The user can now pass a `free()` function pointer that will be used to
free the memory that has been allocated by the `callback()`.
If `free()` is NULL, the library will still call `XFREE()`.
Signed-off-by: Steffen Jaeckel <s@jaeckel.eu>
The design before was not completely fine. The user had to allocate the
buffer and passed ownership to the library.
As of [0] this seems to be a problem in some environments.
[0] https://github.com/libtom/libtomcrypt/pull/587#issuecomment-1765324724
Signed-off-by: Steffen Jaeckel <s@jaeckel.eu>
* The RFC doesn't limit the context to be a string.
It talks about `octets` which means it could be any binary data.
* Move the context-preprocessing function out of tweetnacl.c
* Fix potential segfaults when Ed25519 signature verification fails and
`LTC_CLEAN_STACK` is enabled.
* Fix all the warnings.
* Update documentation.
Signed-off-by: Steffen Jaeckel <s@jaeckel.eu>
In case when the signature is not verified the "mlen" variable
is equal to ULONG_MAX. When LTC_CLEAN_STACK has been defined
this results in a segmentation fault.
Signed-off-by: Valerii Chubar <valerii_chubar@epam.com>
Signed-off-by: Sergiy Kibrik <Sergiy_Kibrik@epam.com>
