make EVP_PKEY opaque

Reviewed-by: Richard Levitte <levitte@openssl.org>
diff --git a/ssl/t1_lib.c b/ssl/t1_lib.c
index 41b55c8..6937b45 100644
--- a/ssl/t1_lib.c
+++ b/ssl/t1_lib.c
@@ -793,9 +793,9 @@
     if (!pkey)
         return 0;
     /* If not EC nothing to do */
-    if (pkey->type != EVP_PKEY_EC)
+    if (EVP_PKEY_id(pkey) != EVP_PKEY_EC)
         return 1;
-    rv = tls1_set_ec_id(curve_id, &comp_id, pkey->pkey.ec);
+    rv = tls1_set_ec_id(curve_id, &comp_id, EVP_PKEY_get0_EC_KEY(pkey));
     if (!rv)
         return 0;
     /*
@@ -990,10 +990,10 @@
         return 0;
     }
 #ifndef OPENSSL_NO_EC
-    if (pkey->type == EVP_PKEY_EC) {
+    if (EVP_PKEY_id(pkey) == EVP_PKEY_EC) {
         unsigned char curve_id[2], comp_id;
         /* Check compression and curve matches extensions */
-        if (!tls1_set_ec_id(curve_id, &comp_id, pkey->pkey.ec))
+        if (!tls1_set_ec_id(curve_id, &comp_id, EVP_PKEY_get0_EC_KEY(pkey)))
             return 0;
         if (!s->server && !tls1_check_ec_key(s, curve_id, &comp_id)) {
             SSLerr(SSL_F_TLS12_CHECK_PEER_SIGALG, SSL_R_WRONG_CURVE);
@@ -3227,7 +3227,7 @@
 
 int tls12_get_sigid(const EVP_PKEY *pk)
 {
-    return tls12_find_id(pk->type, tls12_sig, OSSL_NELEM(tls12_sig));
+    return tls12_find_id(EVP_PKEY_id(pk), tls12_sig, OSSL_NELEM(tls12_sig));
 }
 
 typedef struct {
@@ -4110,7 +4110,7 @@
     if (!s->server && strict_mode) {
         STACK_OF(X509_NAME) *ca_dn;
         int check_type = 0;
-        switch (pk->type) {
+        switch (EVP_PKEY_id(pk)) {
         case EVP_PKEY_RSA:
             check_type = TLS_CT_RSA_SIGN;
             break;