"Host ... returned an invalid certificate" when using gsutil rsync with a s3 bucket that has dots in its name.

Using gsutil rsync with a bucket whose name contains dots causes the following error:

$ gsutil rsync s3://xxxxxx.xxxxxx.xxxxxxxx.xxxxxxxxxxx/ gs://xxxxxxx-xxxxxxx-x/
Building synchronization state...
Caught non-retryable exception while listing s3://xxxxxx.xxxxxx.xxxxxxxx.xxxxxxxxxxx/: Host
xxxxxx.xxxxxx.xxxxxxxx.xxxxxxxxxxx.s3.amazonaws.com returned an invalid certificate (remote
hostname "xxxxxx.xxxxxx.xxxxxxxx.xxxxxxxxxxx.s3.amazonaws.com" does not match certificate):
{
  'notAfter': 'Jun  5 23:59:59 2015 GMT',
  'subjectAltName': (
                      (u'DNS', '*.s3.amazonaws.com'),
                      (u'DNS', 's3.amazonaws.com')
                    ),
  'subject': (
               (('countryName', u'US'),),
               (('stateOrProvinceName', u'Washington'),),
               (('localityName', u'Seattle'),),
               (('organizationName', u'Amazon.com Inc.'),),
               (('organizationalUnitName', u'S3-A'),),
               (('commonName', u'*.s3.amazonaws.com'),)
             )
}

It is possible to circumvent that problem by using https://s3-<region>.amazonaws.com/xxxxxx.xxxxxx.xxxxxxxx.xxxxxxxxxxx as the URL instead; but gsutil does not construct endpoints with that form even in the case of dotted names, causing the error.

[kuzaxak]

Append the next section to ~/.boto file:

[s3] 
calling_format = boto.s3.connection.OrdinaryCallingFormat
host = s3-eu-west-1.amazonaws.com

It will fix the issue. Replace region if you need.

[7heo]

Nope. Never will.