▲ 737 ▼ BitLocker encryption broken in less than 43 seconds with sub-$10 Raspberry Pi Pico — key can be sniffed when using an external TPM (www.tomshardware.com) submitted 2 years ago by throws_lemy@lemmy.nz to c/technology@lemmy.world 69 comments fedilink hide all child comments
[–] fmstrat@lemmy.nowsci.com 31 points 2 years ago (2 children) Say it with me now: LUUUUUKS permalink fedilink source hideshow 4 child comments replies: [–] baseless_discourse@mander.xyz 36 points 2 years ago* (last edited 2 years ago) (1 child) LUKS is still vulnerable to this attack if you enable autodecrypt using TPM. This attack is based on the vulnerability that the CPU and TPM communicates uses plain text. And it is a pretty common attack against TPM: https://dolosgroup.io/blog/2021/7/9/from-stolen-laptop-to-inside-the-company-network SPI is a communication protocol for embedded systems and is extremely common amongst virtually all hardware. Due to its simplicity, there is no encryption option for SPI. Any encryption must be handled by the devices themselves. At the time of this writing BitLocker does not utilize any encrypted communication features of the TPM 2.0 standard, which means any data coming out of the TPM is coming out in plaintext, including the decryption key for Windows And apparently Linux is not doing too hot on this regard either: https://www.secura.com/blog/tpm-sniffing-attacks-against-non-bitlocker-targets As we can see, parameter encryption simply isn't used in practice, and except for safeboot none of the solutions enforce PIN/MFA by default. However, this attack is not viable for device with firmware based solution, like fTPM, Microsoft Pluton, secure enclave etc. in these case TPM is part of the cpu, hence have no exposed pins to sniff their connection. So if you don't want people with physical access to your computer (a thief or a evil maiden) to access everything on your disk, don't setup TPM auto decrypt. permalink fedilink source parent hideshow 2 child comments replies: [–] phoenixz@lemmy.ca 15 points 2 years ago (2 children) CPU communicates with TPM in plaintext Because of course permalink fedilink source parent hideshow 4 child comments replies: [–] Eufalconimorph@discuss.tchncs.de 7 points 2 years ago (1 child) CPU doesn't have any secure storage, so it can't encrypt or authenticate comms to the TPM. The on-CPU fTPMs are the solution, the CPU then has the secure storage. permalink fedilink source parent hideshow 2 child comments replies: [–] baseless_discourse@mander.xyz 2 points 2 years ago That make sense, CPU has no place to store private keys, since that is the functionality of TPM... Unless there is a firmware solution, which defeats the purpose of a standalone tpm. permalink fedilink source parent [+] baseless_discourse@mander.xyz 1 point 2 years ago* (last edited 2 years ago) [deleted] permalink fedilink source parent [–] HelloHotel@lemm.ee 15 points 2 years ago* (2 children) I wondered why LUUUUUKS didnt use the TPM, why do i have to put my password in... this is absolutely why. Edit: fixed spelling of LUUUUUKS permalink fedilink source parent hideshow 4 child comments replies: [–] cooopsspace@infosec.pub 4 points 2 years ago* Also yes you can, I wouldn't recommend it though. Maybe in addition to your password though. Wait until you see Dracut and Tang. permalink fedilink source parent [–] mlaga97@lemmy.mlaga97.space 3 points 2 years ago (1 child) What exactly is the point of full disk encryption if the system auto-unlocks on boot? permalink fedilink source parent hideshow 2 child comments replies: [–] rambling_lunatic@sh.itjust.works 1 point 2 years ago Protection against tampering, maybe? Bad excuse, but that is the logic I've heard. permalink fedilink source parent
[–] baseless_discourse@mander.xyz 36 points 2 years ago* (last edited 2 years ago) (1 child) LUKS is still vulnerable to this attack if you enable autodecrypt using TPM. This attack is based on the vulnerability that the CPU and TPM communicates uses plain text. And it is a pretty common attack against TPM: https://dolosgroup.io/blog/2021/7/9/from-stolen-laptop-to-inside-the-company-network SPI is a communication protocol for embedded systems and is extremely common amongst virtually all hardware. Due to its simplicity, there is no encryption option for SPI. Any encryption must be handled by the devices themselves. At the time of this writing BitLocker does not utilize any encrypted communication features of the TPM 2.0 standard, which means any data coming out of the TPM is coming out in plaintext, including the decryption key for Windows And apparently Linux is not doing too hot on this regard either: https://www.secura.com/blog/tpm-sniffing-attacks-against-non-bitlocker-targets As we can see, parameter encryption simply isn't used in practice, and except for safeboot none of the solutions enforce PIN/MFA by default. However, this attack is not viable for device with firmware based solution, like fTPM, Microsoft Pluton, secure enclave etc. in these case TPM is part of the cpu, hence have no exposed pins to sniff their connection. So if you don't want people with physical access to your computer (a thief or a evil maiden) to access everything on your disk, don't setup TPM auto decrypt. permalink fedilink source parent hideshow 2 child comments replies: [–] phoenixz@lemmy.ca 15 points 2 years ago (2 children) CPU communicates with TPM in plaintext Because of course permalink fedilink source parent hideshow 4 child comments replies: [–] Eufalconimorph@discuss.tchncs.de 7 points 2 years ago (1 child) CPU doesn't have any secure storage, so it can't encrypt or authenticate comms to the TPM. The on-CPU fTPMs are the solution, the CPU then has the secure storage. permalink fedilink source parent hideshow 2 child comments replies: [–] baseless_discourse@mander.xyz 2 points 2 years ago That make sense, CPU has no place to store private keys, since that is the functionality of TPM... Unless there is a firmware solution, which defeats the purpose of a standalone tpm. permalink fedilink source parent [+] baseless_discourse@mander.xyz 1 point 2 years ago* (last edited 2 years ago) [deleted] permalink fedilink source parent
[–] phoenixz@lemmy.ca 15 points 2 years ago (2 children) CPU communicates with TPM in plaintext Because of course permalink fedilink source parent hideshow 4 child comments replies: [–] Eufalconimorph@discuss.tchncs.de 7 points 2 years ago (1 child) CPU doesn't have any secure storage, so it can't encrypt or authenticate comms to the TPM. The on-CPU fTPMs are the solution, the CPU then has the secure storage. permalink fedilink source parent hideshow 2 child comments replies: [–] baseless_discourse@mander.xyz 2 points 2 years ago That make sense, CPU has no place to store private keys, since that is the functionality of TPM... Unless there is a firmware solution, which defeats the purpose of a standalone tpm. permalink fedilink source parent [+] baseless_discourse@mander.xyz 1 point 2 years ago* (last edited 2 years ago) [deleted] permalink fedilink source parent
[–] Eufalconimorph@discuss.tchncs.de 7 points 2 years ago (1 child) CPU doesn't have any secure storage, so it can't encrypt or authenticate comms to the TPM. The on-CPU fTPMs are the solution, the CPU then has the secure storage. permalink fedilink source parent hideshow 2 child comments replies: [–] baseless_discourse@mander.xyz 2 points 2 years ago That make sense, CPU has no place to store private keys, since that is the functionality of TPM... Unless there is a firmware solution, which defeats the purpose of a standalone tpm. permalink fedilink source parent
[–] baseless_discourse@mander.xyz 2 points 2 years ago That make sense, CPU has no place to store private keys, since that is the functionality of TPM... Unless there is a firmware solution, which defeats the purpose of a standalone tpm. permalink fedilink source parent
[+] baseless_discourse@mander.xyz 1 point 2 years ago* (last edited 2 years ago) [deleted] permalink fedilink source parent
[–] HelloHotel@lemm.ee 15 points 2 years ago* (2 children) I wondered why LUUUUUKS didnt use the TPM, why do i have to put my password in... this is absolutely why. Edit: fixed spelling of LUUUUUKS permalink fedilink source parent hideshow 4 child comments replies: [–] cooopsspace@infosec.pub 4 points 2 years ago* Also yes you can, I wouldn't recommend it though. Maybe in addition to your password though. Wait until you see Dracut and Tang. permalink fedilink source parent [–] mlaga97@lemmy.mlaga97.space 3 points 2 years ago (1 child) What exactly is the point of full disk encryption if the system auto-unlocks on boot? permalink fedilink source parent hideshow 2 child comments replies: [–] rambling_lunatic@sh.itjust.works 1 point 2 years ago Protection against tampering, maybe? Bad excuse, but that is the logic I've heard. permalink fedilink source parent
[–] cooopsspace@infosec.pub 4 points 2 years ago* Also yes you can, I wouldn't recommend it though. Maybe in addition to your password though. Wait until you see Dracut and Tang. permalink fedilink source parent
[–] mlaga97@lemmy.mlaga97.space 3 points 2 years ago (1 child) What exactly is the point of full disk encryption if the system auto-unlocks on boot? permalink fedilink source parent hideshow 2 child comments replies: [–] rambling_lunatic@sh.itjust.works 1 point 2 years ago Protection against tampering, maybe? Bad excuse, but that is the logic I've heard. permalink fedilink source parent
[–] rambling_lunatic@sh.itjust.works 1 point 2 years ago Protection against tampering, maybe? Bad excuse, but that is the logic I've heard. permalink fedilink source parent