tls13: Add function to search for a supported_versions extension
Move in a dedicated function the search for the
supported_versions extension in a list of
extensions, to be able to use it on server side
as well.
Signed-off-by: Ronald Cron <ronald.cron@arm.com>
diff --git a/library/ssl_misc.h b/library/ssl_misc.h
index 14a3c7e..e136c35 100644
--- a/library/ssl_misc.h
+++ b/library/ssl_misc.h
@@ -2048,6 +2048,32 @@
unsigned char **buf,
size_t *buf_len);
+/**
+ * \brief Detect if a list of extensions contains a supported_versions
+ * extension or not.
+ *
+ * \param[in] ssl SSL context
+ * \param[in] buf Address of the first byte of the extensions vector.
+ * \param[in] end End of the buffer containing the list of extensions.
+ * \param[out] extension_data If the extension is present, address of its first
+ * byte of data, NULL otherwise.
+ * \param[out] extension_data_end If the extension is present, address of the
+ * first byte immediately following the extension
+ * data, NULL otherwise.
+ * \return 0 if the list of extensions does not contain a supported_versions
+ * extension.
+ * \return 1 if the list of extensions contains a supported_versions
+ * extension.
+ * \return A negative value if an error occurred while parsing the
+ * extensions.
+ */
+MBEDTLS_CHECK_RETURN_CRITICAL
+int mbedtls_ssl_tls13_is_supported_versions_ext_present_in_exts(
+ mbedtls_ssl_context *ssl,
+ const unsigned char *buf, const unsigned char *end,
+ const unsigned char **extension_data,
+ const unsigned char **extension_data_end);
+
/*
* Handler of TLS 1.3 server certificate message
*/