nmode's Git Repositories - signal-cli/blob - lib/src/main/java/org/asamk/signal/manager/helper/UnidentifiedAccessHelper.java

   1 package org.asamk.signal.manager.helper;
   2
   3 import org.asamk.signal.manager.api.PhoneNumberSharingMode;
   4 import org.asamk.signal.manager.api.Profile;
   5 import org.asamk.signal.manager.internal.SignalDependencies;
   6 import org.asamk.signal.manager.storage.SignalAccount;
   7 import org.asamk.signal.manager.storage.recipients.RecipientId;
   8 import org.signal.libsignal.metadata.certificate.InvalidCertificateException;
   9 import org.signal.libsignal.metadata.certificate.SenderCertificate;
  10 import org.signal.libsignal.zkgroup.profiles.ProfileKey;
  11 import org.slf4j.Logger;
  12 import org.slf4j.LoggerFactory;
  13 import org.whispersystems.signalservice.api.crypto.UnidentifiedAccess;
  14 import org.whispersystems.signalservice.api.crypto.UnidentifiedAccessPair;
  15
  16 import java.io.IOException;
  17 import java.util.List;
  18 import java.util.Optional;
  19 import java.util.concurrent.TimeUnit;
  20
  21 public class UnidentifiedAccessHelper {
  22
  23     private static final Logger logger = LoggerFactory.getLogger(UnidentifiedAccessHelper.class);
  24     private static final long CERTIFICATE_EXPIRATION_BUFFER = TimeUnit.DAYS.toMillis(1);
  25     private static final byte[] UNRESTRICTED_KEY = new byte[16];
  26
  27     private final SignalAccount account;
  28     private final SignalDependencies dependencies;
  29     private final Context context;
  30
  31     private SenderCertificate privacySenderCertificate;
  32     private SenderCertificate senderCertificate;
  33
  34     public UnidentifiedAccessHelper(final Context context) {
  35         this.account = context.getAccount();
  36         this.dependencies = context.getDependencies();
  37         this.context = context;
  38     }
  39
  40     public void rotateSenderCertificates() {
  41         privacySenderCertificate = null;
  42         senderCertificate = null;
  43     }
  44
  45     public List<Optional<UnidentifiedAccessPair>> getAccessFor(List<RecipientId> recipients) {
  46         return recipients.stream().map(this::getAccessFor).toList();
  47     }
  48
  49     public Optional<UnidentifiedAccessPair> getAccessFor(RecipientId recipient) {
  50         return getAccessFor(recipient, false);
  51     }
  52
  53     public Optional<UnidentifiedAccessPair> getAccessFor(RecipientId recipientId, boolean noRefresh) {
  54         var recipientUnidentifiedAccessKey = getTargetUnidentifiedAccessKey(recipientId, noRefresh);
  55         if (recipientUnidentifiedAccessKey == null) {
  56             logger.trace("Unidentified access not available for {}", recipientId);
  57             return Optional.empty();
  58         }
  59
  60         var selfUnidentifiedAccessKey = getSelfUnidentifiedAccessKey(noRefresh);
  61         if (selfUnidentifiedAccessKey == null) {
  62             logger.trace("Unidentified access not available for self");
  63             return Optional.empty();
  64         }
  65
  66         var senderCertificate = getSenderCertificateFor(recipientId);
  67         if (senderCertificate == null) {
  68             logger.trace("Unidentified access not available due to missing sender certificate");
  69             return Optional.empty();
  70         }
  71
  72         try {
  73             return Optional.of(new UnidentifiedAccessPair(new UnidentifiedAccess(recipientUnidentifiedAccessKey,
  74                     senderCertificate,
  75                     false), new UnidentifiedAccess(selfUnidentifiedAccessKey, senderCertificate, false)));
  76         } catch (InvalidCertificateException e) {
  77             return Optional.empty();
  78         }
  79     }
  80
  81     public Optional<UnidentifiedAccessPair> getAccessForSync() {
  82         var selfUnidentifiedAccessKey = getSelfUnidentifiedAccessKey(false);
  83         var selfUnidentifiedAccessCertificate = getSenderCertificate();
  84
  85         if (selfUnidentifiedAccessKey == null || selfUnidentifiedAccessCertificate == null) {
  86             return Optional.empty();
  87         }
  88
  89         try {
  90             return Optional.of(new UnidentifiedAccessPair(new UnidentifiedAccess(selfUnidentifiedAccessKey,
  91                     selfUnidentifiedAccessCertificate,
  92                     false),
  93                     new UnidentifiedAccess(selfUnidentifiedAccessKey, selfUnidentifiedAccessCertificate, false)));
  94         } catch (InvalidCertificateException e) {
  95             return Optional.empty();
  96         }
  97     }
  98
  99     private byte[] getSenderCertificateFor(final RecipientId recipientId) {
 100         final var sharingMode = account.getConfigurationStore().getPhoneNumberSharingMode();
 101         if (sharingMode == PhoneNumberSharingMode.EVERYBODY || (
 102                 sharingMode == PhoneNumberSharingMode.CONTACTS
 103                         && account.getContactStore().getContact(recipientId) != null
 104         )) {
 105             logger.trace("Using normal sender certificate for message to {}", recipientId);
 106             return getSenderCertificate();
 107         } else {
 108             logger.trace("Using phone number privacy sender certificate for message to {}", recipientId);
 109             return getSenderCertificateForPhoneNumberPrivacy();
 110         }
 111     }
 112
 113     private byte[] getSenderCertificateForPhoneNumberPrivacy() {
 114         if (privacySenderCertificate != null && System.currentTimeMillis() < (
 115                 privacySenderCertificate.getExpiration() - CERTIFICATE_EXPIRATION_BUFFER
 116         )) {
 117             return privacySenderCertificate.getSerialized();
 118         }
 119         try {
 120             final var certificate = dependencies.getAccountManager().getSenderCertificateForPhoneNumberPrivacy();
 121             privacySenderCertificate = new SenderCertificate(certificate);
 122             return certificate;
 123         } catch (IOException | InvalidCertificateException e) {
 124             logger.warn("Failed to get sender certificate, ignoring: {}", e.getMessage());
 125             return null;
 126         }
 127     }
 128
 129     private byte[] getSenderCertificate() {
 130         if (senderCertificate != null && System.currentTimeMillis() < (
 131                 senderCertificate.getExpiration() - CERTIFICATE_EXPIRATION_BUFFER
 132         )) {
 133             return senderCertificate.getSerialized();
 134         }
 135         try {
 136             final var certificate = dependencies.getAccountManager().getSenderCertificate();
 137             this.senderCertificate = new SenderCertificate(certificate);
 138             return certificate;
 139         } catch (IOException | InvalidCertificateException e) {
 140             logger.warn("Failed to get sender certificate, ignoring: {}", e.getMessage());
 141             return null;
 142         }
 143     }
 144
 145     private byte[] getSelfUnidentifiedAccessKey(boolean noRefresh) {
 146         var selfProfile = noRefresh
 147                 ? account.getProfileStore().getProfile(account.getSelfRecipientId())
 148                 : context.getProfileHelper().getSelfProfile();
 149         if (selfProfile != null
 150                 && selfProfile.getUnidentifiedAccessMode() == Profile.UnidentifiedAccessMode.UNRESTRICTED) {
 151             return createUnrestrictedUnidentifiedAccess();
 152         }
 153         return UnidentifiedAccess.deriveAccessKeyFrom(account.getProfileKey());
 154     }
 155
 156     private byte[] getTargetUnidentifiedAccessKey(RecipientId recipientId, boolean noRefresh) {
 157         var targetProfile = noRefresh
 158                 ? account.getProfileStore().getProfile(recipientId)
 159                 : context.getProfileHelper().getRecipientProfile(recipientId);
 160         if (targetProfile == null) {
 161             return null;
 162         }
 163
 164         var theirProfileKey = account.getProfileStore().getProfileKey(recipientId);
 165         return getTargetUnidentifiedAccessKey(targetProfile, theirProfileKey);
 166     }
 167
 168     private static byte[] getTargetUnidentifiedAccessKey(
 169             final Profile targetProfile, final ProfileKey theirProfileKey
 170     ) {
 171         return switch (targetProfile.getUnidentifiedAccessMode()) {
 172             case ENABLED -> theirProfileKey == null ? null : UnidentifiedAccess.deriveAccessKeyFrom(theirProfileKey);
 173             case UNRESTRICTED -> createUnrestrictedUnidentifiedAccess();
 174             default -> null;
 175         };
 176     }
 177
 178     private static byte[] createUnrestrictedUnidentifiedAccess() {
 179         return UNRESTRICTED_KEY;
 180     }
 181 }