Fix generated test X.509 certificates. (#917)

From RFC 5280, section 4.1.2.9:

   [Extensions] MUST only appear if the version is 3 (Section 4.1.2.1).
   If present, this field is a SEQUENCE of one or more certificate
   extensions.  The format and content of certificate extensions in the
   Internet PKI are defined in Section 4.2.

X509 objects default to v1, so the test certs need a set_version(2) call. (Note
v3 is encoded as 2.)

Author: davidben

tests/test_crypto.py

@@ -1729,6 +1729,9 @@ def test_digest(self):
 
     def _extcert(self, pkey, extensions):
         cert = X509()
+        # Certificates with extensions must be X.509v3, which is encoded with a
+        # version of two.
+        cert.set_version(2)
         cert.set_pubkey(pkey)
         cert.get_subject().commonName = "Unit Tests"
         cert.get_issuer().commonName = "Unit Tests"

tests/test_ssl.py

@@ -199,6 +199,7 @@ def _create_certificate_chain():
     cakey = PKey()
     cakey.generate_key(TYPE_RSA, 1024)
     cacert = X509()
+    cacert.set_version(2)
     cacert.get_subject().commonName = "Authority Certificate"
     cacert.set_issuer(cacert.get_subject())
     cacert.set_pubkey(cakey)
@@ -212,6 +213,7 @@ def _create_certificate_chain():
     ikey = PKey()
     ikey.generate_key(TYPE_RSA, 1024)
     icert = X509()
+    icert.set_version(2)
     icert.get_subject().commonName = "Intermediate Certificate"
     icert.set_issuer(cacert.get_subject())
     icert.set_pubkey(ikey)
@@ -225,6 +227,7 @@ def _create_certificate_chain():
     skey = PKey()
     skey.generate_key(TYPE_RSA, 1024)
     scert = X509()
+    scert.set_version(2)
     scert.get_subject().commonName = "Server Certificate"
     scert.set_issuer(icert.get_subject())
     scert.set_pubkey(skey)