Sample code for 30+ languages & platforms
Unicode C

Duo Auth API - Preauth

See more Duo Auth MFA Examples

The /preauth endpoint determines whether a user is authorized to log in, and (if so) returns the user's available authentication factors.

Chilkat Unicode C Downloads

Unicode C
#include <C_CkHttpW.h>
#include <C_CkHttpRequestW.h>
#include <C_CkHttpResponseW.h>
#include <C_CkJsonObjectW.h>

void ChilkatSample(void)
    {
    BOOL success;
    const wchar_t *integrationKey;
    const wchar_t *secretKey;
    HCkHttpW http;
    const wchar_t *url;
    HCkHttpRequestW req;
    HCkHttpResponseW resp;
    HCkJsonObjectW json;
    const wchar_t *device;
    const wchar_t *display_name;
    const wchar_t *name;
    const wchar_t *number;
    const wchar_t *v_type;
    int j;
    int count_j;
    const wchar_t *strVal;
    const wchar_t *responseResult;
    const wchar_t *responseStatus_msg;
    const wchar_t *stat;
    int i;
    int count_i;

    success = FALSE;

    // This example assumes the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    integrationKey = L"DIMS3V5QDVG9J9ABRXC4";
    secretKey = L"HWVQ46nubLBxhnRlKddTltWIi3hL0fIQF2qTvLab";

    http = CkHttpW_Create();

    CkHttpW_putAccept(http,L"application/json");

    // Use your own hostname here:
    url = L"https://api-a03782e1.duosecurity.com/auth/v2/preauth";

    CkHttpW_putLogin(http,integrationKey);
    CkHttpW_putPassword(http,secretKey);

    req = CkHttpRequestW_Create();
    CkHttpRequestW_AddParam(req,L"username",L"matt");

    CkHttpRequestW_putHttpVerb(req,L"POST");
    CkHttpRequestW_putContentType(req,L"application/x-www-form-urlencoded");

    resp = CkHttpResponseW_Create();
    success = CkHttpW_HttpReq(http,url,req,resp);
    if (success == FALSE) {
        wprintf(L"%s\n",CkHttpW_lastErrorText(http));
        CkHttpW_Dispose(http);
        CkHttpRequestW_Dispose(req);
        CkHttpResponseW_Dispose(resp);
        return;
    }

    wprintf(L"status code = %d\n",CkHttpResponseW_getStatusCode(resp));

    json = CkJsonObjectW_Create();
    success = CkJsonObjectW_Load(json,CkHttpResponseW_bodyStr(resp));
    CkJsonObjectW_putEmitCompact(json,FALSE);
    wprintf(L"%s\n",CkJsonObjectW_emit(json));

    // Sample successful output:

    // status code = 200

    // {
    //   "response": {
    //     "devices": [
    //       {
    //         "capabilities": [
    //           "auto",
    //           "push",
    //           "sms",
    //           "mobile_otp"
    //         ],
    //         "device": "DP6GYVTQ5NK82BMR851F",
    //         "display_name": "iOS (XXX-XXX-1871)",
    //         "name": "",
    //         "number": "XXX-XXX-1871",
    //         "type": "phone"
    //       }
    //     ],
    //     "result": "auth",
    //     "status_msg": "Account is active"
    //   },
    //   "stat": "OK"
    // }

    // Sample code to parse the above JSON response..

    // Use this online tool to generate parsing code from sample JSON: 
    // Generate Parsing Code from JSON

    // Chilkat functions returning "const char *" return a pointer to temporary internal memory owned and managed by Chilkat.
    // See this example explaining how this memory should be used: const char * functions.

    responseResult = CkJsonObjectW_stringOf(json,L"response.result");
    responseStatus_msg = CkJsonObjectW_stringOf(json,L"response.status_msg");
    stat = CkJsonObjectW_stringOf(json,L"stat");
    i = 0;
    count_i = CkJsonObjectW_SizeOfArray(json,L"response.devices");
    while (i < count_i) {
        CkJsonObjectW_putI(json,i);
        device = CkJsonObjectW_stringOf(json,L"response.devices[i].device");
        display_name = CkJsonObjectW_stringOf(json,L"response.devices[i].display_name");
        name = CkJsonObjectW_stringOf(json,L"response.devices[i].name");
        number = CkJsonObjectW_stringOf(json,L"response.devices[i].number");
        v_type = CkJsonObjectW_stringOf(json,L"response.devices[i].type");
        j = 0;
        count_j = CkJsonObjectW_SizeOfArray(json,L"response.devices[i].capabilities");
        while (j < count_j) {
            CkJsonObjectW_putJ(json,j);
            strVal = CkJsonObjectW_stringOf(json,L"response.devices[i].capabilities[j]");
            j = j + 1;
        }

        i = i + 1;
    }



    CkHttpW_Dispose(http);
    CkHttpRequestW_Dispose(req);
    CkHttpResponseW_Dispose(resp);
    CkJsonObjectW_Dispose(json);

    }