EVP_get_digestbyname returns null

[axtux]

When I run the software on Ubuntu 18.04, I get this error message:

Cannot initialize the default message digest sha256, aborting

Following the Linux Die manual at https://linux.die.net/man/3/evp_get_digestbyname:

EVP_get_digestbyname(), EVP_get_digestbynid() and EVP_get_digestbyobj() return an EVP_MD structure when passed a digest name, a digest NID or an ASN1_OBJECT structure respectively. The digest table must be initialized using, for example, OpenSSL_add_all_digests() for these functions to work.

Following the instructions from the manual, I added OpenSSL_add_all_digests(); before line 203 in main.c and it works.

I'll open a PR when I have time.

[jarryxy]

Your code needs to add OpenSSL_add_all_digests () in main.c; Otherwise, EVP_get_digestbyname () will return as a NULL pointer. Causes the program to fail to run normally.