timestamping: update key usage for ts cert

[asraa]

Signed-off-by: Asra Ali asraa@google.com

Summary

• Updates key usage per Implement RFC 3161 timestamp responses #293 (comment)

Ticket Link

Fixes

Release Note

Confirmed openssl still like it

asraa@asraa-glaptop:~/git/rekor$ ./rekor timestamp --artifact README.md --rekor_server http://localhost:3000
Artifact timestamped at 2021-11-22 15:19:39 +0000 UTC
Wrote timestamp response to response.tsr
Created entry at index 0, available at: http://localhost:3000/api/v1/log/entries/fc4398aef624a8d32f876e32b03e31f132fdb29584492aed05b7dde539807f4b
asraa@asraa-glaptop:~/git/rekor$ curl http://localhost:3000/api/v1/timestamp/certchain --output -
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----
-----BEGIN CERTIFICATE-----
MIIBdzCCARygAwIBAgICB+MwCgYIKoZIzj0EAwIwIjEgMB4GA1UEChMXcmVrb3Ig
aW4tbWVtb3J5IHJvb3QgQ0EwHhcNMjExMTIyMTUxNzQ1WhcNMzExMTIyMTUxNzQ1
WjAiMSAwHgYDVQQKExdyZWtvciBpbi1tZW1vcnkgcm9vdCBDQTBZMBMGByqGSM49
AgEGCCqGSM49AwEHA0IABDJUQex+ECYA3tQdamAlUotYZiKsZjSVTd6fuEAx6div
DUKAKVFOolLrbhKkhkB7dD86se816LRGADKe+lU7yqKjQjBAMA4GA1UdDwEB/wQE
AwICxDAPBgNVHRMBAf8EBTADAQH/MB0GA1UdDgQWBBQEvI6a3bcvS9iWZ/STjIa9
kRF8lzAKBggqhkjOPQQDAgNJADBGAiEA/+X65oP1S97BRBz4SKGL452Vd1Yi593+
KJo4n6ok/4ACIQDfDa0j6IwbzBmwfNU1wLNRv26EqIWvjsbxpbRtqTwRsw==
-----END CERTIFICATE-----
asraa@asraa-glaptop:~/git/rekor$ emacs ts.cert
asraa@asraa-glaptop:~/git/rekor$ emacs root.ca
asraa@asraa-glaptop:~/git/rekor$ openssl ts -verify -in response.tsr -data README.md -CAfile root.ca -untrusted ts.cert
Using configuration from /usr/lib/ssl/openssl.cnf
Verification: OK

[asraa]

cc @mstjohns