Azure "JsonWebTokenError: invalid algorithm"

从包含 jwt.verify 的后端 API 路径开始，并将其在 Azure Static Web Apps 中的部署行为与本地模拟器进行比较。检查已部署的令牌、Microsoft identity jwks_uri 返回的证书以及配置的 RS256 算法；当确定 Azure-only invalid-algorithm 错误的原因，并且验证能够正常工作或该限制已被记录时，issue 即完成。

Description

Only occurs when deployed to Azure cloud, local Azure Static Web Apps emulator is all ok.

Azure Static Web App (SWA) with integrated API. One of the step at backend API is to validate the Bearer Token with public key submitted in request headers:

const jwt = require("jsonwebtoken");  // v 8.5.1
async function getMSPublicKey(misc)   // misc contains kid and tenantId, confirmed in F12 request header
{
    var vurl = "https://login.microsoftonline.com/" + misc.tenantId + "/v2.0/.well-known/openid-configuration";
    const x1 = await fetch(vurl);
    const x2 = await x1.json();
    const x3 = await fetch(x2.jwks_uri);
    const k = await x3.json();
    return pkey = k.keys.find( k => k.kid === misc.kid).x5c[0];  // public key in the entry matching kid
}

var vmisc = JSON.parse(ac.req.headers["misc"]);
var publickey = "-----BEGIN CERTIFICATE-----\n" + await getMSPublicKey(vmisc) + "\n-----END CERTIFICATE-----";

// next line is reported in AppTraces, Message = JsonWebTokenError: invalid algorithm
var payload = jwt.verify(theToken, publickey, { algorithms: ['RS256'] });
// theToken is validated ok at jwt.io

Environment

Azure Static Web Application

• jsonwebtoken: v 8.5.1
• azurefunctions: 3.5.2.0, node v 14.16.0
• VSC Version: 1.63.1 (system setup)
  Commit: fe719cd3e5825bf14e14182fddeb88ee8daf044f
  Date: 2021-12-14T02:13:54.292Z
  Electron: 13.5.2
  Chromium: 91.0.4472.164
  Node.js: 14.16.0
  V8: 9.1.269.39-electron.0
  OS: Windows_NT x64 10.0.19044