changelog: document the enforced check on x509 serial setting
Signed-off-by: Valerio Setti <vsetti@baylibre.com>
diff --git a/ChangeLog.d/improve_x509_cert_writing_serial_number_management.txt b/ChangeLog.d/improve_x509_cert_writing_serial_number_management.txt
new file mode 100644
index 0000000..a85c79b
--- /dev/null
+++ b/ChangeLog.d/improve_x509_cert_writing_serial_number_management.txt
@@ -0,0 +1,5 @@
+Bugfix
+ * mbedtls_x509write_crt_set_serial() now explicitly rejects serial numbers
+ whose binary representation is longer than 20 bytes. This was already
+ forbidden by the standard (RFC5280 - section 4.1.2.2) and now it's being
+ enforced also at code level.