using OpenPGP card as an X.509 CA?
daniel at pocock.com.au
Tue Jun 25 17:32:22 CEST 2013
On 25/06/13 15:28, Werner Koch wrote:
> On Tue, 25 Jun 2013 12:43, daniel at pocock.com.au said:
>> I understand the OpenPGP card can hold one X.509 certificate
> Actually the card does not hold any certifciate but merely the keys and
> OpenPGP fingerprints of the certificates. You can very well use such a
> key to create an X.509 certifciate:
> $ gpgsm --gen-key
> gpgsm: NOTE: THIS IS A DEVELOPMENT VERSION!
> gpgsm: It is only intended for test purposes and should NOT be
> gpgsm: used in a production environment or with production keys!
> Please select what kind of key you want:
> (1) RSA
Should this option work without a smart card, e.g. creating a key in the
local home directory?
When I run it, it takes me through the questions, asks me to confirm the
cert details and then fails with
gpgsm: line 1: key generation failed: Unsupported certificate
> (2) Existing key
> (3) Existing key from card
> Your selection? 3
> Serial number of the card: D2760001240102000005000001230000
> Available keys:
> (1) C003409A7489993713D22A10DD0604853FEE33F8 OPENPGP.1
> (2) C91C9AA0731D82B3B3191EA68478EAD4B5069EE8 OPENPGP.2
> (3) EC9663F3E82CEAC9734212CF13AAAA1A63B0F7DC OPENPGP.3
> Your selection?
>> Can this be used in practice to run an in-house CA to sign other X.509
>> certificates, e.g. for small VPN setups?
> There is no software to manage a CA but you can do it manually with gpgsm.
I found the command "--sign" in the man page, but there is no example.
Should "--sign" take a CSR as input and generate a cert as output and
could you provide an example? Or is some intermediate processing needed
to convert the CSR into something the gpgsm can sign?
>> Also, can the X.509 cert on the OpenPGP card be used with StrongSwan (as
>> a client or server cert for VPN)?
> Depends on what interface is supported. If it uses pkcs#11 you may want
> to checkout Scute.
strongSwan reportedly works with PKCS#11 / OpenSC, it's hard for me to
understand if Scute will work but I don't mind trying it.
I notice the Scute "Features and Limitations" page says it only works
with 36 byte signatures for MD5 and SHA1 hashes. Many people have now
moved to SHA2 or stronger hashes
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