Segmentation fault using AES GCM and SoftHSMv2

[jonasholtkamp]

We're trying to use this proxy (thanks for the work!) together with SoftHSMv2 and Graphene to encrypt using AES GCM. We started by patching the following files to allow for AES GCM support:

• added CKM_AES_GCM: in gck-rpc-util.c
• added #define CKM_AES_GCM (0x1087UL) in pkcs11/pkcs11.h

However, that yields a segfault in libsofthsm2.so at this spot. Probably it's the access of CK_GCM_PARAMS_PTR(pMechanism->pParameter)->pIv that's failing here.

Judging from the implementation we're calling C_EncryptInit with the following mechanism parameters:

{ 
  iv: <Buffer 31 32 33 34 35 36 37 38 39 30 31 32>, // that's 123456789012 in UTF-8
  ivBits: 128,
  ivLen: 12,
  aad: <Buffer >,
  aadLen: 0,
  tagBits: 128,
}

Can you/somebody give any advice or help on how we can fix or at least debug this issue?