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      1 /*
      2  * Copyright (C) 2009 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;
     18 
     19 import android.content.ActivityNotFoundException;
     20 import android.content.Context;
     21 import android.content.Intent;
     22 import android.util.Log;
     23 
     24 import com.android.org.bouncycastle.util.io.pem.PemObject;
     25 import com.android.org.bouncycastle.util.io.pem.PemReader;
     26 import com.android.org.bouncycastle.util.io.pem.PemWriter;
     27 
     28 import java.io.ByteArrayInputStream;
     29 import java.io.ByteArrayOutputStream;
     30 import java.io.IOException;
     31 import java.io.InputStreamReader;
     32 import java.io.OutputStreamWriter;
     33 import java.io.Reader;
     34 import java.io.Writer;
     35 import java.nio.charset.StandardCharsets;
     36 import java.security.KeyPair;
     37 import java.security.cert.Certificate;
     38 import java.security.cert.CertificateEncodingException;
     39 import java.security.cert.CertificateException;
     40 import java.security.cert.CertificateFactory;
     41 import java.security.cert.X509Certificate;
     42 import java.util.ArrayList;
     43 import java.util.List;
     44 
     45 /**
     46  * {@hide}
     47  */
     48 public class Credentials {
     49     private static final String LOGTAG = "Credentials";
     50 
     51     public static final String INSTALL_ACTION = "android.credentials.INSTALL";
     52 
     53     public static final String INSTALL_AS_USER_ACTION = "android.credentials.INSTALL_AS_USER";
     54 
     55     public static final String UNLOCK_ACTION = "com.android.credentials.UNLOCK";
     56 
     57     /** Key prefix for CA certificates. */
     58     public static final String CA_CERTIFICATE = "CACERT_";
     59 
     60     /** Key prefix for user certificates. */
     61     public static final String USER_CERTIFICATE = "USRCERT_";
     62 
     63     /** Key prefix for user private keys. */
     64     public static final String USER_PRIVATE_KEY = "USRPKEY_";
     65 
     66     /** Key prefix for user secret keys. */
     67     public static final String USER_SECRET_KEY = "USRSKEY_";
     68 
     69     /** Key prefix for VPN. */
     70     public static final String VPN = "VPN_";
     71 
     72     /** Key prefix for WIFI. */
     73     public static final String WIFI = "WIFI_";
     74 
     75     /** Key containing suffix of lockdown VPN profile. */
     76     public static final String LOCKDOWN_VPN = "LOCKDOWN_VPN";
     77 
     78     /** Data type for public keys. */
     79     public static final String EXTRA_PUBLIC_KEY = "KEY";
     80 
     81     /** Data type for private keys. */
     82     public static final String EXTRA_PRIVATE_KEY = "PKEY";
     83 
     84     // historically used by Android
     85     public static final String EXTENSION_CRT = ".crt";
     86     public static final String EXTENSION_P12 = ".p12";
     87     // commonly used on Windows
     88     public static final String EXTENSION_CER = ".cer";
     89     public static final String EXTENSION_PFX = ".pfx";
     90 
     91     /**
     92      * Intent extra: install the certificate bundle as this UID instead of
     93      * system.
     94      */
     95     public static final String EXTRA_INSTALL_AS_UID = "install_as_uid";
     96 
     97     /**
     98      * Intent extra: name for the user's private key.
     99      */
    100     public static final String EXTRA_USER_PRIVATE_KEY_NAME = "user_private_key_name";
    101 
    102     /**
    103      * Intent extra: data for the user's private key in PEM-encoded PKCS#8.
    104      */
    105     public static final String EXTRA_USER_PRIVATE_KEY_DATA = "user_private_key_data";
    106 
    107     /**
    108      * Intent extra: name for the user's certificate.
    109      */
    110     public static final String EXTRA_USER_CERTIFICATE_NAME = "user_certificate_name";
    111 
    112     /**
    113      * Intent extra: data for the user's certificate in PEM-encoded X.509.
    114      */
    115     public static final String EXTRA_USER_CERTIFICATE_DATA = "user_certificate_data";
    116 
    117     /**
    118      * Intent extra: name for CA certificate chain
    119      */
    120     public static final String EXTRA_CA_CERTIFICATES_NAME = "ca_certificates_name";
    121 
    122     /**
    123      * Intent extra: data for CA certificate chain in PEM-encoded X.509.
    124      */
    125     public static final String EXTRA_CA_CERTIFICATES_DATA = "ca_certificates_data";
    126 
    127     /**
    128      * Convert objects to a PEM format which is used for
    129      * CA_CERTIFICATE and USER_CERTIFICATE entries.
    130      */
    131     public static byte[] convertToPem(Certificate... objects)
    132             throws IOException, CertificateEncodingException {
    133         ByteArrayOutputStream bao = new ByteArrayOutputStream();
    134         Writer writer = new OutputStreamWriter(bao, StandardCharsets.US_ASCII);
    135         PemWriter pw = new PemWriter(writer);
    136         for (Certificate o : objects) {
    137             pw.writeObject(new PemObject("CERTIFICATE", o.getEncoded()));
    138         }
    139         pw.close();
    140         return bao.toByteArray();
    141     }
    142     /**
    143      * Convert objects from PEM format, which is used for
    144      * CA_CERTIFICATE and USER_CERTIFICATE entries.
    145      */
    146     public static List<X509Certificate> convertFromPem(byte[] bytes)
    147             throws IOException, CertificateException {
    148         ByteArrayInputStream bai = new ByteArrayInputStream(bytes);
    149         Reader reader = new InputStreamReader(bai, StandardCharsets.US_ASCII);
    150         PemReader pr = new PemReader(reader);
    151 
    152         try {
    153             CertificateFactory cf = CertificateFactory.getInstance("X509");
    154 
    155             List<X509Certificate> result = new ArrayList<X509Certificate>();
    156             PemObject o;
    157             while ((o = pr.readPemObject()) != null) {
    158                 if (o.getType().equals("CERTIFICATE")) {
    159                     Certificate c = cf.generateCertificate(new ByteArrayInputStream(o.getContent()));
    160                     result.add((X509Certificate) c);
    161                 } else {
    162                     throw new IllegalArgumentException("Unknown type " + o.getType());
    163                 }
    164             }
    165             return result;
    166         } finally {
    167             pr.close();
    168         }
    169     }
    170 
    171     private static Credentials singleton;
    172 
    173     public static Credentials getInstance() {
    174         if (singleton == null) {
    175             singleton = new Credentials();
    176         }
    177         return singleton;
    178     }
    179 
    180     public void unlock(Context context) {
    181         try {
    182             Intent intent = new Intent(UNLOCK_ACTION);
    183             context.startActivity(intent);
    184         } catch (ActivityNotFoundException e) {
    185             Log.w(LOGTAG, e.toString());
    186         }
    187     }
    188 
    189     public void install(Context context) {
    190         try {
    191             Intent intent = KeyChain.createInstallIntent();
    192             context.startActivity(intent);
    193         } catch (ActivityNotFoundException e) {
    194             Log.w(LOGTAG, e.toString());
    195         }
    196     }
    197 
    198     public void install(Context context, KeyPair pair) {
    199         try {
    200             Intent intent = KeyChain.createInstallIntent();
    201             intent.putExtra(EXTRA_PRIVATE_KEY, pair.getPrivate().getEncoded());
    202             intent.putExtra(EXTRA_PUBLIC_KEY, pair.getPublic().getEncoded());
    203             context.startActivity(intent);
    204         } catch (ActivityNotFoundException e) {
    205             Log.w(LOGTAG, e.toString());
    206         }
    207     }
    208 
    209     public void install(Context context, String type, byte[] value) {
    210         try {
    211             Intent intent = KeyChain.createInstallIntent();
    212             intent.putExtra(type, value);
    213             context.startActivity(intent);
    214         } catch (ActivityNotFoundException e) {
    215             Log.w(LOGTAG, e.toString());
    216         }
    217     }
    218 
    219     /**
    220      * Delete all types (private key, user certificate, CA certificate) for a
    221      * particular {@code alias}. All three can exist for any given alias.
    222      * Returns {@code true} if the alias no longer contains any types.
    223      */
    224     public static boolean deleteAllTypesForAlias(KeyStore keystore, String alias) {
    225         return deleteAllTypesForAlias(keystore, alias, KeyStore.UID_SELF);
    226     }
    227 
    228     /**
    229      * Delete all types (private key, user certificate, CA certificate) for a
    230      * particular {@code alias}. All three can exist for any given alias.
    231      * Returns {@code true} if the alias no longer contains any types.
    232      */
    233     public static boolean deleteAllTypesForAlias(KeyStore keystore, String alias, int uid) {
    234         /*
    235          * Make sure every type is deleted. There can be all three types, so
    236          * don't use a conditional here.
    237          */
    238         return deletePrivateKeyTypeForAlias(keystore, alias, uid)
    239                 & deleteSecretKeyTypeForAlias(keystore, alias, uid)
    240                 & deleteCertificateTypesForAlias(keystore, alias, uid);
    241     }
    242 
    243     /**
    244      * Delete certificate types (user certificate, CA certificate) for a
    245      * particular {@code alias}. Both can exist for any given alias.
    246      * Returns {@code true} if the alias no longer contains either type.
    247      */
    248     public static boolean deleteCertificateTypesForAlias(KeyStore keystore, String alias) {
    249         return deleteCertificateTypesForAlias(keystore, alias, KeyStore.UID_SELF);
    250     }
    251 
    252     /**
    253      * Delete certificate types (user certificate, CA certificate) for a
    254      * particular {@code alias}. Both can exist for any given alias.
    255      * Returns {@code true} if the alias no longer contains either type.
    256      */
    257     public static boolean deleteCertificateTypesForAlias(KeyStore keystore, String alias, int uid) {
    258         /*
    259          * Make sure every certificate type is deleted. There can be two types,
    260          * so don't use a conditional here.
    261          */
    262         return keystore.delete(Credentials.USER_CERTIFICATE + alias, uid)
    263                 & keystore.delete(Credentials.CA_CERTIFICATE + alias, uid);
    264     }
    265 
    266     /**
    267      * Delete private key for a particular {@code alias}.
    268      * Returns {@code true} if the entry no longer exists.
    269      */
    270     static boolean deletePrivateKeyTypeForAlias(KeyStore keystore, String alias) {
    271         return deletePrivateKeyTypeForAlias(keystore, alias, KeyStore.UID_SELF);
    272     }
    273 
    274     /**
    275      * Delete private key for a particular {@code alias}.
    276      * Returns {@code true} if the entry no longer exists.
    277      */
    278     static boolean deletePrivateKeyTypeForAlias(KeyStore keystore, String alias, int uid) {
    279         return keystore.delete(Credentials.USER_PRIVATE_KEY + alias, uid);
    280     }
    281 
    282     /**
    283      * Delete secret key for a particular {@code alias}.
    284      * Returns {@code true} if the entry no longer exists.
    285      */
    286     public static boolean deleteSecretKeyTypeForAlias(KeyStore keystore, String alias) {
    287         return deleteSecretKeyTypeForAlias(keystore, alias, KeyStore.UID_SELF);
    288     }
    289 
    290     /**
    291      * Delete secret key for a particular {@code alias}.
    292      * Returns {@code true} if the entry no longer exists.
    293      */
    294     public static boolean deleteSecretKeyTypeForAlias(KeyStore keystore, String alias, int uid) {
    295         return keystore.delete(Credentials.USER_SECRET_KEY + alias, uid);
    296     }
    297 }
    298