pk: align library and tests code to the new internal functions

Note = programs are not aligned to this change because:
- the original mbedtls_pk_ec is not ufficially deprecated
- that function is used in tests when ECP_C is defined, so
  the legacy version of that function is available in that
  case

Signed-off-by: Valerio Setti <valerio.setti@nordicsemi.no>
diff --git a/library/pk.c b/library/pk.c
index 71ab60d..d92de69 100644
--- a/library/pk.c
+++ b/library/pk.c
@@ -879,7 +879,7 @@
         psa_status_t status;
 
         /* export the private key material in the format PSA wants */
-        ec = mbedtls_pk_ec(*pk);
+        ec = mbedtls_pk_ec_rw(*pk);
         d_len = PSA_BITS_TO_BYTES(ec->grp.nbits);
         if ((ret = mbedtls_ecp_write_key(ec, d, d_len)) != 0) {
             return ret;
diff --git a/library/pkparse.c b/library/pkparse.c
index ade8a04..87b707d 100644
--- a/library/pkparse.c
+++ b/library/pkparse.c
@@ -26,6 +26,7 @@
 #include "mbedtls/oid.h"
 #include "mbedtls/platform_util.h"
 #include "mbedtls/error.h"
+#include "pk_internal.h"
 
 #include <string.h>
 
@@ -795,14 +796,14 @@
     if (pk_alg == MBEDTLS_PK_ECKEY_DH || pk_alg == MBEDTLS_PK_ECKEY) {
 #if defined(MBEDTLS_PK_HAVE_RFC8410_CURVES)
         if (mbedtls_pk_is_rfc8410_curve(ec_grp_id)) {
-            ret = pk_use_ecparams_rfc8410(&alg_params, ec_grp_id, &mbedtls_pk_ec(*pk)->grp);
+            ret = pk_use_ecparams_rfc8410(&alg_params, ec_grp_id, &mbedtls_pk_ec_rw(*pk)->grp);
         } else
 #endif
         {
-            ret = pk_use_ecparams(&alg_params, &mbedtls_pk_ec(*pk)->grp);
+            ret = pk_use_ecparams(&alg_params, &mbedtls_pk_ec_rw(*pk)->grp);
         }
         if (ret == 0) {
-            ret = pk_get_ecpubkey(p, end, mbedtls_pk_ec(*pk));
+            ret = pk_get_ecpubkey(p, end, mbedtls_pk_ec_rw(*pk));
         }
     } else
 #endif /* MBEDTLS_ECP_LIGHT */
@@ -1231,10 +1232,10 @@
     if (pk_alg == MBEDTLS_PK_ECKEY || pk_alg == MBEDTLS_PK_ECKEY_DH) {
 #if defined(MBEDTLS_PK_HAVE_RFC8410_CURVES)
         if (mbedtls_pk_is_rfc8410_curve(ec_grp_id)) {
-            if ((ret =
-                     pk_use_ecparams_rfc8410(&params, ec_grp_id, &mbedtls_pk_ec(*pk)->grp)) != 0 ||
+            if ((ret = pk_use_ecparams_rfc8410(&params, ec_grp_id,
+                                               &mbedtls_pk_ec_rw(*pk)->grp)) != 0 ||
                 (ret =
-                     pk_parse_key_rfc8410_der(mbedtls_pk_ec(*pk), p, len, end, f_rng,
+                     pk_parse_key_rfc8410_der(mbedtls_pk_ec_rw(*pk), p, len, end, f_rng,
                                               p_rng)) != 0) {
                 mbedtls_pk_free(pk);
                 return ret;
@@ -1242,8 +1243,8 @@
         } else
 #endif
         {
-            if ((ret = pk_use_ecparams(&params, &mbedtls_pk_ec(*pk)->grp)) != 0 ||
-                (ret = pk_parse_key_sec1_der(mbedtls_pk_ec(*pk), p, len, f_rng, p_rng)) != 0) {
+            if ((ret = pk_use_ecparams(&params, &mbedtls_pk_ec_rw(*pk)->grp)) != 0 ||
+                (ret = pk_parse_key_sec1_der(mbedtls_pk_ec_rw(*pk), p, len, f_rng, p_rng)) != 0) {
                 mbedtls_pk_free(pk);
                 return ret;
             }
@@ -1430,7 +1431,7 @@
         pk_info = mbedtls_pk_info_from_type(MBEDTLS_PK_ECKEY);
 
         if ((ret = mbedtls_pk_setup(pk, pk_info)) != 0 ||
-            (ret = pk_parse_key_sec1_der(mbedtls_pk_ec(*pk),
+            (ret = pk_parse_key_sec1_der(mbedtls_pk_ec_rw(*pk),
                                          pem.buf, pem.buflen,
                                          f_rng, p_rng)) != 0) {
             mbedtls_pk_free(pk);
@@ -1554,7 +1555,7 @@
 #if defined(MBEDTLS_ECP_LIGHT)
     pk_info = mbedtls_pk_info_from_type(MBEDTLS_PK_ECKEY);
     if (mbedtls_pk_setup(pk, pk_info) == 0 &&
-        pk_parse_key_sec1_der(mbedtls_pk_ec(*pk),
+        pk_parse_key_sec1_der(mbedtls_pk_ec_rw(*pk),
                               key, keylen, f_rng, p_rng) == 0) {
         return 0;
     }
diff --git a/library/pkwrite.c b/library/pkwrite.c
index 8872953..1f606a4 100644
--- a/library/pkwrite.c
+++ b/library/pkwrite.c
@@ -26,6 +26,7 @@
 #include "mbedtls/oid.h"
 #include "mbedtls/platform_util.h"
 #include "mbedtls/error.h"
+#include "pk_internal.h"
 
 #include <string.h>
 
@@ -182,7 +183,7 @@
 #endif
 #if defined(MBEDTLS_ECP_LIGHT)
     if (mbedtls_pk_get_type(key) == MBEDTLS_PK_ECKEY) {
-        MBEDTLS_ASN1_CHK_ADD(len, pk_write_ec_pubkey(p, start, mbedtls_pk_ec(*key)));
+        MBEDTLS_ASN1_CHK_ADD(len, pk_write_ec_pubkey(p, start, mbedtls_pk_ec_rw(*key)));
     } else
 #endif
 #if defined(MBEDTLS_USE_PSA_CRYPTO)
@@ -246,7 +247,7 @@
     pk_type = mbedtls_pk_get_type(key);
 #if defined(MBEDTLS_ECP_LIGHT)
     if (pk_type == MBEDTLS_PK_ECKEY) {
-        ec_grp_id = mbedtls_pk_ec(*key)->grp.id;
+        ec_grp_id = mbedtls_pk_ec_ro(*key)->grp.id;
     }
 #endif /* MBEDTLS_ECP_LIGHT */
 #if defined(MBEDTLS_USE_PSA_CRYPTO)
@@ -469,7 +470,7 @@
 #endif /* MBEDTLS_RSA_C */
 #if defined(MBEDTLS_ECP_LIGHT)
     if (mbedtls_pk_get_type(key) == MBEDTLS_PK_ECKEY) {
-        mbedtls_ecp_keypair *ec = mbedtls_pk_ec(*key);
+        mbedtls_ecp_keypair *ec = mbedtls_pk_ec_rw(*key);
         size_t pub_len = 0, par_len = 0;
 
 #if defined(MBEDTLS_PK_HAVE_RFC8410_CURVES)
@@ -591,7 +592,7 @@
 #if defined(MBEDTLS_ECP_LIGHT)
     if (mbedtls_pk_get_type(key) == MBEDTLS_PK_ECKEY) {
 #if defined(MBEDTLS_PK_HAVE_RFC8410_CURVES)
-        if (mbedtls_pk_is_rfc8410_curve(mbedtls_pk_ec(*key)->grp.id)) {
+        if (mbedtls_pk_is_rfc8410_curve(mbedtls_pk_ec_ro(*key)->grp.id)) {
             begin = PEM_BEGIN_PRIVATE_KEY_PKCS8;
             end = PEM_END_PRIVATE_KEY_PKCS8;
         } else
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index cd87164..fe666e8 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -7388,9 +7388,9 @@
             /* and in the unlikely case the above assumption no longer holds
              * we are making sure that pk_ec() here does not return a NULL
              */
-            const mbedtls_ecp_keypair *ec = mbedtls_pk_ec(*pk);
+            const mbedtls_ecp_keypair *ec = mbedtls_pk_ec_ro(*pk);
             if (ec == NULL) {
-                MBEDTLS_SSL_DEBUG_MSG(1, ("mbedtls_pk_ec() returned NULL"));
+                MBEDTLS_SSL_DEBUG_MSG(1, ("mbedtls_pk_ec_ro() returned NULL"));
                 return MBEDTLS_ERR_SSL_INTERNAL_ERROR;
             }
 
diff --git a/library/ssl_tls12_client.c b/library/ssl_tls12_client.c
index d94d829..0940bdb 100644
--- a/library/ssl_tls12_client.c
+++ b/library/ssl_tls12_client.c
@@ -2007,7 +2007,7 @@
         return MBEDTLS_ERR_SSL_PK_TYPE_MISMATCH;
     }
 
-    peer_key = mbedtls_pk_ec(*peer_pk);
+    peer_key = mbedtls_pk_ec_ro(*peer_pk);
 
 #if defined(MBEDTLS_USE_PSA_CRYPTO)
     size_t olen = 0;
diff --git a/library/ssl_tls12_server.c b/library/ssl_tls12_server.c
index ac6c10d..38a3fc4 100644
--- a/library/ssl_tls12_server.c
+++ b/library/ssl_tls12_server.c
@@ -666,7 +666,7 @@
                                uint16_t *curves_tls_id)
 {
     uint16_t *curr_tls_id = curves_tls_id;
-    mbedtls_ecp_group_id grp_id = mbedtls_pk_ec(*pk)->grp.id;
+    mbedtls_ecp_group_id grp_id = mbedtls_pk_ec_ro(*pk)->grp.id;
     mbedtls_ecp_group_id curr_grp_id;
 
     while (*curr_tls_id != 0) {
@@ -2636,7 +2636,7 @@
         case MBEDTLS_PK_ECKEY:
         case MBEDTLS_PK_ECKEY_DH:
         case MBEDTLS_PK_ECDSA:
-            key = mbedtls_pk_ec(*pk);
+            key = mbedtls_pk_ec_ro(*pk);
             if (key == NULL) {
                 return MBEDTLS_ERR_ECP_BAD_INPUT_DATA;
             }
@@ -2704,7 +2704,7 @@
     }
 
     if ((ret = mbedtls_ecdh_get_params(&ssl->handshake->ecdh_ctx,
-                                       mbedtls_pk_ec(*mbedtls_ssl_own_key(ssl)),
+                                       mbedtls_pk_ec_ro(*mbedtls_ssl_own_key(ssl)),
                                        MBEDTLS_ECDH_OURS)) != 0) {
         MBEDTLS_SSL_DEBUG_RET(1, ("mbedtls_ecdh_get_params"), ret);
         return ret;
diff --git a/library/x509_crt.c b/library/x509_crt.c
index 6d62e44..2f6d924 100644
--- a/library/x509_crt.c
+++ b/library/x509_crt.c
@@ -237,7 +237,7 @@
     if (pk_alg == MBEDTLS_PK_ECDSA ||
         pk_alg == MBEDTLS_PK_ECKEY ||
         pk_alg == MBEDTLS_PK_ECKEY_DH) {
-        const mbedtls_ecp_group_id gid = mbedtls_pk_ec(*pk)->grp.id;
+        const mbedtls_ecp_group_id gid = mbedtls_pk_ec_ro(*pk)->grp.id;
 
         if (gid == MBEDTLS_ECP_DP_NONE) {
             return -1;