeyValidityForConsumptionEnd); |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 285 | } |
| 286 | |
| 287 | /** |
| 288 | * Gets the time instant after which the key is no long valid for encryption and signing. |
| 289 | * |
| 290 | * @return instant or {@code null} if not restricted. |
| 291 | */ |
| 292 | @Nullable |
| 293 | public Date getKeyValidityForOriginationEnd() { |
Alex Klyubin | cb3bb3f | 2015-06-16 12:31:34 -0700 | [diff] [blame] | 294 | return Utils.cloneIfNotNull(mKeyValidityForOriginationEnd); |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 295 | } |
| 296 | |
| 297 | /** |
| 298 | * Gets the set of purposes (e.g., encrypt, decrypt, sign) for which the key can be used. |
| 299 | * Attempts to use the key for any other purpose will be rejected. |
| 300 | * |
| 301 | * <p>See {@link KeyProperties}.{@code PURPOSE} flags. |
| 302 | */ |
| 303 | public @KeyProperties.PurposeEnum int getPurposes() { |
| 304 | return mPurposes; |
| 305 | } |
| 306 | |
| 307 | /** |
| 308 | * Gets the set of padding schemes (e.g., {@code PKCS7Padding}, {@code PKCS1Padding}, |
| 309 | * {@code NoPadding}) with which the key can be used when encrypting/decrypting. Attempts to use |
| 310 | * the key with any other padding scheme will be rejected. |
| 311 | * |
| 312 | * <p>See {@link KeyProperties}.{@code ENCRYPTION_PADDING} constants. |
| 313 | */ |
| 314 | @NonNull |
| 315 | public @KeyProperties.EncryptionPaddingEnum String[] getEncryptionPaddings() { |
| 316 | return ArrayUtils.cloneIfNotEmpty(mEncryptionPaddings); |
| 317 | } |
| 318 | |
| 319 | /** |
| 320 | * Gets the set of padding schemes (e.g., {@code PSS}, {@code PKCS#1}) with which the key |
| 321 | * can be used when signing/verifying. Attempts to use the key with any other padding scheme |
| 322 | * will be rejected. |
| 323 | * |
| 324 | * <p>See {@link KeyProperties}.{@code SIGNATURE_PADDING} constants. |
| 325 | */ |
| 326 | @NonNull |
| 327 | public @KeyProperties.SignaturePaddingEnum String[] getSignaturePaddings() { |
| 328 | return ArrayUtils.cloneIfNotEmpty(mSignaturePaddings); |
| 329 | } |
| 330 | |
| 331 | /** |
| 332 | * Gets the set of digest algorithms (e.g., {@code SHA-256}, {@code SHA-384}) with which the key |
| 333 | * can be used. |
| 334 | * |
| 335 | * <p>See {@link KeyProperties}.{@code DIGEST} constants. |
| 336 | * |
| 337 | * @throws IllegalStateException if this set has not been specified. |
| 338 | * |
| 339 | * @see #isDigestsSpecified() |
| 340 | */ |
| 341 | @NonNull |
| 342 | public @KeyProperties.DigestEnum String[] getDigests() { |
| 343 | if (mDigests == null) { |
| 344 | throw new IllegalStateException("Digests not specified"); |
| 345 | } |
| 346 | return ArrayUtils.cloneIfNotEmpty(mDigests); |
| 347 | } |
| 348 | |
| 349 | /** |
| 350 | * Returns {@code true} if the set of digest algorithms with which the key can be used has been |
| 351 | * specified. |
| 352 | * |
| 353 | * @see #getDigests() |
| 354 | */ |
| 355 | public boolean isDigestsSpecified() { |
| 356 | return mDigests != null; |
| 357 | } |
| 358 | |
| 359 | /** |
Alex Klyubin | a5e21f0e | 2015-06-17 11:24:45 -0700 | [diff] [blame] | 360 | * Gets the set of block modes (e.g., {@code GCM}, {@code CBC}) with which the key can be used |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 361 | * when encrypting/decrypting. Attempts to use the key with any other block modes will be |
| 362 | * rejected. |
| 363 | * |
| 364 | * <p>See {@link KeyProperties}.{@code BLOCK_MODE} constants. |
| 365 | */ |
| 366 | @NonNull |
| 367 | public @KeyProperties.BlockModeEnum String[] getBlockModes() { |
| 368 | return ArrayUtils.cloneIfNotEmpty(mBlockModes); |
| 369 | } |
| 370 | |
| 371 | /** |
| 372 | * Returns {@code true} if encryption using this key must be sufficiently randomized to produce |
| 373 | * different ciphertexts for the same plaintext every time. The formal cryptographic property |
| 374 | * being required is <em>indistinguishability under chosen-plaintext attack ({@code |
| 375 | * IND-CPA})</em>. This property is important because it mitigates several classes of |
| 376 | * weaknesses due to which ciphertext may leak information about plaintext. For example, if a |
| 377 | * given plaintext always produces the same ciphertext, an attacker may see the repeated |
| 378 | * ciphertexts and be able to deduce something about the plaintext. |
| 379 | */ |
| 380 | public boolean isRandomizedEncryptionRequired() { |
| 381 | return mRandomizedEncryptionRequired; |
| 382 | } |
| 383 | |
| 384 | /** |
Alex Klyubin | 83cc7a3 | 2015-06-16 10:44:11 -0700 | [diff] [blame] | 385 | * Returns {@code true} if the key is authorized to be used only if the user has been |
| 386 | * authenticated. |
| 387 | * |
| 388 | * <p>This authorization applies only to secret key and private key operations. Public key |
| 389 | * operations are not restricted. |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 390 | * |
| 391 | * @see #getUserAuthenticationValidityDurationSeconds() |
Alex Klyubin | 83cc7a3 | 2015-06-16 10:44:11 -0700 | [diff] [blame] | 392 | * @see Builder#setUserAuthenticationRequired(boolean) |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 393 | */ |
| 394 | public boolean isUserAuthenticationRequired() { |
| 395 | return mUserAuthenticationRequired; |
| 396 | } |
| 397 | |
| 398 | /** |
Alex Klyubin | 83cc7a3 | 2015-06-16 10:44:11 -0700 | [diff] [blame] | 399 | * Gets the duration of time (seconds) for which this key is authorized to be used after the |
| 400 | * user is successfully authenticated. This has effect only if user authentication is required |
| 401 | * (see {@link #isUserAuthenticationRequired()}). |
| 402 | * |
| 403 | * <p>This authorization applies only to secret key and private key operations. Public key |
| 404 | * operations are not restricted. |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 405 | * |
| 406 | * @return duration in seconds or {@code -1} if authentication is required for every use of the |
| 407 | * key. |
| 408 | * |
| 409 | * @see #isUserAuthenticationRequired() |
Alex Klyubin | 83cc7a3 | 2015-06-16 10:44:11 -0700 | [diff] [blame] | 410 | * @see Builder#setUserAuthenticationValidityDurationSeconds(int) |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 411 | */ |
| 412 | public int getUserAuthenticationValidityDurationSeconds() { |
| 413 | return mUserAuthenticationValidityDurationSeconds; |
| 414 | } |
| 415 | |
| 416 | /** |
Shawn Willden | 26e8d55 | 2016-06-14 17:27:10 -0600 | [diff] [blame] | 417 | * Returns {@code true} if the key will be de-authorized when the device is removed from the |
| 418 | * user's body. This option has no effect on keys that don't have an authentication validity |
| 419 | * duration, and has no effect if the device lacks an on-body sensor. |
Shawn Willden | adef496 | 2016-01-29 07:07:16 -0700 | [diff] [blame] | 420 | * |
| 421 | * <p>Authorization applies only to secret key and private key operations. Public key operations |
| 422 | * are not restricted. |
| 423 | * |
| 424 | * @see #isUserAuthenticationRequired() |
| 425 | * @see #getUserAuthenticationValidityDurationSeconds() |
| 426 | * @see Builder#setUserAuthenticationValidWhileOnBody(boolean) |
| 427 | */ |
| 428 | public boolean isUserAuthenticationValidWhileOnBody() { |
| 429 | return mUserAuthenticationValidWhileOnBody; |
| 430 | } |
| 431 | |
| 432 | /** |
Shawn Willden | c38eae5 | 2016-02-22 23:28:34 +0000 | [diff] [blame] | 433 | * Returns {@code true} if the key is irreversibly invalidated when a new fingerprint is |
| 434 | * enrolled or all enrolled fingerprints are removed. This has effect only for keys that |
| 435 | * require fingerprint user authentication for every use. |
| 436 | * |
| 437 | * @see #isUserAuthenticationRequired() |
| 438 | * @see #getUserAuthenticationValidityDurationSeconds() |
| 439 | * @see Builder#setInvalidatedByBiometricEnrollment(boolean) |
| 440 | */ |
| 441 | public boolean isInvalidatedByBiometricEnrollment() { |
| 442 | return mInvalidatedByBiometricEnrollment; |
| 443 | } |
| 444 | |
| 445 | /** |
Rubin Xu | 59ced28 | 2017-01-30 23:39:12 +0000 | [diff] [blame] | 446 | * Return the secure user id that this key should be bound to. |
| 447 | * |
| 448 | * Normally an authentication-bound key is tied to the secure user id of the current user |
| 449 | * (either the root SID from GateKeeper for auth-bound keys with a timeout, or the authenticator |
| 450 | * id of the current fingerprint set for keys requiring explicit fingerprint authorization). |
| 451 | * If this parameter is set (this method returning non-zero value), the key should be tied to |
| 452 | * the specified secure user id, overriding the logic above. |
| 453 | * |
| 454 | * This is only applicable when {@link #isUserAuthenticationRequired} is {@code true} |
| 455 | * |
| 456 | * @see KeymasterUtils#addUserAuthArgs |
| 457 | * @hide |
| 458 | */ |
| 459 | public long getBoundToSpecificSecureUserId() { |
| 460 | return mBoundToSecureUserId; |
| 461 | } |
| 462 | |
| 463 | /** |
Rubin Xu | 12b644d | 2017-04-21 19:21:42 +0100 | [diff] [blame] | 464 | * Return whether this key is critical to the device encryption flow. |
| 465 | * |
| 466 | * @see android.security.KeyStore#FLAG_CRITICAL_TO_DEVICE_ENCRYPTION |
| 467 | * @hide |
| 468 | */ |
| 469 | public boolean isCriticalToDeviceEncryption() { |
| 470 | return mCriticalToDeviceEncryption; |
| 471 | } |
| 472 | |
| 473 | /** |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 474 | * Builder of {@link KeyProtection} instances. |
| 475 | */ |
| 476 | public final static class Builder { |
| 477 | private @KeyProperties.PurposeEnum int mPurposes; |
| 478 | |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 479 | private Date mKeyValidityStart; |
| 480 | private Date mKeyValidityForOriginationEnd; |
| 481 | private Date mKeyValidityForConsumptionEnd; |
| 482 | private @KeyProperties.EncryptionPaddingEnum String[] mEncryptionPaddings; |
| 483 | private @KeyProperties.SignaturePaddingEnum String[] mSignaturePaddings; |
| 484 | private @KeyProperties.DigestEnum String[] mDigests; |
| 485 | private @KeyProperties.BlockModeEnum String[] mBlockModes; |
| 486 | private boolean mRandomizedEncryptionRequired = true; |
| 487 | private boolean mUserAuthenticationRequired; |
| 488 | private int mUserAuthenticationValidityDurationSeconds = -1; |
Shawn Willden | adef496 | 2016-01-29 07:07:16 -0700 | [diff] [blame] | 489 | private boolean mUserAuthenticationValidWhileOnBody; |
Shawn Willden | c38eae5 | 2016-02-22 23:28:34 +0000 | [diff] [blame] | 490 | private boolean mInvalidatedByBiometricEnrollment = true; |
Rubin Xu | 59ced28 | 2017-01-30 23:39:12 +0000 | [diff] [blame] | 491 | private long mBoundToSecureUserId = GateKeeper.INVALID_SECURE_USER_ID; |
Rubin Xu | 12b644d | 2017-04-21 19:21:42 +0100 | [diff] [blame] | 492 | private boolean mCriticalToDeviceEncryption = false; |
Frank Salim | 21d9c1d | 2017-12-19 22:38:09 -0800 | [diff] [blame^] | 493 | |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 494 | /** |
| 495 | * Creates a new instance of the {@code Builder}. |
| 496 | * |
| 497 | * @param purposes set of purposes (e.g., encrypt, decrypt, sign) for which the key can be |
| 498 | * used. Attempts to use the key for any other purpose will be rejected. |
| 499 | * |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 500 | * <p>See {@link KeyProperties}.{@code PURPOSE} flags. |
| 501 | */ |
| 502 | public Builder(@KeyProperties.PurposeEnum int purposes) { |
| 503 | mPurposes = purposes; |
| 504 | } |
| 505 | |
| 506 | /** |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 507 | * Sets the time instant before which the key is not yet valid. |
| 508 | * |
| 509 | * <p>By default, the key is valid at any instant. |
| 510 | * |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 511 | * @see #setKeyValidityEnd(Date) |
| 512 | */ |
| 513 | @NonNull |
| 514 | public Builder setKeyValidityStart(Date startDate) { |
Alex Klyubin | cb3bb3f | 2015-06-16 12:31:34 -0700 | [diff] [blame] | 515 | mKeyValidityStart = Utils.cloneIfNotNull(startDate); |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 516 | return this; |
| 517 | } |
| 518 | |
| 519 | /** |
| 520 | * Sets the time instant after which the key is no longer valid. |
| 521 | * |
| 522 | * <p>By default, the key is valid at any instant. |
| 523 | * |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 524 | * @see #setKeyValidityStart(Date) |
| 525 | * @see #setKeyValidityForConsumptionEnd(Date) |
| 526 | * @see #setKeyValidityForOriginationEnd(Date) |
| 527 | */ |
| 528 | @NonNull |
| 529 | public Builder setKeyValidityEnd(Date endDate) { |
| 530 | setKeyValidityForOriginationEnd(endDate); |
| 531 | setKeyValidityForConsumptionEnd(endDate); |
| 532 | return this; |
| 533 | } |
| 534 | |
| 535 | /** |
| 536 | * Sets the time instant after which the key is no longer valid for encryption and signing. |
| 537 | * |
| 538 | * <p>By default, the key is valid at any instant. |
| 539 | * |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 540 | * @see #setKeyValidityForConsumptionEnd(Date) |
| 541 | */ |
| 542 | @NonNull |
| 543 | public Builder setKeyValidityForOriginationEnd(Date endDate) { |
Alex Klyubin | cb3bb3f | 2015-06-16 12:31:34 -0700 | [diff] [blame] | 544 | mKeyValidityForOriginationEnd = Utils.cloneIfNotNull(endDate); |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 545 | return this; |
| 546 | } |
| 547 | |
| 548 | /** |
| 549 | * Sets the time instant after which the key is no longer valid for decryption and |
| 550 | * verification. |
| 551 | * |
| 552 | * <p>By default, the key is valid at any instant. |
| 553 | * |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 554 | * @see #setKeyValidityForOriginationEnd(Date) |
| 555 | */ |
| 556 | @NonNull |
| 557 | public Builder setKeyValidityForConsumptionEnd(Date endDate) { |
Alex Klyubin | cb3bb3f | 2015-06-16 12:31:34 -0700 | [diff] [blame] | 558 | mKeyValidityForConsumptionEnd = Utils.cloneIfNotNull(endDate); |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 559 | return this; |
| 560 | } |
| 561 | |
| 562 | /** |
| 563 | * Sets the set of padding schemes (e.g., {@code OAEPPadding}, {@code PKCS7Padding}, |
| 564 | * {@code NoPadding}) with which the key can be used when encrypting/decrypting. Attempts to |
| 565 | * use the key with any other padding scheme will be rejected. |
| 566 | * |
| 567 | * <p>This must be specified for keys which are used for encryption/decryption. |
| 568 | * |
Alex Klyubin | dcf3d35 | 2015-06-11 14:44:46 -0700 | [diff] [blame] | 569 | * <p>For RSA private keys used by TLS/SSL servers to authenticate themselves to clients it |
| 570 | * is usually necessary to authorize the use of no/any padding |
Alex Klyubin | e4928a2 | 2015-07-21 13:38:48 -0700 | [diff] [blame] | 571 | * ({@link KeyProperties#ENCRYPTION_PADDING_NONE}) and/or PKCS#1 encryption padding |
| 572 | * ({@link KeyProperties#ENCRYPTION_PADDING_RSA_PKCS1}). This is because RSA decryption is |
Alex Klyubin | dcf3d35 | 2015-06-11 14:44:46 -0700 | [diff] [blame] | 573 | * required by some cipher suites, and some stacks request decryption using no padding |
| 574 | * whereas others request PKCS#1 padding. |
| 575 | * |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 576 | * <p>See {@link KeyProperties}.{@code ENCRYPTION_PADDING} constants. |
| 577 | */ |
| 578 | @NonNull |
| 579 | public Builder setEncryptionPaddings( |
| 580 | @KeyProperties.EncryptionPaddingEnum String... paddings) { |
| 581 | mEncryptionPaddings = ArrayUtils.cloneIfNotEmpty(paddings); |
| 582 | return this; |
| 583 | } |
| 584 | |
| 585 | /** |
| 586 | * Sets the set of padding schemes (e.g., {@code PSS}, {@code PKCS#1}) with which the key |
| 587 | * can be used when signing/verifying. Attempts to use the key with any other padding scheme |
| 588 | * will be rejected. |
| 589 | * |
| 590 | * <p>This must be specified for RSA keys which are used for signing/verification. |
| 591 | * |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 592 | * <p>See {@link KeyProperties}.{@code SIGNATURE_PADDING} constants. |
| 593 | */ |
| 594 | @NonNull |
| 595 | public Builder setSignaturePaddings( |
| 596 | @KeyProperties.SignaturePaddingEnum String... paddings) { |
| 597 | mSignaturePaddings = ArrayUtils.cloneIfNotEmpty(paddings); |
| 598 | return this; |
| 599 | } |
| 600 | |
| 601 | /** |
| 602 | * Sets the set of digest algorithms (e.g., {@code SHA-256}, {@code SHA-384}) with which the |
Alex Klyubin | 3867709 | 2015-06-22 13:42:46 -0700 | [diff] [blame] | 603 | * key can be used. Attempts to use the key with any other digest algorithm will be |
| 604 | * rejected. |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 605 | * |
Alex Klyubin | 3867709 | 2015-06-22 13:42:46 -0700 | [diff] [blame] | 606 | * <p>This must be specified for signing/verification keys and RSA encryption/decryption |
| 607 | * keys used with RSA OAEP padding scheme because these operations involve a digest. For |
| 608 | * HMAC keys, the default is the digest specified in {@link Key#getAlgorithm()} (e.g., |
Alex Klyubin | c58153b | 2015-07-08 09:31:23 -0700 | [diff] [blame] | 609 | * {@code SHA-256} for key algorithm {@code HmacSHA256}). HMAC keys cannot be authorized |
| 610 | * for more than one digest. |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 611 | * |
Alex Klyubin | dcf3d35 | 2015-06-11 14:44:46 -0700 | [diff] [blame] | 612 | * <p>For private keys used for TLS/SSL client or server authentication it is usually |
| 613 | * necessary to authorize the use of no digest ({@link KeyProperties#DIGEST_NONE}). This is |
| 614 | * because TLS/SSL stacks typically generate the necessary digest(s) themselves and then use |
| 615 | * a private key to sign it. |
| 616 | * |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 617 | * <p>See {@link KeyProperties}.{@code DIGEST} constants. |
| 618 | */ |
| 619 | @NonNull |
| 620 | public Builder setDigests(@KeyProperties.DigestEnum String... digests) { |
| 621 | mDigests = ArrayUtils.cloneIfNotEmpty(digests); |
| 622 | return this; |
| 623 | } |
| 624 | |
| 625 | /** |
Alex Klyubin | a5e21f0e | 2015-06-17 11:24:45 -0700 | [diff] [blame] | 626 | * Sets the set of block modes (e.g., {@code GCM}, {@code CBC}) with which the key can be |
| 627 | * used when encrypting/decrypting. Attempts to use the key with any other block modes will |
| 628 | * be rejected. |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 629 | * |
Alex Klyubin | a5e21f0e | 2015-06-17 11:24:45 -0700 | [diff] [blame] | 630 | * <p>This must be specified for symmetric encryption/decryption keys. |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 631 | * |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 632 | * <p>See {@link KeyProperties}.{@code BLOCK_MODE} constants. |
| 633 | */ |
| 634 | @NonNull |
| 635 | public Builder setBlockModes(@KeyProperties.BlockModeEnum String... blockModes) { |
| 636 | mBlockModes = ArrayUtils.cloneIfNotEmpty(blockModes); |
| 637 | return this; |
| 638 | } |
| 639 | |
| 640 | /** |
| 641 | * Sets whether encryption using this key must be sufficiently randomized to produce |
| 642 | * different ciphertexts for the same plaintext every time. The formal cryptographic |
| 643 | * property being required is <em>indistinguishability under chosen-plaintext attack |
| 644 | * ({@code IND-CPA})</em>. This property is important because it mitigates several classes |
| 645 | * of weaknesses due to which ciphertext may leak information about plaintext. For example, |
| 646 | * if a given plaintext always produces the same ciphertext, an attacker may see the |
| 647 | * repeated ciphertexts and be able to deduce something about the plaintext. |
| 648 | * |
| 649 | * <p>By default, {@code IND-CPA} is required. |
| 650 | * |
| 651 | * <p>When {@code IND-CPA} is required: |
| 652 | * <ul> |
| 653 | * <li>transformation which do not offer {@code IND-CPA}, such as symmetric ciphers using |
| 654 | * {@code ECB} mode or RSA encryption without padding, are prohibited;</li> |
Alex Klyubin | a5e21f0e | 2015-06-17 11:24:45 -0700 | [diff] [blame] | 655 | * <li>in transformations which use an IV, such as symmetric ciphers in {@code GCM}, |
| 656 | * {@code CBC}, and {@code CTR} block modes, caller-provided IVs are rejected when |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 657 | * encrypting, to ensure that only random IVs are used.</li> |
| 658 | * |
| 659 | * <p>Before disabling this requirement, consider the following approaches instead: |
| 660 | * <ul> |
| 661 | * <li>If you are generating a random IV for encryption and then initializing a {@code} |
| 662 | * Cipher using the IV, the solution is to let the {@code Cipher} generate a random IV |
| 663 | * instead. This will occur if the {@code Cipher} is initialized for encryption without an |
| 664 | * IV. The IV can then be queried via {@link Cipher#getIV()}.</li> |
| 665 | * <li>If you are generating a non-random IV (e.g., an IV derived from something not fully |
| 666 | * random, such as the name of the file being encrypted, or transaction ID, or password, |
| 667 | * or a device identifier), consider changing your design to use a random IV which will then |
| 668 | * be provided in addition to the ciphertext to the entities which need to decrypt the |
| 669 | * ciphertext.</li> |
| 670 | * <li>If you are using RSA encryption without padding, consider switching to padding |
| 671 | * schemes which offer {@code IND-CPA}, such as PKCS#1 or OAEP.</li> |
| 672 | * </ul> |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 673 | */ |
| 674 | @NonNull |
| 675 | public Builder setRandomizedEncryptionRequired(boolean required) { |
| 676 | mRandomizedEncryptionRequired = required; |
| 677 | return this; |
| 678 | } |
| 679 | |
| 680 | /** |
Alex Klyubin | 83cc7a3 | 2015-06-16 10:44:11 -0700 | [diff] [blame] | 681 | * Sets whether this key is authorized to be used only if the user has been authenticated. |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 682 | * |
Alex Klyubin | 83cc7a3 | 2015-06-16 10:44:11 -0700 | [diff] [blame] | 683 | * <p>By default, the key is authorized to be used regardless of whether the user has been |
| 684 | * authenticated. |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 685 | * |
Alex Klyubin | 83cc7a3 | 2015-06-16 10:44:11 -0700 | [diff] [blame] | 686 | * <p>When user authentication is required: |
| 687 | * <ul> |
| 688 | * <li>The key can only be import if secure lock screen is set up (see |
| 689 | * {@link KeyguardManager#isDeviceSecure()}). Additionally, if the key requires that user |
| 690 | * authentication takes place for every use of the key (see |
| 691 | * {@link #setUserAuthenticationValidityDurationSeconds(int)}), at least one fingerprint |
| 692 | * must be enrolled (see {@link FingerprintManager#hasEnrolledFingerprints()}).</li> |
| 693 | * <li>The use of the key must be authorized by the user by authenticating to this Android |
| 694 | * device using a subset of their secure lock screen credentials such as |
| 695 | * password/PIN/pattern or fingerprint. |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 696 | * <a href="{@docRoot}training/articles/keystore.html#UserAuthentication">More |
| 697 | * information</a>. |
Alex Klyubin | 83cc7a3 | 2015-06-16 10:44:11 -0700 | [diff] [blame] | 698 | * <li>The key will become <em>irreversibly invalidated</em> once the secure lock screen is |
| 699 | * disabled (reconfigured to None, Swipe or other mode which does not authenticate the user) |
| 700 | * or when the secure lock screen is forcibly reset (e.g., by a Device Administrator). |
| 701 | * Additionally, if the key requires that user authentication takes place for every use of |
| 702 | * the key, it is also irreversibly invalidated once a new fingerprint is enrolled or once\ |
Shawn Willden | c38eae5 | 2016-02-22 23:28:34 +0000 | [diff] [blame] | 703 | * no more fingerprints are enrolled, unless {@link |
| 704 | * #setInvalidatedByBiometricEnrollment(boolean)} is used to allow validity after |
| 705 | * enrollment. Attempts to initialize cryptographic operations using such keys will throw |
| 706 | * {@link KeyPermanentlyInvalidatedException}.</li> </ul> |
Alex Klyubin | 83cc7a3 | 2015-06-16 10:44:11 -0700 | [diff] [blame] | 707 | * |
| 708 | * <p>This authorization applies only to secret key and private key operations. Public key |
| 709 | * operations are not restricted. |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 710 | * |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 711 | * @see #setUserAuthenticationValidityDurationSeconds(int) |
Alex Klyubin | 83cc7a3 | 2015-06-16 10:44:11 -0700 | [diff] [blame] | 712 | * @see KeyguardManager#isDeviceSecure() |
| 713 | * @see FingerprintManager#hasEnrolledFingerprints() |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 714 | */ |
| 715 | @NonNull |
| 716 | public Builder setUserAuthenticationRequired(boolean required) { |
| 717 | mUserAuthenticationRequired = required; |
| 718 | return this; |
| 719 | } |
| 720 | |
| 721 | /** |
Alex Klyubin | 83cc7a3 | 2015-06-16 10:44:11 -0700 | [diff] [blame] | 722 | * Sets the duration of time (seconds) for which this key is authorized to be used after the |
| 723 | * user is successfully authenticated. This has effect if the key requires user |
| 724 | * authentication for its use (see {@link #setUserAuthenticationRequired(boolean)}). |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 725 | * |
Alex Klyubin | 83cc7a3 | 2015-06-16 10:44:11 -0700 | [diff] [blame] | 726 | * <p>By default, if user authentication is required, it must take place for every use of |
| 727 | * the key. |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 728 | * |
Alex Klyubin | 83cc7a3 | 2015-06-16 10:44:11 -0700 | [diff] [blame] | 729 | * <p>Cryptographic operations involving keys which require user authentication to take |
| 730 | * place for every operation can only use fingerprint authentication. This is achieved by |
| 731 | * initializing a cryptographic operation ({@link Signature}, {@link Cipher}, {@link Mac}) |
| 732 | * with the key, wrapping it into a {@link FingerprintManager.CryptoObject}, invoking |
| 733 | * {@code FingerprintManager.authenticate} with {@code CryptoObject}, and proceeding with |
| 734 | * the cryptographic operation only if the authentication flow succeeds. |
| 735 | * |
| 736 | * <p>Cryptographic operations involving keys which are authorized to be used for a duration |
| 737 | * of time after a successful user authentication event can only use secure lock screen |
| 738 | * authentication. These cryptographic operations will throw |
| 739 | * {@link UserNotAuthenticatedException} during initialization if the user needs to be |
| 740 | * authenticated to proceed. This situation can be resolved by the user unlocking the secure |
| 741 | * lock screen of the Android or by going through the confirm credential flow initiated by |
| 742 | * {@link KeyguardManager#createConfirmDeviceCredentialIntent(CharSequence, CharSequence)}. |
| 743 | * Once resolved, initializing a new cryptographic operation using this key (or any other |
| 744 | * key which is authorized to be used for a fixed duration of time after user |
| 745 | * authentication) should succeed provided the user authentication flow completed |
| 746 | * successfully. |
| 747 | * |
| 748 | * @param seconds duration in seconds or {@code -1} if user authentication must take place |
| 749 | * for every use of the key. |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 750 | * |
| 751 | * @see #setUserAuthenticationRequired(boolean) |
Alex Klyubin | 83cc7a3 | 2015-06-16 10:44:11 -0700 | [diff] [blame] | 752 | * @see FingerprintManager |
| 753 | * @see FingerprintManager.CryptoObject |
| 754 | * @see KeyguardManager |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 755 | */ |
| 756 | @NonNull |
| 757 | public Builder setUserAuthenticationValidityDurationSeconds( |
| 758 | @IntRange(from = -1) int seconds) { |
Alex Klyubin | cb3bb3f | 2015-06-16 12:31:34 -0700 | [diff] [blame] | 759 | if (seconds < -1) { |
| 760 | throw new IllegalArgumentException("seconds must be -1 or larger"); |
| 761 | } |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 762 | mUserAuthenticationValidityDurationSeconds = seconds; |
| 763 | return this; |
| 764 | } |
| 765 | |
| 766 | /** |
Shawn Willden | 26e8d55 | 2016-06-14 17:27:10 -0600 | [diff] [blame] | 767 | * Sets whether the key will remain authorized only until the device is removed from the |
| 768 | * user's body up to the limit of the authentication validity period (see |
| 769 | * {@link #setUserAuthenticationValidityDurationSeconds} and |
| 770 | * {@link #setUserAuthenticationRequired}). Once the device has been removed from the |
| 771 | * user's body, the key will be considered unauthorized and the user will need to |
| 772 | * re-authenticate to use it. For keys without an authentication validity period this |
| 773 | * parameter has no effect. |
Shawn Willden | adef496 | 2016-01-29 07:07:16 -0700 | [diff] [blame] | 774 | * |
Shawn Willden | 26e8d55 | 2016-06-14 17:27:10 -0600 | [diff] [blame] | 775 | * <p>Similarly, on devices that do not have an on-body sensor, this parameter will have no |
| 776 | * effect; the device will always be considered to be "on-body" and the key will therefore |
| 777 | * remain authorized until the validity period ends. |
Shawn Willden | adef496 | 2016-01-29 07:07:16 -0700 | [diff] [blame] | 778 | * |
Shawn Willden | 26e8d55 | 2016-06-14 17:27:10 -0600 | [diff] [blame] | 779 | * @param remainsValid if {@code true}, and if the device supports on-body detection, key |
| 780 | * will be invalidated when the device is removed from the user's body or when the |
| 781 | * authentication validity expires, whichever occurs first. |
Shawn Willden | adef496 | 2016-01-29 07:07:16 -0700 | [diff] [blame] | 782 | */ |
| 783 | @NonNull |
| 784 | public Builder setUserAuthenticationValidWhileOnBody(boolean remainsValid) { |
| 785 | mUserAuthenticationValidWhileOnBody = remainsValid; |
| 786 | return this; |
| 787 | } |
| 788 | |
| 789 | /** |
Shawn Willden | c38eae5 | 2016-02-22 23:28:34 +0000 | [diff] [blame] | 790 | * Sets whether this key should be invalidated on fingerprint enrollment. This |
| 791 | * applies only to keys which require user authentication (see {@link |
| 792 | * #setUserAuthenticationRequired(boolean)}) and if no positive validity duration has been |
| 793 | * set (see {@link #setUserAuthenticationValidityDurationSeconds(int)}, meaning the key is |
| 794 | * valid for fingerprint authentication only. |
| 795 | * |
| 796 | * <p>By default, {@code invalidateKey} is {@code true}, so keys that are valid for |
| 797 | * fingerprint authentication only are <em>irreversibly invalidated</em> when a new |
| 798 | * fingerprint is enrolled, or when all existing fingerprints are deleted. That may be |
| 799 | * changed by calling this method with {@code invalidateKey} set to {@code false}. |
| 800 | * |
| 801 | * <p>Invalidating keys on enrollment of a new finger or unenrollment of all fingers |
| 802 | * improves security by ensuring that an unauthorized person who obtains the password can't |
| 803 | * gain the use of fingerprint-authenticated keys by enrolling their own finger. However, |
| 804 | * invalidating keys makes key-dependent operations impossible, requiring some fallback |
| 805 | * procedure to authenticate the user and set up a new key. |
| 806 | */ |
| 807 | @NonNull |
| 808 | public Builder setInvalidatedByBiometricEnrollment(boolean invalidateKey) { |
| 809 | mInvalidatedByBiometricEnrollment = invalidateKey; |
| 810 | return this; |
| 811 | } |
| 812 | |
| 813 | /** |
Rubin Xu | 59ced28 | 2017-01-30 23:39:12 +0000 | [diff] [blame] | 814 | * Set the secure user id that this key should be bound to. |
| 815 | * |
| 816 | * Normally an authentication-bound key is tied to the secure user id of the current user |
| 817 | * (either the root SID from GateKeeper for auth-bound keys with a timeout, or the |
| 818 | * authenticator id of the current fingerprint set for keys requiring explicit fingerprint |
| 819 | * authorization). If this parameter is set (this method returning non-zero value), the key |
| 820 | * should be tied to the specified secure user id, overriding the logic above. |
| 821 | * |
| 822 | * This is only applicable when {@link #setUserAuthenticationRequired} is set to |
| 823 | * {@code true} |
| 824 | * |
| 825 | * @see KeyProtection#getBoundToSpecificSecureUserId() |
| 826 | * @hide |
| 827 | */ |
| 828 | public Builder setBoundToSpecificSecureUserId(long secureUserId) { |
| 829 | mBoundToSecureUserId = secureUserId; |
| 830 | return this; |
| 831 | } |
| 832 | |
| 833 | /** |
Rubin Xu | 12b644d | 2017-04-21 19:21:42 +0100 | [diff] [blame] | 834 | * Set whether this key is critical to the device encryption flow |
| 835 | * |
| 836 | * This is a special flag only available to system servers to indicate the current key |
| 837 | * is part of the device encryption flow. |
| 838 | * |
| 839 | * @see android.security.KeyStore#FLAG_CRITICAL_TO_DEVICE_ENCRYPTION |
| 840 | * @hide |
| 841 | */ |
| 842 | public Builder setCriticalToDeviceEncryption(boolean critical) { |
| 843 | mCriticalToDeviceEncryption = critical; |
| 844 | return this; |
| 845 | } |
| 846 | |
| 847 | /** |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 848 | * Builds an instance of {@link KeyProtection}. |
| 849 | * |
| 850 | * @throws IllegalArgumentException if a required field is missing |
| 851 | */ |
| 852 | @NonNull |
| 853 | public KeyProtection build() { |
| 854 | return new KeyProtection( |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 855 | mKeyValidityStart, |
| 856 | mKeyValidityForOriginationEnd, |
| 857 | mKeyValidityForConsumptionEnd, |
| 858 | mPurposes, |
| 859 | mEncryptionPaddings, |
| 860 | mSignaturePaddings, |
| 861 | mDigests, |
| 862 | mBlockModes, |
| 863 | mRandomizedEncryptionRequired, |
| 864 | mUserAuthenticationRequired, |
Shawn Willden | adef496 | 2016-01-29 07:07:16 -0700 | [diff] [blame] | 865 | mUserAuthenticationValidityDurationSeconds, |
Shawn Willden | c38eae5 | 2016-02-22 23:28:34 +0000 | [diff] [blame] | 866 | mUserAuthenticationValidWhileOnBody, |
Rubin Xu | 59ced28 | 2017-01-30 23:39:12 +0000 | [diff] [blame] | 867 | mInvalidatedByBiometricEnrollment, |
Rubin Xu | 12b644d | 2017-04-21 19:21:42 +0100 | [diff] [blame] | 868 | mBoundToSecureUserId, |
| 869 | mCriticalToDeviceEncryption); |
Alex Klyubin | 3f8d4d8 | 2015-05-13 09:15:00 -0700 | [diff] [blame] | 870 | } |
| 871 | } |
| 872 | } |