fix: support multiple SSHPubKey records per user

There was one blazing issue with the previous implementation regardless
of the multiple records: we were generating fingerprints by storing
the key into a file and reading it with ssh-keygen. This is absolutely
terrible and was not meant to be left around (it was forgotten, my bad).

Took this opportunity to clean up a few things:
- simplify pubkey validation
- centralize things a bit better

Signed-off-by: Kevin Morris <kevr@0cost.org>

aurweb/users/update.py

@@ -2,7 +2,8 @@ from typing import Any, Dict
 
 from fastapi import Request
 
-from aurweb import cookies, db, models, time
+from aurweb import cookies, db, models, time, util
+from aurweb.models import SSHPubKey
 from aurweb.models.ssh_pub_key import get_fingerprint
 from aurweb.util import strtobool
 
@@ -52,32 +53,35 @@ def timezone(TZ: str = str(),
         context["language"] = TZ
 
 
-def ssh_pubkey(PK: str = str(),
-               user: models.User = None,
-               **kwargs) -> None:
-    # If a PK is given, compare it against the target user's PK.
-    if PK:
-        # Get the second token in the public key, which is the actual key.
-        pubkey = PK.strip().rstrip()
-        parts = pubkey.split(" ")
-        if len(parts) == 3:
-            # Remove the host part.
-            pubkey = parts[0] + " " + parts[1]
-        fingerprint = get_fingerprint(pubkey)
-        if not user.ssh_pub_key:
-            # No public key exists, create one.
-            with db.begin():
-                db.create(models.SSHPubKey, UserID=user.ID,
-                          PubKey=pubkey, Fingerprint=fingerprint)
-        elif user.ssh_pub_key.PubKey != pubkey:
-            # A public key already exists, update it.
-            with db.begin():
-                user.ssh_pub_key.PubKey = pubkey
-                user.ssh_pub_key.Fingerprint = fingerprint
-    elif user.ssh_pub_key:
-        # Else, if the user has a public key already, delete it.
+def ssh_pubkey(PK: str = str(), user: models.User = None, **kwargs) -> None:
+    if not PK:
+        # If no pubkey is provided, wipe out any pubkeys the user
+        # has and return out early.
         with db.begin():
-            db.delete(user.ssh_pub_key)
+            db.delete_all(user.ssh_pub_keys)
+        return
+
+    # Otherwise, parse ssh keys and their fprints out of PK.
+    keys = util.parse_ssh_keys(PK.strip())
+    fprints = [get_fingerprint(" ".join(k)) for k in keys]
+
+    with db.begin():
+        # Delete any existing keys we can't find.
+        to_remove = user.ssh_pub_keys.filter(
+            ~SSHPubKey.Fingerprint.in_(fprints))
+        db.delete_all(to_remove)
+
+        # For each key, if it does not yet exist, create it.
+        for i, full_key in enumerate(keys):
+            prefix, key = full_key
+            exists = user.ssh_pub_keys.filter(
+                SSHPubKey.Fingerprint == fprints[i]
+            ).exists()
+            if not db.query(exists).scalar():
+                # No public key exists, create one.
+                db.create(models.SSHPubKey, UserID=user.ID,
+                          PubKey=" ".join([prefix, key]),
+                          Fingerprint=fprints[i])
 
 
 def account_type(T: int = None,

aurweb/users/validate.py

@@ -107,14 +107,16 @@ def invalid_pgp_key(K: str = str(), **kwargs) -> None:
 
 def invalid_ssh_pubkey(PK: str = str(), user: models.User = None,
                        _: l10n.Translator = None, **kwargs) -> None:
-    if PK:
-        invalid_exc = ValidationError(["The SSH public key is invalid."])
-        if not util.valid_ssh_pubkey(PK):
-            raise invalid_exc
+    if not PK:
+        return
 
-        fingerprint = get_fingerprint(PK.strip().rstrip())
-        if not fingerprint:
-            raise invalid_exc
+    try:
+        keys = util.parse_ssh_keys(PK.strip())
+    except ValueError as exc:
+        raise ValidationError([str(exc)])
+
+    for prefix, key in keys:
+        fingerprint = get_fingerprint(f"{prefix} {key}")
 
         exists = db.query(models.SSHPubKey).filter(
             and_(models.SSHPubKey.UserID != user.ID,