Issue compiling with openSSL1.1 on Mac:

In file included from ./tls.c:84:
./dh_params.h:33:4: error: incomplete definition of type 'struct dh_st'
        dh->p = BN_bin2bn(dh2048_p, sizeof(dh2048_p), NULL);
        ~~^
/usr/local/opt/openssl@1.1/include/openssl/ossl_typ.h:104:16: note: forward declaration of 'struct dh_st'
typedef struct dh_st DH;
               ^
In file included from ./tls.c:84:
./dh_params.h:34:4: error: incomplete definition of type 'struct dh_st'
        dh->g = BN_bin2bn(dh2048_g, sizeof(dh2048_g), NULL);
        ~~^
/usr/local/opt/openssl@1.1/include/openssl/ossl_typ.h:104:16: note: forward declaration of 'struct dh_st'
typedef struct dh_st DH;
               ^
In file included from ./tls.c:84:
./dh_params.h:35:9: error: incomplete definition of type 'struct dh_st'
        if ((dh->p == NULL) || (dh->g == NULL))
             ~~^
/usr/local/opt/openssl@1.1/include/openssl/ossl_typ.h:104:16: note: forward declaration of 'struct dh_st'
typedef struct dh_st DH;
               ^
In file included from ./tls.c:84:
./dh_params.h:35:28: error: incomplete definition of type 'struct dh_st'
        if ((dh->p == NULL) || (dh->g == NULL))
                                ~~^
/usr/local/opt/openssl@1.1/include/openssl/ossl_typ.h:104:16: note: forward declaration of 'struct dh_st'
typedef struct dh_st DH;


Fixed by updating the dh_params.h to use the getter/setter methods (used DH_set0_pqg instead of dh->p and dh->g):

	if ((dh = DH_new()) == NULL) return(NULL);
	DH_set0_pqg(dh, BN_bin2bn(dh2048_p, sizeof(dh2048_p), NULL), NULL, BN_bin2bn(dh2048_g, sizeof(dh2048_g), NULL));
	if ((DH_get0_p(dh) == NULL) || (DH_get0_g(dh) == NULL))
		{ DH_free(dh); return(NULL); }