def METHOD_NAME(self):
    self.mkfs()
    passphrase_new = 'sd982jhd'
    proc = subprocess.Popen(
        self.s3ql_cmd_argv('s3qladm')
        + [
            '--quiet',
            '--log',
            'none',
            '--authfile',
            '/dev/null',
            'passphrase',
            self.storage_url,
        ],
        stdin=subprocess.PIPE,
        universal_newlines=True,
    )
    print(self.passphrase, file=proc.stdin)
    print(passphrase_new, file=proc.stdin)
    print(passphrase_new, file=proc.stdin)
    proc.stdin.close()
    self.assertEqual(proc.wait(), 0)
    plain_backend = local.Backend(Namespace(storage_url=self.storage_url))
    backend = ComprencBackend(passphrase_new.encode(), ('zlib', 6), plain_backend)
    backend.fetch('s3ql_passphrase')  # will fail with wrong pw