Which expression confirms that all client certificates presented to the authentication vServer remain valid until the year 2023?

• A. CLIENT.SSL.CLIENT_CERT.VALID_NOT_AFTER.EQ(GMT2023)
• B. CLIENT.SSL.CLIENT_CERT.VALID_NOT_BEFORE.EQ(GMT2023)
• C. CLIENT.SSL.ORIGIN_SERVER_CERT.VALID_NOT_AFTER.EQ(GMT2023)
• D. CLIENT.SSL.CLIENT_CERT.DAYS_TO_EXPIRE.EQ(2023)

Answer: (A)

The expression uses the client certificate's expiration date. VALID_NOT_AFTER represents when the client certificate ceases to be valid. By comparing it to GMT2023, you’re checking that the certificate’s not-after date falls in the year 2023, meaning the client certificates presented will be valid up through 2023. The other options don’t target the client certificate’s expiry year: VALID_NOT_BEFORE would test when the certificate becomes valid, not when it expires; the origin server cert check looks at a different certificate (the server’s), not the client’s; and DAYS_TO_EXPIRE is a numeric value that wouldn’t directly represent a year. Therefore the correct choice confirms expiry in 2023 by checking VALID_NOT_AFTER against GMT2023.