Chilkat v10.0.0 is able to create digital signatures for PDF, XmlDSig (XAdES), CAdES, S/MIME, etc. using the HSM (USB token or smartcard) connected to an iPhone. It’s just a matter of calling the certificate object’s LoadFromSmartcard function. You’ll also need to add the “com.apple.token” entitlement to your application.
Here are some examples:
Objective-C Sign PDF using USB Token or Smartcard on iOS iPhone
Swift Sign PDF using USB Token or Smartcard on iOS iPhone
Objective-C Sign XML (XAdES) using USB Token or Smartcard on iOS iPhone
Swift Sign XML (XAdES) using USB Token or Smartcard on iOS iPhone
Objective-C Create CAdES p7m using USB Token or Smartcard on iOS iPhone
Swift Create CAdES p7m using USB Token or Smartcard on iOS iPhone