Import keys & certificates?


#1

Hello,

Is it possible to import a keypair and certificates on the HSM key ? We’d like to start with the HSM but we already have keys and certificates being used in the field. So it’s too late to ask the key to generate those.

TIA

J


#2

Sorry for reviving this old thread.

We want to do the same.
Is there a solution?

BR
Sascha


#3

Hi!

Please check would this be helpful to you: https://www.nitrokey.com/documentation/smime-email-encryption


#4

You can use the Smart Card Shell [1] to import RSA and ECC keys from PKCS#12. In order to do that, you need

  1. Install the Java Cryptography Extension (JCE) Unlimited Strength Jurisdiction Policy Files 8 Download from [2], as we use AES-256 for key import (see [3] for details)
  2. Generate in SCSH a DKEK share for import
  3. Initialize the device with a DKEK share
  4. Import DKEK share
  5. Select Import PKCS#12 and select the DKEK share file

The SmartCard-HSM supports only encrypted import, so you need to define a DKEK for import.

RSA keys with 3072 or 4096 bit can only be imported in private exponent / modulus format. There is a work-around available to convert from CRT to PE/M format [4].

[1] https://www.openscdp.org/scsh3/index.html
[2] https://www.oracle.com/technetwork/java/javase/downloads/jce8-download-2133166.html
[3] https://github.com/CardContact/scsh-scripts/issues/4
[4] https://github.com/CardContact/scsh-scripts/issues/5


#5

@sc-hsm Does this mean that I need to keep the DKEK around (instead of in a safe place) if I need to regularly import keys into the HSM?

It seems to me that allowing unencrypted import (in addition to via DKEK) is not a security problem.


#6

We generally advice to generate keys in the device and use key backup and restore to keep a protected copy. In that case you need to keep the DKEK in a safe place, ideally using a key management procedure with DKEK share, key custodians, proper protocols etc.

Why would you use a hardware token, if you keep the key in plain somewhere else ? That’s the whole purpose of using a hardware token, to ensure that no copies of the key can be taken unless allowed by a procedure under control of key custodians.

Importing plain keys may work for home use scenarios, but it’s nothing that would be done in a professional application.


#7

The use case I was thinking about is for escrow of keys used for email encryption. One copy is in the possession of each employee (on a Nitrokey Start, or a TPM) and another is kept in a central (secure) place. For the second copy I’d like to use the HSM, ideally set up in a way that no single person can use the escrow keys alone.

For this, I’d need a way to import new keys into both the HSM and the users token after creating the key in a offline system. Of course I could use a HSM for each user, but that seems overkill.