Rename the Elliptic Curves extension to supported_groups

This is a skin deep change, which simply renames most places where we talk
about curves in a TLS context to groups. This is because TLS1.3 has renamed
the extension, and it can now include DH groups too. We still only support
curves, but this rename should pave the way for a future extension for DH
groups.

Reviewed-by: Rich Salz <rsalz@openssl.org>

apps/s_apps.h

diff --git a/apps/s_apps.h b/apps/s_apps.h
index c47932b..4c24b2e 100644
--- a/apps/s_apps.h
+++ b/apps/s_apps.h
@@ -59,7 +59,7 @@
                        STACK_OF(X509) *chain, int build_chain);
 int ssl_print_sigalgs(BIO *out, SSL *s);
 int ssl_print_point_formats(BIO *out, SSL *s);
-int ssl_print_curves(BIO *out, SSL *s, int noshared);
+int ssl_print_groups(BIO *out, SSL *s, int noshared);
 #endif
 int ssl_print_tmp_key(BIO *out, SSL *s);
 int init_client(int *sock, const char *host, const char *port,

apps/s_cb.c

diff --git a/apps/s_cb.c b/apps/s_cb.c
index c37b9a1..d5c308e 100644
--- a/apps/s_cb.c
+++ b/apps/s_cb.c
@@ -307,50 +307,52 @@
     return 1;
 }
 
-int ssl_print_curves(BIO *out, SSL *s, int noshared)
+int ssl_print_groups(BIO *out, SSL *s, int noshared)
 {
-    int i, ncurves, *curves, nid;
-    const char *cname;
+    int i, ngroups, *groups, nid;
+    const char *gname;
 
-    ncurves = SSL_get1_curves(s, NULL);
-    if (ncurves <= 0)
+    ngroups = SSL_get1_groups(s, NULL);
+    if (ngroups <= 0)
         return 1;
-    curves = app_malloc(ncurves * sizeof(int), "curves to print");
-    SSL_get1_curves(s, curves);
+    groups = app_malloc(ngroups * sizeof(int), "groups to print");
+    SSL_get1_groups(s, groups);
 
-    BIO_puts(out, "Supported Elliptic Curves: ");
-    for (i = 0; i < ncurves; i++) {
+    BIO_puts(out, "Supported Elliptic Groups: ");
+    for (i = 0; i < ngroups; i++) {
         if (i)
             BIO_puts(out, ":");
-        nid = curves[i];
+        nid = groups[i];
         /* If unrecognised print out hex version */
         if (nid & TLSEXT_nid_unknown)
             BIO_printf(out, "0x%04X", nid & 0xFFFF);
         else {
+            /* TODO(TLS1.3): Get group name here */
             /* Use NIST name for curve if it exists */
-            cname = EC_curve_nid2nist(nid);
-            if (!cname)
-                cname = OBJ_nid2sn(nid);
-            BIO_printf(out, "%s", cname);
+            gname = EC_curve_nid2nist(nid);
+            if (!gname)
+                gname = OBJ_nid2sn(nid);
+            BIO_printf(out, "%s", gname);
         }
     }
-    OPENSSL_free(curves);
+    OPENSSL_free(groups);
     if (noshared) {
         BIO_puts(out, "\n");
         return 1;
     }
-    BIO_puts(out, "\nShared Elliptic curves: ");
-    ncurves = SSL_get_shared_curve(s, -1);
-    for (i = 0; i < ncurves; i++) {
+    BIO_puts(out, "\nShared Elliptic groups: ");
+    ngroups = SSL_get_shared_group(s, -1);
+    for (i = 0; i < ngroups; i++) {
         if (i)
             BIO_puts(out, ":");
-        nid = SSL_get_shared_curve(s, i);
-        cname = EC_curve_nid2nist(nid);
-        if (!cname)
-            cname = OBJ_nid2sn(nid);
-        BIO_printf(out, "%s", cname);
+        nid = SSL_get_shared_group(s, i);
+        /* TODO(TLS1.3): Convert for DH groups */
+        gname = EC_curve_nid2nist(nid);
+        if (!gname)
+            gname = OBJ_nid2sn(nid);
+        BIO_printf(out, "%s", gname);
     }
-    if (ncurves == 0)
+    if (ngroups == 0)
         BIO_puts(out, "NONE");
     BIO_puts(out, "\n");
     return 1;
@@ -604,7 +606,7 @@
     {"client authz", TLSEXT_TYPE_client_authz},
     {"server authz", TLSEXT_TYPE_server_authz},
     {"cert type", TLSEXT_TYPE_cert_type},
-    {"elliptic curves", TLSEXT_TYPE_elliptic_curves},
+    {"supported_groups", TLSEXT_TYPE_supported_groups},
     {"EC point formats", TLSEXT_TYPE_ec_point_formats},
     {"SRP", TLSEXT_TYPE_srp},
     {"signature algorithms", TLSEXT_TYPE_signature_algorithms},
@@ -1093,7 +1095,7 @@
 #ifndef OPENSSL_NO_EC
     ssl_print_point_formats(bio_err, s);
     if (SSL_is_server(s))
-        ssl_print_curves(bio_err, s, 1);
+        ssl_print_groups(bio_err, s, 1);
     else
         ssl_print_tmp_key(bio_err, s);
 #else

apps/s_server.c

diff --git a/apps/s_server.c b/apps/s_server.c
index 24841c5..9858413 100644
--- a/apps/s_server.c
+++ b/apps/s_server.c
@@ -2560,7 +2560,7 @@
     ssl_print_sigalgs(bio_s_out, con);
 #ifndef OPENSSL_NO_EC
     ssl_print_point_formats(bio_s_out, con);
-    ssl_print_curves(bio_s_out, con, 0);
+    ssl_print_groups(bio_s_out, con, 0);
 #endif
     BIO_printf(bio_s_out, "CIPHER is %s\n", (str != NULL) ? str : "(NONE)");
 
@@ -2847,7 +2847,7 @@
             }
             ssl_print_sigalgs(io, con);
 #ifndef OPENSSL_NO_EC
-            ssl_print_curves(io, con, 0);
+            ssl_print_groups(io, con, 0);
 #endif
             BIO_printf(io, (SSL_session_reused(con)
                             ? "---\nReused, " : "---\nNew, "));