Migrate cert related tests to newer pkey module

- Merge them but also break them up. It's complicated.
- Move cert files into _support
- Related comments in the source as some of this is non-intuitive

1 files changed, 50 insertions, 1 deletions

diff --git a/tests/pkey.py b/tests/pkey.py
index 9c8fe8fc..98193165 100644
--- a/tests/pkey.py
+++ b/tests/pkey.py
@@ -1,7 +1,7 @@
 from pytest import raises
 
 from cryptography.hazmat.primitives.asymmetric.ed448 import Ed448PrivateKey
-from paramiko import PKey, UnknownKeyType, RSAKey
+from paramiko import PKey, Ed25519Key, RSAKey, UnknownKeyType, Message
 
 from ._util import _support
 
@@ -36,3 +36,52 @@ class PKey_:
             # a Python file is not a private key!
             with raises(ValueError):
                 PKey.from_path(__file__)
+
+
+    class load_certificate:
+        def rsa_public_cert_blobs(self):
+            # Data to test signing with (arbitrary)
+            data = b"ice weasels"
+            # Load key w/o cert at first (so avoiding .from_path)
+            key = RSAKey.from_private_key_file(_support("rsa.key"))
+            assert key.public_blob is None
+            # Sign regular-style (using, arbitrarily, SHA2)
+            msg = key.sign_ssh_data(data, "rsa-sha2-256")
+            msg.rewind()
+            assert "rsa-sha2-256" == msg.get_text()
+            signed = msg.get_binary()  # for comparison later
+
+            # Load cert and inspect its internals
+            key.load_certificate(_support("rsa.key-cert.pub"))
+            assert key.public_blob is not None
+            assert key.public_blob.key_type == "ssh-rsa-cert-v01@openssh.com"
+            assert key.public_blob.comment == "test_rsa.key.pub"
+            msg = Message(key.public_blob.key_blob)
+            # cert type
+            assert msg.get_text() == "ssh-rsa-cert-v01@openssh.com"
+            # nonce
+            msg.get_string()
+            # public numbers
+            assert msg.get_mpint() == key.public_numbers.e
+            assert msg.get_mpint() == key.public_numbers.n
+            # serial number
+            assert msg.get_int64() == 1234
+            # TODO: whoever wrote the OG tests didn't care about the remaining
+            # fields from
+            # https://github.com/openssh/openssh-portable/blob/master/PROTOCOL.certkeys
+            # so neither do I, for now...
+
+            # Sign cert-style (still SHA256 - so this actually does almost
+            # exactly the same thing under the hood as the previous sign)
+            msg = key.sign_ssh_data(data, "rsa-sha2-256-cert-v01@openssh.com")
+            msg.rewind()
+            assert "rsa-sha2-256" == msg.get_text()
+            assert signed == msg.get_binary()  # same signature as above
+            msg.rewind()
+            assert key.verify_ssh_sig(b"ice weasels", msg)  # our data verified
+
+        def loading_cert_of_different_type_from_key_raises_ValueError(self):
+            edkey = Ed25519Key.from_private_key_file(_support("ed25519.key"))
+            err = "PublicBlob type ssh-rsa-cert-v01@openssh.com incompatible with key type ssh-ed25519"  # noqa
+            with raises(ValueError, match=err):
+                edkey.load_certificate(_support("rsa.key-cert.pub"))