diff --git a/library/ssl_cli.c b/library/ssl_cli.c
index 1140d9e..d7a5dac 100644
--- a/library/ssl_cli.c
+++ b/library/ssl_cli.c
@@ -53,6 +53,7 @@
 #endif
 
 #if defined(MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED)
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_conf_has_static_psk( mbedtls_ssl_config const *conf )
 {
     if( conf->psk_identity     == NULL ||
@@ -73,6 +74,7 @@
 }
 
 #if defined(MBEDTLS_USE_PSA_CRYPTO)
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_conf_has_static_raw_psk( mbedtls_ssl_config const *conf )
 {
     if( conf->psk_identity     == NULL ||
@@ -91,6 +93,7 @@
 #endif /* MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED */
 
 #if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_write_hostname_ext( mbedtls_ssl_context *ssl,
                                    unsigned char *buf,
                                    const unsigned char *end,
@@ -161,6 +164,7 @@
 #endif /* MBEDTLS_SSL_SERVER_NAME_INDICATION */
 
 #if defined(MBEDTLS_SSL_RENEGOTIATION)
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_write_renegotiation_ext( mbedtls_ssl_context *ssl,
                                         unsigned char *buf,
                                         const unsigned char *end,
@@ -204,6 +208,7 @@
  */
 #if defined(MBEDTLS_SSL_PROTO_TLS1_2) && \
     defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_write_signature_algorithms_ext( mbedtls_ssl_context *ssl,
                                                unsigned char *buf,
                                                const unsigned char *end,
@@ -302,6 +307,7 @@
 
 #if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) || \
     defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_write_supported_elliptic_curves_ext( mbedtls_ssl_context *ssl,
                                                     unsigned char *buf,
                                                     const unsigned char *end,
@@ -373,6 +379,7 @@
     return( 0 );
 }
 
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_write_supported_point_formats_ext( mbedtls_ssl_context *ssl,
                                                   unsigned char *buf,
                                                   const unsigned char *end,
@@ -404,6 +411,7 @@
           MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
 
 #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_write_ecjpake_kkpp_ext( mbedtls_ssl_context *ssl,
                                        unsigned char *buf,
                                        const unsigned char *end,
@@ -477,6 +485,7 @@
 #endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
 
 #if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_write_cid_ext( mbedtls_ssl_context *ssl,
                               unsigned char *buf,
                               const unsigned char *end,
@@ -523,6 +532,7 @@
 #endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
 
 #if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_write_max_fragment_length_ext( mbedtls_ssl_context *ssl,
                                               unsigned char *buf,
                                               const unsigned char *end,
@@ -555,6 +565,7 @@
 #endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */
 
 #if defined(MBEDTLS_SSL_TRUNCATED_HMAC)
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_write_truncated_hmac_ext( mbedtls_ssl_context *ssl,
                                          unsigned char *buf,
                                          const unsigned char *end,
@@ -585,6 +596,7 @@
 #endif /* MBEDTLS_SSL_TRUNCATED_HMAC */
 
 #if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_write_encrypt_then_mac_ext( mbedtls_ssl_context *ssl,
                                            unsigned char *buf,
                                            const unsigned char *end,
@@ -616,6 +628,7 @@
 #endif /* MBEDTLS_SSL_ENCRYPT_THEN_MAC */
 
 #if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET)
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_write_extended_ms_ext( mbedtls_ssl_context *ssl,
                                       unsigned char *buf,
                                       const unsigned char *end,
@@ -647,6 +660,7 @@
 #endif /* MBEDTLS_SSL_EXTENDED_MASTER_SECRET */
 
 #if defined(MBEDTLS_SSL_SESSION_TICKETS)
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_write_session_ticket_ext( mbedtls_ssl_context *ssl,
                                          unsigned char *buf,
                                          const unsigned char *end,
@@ -689,6 +703,7 @@
 #endif /* MBEDTLS_SSL_SESSION_TICKETS */
 
 #if defined(MBEDTLS_SSL_ALPN)
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_write_alpn_ext( mbedtls_ssl_context *ssl,
                                unsigned char *buf,
                                const unsigned char *end,
@@ -748,6 +763,7 @@
 #endif /* MBEDTLS_SSL_ALPN */
 
 #if defined(MBEDTLS_SSL_DTLS_SRTP)
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_write_use_srtp_ext( mbedtls_ssl_context *ssl,
                                    unsigned char *buf,
                                    const unsigned char *end,
@@ -868,6 +884,7 @@
 /*
  * Generate random bytes for ClientHello
  */
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_generate_random( mbedtls_ssl_context *ssl )
 {
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
@@ -917,6 +934,7 @@
  *
  * \return          0 if valid, else 1
  */
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_validate_ciphersuite(
     const mbedtls_ssl_ciphersuite_t * suite_info,
     const mbedtls_ssl_context * ssl,
@@ -960,6 +978,7 @@
     return( 0 );
 }
 
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_write_client_hello( mbedtls_ssl_context *ssl )
 {
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
@@ -1450,6 +1469,7 @@
     return( 0 );
 }
 
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_parse_renegotiation_info( mbedtls_ssl_context *ssl,
                                          const unsigned char *buf,
                                          size_t len )
@@ -1494,6 +1514,7 @@
 }
 
 #if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_parse_max_fragment_length_ext( mbedtls_ssl_context *ssl,
                                               const unsigned char *buf,
                                               size_t len )
@@ -1520,6 +1541,7 @@
 #endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */
 
 #if defined(MBEDTLS_SSL_TRUNCATED_HMAC)
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_parse_truncated_hmac_ext( mbedtls_ssl_context *ssl,
                                          const unsigned char *buf,
                                          size_t len )
@@ -1545,6 +1567,7 @@
 #endif /* MBEDTLS_SSL_TRUNCATED_HMAC */
 
 #if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_parse_cid_ext( mbedtls_ssl_context *ssl,
                               const unsigned char *buf,
                               size_t len )
@@ -1601,6 +1624,7 @@
 #endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
 
 #if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_parse_encrypt_then_mac_ext( mbedtls_ssl_context *ssl,
                                          const unsigned char *buf,
                                          size_t len )
@@ -1627,6 +1651,7 @@
 #endif /* MBEDTLS_SSL_ENCRYPT_THEN_MAC */
 
 #if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET)
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_parse_extended_ms_ext( mbedtls_ssl_context *ssl,
                                          const unsigned char *buf,
                                          size_t len )
@@ -1653,6 +1678,7 @@
 #endif /* MBEDTLS_SSL_EXTENDED_MASTER_SECRET */
 
 #if defined(MBEDTLS_SSL_SESSION_TICKETS)
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_parse_session_ticket_ext( mbedtls_ssl_context *ssl,
                                          const unsigned char *buf,
                                          size_t len )
@@ -1679,6 +1705,7 @@
 
 #if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) || \
     defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_parse_supported_point_formats_ext( mbedtls_ssl_context *ssl,
                                                   const unsigned char *buf,
                                                   size_t len )
@@ -1724,6 +1751,7 @@
           MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
 
 #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_parse_ecjpake_kkpp( mbedtls_ssl_context *ssl,
                                    const unsigned char *buf,
                                    size_t len )
@@ -1758,6 +1786,7 @@
 #endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
 
 #if defined(MBEDTLS_SSL_ALPN)
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_parse_alpn_ext( mbedtls_ssl_context *ssl,
                                const unsigned char *buf, size_t len )
 {
@@ -1828,6 +1857,7 @@
 #endif /* MBEDTLS_SSL_ALPN */
 
 #if defined(MBEDTLS_SSL_DTLS_SRTP)
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_parse_use_srtp_ext( mbedtls_ssl_context *ssl,
                                    const unsigned char *buf,
                                    size_t len )
@@ -1948,6 +1978,7 @@
  * Parse HelloVerifyRequest.  Only called after verifying the HS type.
  */
 #if defined(MBEDTLS_SSL_PROTO_DTLS)
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_parse_hello_verify_request( mbedtls_ssl_context *ssl )
 {
     const unsigned char *p = ssl->in_msg + mbedtls_ssl_hs_hdr_len( ssl );
@@ -2031,6 +2062,7 @@
 }
 #endif /* MBEDTLS_SSL_PROTO_DTLS */
 
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_parse_server_hello( mbedtls_ssl_context *ssl )
 {
     int ret, i;
@@ -2591,6 +2623,7 @@
 
 #if defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED) ||                       \
     defined(MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED)
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_parse_server_dh_params( mbedtls_ssl_context *ssl,
                                        unsigned char **p,
                                        unsigned char *end )
@@ -2637,6 +2670,7 @@
     defined(MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED) ||                     \
     defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) ||                      \
     defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_check_server_ecdh_params( const mbedtls_ssl_context *ssl )
 {
     const mbedtls_ecp_curve_info *curve_info;
@@ -2678,6 +2712,7 @@
 #if defined(MBEDTLS_USE_PSA_CRYPTO) &&                           \
         ( defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) ||     \
           defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) )
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_parse_server_ecdh_params_psa( mbedtls_ssl_context *ssl,
                                              unsigned char **p,
                                              unsigned char *end )
@@ -2744,6 +2779,7 @@
 #if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) ||                     \
     defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) ||                   \
     defined(MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED)
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_parse_server_ecdh_params( mbedtls_ssl_context *ssl,
                                          unsigned char **p,
                                          unsigned char *end )
@@ -2783,6 +2819,7 @@
           MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED */
 
 #if defined(MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED)
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_parse_server_psk_hint( mbedtls_ssl_context *ssl,
                                       unsigned char **p,
                                       unsigned char *end )
@@ -2829,6 +2866,7 @@
 /*
  * Generate a pre-master secret and encrypt it with the server's RSA key
  */
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_write_encrypted_pms( mbedtls_ssl_context *ssl,
                                     size_t offset, size_t *olen,
                                     size_t pms_offset )
@@ -2916,6 +2954,7 @@
 #if defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED) ||                       \
     defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) ||                     \
     defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_parse_signature_algorithm( mbedtls_ssl_context *ssl,
                                           unsigned char **p,
                                           unsigned char *end,
@@ -2982,6 +3021,7 @@
 
 #if defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) || \
     defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_get_ecdh_params_from_cert( mbedtls_ssl_context *ssl )
 {
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
@@ -3035,6 +3075,7 @@
 #endif /* MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) ||
           MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED */
 
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_parse_server_key_exchange( mbedtls_ssl_context *ssl )
 {
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
@@ -3441,6 +3482,7 @@
 }
 
 #if ! defined(MBEDTLS_KEY_EXCHANGE_CERT_REQ_ALLOWED_ENABLED)
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_parse_certificate_request( mbedtls_ssl_context *ssl )
 {
     const mbedtls_ssl_ciphersuite_t *ciphersuite_info =
@@ -3459,6 +3501,7 @@
     return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
 }
 #else /* MBEDTLS_KEY_EXCHANGE_CERT_REQ_ALLOWED_ENABLED */
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_parse_certificate_request( mbedtls_ssl_context *ssl )
 {
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
@@ -3630,6 +3673,7 @@
 }
 #endif /* MBEDTLS_KEY_EXCHANGE_CERT_REQ_ALLOWED_ENABLED */
 
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_parse_server_hello_done( mbedtls_ssl_context *ssl )
 {
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
@@ -3669,6 +3713,7 @@
     return( 0 );
 }
 
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_write_client_key_exchange( mbedtls_ssl_context *ssl )
 {
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
@@ -4101,6 +4146,7 @@
 }
 
 #if !defined(MBEDTLS_KEY_EXCHANGE_CERT_REQ_ALLOWED_ENABLED)
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_write_certificate_verify( mbedtls_ssl_context *ssl )
 {
     const mbedtls_ssl_ciphersuite_t *ciphersuite_info =
@@ -4126,6 +4172,7 @@
     return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
 }
 #else /* !MBEDTLS_KEY_EXCHANGE_CERT_REQ_ALLOWED_ENABLED */
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_write_certificate_verify( mbedtls_ssl_context *ssl )
 {
     int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE;
@@ -4298,6 +4345,7 @@
 #endif /* MBEDTLS_KEY_EXCHANGE_CERT_REQ_ALLOWED_ENABLED */
 
 #if defined(MBEDTLS_SSL_SESSION_TICKETS)
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_parse_new_session_ticket( mbedtls_ssl_context *ssl )
 {
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;