fixed checks for valid GDB data

Author: thorstendb-ARM

src/views/component-viewer/component-viewer-target-access.ts

@@ -136,8 +136,6 @@ export class ComponentViewerTargetAccess {
         }
     }
 
-
-
     public async evaluateMemory(address: string, length: number, offset: number): Promise<string | undefined> {
         try {
             const args: DebugProtocol.ReadMemoryArguments = {

src/views/component-viewer/scvd-debug-target.ts

@@ -49,6 +49,17 @@ function toUint32(value: number | bigint): number | bigint {
     return value >>> 0;
 }
 
+function isLikelyBase64(data: string): boolean {
+    const trimmed = data.trim();
+    if (trimmed.length === 0 || trimmed.length % 4 === 1) {
+        return false;
+    }
+    if (/[^A-Za-z0-9+/=]/.test(trimmed)) {
+        return false;
+    }
+    return true;
+}
+
 export function gdbNameFor(name: string): string | undefined {
     return REGISTER_GDB_MAP.get(normalize(name));
 }
@@ -234,6 +245,10 @@ export class ScvdDebugTarget {
         if (dataAsString.startsWith('Unable')) {
             return undefined;
         }
+        if (!isLikelyBase64(dataAsString)) {
+            console.error(`ScvdDebugTarget.readMemory: invalid base64 data for address ${address.toString()}`);
+            return undefined;
+        }
         // Convert String data to Uint8Array
         const byteArray = this.decodeGdbData(dataAsString);
 

src/views/component-viewer/test/integration/scvd-debug-target.test.ts

@@ -180,6 +180,12 @@ describe('scvd-debug-target', () => {
         accessMock.evaluateMemory.mockResolvedValue(undefined);
         await expect(target.readMemory(0x0, 3)).resolves.toBeUndefined();
 
+        const errorSpy = jest.spyOn(console, 'error').mockImplementation(() => {});
+        accessMock.evaluateMemory.mockResolvedValue('No active session');
+        await expect(target.readMemory(0x0, 3)).resolves.toBeUndefined();
+        expect(errorSpy).toHaveBeenCalled();
+        errorSpy.mockRestore();
+
         accessMock.evaluateMemory.mockResolvedValue('AQID'); // len 3 vs requested 4
         await expect(target.readMemory(0x0, 4)).resolves.toEqual(new Uint8Array([1, 2, 3]));
     });