#1 change the way to get keys

[sbernard]

I will talk about the PSK issue but there are the same issue for ECC.

Currently, to pass the key from user code to tinyDTLS, we must use the :
get_psk_key from dtls_handler_t.

The current implementation force user to store the key in a static way.
There are 2 problems for me with this :

1. I'm working on a Lua Binding on tinyDTLS (luadtls), I would like to pass the key from lua to C. Currently I must create a static structure in memory to store statically the key in my C code while it is already store in Lua.
2. Key is sensitive data. The time where the unencrypted key is store memory should be as short as possible to limit an attack by memory dump. Here a post which explains the idea.

So a better implementation could be that tinyDTLS allocate memory for the key, then call the get_psk_key which will fill the struct, then with a memset clean the memory.

[Olaf Bergmann]

I completely agree with your concerns and will fix this as suggested.

[Olaf Bergmann]

This is fixed for PSK in commit 046f9d62. To save some overhead, the psk_hint and psk are now retrieved independent from each other. dtls_psk_key_t is now obsolete and has been removed in 1fba423.

For ECC, this is a bit more difficult hence the bug is not yet closed.

[sbernard]

Thx Olaf, I just integrate it now.

(off topic, but could you add ".project" entry to .gitignore as I can open tiny dtls in eclipse CDT)