Pkcs11-provider: side-channel proofing pkcs#1 1.5 paths

A security vulnerability has been identified in the pkcs11-provider, which is associated with Public-Key Cryptography Standards (PKCS#11). If exploited successfully, this vulnerability could result in a Bleichenbacher-like security flaw, potentially enabling a side-channel attack on PKCS#1 1.5 decryption.