query on key usage OIDs

[Kyle Hamilton]

Also, OIDs for extendedKeyUsage can be defined per-application, so
there's no way to compile a full list of them.

-Kyle H

On Fri, Jul 16, 2021 at 4:23 AM Viktor Dukhovni
<openssl-users at dukhovni.org> wrote:
>
> > On 15 Jul 2021, at 11:55 pm, SIMON BABY <simonkbaby at gmail.com> wrote:
> >
> > I am looking for openssl APIs to get all the OIDs associated with user certificate Key usage extension. For example my sample Key usage extension from the certificate is below:
> > X509v3 extensions:
> >             X509v3 Key Usage: critical
> >                 Digital Signature, Key Encipherment
> >
> > I am looking for the APIs used to get the OIDs associated with  Digital Signature and Key Encipherment from the certificate.
>
> There are no keyUsage OIDs, the field is a bitstring:
>
>    https://datatracker.ietf.org/doc/html/rfc5280#section-4.2.1.3
>
>       id-ce-keyUsage OBJECT IDENTIFIER ::=  { id-ce 15 }
>
>       KeyUsage ::= BIT STRING {
>            digitalSignature        (0),
>            nonRepudiation          (1), -- recent editions of X.509 have
>                                         -- renamed this bit to contentCommitment
>            keyEncipherment         (2),
>            dataEncipherment        (3),
>            keyAgreement            (4),
>            keyCertSign             (5),
>            cRLSign                 (6),
>            encipherOnly            (7),
>            decipherOnly            (8) }
>
> There are OIDs in the extendedKeyUsage:
>
>     https://datatracker.ietf.org/doc/html/rfc5280#section-4.2.1.12
>
> --
>         Viktor.
>