C++ curl connection to vCenter

Question

We are writing a C++ program to integrate to VMware vCenter. We are using the rest API The connection was failing with not found so we have created a separate test program.

We have added a lot of logging and the session seems to be connecting but not accepting the credentials.

Test Code

bool generateSessionID(std::string &sessionID) {
    CURL *curl;
    CURLcode res = CURLE_OK;
    std::string response;

    std::string hostname = "192.168.0.223"; // Hardcoded vCenter IP address
    std::string username = "[email protected]"; // Hardcoded username
    std::string password = "Password1"; // Hardcoded password

    curl = curl_easy_init();
    if (curl) {
        std::string url = "https://" + hostname + "/rest/com/vmware/cis/session";
        curl_easy_setopt(curl, CURLOPT_URL, url.c_str());
        curl_easy_setopt(curl, CURLOPT_USERNAME, username.c_str());
        curl_easy_setopt(curl, CURLOPT_PASSWORD, password.c_str());
        curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, WriteCallback);
        curl_easy_setopt(curl, CURLOPT_WRITEDATA, &response);
        curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0L);
        curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 0L);

        struct curl_slist *headers = NULL;
        headers = curl_slist_append(headers, "Content-Type: application/json");
        curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headers);

        res = curl_easy_perform(curl);
        if (res != CURLE_OK) {
            fprintf(stderr, "curl_easy_perform() failed: %s\n", curl_easy_strerror(res));
        } else {
            long http_code = 0;
            curl_easy_getinfo(curl, CURLINFO_RESPONSE_CODE, &http_code);
            std::cout << "HTTP response code: " << http_code << std::endl;
            std::cout << "Response: " << response << std::endl;

            if (http_code == 200) {
                Json::CharReaderBuilder builder;
                Json::CharReader *reader = builder.newCharReader();
                Json::Value jsonObj;
                std::string errs;

                if (reader->parse(response.c_str(), response.c_str() + response.size(), &jsonObj, &errs)) {
                    sessionID = jsonObj["value"].asString();
                    std::cout << "Session ID: " << sessionID << std::endl;
                } else {
                    std::cerr << "Failed to parse JSON: " << errs << std::endl;
                }

                delete reader;
            } else {
                std::cerr << "Error: HTTP response code " << http_code << std::endl;
            }
        }

        curl_slist_free_all(headers);
        curl_easy_cleanup(curl);
    }

    return res == CURLE_OK;
}

Error

This is the error message we get
HTTP response code: 404
Response:     {"majorErrorCode":404,"name":"com.vmware.vapi.rest.httpNotFound","localizableMessages":[{"args":  [],"defaultMessage":"Not found.","id":"com.vmware.vapi.rest.httpNotFound"}],"type":"com.vmware.vapi.std.errors.not_found","value":{"messages":[{"args":[],"default_message":"Not found.","id":"com.vmware.vapi.rest.httpNotFound"}]}}
Error: HTTP response code 404

We are using the same endpoint in the C++ code as we are when testing from the command line but getting a not found error.

Testing

We have tested the connectivity successfully from the command line using the following

Using httpiw

http --verify=no -a '[email protected]:Password1' POST https://192.168.0.223/rest/com/vmware/cis/session
HTTP/1.1 200 OK
content-type: application/json
date: Fri, 14 Jun 2024 13:20:32 GMT
expires: Thu, 01 Jan 1970 00:00:00 GMT
set-cookie: vmware-api-session-id=3e507a19d9653a97a6b520e9020a9aee; Path=/rest; Secure; HttpOnly, vmware-api-session-id=3e507a19d9653a97a6b520e9020a9aee; Path=/api; Secure; HttpOnly
transfer-encoding: chunked
x-envoy-upstream-service-time: 195

{
    "value": "3e507a19d9653a97a6b520e9020a9aee"
}

Using curl

curl -k -u '[email protected]:Password1' -X POST https://192.168.0.223/rest/com/vmware/cis/session
{"value":"0f9b655ee47584b4493c27c38a99fa55"}

Answer 1

The only difference I can see - libcurl performs GET request, other attempts perform POST requests.

You might want to add

curl_easy_setopt(curl, CURLOPT_POST, 1L);

You can convert the successful curl command example into a C code

curl --libcurl example.c -k -u '[email protected]:Password1' -X POST https://192.168.0.223/rest/com/vmware/cis/session