From #Rationale (concerning the backup option that most commercial HSMs allow):
>> I do am of the opinion that HSM's should not offer this option (getting access to the private key).
It boils down to your opinion then. Within the industry "HSM" is pretty much synonimous of compliance to FIPS 140, which allows key extraction even at its highest level (Level 4), provided that the risk is mitigated appropriately (E.g. by means of a split secret policy and more in general by means of all the security measures that go beyond the technologic ones provided by the HSM itself).
You are free to keep your opinion but the statement that such possibility "still beats the purpose of the HSM though" is not shared by many people.
Also (again concerning the backups):
>> Since it requires so many steps and so much access, I don't think this is a huge risk, but a rather nice convinience.
No, it is not a convenience. It is a manner to mitigate the risk of denial of service one may cause by purposedly destroying or stealing your HSM.
>> I've seen multiple big-name HSM's where their support was able to decrypt the key and transfer it to another HSM model, but since I've signed an NDA I cannot tell which ones that were.
I challenge this statement: I deal with most big-name HSMs (and there are not that many) and none of them can do this.
I do know because that is a risk we explicitly check for when evaluating one.
In certain cases you may manipulate their API to extract some keys if they were generated internally in a certain way, but that is a known, public problem in the industry.
> You are free to keep your opinion but the statement that such possibility "still beats the purpose of the HSM though" is not shared by many people.
I'm aware of the FIPS standard, therefore I worded the piece as my opinion. I think it's better to be able to rotate the keys then to restore to the same/other device. Since extraction might lead to decryption. I do also know that software-wise that is an inconvinience and in some cases not possible. Bur still, a device that protects private keys should not give them up. As you say, my opinion.
> No, it is not a convenience. It is a manner to mitigate the risk of denial of service one may cause by purposedly destroying or stealing your HSM.
Stealing should be protected by the tamper-protection, thus causing a wipe of the device. In that case you might have a bigger problem, someone has access to your datacenter and racks. In that case a backup is very welcome. (I do find it a hard problem where the two sides, no backup, a backup, both are equally important.
> I challenge this statement: I deal with most big-name HSMs (and there are not that many) and none of them can do this. I do know because that is a risk we explicitly check for when evaluating one.
We've had a situation were two different revisions of the same device were not able to load a wrapped key. Support flew in and told us they could fix in in a new firmware in three months, no guarantees. We installed screen recorders and a keylogger, since they were on our production env (audit logging). They did, with undocumented commands, export the key from the device in an unencrypted format and loaded it into the other model so that we could continue our operation. Reviewing the recording and the logs showed that the commands did also work on other HSM's we had. I'm still under NDA so I cannot talk about which brand or model specific.
> They did, with undocumented commands, export the key from the device in an unencrypted format and loaded it into the other model so that we could continue our operation.
NDA or not, that company should be put out of business. Essentially they've backdoored that HSM.
Assuming it is true this is far bigger news than the article you wrote.
>> I do am of the opinion that HSM's should not offer this option (getting access to the private key).
It boils down to your opinion then. Within the industry "HSM" is pretty much synonimous of compliance to FIPS 140, which allows key extraction even at its highest level (Level 4), provided that the risk is mitigated appropriately (E.g. by means of a split secret policy and more in general by means of all the security measures that go beyond the technologic ones provided by the HSM itself).
You are free to keep your opinion but the statement that such possibility "still beats the purpose of the HSM though" is not shared by many people.
Also (again concerning the backups):
>> Since it requires so many steps and so much access, I don't think this is a huge risk, but a rather nice convinience.
No, it is not a convenience. It is a manner to mitigate the risk of denial of service one may cause by purposedly destroying or stealing your HSM.
>> I've seen multiple big-name HSM's where their support was able to decrypt the key and transfer it to another HSM model, but since I've signed an NDA I cannot tell which ones that were.
I challenge this statement: I deal with most big-name HSMs (and there are not that many) and none of them can do this. I do know because that is a risk we explicitly check for when evaluating one.
In certain cases you may manipulate their API to extract some keys if they were generated internally in a certain way, but that is a known, public problem in the industry.