prolific counterfeiting
prolific counterfeiting
2023-10-09
I'm working on a side project right now, one of several, which involves<br>telematics devices (essentially GPS trackers with i/o) from a fairly reputable<br>Chinese manufacturer. The device is endlessly configurable and so, like you see<br>with a lot of radios, it has a UART for programming. The manufacturer provided<br>a cable for this purpose, and when I plug it into my laptop running Windows, it<br>appears in the device manager as "DOES NOT SUPPORT WINDOWS 11." What a world.
This is one of those things that I bump into perhaps once a month working on<br>various odds and ends, especially radios. It's the collateral damage of the<br>serial adapter wars.
Counterfeiting is an interesting aspect of the contemporary hardware industry,<br>particularly for programmable microcontrollers sold for higher-level<br>applications. My first exposure to this strange world was probably the ELM327.<br>A company called ELM Electronics developed the ELM327, basically a PIC<br>microcontroller with software they wrote. It provides a serial interface and<br>command set for interacting with OBD-II diagnostic ports. The ELM327 was widely<br>used for serial, USB, and Bluetooth OBD-II readers, and it was a lot more<br>widely used after someone dumped the ROM from one and started selling their own<br>PICs with the same software---cheaper.
Suddenly, online marketplaces were flooded with inexpensive USB and Bluetooth<br>OBD-II readers, all described as ELM32. They were of course counterfeits. For<br>the most part they seemed functional, but the counterfeits did often have<br>issues with unreliable Bluetooth and power consumption behavior. More to the<br>point, the counterfeits were stuck, versionwise. Later ELM327 versions took<br>standard measures to avoid the ROM being read out. Counterfeits often reported<br>fake version numbers to look more in line with the genuine item, but they only<br>had the featureset of the original. Of course this made it annoyingly hard to<br>tell what capabilities an ELM327 device actually had.
The story of the PL-2303 is similar. The Prolific PL-2303 was almost certainly<br>the most popular USB-UART controller on the market. Nearly every USB serial<br>adapter for years was based on the PL-2303, most offboard programming cables<br>for embedded devices used it, and there were even devices that used a PL-2303<br>internally as a simple way to present a USB interface. The problem is that not<br>that many of these PL-2303s were actually PL-2303s.
I don't think this is quite as clearly a case of cloning as the ELM327. It<br>seems like what happened is that a lot of vendors independently implemented<br>USB-UART chips that implemented the same interface as the PL-2303, based on<br>reverse engineering. That might have made for some sort of defense were it<br>not for the fact that a lot of these "PL-2303 compatibles" were being sold as<br>outright counterfeits---with Prolific part numbers and trademarks.
Prolific responded to counterfeiting almost uniquely aggressively. To be clear,<br>there is some debate about Prolific's motivations at the beginning of the<br>serial adapter war. More skeptical commentators tend to accuse them of outright<br>profiteering through a form of planned obsolescence. I don't necessarily think<br>that Prolific was this clearly malicious, but they clearly had a certain<br>disregard for the interests of their customers. Prolific's anti-counterfeit<br>strategy evolved over a few years from guerrilla to scorched earth.
In the first wave, Prolific started modifying the device drivers they<br>distributed to perform additional tests on PL-2303 chips before they would<br>function. Sometime in the early '10s the first shells landed. "PL-2303"<br>adapters that had worked fine suddenly became unreliable, and it was a<br>crapshoot whether any given USB-serial adapter would function. As a user it was<br>hard to understand why, and so a general view proliferated that USB serial<br>adapters were extremely unreliable.
There was a bit of a weakness in Prolific's strategy, though: the "genuineness"<br>checks were only present in newer versions of the driver. Counterfeit chips<br>could be made to work just by rolling the driver back to a previous version.<br>For several years, it was routine for USB-serial adapters to come with a mini<br>CD containing a very old version of the Prolific driver, and a note explaining<br>that use of the "special" driver was mandatory.
Around 2015, Prolific got more aggressive, introducing a new tactic they would<br>return to again: the "new Windows support" scheme.
Prolific retired the PL-2303 variants they had been selling an introduced a new<br>variant. There were some minor new features, but the main selling point on the<br>new variant was "Windows 8 support"... a bit of a surprise since the original<br>models had been working fine with Windows 8. But Prolific had an interesting<br>idea of what "Windows 8 support" meant: they released a new driver version,<br>distributed by Windows Update, that whitelisted PL-2303 variants based on<br>Windows release. If the system was...