4 ms·

I highly doubt this key was on a HSM. I keep being amazed by news about keys being stolen which seemingly should have been on a HSM.

callalex 3y ago
HSM?
- 0xC0ncord 3y ago
  A hardware security module (HSM) is a physical computing device that safeguards and manages secrets (most importantly digital keys), performs encryption and decryption functions for digital signatures, strong authentication and other cryptographic functions. These modules traditionally come in the form of a plug-in card or an external device that attaches directly to a computer or network server. A hardware security module contains one or more secure cryptoprocessor chips. https://en.wikipedia.org/wiki/Hardware_security_module https://en.wikipedia.org/wiki/Hardware_security_module
- pieterr 3y ago
  Hardware Security Module (HSM).
- jshmrsn 3y ago
  Looked it up, appears to be Hardware Security Module.
- whartung 3y ago
  Hardware Security Module. A tamper resistant piece of hardware that does key management as well as encryption services. Essentially once a key is installed (or generated) it never sees the light of day again.
- taspeotis 3y ago
  Hardware Security Module
CalmStorm 3y ago
One of the most popular HSM is Thales Luna Network HSM, which can perform 20,000 ECC operations per second [1]. Even with the size of Azure AD, Microsoft may not need a lot of HSMs for signing purpose. HSMs are not particularly easy to manage though, maybe that is one of reasons they are not used as much as they should be. [1] https://cpl.thalesgroup.com/encryption/hardware-security-modules/network-hsms https://cpl.thalesgroup.com/encryption/hardware-security-mod...
- deleted 3y ago
  [deleted]
kune 3y ago
There are two scenarios: First: Microsoft uses the JWT signing keys in memory and the attacker were able to get access to it by injecting code or get access to the memory image of such a process. Second: Microsoft actually uses HSMs but has to distribute the keys geographically and the attackers were able to get access to the key this way. The first scenario is more likely, but you cannot exclude the second as well.
- 8191 3y ago
  As for each purpose several keys exist, according to the article, geographic key distribution wouldn’t be necessary anyway.
wahern 3y ago
Keys on an HSM are difficult to use by a team. Network attached HSMs are a thing but they have poor integration with the toolchains developers often use. Recently I was able to write my own ideal tool to help bridge the gap between toolchains and hardware secure enclaves: https://keymux.com https://keymux.com
- mike_d 3y ago
  Keys like this should never be used by a team. They should never touch a developer or devops workstation. They exist in prod only inside of an HSM. High performance HSMs capable of handling 10k+ transactions/second are well within the price range of a well funded startup.
  - wahern 3y ago
    > Keys like this should never be used by a team. They should never touch a developer or devops workstation. That's the point of KeyMux: keys never leave a secure enclave. In fact, KeyMux has no logic to load private keys or to perform key operations in-memory, except in the context of ephemeral TLS. The TLS layer does support using HSM keys for mTLS authentication, so you can use a security token for peer mTLS authentication to a network attached HSM. That's the whole point--you can use all the tools built and commonly used with in-memory keys, but using enclaved keys, instead. A follow-on idea I'd like to spend time on, if I have the chance, is to write modules for Vault and/or some KMIP implementation that integrate with the app so that authorization for key operations on a networked-attached key store require the consent of multiple parties (with that consent using local secure enclave-based authentication, of course). So, for example, if you're going to roll a release, one developer or an automated pipeline submits the request but the signing awaits confirmation from other team members.
  - tatersolid 3y ago
    > High performance HSMs capable of handling 10k+ transactions/second are well within the price range of a well funded startup. Microsoft knows this, and even offers HSMs as a cloud service. HSMs simply don’t scale up to something the size of azure AD. Even if you could use 10K+ of them in a global cluster, copying keys between HSMs inherently exposes the master keys anyway. And how do you secure access to the HSMs, with another secret shared on every validation server? Turtles all the way down.

callalex 3y ago

HSM?

0xC0ncord 3y ago
A hardware security module (HSM) is a physical computing device that safeguards and manages secrets (most importantly digital keys), performs encryption and decryption functions for digital signatures, strong authentication and other cryptographic functions. These modules traditionally come in the form of a plug-in card or an external device that attaches directly to a computer or network server. A hardware security module contains one or more secure cryptoprocessor chips. https://en.wikipedia.org/wiki/Hardware_security_module https://en.wikipedia.org/wiki/Hardware_security_module
pieterr 3y ago
Hardware Security Module (HSM).
jshmrsn 3y ago
Looked it up, appears to be Hardware Security Module.
whartung 3y ago
Hardware Security Module. A tamper resistant piece of hardware that does key management as well as encryption services. Essentially once a key is installed (or generated) it never sees the light of day again.
taspeotis 3y ago
Hardware Security Module

CalmStorm 3y ago

One of the most popular HSM is Thales Luna Network HSM, which can perform 20,000 ECC operations per second [1]. Even with the size of Azure AD, Microsoft may not need a lot of HSMs for signing purpose. HSMs are not particularly easy to manage though, maybe that is one of reasons they are not used as much as they should be. [1] https://cpl.thalesgroup.com/encryption/hardware-security-modules/network-hsms https://cpl.thalesgroup.com/encryption/hardware-security-mod...

deleted 3y ago
[deleted]

kune 3y ago

There are two scenarios: First: Microsoft uses the JWT signing keys in memory and the attacker were able to get access to it by injecting code or get access to the memory image of such a process. Second: Microsoft actually uses HSMs but has to distribute the keys geographically and the attackers were able to get access to the key this way. The first scenario is more likely, but you cannot exclude the second as well.

8191 3y ago
As for each purpose several keys exist, according to the article, geographic key distribution wouldn’t be necessary anyway.

wahern 3y ago

Keys on an HSM are difficult to use by a team. Network attached HSMs are a thing but they have poor integration with the toolchains developers often use. Recently I was able to write my own ideal tool to help bridge the gap between toolchains and hardware secure enclaves: https://keymux.com https://keymux.com

mike_d 3y ago
Keys like this should never be used by a team. They should never touch a developer or devops workstation. They exist in prod only inside of an HSM. High performance HSMs capable of handling 10k+ transactions/second are well within the price range of a well funded startup.
- wahern 3y ago
  > Keys like this should never be used by a team. They should never touch a developer or devops workstation. That's the point of KeyMux: keys never leave a secure enclave. In fact, KeyMux has no logic to load private keys or to perform key operations in-memory, except in the context of ephemeral TLS. The TLS layer does support using HSM keys for mTLS authentication, so you can use a security token for peer mTLS authentication to a network attached HSM. That's the whole point--you can use all the tools built and commonly used with in-memory keys, but using enclaved keys, instead. A follow-on idea I'd like to spend time on, if I have the chance, is to write modules for Vault and/or some KMIP implementation that integrate with the app so that authorization for key operations on a networked-attached key store require the consent of multiple parties (with that consent using local secure enclave-based authentication, of course). So, for example, if you're going to roll a release, one developer or an automated pipeline submits the request but the signing awaits confirmation from other team members.
- tatersolid 3y ago
  > High performance HSMs capable of handling 10k+ transactions/second are well within the price range of a well funded startup. Microsoft knows this, and even offers HSMs as a cloud service. HSMs simply don’t scale up to something the size of azure AD. Even if you could use 10K+ of them in a global cluster, copying keys between HSMs inherently exposes the master keys anyway. And how do you secure access to the HSMs, with another secret shared on every validation server? Turtles all the way down.