(Objective-C) Sign PDF in the Cloud using Azure Key Vault

See more Signing in the Cloud Examples

Demonstrates how to sign a PDF using Azure Key Vault. The signing of the hash happens in the Cloud on Azure Key Vault. Everything else involving the updating the PDF to add the signature happens locally within Chilkat.

Note: This example requires Chilkat v9.5.0.96 or greater.

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#import <CkoPdf.h>
#import <CkoJsonObject.h>
#import <CkoCert.h>

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

CkoPdf *pdf = [[CkoPdf alloc] init];

// Load a PDF to be signed.
BOOL success = [pdf LoadFile: @"qa_data/pdf/helloWorld.pdf"];
if (success == NO) {
    NSLog(@"%@",pdf.LastErrorText);
    return;
}

// Options for signing are specified in JSON.
CkoJsonObject *json = [[CkoJsonObject alloc] init];

// Optionally create an LTV-enabled signature
[json UpdateBool: @"ltvOcsp" value: YES];

// Define the appearance of the signature.
[json UpdateInt: @"page" value: [NSNumber numberWithInt: 1]];
[json UpdateString: @"appearance.y" value: @"top"];
[json UpdateString: @"appearance.x" value: @"left"];
[json UpdateString: @"appearance.fontScale" value: @"10.0"];
[json UpdateString: @"appearance.text[0]" value: @"Digitally signed by: cert_cn"];
[json UpdateString: @"appearance.text[1]" value: @"current_dt"];
[json UpdateString: @"appearance.text[2]" value: @"This is an LTV-enabled signature."];

// Load the certificate used for signing.  The certificate's private key is stored in 
// the Azure Key Vault.
// However, we still need the certificate locally (without private key).
CkoCert *cert = [[CkoCert alloc] init];
success = [cert LoadFromFile: @"qa_data/certs/myCert.cer"];
if (success == NO) {
    NSLog(@"%@",cert.LastErrorText);
    return;
}

// Here's a screenshot of our certificate with private key on Azure Key Vault:


// To sign using the Azure Key Vault, 
// add the following lines of code to specify your authentication credentials,
// and the name of the certificate w/ private key on the Azure server to be used.
CkoJsonObject *jsonAzure = [[CkoJsonObject alloc] init];
// Set the "service" equal to "azure_keyvault" to tell Chilkat to use Azure Key Vault for signing.
[jsonAzure UpdateString: @"service" value: @"azure_keyvault"];
[jsonAzure UpdateString: @"client_id" value: @"APP_ID"];
[jsonAzure UpdateString: @"client_secret" value: @"APP_PASSWORD"];
[jsonAzure UpdateString: @"tenant_id" value: @"TENANT_ID"];
// In the above screenshot, our vault name is "kvchilkat".  You will use your vault name.
[jsonAzure UpdateString: @"vault_name" value: @"VAULT_NAME"];
// In the above screenshot, our cert name is "ChilkatTest1".  You will use your cert name.
[jsonAzure UpdateString: @"cert_name" value: @"CERT_NAME"];
// In the above screenshot, our cert version is "63b94a23389546ecbc8eb6208a1bef37".  You will use your cert version.
[jsonAzure UpdateString: @"cert_version" value: @"CERT_VERSION"];
success = [cert SetCloudSigner: jsonAzure];

// Tell the pdf object to use the certificate for signing (and for Azure Key Vault to do the actual signing of the hash).
success = [pdf SetSigningCert: cert];
if (success == NO) {
    NSLog(@"%@",pdf.LastErrorText);
    return;
}

// Chilkat will build the signed PDF locally, but will (internally) use Azure Key Vault
// to do the RSA (or EC) sign hash operation.
success = [pdf SignPdf: json outFilePath: @"qa_output/hello_ltv_signed.pdf"];
if (success == NO) {
    NSLog(@"%@",pdf.LastErrorText);
    return;
}

NSLog(@"%@",@"PDF Cloud Signing using Azure Key Vault Successful.");