Gets the {@code issuerUniqueID} value from the certificate.
The issuer unique identifier is present in the certificate
to handle the possibility of reuse of issuer names over time.
RFC 3280 recommends that names not be reused and that
conforming certificates not make use of unique identifiers.
Applications conforming to that profile should be capable of
parsing unique identifiers and making comparisons.
<p>The ASN.1 definition for this is:
<pre>
issuerUniqueID [1] IMPLICIT UniqueIdentifier OPTIONAL
UniqueIdentifier ::= BIT STRING
</pre>
@return the issuer unique identifier or null if it is not
present in the certificate.
Gets the {@code issuerUniqueID} value from the certificate. The issuer unique identifier is present in the certificate to handle the possibility of reuse of issuer names over time. RFC 3280 recommends that names not be reused and that conforming certificates not make use of unique identifiers. Applications conforming to that profile should be capable of parsing unique identifiers and making comparisons.
<p>The ASN.1 definition for this is: <pre> issuerUniqueID [1] IMPLICIT UniqueIdentifier OPTIONAL
UniqueIdentifier ::= BIT STRING </pre>
@return the issuer unique identifier or null if it is not present in the certificate.