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6.2 Certificates ToC Previous Next

6.2.2 Application Instance Certificate ToC Previous Next

An Application Instance Certificate is a ByteString containing the DER encoded form (see X690) of an X.509 v3 Certificate. This Certificate is issued by certifying authority and identifies an instance of an application running on a single host. The X.509 v3 fields contained in an Application Instance Certificate are described in Table 36. The fields are defined completely in RFC 3280.

Table 36 also provides a mapping from the RFC 3280 terms to the terms used in the abstract definition of an Application Instance Certificate defined in OPC 10000-4.

Table 36 – Application Instance Certificate

Name OPC 10000-4 Parameter Name Description
Application Instance Certificate   An X.509 v3 Certificate.
   version    version shall be “V3”
   serialNumber    serialNumber The serial number assigned by the issuer.
   signatureAlgorithm    signatureAlgorithm The algorithm used to sign the Certificate.
   signature    signature The signature created by the Issuer.
   issuer    issuer The distinguished name of the Certificate used to create the signature.
The issuer field is completely described in RFC 3280.
   validity    validTo, validFrom When the Certificate becomes valid and when it expires.
   subject    subject The distinguished name of the application Instance.
The Common Name attribute shall be specified and should be the productName or a suitable equivalent. The Organization Name attribute shall be the name of the Organization that executes the application instance. This organization is usually not the vendor of the application.
Other attributes may be specified.
The subject field is completely described in RFC 3280.
   subjectAltName    applicationUri,
   hostnames
The alternate names for the application Instance.
Shall include a uniformResourceIdentifier which is equal to the applicationUri. The URI shall be a valid URL (see RFC 1738) or a valid URN (see RFC 2141).
Servers   shall specify a partial or a fully qualified dNSName or a static IPAddress which identifies the machine where the application Instance runs. Additional dNSNames may be specified if the machine has multiple names.
The subjectAltName field is completely described in RFC 3280.
   publicKey    publicKey The public key associated with the Certificate.
   keyUsage    keyUsage Specifies how the Certificate key may be used.
Shall include digitalSignature, nonRepudiation, keyEncipherment and dataEncipherment.
Other key uses are allowed.
   extendedKeyUsage    keyUsage Specifies additional key uses for the Certificate.
Shall specify ‘serverAuth and/or clientAuth.
Other key uses are allowed.
   authorityKeyIdentifier    (no mapping) Provides more information about the key used to sign the Certificate. It shall be specified for Certificates signed by a CA. It should be specified for self-signed Certificates.

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