Petition for AMD to open-source the PSP (backdoor) in their chips
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Re: Petition for AMD to open-source the PSP (backdoor) in their chips
#2They should also document their GPU firmware, so there would be an option to write an open alternative.
Re: Petition for AMD to open-source the PSP (backdoor) in their chips
#3I don't get it. This would not increase trust since we can not check if the source actually corresponds to the binary in the processor. It would need to be repeatably build-able with the result matching the signature of the default blob.
They could release a signed NO-OP firmware that is so small it would be easy to verify as benign using a disassembler. Potential of more secret code is always there, but being this malicious would be highly damaging to the company.
Re: Petition for AMD to open-source the PSP (backdoor) in their chips
#4Releasing the PSP source code would AFAIK not change a thing. While it might be an interesting read, the PSP (i.e. AMD) would still remain in control of the platform. The PSP does NOT rely on code obfuscation. It is a much deeper architectural problem with he PSP, than the fact that it holds a binary blob.
The designer of the Intel Management Engine (the mother of the PSP) Xiaoyu Ruan wrote in his book "Platform Embedded Security Technology Revealed" in chapter 4:
"By design, the firmware binary should not contain secrets, and hence it is not encrypted or obfuscated in any form. Note that lossless compression may be applied to the code. The firmware binary, in its compression form, is stored on SPI flash in cleartext. At runtime, the code segment is not encrypted when it is paged out to DRAM. Admittedly, advanced hackers have successfully reverse-engineered and disassembled the engine’s firmware binary. However, knowledge of source code is not deemed a harmful threat, because no secrets or keys are ever hardcoded in the code, and the architecture and robustness of the engine does not rely on security through obscurity."
Further in chapter 11:
"Hardware root of trust: Binary code and the data of firmware components are stored in the flash memory in the clear. Encryption is not used because the security architecture does not rely on security through obscurity. The concept of hardware root of trust contains two folds: first, the root of trust for integrity is a hardware ROM (read-only memory). Unlike the firmware in the flash memory, the binary of ROM by design is not available externally. Although, even if the code of ROM is leaked, the security of the engine should not be impacted; second, the EPID (enhanced privacy identification; see Chapter 5 for details) private key and other chipset keys are burned into the engine’s security fuse block in Intel’s factory. These keys comprise the root of trust for confidentiality and privacy for the engine."
https://link.springer.com/book/10.1007%2F978-1-4302-6572-6
So IMHO AMD should be asked to produce a chip without the PSP. Or offer the possibility to disable it. As long as there is a PSP on the system it cannot be fully controlled by the user, even if it's source code should be known. It is a small autonomous computer with it's own CPU, RAM, ROM, clock etc that has fully privileged access to the systems components and can load and run code anytime (so it can run other code than the firmware source code).
Nevertheless I do see that there is a good side to these kinds of petitions and requests. AMD feels that there is interest in the subject.
Re: Petition for AMD to open-source the PSP (backdoor) in their chips
#5They should also document their GPU firmware, so there would be an option to write an open alternative.
Have they released an open source implementation of their Vulkan driver, or did I dream that? And didn't Nvidia promise something similar? Has anything come out of those promises?
Re: Petition for AMD to open-source the PSP (backdoor) in their chips
#6I don't get it. This would not increase trust since we can not check if the source actually corresponds to the binary in the processor. It would need to be repeatably build-able with the result matching the signature of the default blob. They could release a signed NO-OP firmware that is so small it would be easy to verify as benign using a disassembler. Potential of more secret code is always there, but being this m…
Is there any way you can trust the CPU to tell you what code in the PSP is running though?
Re: Petition for AMD to open-source the PSP (backdoor) in their chips
#7They should also document their GPU firmware, so there would be an option to write an open alternative.
Have they released an open source implementation of their Vulkan driver, or did I dream that? And didn't Nvidia promise something similar? Has anything come out of those promises?
No, they never released it. They said several times, that they are working on opening it though. They already replaced their previous shader compiler with llvm toolchain for example, but there is more work than that.
Meanwhile, radv is advancing pretty well. AMD never clarified what their strategy is in regards to radv. I.e. whether they plan to compliment it with their Vulkan driver, or they intend to make a second open one.
Nvidia never promised anything like that.
Re: Petition for AMD to open-source the PSP (backdoor) in their chips
#8I don't get it. This would not increase trust since we can not check if the source actually corresponds to the binary in the processor. It would need to be repeatably build-able with the result matching the signature of the default blob. They could release a signed NO-OP firmware that is so small it would be easy to verify as benign using a disassembler. Potential of more secret code is always there, but being this m…
>It would need to be repeatably build-able with the result matching the signature of the default blob.
Huh? You can most certainly verify if an unsigned blob matches a signed blob.
Re: Petition for AMD to open-source the PSP (backdoor) in their chips
#9A company like AMD isn't going to be concerned with customer privacy and security unless it affects their bottom line. If the market was hostile to closed drivers and processor firmware no one would bother selling these types of systems because it wouldn't make sense financially.
The consumers have spoken: they're OK with trusting computer manufactures, software vendors, telecommunications carriers and governments. To me and perhaps other people interested in security that's unfortunate but to device manufactures, they're simply giving the market want it wants.
Re: Petition for AMD to open-source the PSP (backdoor) in their chips
#10A company like AMD isn't going to be concerned with customer privacy and security unless it affects their bottom line. If the market was hostile to closed drivers and processor firmware no one would bother selling these types of systems because it wouldn't make sense financially. The consumers have spoken: they're OK with trusting computer manufactures, software vendors, telecommunications carriers and governments. T…
The consumers have spoken: they're OK with trusting computer manufactures, software vendors, telecommunications carriers and governments.
Please be careful with statements like this! With the wrong speaker, they can justify all kinds of evils.
I'd be willing to wager some high 90s percent of people buying electronics don't even consider privacy at the hardware level because they don't even have the proper knowledge to have the mental state to ask those questions in the first place.
That does not mean that consumers are "OK" with it, any more than consumers care about dihydrogen monoxide in their food until they're told about it.