[SRI Message Signatures] Render the signature base when relevant.

If a signature-mismatch issue is rendered, ensure that the signature
base is displayed as well to give developers half a chance of diagnosing
their error.

This is the devtools side of a two-sided patch:

1. (Chromium) https://crrev.com/c/6354969
2. (Devtools) https://crrev.com/c/6357210 [You are here]

Bug: 381044049
Change-Id: Ie163e8e83824aed33eb4d6ccc61319a688c25267
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/6357210
Reviewed-by: Simon Zünd <[email protected]>
Reviewed-by: Danil Somsikov <[email protected]>
Commit-Queue: Mike West <[email protected]>

Author: mikewest

front_end/models/issues_manager/SRIMessageSignatureIssue.ts

@@ -114,7 +114,9 @@ export class SRIMessageSignatureIssue extends Issue {
   constructor(issueDetails: Protocol.Audits.SRIMessageSignatureIssueDetails, issuesModel: SDK.IssuesModel.IssuesModel) {
     super(
         {
-          code: getIssueCode(issueDetails),
+          // Append the signature base to the enum's code in order to prevent
+          // distinct error details from coalescing in the issues panel.
+          code: getIssueCode(issueDetails) + issueDetails.signatureBase,
           umaCode: [
             Protocol.Audits.InspectorIssueCode.SRIMessageSignatureIssue,
             issueDetails.error,
@@ -144,6 +146,9 @@ export class SRIMessageSignatureIssue extends Issue {
     if (!description) {
       return null;
     }
+    if (this.#issueDetails.signatureBase !== '') {
+      description.substitutions = new Map([['PLACEHOLDER_signatureBase', () => this.#issueDetails.signatureBase]]);
+    }
     return resolveLazyDescription(description);
   }
 

front_end/models/issues_manager/descriptions/sriValidationFailedSignatureMismatch.md

@@ -3,3 +3,9 @@
 The public key specified in the [`signature-input`](signatureInputHeader)
 header's [`keyid` parameter](signatureParameters) does not match the signature
 specified in the [`signature`](signatureHeader) header. Verification failed.
+
+The following is the signature base over which the verification attempt was made:
+
+```
+{PLACEHOLDER_signatureBase}
+```