From b060a3c9e2cb6f400de707ff0785565c006e333e Mon Sep 17 00:00:00 2001
From: Dave Longley <dlongley@digitalbazaar.com>
Date: Wed, 2 Oct 2024 21:15:26 -0400
Subject: [PATCH] Ensure VM ID is a string in `ControllerProofPurpose`.

---
 CHANGELOG.md                           | 6 ++++++
 lib/purposes/ControllerProofPurpose.js | 5 +++++
 2 files changed, 11 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8700bf38..0808b865 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,11 @@
 # jsonld-signatures ChangeLog
 
+## 11.3.1 - 2024-10-dd
+
+### Fixed
+- Ensure verification method ID is a string when checking controller
+  proof purpose.
+
 ## 11.3.0 - 2024-08-01
 
 ### Changed
diff --git a/lib/purposes/ControllerProofPurpose.js b/lib/purposes/ControllerProofPurpose.js
index 67226806..1e002861 100644
--- a/lib/purposes/ControllerProofPurpose.js
+++ b/lib/purposes/ControllerProofPurpose.js
@@ -70,6 +70,11 @@ module.exports = class ControllerProofPurpose extends ProofPurpose {
       }
 
       const {id: verificationId} = verificationMethod;
+      if(typeof verificationId !== 'string') {
+        throw new Error(
+          `Verification method ID "${verificationMethod.id}" ` +
+          'must be a string.');
+      }
       const {term, _termDefinedByDIDContext} = this;
 
       // if no `controller` specified, use verification method's