From 269390e7eea36619843edb96ddf8d491741e7f6d Mon Sep 17 00:00:00 2001 From: Dante Catalfamo Date: Tue, 12 Oct 2021 22:02:01 -0400 Subject: xprinter-wifi: init article --- content/posts/WIP-xprinter-wifi/index.org | 256 +++++++++++++++++++++ .../posts/WIP-xprinter-wifi/xprinter_advanced.png | Bin 0 -> 24148 bytes .../posts/WIP-xprinter-wifi/xprinter_set_net.png | Bin 0 -> 11419 bytes .../WIP-xprinter-wifi/xprinter_setup_tool.png | Bin 0 -> 46156 bytes .../posts/WIP-xprinter-wifi/xprinter_wireshark.png | Bin 0 -> 160032 bytes 5 files changed, 256 insertions(+) create mode 100644 content/posts/WIP-xprinter-wifi/index.org create mode 100644 content/posts/WIP-xprinter-wifi/xprinter_advanced.png create mode 100644 content/posts/WIP-xprinter-wifi/xprinter_set_net.png create mode 100644 content/posts/WIP-xprinter-wifi/xprinter_setup_tool.png create mode 100644 content/posts/WIP-xprinter-wifi/xprinter_wireshark.png diff --git a/content/posts/WIP-xprinter-wifi/index.org b/content/posts/WIP-xprinter-wifi/index.org new file mode 100644 index 0000000..a566239 --- /dev/null +++ b/content/posts/WIP-xprinter-wifi/index.org @@ -0,0 +1,256 @@ +#+TITLE: Setting up an Xprinter thermal receipt printer WiFi from Linux +#+DATE: 2021-10-12T15:57:12-04:00 +#+DRAFT: true +#+DESCRIPTION: +#+TAGS[]: +#+KEYWORDS[]: +#+SLUG: +#+SUMMARY: + +I recently purchased a thermal receipt printer off of [[https://web.archive.org/web/20211012195845/https://www.aliexpress.com/item/32842111016.html?spm=a2g0s.9042311.0.0.207d4c4d6xNWgO][AliExpress]] for a +project. It features both WiFi and USB connectivity which I thought +was really cool for the price. + +To my dismay, I realized after purchasing that the drivers and +configuration application only run on Windows. + +This wasn't a huge deal, as thermal printers generally use the +somewhat kinda standardized command set called [[https://github.com/escpos/escpos][ESC/POS]]. Unfortunately +while many of the formatting commands are shared between printers, the +commands to setup the WiFi connection don't seem to be documented +anywhere, and I suspect are device-specific. + +Since booting into Windows every time I want to manage the printer's +network settings isn't ideal, I decided to reverse engineer the +WiFi configuration protocol. + +Initially I tried to run the configuration tool in wine, but it +couldn't communicate with the printer over USB, which wasn't too +surprising. + +I booted my spare laptop into windows and launched the config tool +there. + +I then setup the WiFi through =Advanced -> Set Net= + +#+ATTR_HTML: :title Xprinter config tool running in wine +#+ATTR_HTML: :alt Xprinter config tool running in wine +[[file:xprinter_setup_tool.png]] + + +#+ATTR_HTML: :title Xprinter advanced settings +#+ATTR_HTML: :alt Xprinter advanced settings +[[file:xprinter_advanced.png]] + +#+ATTR_HTML: :title Xprinter net settings +#+ATTR_HTML: :alt Xprinter net settings +[[file:xprinter_set_net.png]] + +At this point I noticed that the application supported configuring the +printer over the network, meaning I might be able to change the +settings under wine again, as network sockets should work normally. + +After rebooting into Linux and testing my assumption, it turned out to +be true, I was able to run the configuration tool without issue as +long as it was connected through the network. + +While I could have stopped there I decided to go one step further and +reverse the command sequence that configures the WiFi settings so I +could re-configure the printer's WiFi over USB if it ever got messed +up. + +To do that, I sniffed the traffic going from the Xprinter application +and the printer's socket using Wireshark. + +[[file:xprinter_wireshark.png]] + +In the examples below I've encoded the decimal numbers to hex to make +it easier to understand the contents of the packets. + +Based on the traffic, I was able to come up with the following. + +* Setting IP address + + The following sets + - IP =192.168.0.7= + + The IP hex: + #+begin_src ruby + [192, 168, 0, 7].map { _1.to_s(16).rjust(2, '0') } + #+end_src + + #+RESULTS: + | c0 | a8 | 00 | 07 | + + Packate contents from wireshark: + + =0000 1f 1b 1f 22 c0 a8 00 07= + + | Description | Characters | + |----------------+---------------| + | Unit separator | =1f= | + | Escape | =1b= | + | Unit separator | =1f= | + | Command code | =22= | + | IP | =c0 a8 00 07= | + +* Setting Subnet Mask + + The following sets + - Subnet mask =255.255.255.0= + + Subnet mask to hex: + #+begin_src ruby + [255, 255, 255, 0].map { _1.to_s(16).rjust(2, '0') } + #+end_src + + #+RESULTS: + | ff | ff | ff | 00 | + + Packate contents from wireshark: + + =0000 1f 1b 1f b0 ff ff ff 00= + + | Description | Character | + |----------------+---------------| + | Unit separator | =1f= | + | Escape | =1b= | + | Unit separator | =1f= | + | Command code | =b0= | + | Subnet mask | =ff ff ff 00= | + +* Setting gateway + + The following sets + - Gateway =192.168.0.1= + + Subnet mask to hex: + #+begin_src ruby + [192, 168, 0, 1].map { _1.to_s(16).rjust(2, '0') } + #+end_src + + #+RESULTS: + | c0 | a8 | 00 | 01 | + + Packate contents from wireshark: + + =0000 1f 1b 1f b1 c0 a8 00 01= + + | Description | Character | + |----------------+---------------| + | Unit separator | =1f= | + | Escape | =1b= | + | Unit separator | =1f= | + | Command code | =b1= | + | Net Mask | =c0 a8 00 01= | + +* Setting IP, netmask, and gateway + + The following sets + - IP =192.168.0.1= + - Subnet mask =255.255.255.0= + - Gateway =192.168.0.1= + + Packate contents from wireshark: + + =0000 1f 1b 1f b2 c0 a8 00 07 ff ff ff 00 c0 a8 00 01= + + | Purpose | Character | + |----------------+---------------| + | Unit separator | =1f= | + | Escape | =1b= | + | Unit separator | =1f= | + | Command code | =b2= | + | IP | =c0 a8 00 07= | + | Subnet mask | =ff ff ff 00= | + | Gateway | =c0 a8 00 01= | + +* Setting WiFi network + + The following sets + - SSID =SSID_HERE= + - Key =PASSWORD_HERE= + - Key Type =WPA2_AES_PSK= + + SSID to hex: + #+begin_src ruby + "SSID_HERE".bytes.map { _1.to_s(16) } + #+end_src + + #+RESULTS: + | 53 | 53 | 49 | 44 | 5f | 48 | 45 | 52 | 45 | + + Key to hex: + #+begin_src ruby + "PASSWORD_HERE".bytes.map { _1.to_s(16) } + #+end_src + + #+RESULTS: + | 50 | 41 | 53 | 53 | 57 | 4f | 52 | 44 | 5f | 48 | 45 | 52 | 45 | + + Packate contents from wireshark (including string representation): + #+begin_src + 0000 1f 1b 1f b3 06 53 53 49 44 5f 48 45 52 45 00 50 .....SSID_HERE.P + 0010 41 53 53 57 4f 52 44 5f 48 45 52 45 00 ASSWORD_HERE. + #+end_src + + | Purpose | Character | + |-----------------+-----------------| + | Unit separator | =1f= | + | Escape | =1b= | + | Unit separator | =1f= | + | Command code | =b3= | + | Key type | =06= | + | SSID | =SSID_HERE= | + | NUL-termination | =00= | + | Key | =PASSWORD_HERE= | + | NUL-termination | =00= | + + If the WiFi key type is anything like the menu, the other key types + are as follows + + | Key Type | Value | + |----------------------+-------| + | =NULL= | =00= | + | =WEP64= | =01= | + | =WEP128= | =02= | + | =WPA_AES_PSK= | =03= | + | =WPA_TKIP_PSK= | =04= | + | =WPA_TKIP_AES_PSK= | =05= | + | =WPA2_AES_PSK= | =06= | + | =WPA2_TKIP= | =07= | + | =WPA2_TKIP_AES_PSK= | =08= | + | =WPA_WPA2_MixedMode= | =09= | + +* Setting all network options + + The following sets + - IP =192.168.0.7= + - Subnet mask =255.255.255.0= + - Gateway =192.168.0.1= + - SSID =SSID_HERE= + - Key =PASSWORD_HERE= + - Key Type =WPA2_AES_PSK= + + Packate contents from wireshark (including string representation): + + #+begin_src + 0000 1f 1b 1f b4 c0 a8 00 07 ff ff ff 00 c0 a8 00 01 ................ + 0010 06 53 53 49 44 5f 48 45 52 45 00 50 41 53 53 57 .SSID_HERE.PASSW + 0020 4f 52 44 5f 48 45 52 45 00 ORD_HERE. + #+end_src + + | Description | Character | + |-----------------+-----------------| + | Unit Separator | =1f= | + | Escape | =1b= | + | Unit Separator | =1f= | + | Command Code | =b4= | + | IP | =c0 a8 00 07= | + | NetMask | =ff ff ff 00= | + | Gateway | =c0 a8 00 01= | + | Key Type | =06= | + | SSID | =SSID_HERE= | + | NUL-termination | =00= | + | Key | =PASSWORD_HERE= | + | NUL-termination | =00= | diff --git a/content/posts/WIP-xprinter-wifi/xprinter_advanced.png b/content/posts/WIP-xprinter-wifi/xprinter_advanced.png new file mode 100644 index 0000000..ded4185 Binary files /dev/null and b/content/posts/WIP-xprinter-wifi/xprinter_advanced.png differ diff --git a/content/posts/WIP-xprinter-wifi/xprinter_set_net.png b/content/posts/WIP-xprinter-wifi/xprinter_set_net.png new file mode 100644 index 0000000..329422a Binary files /dev/null and b/content/posts/WIP-xprinter-wifi/xprinter_set_net.png differ diff --git a/content/posts/WIP-xprinter-wifi/xprinter_setup_tool.png b/content/posts/WIP-xprinter-wifi/xprinter_setup_tool.png new file mode 100644 index 0000000..a5e5004 Binary files /dev/null and b/content/posts/WIP-xprinter-wifi/xprinter_setup_tool.png differ diff --git a/content/posts/WIP-xprinter-wifi/xprinter_wireshark.png b/content/posts/WIP-xprinter-wifi/xprinter_wireshark.png new file mode 100644 index 0000000..1b70a27 Binary files /dev/null and b/content/posts/WIP-xprinter-wifi/xprinter_wireshark.png differ -- cgit v1.2.3