Use-After-Free / Dangling Pointer when using session tickets and Open…

[normanmaurer]

…SSL 3.x

Motivation:

On OpenSSL 3.0+, OSSL_PARAM_construct_octet_string stores a raw pointer to the data, not a copy of it and so we need to ensure we make a copy.

Modifications:

• hmac_key is now unconditional (no longer guarded by < 0x30000000L). This gives the struct a stable, heap-allocated 16-byte buffer that lives as long as the ticket_keys array itself. The mac_params array is now only compiled in on OpenSSL 3.0+, but the raw key bytes always live in hmac_key.
• memcpy(ticket_keys[i].hmac_key, ...) now runs unconditionally, copying the 16 bytes out of the JNI array (b) into the struct before b is released.
• mac_params[0] now points to ticket_keys[i].hmac_key — memory owned by the ticket_keys allocation — instead of into b.

Result:

No more use of possible dangling pointer when using OpenSSL 3.x and more consistent code-base