External Signing Services on Android

PSPDFKit supports external signature providers such as hardware security modules (HSMs) and other signing entities. The SignatureProvider interface defines classes capable of signing PDF blob data, which is required as part of the digital signing process of a PDF.

The default implementation used by PSPDFKit, aka the PrivateKeySignatureProvider, signs PDF data using a java.security.KeyStore.PrivateKeyEntry. Both Pkcs12Signer and MemorySigner derive from PrivateKeySignatureProvider and can be used if your app stores the private key of a user directly on the device. If you’re using an external signing service (such as an HSM), implement a custom Signer as shown in CustomSignatureProviderExample.