Linux API for PIV smartcards

For interacting with PIV smartcards on a Linux system, there are several APIs and tools available. Here's an overview of some common options: 

1. PKCS#11: - Standard cryptographic token interface - Used by many applications for smartcard operations - Libraries like OpenSC provide PKCS#11 drivers for PIV cards 

2. PC/SC (Personal Computer/Smart Card): - Low-level API for communicating with smartcard readers - Implemented by pcsc-lite on Linux 

3. OpenSC: - Open-source library for smartcard operations - Provides tools and APIs for PIV card management 

4. OpenSSL: - Can be configured to use PKCS#11 for smartcard operations - Useful for certificate operations and key management 

5. GnuPG: - Supports smartcard operations for encryption and signing - Can be used with PIV cards through appropriate card drivers 

6. PKCS#15: - Standard for cryptographic token information format - Often used in conjunction with PKCS#11 

7. libp11: - PKCS#11 wrapper library - Simplifies integration of PKCS#11 modules with OpenSSL For development, you might use a combination of these, typically starting with PC/SC for reader communication, and then using PKCS#11 or OpenSC for higher-level card operations.