如何使用OpenSSL提取公钥？

#include <openssl/bn.h>
#include <openssl/err.h>
#include <openssl/evp.h>
#include <openssl/asn1.h>
#include <openssl/asn1t.h>
#include <openssl/pem.h>

const char *public_key_data = "-----BEGIN PUBLIC KEY-----\
MIGfMA0GCSqGSIb3DQEJARYQAlice@example.com+AEEwDQYJKoZIhvc...
-----END PUBLIC KEY-----\
";

EVP_PKEY *public_key = EVP_PKEY_new_raw_public_key(EVP_PKEY_RSA, NULL);
EVP_PKEY_assign_RSA(public_key, EVP_PKEY_get0_RSA(public_key_data));
char *public_key_bn = BN_bn2hex(EVP_PKEY_get0_RSA(public_key_data));

printf("Public key:
");
for (int i = 0; i < EVP_PKEY_size(public_key); i++) {
    printf("%02x", EVP_PKEY_get0_RSA(public_key_data)[i]);
}
printf("
");