update based on comments.

Signed-off-by: Xiaofei Bai <xiaofei.bai@arm.com>
diff --git a/library/ssl_misc.h b/library/ssl_misc.h
index 1db6202..c2ce077 100644
--- a/library/ssl_misc.h
+++ b/library/ssl_misc.h
@@ -809,10 +809,9 @@
                                              represents an extension and defined
                                              as \c MBEDTLS_SSL_EXT_XXX */
 
-#if defined(MBEDTLS_ECDSA_C)
-    unsigned char cert_req_ctx_len;     /*!< certificate request context
-                                             length */
-    unsigned char* cert_req_ctx;        /*!< certificate request context */
+#if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
+    unsigned char certificate_request_context_len;
+    unsigned char *certificate_request_context;
 #endif
 
     union
diff --git a/library/ssl_tls13_client.c b/library/ssl_tls13_client.c
index 83ee98f..23b0670 100644
--- a/library/ssl_tls13_client.c
+++ b/library/ssl_tls13_client.c
@@ -1398,6 +1398,272 @@
     return( 0 );
 }
 
+#if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)
+static int ssl_tls13_parse_signature_algorithms_ext( mbedtls_ssl_context *ssl,
+                                                     const unsigned char *buf,
+                                                     const unsigned char *end )
+{
+    size_t sig_alg_list_size; /* size of receive signature algorithms list */
+    const unsigned char *p; /* pointer to individual signature algorithm */
+    const uint16_t *sig_alg; /* iterate through configured signature schemes */
+    unsigned int signature_scheme; /* store received signature algorithm scheme */
+    uint32_t common_idx = 0; /* iterate through received_signature_schemes_list */
+    size_t buf_len = end - buf;
+
+    MBEDTLS_SSL_CHK_BUF_READ_PTR( buf, end, 2 );
+
+    sig_alg_list_size = MBEDTLS_GET_UINT16_BE( buf, 0 );
+    if( sig_alg_list_size + 2 != buf_len ||
+        sig_alg_list_size % 2 != 0 )
+    {
+        MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad signature_algorithms extension" ) );
+        return( MBEDTLS_ERR_SSL_DECODE_ERROR );
+    }
+    memset( ssl->handshake->recv_sig_schemes_list, 0,
+            sizeof( ssl->handshake->recv_sig_schemes_list ) );
+
+    for( p = buf + 2; p < end && common_idx + 1 < MBEDTLS_PK_SIGNATURE_MAX_SIZE; p += 2 )
+    {
+        signature_scheme = MBEDTLS_GET_UINT16_BE( p, 0 );
+
+        MBEDTLS_SSL_DEBUG_MSG( 4, ( "received signature algorithm: 0x%x",
+                                    signature_scheme ) );
+
+        for( sig_alg = ssl->conf->tls13_sig_algs;
+             *sig_alg != MBEDTLS_TLS1_3_SIG_NONE; sig_alg++ )
+        {
+            if( *sig_alg == signature_scheme )
+            {
+                ssl->handshake->recv_sig_schemes_list[common_idx] = signature_scheme;
+                common_idx++;
+                break;
+            }
+        }
+    }
+
+    if( common_idx == 0 )
+    {
+        MBEDTLS_SSL_DEBUG_MSG( 3, ( "no signature algorithm in common" ) );
+        MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE,
+                                      MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
+        return( MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
+    }
+
+    ssl->handshake->recv_sig_schemes_list[common_idx] = MBEDTLS_TLS1_3_SIG_NONE;
+
+    return( 0 );
+}
+#endif /* MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED */
+
+/*
+ *
+ * STATE HANDLING: CertificateRequest
+ *
+ */
+
+/*
+ * Overview
+ */
+
+/* Coordination:
+ * Deals with the ambiguity of not knowing if a CertificateRequest
+ * will be sent. Returns a negative code on failure, or
+ * - SSL_CERTIFICATE_REQUEST_EXPECT_REQUEST
+ * - SSL_CERTIFICATE_REQUEST_SKIP
+ * indicating if a Certificate Request is expected or not.
+ */
+#define SSL_CERTIFICATE_REQUEST_EXPECT_REQUEST 0
+#define SSL_CERTIFICATE_REQUEST_SKIP    1
+
+/*
+ * Implementation
+ */
+
+static int ssl_tls13_certificate_request_coordinate( mbedtls_ssl_context *ssl )
+{
+    int ret;
+
+    if( mbedtls_ssl_tls13_psk_enabled( ssl ) )
+    {
+        MBEDTLS_SSL_DEBUG_MSG( 3, ( "<= skip parse certificate request" ) );
+        return( SSL_CERTIFICATE_REQUEST_SKIP );
+    }
+
+    if( ( ret = mbedtls_ssl_read_record( ssl, 0 ) ) != 0 )
+    {
+        MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_read_record", ret );
+        return( ret );
+    }
+    ssl->keep_current_message = 1;
+
+    if( ssl->in_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE )
+    {
+        MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate request message" ) );
+        MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_UNEXPECTED_MESSAGE,
+                                      MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
+        return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
+    }
+
+    if( ssl->in_msg[0] == MBEDTLS_SSL_HS_CERTIFICATE_REQUEST )
+    {
+        return( SSL_CERTIFICATE_REQUEST_EXPECT_REQUEST );
+    }
+
+    return( SSL_CERTIFICATE_REQUEST_SKIP );
+}
+
+#if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)
+/*
+ * ssl_tls13_parse_certificate_request()
+ *     Parse certificate request
+ * struct {
+ *   opaque certificate_request_context<0..2^8-1>;
+ *   Extension extensions<2..2^16-1>;
+ * } CertificateRequest;
+ */
+static int ssl_tls13_parse_certificate_request( mbedtls_ssl_context *ssl,
+                                                const unsigned char *buf,
+                                                const unsigned char *end )
+{
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+    const unsigned char *p = buf;
+    const unsigned char *extensions_end;
+    size_t extensions_len = 0;
+    size_t certificate_request_context_len = 0;
+
+    /* Parse certificate_request_context */
+    MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, 1 );
+    certificate_request_context_len = (size_t) p[0];
+    p++;
+
+    /* store context ( if necessary ) */
+    if( certificate_request_context_len > 0 )
+    {
+        MBEDTLS_SSL_DEBUG_BUF( 3, "Certificate Request Context",
+                               p, certificate_request_context_len );
+
+        ssl->handshake->certificate_request_context =
+                mbedtls_calloc( certificate_request_context_len, 1 );
+        if( ssl->handshake->certificate_request_context == NULL )
+        {
+            MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
+            return ( MBEDTLS_ERR_SSL_ALLOC_FAILED );
+        }
+        MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, certificate_request_context_len );
+        memcpy( ssl->handshake->certificate_request_context, p,
+                certificate_request_context_len );
+
+        /* jump over certificate_request_context */
+        p += certificate_request_context_len;
+    }
+
+    /*
+     * Parse extensions
+     */
+    MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, 2 );
+    extensions_len = MBEDTLS_GET_UINT16_BE( p, 0 );
+    p += 2;
+
+    MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, extensions_len );
+    extensions_end = p + extensions_len;
+
+    while( p < extensions_end )
+    {
+        unsigned int extension_type;
+        size_t extension_data_len;
+
+        MBEDTLS_SSL_CHK_BUF_READ_PTR( p, extensions_end, 4 );
+        extension_type = MBEDTLS_GET_UINT16_BE( p, 0 );
+        extension_data_len = MBEDTLS_GET_UINT16_BE( p, 2 );
+        p += 4;
+
+        MBEDTLS_SSL_CHK_BUF_READ_PTR( p, extensions_end, extension_data_len );
+
+        switch( extension_type )
+        {
+            case MBEDTLS_TLS_EXT_SIG_ALG:
+                MBEDTLS_SSL_DEBUG_MSG( 3,
+                        ( "found signature_algorithms extension" ) );
+
+                ret = ssl_tls13_parse_signature_algorithms_ext( ssl, p,
+                              p + extension_data_len );
+                if( ret != 0 )
+                    return( ret );
+                break;
+
+            default:
+                MBEDTLS_SSL_DEBUG_MSG(
+                    3,
+                    ( "unknown extension found: %u ( ignoring )",
+                    extension_type ) );
+
+                MBEDTLS_SSL_PEND_FATAL_ALERT(
+                    MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_EXT,
+                    MBEDTLS_ERR_SSL_UNSUPPORTED_EXTENSION );
+                return( MBEDTLS_ERR_SSL_UNSUPPORTED_EXTENSION );
+        }
+
+        p += extension_data_len;
+    }
+
+    ssl->client_auth = 1;
+    return( 0 );
+}
+#endif /* ( MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED ) */
+
+/* Main entry point; orchestrates the other functions */
+int mbedtls_ssl_tls13_process_certificate_request( mbedtls_ssl_context *ssl )
+{
+    int ret = 0;
+
+    MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse certificate request" ) );
+
+    /* Coordination step
+     * - Fetch record
+     * - Make sure it's either a CertificateRequest or a ServerHelloDone
+     */
+    MBEDTLS_SSL_PROC_CHK_NEG( ssl_tls13_certificate_request_coordinate( ssl ) );
+
+#if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)
+    if( ret == SSL_CERTIFICATE_REQUEST_EXPECT_REQUEST )
+    {
+        unsigned char *buf;
+        size_t buf_len;
+
+        MBEDTLS_SSL_PROC_CHK( mbedtls_ssl_tls13_fetch_handshake_msg( ssl,
+                                            MBEDTLS_SSL_HS_CERTIFICATE_REQUEST,
+                                            &buf, &buf_len ) );
+
+        MBEDTLS_SSL_PROC_CHK( ssl_tls13_parse_certificate_request( ssl,
+                                              buf, buf + buf_len ) );
+
+        mbedtls_ssl_tls13_add_hs_msg_to_checksum(
+                       ssl, MBEDTLS_SSL_HS_CERTIFICATE_REQUEST, buf, buf_len );
+    }
+    else
+#endif /* MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED */
+    if( ret == SSL_CERTIFICATE_REQUEST_SKIP )
+    {
+        MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse certificate request" ) );
+    }
+    else
+    {
+        MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
+        return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
+    }
+
+    MBEDTLS_SSL_DEBUG_MSG( 3, ( "got %s certificate request",
+                                ssl->client_auth ? "a" : "no" ) );
+
+cleanup:
+
+    /* In the MPS one would close the read-port here to
+     * ensure there's no overlap of reading and writing. */
+
+    MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse certificate request" ) );
+    return( ret );
+}
+
 #if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
 /*
  * Handler for  MBEDTLS_SSL_CERTIFICATE_REQUEST
@@ -1412,13 +1678,9 @@
         return( ret );
     }
 
-    if( ( ssl->in_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE ) &&
-        ( ssl->in_msg[0] == MBEDTLS_SSL_HS_CERTIFICATE_REQUEST ) )
-    {
-        ret = mbedtls_ssl_tls13_process_certificate_request( ssl );
-        if( ret != 0 )
-            return( ret );
-    }
+    ret = mbedtls_ssl_tls13_process_certificate_request( ssl );
+    if( ret != 0 )
+        return( ret );
 
     ssl->keep_current_message = 1;
     mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_SERVER_CERTIFICATE );
diff --git a/library/ssl_tls13_generic.c b/library/ssl_tls13_generic.c
index 90c20bd..650f9ba 100644
--- a/library/ssl_tls13_generic.c
+++ b/library/ssl_tls13_generic.c
@@ -220,295 +220,6 @@
     return( 0 );
 }
 
-#if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)
-static int ssl_tls13_parse_signature_algorithms_ext( mbedtls_ssl_context *ssl,
-                                                     const unsigned char *buf,
-                                                     const unsigned char *end )
-{
-    size_t sig_alg_list_size; /* size of receive signature algorithms list */
-    const unsigned char *p; /* pointer to individual signature algorithm */
-    const uint16_t *sig_alg; /* iterate through configured signature schemes */
-    unsigned int signature_scheme; /* store received signature algorithm scheme */
-    uint32_t common_idx = 0; /* iterate through received_signature_schemes_list */
-    size_t buf_len = end - buf;
-
-    MBEDTLS_SSL_CHK_BUF_READ_PTR( buf, end, 2 );
-
-    sig_alg_list_size = MBEDTLS_GET_UINT16_BE( buf, 0 );
-    if( sig_alg_list_size + 2 != buf_len ||
-        sig_alg_list_size % 2 != 0 )
-    {
-        MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad signature_algorithms extension" ) );
-        return( MBEDTLS_ERR_SSL_DECODE_ERROR );
-    }
-    memset( ssl->handshake->recv_sig_schemes_list, 0,
-            sizeof( ssl->handshake->recv_sig_schemes_list ) );
-
-    for( p = buf + 2; p < end && common_idx + 1 < MBEDTLS_PK_SIGNATURE_MAX_SIZE; p += 2 )
-    {
-        signature_scheme = MBEDTLS_GET_UINT16_BE( p, 0 );
-
-        MBEDTLS_SSL_DEBUG_MSG( 4, ( "received signature algorithm: 0x%x",
-                                    signature_scheme ) );
-
-        for( sig_alg = ssl->conf->tls13_sig_algs;
-             *sig_alg != MBEDTLS_TLS1_3_SIG_NONE; sig_alg++ )
-        {
-            if( *sig_alg == signature_scheme )
-            {
-                ssl->handshake->recv_sig_schemes_list[common_idx] = signature_scheme;
-                common_idx++;
-                break;
-            }
-        }
-    }
-
-    if( common_idx == 0 )
-    {
-        MBEDTLS_SSL_DEBUG_MSG( 3, ( "no signature algorithm in common" ) );
-        MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE,
-                                      MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
-        return( MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
-    }
-
-    ssl->handshake->recv_sig_schemes_list[common_idx] = MBEDTLS_TLS1_3_SIG_NONE;
-
-    return( 0 );
-}
-#endif
-
-/*
- *
- * STATE HANDLING: CertificateRequest
- *
- */
-
-/*
- * Overview
- */
-
-/* Coordination:
- * Deals with the ambiguity of not knowing if a CertificateRequest
- * will be sent. Returns a negative code on failure, or
- * - SSL_CERTIFICATE_REQUEST_EXPECT_REQUEST
- * - SSL_CERTIFICATE_REQUEST_SKIP
- * indicating if a Certificate Request is expected or not.
- */
-#define SSL_CERTIFICATE_REQUEST_EXPECT_REQUEST 0
-#define SSL_CERTIFICATE_REQUEST_SKIP    1
-
-/*
- * Implementation
- */
-
-static int ssl_tls13_certificate_request_coordinate( mbedtls_ssl_context *ssl )
-{
-    int ret;
-
-    if( mbedtls_ssl_tls13_psk_enabled( ssl ) )
-    {
-        MBEDTLS_SSL_DEBUG_MSG( 3, ( "<= skip parse certificate request" ) );
-        return( SSL_CERTIFICATE_REQUEST_SKIP );
-    }
-
-    if( ( ret = mbedtls_ssl_read_record( ssl, 0 ) ) != 0 )
-    {
-        MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_read_record", ret );
-        return( ret );
-    }
-    ssl->keep_current_message = 1;
-
-    if( ssl->in_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE )
-    {
-        MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate request message" ) );
-        MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_UNEXPECTED_MESSAGE,
-                                      MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
-        return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
-    }
-
-    return( SSL_CERTIFICATE_REQUEST_SKIP );
-}
-
-#if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)
-static int ssl_tls13_parse_certificate_request( mbedtls_ssl_context *ssl,
-                                                const unsigned char *buf,
-                                                const unsigned char *end )
-{
-    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
-    const unsigned char *p = buf;
-    const unsigned char *ext = NULL;
-    size_t ext_len = 0;
-    size_t context_len = 0;
-
-
-    /*
-     * struct {
-     *   opaque certificate_request_context<0..2^8-1>;
-     *   Extension extensions<2..2^16-1>;
-     * } CertificateRequest;
-     */
-
-    /*
-     * Parse certificate_request_context
-     */
-
-    MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, 1 );
-    context_len = (size_t) p[0];
-    /* skip context_len */
-    p++;
-
-    /* Fixed length fields are:
-     *  - 1 for length of context
-     *  - 2 for length of extensions
-     * -----
-     *    3 bytes
-     */
-    MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, 3 );
-
-    /* store context ( if necessary ) */
-    if( context_len > 0 )
-    {
-        MBEDTLS_SSL_DEBUG_BUF( 3, "Certificate Request Context",
-                               p, context_len );
-
-        ssl->handshake->cert_req_ctx = mbedtls_calloc( context_len, 1 );
-        if( ssl->handshake->cert_req_ctx == NULL )
-        {
-            MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
-            return ( MBEDTLS_ERR_SSL_ALLOC_FAILED );
-        }
-        memcpy( ssl->handshake->cert_req_ctx, p, context_len );
-
-        /* jump over certificate_request_context */
-        p += context_len;
-    }
-
-    /*
-     * Parse extensions
-     */
-    ext_len = MBEDTLS_GET_UINT16_BE( p, 0 );
-
-    /* At least one extension needs to be present,
-     * namely signature_algorithms ext. */
-    if( ext_len < 4 )
-    {
-        MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate request message" ) );
-        MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR,
-                                      MBEDTLS_ERR_SSL_DECODE_ERROR );
-        return( MBEDTLS_ERR_SSL_DECODE_ERROR );
-    }
-
-    /* skip total extension length */
-    p += 2;
-
-    ext = p; /* jump to extensions */
-    while( ext_len )
-    {
-        size_t ext_id = MBEDTLS_GET_UINT16_BE( ext, 0 );
-        size_t ext_size = MBEDTLS_GET_UINT16_BE( ext, 1 );
-
-        if( ext_size + 4 > ext_len )
-        {
-            MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate request message" ) );
-            MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR,
-                                          MBEDTLS_ERR_SSL_DECODE_ERROR );
-            return( MBEDTLS_ERR_SSL_DECODE_ERROR );
-        }
-
-        switch( ext_id )
-        {
-            case MBEDTLS_TLS_EXT_SIG_ALG:
-                MBEDTLS_SSL_DEBUG_MSG( 3,
-                        ( "found signature_algorithms extension" ) );
-
-                if( ( ret = ssl_tls13_parse_signature_algorithms_ext( ssl,
-                            ext + 4, ext + 4 + ext_size ) ) != 0 )
-                {
-                    MBEDTLS_SSL_DEBUG_RET( 1,
-                        "ssl_tls13_parse_signature_algorithms_ext", ret );
-                    MBEDTLS_SSL_PEND_FATAL_ALERT(
-                        MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR, ret );
-                    return( ret );
-                }
-                break;
-
-            default:
-                MBEDTLS_SSL_DEBUG_MSG( 3,
-                ( "unknown extension found: %" MBEDTLS_PRINTF_SIZET " ( ignoring )",
-                  ext_id ) );
-                break;
-        }
-
-        ext_len -= 4 + ext_size;
-        ext += 4 + ext_size;
-
-        if( ( ext_len > 0 ) && ( ext_len < 4 ) )
-        {
-            MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate request message" ) );
-            MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR,
-                                          MBEDTLS_ERR_SSL_DECODE_ERROR );
-            return( MBEDTLS_ERR_SSL_DECODE_ERROR );
-        }
-    }
-
-    ssl->client_auth = 1;
-    return( 0 );
-}
-#endif /* ( MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED ) */
-
-/* Main entry point; orchestrates the other functions */
-int mbedtls_ssl_tls13_process_certificate_request( mbedtls_ssl_context *ssl )
-{
-    int ret = 0;
-
-    MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse certificate request" ) );
-
-    /* Coordination step
-     * - Fetch record
-     * - Make sure it's either a CertificateRequest or a ServerHelloDone
-     */
-    MBEDTLS_SSL_PROC_CHK_NEG( ssl_tls13_certificate_request_coordinate( ssl ) );
-
-#if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)
-    if( ret == SSL_CERTIFICATE_REQUEST_EXPECT_REQUEST )
-    {
-        unsigned char *buf;
-        size_t buf_len;
-
-        MBEDTLS_SSL_PROC_CHK( mbedtls_ssl_tls13_fetch_handshake_msg( ssl,
-                                            MBEDTLS_SSL_HS_CERTIFICATE_REQUEST,
-                                            &buf, &buf_len ) );
-
-        MBEDTLS_SSL_PROC_CHK( ssl_tls13_parse_certificate_request( ssl,
-                                              buf, buf + buf_len ) );
-
-        mbedtls_ssl_tls13_add_hs_msg_to_checksum(
-                       ssl, MBEDTLS_SSL_HS_CERTIFICATE_REQUEST, buf, buf_len );
-    }
-    else
-#endif /* MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED */
-    if( ret == SSL_CERTIFICATE_REQUEST_SKIP )
-    {
-        MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse certificate request" ) );
-    }
-    else
-    {
-        MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
-        return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
-    }
-
-    MBEDTLS_SSL_DEBUG_MSG( 3, ( "got %s certificate request",
-                                ssl->client_auth ? "a" : "no" ) );
-
-cleanup:
-
-    /* In the MPS one would close the read-port here to
-     * ensure there's no overlap of reading and writing. */
-
-    MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse certificate request" ) );
-    return( ret );
-}
-
 /*
  * STATE HANDLING: Read CertificateVerify
  */
@@ -860,20 +571,20 @@
                                         const unsigned char *end )
 {
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
-    size_t cert_req_ctx_len = 0;
+    size_t certificate_request_context_len = 0;
     size_t certificate_list_len = 0;
     const unsigned char *p = buf;
     const unsigned char *certificate_list_end;
 
     MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, 4 );
-    cert_req_ctx_len = p[0];
+    certificate_request_context_len = p[0];
     certificate_list_len = MBEDTLS_GET_UINT24_BE( p, 1 );
     p += 4;
 
     /* In theory, the certificate list can be up to 2^24 Bytes, but we don't
      * support anything beyond 2^16 = 64K.
      */
-    if( ( cert_req_ctx_len != 0 ) ||
+    if( ( certificate_request_context_len != 0 ) ||
         ( certificate_list_len >= 0x10000 ) )
     {
         MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate message" ) );