feat: cwt support for ProofOfPossessionBuilder

Author: nklomp

packages/client/lib/AccessTokenClient.ts

@@ -259,7 +259,9 @@ export class AccessTokenClient {
     accessTokenRequest: AccessTokenRequest,
     opts?: { headers?: Record<string, string> },
   ): Promise<OpenIDResponse<AccessTokenResponse, DPoPResponseParams>> {
-    return await formPost(requestTokenURL, convertJsonToURI(accessTokenRequest, { mode: JsonURIMode.X_FORM_WWW_URLENCODED }), {
+    const body = convertJsonToURI(accessTokenRequest, { mode: JsonURIMode.X_FORM_WWW_URLENCODED })
+    LOG.info(`Token request to ${requestTokenURL}: ${body}`)
+    return await formPost(requestTokenURL, body, {
       customHeaders: opts?.headers ? opts.headers : undefined,
     })
   }

packages/client/lib/OpenID4VCIClient.ts

@@ -354,11 +354,12 @@ export class OpenID4VCIClient {
       })
 
       if (response.errorBody) {
-        logger.debug(`Access token error:\r\n${JSON.stringify(response.errorBody)}`)
+        const errorDetail = typeof response.errorBody === 'object' ? JSON.stringify(response.errorBody) : String(response.errorBody)
+        logger.error(`Access token error response (status ${response.origResponse.status}):\r\n${errorDetail}`)
         throw Error(
           `Retrieving an access token from ${this._state.endpointMetadata?.token_endpoint} for issuer ${this.getIssuer()} failed with status: ${
             response.origResponse.status
-          }`,
+          }. Response: ${errorDetail}`,
         )
       } else if (!response.successBody) {
         logger.debug(`Access token error. No success body`)