From f2c2597379280e0aea56932647eded1c5f7cc72c Mon Sep 17 00:00:00 2001
From: AsamK <asamk@gmx.de>
Date: Sun, 3 Jul 2016 15:57:17 +0200
Subject: [PATCH] Implement trustLevel for IdentityKeys

---
 .../asamk/signal/JsonIdentityKeyStore.java    | 96 +++++++++++++++----
 1 file changed, 77 insertions(+), 19 deletions(-)

diff --git a/src/main/java/org/asamk/signal/JsonIdentityKeyStore.java b/src/main/java/org/asamk/signal/JsonIdentityKeyStore.java
index c1ef428b..332d8712 100644
--- a/src/main/java/org/asamk/signal/JsonIdentityKeyStore.java
+++ b/src/main/java/org/asamk/signal/JsonIdentityKeyStore.java
@@ -10,12 +10,14 @@ import org.whispersystems.libsignal.InvalidKeyException;
 import org.whispersystems.libsignal.state.IdentityKeyStore;
 
 import java.io.IOException;
+import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 
 class JsonIdentityKeyStore implements IdentityKeyStore {
 
-    private final Map<String, IdentityKey> trustedKeys = new HashMap<>();
+    private final Map<String, List<Identity>> trustedKeys = new HashMap<>();
 
     private final IdentityKeyPair identityKeyPair;
     private final int localRegistrationId;
@@ -26,10 +28,6 @@ class JsonIdentityKeyStore implements IdentityKeyStore {
         this.localRegistrationId = localRegistrationId;
     }
 
-    public void addTrustedKeys(Map<String, IdentityKey> keyMap) {
-        trustedKeys.putAll(keyMap);
-    }
-
     @Override
     public IdentityKeyPair getIdentityKeyPair() {
         return identityKeyPair;
@@ -42,13 +40,41 @@ class JsonIdentityKeyStore implements IdentityKeyStore {
 
     @Override
     public void saveIdentity(String name, IdentityKey identityKey) {
-        trustedKeys.put(name, identityKey);
+        saveIdentity(name, identityKey, TrustLevel.TRUSTED_UNVERIFIED);
+    }
+
+    public void saveIdentity(String name, IdentityKey identityKey, TrustLevel trustLevel) {
+        List<Identity> identities = trustedKeys.get(name);
+        if (identities == null) {
+            identities = new ArrayList<>();
+            trustedKeys.put(name, identities);
+        } else {
+            for (Identity id : identities) {
+                if (!id.identityKey.equals(identityKey))
+                    continue;
+
+                id.trustLevel = trustLevel;
+                return;
+            }
+        }
+        identities.add(new Identity(identityKey, trustLevel));
     }
 
     @Override
     public boolean isTrustedIdentity(String name, IdentityKey identityKey) {
-        IdentityKey trusted = trustedKeys.get(name);
-        return (trusted == null || trusted.equals(identityKey));
+        List<Identity> identities = trustedKeys.get(name);
+        if (identities == null) {
+            // Trust on first use
+            return true;
+        }
+
+        for (Identity id : identities) {
+            if (id.identityKey.equals(identityKey)) {
+                return id.isTrusted();
+            }
+        }
+
+        return false;
     }
 
     public static class JsonIdentityKeyStoreDeserializer extends JsonDeserializer<JsonIdentityKeyStore> {
@@ -62,24 +88,23 @@ class JsonIdentityKeyStore implements IdentityKeyStore {
                 IdentityKeyPair identityKeyPair = new IdentityKeyPair(Base64.decode(node.get("identityKey").asText()));
 
 
-                Map<String, IdentityKey> trustedKeyMap = new HashMap<>();
+                JsonIdentityKeyStore keyStore = new JsonIdentityKeyStore(identityKeyPair, localRegistrationId);
+
                 JsonNode trustedKeysNode = node.get("trustedKeys");
                 if (trustedKeysNode.isArray()) {
                     for (JsonNode trustedKey : trustedKeysNode) {
                         String trustedKeyName = trustedKey.get("name").asText();
                         try {
-                            trustedKeyMap.put(trustedKeyName, new IdentityKey(Base64.decode(trustedKey.get("identityKey").asText()), 0));
+                            IdentityKey id = new IdentityKey(Base64.decode(trustedKey.get("identityKey").asText()), 0);
+                            TrustLevel trustLevel = trustedKey.has("trustLevel") ? TrustLevel.fromInt(trustedKey.get("trustLevel").asInt()) : TrustLevel.TRUSTED_UNVERIFIED;
+                            keyStore.saveIdentity(trustedKeyName, id, trustLevel);
                         } catch (InvalidKeyException | IOException e) {
                             System.out.println(String.format("Error while decoding key for: %s", trustedKeyName));
                         }
                     }
                 }
 
-                JsonIdentityKeyStore keyStore = new JsonIdentityKeyStore(identityKeyPair, localRegistrationId);
-                keyStore.addTrustedKeys(trustedKeyMap);
-
                 return keyStore;
-
             } catch (InvalidKeyException e) {
                 throw new IOException(e);
             }
@@ -94,14 +119,47 @@ class JsonIdentityKeyStore implements IdentityKeyStore {
             json.writeNumberField("registrationId", jsonIdentityKeyStore.getLocalRegistrationId());
             json.writeStringField("identityKey", Base64.encodeBytes(jsonIdentityKeyStore.getIdentityKeyPair().serialize()));
             json.writeArrayFieldStart("trustedKeys");
-            for (Map.Entry<String, IdentityKey> trustedKey : jsonIdentityKeyStore.trustedKeys.entrySet()) {
-                json.writeStartObject();
-                json.writeStringField("name", trustedKey.getKey());
-                json.writeStringField("identityKey", Base64.encodeBytes(trustedKey.getValue().serialize()));
-                json.writeEndObject();
+            for (Map.Entry<String, List<Identity>> trustedKey : jsonIdentityKeyStore.trustedKeys.entrySet()) {
+                for (Identity id : trustedKey.getValue()) {
+                    json.writeStartObject();
+                    json.writeStringField("name", trustedKey.getKey());
+                    json.writeStringField("identityKey", Base64.encodeBytes(id.identityKey.serialize()));
+                    json.writeNumberField("trustLevel", id.trustLevel.ordinal());
+                    json.writeEndObject();
+                }
             }
             json.writeEndArray();
             json.writeEndObject();
         }
     }
+
+    private enum TrustLevel {
+        UNTRUSTED,
+        TRUSTED_UNVERIFIED,
+        TRUSTED_VERIFIED;
+
+        private static TrustLevel[] cachedValues = null;
+
+        public static TrustLevel fromInt(int i) {
+            if (TrustLevel.cachedValues == null) {
+                TrustLevel.cachedValues = TrustLevel.values();
+            }
+            return TrustLevel.cachedValues[i];
+        }
+    }
+
+    private class Identity {
+        IdentityKey identityKey;
+        TrustLevel trustLevel;
+
+        public Identity(IdentityKey identityKey, TrustLevel trustLevel) {
+            this.identityKey = identityKey;
+            this.trustLevel = trustLevel;
+        }
+
+        public boolean isTrusted() {
+            return trustLevel == TrustLevel.TRUSTED_UNVERIFIED ||
+                    trustLevel == TrustLevel.TRUSTED_VERIFIED;
+        }
+    }
 }
-- 
2.50.1