$11.$ What is the packet number in your trace for the TLS message part that contains the public key certificate for the www$.$cics.umass.edu server $($actually the www$.$cs$.$umass.edu server$)?$

$12.$ A server may return more than one certificate. If more than one certificate is returned, are all of these certificates for www$.$cs$.$umass.edu? If not all are for www$.$cs$.$umass.edu, then who are these other certificates for? You can determine who the certificate is for by checking the id$-$at$-$commonName field in the retuned certificate.

$13.$ What is the name of the certification authority that issued the certificate for id$-$at$-$commonName$=$www$.$cs$.$umass.edu?

$14.$ What digital signature algorithm is used by the CA to sign this certificate? Hint: this information can be found in signature subfield of the SignedCertificate field of the certificate for www$.$cs$.$umass.edu.

$15.$ Let's take a look at what a real public key looks like! What are the first four hexadecimal digits of the modulus of the public key being used by www$.$cics.umass.edu? Enter the four hexadecimal digits $($without spaces between the hex digits and without any leading $\text{'}0$x$\text{'},$ using lowercase letters where needed, and including any leading $0$s after $\text{'}0$x$\text{'}).$ Hint: this information can be found in subjectPublicKeyInfo subfield of the SignedCertificate field of the certificate for www$.$cs$.$umass.edu.

$16.$ Look in your trace to find messages between the client and a CA to get the CA$$s public key information, so that the client can verify that the CA$-$signed certificate sent by the server is indeed valid and has not been forged or altered. Do you see such message in your trace? If so$,$ what is the number in the trace of the first packet sent from your client to the CA$?$ If not, explain why the client did not contact the CA$.$