Revert "Only support >= 256-bit elliptic curves with ecdh_auto (server) or by default (client)."

PeterMosmans · PeterMosmans · commit f340dabc8591 · 2016-05-24T09:10:14.000+10:00
This reverts commit f4d1fb7.
diff --git a/CHANGES b/CHANGES
@@ -433,11 +433,6 @@
      (CVE-2015-1791)
      [Matt Caswell]
 
-  *) Only support 256-bit or stronger elliptic curves with the
-     'ecdh_auto' setting (server) or by default (client). Of supported
-     curves, prefer P-256 (both).
-     [Emilia Kasper]
-
   *) Reject DH handshakes with parameters shorter than 768 bits.
      [Kurt Roeckx and Emilia Kasper]
 
diff --git a/ssl/ssltest.c b/ssl/ssltest.c
@@ -1456,9 +1456,12 @@ int main(int argc, char *argv[])
                 BIO_printf(bio_err, "unknown curve name (%s)\n", named_curve);
                 goto end;
             }
-        } else {
+        } else
+# ifdef OPENSSL_NO_EC2M
             nid = NID_X9_62_prime256v1;
-        }
+# else
+            nid = NID_sect163r2;
+# endif
 
         ecdh = EC_KEY_new_by_curve_name(nid);
         if (ecdh == NULL) {
diff --git a/ssl/t1_lib.c b/ssl/t1_lib.c
@@ -262,68 +262,47 @@ static const unsigned char ecformats_default[] = {
     TLSEXT_ECPOINTFORMAT_ansiX962_compressed_char2
 };
 
-/* The client's default curves / the server's 'auto' curves. */
-static const unsigned char eccurves_auto[] = {
-    /* Prefer P-256 which has the fastest and most secure implementations. */
-    0, 23,                      /* secp256r1 (23) */
-    /* Other >= 256-bit prime curves. */
-    0, 25,                      /* secp521r1 (25) */
-    0, 28,                      /* brainpool512r1 (28) */
-    0, 27,                      /* brainpoolP384r1 (27) */
-    0, 24,                      /* secp384r1 (24) */
-    0, 26,                      /* brainpoolP256r1 (26) */
-    0, 22,                      /* secp256k1 (22) */
+static const unsigned char eccurves_default[] = {
 # ifndef OPENSSL_NO_EC2M
-    /* >= 256-bit binary curves. */
     0, 14,                      /* sect571r1 (14) */
     0, 13,                      /* sect571k1 (13) */
-    0, 11,                      /* sect409k1 (11) */
-    0, 12,                      /* sect409r1 (12) */
-    0, 9,                       /* sect283k1 (9) */
-    0, 10,                      /* sect283r1 (10) */
 # endif
-};
-
-static const unsigned char eccurves_all[] = {
-    /* Prefer P-256 which has the fastest and most secure implementations. */
-    0, 23,                      /* secp256r1 (23) */
-    /* Other >= 256-bit prime curves. */
     0, 25,                      /* secp521r1 (25) */
     0, 28,                      /* brainpool512r1 (28) */
-    0, 27,                      /* brainpoolP384r1 (27) */
-    0, 24,                      /* secp384r1 (24) */
-    0, 26,                      /* brainpoolP256r1 (26) */
-    0, 22,                      /* secp256k1 (22) */
 # ifndef OPENSSL_NO_EC2M
-    /* >= 256-bit binary curves. */
-    0, 14,                      /* sect571r1 (14) */
-    0, 13,                      /* sect571k1 (13) */
     0, 11,                      /* sect409k1 (11) */
     0, 12,                      /* sect409r1 (12) */
+# endif
+    0, 27,                      /* brainpoolP384r1 (27) */
+    0, 24,                      /* secp384r1 (24) */
+# ifndef OPENSSL_NO_EC2M
     0, 9,                       /* sect283k1 (9) */
     0, 10,                      /* sect283r1 (10) */
 # endif
-    /*
-     * Remaining curves disabled by default but still permitted if set
-     * via an explicit callback or parameters.
-     */
-    0, 20,                      /* secp224k1 (20) */
-    0, 21,                      /* secp224r1 (21) */
-    0, 18,                      /* secp192k1 (18) */
-    0, 19,                      /* secp192r1 (19) */
-    0, 15,                      /* secp160k1 (15) */
-    0, 16,                      /* secp160r1 (16) */
-    0, 17,                      /* secp160r2 (17) */
+    0, 26,                      /* brainpoolP256r1 (26) */
+    0, 22,                      /* secp256k1 (22) */
+    0, 23,                      /* secp256r1 (23) */
 # ifndef OPENSSL_NO_EC2M
     0, 8,                       /* sect239k1 (8) */
     0, 6,                       /* sect233k1 (6) */
     0, 7,                       /* sect233r1 (7) */
+# endif
+    0, 20,                      /* secp224k1 (20) */
+    0, 21,                      /* secp224r1 (21) */
+# ifndef OPENSSL_NO_EC2M
     0, 4,                       /* sect193r1 (4) */
     0, 5,                       /* sect193r2 (5) */
+# endif
+    0, 18,                      /* secp192k1 (18) */
+    0, 19,                      /* secp192r1 (19) */
+# ifndef OPENSSL_NO_EC2M
     0, 1,                       /* sect163k1 (1) */
     0, 2,                       /* sect163r1 (2) */
     0, 3,                       /* sect163r2 (3) */
 # endif
+    0, 15,                      /* secp160k1 (15) */
+    0, 16,                      /* secp160r1 (16) */
+    0, 17,                      /* secp160r2 (17) */
 };
 
 static const unsigned char suiteb_curves[] = {
@@ -497,13 +476,8 @@ static int tls1_get_curvelist(SSL *s, int sess,
             } else
 # endif
             {
-                if (!s->server || s->cert->ecdh_tmp_auto) {
-                    *pcurves = eccurves_auto;
-                    pcurveslen = sizeof(eccurves_auto);
-                } else {
-                    *pcurves = eccurves_all;
-                    pcurveslen = sizeof(eccurves_all);
-                }
+                *pcurves = eccurves_default;
+                pcurveslen = sizeof(eccurves_default);
             }
         }
     }
