Hi guys!
I'm trying to upgrade an old C project from OpenSSL 1.0.2 to the newest 1.1.1 version. Everything's going smoothly, except for one little detail:
There's a part of the code where we're doing a sha256 hash of the public key of our certificate. On the older OpenSSL, we were able to get the public key by doing cert->cert_info->key->public_key->data. On the newer version, we no longer have access to the cert_info struct.
I tried doing:
EVP_PKEY * public_key = X509_get0_pubkey(cert);
this gives me an EVP_PKEY value, which I tried to convert to a char** by doing this:
unsigned char *buf, *p;
int len = i2d_PublicKey(public_key, NULL);
buf = OPENSSL_malloc(len);
p = buf;
i2d_PublicKey(public_key, &p);
This gives me a buffer with the correct length, but it seems like it has different data from what the public_key->data used to give me.
Granted, I am not very savvy with OpenSSL, or with ssl in general, so maybe I'm doing something wrong/dumb? I've spent a fair bit of time on the documentation/wiki but I can´t seem to find the answer. Seems to me like this should be something very straightforward?
Any help would be v much appreciated
-Daniel