Slot Description:
Device and Signer compressed certificates are stored in this
slot. This
slot is written with certificate signed by Microchip signers
and root.
It's permanent to support a "factory
reset" option where the original credentials are always
available. It also prevents Denial-Of-Service attacks where
the cert is changed, either intentionally or by accident.
Provisioning:
The slot is provisioned by Microchip based on Customer Root CA
and
Microchip signers.
Customer will be allowed to define some of
the certificate
elements like name and data.
Slot Unused
Custom
Certificate
Custom certificates are currently supported only
for prototype provisioning and not for generating provisioning package.
Notes on Custom Device and Signer
Certificates
Due to the way the certificates
are stored/retrieved from the NextGen-ECC device,
using Custom certificates will require some
knowledge on compressed certificates and certificate
templates.
The issue date only has a resolution of hours.
Minutes and seconds are assumed to be zero.
Refer to Compressed Certificate
Definition for further details on the
compressed certificates.
The custom definition files (.c, .h) being generated
assumes the size of Organization and Common Names
matches with MCHP standard certificates.
The Distinguished Names, both for the Issuer and for
the Subject in all certificates must be comprised of
an Organization Name and a Common Name entry, in
that order.
The Organization Name entered here gets padded and
spaces replaced with '_' to match with MCHP standard
certificates sizes.
It is recommended to use default CommonName i.e.
device serial prefixed with sn. If this needs to be
different, its size would be matched to MCHP
standard certificates with spaces replaced by '_'
For the Device certificate Basic Constraints come
before the Key Usage, following is the order of
extensions:
Basic Constraints: critical, CA:FALSE
Key Usage: critical Digital Signature, Key
Agreement
Subject Key Identifier
Authority Key Identifier
The Subject Common Name in the Signer certificate
resp. the Issuer Common Name in the Device
certificate gets padded and spaces replaced with '_'
to match MCHP standard certificates sizes.
The Signer certificates must contain exactly the
following extensions in exactly the same order:
Key Usage, critical: Digital Signature,
Certificate Sign, CRL Sign
Basic Constraints, critical: CA: TRUE,
PATHLEN: 0
Subject Key Identifier
Authority Key Identifier
Populate below to customize device and signer
certificate fields:
Use default CN
i.e. Serial Number