Primer paso de la investigacion. Se aportan el .apk, las carpetas con el apk extraido y el apk descompilado. El archivo API_DOCUMENTATION.md es un archivo donde se anotaran los descubrimientos del funcionamiento de la API, y los .py son scripts para probar la funcionalidad de la API con los métodos que vayamos encontrando. Finalmente, los archivos .js son scripts de Frida para extraer informacion de la APP durante la ejecucion.

apk_decompiled/sources/com/google/firebase/encoders/json/JsonDataEncoderBuilder.java

@@ -0,0 +1,149 @@
+package com.google.firebase.encoders.json;
+
+import com.google.firebase.encoders.DataEncoder;
+import com.google.firebase.encoders.EncodingException;
+import com.google.firebase.encoders.ObjectEncoder;
+import com.google.firebase.encoders.ObjectEncoderContext;
+import com.google.firebase.encoders.ValueEncoder;
+import com.google.firebase.encoders.ValueEncoderContext;
+import com.google.firebase.encoders.config.Configurator;
+import com.google.firebase.encoders.config.EncoderConfig;
+import java.io.IOException;
+import java.io.StringWriter;
+import java.io.Writer;
+import java.text.DateFormat;
+import java.text.SimpleDateFormat;
+import java.util.Date;
+import java.util.HashMap;
+import java.util.Locale;
+import java.util.Map;
+import java.util.TimeZone;
+
+/* loaded from: classes3.dex */
+public final class JsonDataEncoderBuilder implements EncoderConfig<JsonDataEncoderBuilder> {
+    private static final ValueEncoder<Boolean> BOOLEAN_ENCODER;
+    private static final ValueEncoder<String> STRING_ENCODER;
+    private static final ObjectEncoder<Object> DEFAULT_FALLBACK_ENCODER = new Object();
+    private static final TimestampEncoder TIMESTAMP_ENCODER = new TimestampEncoder();
+    private final Map<Class<?>, ObjectEncoder<?>> objectEncoders = new HashMap();
+    private final Map<Class<?>, ValueEncoder<?>> valueEncoders = new HashMap();
+    private ObjectEncoder<Object> fallbackEncoder = DEFAULT_FALLBACK_ENCODER;
+    private boolean ignoreNullValues = false;
+
+    /* loaded from: classes3.dex */
+    public static final class TimestampEncoder implements ValueEncoder<Date> {
+        private static final DateFormat rfc339;
+
+        static {
+            SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'", Locale.US);
+            rfc339 = simpleDateFormat;
+            simpleDateFormat.setTimeZone(TimeZone.getTimeZone("UTC"));
+        }
+
+        private TimestampEncoder() {
+        }
+
+        @Override // com.google.firebase.encoders.Encoder
+        public void encode(Date date, ValueEncoderContext valueEncoderContext) throws IOException {
+            valueEncoderContext.add(rfc339.format(date));
+        }
+    }
+
+    /* JADX WARN: Type inference failed for: r0v0, types: [java.lang.Object, com.google.firebase.encoders.ObjectEncoder<java.lang.Object>] */
+    static {
+        final int i = 0;
+        STRING_ENCODER = new ValueEncoder() { // from class: com.google.firebase.encoders.json.b
+            @Override // com.google.firebase.encoders.Encoder
+            public final void encode(Object obj, ValueEncoderContext valueEncoderContext) {
+                switch (i) {
+                    case 0:
+                        valueEncoderContext.add((String) obj);
+                        return;
+                    default:
+                        JsonDataEncoderBuilder.lambda$static$2((Boolean) obj, valueEncoderContext);
+                        return;
+                }
+            }
+        };
+        final int i4 = 1;
+        BOOLEAN_ENCODER = new ValueEncoder() { // from class: com.google.firebase.encoders.json.b
+            @Override // com.google.firebase.encoders.Encoder
+            public final void encode(Object obj, ValueEncoderContext valueEncoderContext) {
+                switch (i4) {
+                    case 0:
+                        valueEncoderContext.add((String) obj);
+                        return;
+                    default:
+                        JsonDataEncoderBuilder.lambda$static$2((Boolean) obj, valueEncoderContext);
+                        return;
+                }
+            }
+        };
+    }
+
+    public JsonDataEncoderBuilder() {
+        registerEncoder(String.class, (ValueEncoder) STRING_ENCODER);
+        registerEncoder(Boolean.class, (ValueEncoder) BOOLEAN_ENCODER);
+        registerEncoder(Date.class, (ValueEncoder) TIMESTAMP_ENCODER);
+    }
+
+    /* JADX INFO: Access modifiers changed from: private */
+    public static /* synthetic */ void lambda$static$0(Object obj, ObjectEncoderContext objectEncoderContext) throws IOException {
+        throw new EncodingException("Couldn't find encoder for type " + obj.getClass().getCanonicalName());
+    }
+
+    /* JADX INFO: Access modifiers changed from: private */
+    public static /* synthetic */ void lambda$static$2(Boolean bool, ValueEncoderContext valueEncoderContext) throws IOException {
+        valueEncoderContext.add(bool.booleanValue());
+    }
+
+    public DataEncoder build() {
+        return new DataEncoder() { // from class: com.google.firebase.encoders.json.JsonDataEncoderBuilder.1
+            @Override // com.google.firebase.encoders.DataEncoder
+            public void encode(Object obj, Writer writer) throws IOException {
+                JsonValueObjectEncoderContext jsonValueObjectEncoderContext = new JsonValueObjectEncoderContext(writer, JsonDataEncoderBuilder.this.objectEncoders, JsonDataEncoderBuilder.this.valueEncoders, JsonDataEncoderBuilder.this.fallbackEncoder, JsonDataEncoderBuilder.this.ignoreNullValues);
+                jsonValueObjectEncoderContext.add(obj, false);
+                jsonValueObjectEncoderContext.close();
+            }
+
+            @Override // com.google.firebase.encoders.DataEncoder
+            public String encode(Object obj) {
+                StringWriter stringWriter = new StringWriter();
+                try {
+                    encode(obj, stringWriter);
+                } catch (IOException unused) {
+                }
+                return stringWriter.toString();
+            }
+        };
+    }
+
+    public JsonDataEncoderBuilder configureWith(Configurator configurator) {
+        configurator.configure(this);
+        return this;
+    }
+
+    public JsonDataEncoderBuilder ignoreNullValues(boolean z3) {
+        this.ignoreNullValues = z3;
+        return this;
+    }
+
+    public JsonDataEncoderBuilder registerFallbackEncoder(ObjectEncoder<Object> objectEncoder) {
+        this.fallbackEncoder = objectEncoder;
+        return this;
+    }
+
+    @Override // com.google.firebase.encoders.config.EncoderConfig
+    public <T> JsonDataEncoderBuilder registerEncoder(Class<T> cls, ObjectEncoder<? super T> objectEncoder) {
+        this.objectEncoders.put(cls, objectEncoder);
+        this.valueEncoders.remove(cls);
+        return this;
+    }
+
+    @Override // com.google.firebase.encoders.config.EncoderConfig
+    public <T> JsonDataEncoderBuilder registerEncoder(Class<T> cls, ValueEncoder<? super T> valueEncoder) {
+        this.valueEncoders.put(cls, valueEncoder);
+        this.objectEncoders.remove(cls);
+        return this;
+    }
+}