Fix basic WWW-Authenticate header issue

Author: bwateratmsft

packages/vscode-docker-registries/CHANGELOG.md

@@ -1,6 +1,7 @@
 ## 0.4.2 - 16 April 2026
 ### Fixed
 * Fixed an issue where some requests would fail. [#354](https://github.com/microsoft/vscode-docker-extensibility/issues/354)
+* Fixed incorrect handling of basic auth `WWW-Authenticate` headers. [#355](https://github.com/microsoft/vscode-docker-extensibility/issues/355)
 
 ## 0.4.1 - 14 October 2025
 ### Fixed

packages/vscode-docker-registries/src/auth/BasicOAuthProvider.ts

@@ -74,13 +74,16 @@ export class BasicOAuthProvider extends BasicAuthProvider implements Authenticat
 
         const match = wwwAuthenticateHeaderRegex.exec(wwwAuthenticateHeader);
 
-        if (!match?.groups?.realm || !match?.groups?.service || !match?.groups?.scope) {
+        if (match?.groups?.realm && match?.groups?.service && match?.groups?.scope) {
+            this.oAuthEndpoint = match.groups.realm;
+            this.oAuthService = match.groups.service;
+            this.defaultScopes = match.groups.scope.split(' ');
+        } else if (!/Basic\s+/i.test(wwwAuthenticateHeader)) {
             throw new Error(vscode.l10n.t('Unable to parse WWW-Authenticate header: "{0}"', wwwAuthenticateHeader));
         }
+        // For Basic challenges, oAuthEndpoint/oAuthService remain undefined,
+        // so getSession will use Basic auth directly.
 
-        this.oAuthEndpoint = match.groups.realm;
-        this.oAuthService = match.groups.service;
-        this.defaultScopes = match.groups.scope.split(' ');
         this._didFallback = true;
     }