How do I make an HTTP Post with HTTP Basic Authentication, using POCO?

Question

I'm trying to make an HTTP Post with HTTP Basic Authentication (cleartext username and password), using POCO. I found an example of a Get and have tried to modify it, but being a rookie I think I've mangled it beyond usefulness. Anyone know how to do this?

Yes, I've already seen the other SO question on this: POCO C++ - NET SSL - how to POST HTTPS request, but I can't make sense of how it is trying to implement the username and password part. I also don't understand the use of "x-www-form-urlencoded". Is this required for a Post? I don't have a form. Just want to POST to the server with username and password parameters.

Answer 1

Finally. Here's how you do it:

    HTTPClientSession session("yourdomain.com");
    session.setKeepAlive(true);

    Poco::Net::HTTPRequest req(Poco::Net::HTTPRequest::HTTP_POST, "/myapi.php/api/validate", HTTPMessage::HTTP_1_1);
    req.setContentType("application/x-www-form-urlencoded");
    req.setKeepAlive(true); // notice setKeepAlive is also called on session (above)

    std::string reqBody("username=user1@yourdomain.com&password=mypword");
    req.setContentLength( reqBody.length() );

    std::ostream& myOStream = session.sendRequest(req); // sends request, returns open stream
    myOStream << reqBody;  // sends the body

    req.write(std::cout);

    Poco::Net::HTTPResponse res;
    std::istream& iStr = session.receiveResponse(res);  // get the response from server
    std::cerr << iStr.rdbuf();  // dump server response so you can view it

Answer 2

When you do an HTTP POST, typically the data that is being sent to the server is sent in one of two forms:

• Name,Value pairs where the name and value are separated by "=", and distinct pairs are separated by "&". For example: var1=value1&var2=value2. Also, these name value pairs are sent so that certain special characters and non-alphanumeric characters are replaced by %HH, a percent sign and two hexadecimal digits representing the ASCII code of the character. For example, if value for the first parameter included an "#", it would be sent as var1=value1%23&var2=value2. When sending data in this format, the client is required to insert a Content-Type header with the value application/x-www-form-urlencoded so that the server may be able to decode the data correctly.

• As a multipart MIME body where each part can be large in size as well as include "non-escaped" data (including binary data). Different MIME parts are separated by a string delimiter (boundary) that does not appear within any of the MIME "payloads". When sending data in this format, the client is required to insert a Content-Type header with the value multipart/form-data.

In the case of the previous StackOverflow question you referenced, the request body is being sent in the first manner as shown above. Hope that clarifies.

Regards, Siddharth

Answer 3

From the POCO library credential test, here is the code:

HTTPRequest request;
assert (!request.hasCredentials());

HTTPBasicCredentials cred("user", "secret");
cred.authenticate(request);
assert (request.hasCredentials());
std::string scheme;
std::string info;
request.getCredentials(scheme, info);
assert (scheme == "Basic");
assert (info == "dXNlcjpzZWNyZXQ=");

HTTPBasicCredentials cred2(request);
assert (cred2.getUsername() == "user");
assert (cred2.getPassword() == "secret");

When sending the request, you would only use the first part of this code (stopping at cred.authenticate(request)).