curl

➜ curl https://savannah.gnu.org/bugs/index.php\?20421
curl: (60) SSL certificate problem, verify that the CA cert is OK. Details:
error:14090086:SSL routines:SSL3_GET_SERVER_CERTIFICATE:certificate verify failed
More details here: http://curl.haxx.se/docs/sslcerts.html

curl performs SSL certificate verification by default, using a "bundle"
 of Certificate Authority (CA) public keys (CA certs). If the default
 bundle file isn't adequate, you can specify an alternate file
 using the --cacert option.
If this HTTPS server uses a certificate signed by a CA represented in
 the bundle, the certificate verification probably failed due to a
 problem with the certificate (it might be expired, or the name might
 not match the domain name in the URL).
If you'd like to turn off curl's verification of the certificate, use
 the -k (or --insecure) option.
➜ curl https://github.com/atmos/cinderella -o document.html
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100 35135  100 35135    0     0  32190      0  0:00:01  0:00:01 --:--:-- 84256

wget

➜ wget https://github.com/atmos/cinderella
--2010-12-15 05:44:54--  https://github.com/atmos/cinderella
Resolving github.com... 207.97.227.239
Connecting to github.com|207.97.227.239|:443... connected.
ERROR: certificate common name `*.github.com' doesn't match requested host name `github.com'.
To connect to github.com insecurely, use `--no-check-certificate'.
➜ wget https://savannah.gnu.org/bugs/index.php\?20421
--2010-12-15 05:45:11--  https://savannah.gnu.org/bugs/index.php?20421
Resolving savannah.gnu.org... 140.186.70.70
Connecting to savannah.gnu.org|140.186.70.70|:443... connected.
ERROR: cannot verify savannah.gnu.org's certificate, issued by `/O=Root CA/OU=http://www.cacert.org/CN=CA Cert Signing Authority/[email protected]':
  Unable to locally verify the issuer's authority.
To connect to savannah.gnu.org insecurely, use `--no-check-certificate'.