When you send HTTP requests to AWS, you need to sign the requests so that AWS can identify who sent

them. You sign requests with your AWS access key, which consists of an access key ID and secret access key.

The signing process helps secure requests in the following ways: verify the identity of the requester, protect

data in transit, and protect against potential replay attacks. Creating a signed request includes $3$ steps: $(1)$

create a string to sign for Signature Version $4$; $(2)$ calculate the signature for AWS Signature Version $4$; $(3)$ add

the signature to the HTTP request. AWS Signature Version $4$ is built on HMAC$-$SHA$256$ as shown in Figure $2.$

Suppose that a string to sign is as follows:

AWS$4-$HMAC$-$SHA$256$

$20220320$M$123600$Z

$20220320/$us$-$east$-1/$iam$/$aws$4\_$request

f$536975$d$06$c$0309214$f$805$bb$90$ccff$089219$ecd$68$b$2577$efef$23$edd$43$b$7$e$1$a$59$

Assume that kSecret $=$ your student ID$/$K$7$MDENG$+$bPxRfiCYEXAMPLEKEY.

$(1)$ Compute kDate $=$ HMAC$("$AWS$4"+$ kSecret, Date$),$ where Date $=20220320$;

$(2)$ Compute kRegion $=$ HMAC$($kDate$,$ Region$),$ where Region $=$ us$-$east$-1$;

$(3)$ Compute kService $=$ HMAC$($kRegion$,$ Service$),$ where Service $=$ iam;

$(4)$ Compute kSigning $=$ HMAC$($kService$,$ "aws$4\_$request"$)$;

$(5)$ Compute the signature $=$ HexEncode$($HMAC$($kSigning$,$ string to sign$))$ Student id:S$3720297$