Encode prekey as full JSON rather than protobuf blobs.

1) Split prekey messages out into full JSON.

2) Add support for retrieving prekeys.

library/src/org/whispersystems/textsecure/push/PreKeyEntity.java

@@ -0,0 +1,109 @@
+package org.whispersystems.textsecure.push;
+
+import com.google.thoughtcrimegson.GsonBuilder;
+import com.google.thoughtcrimegson.JsonDeserializationContext;
+import com.google.thoughtcrimegson.JsonDeserializer;
+import com.google.thoughtcrimegson.JsonElement;
+import com.google.thoughtcrimegson.JsonParseException;
+import com.google.thoughtcrimegson.JsonPrimitive;
+import com.google.thoughtcrimegson.JsonSerializationContext;
+import com.google.thoughtcrimegson.JsonSerializer;
+import org.whispersystems.textsecure.crypto.IdentityKey;
+import org.whispersystems.textsecure.crypto.InvalidKeyException;
+import org.whispersystems.textsecure.crypto.PreKeyPublic;
+import org.whispersystems.textsecure.util.Base64;
+
+import java.io.IOException;
+import java.lang.reflect.Type;
+
+public class PreKeyEntity {
+
+  private long         keyId;
+  private PreKeyPublic publicKey;
+  private IdentityKey  identityKey;
+
+  public PreKeyEntity(long keyId, PreKeyPublic publicKey, IdentityKey identityKey) {
+    this.keyId       = keyId;
+    this.publicKey   = publicKey;
+    this.identityKey = identityKey;
+  }
+
+  public long getKeyId() {
+    return keyId;
+  }
+
+  public PreKeyPublic getPublicKey() {
+    return publicKey;
+  }
+
+  public IdentityKey getIdentityKey() {
+    return identityKey;
+  }
+
+  public static String toJson(PreKeyEntity entity) {
+    return getBuilder().create().toJson(entity);
+  }
+
+  public static PreKeyEntity fromJson(String encoded) {
+    return getBuilder().create().fromJson(encoded, PreKeyEntity.class);
+  }
+
+  public static GsonBuilder getBuilder() {
+    GsonBuilder builder = new GsonBuilder();
+    builder.registerTypeAdapter(PreKeyPublic.class, new PreKeyPublicJsonAdapter());
+    builder.registerTypeAdapter(IdentityKey.class, new IdentityKeyJsonAdapter());
+
+    return builder;
+  }
+
+  private static class PreKeyPublicJsonAdapter
+      implements JsonSerializer<PreKeyPublic>, JsonDeserializer<PreKeyPublic>
+  {
+    @Override
+    public JsonElement serialize(PreKeyPublic preKeyPublic, Type type,
+                                 JsonSerializationContext jsonSerializationContext)
+    {
+      return new JsonPrimitive(Base64.encodeBytesWithoutPadding(preKeyPublic.serialize()));
+    }
+
+    @Override
+    public PreKeyPublic deserialize(JsonElement jsonElement, Type type,
+                                    JsonDeserializationContext jsonDeserializationContext)
+        throws JsonParseException
+    {
+      try {
+        return new PreKeyPublic(Base64.decodeWithoutPadding(jsonElement.getAsJsonPrimitive().getAsString()), 0);
+      } catch (InvalidKeyException e) {
+        throw new JsonParseException(e);
+      } catch (IOException e) {
+        throw new JsonParseException(e);
+      }
+    }
+  }
+
+  private static class IdentityKeyJsonAdapter
+      implements JsonSerializer<IdentityKey>, JsonDeserializer<IdentityKey>
+  {
+    @Override
+    public JsonElement serialize(IdentityKey identityKey, Type type,
+                                 JsonSerializationContext jsonSerializationContext)
+    {
+      return new JsonPrimitive(Base64.encodeBytesWithoutPadding(identityKey.serialize()));
+    }
+
+    @Override
+    public IdentityKey deserialize(JsonElement jsonElement, Type type,
+                                   JsonDeserializationContext jsonDeserializationContext)
+        throws JsonParseException
+    {
+      try {
+        return new IdentityKey(Base64.decodeWithoutPadding(jsonElement.getAsJsonPrimitive().getAsString()), 0);
+      } catch (InvalidKeyException e) {
+        throw new JsonParseException(e);
+      } catch (IOException e) {
+        throw new JsonParseException(e);
+      }
+    }
+  }
+
+}

library/src/org/whispersystems/textsecure/push/PreKeyList.java

@@ -4,13 +4,17 @@ import java.util.List;
 
 public class PreKeyList {
 
-  private List<String> keys;
+  private List<PreKeyEntity> keys;
 
-  public PreKeyList(List<String> keys) {
+  public PreKeyList(List<PreKeyEntity> keys) {
     this.keys = keys;
   }
 
-  public List<String> getKeys() {
+  public List<PreKeyEntity> getKeys() {
     return keys;
   }
+
+  public static String toJson(PreKeyList entity) {
+    return PreKeyEntity.getBuilder().create().toJson(entity);
+  }
 }

library/src/org/whispersystems/textsecure/push/PushServiceSocket.java

@@ -9,8 +9,9 @@ import com.google.thoughtcrimegson.Gson;
 import org.whispersystems.textsecure.R;
 import org.whispersystems.textsecure.Release;
 import org.whispersystems.textsecure.crypto.IdentityKey;
+import org.whispersystems.textsecure.crypto.PreKeyPair;
+import org.whispersystems.textsecure.crypto.PreKeyPublic;
 import org.whispersystems.textsecure.directory.DirectoryDescriptor;
-import org.whispersystems.textsecure.encoded.PreKeyProtos.PreKeyEntity;
 import org.whispersystems.textsecure.storage.PreKeyRecord;
 import org.whispersystems.textsecure.util.Base64;
 import org.whispersystems.textsecure.util.Util;
@@ -41,7 +42,7 @@ public class PushServiceSocket {
   private static final String CREATE_ACCOUNT_VOICE_PATH = "/v1/accounts/voice/%s";
   private static final String VERIFY_ACCOUNT_PATH       = "/v1/accounts/code/%s";
   private static final String REGISTER_GCM_PATH         = "/v1/accounts/gcm/";
-  private static final String PREKEY_PATH               = "/v1/keys/";
+  private static final String PREKEY_PATH               = "/v1/keys/%s";
 
   private static final String DIRECTORY_PATH            = "/v1/directory/";
   private static final String MESSAGE_PATH              = "/v1/messages/";
@@ -111,22 +112,23 @@ public class PushServiceSocket {
   public void registerPreKeys(IdentityKey identityKey, List<PreKeyRecord> records)
       throws IOException
   {
-    List<String> encoded = new LinkedList<String>();
+    List<PreKeyEntity> entities = new LinkedList<PreKeyEntity>();
 
     for (PreKeyRecord record : records) {
-        PreKeyEntity entity  = PreKeyEntity.newBuilder().setId(record.getId())
-                                           .setPublicKey(ByteString.copyFrom(record.getEncodedPublicKey()))
-                                           .setIdentityKey(ByteString.copyFrom(identityKey.serialize()))
-                                           .build();
-
-        String encodedEntity = Base64.encodeBytesWithoutPadding(entity.toByteArray());
-
-        encoded.add(encodedEntity);
+      PreKeyEntity entity = new PreKeyEntity(record.getId(),
+                                             record.getKeyPair().getPublicKey(),
+                                             identityKey);
+      entities.add(entity);
     }
 
-     makeRequest(PREKEY_PATH, "PUT", new Gson().toJson(new PreKeyList(encoded)));
+     makeRequest(String.format(PREKEY_PATH, ""), "PUT", PreKeyList.toJson(new PreKeyList(entities)));
   }
 
+  public PreKeyEntity getPreKey(String number) throws IOException {
+    String responseText = makeRequest(String.format(PREKEY_PATH, number), "GET", null);
+    Log.w("PushServiceSocket", "Got prekey: " + responseText);
+    return PreKeyEntity.fromJson(responseText);
+  }
 
   private List<PushAttachmentPointer> sendAttachments(List<PushAttachmentData> attachments)
       throws IOException