add a SAN to the certificatebuilder example (#3353)
Evidently users copy/paste these examples so adding a SAN here will help
people screw up less. Fixes #3314
diff --git a/docs/x509/reference.rst b/docs/x509/reference.rst
index 68e1f73..1823231 100644
--- a/docs/x509/reference.rst
+++ b/docs/x509/reference.rst
@@ -601,6 +601,12 @@
>>> builder = builder.serial_number(x509.random_serial_number())
>>> builder = builder.public_key(public_key)
>>> builder = builder.add_extension(
+ ... x509.SubjectAlternativeName(
+ ... [x509.DNSName(u'cryptography.io')]
+ ... ),
+ ... critical=False
+ ... )
+ >>> builder = builder.add_extension(
... x509.BasicConstraints(ca=False, path_length=None), critical=True,
... )
>>> certificate = builder.sign(