Merge remote-tracking branch 'upstream-public/pr/1815' into mbedtls-2.1
diff --git a/ChangeLog b/ChangeLog
index 88036e4..3e144a7 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -7,6 +7,9 @@
      MBEDTLS_ARC4_C and MBEDTLS_CIPHER_NULL_CIPHER weren't also defined. #1890
    * Fix a memory leak in ecp_mul_comb() if ecp_precompute_comb() fails.
      Fix contributed by Espressif Systems.
+   * Add ecc extensions only if an ecc based ciphersuite is used.
+     This improves compliance to RFC 4492, and as a result, solves
+     interoperability issues with BouncyCastle. Raised by milenamil in #1157.
 
 = mbed TLS 2.1.14 branch released 2018-07-25
 
diff --git a/library/ssl_cli.c b/library/ssl_cli.c
index 344f248..916a29c 100644
--- a/library/ssl_cli.c
+++ b/library/ssl_cli.c
@@ -678,6 +678,9 @@
     unsigned char offer_compress;
     const int *ciphersuites;
     const mbedtls_ssl_ciphersuite_t *ciphersuite_info;
+#if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C)
+    int uses_ec = 0;
+#endif
 
     MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write client hello" ) );
 
@@ -829,6 +832,10 @@
         MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, add ciphersuite: %2d",
                        ciphersuites[i] ) );
 
+#if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C)
+        uses_ec |= mbedtls_ssl_ciphersuite_uses_ec( ciphersuite_info );
+#endif
+
         n++;
         *p++ = (unsigned char)( ciphersuites[i] >> 8 );
         *p++ = (unsigned char)( ciphersuites[i]      );
@@ -919,11 +926,14 @@
 #endif
 
 #if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C)
-    ssl_write_supported_elliptic_curves_ext( ssl, p + 2 + ext_len, &olen );
-    ext_len += olen;
+    if( uses_ec )
+    {
+        ssl_write_supported_elliptic_curves_ext( ssl, p + 2 + ext_len, &olen );
+        ext_len += olen;
 
-    ssl_write_supported_point_formats_ext( ssl, p + 2 + ext_len, &olen );
-    ext_len += olen;
+        ssl_write_supported_point_formats_ext( ssl, p + 2 + ext_len, &olen );
+        ext_len += olen;
+    }
 #endif
 
 #if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
diff --git a/library/ssl_srv.c b/library/ssl_srv.c
index c04bb53..aea2f3e 100644
--- a/library/ssl_srv.c
+++ b/library/ssl_srv.c
@@ -2448,8 +2448,12 @@
 #endif
 
 #if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C)
-    ssl_write_supported_point_formats_ext( ssl, p + 2 + ext_len, &olen );
-    ext_len += olen;
+    if ( mbedtls_ssl_ciphersuite_uses_ec(
+         mbedtls_ssl_ciphersuite_from_id( ssl->session_negotiate->ciphersuite ) ) )
+    {
+        ssl_write_supported_point_formats_ext( ssl, p + 2 + ext_len, &olen );
+        ext_len += olen;
+    }
 #endif
 
 #if defined(MBEDTLS_SSL_ALPN)
diff --git a/tests/ssl-opt.sh b/tests/ssl-opt.sh
index 3f0ace4..9a432fb 100755
--- a/tests/ssl-opt.sh
+++ b/tests/ssl-opt.sh
@@ -3771,6 +3771,56 @@
             -c "16384 bytes written in 1 fragments" \
             -s "Read from client: 16384 bytes read"
 
+# Tests for ECC extensions (rfc 4492)
+
+requires_config_enabled MBEDTLS_AES_C
+requires_config_enabled MBEDTLS_CIPHER_MODE_CBC
+requires_config_enabled MBEDTLS_SHA256_C
+requires_config_enabled MBEDTLS_KEY_EXCHANGE_RSA_ENABLED
+run_test    "Force a non ECC ciphersuite in the client side" \
+            "$P_SRV debug_level=3" \
+            "$P_CLI debug_level=3 force_ciphersuite=TLS-RSA-WITH-AES-128-CBC-SHA256" \
+            0 \
+            -C "client hello, adding supported_elliptic_curves extension" \
+            -C "client hello, adding supported_point_formats extension" \
+            -S "found supported elliptic curves extension" \
+            -S "found supported point formats extension"
+
+requires_config_enabled MBEDTLS_AES_C
+requires_config_enabled MBEDTLS_CIPHER_MODE_CBC
+requires_config_enabled MBEDTLS_SHA256_C
+requires_config_enabled MBEDTLS_KEY_EXCHANGE_RSA_ENABLED
+run_test    "Force a non ECC ciphersuite in the server side" \
+            "$P_SRV debug_level=3 force_ciphersuite=TLS-RSA-WITH-AES-128-CBC-SHA256" \
+            "$P_CLI debug_level=3" \
+            0 \
+            -C "found supported_point_formats extension" \
+            -S "server hello, supported_point_formats extension"
+
+requires_config_enabled MBEDTLS_AES_C
+requires_config_enabled MBEDTLS_CIPHER_MODE_CBC
+requires_config_enabled MBEDTLS_SHA256_C
+requires_config_enabled MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED
+run_test    "Force an ECC ciphersuite in the client side" \
+            "$P_SRV debug_level=3" \
+            "$P_CLI debug_level=3 force_ciphersuite=TLS-ECDHE-ECDSA-WITH-AES-128-CBC-SHA256" \
+            0 \
+            -c "client hello, adding supported_elliptic_curves extension" \
+            -c "client hello, adding supported_point_formats extension" \
+            -s "found supported elliptic curves extension" \
+            -s "found supported point formats extension"
+
+requires_config_enabled MBEDTLS_AES_C
+requires_config_enabled MBEDTLS_CIPHER_MODE_CBC
+requires_config_enabled MBEDTLS_SHA256_C
+requires_config_enabled MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED
+run_test    "Force an ECC ciphersuite in the server side" \
+            "$P_SRV debug_level=3 force_ciphersuite=TLS-ECDHE-ECDSA-WITH-AES-128-CBC-SHA256" \
+            "$P_CLI debug_level=3" \
+            0 \
+            -c "found supported_point_formats extension" \
+            -s "server hello, supported_point_formats extension"
+
 # Tests for DTLS HelloVerifyRequest
 
 run_test    "DTLS cookie: enabled" \