Java Requires Chilkat v11.0.0+

Get E-way Bill System Access Token

See more HTTP Misc Examples

Sends a request to get an E-way bill system access token. Chilkat2 Java

import com.chilkatsoft.chilkat2.BinData;
import com.chilkatsoft.chilkat2.ChilkatException;
import com.chilkatsoft.chilkat2.Crypt2;
import com.chilkatsoft.chilkat2.FileAccess;
import com.chilkatsoft.chilkat2.Http;
import com.chilkatsoft.chilkat2.HttpResponse;
import com.chilkatsoft.chilkat2.JsonObject;
import com.chilkatsoft.chilkat2.Prng;
import com.chilkatsoft.chilkat2.PublicKey;
import com.chilkatsoft.chilkat2.Rsa;
import com.chilkatsoft.chilkat2.StringBuilder;

public class ChilkatExample {

    public static void main(String[] args) {
        // 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
        PublicKey pubkey = new PublicKey();
        try {
            pubkey.loadFromFile("qa_data/pem/eway_publickey.pem");
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // Encrypt the password using the RSA public key provided by eway..
        String password = "my_wepgst_password";
        Rsa rsa = new Rsa();
        rsa.setCharset("utf-8");
        rsa.setEncodingMode("base64");

        String encPassword;
        try {
            rsa.usePublicKey(pubkey);

            // Returns the encrypted password as base64 (because the EncodingMode = "base64")
            encPassword = rsa.encryptStringENC(password, false);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            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 prng = new Prng();
        // Generate a random string containing some numbers, uppercase, and lowercase.
        String app_key = prng.randomString(32, true, true, true);

        System.out.println("app_key = " + app_key);

        // RSA encrypt the app_key.
        String encAppKey;
        try {
            encAppKey = rsa.encryptStringENC(app_key, false);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // Prepare the JSON body for the HTTP POST that gets the access token.
        JsonObject jsonBody = new JsonObject();
        jsonBody.updateString("action", "ACCESSTOKEN");
        // Use your username instead of "09ABDC24212B1FK".
        jsonBody.updateString("username", "09ABDC24212B1FK");
        jsonBody.updateString("password", encPassword);
        jsonBody.updateString("app_key", encAppKey);

        Http http = new Http();

        // Add required headers.
        // Use your ewb-user-id instead of "03AEXPR16A9M010"
        http.setRequestHeader("ewb-user-id", "03AEXPR16A9M010");
        // The Gstin should be the same as the username in the jsonBody above.
        http.setRequestHeader("Gstin", "09ABDC24212B1FK");
        http.setAccept("application/json");

        // POST the JSON...
        HttpResponse resp = new HttpResponse();
        try {
            http.httpJson("POST", "http://ewb.wepgst.com/api/Authenticate", jsonBody, "application/json", resp);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        int respStatusCode = resp.getStatusCode();
        System.out.println("response status code =" + respStatusCode);
        System.out.println("response body:");
        System.out.println(resp.getBodyStr());

        if (respStatusCode != 200) {
            System.out.println("Failed in some unknown way.");
            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.
        JsonObject json = new JsonObject();
        json.load(resp.getBodyStr());

        int status = json.intOf("status");
        System.out.println("status = " + status);

        if (status != 1) {
            // Failed.  Base64 decode the error
            // {"status":"0","error":"eyJlcnJvckNvZGVzIjoiMTA4In0="}
            // For an invalid password, the error is: {"errorCodes":"108"}
            StringBuilder sbError = new StringBuilder();
            json.stringOfSb("error", sbError);
            sbError.decode("base64", "utf-8");
            System.out.println("error: " + sbError.getAsString());
            return;
        }

        // At this point, we know the request was entirely successful.
        String authToken = json.stringOf("authtoken");

        // Decrypt the sek key using our app_key.
        Crypt2 crypt = new Crypt2();
        crypt.setCryptAlgorithm("aes");
        crypt.setCipherMode("ecb");
        crypt.setKeyLength(256);
        crypt.setEncodedKey(app_key, "us-ascii");
        crypt.setEncodingMode("base64");

        BinData bdSek = new BinData();
        bdSek.appendEncoded(json.stringOf("sek"), "base64");
        crypt.decryptBd(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.
        JsonObject jsonEwayAuth = new JsonObject();
        jsonEwayAuth.updateString("authToken", authToken);
        jsonEwayAuth.updateString("decryptedSek", bdSek.getEncoded("base64"));
        jsonEwayAuth.setEmitCompact(false);

        FileAccess fac = new FileAccess();
        fac.writeEntireTextFile("qa_data/tokens/ewayAuth.json", jsonEwayAuth.emit(), "utf-8", false);

        System.out.println("Saved:");
        System.out.println(jsonEwayAuth.emit());

        // Sample output:
        // {
        //   "authToken": "IBTeFtxNfVurg71LTzZ2r0xK7",
        //   "decryptedSek": "5g1TyTie7yoslU3DrbYATa7mWyPazlODE7cEh5Vy4Ho="
        // }
    }
}