Re: [Anima] creating iDevID certs with openssl

[Kent Watsen <[e-mail]>]

> On the openssl-user list, the claim was made that concatinating DER 
> certs for a cert chain like you do with PEM does not work with 
> applications.  You have to use PKCS#12, but that includes the private 
> key and is passworded.  I should be able to get the pointer to Viktor's 
> post about this.

Concatenating PEM encodings into a single file is a hack, albeit a super
convenient one.  Instead of PKCS#12, have you looked into PKCS#7? - this
is what is used in the netconf-zerotouch draft for binary certificate
chains.


> Here is where you'd find objects in BRSKI:
>
> 1) TLS ClientCertificate.
>     This should be just the IDevID blob, and in TLS, it's in DER format,
>     if the Registrar needs anything else in the chain, it must chase them down
>     itself.

FWIW, the netconf-zerotouch draft specifies that the device possesses the
IDevID cert *and* all the intermediate certs leading to the manufacturer's
well-known trust-anchor, all of which it provides during crypto handshake.


> 2) TLS ServerCertificate.
>     https://tools.ietf.org/html/rfc5246#section-7.4.2
>       Note: PKCS #7 [PKCS7] is not used as the format for the certificate
>       vector because PKCS #6 [PKCS6] extended certificates are not used.
>       Also, PKCS #7 defines a SET rather than a SEQUENCE, making the task
>       of parsing the list more difficult.

I don't understand how this relates to PKCS#6.  True about the SET, but this
is minor relative to the tradeoffs.  Can you say some more about this?


> 3) The plege's Voucher Request may be signed using JOSE (using the IDevID)
>     The IDevID is not sent, it's the one from ClientCertificate.
>
> 4) The registar's Voucher Request may be signed using JOSE, using the
>     Domain Owner's key.  That might not be the same key the Registrar uses
>     to form the EST connection to the MASA (if the Registrar uses client
>     authentication at all).
>     The Domain Owner is within the pinned-domain-cert field.
>     We define it as being DER binary.  In JSON format, that turns into base64
>     encoded.  The reason we go there is that we do not want the
>     ----BEGIN... stuff in there for JSON, in another encoding (CBOR), binary
>     is just fine.

Correct, putting PEM-text into protocols is inappropriate.


> 5) The resulting voucher also uses pinned-domain-cert as well, now signed
>     by the MASA.
>
>      > What format are the various bootstrap objects (eg vouchers)?  Has
>      > anyone built any of these for PoC?
>
> PoC?

Aren't the formats defined in the drafts?  E.g., the voucher draft
says it’s a PKCS#7.

Regarding PoC, here's some code to create/validate vouchers: 
https://github.com/netconf-wg/zero-touch/tree/master/openssl-test.


K.