403 - Forbidden Cannot authenticate user

Question

Not understanding why I am getting this error if I check this URL in Soap UI it is working perfectly. Getting this error after setting body 'Input is not valid JSON at character 1 of '

public static void request(String S,String cd) {
        string customer_code=cd; 
        String SalesOrganization=s;   
        String username ='****';
        String password ='*****';
        string payload='[{"SalesOrganization"  : "solidealusa","customer_code"  : "CS000023"}]';
        Blob headerValue = Blob.valueOf(username+':'+password);
        String authorizationHeader ='BASIC'+EncodingUtil.base64Encode(headerValue);    

        HttpRequest req = new HttpRequest();    
        req.setEndpoint('https://da1.camso.co:50001/RESTAdapter/sold_to/batch');
        req.setMethod('POST');
        req.setHeader('Authorization', authorizationHeader);
        req.setBody(payload);
        req.setCompressed(false); // otherwise we hit a limit of 32000    
      try 
      {
         HttpResponse res = new Http().send(req);     
         system.debug('Response' +res.getBody());          
        } catch(System.CalloutException e) {
        System.debug('Callout error: '+ e);        
        }
     }

Answer 1

Some keywords in web services (SOAP or REST) are case sensitive. For example, Basic, Bearer, Hybrid all should be camel cased (First letter capital and remaining small). Also there should be space between the type of authorization (Basic, Bearer, Hybrid) and the encoded authorization value. So change this

String authorizationHeader ='BASIC'+EncodingUtil.base64Encode(headerValue);

to

String authorizationHeader ='Basic '+EncodingUtil.base64Encode(headerValue);

Hope it helps.