2 files changed, 85 insertions, 1 deletions
diff --git a/packages/meshbay-hub/src/meshbay_hub/db/migrations/versions/f8a9b0c1d2e3_node_keys.py b/packages/meshbay-hub/src/meshbay_hub/db/migrations/versions/f8a9b0c1d2e3_node_keys.py
new file mode 100644
index 0000000..b02167b
--- /dev/null
+++ b/packages/meshbay-hub/src/meshbay_hub/db/migrations/versions/f8a9b0c1d2e3_node_keys.py
@@ -0,0 +1,63 @@
+"""several node keys per account: one per machine the person runs a node on
+
+Revision ID: f8a9b0c1d2e3
+Revises: e7f8a9b0c1d2
+"""
+
+import uuid
+from collections.abc import Sequence
+from datetime import UTC, datetime
+
+import sqlalchemy as sa
+from alembic import op
+
+revision: str = "f8a9b0c1d2e3"
+down_revision: str | Sequence[str] | None = "e7f8a9b0c1d2"
+branch_labels: str | Sequence[str] | None = None
+depends_on: str | Sequence[str] | None = None
+
+
+def upgrade() -> None:
+    node_keys = op.create_table(
+        "node_keys",
+        sa.Column("id", sa.String(36), primary_key=True),
+        sa.Column("user_id", sa.String(36), sa.ForeignKey("users.id"), nullable=False),
+        sa.Column("pk_node_ed25519", sa.String(64), nullable=False),
+        sa.Column("linked_at", sa.DateTime(timezone=True)),
+    )
+    op.create_index("uq_node_keys_user_key", "node_keys",
+                    ["user_id", "pk_node_ed25519"], unique=True)
+
+    # The key each account had linked keeps working: it becomes that account's
+    # first row, so no node has to be linked again after the upgrade.
+    conn = op.get_bind()
+    linked = conn.execute(sa.text(
+        "SELECT id, pk_node_ed25519 FROM users WHERE pk_node_ed25519 IS NOT NULL "
+        "AND pk_node_ed25519 <> ''")).fetchall()
+    now = datetime.now(UTC)
+    if linked:
+        op.bulk_insert(node_keys, [
+            {"id": str(uuid.uuid4()), "user_id": uid, "pk_node_ed25519": pk,
+             "linked_at": now}
+            for uid, pk in linked])
+
+    with op.batch_alter_table("users") as batch:
+        batch.drop_column("pk_node_ed25519")
+
+
+def downgrade() -> None:
+    with op.batch_alter_table("users") as batch:
+        batch.add_column(sa.Column("pk_node_ed25519", sa.String(64), nullable=True))
+
+    # One column holds one key: the most recently linked one is kept, which is
+    # the node the account would have had linked last before this revision.
+    conn = op.get_bind()
+    rows = conn.execute(sa.text(
+        "SELECT user_id, pk_node_ed25519 FROM node_keys ORDER BY linked_at")).fetchall()
+    latest = {uid: pk for uid, pk in rows}
+    for uid, pk in latest.items():
+        conn.execute(sa.text("UPDATE users SET pk_node_ed25519 = :pk WHERE id = :uid"),
+                     {"pk": pk, "uid": uid})
+
+    op.drop_index("uq_node_keys_user_key", table_name="node_keys")
+    op.drop_table("node_keys")
diff --git a/packages/meshbay-hub/src/meshbay_hub/db/models.py b/packages/meshbay-hub/src/meshbay_hub/db/models.py
index 7291485..e37a479 100644
--- a/packages/meshbay-hub/src/meshbay_hub/db/models.py
+++ b/packages/meshbay-hub/src/meshbay_hub/db/models.py
@@ -53,7 +53,6 @@ class User(Base):
     # the node does the wrapping, nothing reads a key from this directory. Keys
     # are generated per node and pinned there (meshbay_node/roster.py).
     email_hash:  Mapped[str | None] = mapped_column(String(64), nullable=True)  # HMAC blind index
-    pk_node_ed25519: Mapped[str | None] = mapped_column(String(64), nullable=True)
     hub_id:           Mapped[str] = mapped_column(String(128), nullable=False)
     # user|moderator|admin
     role:             Mapped[str] = mapped_column(String(16), default="user")
@@ -104,6 +103,28 @@ class Node(Base):
     __table_args__ = (Index("ix_nodes_user_id", "user_id"),)
 
 
+class NodeKey(Base):
+    """A node key this account has linked: the key `/v1/nodes/auth` accepts for it.
+
+    One row per machine the person runs a node on. Linking is done from a
+    browser session and nowhere else; a node's own token can neither add nor
+    remove one (`require_user_scope`). Removing the row cuts that node off at
+    once — its socket is closed and the tokens it holds name this key (`nk`),
+    so they stop working — and leaves the account's other nodes alone.
+    """
+
+    __tablename__ = "node_keys"
+
+    id:              Mapped[str] = mapped_column(String(36), primary_key=True, default=_uuid)
+    user_id:         Mapped[str] = mapped_column(ForeignKey("users.id"), nullable=False)
+    pk_node_ed25519: Mapped[str] = mapped_column(String(64), nullable=False)
+    linked_at:       Mapped[datetime] = mapped_column(DateTime(timezone=True), default=_now)
+
+    __table_args__ = (
+        Index("uq_node_keys_user_key", "user_id", "pk_node_ed25519", unique=True),
+    )
+
+
 # ── Groups ────────────────────────────────────────────────────────────────────
 
 class Group(Base):