Re: [crypto 6/8] chtls: TCB and Key program

Am Donnerstag, 7. Dezember 2017, 15:21:03 CET schrieb Atul Gupta:

Hi Atul,

memzero_explicit(key)?
[Atul] may not be required as entire info of size keylen and AEAD_H_SIZE is
copied onto kctx->key. Key data is received from user, while ghash is
memset and locally generated

Sure, but wouldn't it make sense to zap all instances where key material was 
stored?

As far as I see, the key is part of the skb (via kctx). This skb is released
after being processed. The release calls kfree_skb which does not zeroize
the key. Wouldn't it make sense to clear the memory of the key when the skb
is released? [Atul] we should perhaps memset the info received from user so
that driver has no info on key once its written on chip memory.
memset(gcm_ctx->key, 0, keylen);

Are you saying that the skb (via kctx) above does not obtain a copy of the 
key? If not, what is done in chtls_key_info?


Ciao
Stephan