(Delphi DLL) Ibanity HTTP Signature for XS2A, Isabel Connect, Ponto Connect

See more Ibanity Examples

Demonstrates how to add a Signature header for Ibanity HTTP requests.

For more information, see https://documentation.ibanity.com/http-signature

Chilkat for Delphi Downloads Chilkat non-ActiveX DLL for Delphi Chilkat ActiveX DLL for Delphi * The examples here use the non-ActiveX DLL.

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, CkDateTime, Rsa, StringBuilder, JsonObject, PrivateKey, Crypt2;

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Boolean;
json: HCkJsonObject;
payload: PWideChar;
dtNow: HCkDateTime;
created: PWideChar;
crypt: HCkCrypt2;
sbDigestHdrValue: HCkStringBuilder;
request_target: PWideChar;
sbSigningString: HCkStringBuilder;
idempotencyKey: PWideChar;
signed_headers_list: PWideChar;
privKey: HCkPrivateKey;
rsa: HCkRsa;
sigBase64: PWideChar;
sbSigHeaderValue: HCkStringBuilder;

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

// In order to sign your HTTP requests, you have to add 2 headers to the HTTP request: Digest: the digest of the request payload and Signature: the actual signature of the request. 

// POST /xs2a/customer-access-tokens HTTP/1.1
// Host: api.ibanity.com
// Content-Type: application/json
// Digest: SHA-512=z4PhNX7vuL3xVChQ1m2AB9Yg5AULVxXcg/SpIdNs6c5H0NE8XYXysP+DGNKHfuwvY7kxvUdBeoGlODJ6+SfaPg==
// Ibanity-Idempotency-Key: 61f02718-eeee-46e1-b5eb-e8fd6e799c2d
// Signature: keyId="62f02718-eeee-46e1-b5eb-e8fd6e799c2e",created=1599659223,algorithm="hs2019",headers="(request-target) host digest (created) ibanity-idempotency-key",signature="SjWJWbWN7i0...zsbM="
// 
// {"data":{"type":"customerAccessToken", "attributes":{"applicationCustomerReference":"15874569"}}}

// The payload (body) of the above HTTP request is the JSON.
// Build the JSON above.
// Use this online tool to generate code from sample JSON: 
// Generate Code to Create JSON
json := CkJsonObject_Create();
CkJsonObject_UpdateString(json,'data.type','customerAccessToken');
CkJsonObject_UpdateString(json,'data.attributes.applicationCustomerReference','15874569');

payload := CkJsonObject__emit(json);
Memo1.Lines.Add('payload = ' + payload);

// Step 1: Build the (created) virtual header

dtNow := CkDateTime_Create();
CkDateTime_SetFromCurrentSystemTime(dtNow);
created := CkDateTime__getAsUnixTimeStr(dtNow,False);
Memo1.Lines.Add('created = ' + created);

// Step 2: Build the Digest header
crypt := CkCrypt2_Create();
CkCrypt2_putHashAlgorithm(crypt,'sha512');
CkCrypt2_putEncodingMode(crypt,'base64');
CkCrypt2_putCharset(crypt,'utf-8');

sbDigestHdrValue := CkStringBuilder_Create();
CkStringBuilder_Append(sbDigestHdrValue,'SHA-512=');
CkStringBuilder_Append(sbDigestHdrValue,CkCrypt2__hashStringENC(crypt,CkJsonObject__emit(json)));

Memo1.Lines.Add(CkStringBuilder__getAsString(sbDigestHdrValue));

// Step 3: Build the (request target) virtual header

// In order to build the signature you will need a virtual header named (request-target) (the parentheses are important). 
// The (request-target) is the string concatenation of the HTTP method (in lowercase) with the path and query parameters.
request_target := 'post /xs2a/customer-access-tokens';

// Step 4: Build the signing string

// The signing string is the concatenation of the signed header names (in lowercase) and values separated by a LF.

// You must always sign the following headers: (request-target), host, (created), digest. 
// If used, you must also sign the authorization header and any ibanity-* headers, such as ibanity-idempotency-key. 

sbSigningString := CkStringBuilder_Create();
CkStringBuilder_Append(sbSigningString,'(request-target): ');
CkStringBuilder_AppendLine(sbSigningString,request_target,False);
CkStringBuilder_Append(sbSigningString,'host: ');
CkStringBuilder_AppendLine(sbSigningString,'api.ibanity.com',False);
CkStringBuilder_Append(sbSigningString,'digest: ');
CkStringBuilder_AppendLine(sbSigningString,CkStringBuilder__getAsString(sbDigestHdrValue),False);
CkStringBuilder_Append(sbSigningString,'(created): ');
CkStringBuilder_AppendLine(sbSigningString,created,False);
CkStringBuilder_Append(sbSigningString,'ibanity-idempotency-key: ');
idempotencyKey := CkCrypt2__generateUuid(crypt);
CkStringBuilder_Append(sbSigningString,idempotencyKey);

// Step 5: Build the signed headers list

// To allow Ibanity to check the signed headers, you must provide a list of the header names. They should be lowercase and in the same order used to create the signing string. 
signed_headers_list := '(request-target) host digest (created) ibanity-idempotency-key';

// Step 6: Build the Signature header

// This is where the real signing happens. The signature header is a combination of several sub-headers -
// 
//     keyId: the identifier for the application's signature certificate, obtained from the Developer Portal
//     algorithm: the digital signature algorithm used to generate the signature (must be hs2019)
//     headers: The list of HTTP headers created in step 5
//     signature: the Base64-encoded digital signature of the signing string created in step 4.

privKey := CkPrivateKey_Create();
success := CkPrivateKey_LoadEncryptedPemFile(privKey,'my_ibanity_signature_private_key.pem','pem_password');
if (success = False) then
  begin
    Memo1.Lines.Add(CkPrivateKey__lastErrorText(privKey));
    Exit;
  end;

rsa := CkRsa_Create();
CkRsa_putPssSaltLen(rsa,32);
CkRsa_putEncodingMode(rsa,'base64');
// Use the RSASSA-PSS signature algorithm
CkRsa_putOaepPadding(rsa,True);

success := CkRsa_ImportPrivateKeyObj(rsa,privKey);
if (success = False) then
  begin
    Memo1.Lines.Add(CkRsa__lastErrorText(rsa));
    Exit;
  end;

// Sign the signing string.
sigBase64 := CkRsa__signStringENC(rsa,CkStringBuilder__getAsString(sbSigningString),'sha-256');
if (CkRsa_getLastMethodSuccess(rsa) = False) then
  begin
    Memo1.Lines.Add(CkRsa__lastErrorText(rsa));
    Exit;
  end;

// Build the signature header value.
sbSigHeaderValue := CkStringBuilder_Create();
CkStringBuilder_Append(sbSigHeaderValue,'keyId="');
// Use your identifier for the application's signature certificate, obtained from the Developer Portal
CkStringBuilder_Append(sbSigHeaderValue,'62f02718-eeee-46e1-b5eb-e8fd6e799c2e');
CkStringBuilder_Append(sbSigHeaderValue,'",created=');
CkStringBuilder_Append(sbSigHeaderValue,created);
CkStringBuilder_Append(sbSigHeaderValue,',algorithm="hs2019",headers="');
CkStringBuilder_Append(sbSigHeaderValue,signed_headers_list);
CkStringBuilder_Append(sbSigHeaderValue,'",signature="');
CkStringBuilder_Append(sbSigHeaderValue,sigBase64);
CkStringBuilder_Append(sbSigHeaderValue,'"');

Memo1.Lines.Add(CkStringBuilder__getAsString(sbSigHeaderValue));

CkJsonObject_Dispose(json);
CkDateTime_Dispose(dtNow);
CkCrypt2_Dispose(crypt);
CkStringBuilder_Dispose(sbDigestHdrValue);
CkStringBuilder_Dispose(sbSigningString);
CkPrivateKey_Dispose(privKey);
CkRsa_Dispose(rsa);
CkStringBuilder_Dispose(sbSigHeaderValue);

end;