C
C
Get E-way Bill System Access Token
See more HTTP Misc Examples
Sends a request to get an E-way bill system access token.Chilkat C Downloads
#include <C_CkPublicKey.h>
#include <C_CkRsa.h>
#include <C_CkPrng.h>
#include <C_CkJsonObject.h>
#include <C_CkHttp.h>
#include <C_CkHttpResponse.h>
#include <C_CkStringBuilder.h>
#include <C_CkCrypt2.h>
#include <C_CkBinData.h>
#include <C_CkFileAccess.h>
void ChilkatSample(void)
{
BOOL success;
HCkPublicKey pubkey;
const char *password;
HCkRsa rsa;
const char *encPassword;
HCkPrng prng;
const char *app_key;
const char *encAppKey;
HCkJsonObject jsonBody;
HCkHttp http;
HCkHttpResponse resp;
int respStatusCode;
HCkJsonObject json;
int status;
HCkStringBuilder sbError;
const char *authToken;
HCkCrypt2 crypt;
HCkBinData bdSek;
HCkJsonObject jsonEwayAuth;
HCkFileAccess fac;
success = FALSE;
// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.
// First load the public key provided by the E-way bill System
pubkey = CkPublicKey_Create();
success = CkPublicKey_LoadFromFile(pubkey,"qa_data/pem/eway_publickey.pem");
if (success == FALSE) {
printf("%s\n",CkPublicKey_lastErrorText(pubkey));
CkPublicKey_Dispose(pubkey);
return;
}
// Encrypt the password using the RSA public key provided by eway..
password = "my_wepgst_password";
rsa = CkRsa_Create();
CkRsa_putCharset(rsa,"utf-8");
CkRsa_putEncodingMode(rsa,"base64");
success = CkRsa_UsePublicKey(rsa,pubkey);
if (success == FALSE) {
printf("%s\n",CkRsa_lastErrorText(rsa));
CkPublicKey_Dispose(pubkey);
CkRsa_Dispose(rsa);
return;
}
// Returns the encrypted password as base64 (because the EncodingMode = "base64")
encPassword = CkRsa_encryptStringENC(rsa,password,FALSE);
if (CkRsa_getLastMethodSuccess(rsa) == FALSE) {
printf("%s\n",CkRsa_lastErrorText(rsa));
CkPublicKey_Dispose(pubkey);
CkRsa_Dispose(rsa);
return;
}
// Generate a random app_key. This should be 32 bytes (us-ascii chars)
// We need 32 bytes because we'll be doing 256-bit AES ECB encryption, and 32 bytes = 256 bits.
prng = CkPrng_Create();
// Generate a random string containing some numbers, uppercase, and lowercase.
app_key = CkPrng_randomString(prng,32,TRUE,TRUE,TRUE);
printf("app_key = %s\n",app_key);
// RSA encrypt the app_key.
encAppKey = CkRsa_encryptStringENC(rsa,app_key,FALSE);
if (CkRsa_getLastMethodSuccess(rsa) == FALSE) {
printf("%s\n",CkRsa_lastErrorText(rsa));
CkPublicKey_Dispose(pubkey);
CkRsa_Dispose(rsa);
CkPrng_Dispose(prng);
return;
}
// Prepare the JSON body for the HTTP POST that gets the access token.
jsonBody = CkJsonObject_Create();
CkJsonObject_UpdateString(jsonBody,"action","ACCESSTOKEN");
// Use your username instead of "09ABDC24212B1FK".
CkJsonObject_UpdateString(jsonBody,"username","09ABDC24212B1FK");
CkJsonObject_UpdateString(jsonBody,"password",encPassword);
CkJsonObject_UpdateString(jsonBody,"app_key",encAppKey);
http = CkHttp_Create();
// Add required headers.
// Use your ewb-user-id instead of "03AEXPR16A9M010"
CkHttp_SetRequestHeader(http,"ewb-user-id","03AEXPR16A9M010");
// The Gstin should be the same as the username in the jsonBody above.
CkHttp_SetRequestHeader(http,"Gstin","09ABDC24212B1FK");
CkHttp_putAccept(http,"application/json");
// POST the JSON...
resp = CkHttpResponse_Create();
success = CkHttp_HttpJson(http,"POST","http://ewb.wepgst.com/api/Authenticate",jsonBody,"application/json",resp);
if (success == FALSE) {
printf("%s\n",CkHttp_lastErrorText(http));
CkPublicKey_Dispose(pubkey);
CkRsa_Dispose(rsa);
CkPrng_Dispose(prng);
CkJsonObject_Dispose(jsonBody);
CkHttp_Dispose(http);
CkHttpResponse_Dispose(resp);
return;
}
respStatusCode = CkHttpResponse_getStatusCode(resp);
printf("response status code =%d\n",respStatusCode);
printf("response body:\n");
printf("%s\n",CkHttpResponse_bodyStr(resp));
if (respStatusCode != 200) {
printf("Failed in some unknown way.\n");
CkPublicKey_Dispose(pubkey);
CkRsa_Dispose(rsa);
CkPrng_Dispose(prng);
CkJsonObject_Dispose(jsonBody);
CkHttp_Dispose(http);
CkHttpResponse_Dispose(resp);
return;
}
// When the response status code = 200, we'll have either
// success response like this:
// {"status":"1","authtoken":"...","sek":"..."}
//
// or a failed response like this:
//
// {"status":"0","error":"eyJlcnJvckNvZGVzIjoiMTA4In0="}
// Load the response body into a JSON object.
json = CkJsonObject_Create();
CkJsonObject_Load(json,CkHttpResponse_bodyStr(resp));
status = CkJsonObject_IntOf(json,"status");
printf("status = %d\n",status);
if (status != 1) {
// Failed. Base64 decode the error
// {"status":"0","error":"eyJlcnJvckNvZGVzIjoiMTA4In0="}
// For an invalid password, the error is: {"errorCodes":"108"}
sbError = CkStringBuilder_Create();
CkJsonObject_StringOfSb(json,"error",sbError);
CkStringBuilder_Decode(sbError,"base64","utf-8");
printf("error: %s\n",CkStringBuilder_getAsString(sbError));
CkPublicKey_Dispose(pubkey);
CkRsa_Dispose(rsa);
CkPrng_Dispose(prng);
CkJsonObject_Dispose(jsonBody);
CkHttp_Dispose(http);
CkHttpResponse_Dispose(resp);
CkJsonObject_Dispose(json);
CkStringBuilder_Dispose(sbError);
return;
}
// At this point, we know the request was entirely successful.
authToken = CkJsonObject_stringOf(json,"authtoken");
// Decrypt the sek key using our app_key.
crypt = CkCrypt2_Create();
CkCrypt2_putCryptAlgorithm(crypt,"aes");
CkCrypt2_putCipherMode(crypt,"ecb");
CkCrypt2_putKeyLength(crypt,256);
CkCrypt2_SetEncodedKey(crypt,app_key,"us-ascii");
CkCrypt2_putEncodingMode(crypt,"base64");
bdSek = CkBinData_Create();
CkBinData_AppendEncoded(bdSek,CkJsonObject_stringOf(json,"sek"),"base64");
CkCrypt2_DecryptBd(crypt,bdSek);
// bdSek now contains the decrypted symmetric encryption key...
// We'll use it to encrypt the JSON payloads we send.
// Let's persist our authtoken and decrypted sek (symmetric encryption key).
// To send EWAY requests (such as to create an e-way bill), we'll just load
// and use these pre-obtained credentials.
jsonEwayAuth = CkJsonObject_Create();
CkJsonObject_UpdateString(jsonEwayAuth,"authToken",authToken);
CkJsonObject_UpdateString(jsonEwayAuth,"decryptedSek",CkBinData_getEncoded(bdSek,"base64"));
CkJsonObject_putEmitCompact(jsonEwayAuth,FALSE);
fac = CkFileAccess_Create();
CkFileAccess_WriteEntireTextFile(fac,"qa_data/tokens/ewayAuth.json",CkJsonObject_emit(jsonEwayAuth),"utf-8",FALSE);
printf("Saved:\n");
printf("%s\n",CkJsonObject_emit(jsonEwayAuth));
// Sample output:
// {
// "authToken": "IBTeFtxNfVurg71LTzZ2r0xK7",
// "decryptedSek": "5g1TyTie7yoslU3DrbYATa7mWyPazlODE7cEh5Vy4Ho="
//
CkPublicKey_Dispose(pubkey);
CkRsa_Dispose(rsa);
CkPrng_Dispose(prng);
CkJsonObject_Dispose(jsonBody);
CkHttp_Dispose(http);
CkHttpResponse_Dispose(resp);
CkJsonObject_Dispose(json);
CkStringBuilder_Dispose(sbError);
CkCrypt2_Dispose(crypt);
CkBinData_Dispose(bdSek);
CkJsonObject_Dispose(jsonEwayAuth);
CkFileAccess_Dispose(fac);
}