Declare ChaCha-Poly ciphersuites

Prefer them over AES-GCM as they have better performance and fewer side
channel considerations in software implementations.

include/mbedtls/ssl_ciphersuites.h

@@ -271,6 +271,15 @@ extern "C" {
 
 #define MBEDTLS_TLS_ECJPAKE_WITH_AES_128_CCM_8          0xC0FF  /**< experimental */
 
+/* RFC 7905 */
+#define MBEDTLS_TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256   0xCCA8 /**< TLS 1.2 */
+#define MBEDTLS_TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256 0xCCA9 /**< TLS 1.2 */
+#define MBEDTLS_TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256     0xCCAA /**< TLS 1.2 */
+#define MBEDTLS_TLS_PSK_WITH_CHACHA20_POLY1305_SHA256         0xCCAB /**< TLS 1.2 */
+#define MBEDTLS_TLS_ECDHE_PSK_WITH_CHACHA20_POLY1305_SHA256   0xCCAC /**< TLS 1.2 */
+#define MBEDTLS_TLS_DHE_PSK_WITH_CHACHA20_POLY1305_SHA256     0xCCAD /**< TLS 1.2 */
+#define MBEDTLS_TLS_RSA_PSK_WITH_CHACHA20_POLY1305_SHA256     0xCCAE /**< TLS 1.2 */
+
 /* Reminder: update mbedtls_ssl_premaster_secret when adding a new key exchange.
  * Reminder: update MBEDTLS_KEY_EXCHANGE__xxx below
  */

library/ssl_ciphersuites.c

@@ -47,7 +47,7 @@
  * 1. By key exchange:
  *    Forward-secure non-PSK > forward-secure PSK > ECJPAKE > other non-PSK > other PSK
  * 2. By key length and cipher:
- *    AES-256 > Camellia-256 > ARIA-256 > AES-128 > Camellia-128 > ARIA-128 > 3DES
+ *    ChaCha > AES-256 > Camellia-256 > ARIA-256 > AES-128 > Camellia-128 > ARIA-128 > 3DES
  * 3. By cipher mode when relevant GCM > CCM > CBC > CCM_8
  * 4. By hash function used when relevant
  * 5. By key exchange/auth again: EC > non-EC
@@ -57,6 +57,11 @@ static const int ciphersuite_preference[] =
 #if defined(MBEDTLS_SSL_CIPHERSUITES)
     MBEDTLS_SSL_CIPHERSUITES,
 #else
+    /* Chacha-Poly ephemeral suites */
+    MBEDTLS_TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256,
+    MBEDTLS_TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256,
+    MBEDTLS_TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256,
+
     /* All AES-256 ephemeral suites */
     MBEDTLS_TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,
     MBEDTLS_TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,
@@ -127,6 +132,8 @@ static const int ciphersuite_preference[] =
     MBEDTLS_TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA,
 
     /* The PSK ephemeral suites */
+    MBEDTLS_TLS_ECDHE_PSK_WITH_CHACHA20_POLY1305_SHA256,
+    MBEDTLS_TLS_DHE_PSK_WITH_CHACHA20_POLY1305_SHA256,
     MBEDTLS_TLS_DHE_PSK_WITH_AES_256_GCM_SHA384,
     MBEDTLS_TLS_DHE_PSK_WITH_AES_256_CCM,
     MBEDTLS_TLS_ECDHE_PSK_WITH_AES_256_CBC_SHA384,
@@ -227,6 +234,7 @@ static const int ciphersuite_preference[] =
     MBEDTLS_TLS_ECDH_ECDSA_WITH_3DES_EDE_CBC_SHA,
 
     /* The RSA PSK suites */
+    MBEDTLS_TLS_RSA_PSK_WITH_CHACHA20_POLY1305_SHA256,
     MBEDTLS_TLS_RSA_PSK_WITH_AES_256_GCM_SHA384,
     MBEDTLS_TLS_RSA_PSK_WITH_AES_256_CBC_SHA384,
     MBEDTLS_TLS_RSA_PSK_WITH_AES_256_CBC_SHA,
@@ -246,6 +254,7 @@ static const int ciphersuite_preference[] =
     MBEDTLS_TLS_RSA_PSK_WITH_3DES_EDE_CBC_SHA,
 
     /* The PSK suites */
+    MBEDTLS_TLS_PSK_WITH_CHACHA20_POLY1305_SHA256,
     MBEDTLS_TLS_PSK_WITH_AES_256_GCM_SHA384,
     MBEDTLS_TLS_PSK_WITH_AES_256_CCM,
     MBEDTLS_TLS_PSK_WITH_AES_256_CBC_SHA384,
@@ -312,6 +321,75 @@ static const int ciphersuite_preference[] =
 
 static const mbedtls_ssl_ciphersuite_t ciphersuite_definitions[] =
 {
+#if defined(MBEDTLS_CHACHAPOLY_C) && \
+    defined(MBEDTLS_SHA256_C) && \
+    defined(MBEDTLS_SSL_PROTO_TLS1_2)
+#if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED)
+    { MBEDTLS_TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256,
+      "TLS-ECDHE-RSA-WITH-CHACHA20-POLY1305-SHA256",
+      MBEDTLS_CIPHER_CHACHA20_POLY1305, MBEDTLS_MD_SHA256,
+      MBEDTLS_KEY_EXCHANGE_ECDHE_RSA,
+      MBEDTLS_SSL_MAJOR_VERSION_3, MBEDTLS_SSL_MINOR_VERSION_3,
+      MBEDTLS_SSL_MAJOR_VERSION_3, MBEDTLS_SSL_MINOR_VERSION_3,
+      0 },
+#endif
+#if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)
+    { MBEDTLS_TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256,
+      "TLS-ECDHE-ECDSA-WITH-CHACHA20-POLY1305-SHA256",
+      MBEDTLS_CIPHER_CHACHA20_POLY1305, MBEDTLS_MD_SHA256,
+      MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA,
+      MBEDTLS_SSL_MAJOR_VERSION_3, MBEDTLS_SSL_MINOR_VERSION_3,
+      MBEDTLS_SSL_MAJOR_VERSION_3, MBEDTLS_SSL_MINOR_VERSION_3,
+      0 },
+#endif
+#if defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED)
+    { MBEDTLS_TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256,
+      "TLS-DHE-RSA-WITH-CHACHA20-POLY1305-SHA256",
+      MBEDTLS_CIPHER_CHACHA20_POLY1305, MBEDTLS_MD_SHA256,
+      MBEDTLS_KEY_EXCHANGE_DHE_RSA,
+      MBEDTLS_SSL_MAJOR_VERSION_3, MBEDTLS_SSL_MINOR_VERSION_3,
+      MBEDTLS_SSL_MAJOR_VERSION_3, MBEDTLS_SSL_MINOR_VERSION_3,
+      0 },
+#endif
+#if defined(MBEDTLS_KEY_EXCHANGE_PSK_ENABLED)
+    { MBEDTLS_TLS_PSK_WITH_CHACHA20_POLY1305_SHA256,
+      "TLS-PSK-WITH-CHACHA20-POLY1305-SHA256",
+      MBEDTLS_CIPHER_CHACHA20_POLY1305, MBEDTLS_MD_SHA256,
+      MBEDTLS_KEY_EXCHANGE_PSK,
+      MBEDTLS_SSL_MAJOR_VERSION_3, MBEDTLS_SSL_MINOR_VERSION_3,
+      MBEDTLS_SSL_MAJOR_VERSION_3, MBEDTLS_SSL_MINOR_VERSION_3,
+      0 },
+#endif
+#if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED)
+    { MBEDTLS_TLS_ECDHE_PSK_WITH_CHACHA20_POLY1305_SHA256,
+      "TLS-ECDHE-PSK-WITH-CHACHA20-POLY1305-SHA256",
+      MBEDTLS_CIPHER_CHACHA20_POLY1305, MBEDTLS_MD_SHA256,
+      MBEDTLS_KEY_EXCHANGE_ECDHE_PSK,
+      MBEDTLS_SSL_MAJOR_VERSION_3, MBEDTLS_SSL_MINOR_VERSION_3,
+      MBEDTLS_SSL_MAJOR_VERSION_3, MBEDTLS_SSL_MINOR_VERSION_3,
+      0 },
+#endif
+#if defined(MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED)
+    { MBEDTLS_TLS_DHE_PSK_WITH_CHACHA20_POLY1305_SHA256,
+      "TLS-DHE-PSK-WITH-CHACHA20-POLY1305-SHA256",
+      MBEDTLS_CIPHER_CHACHA20_POLY1305, MBEDTLS_MD_SHA256,
+      MBEDTLS_KEY_EXCHANGE_DHE_PSK,
+      MBEDTLS_SSL_MAJOR_VERSION_3, MBEDTLS_SSL_MINOR_VERSION_3,
+      MBEDTLS_SSL_MAJOR_VERSION_3, MBEDTLS_SSL_MINOR_VERSION_3,
+      0 },
+#endif
+#if defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED)
+    { MBEDTLS_TLS_RSA_PSK_WITH_CHACHA20_POLY1305_SHA256,
+      "TLS-RSA-PSK-WITH-CHACHA20-POLY1305-SHA256",
+      MBEDTLS_CIPHER_CHACHA20_POLY1305, MBEDTLS_MD_SHA256,
+      MBEDTLS_KEY_EXCHANGE_RSA_PSK,
+      MBEDTLS_SSL_MAJOR_VERSION_3, MBEDTLS_SSL_MINOR_VERSION_3,
+      MBEDTLS_SSL_MAJOR_VERSION_3, MBEDTLS_SSL_MINOR_VERSION_3,
+      0 },
+#endif
+#endif /* MBEDTLS_CHACHAPOLY_C &&
+          MBEDTLS_SHA256_C &&
+          MBEDTLS_SSL_PROTO_TLS1_2 */
 #if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)
 #if defined(MBEDTLS_AES_C)
 #if defined(MBEDTLS_SHA1_C)

tests/ssl-opt.sh

@@ -723,7 +723,7 @@ run_test    "Default" \
             "$P_CLI" \
             0 \
             -s "Protocol is TLSv1.2" \
-            -s "Ciphersuite is TLS-ECDHE-ECDSA-WITH-AES-256-GCM-SHA384" \
+            -s "Ciphersuite is TLS-ECDHE-RSA-WITH-CHACHA20-POLY1305-SHA256" \
             -s "client hello v3, signature_algorithm ext: 6" \
             -s "ECDHE curve: secp521r1" \
             -S "error" \
@@ -734,20 +734,14 @@ run_test    "Default, DTLS" \
             "$P_CLI dtls=1" \
             0 \
             -s "Protocol is DTLSv1.2" \
-            -s "Ciphersuite is TLS-ECDHE-ECDSA-WITH-AES-256-GCM-SHA384"
+            -s "Ciphersuite is TLS-ECDHE-RSA-WITH-CHACHA20-POLY1305-SHA256"
 
 # Test current time in ServerHello
 requires_config_enabled MBEDTLS_HAVE_TIME
-run_test    "Default, ServerHello contains gmt_unix_time" \
+run_test    "ServerHello contains gmt_unix_time" \
             "$P_SRV debug_level=3" \
             "$P_CLI debug_level=3" \
             0 \
-            -s "Protocol is TLSv1.2" \
-            -s "Ciphersuite is TLS-ECDHE-ECDSA-WITH-AES-256-GCM-SHA384" \
-            -s "client hello v3, signature_algorithm ext: 6" \
-            -s "ECDHE curve: secp521r1" \
-            -S "error" \
-            -C "error" \
             -f "check_server_hello_time" \
             -F "check_server_hello_time"