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

   1 package org.asamk.signal.manager.groups;
   2
   3 import com.google.protobuf.ByteString;
   4
   5 import org.signal.storageservice.protos.groups.GroupInviteLink;
   6 import org.signal.storageservice.protos.groups.local.DecryptedGroup;
   7 import org.signal.zkgroup.InvalidInputException;
   8 import org.signal.zkgroup.groups.GroupMasterKey;
   9 import org.whispersystems.util.Base64UrlSafe;
  10
  11 import java.io.IOException;
  12 import java.net.URI;
  13 import java.net.URISyntaxException;
  14
  15 public final class GroupInviteLinkUrl {
  16
  17     private static final String GROUP_URL_HOST = "signal.group";
  18     private static final String GROUP_URL_PREFIX = "https://" + GROUP_URL_HOST + "/#";
  19
  20     private final GroupMasterKey groupMasterKey;
  21     private final GroupLinkPassword password;
  22     private final String url;
  23
  24     public static GroupInviteLinkUrl forGroup(GroupMasterKey groupMasterKey, DecryptedGroup group) {
  25         return new GroupInviteLinkUrl(groupMasterKey,
  26                 GroupLinkPassword.fromBytes(group.getInviteLinkPassword().toByteArray()));
  27     }
  28
  29     public static boolean isGroupLink(String urlString) {
  30         return getGroupUrl(urlString) != null;
  31     }
  32
  33     /**
  34      * @return null iff not a group url.
  35      * @throws InvalidGroupLinkException If group url, but cannot be parsed.
  36      */
  37     public static GroupInviteLinkUrl fromUri(String urlString) throws InvalidGroupLinkException, UnknownGroupLinkVersionException {
  38         URI uri = getGroupUrl(urlString);
  39
  40         if (uri == null) {
  41             return null;
  42         }
  43
  44         try {
  45             if (!"/".equals(uri.getPath()) && uri.getPath().length() > 0) {
  46                 throw new InvalidGroupLinkException("No path was expected in uri");
  47             }
  48
  49             String encoding = uri.getFragment();
  50
  51             if (encoding == null || encoding.length() == 0) {
  52                 throw new InvalidGroupLinkException("No reference was in the uri");
  53             }
  54
  55             byte[] bytes = Base64UrlSafe.decodePaddingAgnostic(encoding);
  56             GroupInviteLink groupInviteLink = GroupInviteLink.parseFrom(bytes);
  57
  58             switch (groupInviteLink.getContentsCase()) {
  59                 case V1CONTENTS: {
  60                     GroupInviteLink.GroupInviteLinkContentsV1 groupInviteLinkContentsV1 = groupInviteLink.getV1Contents();
  61                     GroupMasterKey groupMasterKey = new GroupMasterKey(groupInviteLinkContentsV1.getGroupMasterKey()
  62                             .toByteArray());
  63                     GroupLinkPassword password = GroupLinkPassword.fromBytes(groupInviteLinkContentsV1.getInviteLinkPassword()
  64                             .toByteArray());
  65
  66                     return new GroupInviteLinkUrl(groupMasterKey, password);
  67                 }
  68                 default:
  69                     throw new UnknownGroupLinkVersionException("Url contains no known group link content");
  70             }
  71         } catch (InvalidInputException | IOException e) {
  72             throw new InvalidGroupLinkException(e);
  73         }
  74     }
  75
  76     /**
  77      * @return {@link URI} if the host name matches.
  78      */
  79     private static URI getGroupUrl(String urlString) {
  80         try {
  81             URI url = new URI(urlString);
  82
  83             if (!"https".equalsIgnoreCase(url.getScheme()) && !"sgnl".equalsIgnoreCase(url.getScheme())) {
  84                 return null;
  85             }
  86
  87             return GROUP_URL_HOST.equalsIgnoreCase(url.getHost()) ? url : null;
  88         } catch (URISyntaxException e) {
  89             return null;
  90         }
  91     }
  92
  93     private GroupInviteLinkUrl(GroupMasterKey groupMasterKey, GroupLinkPassword password) {
  94         this.groupMasterKey = groupMasterKey;
  95         this.password = password;
  96         this.url = createUrl(groupMasterKey, password);
  97     }
  98
  99     protected static String createUrl(GroupMasterKey groupMasterKey, GroupLinkPassword password) {
 100         GroupInviteLink groupInviteLink = GroupInviteLink.newBuilder()
 101                 .setV1Contents(GroupInviteLink.GroupInviteLinkContentsV1.newBuilder()
 102                         .setGroupMasterKey(ByteString.copyFrom(groupMasterKey.serialize()))
 103                         .setInviteLinkPassword(ByteString.copyFrom(password.serialize())))
 104                 .build();
 105
 106         String encoding = Base64UrlSafe.encodeBytesWithoutPadding(groupInviteLink.toByteArray());
 107
 108         return GROUP_URL_PREFIX + encoding;
 109     }
 110
 111     public String getUrl() {
 112         return url;
 113     }
 114
 115     public GroupMasterKey getGroupMasterKey() {
 116         return groupMasterKey;
 117     }
 118
 119     public GroupLinkPassword getPassword() {
 120         return password;
 121     }
 122
 123     public final static class InvalidGroupLinkException extends Exception {
 124
 125         public InvalidGroupLinkException(String message) {
 126             super(message);
 127         }
 128
 129         public InvalidGroupLinkException(Throwable cause) {
 130             super(cause);
 131         }
 132     }
 133
 134     public final static class UnknownGroupLinkVersionException extends Exception {
 135
 136         public UnknownGroupLinkVersionException(String message) {
 137             super(message);
 138         }
 139     }
 140 }