Feature Request: Multi-Page Flow Support for Evil Portal

[Michel666-def]

Summary:
Enable Evil Portal to handle multi-page HTML flows, where one page redirects to another after form submission (e.g., page1 → page2 → page3), while maintaining the ability to parse and log data from each page via the same Flask backend.

Use case examples:

• WiFi Registration Flow: Collect name → confirm via SMS → show thank-you screen.

• Local game: Step-by-step interaction where each screen collects part of user input.

• Legal forms: Collect personal details across multiple pages in a natural UX.

Requirements:

1. Allow multiple HTML files per portal in /www/portals/XYZ/.

2. Data from each form page is forwarded to Flask endpoint /api/username (or /api/log).

3. Every POST is logged separately (invoer.txt, codes.txt, etc.).

4. Easy switching between portal sets (e.g., /portals/gamename1/, /portals/hotel_wifi/).

5. Works with current evil_portal.py and supports Telegram/webhook forwarding.

6. (Optional) Enable .fab commands to activate a full portal folder with all pages.

Why this matters:
This makes Evil Portal suitable for realistic, multi-step flows without hardcoding or replacing HTMLs manually, which helps in development, testing, education, awareness, and security auditing.

[Michel666-def]

I’d like to extend Issue #12 with a real-world use case: EvilPortal pages that use local SMS verification.

Here’s the concept:

⚠️ Use case:

1. User connects to EvilPortal over WiFi (Blackhat AP)
2. Fills in name + phone number
3. Gets redirected to a second form asking for a 4-digit SMS code
4. Blackhat sends this code locally via LTE dongle (ZTE or Huawei)
5. When code is entered, access is granted / redirected

This works completely offline — no internet needed. Only a dongle and Blackhat OS.

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✅ What’s needed in Blackhat OS:

Kernel config:

CONFIG_USB_SERIAL
CONFIG_USB_SERIAL_OPTION
CONFIG_USB_NET_CDC_ETHER
CONFIG_USB_NET_RNDIS_HOST
CONFIG_USB_NET_QMI_WWAN
CONFIG_USB_NET_CDC_MBIM
CONFIG_USB_MODEM_SUPPORT

Buildroot packages:

• usb_modeswitch
• curl
• udhcpc
• comgt
• (optional) python3 + pyserial

Optional:

Allow /mnt/sd/init.sh to auto-configure LTE interface and launch SMS sender.

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📎 Real-world: I'm building this portal now

I can share full HTML, Python, and CGI scripts — already tested on Ubuntu.

Would love to see this integrated into the main image, or at least supported via a blackhat_lte_defconfig.

Let me know how I can help test it!