Gets the {@code notBefore} date from the validity period of the certificate. The relevant ASN.1 definitions are: <pre> validity Validity
Validity ::= SEQUENCE { notBefore CertificateValidityDate, notAfter CertificateValidityDate }
CertificateValidityDate ::= CHOICE { utcTime UTCTime, generalTime GeneralizedTime } </pre>
@return the start date of the validity period. @see #checkValidity
See Implementation
Gets the {@code notBefore} date from the validity period of the certificate. The relevant ASN.1 definitions are: <pre> validity Validity
Validity ::= SEQUENCE { notBefore CertificateValidityDate, notAfter CertificateValidityDate }
CertificateValidityDate ::= CHOICE { utcTime UTCTime, generalTime GeneralizedTime } </pre>
@return the start date of the validity period. @see #checkValidity