Hello.

Im having difficulty creating test method for the reCaptcha.

The verify() function is trigerred when Save() is called, please see bellow:
 

public PageReference save(){
       verify();
        If (verified==true){
        ....
        }

The reCapture methods perse are as follows:
 

@TestVisible private String baseUrl = 'https://www.google.com/recaptcha/api/siteverify?';
@TestVisible private String privateKey = 'MyPrivateKey';
@TestVisible public String publicKey {get { return 'MypublicKey'; }}
@TestVisible public String challenge { get {returnApexPages.currentPage().getParameters().get('recaptcha challenge');}}
@TestVisible public String response  { get {returnApexPages.currentPage().getParameters().get('g-recaptcha-response');}}
    public Boolean verified { get; set; }
    
    public void verify() {HttpResponse r = makeRequest(baseUrl, 'secret=' + privateKey +'&response='  + response +'&remoteip='  + remoteHost );
                          System.debug(r.getBody());
                          JSONParser parser = JSON.createParser(r.getBody());
                          while (parser.nextToken() != null) {
                             if ((parser.getCurrentToken() == JSONToken.FIELD_NAME) && (parser.getText() == 'success')) {
                                  parser.nextToken();
                                  if (parser.getBooleanValue()==true){verified =true;}else{verified = false;} }
                          }
                         }
    public PageReference reset() {return null; }
    @TestVisible private HttpResponse makeRequest(string url, string body)  {
        HttpResponse response = null;
        HttpRequest req = new HttpRequest();  
        req.setEndpoint(url);
        req.setMethod('POST');
        req.setBody (body);
        try {
            Http http = new Http();
            response = http.send(req);
            System.debug('reCAPTCHA response: ' + response);
            System.debug('reCAPTCHA body: ' + response.getBody());
        } catch(System.Exception e) {
            System.debug('ERROR: ' + e);
        }
        return response;
    }  
     
    @TestVisible public String remoteHost {get {
        String ret = '127.0.0.1';
        Map<String, String> hdrs = ApexPages.currentPage().getHeaders();
        if (hdrs.get('REMOTE_ADDR')!= null)
          ret =  hdrs.get('x-original-remote-addr');
        else if (hdrs.get('X-Salesforce-SIP')!= null)
           ret =  hdrs.get('X-Salesforce-SIP');
        return ret;
    }
   }

As per suggestions on forums, particularly the resource: 
https://developer.salesforce.com/index.php?title=Adding_CAPTCHA_to_Force.com_Sites&oldid=42318
i came up to the following insertion into a test method for the function save():
 

ctr= new controllerLeadConfirmationPage();
...
string href = ctr.baseUrl ;
ctr.response = 'foo';
ctr.challenge = ctr.response;
string publick = ctr.publicKey;
string host = ctr.remoteHost;
...
ctr.save()

But still I cannot get it working:
System.NullPointerException: Attempt to de-reference a null object - line 1191 (which is  ' System.debug(r.getBody());' in the verify() function bellow)
 

public void verify() {HttpResponse r = makeRequest(baseUrl, 'secret=' + privateKey +'&response='  + response +'&remoteip='  + remoteHost );
                          System.debug(r.getBody());
                          JSONParser parser = JSON.createParser(r.getBody());
                          while (parser.nextToken() != null) {
                              if ((parser.getCurrentToken() == JSONToken.FIELD_NAME) && (parser.getText() == 'success')) {
                                  parser.nextToken();
                                  if (parser.getBooleanValue()==true){verified =true;}else{verified = false;} }
                          }
                         }

Please advise me how can i solve it.