mirror of
https://git.k-space.ee/arti/vt1200.git
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96 lines
5.0 KiB
Plaintext
96 lines
5.0 KiB
Plaintext
Visual injection on the running VT1200 OS -- key numbers
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=========================================================
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ROM md5 b46a3e442ccb86134d2356bd70d22fd2 (unchanged). No driver edits.
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OS path: VT1200_SKIP_LEVEL1=1 (documented divergence), private -nvram_directory,
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rdebug over TCP 771 with the computed challenge (dwt/solve.py chain).
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1. `jump` is a call and returns; the OS stays alive
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---------------------------------------------------
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dwt/visual/build/ret_test.bin = 30 bytes, linked at bit 01840000h.
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Step1 log: dwt/evidence/visual/step1_ret_test.log
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jump 0x01840000: returned 0x00000000
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after-peek 0x01850000 -> de c0 07 b0 (0xC0DE, 0xB007)
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post-jump opcode 7 -> Done
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second connection at frame 3526: opcode 7 -> Done; markers still de c0 07 b0
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Frame at 3500 (step1_alive_3500.png) is the live Terminal Manager.
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So the loader is a real call: stack/return are intact, and the TCP session is
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usable before and after.
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2. Static VRAM draw lands, but the OS repaints it
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--------------------------------------------------
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drawal.bin: three word-aligned black 32x32 boxes at (48,48), (256,400),
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(928,752). Client log: dwt/evidence/visual/static_draw_client.log
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after-peek 0x0400C030 (64) -> 00 00 00 00 ff ff ... (the writes are in VRAM)
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jump returned; TCP Done; markers D2A0/B0C0.
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Frames 3420 (before) and 3430 (after) are byte-identical
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(static_before_3420.png / static_after_3430.png; md5 e98b9b4a38 both), and the
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box regions do not change in any of 3420..3600. The OS repaints before the
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next scanout.
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Control (CPU frozen after the same draw): control_spin_box_3480.png shows the
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black box, and the hello-world 256x64 block appears (control_hello_3480.png),
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so the coordinates/renderer mapping are right.
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3. Resident display-interrupt hook
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----------------------------------
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DI vector: RLONG(0xFFFFFEA0) = 00000DB0h. RAM stub there is 6 bytes:
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80 c0 d0 46 71 3f = JA 3F7146D0h (stock OS display handler)
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install rewrites the 32-bit target only:
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80 c0 90 01 84 01 = JA 01840190h (our entry)
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(both read from dwt/evidence/visual/live/runpc/vt1200-ram-3440.bin; the dump
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itself is not committed -- see di_one_shot_state.log for the same stub read
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through the running system.)
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(a) draw before the stock handler: handler runs (counter 0x0A,0x62,...), but
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no box ever appears -- the handler repaints after the draw.
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(b) return-PC trampoline (draw after the handler's `reti`): visible blink.
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Payload `dwt/visual/build/blinkev.bin` (252 bytes; the post-handler
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trampoline with scratch at 01840800h). Two runs:
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run A (blink_resident_client.log), frames 15:
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frame 3450 box region 56.2% lit (black box ON)
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frame 3480 box region 100.0% (box OFF, white body)
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frame 3500 box region 56.2% (box ON again)
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TCP answered at 3450 and at 3500 (post-jump opcode 7 -> Done).
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run B (blink_repeat_client.log), frames live3, 5-frame dumps:
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3440/3450 OFF, 3455..3520 ON (10-frame pairs):
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blink2_off_3450.png, blink2_on_3460.png, blink2_on_3500.png.
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The install returned and its post-jump opcode 7 -> Done, but a new
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connection at 3450 got the challenge then timed out, and by 3470 the
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terminal's IP stack was gone ("No route to host"). So the blink is
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reproducible, TCP survival is flaky.
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LIMIT: only the first trampoline entry draws. The stock handler's full
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path (0x3F579880) stops returning through the patched saved PC; the
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counter sticks at 1 (di_one_shot_state.log). So this is a real but
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short-lived blink, not a durable one. Breakpoint log: hook_breakpoints.log
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(ENTRY 1, RET 1, stock handler 34+).
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(c) with the settle/IE work, the one-shot post-handler draw persists: frames
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24/25 show the black box at (448..511, 400..463) for 600+ frames, and the
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OS answers TCP at 3500/3600/3700/3800/4000
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(settled_hook_client.log; settled_hook_mame.log). It does not toggle.
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(d) INT2 hook (stub 0F30h, handler 3F714530h) was tried; at idle the handler
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never takes the trampoline (counter 0), so it is not a blink source here.
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4. Window
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---------
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Port 6000 is OPEN on 192.168.99.2 (xcheck.log); 6001 is closed. An ordinary
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X client is rejected:
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xdpyinfo -display 192.168.99.2:0 -> "Client is not authorized to access server"
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So a normal X client cannot open a window without the server's auth cookie.
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Injection of a window was NOT attempted: it needs the X server's window
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structures, resource IDs and callbacks; that is a project, not an experiment.
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Evidence files
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--------------
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step1_ret_test.log, step1_alive_3500.png
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static_draw_client.log, static_before_3420.png, static_after_3430.png
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control_spin_client.log, control_spin_box_3480.png, control_hello_3480.png
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blink_resident_client.log, blink_on_3450(_crop).png, blink_off_3480(_crop).png,
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blink_on_3500.png, blink_mame.log
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blink_repeat_client.log, blink_repeat_mame.log, blink2_off_3450.png,
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blink2_on_3460.png, blink2_on_3500.png, step3_blink_client.log
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settled_hook_client.log, settled_hook_mame.log, posthandler_persist_3600.png
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di_one_shot_state.log, hook_breakpoints.log
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xcheck.log, xcheck_mame.log
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