2022-12-21 Having a "When 10 meter is open, it's really open" day
When I started with HF in amateur radio (below 30 MHz) in August 2014 making PSK31 contacts on the 10 meter band the number of sunspots was falling, the maximum frequency for ionospheric propagation was falling and therefore the possibilities of making contacts on the 10 meter band were dropping. In 2022 we are in the rise of the number of sunspots as part of solar cycle 25. And this year there are clearly moments where I can get interesting contacts on the 10 meter band. Today I had some time to play radio in the morning and I got contacts with China, India, UK bases on Cyprus, Macedonia and Hong Kong. The contacts were in FT8 mode. It is nice to see this. Radio amateurs who have been active for years will tell you about the good times when you can make contacts on the 10 meter band during the day with minimal means. Now I am enjoying this myself and having fun all over the world.
2022-12-14 Making a CTF challenge with an NFC tag
On 9 December this year was the annual SURFcert Capture The Flag (CTF) event. The end result is that team "I'm not a robot" from Radbout University Nijmegen won with the most points. When I participate in a CTF, I like to keep notes and write about my experiences and what I learned solving the challenges. Being on the 'other' side creating the challenges is as much fun, but while creating the challenges you have to be really silent about it. For me personally it is extra challenging because one of the regular SURFcert CTF players works with me in the same team. But sometimes designing a challenge and making it happen gives the same great feeling as actually solving it! This was the case with the challenge that ended up as Scan the radio on the SURFcert CTF. The name of the challenge was somewhat confusing by design: there was a challenge which was designed to make people use a 1990s style ghettoblaster radio, there was a challenge mentioning 'broadcast' which was actually about names of wifi networks and this challenge. All three were marked 'physical' with a description of the challenge. For this challenge I wanted to create an NFC tag that could be read easily. I found out information can be put in NFC tags using the NDEF standard (NFC Data Exchange Format) which has options to embed URLs, options to start certain apps or simple strings. I wanted a simple string with a flag as our flag format was SCF2022- plus 32 characters uppercase. I found out the developer of proxmark is working on NDEF support but it is all quite new. At this point I was worried I had to write my own code and use parts from a fresh library to get an NDEF message on a card. I did bring some MiFare classic cards home to test on. But searching for information I came across NDEF and Magic Mifare Cards with the very important remark:My suggestion would be to get an Android phone with nxp reader chip (there are many) and use tagwriter from NXP to format and write ndef data to the Mifare classic chip.I do have NFC TagWriter by NXP on a smartphone, I just haven't used it a lot. And indeed it was really easy to create an NDEF dataset with a string, write this to a MiFare classic and read this with an Android phone with NFC support, even without opening the NXP TagInfo application. So that was an easy challenge to make, a lot easier than I first thought. Or was it? The final test would be to read this on an Apple iphone too. And there came the snag, the Apple iphone doesn't work with MiFare classic tags somehow. But the person who helped me test it had another tag with an NDEF message on it, and that worked fine. So the conclusion was that another type of tag would work better. Luckily one of the other people of the team creating the SURFcert CTF has a big collection of NFC tags and it turned out the tag given out by Tweakers reads fine on Android and iphone. So that's how the 'scan the radio' challenge was to notice the clearly not from 1992 tweakers tag on the ghettoblaster radio, scan it with the standard NFC support in a smartphone or use NXP TagInfo and find the flag. While creating this challenge I also tried writing information to the tags which were given out / sold about 15 years ago which looked like a circle with a hex serial number. I always assumed they were just a serial number to look up in a database. But they turned out to be actual NDEF tags with the hex serial number on the outside as an URL: For the tag with 04B7CC193E2580 on the outside:
protocol 01 http://www uri field ttag.be/m/04B7CC193E2580 But ttag.be has changed owners since this was active and it's now redirecting to 609.es which is a real-estate agent in Spain. I guess everybody who scans a round tag with a serial number wonders how they end up with a real-estate agent.
2022-11-28 I participated in the CQ World-Wide DX Contest CW
Last weekend was the CQ World-Wide DX Contest CW and I participated in that contest on parts of Saturday and Sunday. I ended with 189 contacts. Daytime I worked on the 10 and 15 meter bands and when those started to dry out I switched to the 20 meter and 40 meter amateur bands. Most of the time I chased stations in search+pounce mode but I also called CQ on the 15 meter band on Sunday afternoon. I will need to practise more with calling CQ: stations came to me at higher speeds than I was used to with running PA900UTR and if I didn't decode the callsign and reacted immediately some give up fast. But my morse is improving, even at contest speeds and I got a nice number of countries in the log. Even countries I didn't have in morse before: PJ2 Curacao, PJ4 Bonaire, CX Uruguay, 3B8 Mauritius, CN Morroco, SV9 Crete. Of those Mauritius is a completely new country in amateur radio for me. I put in some extra effort to get those new countries in the log, with other stations that I know are confirmed countries I give up after a few tries and try to get another call in the log. Radio contesting is about the numbers: both number of contacts and the multipliers. In this contest the number of CQ zones and countries is the multiplier, so I optimise a bit for that number. And I suspect a lot of the other contestants do the same. The overview of my single operator multi band effort:Read the rest of I participated in the CQ World-Wide DX Contest CWBand 160 80 40 20 15 10 QSO's 0 0 28 33 108 20 Cty 0 0 18 22 31 10 Zone 0 0 5 8 11 6 Pts: 344 Mul: 111 Score: 38184This was one of those contests where I had it all planned beforehand to participate, made sure everything was working optimally and had it marked in the family calendar. Normal things like weekend shopping still needed time, but the family wasn't surprised I spent a lot of time behind the radio.
2022-11-24 Next steps digging into the hardware are more on the software side
From a perspective of security research I only touched the surface of the security research on the Corinex CXWC-HD200-WNeH and the Cab.Link CLS-D4E2WX1 by finding default credentials for telnet. To get a further insight I need to first enumerate the network attack surface completely. What services are running, what programs run those services. The ultimate step would be to build an emulation environment where I can run the programs from the routers under my control and find out about the programs and get a first few steps into reverse engineering. With qemu it is possible to emulate MIPS systems on x86 hardware, so I can build a test environment. It would need some work to get old enough versions of code and kernels to create a compatible environment. The Corinex router mentions compilation in 2012 but with Linux kernel 2.6.21 which was released 25 april 2007. The Cab.Link router mentions compilation in 2013 but uses Linux kernel 2.6.31 which was released 9 september 2009.
2022-11-22 Opening the Cab.Link CLS-D4E2WX1 and getting full access
Read the rest of Opening the Cab.Link CLS-D4E2WX1 and getting full accessAfter getting a good look at the Cab.Link CLS-D4E2WX1 from the outside it was time to void the warranty and open the box. The two screws are hiding under the little rubber feet at the front side and after removing those two screws the case opens with a bit of jiggling. This device has an external 12 volt 1 ampere power supply. Chips found on the board:
I also see an extra board (leftside of the picture, blue) where the u.fl cable to the wifi antenna starts. It has a few larger chips but those have a label over them. I guess one of them must be the CPU because I haven't seen a chip with that function yet. The makers of the Cab.Link CLS-D4E2WX1 were kind enough to include 4 pins labeled J30 (bottom left of the picture) which are a very obvious candidate for being the uart port. Again the process for find GND, TX, RX and Vcc was done and the right pins found. With the board in front and the J30 readable the pins are from left to right TX, RX, GND and 3.3 volt. I name the TX and RX pins from the view of the system, so I see data transmitted on TX and I send data to RX.
- Realtek RTL8306E - 6-port 10/100 mbps ethernet switch controller
- Winbond W9412G6KH-5 - DRAM 128MBIT memory
- Qualcomm QCA7411L-AL3C - Homeplug AV / IEEE 1901 the ethernet over cable interface I guess
2022-11-20 I participated in the LZ-DX contest
I was planning to make some morse contacts this weekend but when I had time to turn on the radio on Saturday afternoon there was a lot of contest traffic on the morse parts of the bands. This turned out to be the LZ-DX contest. This was a chance to get some CW contest practise done. This is a CW and SSB contest but I concentrate on CW contesting at the moment. I found out TLF the contest logger supports the LZ-DX contest out of the box so I could start fast. Propagation wasn't cooperating very well but I did get contacts in the log. The final result:Band Qso Cancelled Dup Point ITU-Mult LZ-Mult Score 80M 0 0 0 0 0 0 40M 38 0 0 199 7 11 20M 30 0 0 131 6 9 15M 0 0 0 0 0 0 10M 1 0 0 1 1 0 ------------------------------------------------------------------- 69 0 0 331 14 20 11254
2022-11-19 Next hardware to poke around in: Cab.Link CLS-D4E2WX1 router
The earlier Ethernet over Cable modem/router I poked at didn't come alone, from the same source I also got a Cab.Link CLS-D4E2WX1 cable modem/router. Doing a search for it finds actual listings for trying to order them wholesale: Buy Wholesale China 7400-eoc Slave Modem, Separate Tv And Ethernet From One Cable, 4 Ethernet Ports Output & 7400-eoc Slave Modem at USD 127 | Global Sources and Eoc Male Slave 4 Ethernet Port With Wifi - Buy Eoc Esclavo Product on Alibaba.com. Both listings call it an EOC slave. Given the terminology I expected EOC master devices to exist as well and I soon found out those exist and can be pricey. So I'm not going to spend money on this subject, but I may be interested in recycling an EOC master unit. The unit has one external wifi antenna, 4 ethernet ports, external power supply 12V and 9 leds. The cable connection is via 2 female F connectors with one labeled 'Cable' and one labeled 'TV'. I do notice the case has a lot of ventilation holes. On the underside is a label with the manufacturer name, model name, a default equipment management IP 10.10.1.250, a Wireless Network Name 'wifi' and the EOC and Wifi Mac addresses as numbers and barcodes, and the serial number as number and barcode. The unit has four little rubber feet (full LRF support) and two of those are hiding screws to open the unit. On switching the Cab.Link router on I indeed see a wifi network appear with the name 'wifi' which on connecting gives me an IPv4 address in the 192.168.1.x range with the default gateway 192.168.1.1.The Cab.Link router has a web interface listening on port 80. It directly asks for http authorization but using admin/admin for username and password gets me right in. Up until now I haven't found any reference to PLC or EOC in the webinterface. The Cab.Link also has a telnet server running on port 23. It greets me with an OpenWRT banner but the first few attempts at finding username/password do not let me in:$ telnet 192.168.1.1 Trying 192.168.1.1... Connected to 192.168.1.1. Escape character is '^]'. WARNING: telnet is a security risk OpenWrt login: admin Password: Login incorrect OpenWrt login: root Password: Login incorrect OpenWrt login:I like the 'telnet is a security risk' warning!
2022-11-18 SSL scans showing up in the log
A comment on irc made me have a look at the logs for my haproxy system to get an idea whether any weird vulnerability scan came by. No special vulnerability scan showed up, but my attention was drawn to a number of lines like:Nov 18 08:05:01 wozniak haproxy: 2001:470:1:332::28:37618 [18/Nov/2022:08:05:01.900] https-in/1: SSL handshake failure Nov 18 08:05:44 wozniak haproxy: 2001:470:1:332::28:27286 [18/Nov/2022:08:05:44.328] https-in/1: SSL handshake failure Nov 18 08:06:22 wozniak haproxy: 2001:470:1:332::2e:3137 [18/Nov/2022:08:06:21.962] https-in/1: SSL handshake failure Nov 18 08:06:22 wozniak haproxy: 2001:470:1:332::2d:33085 [18/Nov/2022:08:06:22.278] https-in/1: SSL handshake failure Nov 18 08:06:22 wozniak haproxy: 2001:470:1:332::2d:17531 [18/Nov/2022:08:06:22.593] https-in/1: SSL handshake failure Nov 18 08:06:22 wozniak haproxy: 2001:470:1:332::30:58869 [18/Nov/2022:08:06:22.915] https-in/1: SSL handshake failure Nov 18 08:06:23 wozniak haproxy: 2001:470:1:332::2e:46537 [18/Nov/2022:08:06:23.228] https-in/1: SSL handshake failure Nov 18 08:06:23 wozniak haproxy: 2001:470:1:332::29:20027 [18/Nov/2022:08:06:23.544] https-in/1: SSL handshake failure Nov 18 08:06:24 wozniak haproxy: 2001:470:1:332::31:13423 [18/Nov/2022:08:06:23.872] https-in/1: SSL handshake failure Nov 18 08:06:24 wozniak haproxy: 2001:470:1:332::28:56683 [18/Nov/2022:08:06:24.197] https-in/1: SSL handshake failure Nov 18 08:06:24 wozniak haproxy: 2001:470:1:332::31:5055 [18/Nov/2022:08:06:24.524] https-in/1: SSL handshake failure Nov 18 08:06:24 wozniak haproxy: 2001:470:1:332::2e:20907 [18/Nov/2022:08:06:24.841] https-in/1: SSL handshake failureIf there is one of two of these lines from one address, it is a sign of a client which can't finish the SSL negotiation. With my site that probably means and old client which doesn't understand LetsEncrypt certificates without an extra certification path. But this is quote a number of SSL errors from the same IPv6 range in a short time. I wondered what was behind this and did a bit of testing, until I found it's simple to cause this by doing an SSL test. For example with the famous Qualys SSL test or with an ssl scan tool. This is logical: ssltest uses a lot of different negotiations to test what actually works.
2022-11-18 Current thoughts on hardware hacking
I closed the case of a vulnerability in the Corinex CXWC-HD200-WNeH with a confirmation from the vendor that this is a device completely out of support. Which confirms the public information I found when I started looking into this device. This was all related to the course in hardware hacking I took and applying the new knowledge. So now I can look back on this experience and think about my future here. Hardware hacking has serious links to my current job as technical security specialist. In my work I regularly have to look at vulnerabilities and assess the chance and impact of misuse of the vulnerability. With hardware hacking I find vulnerabilities by researching hardware. This helps me understand the chance and impact factor of other vulnerabilities. There is also a link to my education: part of that was MTS electronics. I learned how to solder, before SMD components were a thing and I think I got some explanation about switching mode power supplies at the end. As I got into computers I didn't do much with this education but the last years in amateur radio have made me get out the soldering iron again. There is a clear link to my hobby of amateur radio. My interest in amateur radio is linked to wanting to know how things actually work. Hardware hacking is also done with RF signals so I may get into more RF related hardware hacking. My current thought is that I want to continue in this subject. It's given me joy: getting into a device in new and unexpected ways gives joy! I have learned new things. I noticed I need to feed the brain regularly with new information and actually learning something new is much better brainfood than browsing social media. At the same time social media is the way to learn more about this subject and interact with other people interested in this subject. I ended up on /r/hardwarehacking on reddit and already learned from others and shared some of my own insights! There is the thing about RFID/NFC security. I have looked into this in the past, mostly by getting the tools to peek into the MiFare classic cards. I am considering going further with this area of hardware hacking. Prices of hacking tools for this area like the proxmark3 or the flipper zero are above the 'nice to try a few things' level. On the other hand I think I could have loads of fun there, and the overlap with amateur radio is very clear. At the end of this bit of writing: thanks to people who share their hardware hacking experiences on-line! Thanks to Jilles Groenendijk, Router Archeology: Sitecom WL-330 - Habbie's journal, @Flashback Team on youtube, Make Me Hack on youtube, and Boschko Security for sharing their stories and knowledge.
2022-11-09 Working on my morse skillsItems with tag english before 2022-11-09
Since passing the morse exam I have continued working on my morse skills. As one of the reasons for wanting to learn morse was to be able to participate in morse radio contesting I still want to increase my speed and accuracy in copying callsigns. Exercising with tools like lcwo.net and Morse Runner helps improve these skills. But I'm also working on these skills 'on-air'. At the radio club I've done morse activations of special call PA900UTR a few times and that went ok. I don't get all the calls right the first time but it is a good experience and it's working out.