Add some more x509_verify tests
- trust chain of depth 0
- invalid signature
- trust chain of depth 2
- multiple trusted CA's
diff --git a/tests/data_files/test-int-ca.key b/tests/data_files/test-int-ca.key
new file mode 100644
index 0000000..9d0e234
--- /dev/null
+++ b/tests/data_files/test-int-ca.key
@@ -0,0 +1,16 @@
+-----BEGIN PRIVATE KEY-----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+-----END PRIVATE KEY-----