Lazarus Pascal Requires Chilkat v11.0.0+
Lazarus Pascal
ING Open Banking OAuth2 Client Credentials
See more OAuth2 Examples
Demonstrates how to get an access token for the ING Open Banking APIs using client credentials.Chilkat Lazarus Pascal Downloads
program ChilkatDemo;
// Demonstrates using the Chilkat Pascal wrapper via the C bridge DLL.
// Builds as a console application under Lazarus (FPC) or Delphi.
{$IFDEF FPC}
{$MODE DELPHI}
{$ENDIF}
{$APPTYPE CONSOLE}
uses
{$IFDEF UNIX}
cthreads,
{$ENDIF}
SysUtils,
CkDllLoader,
Chilkat.CkDateTime,
Chilkat.Rsa,
Chilkat.HttpResponse,
Chilkat.JsonObject,
Chilkat.Http,
Chilkat.BinData,
Chilkat.PrivateKey,
Chilkat.StringBuilder,
Chilkat.Cert,
Chilkat.Crypt2,
Chilkat.HttpRequest;
// ---------------------------------------------------------------------------
procedure RunDemo;
var
success: Boolean;
cert: TCert;
bdPrivKey: TBinData;
privKey: TPrivateKey;
http: THttp;
crypt: TCrypt2;
payload: string;
payloadDigest: string;
dt: TCkDateTime;
httpMethod: string;
reqPath: string;
sbStringToSign: TStringBuilder;
signingPrivKey: TPrivateKey;
rsa: TRsa;
b64Signature: string;
sbAuthHdrVal: TStringBuilder;
sbDigestHdrVal: TStringBuilder;
req: THttpRequest;
resp: THttpResponse;
json: TJsonObject;
kty: string;
n: string;
e: string;
use: string;
alg: string;
x5t: string;
access_token: string;
expires_in: Integer;
scope: string;
token_type: string;
client_id: string;
i: Integer;
count_i: Integer;
begin
success := False;
// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.
cert := TCert.Create;
success := cert.LoadFromFile('qa_data/certs_and_keys/ING/example_client_tls.cer');
if (success = False) then
begin
WriteLn(cert.LastErrorText);
Exit;
end;
bdPrivKey := TBinData.Create;
success := bdPrivKey.LoadFile('qa_data/certs_and_keys/ING/example_client_tls.key');
if (success = False) then
begin
WriteLn('Failed to load example_client_tls.key');
Exit;
end;
// The OAuth 2.0 client_id for these certificates is e77d776b-90af-4684-bebc-521e5b2614dd.
// Please note down this client_id since you will need it in the next steps to call the API.
privKey := TPrivateKey.Create;
success := privKey.LoadAnyFormat(bdPrivKey,'');
if (success = False) then
begin
WriteLn(privKey.LastErrorText);
Exit;
end;
// Associate the private key with the certificate.
success := cert.SetPrivateKey(privKey);
if (success = False) then
begin
WriteLn(cert.LastErrorText);
Exit;
end;
http := THttp.Create;
success := http.SetSslClientCert(cert);
if (success = False) then
begin
WriteLn(http.LastErrorText);
Exit;
end;
// Calculate the Digest and add the "Digest" header. Do the equivalent of this:
// payload="grant_type=client_credentials"
// payloadDigest=`echo -n "$payload" | openssl dgst -binary -sha256 | openssl base64`
// digest=SHA-256=$payloadDigest
crypt := TCrypt2.Create;
crypt.HashAlgorithm := 'SHA256';
crypt.EncodingMode := 'base64';
payload := 'grant_type=client_credentials';
payloadDigest := crypt.HashStringENC(payload);
// Calculate the current date/time and add the Date header.
// reqDate=$(LC_TIME=en_US.UTF-8 date -u "+%a, %d %b %Y %H:%M:%S GMT")
dt := TCkDateTime.Create;
dt.SetFromCurrentSystemTime();
// The desire date/time format is the "RFC822" format.
http.SetRequestHeader('Date',dt.GetAsRfc822(False));
// Calculate signature for signing your request
// Duplicate the following code:
// httpMethod="post"
// reqPath="/oauth2/token"
// signingString="(request-target): $httpMethod $reqPath
// date: $reqDate
// digest: $digest"
// signature=`printf "$signingString" | openssl dgst -sha256 -sign "${certPath}example_client_signing.key" -passin "pass:changeit" | openssl base64 -A`
httpMethod := 'POST';
reqPath := '/oauth2/token';
sbStringToSign := TStringBuilder.Create;
sbStringToSign.Append('(request-target): ');
sbStringToSign.Append(httpMethod);
sbStringToSign.ToLowercase();
sbStringToSign.Append(' ');
sbStringToSign.AppendLine(reqPath,False);
sbStringToSign.Append('date: ');
sbStringToSign.AppendLine(dt.GetAsRfc822(False),False);
sbStringToSign.Append('digest: SHA-256=');
sbStringToSign.Append(payloadDigest);
signingPrivKey := TPrivateKey.Create;
success := signingPrivKey.LoadPemFile('qa_data/certs_and_keys/ING/example_client_signing.key');
if (success = False) then
begin
WriteLn(signingPrivKey.LastErrorText);
Exit;
end;
rsa := TRsa.Create;
success := rsa.UsePrivateKey(signingPrivKey);
if (success = False) then
begin
WriteLn(rsa.LastErrorText);
Exit;
end;
rsa.EncodingMode := 'base64';
b64Signature := rsa.SignStringENC(sbStringToSign.GetAsString(),'SHA256');
sbAuthHdrVal := TStringBuilder.Create;
sbAuthHdrVal.Append('Signature keyId="e77d776b-90af-4684-bebc-521e5b2614dd",');
sbAuthHdrVal.Append('algorithm="rsa-sha256",');
sbAuthHdrVal.Append('headers="(request-target) date digest",');
sbAuthHdrVal.Append('signature="');
sbAuthHdrVal.Append(b64Signature);
sbAuthHdrVal.Append('"');
sbDigestHdrVal := TStringBuilder.Create;
sbDigestHdrVal.Append('SHA-256=');
sbDigestHdrVal.Append(payloadDigest);
// Do the following CURL statement:
// curl -i -X POST "${httpHost}${reqPath}" \
// -H 'Accept: application/json' \
// -H 'Content-Type: application/x-www-form-urlencoded' \
// -H "Digest: ${digest}" \
// -H "Date: ${reqDate}" \
// -H "authorization: Signature keyId=\"$keyId\",algorithm=\"rsa-sha256\",headers=\"(request-target) date digest\",signature=\"$signature\"" \
// -d "${payload}" \
// --cert "${certPath}tlsCert.crt" \
// --key "${certPath}tlsCert.key"
req := THttpRequest.Create;
req.AddParam('grant_type','client_credentials');
req.AddHeader('Accept','application/json');
req.AddHeader('Date',dt.GetAsRfc822(False));
req.AddHeader('Digest',sbDigestHdrVal.GetAsString());
req.AddHeader('Authorization',sbAuthHdrVal.GetAsString());
req.HttpVerb := 'POST';
req.ContentType := 'application/x-www-form-urlencoded';
resp := THttpResponse.Create;
success := http.HttpReq('https://api.sandbox.ing.com/oauth2/token',req,resp);
if (success = False) then
begin
WriteLn(http.LastErrorText);
Exit;
end;
// If successful, the status code = 200
WriteLn('Response Status Code: ' + resp.StatusCode);
WriteLn(resp.BodyStr);
json := TJsonObject.Create;
json.Load(resp.BodyStr);
json.EmitCompact := False;
WriteLn(json.Emit());
// A successful response contains an access token such as:
// {
// "access_token": "eyJhbGc ... bxI_SoPOBH9xmoM",
// "expires_in": 905,
// "scope": "payment-requests:view payment-requests:create payment-requests:close greetings:view virtual-ledger-accounts:fund-reservation:create virtual-ledger-accounts:fund-reservation:delete virtual-ledger-accounts:balance:view",
// "token_type": "Bearer",
// "keys": [
// {
// "kty": "RSA",
// "n": "3l3rdz4...04VPkdV",
// "e": "AQAB",
// "use": "sig",
// "alg": "RS256",
// "x5t": "3c396700fc8cd709cf9cb5452a22bcde76985851"
// }
// ],
// "client_id": "e77d776b-90af-4684-bebc-521e5b2614dd"
// }
// Use this online tool to generate parsing code from sample JSON:
// Generate Parsing Code from JSON
access_token := json.StringOf('access_token');
expires_in := json.IntOf('expires_in');
scope := json.StringOf('scope');
token_type := json.StringOf('token_type');
client_id := json.StringOf('client_id');
i := 0;
count_i := json.SizeOfArray('keys');
while i < count_i do
begin
json.I := i;
kty := json.StringOf('keys[i].kty');
n := json.StringOf('keys[i].n');
e := json.StringOf('keys[i].e');
use := json.StringOf('keys[i].use');
alg := json.StringOf('keys[i].alg');
x5t := json.StringOf('keys[i].x5t');
i := i + 1;
end;
// This example will save the JSON containing the access key to a file so that
// a subsequent example can load it and then use the access key for a request, such as to create a payment request.
json.WriteFile('qa_data/tokens/ing_access_token.json');
cert.Free;
bdPrivKey.Free;
privKey.Free;
http.Free;
crypt.Free;
dt.Free;
sbStringToSign.Free;
signingPrivKey.Free;
rsa.Free;
sbAuthHdrVal.Free;
sbDigestHdrVal.Free;
req.Free;
resp.Free;
json.Free;
end;
// ---------------------------------------------------------------------------
begin
try
RunDemo;
except
on E: Exception do
WriteLn('Unhandled exception: ', E.ClassName, ': ', E.Message);
end;
WriteLn;
{$IFDEF MSWINDOWS}
WriteLn('Press Enter to exit...');
ReadLn;
{$ENDIF}
end.