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

   1 package org.asamk.signal.manager.api;
   2
   3 import com.google.protobuf.ByteString;
   4
   5 import org.asamk.signal.manager.groups.GroupLinkPassword;
   6 import org.signal.libsignal.zkgroup.InvalidInputException;
   7 import org.signal.libsignal.zkgroup.groups.GroupMasterKey;
   8 import org.signal.storageservice.protos.groups.GroupInviteLink;
   9 import org.signal.storageservice.protos.groups.local.DecryptedGroup;
  10 import org.whispersystems.util.Base64UrlSafe;
  11
  12 import java.io.IOException;
  13 import java.net.URI;
  14 import java.net.URISyntaxException;
  15
  16 public final class GroupInviteLinkUrl {
  17
  18     private static final String GROUP_URL_HOST = "signal.group";
  19     private static final String GROUP_URL_PREFIX = "https://" + GROUP_URL_HOST + "/#";
  20
  21     private final GroupMasterKey groupMasterKey;
  22     private final GroupLinkPassword password;
  23     private final String url;
  24
  25     public static GroupInviteLinkUrl forGroup(GroupMasterKey groupMasterKey, DecryptedGroup group) {
  26         return new GroupInviteLinkUrl(groupMasterKey,
  27                 GroupLinkPassword.fromBytes(group.getInviteLinkPassword().toByteArray()));
  28     }
  29
  30     /**
  31      * @return null iff not a group url.
  32      * @throws InvalidGroupLinkException If group url, but cannot be parsed.
  33      */
  34     public static GroupInviteLinkUrl fromUri(String urlString) throws InvalidGroupLinkException, UnknownGroupLinkVersionException {
  35         var uri = getGroupUrl(urlString);
  36
  37         if (uri == null) {
  38             return null;
  39         }
  40
  41         try {
  42             if (!"/".equals(uri.getPath()) && uri.getPath().length() > 0) {
  43                 throw new InvalidGroupLinkException("No path was expected in uri");
  44             }
  45
  46             var encoding = uri.getFragment();
  47
  48             if (encoding == null || encoding.length() == 0) {
  49                 throw new InvalidGroupLinkException("No reference was in the uri");
  50             }
  51
  52             var bytes = Base64UrlSafe.decodePaddingAgnostic(encoding);
  53             var groupInviteLink = GroupInviteLink.parseFrom(bytes);
  54
  55             switch (groupInviteLink.getContentsCase()) {
  56                 case V1CONTENTS -> {
  57                     var groupInviteLinkContentsV1 = groupInviteLink.getV1Contents();
  58                     var groupMasterKey = new GroupMasterKey(groupInviteLinkContentsV1.getGroupMasterKey()
  59                             .toByteArray());
  60                     var password = GroupLinkPassword.fromBytes(groupInviteLinkContentsV1.getInviteLinkPassword()
  61                             .toByteArray());
  62
  63                     return new GroupInviteLinkUrl(groupMasterKey, password);
  64                 }
  65                 default -> throw new UnknownGroupLinkVersionException("Url contains no known group link content");
  66             }
  67         } catch (InvalidInputException | IOException e) {
  68             throw new InvalidGroupLinkException(e);
  69         }
  70     }
  71
  72     /**
  73      * @return {@link URI} if the host name matches.
  74      */
  75     private static URI getGroupUrl(String urlString) {
  76         try {
  77             var url = new URI(urlString);
  78
  79             if (!"https".equalsIgnoreCase(url.getScheme()) && !"sgnl".equalsIgnoreCase(url.getScheme())) {
  80                 return null;
  81             }
  82
  83             return GROUP_URL_HOST.equalsIgnoreCase(url.getHost()) ? url : null;
  84         } catch (URISyntaxException e) {
  85             return null;
  86         }
  87     }
  88
  89     private GroupInviteLinkUrl(GroupMasterKey groupMasterKey, GroupLinkPassword password) {
  90         this.groupMasterKey = groupMasterKey;
  91         this.password = password;
  92         this.url = createUrl(groupMasterKey, password);
  93     }
  94
  95     private static String createUrl(GroupMasterKey groupMasterKey, GroupLinkPassword password) {
  96         var groupInviteLink = GroupInviteLink.newBuilder()
  97                 .setV1Contents(GroupInviteLink.GroupInviteLinkContentsV1.newBuilder()
  98                         .setGroupMasterKey(ByteString.copyFrom(groupMasterKey.serialize()))
  99                         .setInviteLinkPassword(ByteString.copyFrom(password.serialize())))
 100                 .build();
 101
 102         var encoding = Base64UrlSafe.encodeBytesWithoutPadding(groupInviteLink.toByteArray());
 103
 104         return GROUP_URL_PREFIX + encoding;
 105     }
 106
 107     public String getUrl() {
 108         return url;
 109     }
 110
 111     public GroupMasterKey getGroupMasterKey() {
 112         return groupMasterKey;
 113     }
 114
 115     public GroupLinkPassword getPassword() {
 116         return password;
 117     }
 118
 119     public final static class InvalidGroupLinkException extends Exception {
 120
 121         public InvalidGroupLinkException(String message) {
 122             super(message);
 123         }
 124
 125         public InvalidGroupLinkException(Throwable cause) {
 126             super(cause);
 127         }
 128     }
 129
 130     public final static class UnknownGroupLinkVersionException extends Exception {
 131
 132         public UnknownGroupLinkVersionException(String message) {
 133             super(message);
 134         }
 135     }
 136 }