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/e3/S.java

@@ -0,0 +1,69 @@
+package e3;
+
+import java.nio.charset.Charset;
+import java.util.regex.Pattern;
+import kotlin.jvm.internal.Intrinsics;
+import kotlin.text.Charsets;
+import r3.InterfaceC0578j;
+
+/* loaded from: classes3.dex */
+public final class S {
+    public static Q a(A a2, long j4, InterfaceC0578j interfaceC0578j) {
+        Intrinsics.checkNotNullParameter(interfaceC0578j, "<this>");
+        return new Q(a2, j4, interfaceC0578j);
+    }
+
+    /* JADX WARN: Type inference failed for: r3v1, types: [r3.j, java.lang.Object, r3.h] */
+    public static Q b(String string, A a2) {
+        Intrinsics.checkNotNullParameter(string, "<this>");
+        Charset charset = Charsets.UTF_8;
+        if (a2 != null) {
+            Pattern pattern = A.f6197d;
+            Charset a4 = a2.a(null);
+            if (a4 == null) {
+                String str = a2 + "; charset=utf-8";
+                Intrinsics.checkNotNullParameter(str, "<this>");
+                try {
+                    a2 = z.a(str);
+                } catch (IllegalArgumentException unused) {
+                    a2 = null;
+                }
+            } else {
+                charset = a4;
+            }
+        }
+        ?? obj = new Object();
+        Intrinsics.checkNotNullParameter(string, "string");
+        Intrinsics.checkNotNullParameter(charset, "charset");
+        int length = string.length();
+        Intrinsics.checkNotNullParameter(string, "string");
+        Intrinsics.checkNotNullParameter(charset, "charset");
+        if (length < 0) {
+            throw new IllegalArgumentException(C.w.k("endIndex < beginIndex: ", length, 0, " < ").toString());
+        }
+        if (length > string.length()) {
+            StringBuilder t2 = C.w.t(length, "endIndex > string.length: ", " > ");
+            t2.append(string.length());
+            throw new IllegalArgumentException(t2.toString().toString());
+        }
+        if (Intrinsics.areEqual(charset, Charsets.UTF_8)) {
+            obj.p0(string, 0, length);
+        } else {
+            String substring = string.substring(0, length);
+            Intrinsics.checkNotNullExpressionValue(substring, "this as java.lang.String…ing(startIndex, endIndex)");
+            byte[] bytes = substring.getBytes(charset);
+            Intrinsics.checkNotNullExpressionValue(bytes, "this as java.lang.String).getBytes(charset)");
+            obj.i0(bytes, 0, bytes.length);
+        }
+        return a(a2, obj.f8284b, obj);
+    }
+
+    /* JADX WARN: Type inference failed for: r0v1, types: [r3.j, java.lang.Object, r3.h] */
+    public static Q c(byte[] source, A a2) {
+        Intrinsics.checkNotNullParameter(source, "<this>");
+        ?? obj = new Object();
+        Intrinsics.checkNotNullParameter(source, "source");
+        obj.i0(source, 0, source.length);
+        return a(a2, source.length, obj);
+    }
+}