6 ms·

Does any of this do away with things like AMD Platform Security Processor? https://en.wikipedia.org/wiki/AMD_Platform_Security_Processor https://en.wikipedia.or

Does any of this do away with things like AMD Platform Security Processor? https://en.wikipedia.org/wiki/AMD_Platform_Security_Processor https://en.wikipedia.org/wiki/AMD_Platform_Security_Processo...

deleted 4y ago
[deleted]
oneplane 4y ago
Probably not, both because the PSP can be part of the SIL bringup which you statically link anyway, and because plenty of business customers want a Secure Enclave and the legal world is having a hard time getting paperwork to suggest it's both secure and open at the same time.
kmeisthax 4y ago
No, and you can't remove the PSP without rearchitecturing the processor. However, they could release a PSP firmware that just loads the x86 cores with your chosen BIOS and then halts. Businesses that want their systems to have management backdoors[0] can use the PSP firmware that implements that functionality, while users that care about Free boot chains can use the minimized firmware. [0] Is it a backdoor if the owner put it there deliberately to be able to detect regular OS-level viruses?
- gray_charger 4y ago
  PSP is a trusted execution environment not a remote management platform. There is no reason anyone should want to remove this from a privacy perspective. In fact, privacy and security software may be hindered without something like PSP or SGX.
  - the8472 4y ago
    Perhaps if you could replace the trust root with your own. But as they are now it's the manufacturer that's in control.
    - mjg59 4y ago
      If you don't trust the manufacturer of your CPU, how do you trust any of the software running on that CPU?
      - ploxiln 4y ago
        Well, you don't have that much choice of CPU manufacturers, if you want a 65W+ performance class CPU, so you do the best you can. But anyway, there are many manufacturers that were happy to sell widgets without internet-connected software, and compete on the quality and price of those widgets in a fairly honest way. But when it became possible to embed software that can send data to the internet somehow, well various departments just could not resist demanding their engineers do so. Support costs can be massively reduced if you can just see what the stupid user did and remote in with the backdoor key and fix their misconfigured router/vpn/appliance (true story). And your marketing and product-planning teams are just severely hobbled by not having all the telemetry they can dream of, there's just millions wasted on team salaries and marketing spend if they can't get that user data sent to the SAAS marketing/crm tool they want. But when a car didn't have internet-connected computers in it, they just had to do without. We trust CPU manufacturers to act like reasonable companies. They make some good stuff, that's how they make money. They're not fly-by-night ventures. They can't risk the huge investments in their brand and their business. And they're not malicious spies trying to screw with you via very tricky microcode. But if they can conveniently put some value-add in the hidden support cpu because the marketing or support team really needed it ...
        mjg59 4y ago
        The PSP is in the CPU, not the motherboard chipset, and doesn't have any access to the network. You can't get commands to it bypassing the main CPU.
      - the8472 4y ago
        It's about the continued leverage they have by holding the key after you bought the CPU. They could be forced by secret court to sign backdoored firmware. And of course you can't load your own firmware, only whatever they release and sign. If they're generous they'll release a stripped-down version, sure, but that's still their choice, not yours.
  - justinclift 4y ago
    "Trusted by whom" is the problem. If the end user was in control of the PSP, that'd be great. :) However that's not the case. :(
    - gray_charger 4y ago
      If the end user was "in control" of the PSP that'd defeat the purpose. These features are supposed to remain a secure enclave even if the machine is compromised.
      - justinclift 4y ago
        Yeah, that's clearly not even fit for purpose by design. At least from the perspective of end users. :) Thinking about it a bit more, it also seems to be at odds with how security in the world works. Is there any case of having equipment be in the hands of end users for unlimited time (and without supervision), where the security doesn't get cracked? Once a single exploitable bug in the implementation is discovered, the whole thing becomes useless. Perhaps worse than useless, once malware starts to embed itself in the PSP.
  - kmeisthax 4y ago
    So, if I remember correctly AMD PSP started out as a response to Intel ME, whose main selling point at the time was that businesses could remote into a compromised system and wipe malware without the malware being able to fight back. PSP also enables a few other things like encrypted virtualization - being able to lock AWS's staff out of the contents of my VMs' memory. That sort of feature isn't really useful to individual consumers. SGX is an interesting case since Intel actually axed the feature a year ago. The only thing it did was enable more DRM for 4K Blu-Rays, and Hollywood's response to that feature going away has been to just refuse to let you play 4K Blu-Rays on PCs. I'm not sure what other feature is involved here that would make sense in this use case. I mean, yes, PSP also can be used to enforce BIOS signing requirements, but the whole point of Coreboot is to be able to have a Free-as-in-freedom BIOS that you can legally and technically modify. If you wanted to do Apple-style secure local signing[0] of the modified BIOS, that'd be cool, but as far as I'm aware that's not on offer. So the PSP is a security deadweight for the kinds of techies that would care about Free BIOS. Furthermore, there IS a very large customer that has wanted to remove these kinds of secure enclaves from their systems: the US government, specifically the National Security Administration[1]. There's a special configuration option in Intel ME to turn off everything but basic system bring-up. Why would the NSA want to turn off "privacy and security software" on their own machines? Well, again, the whole "wipe a compromised system without the malware being able to resist" thing implies that this isn't merely a security enclave, but a backdoor that could be compromised by a third-party. If you aren't specifically using that remote management stuff, you want the ME to be as brain-dead as possible. [0] On Apple silicon that is fused for Macs, the bootloader allows booting operating systems that are signed with the Secure Enclave's local key. There is no unsigned boot; instead the Owner account on macOS has to authorize signing a new third-party OS in a special recovery mode in order to install, say, Linux or whatever. Oh, and Apple doesn't actually give the Secure Enclave the ability to mess with the main application processor. It's more akin to a TPM, where it can withhold encryption keys from the regular OS but it can't actively snoop on it. So they also understand why PSP/ME were bad ideas. [1] https://www.csoonline.com/article/3220476/researchers-say-now-you-too-can-disable-intel-me-backdoor-thanks-to-the-nsa.html https://www.csoonline.com/article/3220476/researchers-say-no...
    - gray_charger 4y ago
  - parker_mountain 4y ago
    >In fact, privacy and security software may be hindered without something like PSP or SGX. While this is technically correct, trust and transparency are key aspects - something that PSP is missing.
  - rurban 4y ago
    As trusted execution env has nothing to do with sniffing network traffic or have access to main memory, IO, CPU registers . So why does it do so? Because it's merely a backdoor, not a trusted enclave.
    - gray_charger 4y ago
      A TEE has nothing to do with any of that. A TEE is a CPU feature that generates a physically separate area of memory that no other process can access to protect sensitive data from even the OS (in case of compromise).
- akira2501 4y ago
  > Is it a backdoor if the owner put it there deliberately to be able to detect regular OS-level viruses? Yes. Unless the owner has a perfect guarantee that they will be the only ones who can use it and the will be aware of it every time it is used. The likelihood of this being true in the given environment is next to zero. They own it, though. They're free to fool themselves about it if they like.
  - wjnc 4y ago
    In your definition - what’s the de difference between a front door and a back door? Even front doors don’t seem to meet your standard.
eigenform 4y ago
I don't think so - seems more likely that something like OpenSIL would need to talk to the PSP. The difference here [hopefully] is that those interfaces are documented. edit: ie. from the blog post, on the xSIM part: > "Provides a set of API services that initialize the platform host silicon. Most of the silicon initialization on AMD-based platforms is performed by embedded µControllers prior to x86 reset de-assertion."
gray_charger 4y ago
Why would you want to do away with AMD PSP? It's a trusted execution environment that privacy and security software (e.g. Signal) makes use of for it's confidentiality and integrity guarantees.
- codedokode 4y ago
  Because I don't need uncontrolled backdoors in my PC. By the way, my laptop has an option to disable PSP in BIOS but I don't understand how it works because PSP is still visible on the PCI bus as "encryption controller". > It's a trusted execution environment It is "trusted" only by manufacturers and cannot be controlled by the user. Why cannot it be controlled by the user? Probably because it is intented to be used as a backdoor or to report users who install pirated software, or download unapproved materials etc.
  - Dalewyn 4y ago
    >Why cannot it be controlled by the user? Probably because it is intented to be used as a backdoor or to report users who install pirated software, or download unapproved materials etc. I have a simpler answer that doesn't require inherent malice: To keep out hostiles that have control over the computer, be that virtually or physically. You can't compromise what you can't access. Personally, I understand the concerns behind ME and PSP and am not particularly concerned. I trust Intel and AMD to not fuck with me, else why would I buy their processors? If I don't trust the ME/PSP because I don't trust Intel/AMD, I certainly can't trust the rest of their processors either.
    - badsectoracula 4y ago
      > else why would I buy their processors? To run software that require them?
    - codedokode 4y ago
      There are several points that make all this look suspicious: - first, ME/PSP do not follow minimum privileges principle. They have access to DRAM and network interfaces, so they can bypass restrictions set by OS and firewall. Does that make system more secure? I would say it is the opposite. They make the system less secure: for example, if there is a vulnerability in those modules then the whole system can be compromised and it will be difficult to detect using antivirus products. - second, firmware for ME/PSP is encrypted. Why is it done so? To prevent user from knowing what it does. Why am I not allowed to know how my computer works? Based on this, I can assume that intended purpose of this "trusted" modules is to implement user-hostile features like: DRM, software license checking, reporting illegal content, device fingerprinting, providing unauthorised remote access and so on.
yarg 4y ago
Be better to take control of it, and run it as a chunk of your hypervisor. (This is only possible if there's support for custom signing of device control. Cloud environments need to know that the security core is under the control of vendor signed firmware. (This provides cloud service providers with the inability to read their customers data and the customers with security.))

deleted 4y ago

[deleted]

oneplane 4y ago

Probably not, both because the PSP can be part of the SIL bringup which you statically link anyway, and because plenty of business customers want a Secure Enclave and the legal world is having a hard time getting paperwork to suggest it's both secure and open at the same time.

kmeisthax 4y ago

No, and you can't remove the PSP without rearchitecturing the processor. However, they could release a PSP firmware that just loads the x86 cores with your chosen BIOS and then halts. Businesses that want their systems to have management backdoors[0] can use the PSP firmware that implements that functionality, while users that care about Free boot chains can use the minimized firmware. [0] Is it a backdoor if the owner put it there deliberately to be able to detect regular OS-level viruses?

gray_charger 4y ago
PSP is a trusted execution environment not a remote management platform. There is no reason anyone should want to remove this from a privacy perspective. In fact, privacy and security software may be hindered without something like PSP or SGX.
- the8472 4y ago
  Perhaps if you could replace the trust root with your own. But as they are now it's the manufacturer that's in control.
  - mjg59 4y ago
    If you don't trust the manufacturer of your CPU, how do you trust any of the software running on that CPU?
    - ploxiln 4y ago
      Well, you don't have that much choice of CPU manufacturers, if you want a 65W+ performance class CPU, so you do the best you can. But anyway, there are many manufacturers that were happy to sell widgets without internet-connected software, and compete on the quality and price of those widgets in a fairly honest way. But when it became possible to embed software that can send data to the internet somehow, well various departments just could not resist demanding their engineers do so. Support costs can be massively reduced if you can just see what the stupid user did and remote in with the backdoor key and fix their misconfigured router/vpn/appliance (true story). And your marketing and product-planning teams are just severely hobbled by not having all the telemetry they can dream of, there's just millions wasted on team salaries and marketing spend if they can't get that user data sent to the SAAS marketing/crm tool they want. But when a car didn't have internet-connected computers in it, they just had to do without. We trust CPU manufacturers to act like reasonable companies. They make some good stuff, that's how they make money. They're not fly-by-night ventures. They can't risk the huge investments in their brand and their business. And they're not malicious spies trying to screw with you via very tricky microcode. But if they can conveniently put some value-add in the hidden support cpu because the marketing or support team really needed it ...
      - mjg59 4y ago
        The PSP is in the CPU, not the motherboard chipset, and doesn't have any access to the network. You can't get commands to it bypassing the main CPU.
    - the8472 4y ago
      It's about the continued leverage they have by holding the key after you bought the CPU. They could be forced by secret court to sign backdoored firmware. And of course you can't load your own firmware, only whatever they release and sign. If they're generous they'll release a stripped-down version, sure, but that's still their choice, not yours.
- justinclift 4y ago
  "Trusted by whom" is the problem. If the end user was in control of the PSP, that'd be great. :) However that's not the case. :(
  - gray_charger 4y ago
    If the end user was "in control" of the PSP that'd defeat the purpose. These features are supposed to remain a secure enclave even if the machine is compromised.
    - justinclift 4y ago
      Yeah, that's clearly not even fit for purpose by design. At least from the perspective of end users. :) Thinking about it a bit more, it also seems to be at odds with how security in the world works. Is there any case of having equipment be in the hands of end users for unlimited time (and without supervision), where the security doesn't get cracked? Once a single exploitable bug in the implementation is discovered, the whole thing becomes useless. Perhaps worse than useless, once malware starts to embed itself in the PSP.
- kmeisthax 4y ago
  So, if I remember correctly AMD PSP started out as a response to Intel ME, whose main selling point at the time was that businesses could remote into a compromised system and wipe malware without the malware being able to fight back. PSP also enables a few other things like encrypted virtualization - being able to lock AWS's staff out of the contents of my VMs' memory. That sort of feature isn't really useful to individual consumers. SGX is an interesting case since Intel actually axed the feature a year ago. The only thing it did was enable more DRM for 4K Blu-Rays, and Hollywood's response to that feature going away has been to just refuse to let you play 4K Blu-Rays on PCs. I'm not sure what other feature is involved here that would make sense in this use case. I mean, yes, PSP also can be used to enforce BIOS signing requirements, but the whole point of Coreboot is to be able to have a Free-as-in-freedom BIOS that you can legally and technically modify. If you wanted to do Apple-style secure local signing[0] of the modified BIOS, that'd be cool, but as far as I'm aware that's not on offer. So the PSP is a security deadweight for the kinds of techies that would care about Free BIOS. Furthermore, there IS a very large customer that has wanted to remove these kinds of secure enclaves from their systems: the US government, specifically the National Security Administration[1]. There's a special configuration option in Intel ME to turn off everything but basic system bring-up. Why would the NSA want to turn off "privacy and security software" on their own machines? Well, again, the whole "wipe a compromised system without the malware being able to resist" thing implies that this isn't merely a security enclave, but a backdoor that could be compromised by a third-party. If you aren't specifically using that remote management stuff, you want the ME to be as brain-dead as possible. [0] On Apple silicon that is fused for Macs, the bootloader allows booting operating systems that are signed with the Secure Enclave's local key. There is no unsigned boot; instead the Owner account on macOS has to authorize signing a new third-party OS in a special recovery mode in order to install, say, Linux or whatever. Oh, and Apple doesn't actually give the Secure Enclave the ability to mess with the main application processor. It's more akin to a TPM, where it can withhold encryption keys from the regular OS but it can't actively snoop on it. So they also understand why PSP/ME were bad ideas. [1] https://www.csoonline.com/article/3220476/researchers-say-now-you-too-can-disable-intel-me-backdoor-thanks-to-the-nsa.html https://www.csoonline.com/article/3220476/researchers-say-no...
  - gray_charger 4y ago
- parker_mountain 4y ago
  >In fact, privacy and security software may be hindered without something like PSP or SGX. While this is technically correct, trust and transparency are key aspects - something that PSP is missing.
- rurban 4y ago
  As trusted execution env has nothing to do with sniffing network traffic or have access to main memory, IO, CPU registers . So why does it do so? Because it's merely a backdoor, not a trusted enclave.
  - gray_charger 4y ago
    A TEE has nothing to do with any of that. A TEE is a CPU feature that generates a physically separate area of memory that no other process can access to protect sensitive data from even the OS (in case of compromise).
akira2501 4y ago
> Is it a backdoor if the owner put it there deliberately to be able to detect regular OS-level viruses? Yes. Unless the owner has a perfect guarantee that they will be the only ones who can use it and the will be aware of it every time it is used. The likelihood of this being true in the given environment is next to zero. They own it, though. They're free to fool themselves about it if they like.
- wjnc 4y ago
  In your definition - what’s the de difference between a front door and a back door? Even front doors don’t seem to meet your standard.

eigenform 4y ago

I don't think so - seems more likely that something like OpenSIL would need to talk to the PSP. The difference here [hopefully] is that those interfaces are documented. edit: ie. from the blog post, on the xSIM part: > "Provides a set of API services that initialize the platform host silicon. Most of the silicon initialization on AMD-based platforms is performed by embedded µControllers prior to x86 reset de-assertion."

gray_charger 4y ago

Why would you want to do away with AMD PSP? It's a trusted execution environment that privacy and security software (e.g. Signal) makes use of for it's confidentiality and integrity guarantees.

codedokode 4y ago
Because I don't need uncontrolled backdoors in my PC. By the way, my laptop has an option to disable PSP in BIOS but I don't understand how it works because PSP is still visible on the PCI bus as "encryption controller". > It's a trusted execution environment It is "trusted" only by manufacturers and cannot be controlled by the user. Why cannot it be controlled by the user? Probably because it is intented to be used as a backdoor or to report users who install pirated software, or download unapproved materials etc.
- Dalewyn 4y ago
  >Why cannot it be controlled by the user? Probably because it is intented to be used as a backdoor or to report users who install pirated software, or download unapproved materials etc. I have a simpler answer that doesn't require inherent malice: To keep out hostiles that have control over the computer, be that virtually or physically. You can't compromise what you can't access. Personally, I understand the concerns behind ME and PSP and am not particularly concerned. I trust Intel and AMD to not fuck with me, else why would I buy their processors? If I don't trust the ME/PSP because I don't trust Intel/AMD, I certainly can't trust the rest of their processors either.
  - badsectoracula 4y ago
    > else why would I buy their processors? To run software that require them?
  - codedokode 4y ago
    There are several points that make all this look suspicious: - first, ME/PSP do not follow minimum privileges principle. They have access to DRAM and network interfaces, so they can bypass restrictions set by OS and firewall. Does that make system more secure? I would say it is the opposite. They make the system less secure: for example, if there is a vulnerability in those modules then the whole system can be compromised and it will be difficult to detect using antivirus products. - second, firmware for ME/PSP is encrypted. Why is it done so? To prevent user from knowing what it does. Why am I not allowed to know how my computer works? Based on this, I can assume that intended purpose of this "trusted" modules is to implement user-hostile features like: DRM, software license checking, reporting illegal content, device fingerprinting, providing unauthorised remote access and so on.

yarg 4y ago

Be better to take control of it, and run it as a chunk of your hypervisor. (This is only possible if there's support for custom signing of device control. Cloud environments need to know that the security core is under the control of vendor signed firmware. (This provides cloud service providers with the inability to read their customers data and the customers with security.))