java.lang.IllegalArgumentException: Illegal character(s) in message header value: Basic someLongBase64EncodedMessHereEtcEtcEtcEtcEtcEtcEtcEtcEtcEtcEtcEtcEtcAndAnEOL

	sun.net.www.protocol.http.HttpURLConnection.checkMessageHeader(HttpURLConnection.java:428)
	sun.net.www.protocol.http.HttpURLConnection.isExternalMessageHeaderAllowed(HttpURLConnection.java:394)
	sun.net.www.protocol.http.HttpURLConnection.setRequestProperty(HttpURLConnection.java:2374)
	sun.net.www.protocol.https.HttpsURLConnectionImpl.setRequestProperty(HttpsURLConnectionImpl.java:296)
	com.saucelabs.rest.Credential.call(Credential.java:167)
	com.saucelabs.rest.Credential.call(Credential.java:151)
	com.saucelabs.rest.SauceTunnelFactory.list(SauceTunnelFactory.java:88)
	hudson.plugins.sauce_ondemand.PluginImpl$DescriptorImpl.doValidate(PluginImpl.java:137)

String userpassword = username + ":" + key;
con.setRequestProperty("Authorization", "Basic " + new BASE64Encoder().encode(userpassword.getBytes()));

public class Demo {
    public static void main(String... args) {
        System.out.println("got: '" + new sun.misc.BASE64Encoder().encode(new String("someusername:apiKeyEtc01234567890123456789012345678901234").getBytes()) + "'");
    }
}

got: 'c29tZXVzZXJuYW1lOmFwaUtleUV0YzAxMjM0NTY3ODkwMTIzNDU2Nzg5MDEyMzQ1Njc4OTAxMjM0
'

public class Demo {
    public static void main(String... args) {
        System.out.println("got: '" + new sun.misc.BASE64Encoder() {
            @Override protected int bytesPerLine() {
                return 9999;
            }
        }.encode(new String("someusername:apiKeyEtc01234567890123456789012345678901234").getBytes()) + "'");
    }
}

got: 'c29tZXVzZXJuYW1lOmFwaUtleUV0YzAxMjM0NTY3ODkwMTIzNDU2Nzg5MDEyMzQ1Njc4OTAxMjM0'