1 /*
2  * Copyright (C) 2011 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.internal.net;
18 
19 import android.annotation.NonNull;
20 import android.compat.annotation.UnsupportedAppUsage;
21 import android.net.Ikev2VpnProfile;
22 import android.net.PlatformVpnProfile;
23 import android.net.ProxyInfo;
24 import android.net.Uri;
25 import android.os.Build;
26 import android.os.Parcel;
27 import android.os.Parcelable;
28 import android.text.TextUtils;
29 
30 import com.android.internal.annotations.VisibleForTesting;
31 import com.android.net.module.util.ProxyUtils;
32 
33 import java.io.UnsupportedEncodingException;
34 import java.net.InetAddress;
35 import java.net.URLDecoder;
36 import java.net.URLEncoder;
37 import java.nio.charset.StandardCharsets;
38 import java.util.ArrayList;
39 import java.util.Arrays;
40 import java.util.Collections;
41 import java.util.List;
42 import java.util.Objects;
43 
44 /**
45  * Profile storage class for a platform VPN.
46  *
47  * <p>This class supports both the Legacy VPN, as well as application-configurable platform VPNs
48  * (such as IKEv2/IPsec).
49  *
50  * <p>This class is serialized and deserialized via the {@link #encode()} and {@link #decode()}
51  * functions for persistent storage in the Android Keystore. The encoding is entirely custom, but
52  * must be kept for backward compatibility for devices upgrading between Android versions.
53  *
54  * @hide
55  */
56 public final class VpnProfile implements Cloneable, Parcelable {
57     private static final String TAG = "VpnProfile";
58 
59     @VisibleForTesting static final String VALUE_DELIMITER = "\0";
60     @VisibleForTesting static final String LIST_DELIMITER = ",";
61 
62     // Match these constants with R.array.vpn_types.
63     public static final int TYPE_PPTP = 0;
64     public static final int TYPE_L2TP_IPSEC_PSK = 1;
65     public static final int TYPE_L2TP_IPSEC_RSA = 2;
66     public static final int TYPE_IPSEC_XAUTH_PSK = 3;
67     public static final int TYPE_IPSEC_XAUTH_RSA = 4;
68     public static final int TYPE_IPSEC_HYBRID_RSA = 5;
69     public static final int TYPE_IKEV2_IPSEC_USER_PASS = 6;
70     public static final int TYPE_IKEV2_IPSEC_PSK = 7;
71     public static final int TYPE_IKEV2_IPSEC_RSA = 8;
72     public static final int TYPE_MAX = 8;
73 
74     // Match these constants with R.array.vpn_proxy_settings.
75     public static final int PROXY_NONE = 0;
76     public static final int PROXY_MANUAL = 1;
77 
78     private static final String ENCODED_NULL_PROXY_INFO = "\0\0\0\0";
79 
80     /** Default URL encoding. */
81     private static final String DEFAULT_ENCODING = StandardCharsets.UTF_8.name();
82 
83     // Entity fields.
84     @UnsupportedAppUsage
85     public final String key;                                   // -1
86 
87     @UnsupportedAppUsage
88     public String name = "";                                   // 0
89 
90     @UnsupportedAppUsage
91     public int type = TYPE_PPTP;                               // 1
92 
93     @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P, trackingBug = 115609023)
94     public String server = "";                                 // 2
95 
96     @UnsupportedAppUsage
97     public String username = "";                               // 3
98     public String password = "";                               // 4
99     public String dnsServers = "";                             // 5
100     public String searchDomains = "";                          // 6
101     public String routes = "";                                 // 7
102     public boolean mppe = true;                                // 8
103     public String l2tpSecret = "";                             // 9
104     public String ipsecIdentifier = "";                        // 10
105 
106     /**
107      * The RSA private key or pre-shared key used for authentication.
108      *
109      * <p>If areAuthParamsInline is {@code true}, this String will be either:
110      *
111      * <ul>
112      *   <li>If this is an IKEv2 RSA profile: a PKCS#8 encoded {@link java.security.PrivateKey}
113      *   <li>If this is an IKEv2 PSK profile: a string value representing the PSK.
114      * </ul>
115      */
116     public String ipsecSecret = "";                            // 11
117 
118     /**
119      * The RSA certificate to be used for digital signature authentication.
120      *
121      * <p>If areAuthParamsInline is {@code true}, this String will be a pem-encoded {@link
122      * java.security.X509Certificate}
123      */
124     public String ipsecUserCert = "";                          // 12
125 
126     /**
127      * The RSA certificate that should be used to verify the server's end/target certificate.
128      *
129      * <p>If areAuthParamsInline is {@code true}, this String will be a pem-encoded {@link
130      * java.security.X509Certificate}
131      */
132     public String ipsecCaCert = "";                            // 13
133     public String ipsecServerCert = "";                        // 14
134     public ProxyInfo proxy = null;                             // 15~18
135 
136     /**
137      * The list of allowable algorithms.
138      */
139     private List<String> mAllowedAlgorithms = new ArrayList<>(); // 19
140     public boolean isBypassable = false;                         // 20
141     public boolean isMetered = false;                            // 21
142     public int maxMtu = PlatformVpnProfile.MAX_MTU_DEFAULT;      // 22
143     public boolean areAuthParamsInline = false;                  // 23
144     public final boolean isRestrictedToTestNetworks;             // 24
145 
146     // Helper fields.
147     @UnsupportedAppUsage
148     public transient boolean saveLogin = false;
149 
VpnProfile(String key)150     public VpnProfile(String key) {
151         this(key, false);
152     }
153 
VpnProfile(String key, boolean isRestrictedToTestNetworks)154     public VpnProfile(String key, boolean isRestrictedToTestNetworks) {
155         this.key = key;
156         this.isRestrictedToTestNetworks = isRestrictedToTestNetworks;
157     }
158 
159     @UnsupportedAppUsage
VpnProfile(Parcel in)160     public VpnProfile(Parcel in) {
161         key = in.readString();
162         name = in.readString();
163         type = in.readInt();
164         server = in.readString();
165         username = in.readString();
166         password = in.readString();
167         dnsServers = in.readString();
168         searchDomains = in.readString();
169         routes = in.readString();
170         mppe = in.readInt() != 0;
171         l2tpSecret = in.readString();
172         ipsecIdentifier = in.readString();
173         ipsecSecret = in.readString();
174         ipsecUserCert = in.readString();
175         ipsecCaCert = in.readString();
176         ipsecServerCert = in.readString();
177         saveLogin = in.readInt() != 0;
178         proxy = in.readParcelable(null);
179         mAllowedAlgorithms = new ArrayList<>();
180         in.readList(mAllowedAlgorithms, null);
181         isBypassable = in.readBoolean();
182         isMetered = in.readBoolean();
183         maxMtu = in.readInt();
184         areAuthParamsInline = in.readBoolean();
185         isRestrictedToTestNetworks = in.readBoolean();
186     }
187 
188     /**
189      * Retrieves the list of allowed algorithms.
190      *
191      * <p>The contained elements are as listed in {@link IpSecAlgorithm}
192      */
getAllowedAlgorithms()193     public List<String> getAllowedAlgorithms() {
194         return Collections.unmodifiableList(mAllowedAlgorithms);
195     }
196 
197     /**
198      * Validates and sets the list of algorithms that can be used for the IPsec transforms.
199      *
200      * @param allowedAlgorithms the list of allowable algorithms, as listed in {@link
201      *     IpSecAlgorithm}.
202      */
setAllowedAlgorithms(List<String> allowedAlgorithms)203     public void setAllowedAlgorithms(List<String> allowedAlgorithms) {
204         mAllowedAlgorithms = allowedAlgorithms;
205     }
206 
207     @Override
writeToParcel(Parcel out, int flags)208     public void writeToParcel(Parcel out, int flags) {
209         out.writeString(key);
210         out.writeString(name);
211         out.writeInt(type);
212         out.writeString(server);
213         out.writeString(username);
214         out.writeString(password);
215         out.writeString(dnsServers);
216         out.writeString(searchDomains);
217         out.writeString(routes);
218         out.writeInt(mppe ? 1 : 0);
219         out.writeString(l2tpSecret);
220         out.writeString(ipsecIdentifier);
221         out.writeString(ipsecSecret);
222         out.writeString(ipsecUserCert);
223         out.writeString(ipsecCaCert);
224         out.writeString(ipsecServerCert);
225         out.writeInt(saveLogin ? 1 : 0);
226         out.writeParcelable(proxy, flags);
227         out.writeList(mAllowedAlgorithms);
228         out.writeBoolean(isBypassable);
229         out.writeBoolean(isMetered);
230         out.writeInt(maxMtu);
231         out.writeBoolean(areAuthParamsInline);
232         out.writeBoolean(isRestrictedToTestNetworks);
233     }
234 
235     /**
236      * Decodes a VpnProfile instance from the encoded byte array.
237      *
238      * <p>See {@link #encode()}
239      */
240     @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553)
decode(String key, byte[] value)241     public static VpnProfile decode(String key, byte[] value) {
242         try {
243             if (key == null) {
244                 return null;
245             }
246 
247             String[] values = new String(value, StandardCharsets.UTF_8).split(VALUE_DELIMITER, -1);
248             // Acceptable numbers of values are:
249             // 14-19: Standard profile, with option for serverCert, proxy
250             // 24: Standard profile with serverCert, proxy and platform-VPN parameters
251             // 25: Standard profile with platform-VPN parameters and isRestrictedToTestNetworks
252             if ((values.length < 14 || values.length > 19)
253                     && values.length != 24 && values.length != 25) {
254                 return null;
255             }
256 
257             final boolean isRestrictedToTestNetworks;
258             if (values.length >= 25) {
259                 isRestrictedToTestNetworks = Boolean.parseBoolean(values[24]);
260             } else {
261                 isRestrictedToTestNetworks = false;
262             }
263 
264             VpnProfile profile = new VpnProfile(key, isRestrictedToTestNetworks);
265             profile.name = values[0];
266             profile.type = Integer.parseInt(values[1]);
267             if (profile.type < 0 || profile.type > TYPE_MAX) {
268                 return null;
269             }
270             profile.server = values[2];
271             profile.username = values[3];
272             profile.password = values[4];
273             profile.dnsServers = values[5];
274             profile.searchDomains = values[6];
275             profile.routes = values[7];
276             profile.mppe = Boolean.parseBoolean(values[8]);
277             profile.l2tpSecret = values[9];
278             profile.ipsecIdentifier = values[10];
279             profile.ipsecSecret = values[11];
280             profile.ipsecUserCert = values[12];
281             profile.ipsecCaCert = values[13];
282             profile.ipsecServerCert = (values.length > 14) ? values[14] : "";
283             if (values.length > 15) {
284                 String host = (values.length > 15) ? values[15] : "";
285                 String port = (values.length > 16) ? values[16] : "";
286                 String exclList = (values.length > 17) ? values[17] : "";
287                 String pacFileUrl = (values.length > 18) ? values[18] : "";
288                 if (!host.isEmpty() || !port.isEmpty() || !exclList.isEmpty()) {
289                     profile.proxy =
290                             ProxyInfo.buildDirectProxy(host, port.isEmpty() ?
291                                     0 : Integer.parseInt(port),
292                                     ProxyUtils.exclusionStringAsList(exclList));
293                 } else if (!pacFileUrl.isEmpty()) {
294                     profile.proxy = ProxyInfo.buildPacProxy(Uri.parse(pacFileUrl));
295                 }
296             } // else profile.proxy = null
297 
298             // Either all must be present, or none must be.
299             if (values.length >= 24) {
300                 profile.mAllowedAlgorithms = new ArrayList<>();
301                 for (String algo : Arrays.asList(values[19].split(LIST_DELIMITER))) {
302                     profile.mAllowedAlgorithms.add(URLDecoder.decode(algo, DEFAULT_ENCODING));
303                 }
304 
305                 profile.isBypassable = Boolean.parseBoolean(values[20]);
306                 profile.isMetered = Boolean.parseBoolean(values[21]);
307                 profile.maxMtu = Integer.parseInt(values[22]);
308                 profile.areAuthParamsInline = Boolean.parseBoolean(values[23]);
309             }
310 
311             // isRestrictedToTestNetworks (values[24]) assigned as part of the constructor
312 
313             profile.saveLogin = !profile.username.isEmpty() || !profile.password.isEmpty();
314             return profile;
315         } catch (Exception e) {
316             // ignore
317         }
318         return null;
319     }
320 
321     /**
322      * Encodes a VpnProfile instance to a byte array for storage.
323      *
324      * <p>See {@link #decode(String, byte[])}
325      */
encode()326     public byte[] encode() {
327         StringBuilder builder = new StringBuilder(name);
328         builder.append(VALUE_DELIMITER).append(type);
329         builder.append(VALUE_DELIMITER).append(server);
330         builder.append(VALUE_DELIMITER).append(saveLogin ? username : "");
331         builder.append(VALUE_DELIMITER).append(saveLogin ? password : "");
332         builder.append(VALUE_DELIMITER).append(dnsServers);
333         builder.append(VALUE_DELIMITER).append(searchDomains);
334         builder.append(VALUE_DELIMITER).append(routes);
335         builder.append(VALUE_DELIMITER).append(mppe);
336         builder.append(VALUE_DELIMITER).append(l2tpSecret);
337         builder.append(VALUE_DELIMITER).append(ipsecIdentifier);
338         builder.append(VALUE_DELIMITER).append(ipsecSecret);
339         builder.append(VALUE_DELIMITER).append(ipsecUserCert);
340         builder.append(VALUE_DELIMITER).append(ipsecCaCert);
341         builder.append(VALUE_DELIMITER).append(ipsecServerCert);
342         if (proxy != null) {
343             builder.append(VALUE_DELIMITER).append(proxy.getHost() != null ? proxy.getHost() : "");
344             builder.append(VALUE_DELIMITER).append(proxy.getPort());
345             builder.append(VALUE_DELIMITER)
346                     .append(
347                             ProxyUtils.exclusionListAsString(proxy.getExclusionList()) != null
348                                     ? ProxyUtils.exclusionListAsString(proxy.getExclusionList())
349                                     : "");
350             builder.append(VALUE_DELIMITER).append(proxy.getPacFileUrl().toString());
351         } else {
352             builder.append(ENCODED_NULL_PROXY_INFO);
353         }
354 
355         final List<String> encodedAlgoNames = new ArrayList<>();
356 
357         try {
358             for (String algo : mAllowedAlgorithms) {
359                 encodedAlgoNames.add(URLEncoder.encode(algo, DEFAULT_ENCODING));
360             }
361         } catch (UnsupportedEncodingException e) {
362             // Unexpected error
363             throw new IllegalStateException("Failed to encode algorithms.", e);
364         }
365 
366         builder.append(VALUE_DELIMITER).append(String.join(LIST_DELIMITER, encodedAlgoNames));
367 
368         builder.append(VALUE_DELIMITER).append(isBypassable);
369         builder.append(VALUE_DELIMITER).append(isMetered);
370         builder.append(VALUE_DELIMITER).append(maxMtu);
371         builder.append(VALUE_DELIMITER).append(areAuthParamsInline);
372         builder.append(VALUE_DELIMITER).append(isRestrictedToTestNetworks);
373 
374         return builder.toString().getBytes(StandardCharsets.UTF_8);
375     }
376 
377     /** Checks if this profile specifies a LegacyVpn type. */
isLegacyType(int type)378     public static boolean isLegacyType(int type) {
379         switch (type) {
380             case VpnProfile.TYPE_PPTP:
381             case VpnProfile.TYPE_L2TP_IPSEC_PSK:
382             case VpnProfile.TYPE_L2TP_IPSEC_RSA:
383             case VpnProfile.TYPE_IPSEC_XAUTH_PSK:
384             case VpnProfile.TYPE_IPSEC_XAUTH_RSA:
385             case VpnProfile.TYPE_IPSEC_HYBRID_RSA:
386                 return true;
387             default:
388                 return false;
389         }
390     }
391 
isValidLockdownLegacyVpnProfile()392     private boolean isValidLockdownLegacyVpnProfile() {
393         return isLegacyType(type) && isServerAddressNumeric() && hasDns()
394                 && areDnsAddressesNumeric();
395     }
396 
isValidLockdownPlatformVpnProfile()397     private boolean isValidLockdownPlatformVpnProfile() {
398         return Ikev2VpnProfile.isValidVpnProfile(this);
399     }
400 
401     /**
402      * Tests if profile is valid for lockdown.
403      *
404      * <p>For LegacyVpn profiles, this requires an IPv4 address for both the server and DNS.
405      *
406      * <p>For PlatformVpn profiles, this requires a server, an identifier and the relevant fields to
407      * be non-null.
408      */
isValidLockdownProfile()409     public boolean isValidLockdownProfile() {
410         return isTypeValidForLockdown()
411                 && (isValidLockdownLegacyVpnProfile() || isValidLockdownPlatformVpnProfile());
412     }
413 
414     /** Returns {@code true} if the VPN type is valid for lockdown. */
isTypeValidForLockdown()415     public boolean isTypeValidForLockdown() {
416         // b/7064069: lockdown firewall blocks ports used for PPTP
417         return type != TYPE_PPTP;
418     }
419 
420     /** Returns {@code true} if the server address is numeric, e.g. 8.8.8.8 */
isServerAddressNumeric()421     public boolean isServerAddressNumeric() {
422         try {
423             InetAddress.parseNumericAddress(server);
424         } catch (IllegalArgumentException e) {
425             return false;
426         }
427         return true;
428     }
429 
430     /** Returns {@code true} if one or more DNS servers are specified. */
hasDns()431     public boolean hasDns() {
432         return !TextUtils.isEmpty(dnsServers);
433     }
434 
435     /** Returns {@code true} if all DNS servers have numeric addresses, e.g. 8.8.8.8 */
areDnsAddressesNumeric()436     public boolean areDnsAddressesNumeric() {
437         try {
438             for (String dnsServer : dnsServers.split(" +")) {
439                 InetAddress.parseNumericAddress(dnsServer);
440             }
441         } catch (IllegalArgumentException e) {
442             return false;
443         }
444         return true;
445     }
446 
447     /** Generates a hashcode over the VpnProfile. */
448     @Override
hashCode()449     public int hashCode() {
450         return Objects.hash(
451             key, type, server, username, password, dnsServers, searchDomains, routes, mppe,
452             l2tpSecret, ipsecIdentifier, ipsecSecret, ipsecUserCert, ipsecCaCert, ipsecServerCert,
453             proxy, mAllowedAlgorithms, isBypassable, isMetered, maxMtu, areAuthParamsInline,
454             isRestrictedToTestNetworks);
455     }
456 
457     /** Checks VPN profiles for interior equality. */
458     @Override
equals(Object obj)459     public boolean equals(Object obj) {
460         if (!(obj instanceof VpnProfile)) {
461             return false;
462         }
463 
464         final VpnProfile other = (VpnProfile) obj;
465         return Objects.equals(key, other.key)
466                 && Objects.equals(name, other.name)
467                 && type == other.type
468                 && Objects.equals(server, other.server)
469                 && Objects.equals(username, other.username)
470                 && Objects.equals(password, other.password)
471                 && Objects.equals(dnsServers, other.dnsServers)
472                 && Objects.equals(searchDomains, other.searchDomains)
473                 && Objects.equals(routes, other.routes)
474                 && mppe == other.mppe
475                 && Objects.equals(l2tpSecret, other.l2tpSecret)
476                 && Objects.equals(ipsecIdentifier, other.ipsecIdentifier)
477                 && Objects.equals(ipsecSecret, other.ipsecSecret)
478                 && Objects.equals(ipsecUserCert, other.ipsecUserCert)
479                 && Objects.equals(ipsecCaCert, other.ipsecCaCert)
480                 && Objects.equals(ipsecServerCert, other.ipsecServerCert)
481                 && Objects.equals(proxy, other.proxy)
482                 && Objects.equals(mAllowedAlgorithms, other.mAllowedAlgorithms)
483                 && isBypassable == other.isBypassable
484                 && isMetered == other.isMetered
485                 && maxMtu == other.maxMtu
486                 && areAuthParamsInline == other.areAuthParamsInline
487                 && isRestrictedToTestNetworks == other.isRestrictedToTestNetworks;
488     }
489 
490     @NonNull
491     public static final Creator<VpnProfile> CREATOR = new Creator<VpnProfile>() {
492         @Override
493         public VpnProfile createFromParcel(Parcel in) {
494             return new VpnProfile(in);
495         }
496 
497         @Override
498         public VpnProfile[] newArray(int size) {
499             return new VpnProfile[size];
500         }
501     };
502 
503     @Override
describeContents()504     public int describeContents() {
505         return 0;
506     }
507 }
508