Benchmark only one side of ECDH, both static and ephemeral

Static ECDH is of interest to us as developers because it's a generic
scalar multiplication (as opposed to using the standard base point) and
it's useful to have that handy.

For reference the other operations of interest to developers are:
- multiplication of the conventional base point: ECDSA signing is almost
exactly that (just a few field ops on top, notably 1 inversion);
- linear combination: ECDSA verification is almost exactly that too.

Including ephemeral as well, because it's hopefully what's of interest
to most users.

Compared to the previous version, include only one side of the
operations. I don't think including both sides is of interest to anyone.

Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>

1 files changed, 42 insertions, 15 deletions

diff --git a/programs/test/benchmark.c b/programs/test/benchmark.c
index 0861d0f..93c1729 100644
--- a/programs/test/benchmark.c
+++ b/programs/test/benchmark.c
@@ -1191,7 +1191,7 @@ int main(int argc, char *argv[])
         mbedtls_ecdh_context ecdh_srv, ecdh_cli;
         unsigned char buf_srv[BUFSIZE], buf_cli[BUFSIZE];
         const mbedtls_ecp_curve_info *curve_info;
-        size_t olen;
+        size_t params_len, publen, seclen;
 
         for (curve_info = curve_list;
              curve_info->grp_id != MBEDTLS_ECP_DP_NONE;
@@ -1201,33 +1201,60 @@ int main(int argc, char *argv[])
             }
 
             mbedtls_ecdh_init(&ecdh_srv);
-            mbedtls_ecdh_init(&ecdh_cli);
+
+            CHECK_AND_CONTINUE(mbedtls_ecdh_setup(&ecdh_srv, curve_info->grp_id));
+            CHECK_AND_CONTINUE(mbedtls_ecdh_make_params(&ecdh_srv, &params_len, buf_srv,
+                                                        sizeof(buf_srv), myrand, NULL));
 
             mbedtls_snprintf(title, sizeof(title), "ECDHE-%s", curve_info->name);
             TIME_PUBLIC(title,
-                        "full handshake",
+                        "ephemeral handshake",
                         const unsigned char *p_srv = buf_srv;
-
-                        CHECK_AND_CONTINUE(mbedtls_ecdh_setup(&ecdh_srv, curve_info->grp_id));
-                        CHECK_AND_CONTINUE(mbedtls_ecdh_make_params(&ecdh_srv, &olen, buf_srv,
-                                                                    sizeof(buf_srv), myrand, NULL));
+                        mbedtls_ecdh_init(&ecdh_cli);
 
                         CHECK_AND_CONTINUE(mbedtls_ecdh_read_params(&ecdh_cli, &p_srv,
-                                                                    p_srv + olen));
-                        CHECK_AND_CONTINUE(mbedtls_ecdh_make_public(&ecdh_cli, &olen, buf_cli,
+                                                                    p_srv + params_len));
+                        CHECK_AND_CONTINUE(mbedtls_ecdh_make_public(&ecdh_cli, &publen, buf_cli,
                                                                     sizeof(buf_cli), myrand, NULL));
 
-                        CHECK_AND_CONTINUE(mbedtls_ecdh_read_public(&ecdh_srv, buf_cli, olen));
-                        CHECK_AND_CONTINUE(mbedtls_ecdh_calc_secret(&ecdh_srv, &olen, buf_srv,
-                                                                    sizeof(buf_srv), myrand, NULL));
-
-                        CHECK_AND_CONTINUE(mbedtls_ecdh_calc_secret(&ecdh_cli, &olen, buf_cli,
+                        CHECK_AND_CONTINUE(mbedtls_ecdh_calc_secret(&ecdh_cli, &seclen, buf_cli,
                                                                     sizeof(buf_cli), myrand, NULL));
                         mbedtls_ecdh_free(&ecdh_cli);
+                        );
 
-                        mbedtls_ecdh_free(&ecdh_srv);
+            mbedtls_ecdh_free(&ecdh_srv);
+        }
+
+        for (curve_info = curve_list;
+             curve_info->grp_id != MBEDTLS_ECP_DP_NONE;
+             curve_info++) {
+            if (!mbedtls_ecdh_can_do(curve_info->grp_id)) {
+                continue;
+            }
+
+            mbedtls_ecdh_init(&ecdh_srv);
+            mbedtls_ecdh_init(&ecdh_cli);
+
+            CHECK_AND_CONTINUE(mbedtls_ecdh_setup(&ecdh_srv, curve_info->grp_id));
+            CHECK_AND_CONTINUE(mbedtls_ecdh_make_params(&ecdh_srv, &params_len, buf_srv,
+                                                        sizeof(buf_srv), myrand, NULL));
+
+            const unsigned char *p_srv = buf_srv;
+            CHECK_AND_CONTINUE(mbedtls_ecdh_read_params(&ecdh_cli, &p_srv,
+                                                        p_srv + params_len));
+            CHECK_AND_CONTINUE(mbedtls_ecdh_make_public(&ecdh_cli, &publen, buf_cli,
+                                                        sizeof(buf_cli), myrand, NULL));
+
+
+            mbedtls_snprintf(title, sizeof(title), "ECDH-%s", curve_info->name);
+            TIME_PUBLIC(title,
+                        "static handshake",
+                        CHECK_AND_CONTINUE(mbedtls_ecdh_calc_secret(&ecdh_cli, &seclen, buf_cli,
+                                                                    sizeof(buf_cli), myrand, NULL));
                         );
 
+            mbedtls_ecdh_free(&ecdh_cli);
+            mbedtls_ecdh_free(&ecdh_srv);
         }
     }
 #endif