[openssl-users] Another problem with openssl x509 -req -- default_enddate

Robert Moskowitz rgm at htt-consult.com
Wed Aug 30 15:57:08 UTC 2017

On 08/30/2017 10:33 AM, Viktor Dukhovni wrote:
> On Wed, Aug 30, 2017 at 06:03:03AM -0400, Robert Moskowitz wrote:
>> I woke up a little clearer head, and realized, that a truly
>> constrained device won't even bother with DER, but just store the raw
>> keypair.
> FWIW, Apple's boot firmware stores the signature key as the raw
> RSA key bits in little-endian form for efficient computation on
> Intel CPUs.  No PEM or ASN.1 in sight.
> Similarly, there's no ASN.1 in the DNSSEC DNSKEY RDATA format.
> For RSA just the key and exponent octets:
>      $ echo $(dig +short +nosplit -t dnskey . | grep -w 256 | awk '{print $NF}' | openssl base64 -A -d | hexdump -ve '/1 "%02x"')
>      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
> The "03" is the exponent length (limited to 255 octets), the "10
> 00 01" is the usual F_4 (65537) exponent, and the remaining 512
> nibbles are the RSA modulus.
> So indeed, you'd not be the first to consider a special-purpose
> concise format.  It is somewhat surprising that the applications
> you're considering use X.509 certificates at all, rather than just
> raw public keys.  With expiration times in the year "9999", the
> extra bloat of certificates is perhaps just useless baggage.
> Admittedly, I don't know how the security model in question relates
> to the real-world constraints of the supply chain, who gets to sign
> certificates for devices allowed to participate, and whether a
> certificateless public key database might have been a realistic
> option.

I am the author of HIP (rfc 7401) and to a large extent, raw public keys 
for Identity.  I started this work in January '99, before most of the 
current stuff using raw keys came around.  I know that Apple parallel 
developed much of their work.  Stewart Cheshire has said that if he had 
found the time to read HIP, he would have used it for the call home 
function.  And I know all about DNSKEY, as a few years into HIP, we 
chose to use the DNSKEY format in the HI parameter payload, dropping our 
own format.

I also worked with Sigma Design on Zwave 2.0 which uses raw EC25519 keys.

But not everyone agrees with me on raw keys, and I do recognize the need 
of 3rd party identity assertions.  And this is, to a large measure, what 
IEEE 802.1AR-2009 Secure Identities offers.  But 1AR is only about the 
Identities, and not how to manage and bootstrap from iDevIDs to 
lDevIDs.  The IETF workgroup, ANIMA is working on this.  And Michael 
Richardson, who just joined this list, is one of the authors on those 
documents.  Oh, and NETCONF is working on it for network infrastructure 
devices with their 'zero touch' drafts. Of course those are NOT 
constrained devices...

Getting 802.1AR-2009 does require an IEEE login, but is free thanks to 
us IEEE 802 meeting attendees paying a bit extra to IEEE to make our 
docs free 6 months after publication.  Of course the addendum that is in 
final prep is NOT available free (to non-attendees), but the changes do 
not impact this discussion.

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