feat(cli): add new migrate-secret-key command (reanahub#240)

Closes reanahub/reana-server#695

reana_db/cli.py

@@ -21,6 +21,7 @@
 from reana_db.database import init_db
 from reana_db.models import Resource, ResourceType
 from reana_db.utils import (
+    change_key_encrypted_columns,
     update_users_cpu_quota,
     update_users_disk_quota,
     update_workflows_cpu_quota,
@@ -43,6 +44,25 @@ def init():
     click.secho("Database initialised.", fg="green")
 
 
+@cli.command()
+@click.option(
+    "--old-key",
+    required=True,
+    help="Previous key used to encrypt database columns.",
+)
+def migrate_secret_key(old_key):
+    """Change the secret key used to encrypt database columns."""
+    click.echo("Migrating secret key...")
+
+    try:
+        change_key_encrypted_columns(old_key)
+    except Exception:
+        logging.exception("Failed to migrate secret key")
+        sys.exit(1)
+
+    click.echo("Successfully migrated secret key")
+
+
 @cli.group("alembic")
 @click.pass_context
 def alembic_group(ctx):

reana_db/models.py

@@ -51,8 +51,8 @@
 from sqlalchemy_utils.types.encrypted.encrypted_type import AesEngine
 from sqlalchemy.dialects.postgresql import ARRAY
 
+import reana_db.config
 from reana_db.config import (
-    DB_SECRET_KEY,
     DEFAULT_QUOTA_LIMITS,
     DEFAULT_QUOTA_RESOURCES,
     WORKFLOW_TERMINATION_QUOTA_UPDATE_POLICY,
@@ -87,6 +87,15 @@ def generate_uuid():
     return str(uuid.uuid4())
 
 
+def _secret_key():
+    """Secret key used to encrypt databse columns.
+
+    Do not use `DB_SECRET_KEY` directly, as that does not let us change the key
+    at runtime, which is needed when migrating between different keys.
+    """
+    return reana_db.config.DB_SECRET_KEY
+
+
 class QuotaBase:
     """Quota base functionality."""
 
@@ -326,7 +335,7 @@ class UserToken(Base, Timestamp):
 
     id_ = Column(UUIDType, primary_key=True, default=generate_uuid)
     token = Column(
-        EncryptedType(String(length=255), DB_SECRET_KEY, AesEngine, "pkcs5"),
+        EncryptedType(String(length=255), _secret_key, AesEngine, "pkcs5"),
         unique=True,
     )
     status = Column(Enum(UserTokenStatus))

reana_db/utils.py

@@ -612,3 +612,33 @@ def update_workflows_disk_quota() -> None:
     for workflow in workflows:
         store_workflow_disk_quota(workflow)
         timer.count_event()
+
+
+def change_key_encrypted_columns(old_key):
+    """Re-encrypt database columns with new secret key.
+
+    REANA should be already deployed with the new secret key in `REANA_SECRET_KEY`.
+    The old key is needed to decrypt the database and is passed as parameter.
+    """
+    from reana_db.database import Session
+    from reana_db.models import UserToken
+    from reana_db import config
+
+    new_key = config.DB_SECRET_KEY
+
+    # set old key to be able to decrypt columns in database
+    config.DB_SECRET_KEY = old_key
+
+    # read the columns from the database
+    user_tokens = Session.query(UserToken.id_, UserToken.token).all()
+    Session.expunge_all()
+
+    # revert to new key
+    config.DB_SECRET_KEY = new_key
+
+    # write columns to the database to encrypt them with new key
+    for user_token in user_tokens:
+        UserToken.query.filter_by(id_=user_token.id_).update(
+            {"token": user_token.token}
+        )
+    Session.commit()