For example, running wget https://www.dropbox.com
results in the following errors:
ERROR: The certificate of `www.dropbox.com' is not trusted.
ERROR: The certificate of `www.dropbox.com' hasn't got a known issuer.
If you don't care about checking the validity of the certificate just add the --no-check-certificate
option on the wget command-line. This worked well for me.
NOTE: This opens you up to man-in-the-middle (MitM) attacks, and is not recommended for anything where you care about security.