Enable restart for certificate verify
diff --git a/include/mbedtls/ssl_internal.h b/include/mbedtls/ssl_internal.h
index 00a8db4..4cfe154 100644
--- a/include/mbedtls/ssl_internal.h
+++ b/include/mbedtls/ssl_internal.h
@@ -231,6 +231,8 @@
     mbedtls_x509_crt_restart_ctx ecrs_ctx;  /*!< restart context            */
     enum {
         ssl_ecrs_init = 0,              /*!< just getting started           */
+        ssl_ecrs_crt_parsed,            /*!< server certificate was parsed  */
+        ssl_ecrs_crt_verified,          /*!< server certificate was verified*/
         ssl_ecrs_ske_read,              /*!< ServerKeyExchange was read     */
         ssl_ecrs_ske_verified,          /*!< ServerKeyExchange was verified */
         ssl_ecrs_ecdh_public_done,      /*!< wrote ECDHE public share       */
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index f91e2a8..f3cde7f 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -4518,6 +4518,7 @@
 #else
     const int authmode = ssl->conf->authmode;
 #endif
+    void *rs_ctx = NULL;
 
     MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse certificate" ) );
 
@@ -4545,11 +4546,20 @@
     {
         ssl->session_negotiate->verify_result = MBEDTLS_X509_BADCERT_SKIP_VERIFY;
         MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse certificate" ) );
+
         ssl->state++;
         return( 0 );
     }
 #endif
 
+#if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
+    if( ssl->handshake->ecrs_enabled &&
+        ssl->handshake->ecrs_state == ssl_ecrs_crt_parsed )
+    {
+        goto crt_verify;
+    }
+#endif
+
     if( ( ret = mbedtls_ssl_read_record( ssl ) ) != 0 )
     {
         /* mbedtls_ssl_read_record may have sent an alert already. We
@@ -4572,6 +4582,15 @@
         return( ret );
     }
 
+#if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
+    if( ssl->handshake->ecrs_enabled)
+        ssl->handshake->ecrs_state++;
+
+crt_verify:
+    if( ssl->handshake->ecrs_enabled)
+        rs_ctx = &ssl->handshake->ecrs_ctx;
+#endif
+
     if( authmode != MBEDTLS_SSL_VERIFY_NONE )
     {
         mbedtls_x509_crt *ca_chain;
@@ -4593,19 +4612,24 @@
         /*
          * Main check: verify certificate
          */
-        ret = mbedtls_x509_crt_verify_with_profile(
+        ret = mbedtls_x509_crt_verify_restartable(
                                 ssl->session_negotiate->peer_cert,
                                 ca_chain, ca_crl,
                                 ssl->conf->cert_profile,
                                 ssl->hostname,
                                &ssl->session_negotiate->verify_result,
-                                ssl->conf->f_vrfy, ssl->conf->p_vrfy );
+                                ssl->conf->f_vrfy, ssl->conf->p_vrfy, rs_ctx );
 
         if( ret != 0 )
         {
             MBEDTLS_SSL_DEBUG_RET( 1, "x509_verify_cert", ret );
         }
 
+#if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
+        if( ret == MBEDTLS_ERR_ECP_IN_PROGRESS )
+            return( ret );
+#endif
+
         /*
          * Secondary checks: always done, but change 'ret' only if it was 0
          */
@@ -4702,6 +4726,11 @@
 #endif /* MBEDTLS_DEBUG_C */
     }
 
+#if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
+    if( ssl->handshake->ecrs_enabled)
+        ssl->handshake->ecrs_state++;
+#endif
+
     ssl->state++;
 
     MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse certificate" ) );
diff --git a/tests/ssl-opt.sh b/tests/ssl-opt.sh
index 2e03758..1dea049 100755
--- a/tests/ssl-opt.sh
+++ b/tests/ssl-opt.sh
@@ -3450,6 +3450,7 @@
              key_file=data_files/server5.key crt_file=data_files/server5.crt  \
              debug_level=1" \
             0 \
+            -C "x509_verify_cert.*4b80" \
             -C "mbedtls_pk_verify.*4b80" \
             -C "mbedtls_ecdh_make_public.*4b80" \
             -C "mbedtls_pk_sign.*4b80"
@@ -3461,6 +3462,7 @@
              key_file=data_files/server5.key crt_file=data_files/server5.crt  \
              debug_level=1 ec_max_ops=0" \
             0 \
+            -C "x509_verify_cert.*4b80" \
             -C "mbedtls_pk_verify.*4b80" \
             -C "mbedtls_ecdh_make_public.*4b80" \
             -C "mbedtls_pk_sign.*4b80"
@@ -3472,6 +3474,7 @@
              key_file=data_files/server5.key crt_file=data_files/server5.crt  \
              debug_level=1 ec_max_ops=65535" \
             0 \
+            -C "x509_verify_cert.*4b80" \
             -C "mbedtls_pk_verify.*4b80" \
             -C "mbedtls_ecdh_make_public.*4b80" \
             -C "mbedtls_pk_sign.*4b80"
@@ -3483,17 +3486,70 @@
              key_file=data_files/server5.key crt_file=data_files/server5.crt  \
              debug_level=1 ec_max_ops=1000" \
             0 \
+            -c "x509_verify_cert.*4b80" \
             -c "mbedtls_pk_verify.*4b80" \
             -c "mbedtls_ecdh_make_public.*4b80" \
             -c "mbedtls_pk_sign.*4b80"
 
 requires_config_enabled MBEDTLS_ECP_RESTARTABLE
+run_test    "EC restart: TLS, max_ops=1000, badsign" \
+            "$P_SRV auth_mode=required \
+             crt_file=data_files/server5-badsign.crt \
+             key_file=data_files/server5.key" \
+            "$P_CLI force_ciphersuite=TLS-ECDHE-ECDSA-WITH-AES-128-GCM-SHA256 \
+             key_file=data_files/server5.key crt_file=data_files/server5.crt  \
+             debug_level=1 ec_max_ops=1000" \
+            1 \
+            -c "x509_verify_cert.*4b80" \
+            -C "mbedtls_pk_verify.*4b80" \
+            -C "mbedtls_ecdh_make_public.*4b80" \
+            -C "mbedtls_pk_sign.*4b80" \
+            -c "! The certificate is not correctly signed by the trusted CA" \
+            -c "! mbedtls_ssl_handshake returned" \
+            -c "X509 - Certificate verification failed"
+
+requires_config_enabled MBEDTLS_ECP_RESTARTABLE
+run_test    "EC restart: TLS, max_ops=1000, auth_mode=optional badsign" \
+            "$P_SRV auth_mode=required \
+             crt_file=data_files/server5-badsign.crt \
+             key_file=data_files/server5.key" \
+            "$P_CLI force_ciphersuite=TLS-ECDHE-ECDSA-WITH-AES-128-GCM-SHA256 \
+             key_file=data_files/server5.key crt_file=data_files/server5.crt  \
+             debug_level=1 ec_max_ops=1000 auth_mode=optional" \
+            0 \
+            -c "x509_verify_cert.*4b80" \
+            -c "mbedtls_pk_verify.*4b80" \
+            -c "mbedtls_ecdh_make_public.*4b80" \
+            -c "mbedtls_pk_sign.*4b80" \
+            -c "! The certificate is not correctly signed by the trusted CA" \
+            -C "! mbedtls_ssl_handshake returned" \
+            -C "X509 - Certificate verification failed"
+
+requires_config_enabled MBEDTLS_ECP_RESTARTABLE
+run_test    "EC restart: TLS, max_ops=1000, auth_mode=none badsign" \
+            "$P_SRV auth_mode=required \
+             crt_file=data_files/server5-badsign.crt \
+             key_file=data_files/server5.key" \
+            "$P_CLI force_ciphersuite=TLS-ECDHE-ECDSA-WITH-AES-128-GCM-SHA256 \
+             key_file=data_files/server5.key crt_file=data_files/server5.crt  \
+             debug_level=1 ec_max_ops=1000 auth_mode=none" \
+            0 \
+            -C "x509_verify_cert.*4b80" \
+            -c "mbedtls_pk_verify.*4b80" \
+            -c "mbedtls_ecdh_make_public.*4b80" \
+            -c "mbedtls_pk_sign.*4b80" \
+            -C "! The certificate is not correctly signed by the trusted CA" \
+            -C "! mbedtls_ssl_handshake returned" \
+            -C "X509 - Certificate verification failed"
+
+requires_config_enabled MBEDTLS_ECP_RESTARTABLE
 run_test    "EC restart: DTLS, max_ops=1000" \
             "$P_SRV auth_mode=required dtls=1" \
             "$P_CLI force_ciphersuite=TLS-ECDHE-ECDSA-WITH-AES-128-GCM-SHA256 \
              key_file=data_files/server5.key crt_file=data_files/server5.crt  \
              dtls=1 debug_level=1 ec_max_ops=1000" \
             0 \
+            -c "x509_verify_cert.*4b80" \
             -c "mbedtls_pk_verify.*4b80" \
             -c "mbedtls_ecdh_make_public.*4b80" \
             -c "mbedtls_pk_sign.*4b80"
@@ -3504,6 +3560,7 @@
             "$P_CLI force_ciphersuite=TLS-ECDHE-ECDSA-WITH-AES-128-GCM-SHA256 \
              debug_level=1 ec_max_ops=1000" \
             0 \
+            -c "x509_verify_cert.*4b80" \
             -c "mbedtls_pk_verify.*4b80" \
             -c "mbedtls_ecdh_make_public.*4b80" \
             -C "mbedtls_pk_sign.*4b80"
@@ -3514,6 +3571,7 @@
             "$P_CLI force_ciphersuite=TLS-ECDHE-PSK-WITH-AES-128-CBC-SHA256 \
              psk=abc123 debug_level=1 ec_max_ops=1000" \
             0 \
+            -C "x509_verify_cert.*4b80" \
             -C "mbedtls_pk_verify.*4b80" \
             -C "mbedtls_ecdh_make_public.*4b80" \
             -C "mbedtls_pk_sign.*4b80"