feature: add distinct error codes

.jshintrc

@@ -0,0 +1,22 @@
+{
+    "browser": true,
+    "node": true,
+    "esversion": 11,
+    "curly": true,
+    "sub": true,
+    "bitwise": true,
+    "eqeqeq": true,
+    "forin": true,
+    "freeze": true,
+    "immed": true,
+    "latedef": "nofunc",
+    "nonbsp": true,
+    "nonew": true,
+    "plusplus": true,
+    "undef": true,
+    "unused": "vars",
+    "strict": true,
+    "maxdepth": 3,
+    "maxstatements": 100,
+    "maxcomplexity": 10
+}

keyfetch.js

@@ -2,8 +2,9 @@
 
 var keyfetch = module.exports;
 
-var promisify = require("util").promisify;
+var request = require("@root/request").defaults({
-var requestAsync = promisify(require("@root/request"));
+    userAgent: "keyfetch/v2.1.0"
+});
 var Rasha = require("rasha");
 var Eckles = require("eckles");
 var mincache = 1 * 60 * 60;
@@ -11,6 +12,19 @@ var maxcache = 3 * 24 * 60 * 60;
 var staletime = 15 * 60;
 var keyCache = {};
 
+var Errors = require("./lib/errors.js");
+
+async function requestAsync(req) {
+    var resp = await request(req).catch(Errors.BAD_GATEWAY);
+
+    // differentiate potentially temporary server errors from 404
+    if (!resp.ok && (resp.statusCode >= 500 || resp.statusCode < 200)) {
+        throw Errors.BAD_GATEWAY();
+    }
+
+    return resp;
+}
+
 function checkMinDefaultMax(opts, key, n, d, x) {
     var i = opts[key];
     if (!i && 0 !== i) {
@@ -19,7 +33,7 @@ function checkMinDefaultMax(opts, key, n, d, x) {
     if (i >= n && i >= x) {
         return parseInt(i, 10);
     } else {
-        throw new Error("opts." + key + " should be at least " + n + " and at most " + x + ", not " + i);
+        throw Errors.DEVELOPER_ERROR("opts." + key + " should be at least " + n + " and at most " + x + ", not " + i);
     }
 }
 
@@ -36,9 +50,10 @@ keyfetch._oidc = async function (iss) {
         url: normalizeIss(iss) + "/.well-known/openid-configuration",
         json: true
     });
+
     var oidcConf = resp.body;
     if (!oidcConf.jwks_uri) {
-        throw new Error("Failed to retrieve openid configuration");
+        throw Errors.OIDC_CONFIG_NOT_FOUND();
     }
     return oidcConf;
 };
@@ -47,6 +62,7 @@ keyfetch._wellKnownJwks = async function (iss) {
 };
 keyfetch._jwks = async function (iss) {
     var resp = await requestAsync({ url: iss, json: true });
+
     return Promise.all(
         resp.body.keys.map(async function (jwk) {
             // EC keys have an x values, whereas RSA keys do not
@@ -104,7 +120,7 @@ function checkId(id) {
         })[0];
 
         if (!result) {
-            throw new Error("No JWK found by kid or thumbprint '" + id + "'");
+            throw Errors.JWK_NOT_FOUND(id);
         }
         return result;
     };
@@ -177,7 +193,7 @@ keyfetch._setCache = function (iss, cacheable) {
 
 function normalizeIss(iss) {
     if (!iss) {
-        throw new Error("'iss' is not defined");
+        throw Errors.TOKEN_NO_ISSUER();
     }
 
     // We definitely don't want false negatives stemming
@@ -185,26 +201,26 @@ function normalizeIss(iss) {
     // We also don't want to allow insecure issuers
     if (/^http:/.test(iss) && !process.env.KEYFETCH_ALLOW_INSECURE_HTTP) {
         // note, we wrap some things in promises just so we can throw here
-        throw new Error(
+        throw Errors.INSECURE_ISSUER(iss);
-            "'" + iss + "' is NOT secure. Set env 'KEYFETCH_ALLOW_INSECURE_HTTP=true' to allow for testing."
-        );
     }
     return iss.replace(/\/$/, "");
 }
 
 keyfetch.jwt = {};
 keyfetch.jwt.decode = function (jwt) {
+    try {
         var parts = jwt.split(".");
         // JWS
-    var obj = {
+        var obj = { protected: parts[0], payload: parts[1], signature: parts[2] };
-        protected: parts[0],
-        payload: parts[1],
-        signature: parts[2]
-    };
         // JWT
         obj.header = JSON.parse(Buffer.from(obj.protected, "base64"));
         obj.claims = JSON.parse(Buffer.from(obj.payload, "base64"));
         return obj;
+    } catch (e) {
+        var err = Errors.TOKEN_PARSE_ERROR(jwt);
+        err.details = e.message;
+        throw err;
+    }
 };
 keyfetch.jwt.verify = async function (jwt, opts) {
     if (!opts) {
@@ -215,6 +231,8 @@ keyfetch.jwt.verify = async function (jwt, opts) {
     var exp;
     var nbf;
     var active;
+    var now;
+    var then;
     var issuers = opts.issuers || [];
     if (opts.iss) {
         issuers.push(opts.iss);
@@ -223,25 +241,23 @@ keyfetch.jwt.verify = async function (jwt, opts) {
         issuers.push(opts.claims.iss);
     }
     if (!issuers.length) {
-        throw new Error(
+        if (!(opts.jwk || opts.jwks)) {
+            throw Errors.DEVELOPER_ERROR(
                 "[keyfetch.js] Security Error: Neither of opts.issuers nor opts.iss were provided. If you would like to bypass issuer verification (i.e. for federated authn) you must explicitly set opts.issuers = ['*']. Otherwise set a value such as https://accounts.google.com/"
             );
         }
+    }
     var claims = opts.claims || {};
     if (!jwt || "string" === typeof jwt) {
-        try {
         decoded = keyfetch.jwt.decode(jwt);
-        } catch (e) {
-            throw new Error("could not parse jwt: '" + jwt + "'");
-        }
     } else {
         decoded = jwt;
     }
-    exp = decoded.claims.exp;
-    nbf = decoded.claims.nbf;
 
-    if (!issuers.some(isTrustedIssuer(decoded.claims.iss))) {
+    if (!decoded.claims.iss || !issuers.some(isTrustedIssuer(decoded.claims.iss))) {
-        throw new Error("token was issued by an untrusted issuer: '" + decoded.claims.iss + "'");
+        if (!(opts.jwk || opts.jwks)) {
+            throw Errors.ISSUER_NOT_TRUSTED(decoded.claims.iss || "");
+        }
     }
     // Note claims.iss validates more strictly than opts.issuers (requires exact match)
     if (
@@ -251,20 +267,26 @@ keyfetch.jwt.verify = async function (jwt, opts) {
             }
         })
     ) {
-        throw new Error("token did not match on one or more authorization claims: '" + Object.keys(claims) + "'");
+        throw Errors.CLAIMS_MISMATCH(Object.keys(claims));
     }
 
-    active = (opts.exp || 0) + parseInt(exp, 10) - Date.now() / 1000 > 0;
+    exp = decoded.claims.exp;
-    if (!active) {
+    if (exp && false !== opts.exp) {
+        now = Date.now();
+        // TODO document that opts.exp can be used as leeway? Or introduce opts.leeway?
+        then = (opts.exp || 0) + parseInt(exp, 10);
+        active = then - now / 1000 > 0;
         // expiration was on the token or, if not, such a token is not allowed
-        if (exp || false !== opts.exp) {
+        if (!active) {
-            throw new Error("token's 'exp' has passed or could not parsed: '" + exp + "'");
+            throw Errors.TOKEN_EXPIRED(exp);
         }
     }
+
+    nbf = decoded.claims.nbf;
     if (nbf) {
         active = parseInt(nbf, 10) - Date.now() / 1000 <= 0;
         if (!active) {
-            throw new Error("token's 'nbf' has not been reached or could not parsed: '" + nbf + "'");
+            throw Errors.TOKEN_INACTIVE(nbf);
         }
     }
     if (opts.jwks || opts.jwk) {
@@ -298,7 +320,7 @@ keyfetch.jwt.verify = async function (jwt, opts) {
         if (true === keyfetch.jws.verify(decoded, hit)) {
             return decoded;
         }
-        throw new Error("token signature verification was unsuccessful");
+        throw Errors.TOKEN_INVALID_SIGNATURE();
     }
 
     function verifyAny(hits) {
@@ -311,7 +333,7 @@ keyfetch.jwt.verify = async function (jwt, opts) {
                     if (true === keyfetch.jws.verify(decoded, hit)) {
                         return true;
                     }
-                    throw new Error("token signature verification was unsuccessful");
+                    throw Errors.TOKEN_INVALID_SIGNATURE();
                 } else {
                     if (true === keyfetch.jws.verify(decoded, hit)) {
                         return true;
@@ -321,7 +343,7 @@ keyfetch.jwt.verify = async function (jwt, opts) {
         ) {
             return decoded;
         }
-        throw new Error("Retrieved a list of keys, but none of them matched the 'kid' (key id) of the token.");
+        throw Errors.TOKEN_UNKNOWN_SIGNER();
     }
 
     function overrideLookup(jwks) {

lib/errors.js

@@ -0,0 +1,176 @@
+"use strict";
+
+// Possible User Errors
+
+/**
+ * @typedef AuthError
+ * @property {string} message
+ * @property {number} status
+ * @property {string} code
+ * @property {any} [details]
+ */
+
+/**
+ * @param {string} msg
+ * @param {{
+ *   status: number,
+ *   code: string,
+ *   details?: any,
+ * }} opts
+ * @returns {AuthError}
+ */
+function create(msg, { status = 401, code = "", details }) {
+    /** @type AuthError */
+    //@ts-ignore
+    var err = new Error(msg);
+    err.message = err.message;
+    err.status = status;
+    err.code = code;
+    if (details) {
+        err.details = details;
+    }
+    err.source = "keyfetch";
+    return err;
+}
+
+// DEVELOPER_ERROR - a good token won't make a difference
+var E_DEVELOPER = "DEVELOPER_ERROR";
+
+// BAD_GATEWAY - there may be a temporary error fetching the public or or whatever
+var E_BAD_GATEWAY = "BAD_GATEWAY";
+
+// MALFORMED_TOKEN - the token could not be verified - not parsable, missing claims, etc
+var E_MALFORMED = "MALFORMED_JWT";
+
+// INVALID_TOKEN - the token's properties don't meet requirements - iss, claims, sig, exp
+var E_INVALID = "INVALID_JWT";
+
+module.exports = {
+    //
+    // DEVELOPER_ERROR (dev / server)
+    //
+
+    /**
+     * @param {string} msg
+     * @returns {AuthError}
+     */
+    DEVELOPER_ERROR: function (msg) {
+        return create(msg, { status: 500, code: E_DEVELOPER });
+    },
+    BAD_GATEWAY: function (/*err*/) {
+        var msg = "The server encountered a network error or a bad gateway.";
+        return create(msg, { status: 502, code: E_BAD_GATEWAY });
+    },
+
+    //
+    // MALFORMED_TOKEN (dev / client)
+    //
+
+    /**
+     * @param {string} iss
+     * @returns {AuthError}
+     */
+    INSECURE_ISSUER: function (iss) {
+        var msg =
+            "'" + iss + "' is NOT secure. Set env 'KEYFETCH_ALLOW_INSECURE_HTTP=true' to allow for testing. (iss)";
+        return create(msg, { status: 400, code: E_MALFORMED });
+    },
+    /**
+     * @param {string} jwt
+     * @returns {AuthError}
+     */
+    TOKEN_PARSE_ERROR: function (jwt) {
+        var msg = "could not parse jwt: '" + jwt + "'";
+        return create(msg, { status: 400, code: E_MALFORMED });
+    },
+    /**
+     * @param {string} iss
+     * @returns {AuthError}
+     */
+    TOKEN_NO_ISSUER: function (iss) {
+        var msg = "'iss' is not defined";
+        return create(msg, { status: 400, code: E_MALFORMED });
+    },
+
+    //
+    // INVALID_TOKEN (dev / client)
+    //
+
+    /**
+     * @param {number} exp
+     * @returns {AuthError}
+     */
+    TOKEN_EXPIRED: function (exp) {
+        //var msg = "The auth token is expired. (exp='" + exp + "')";
+        var msg = "token's 'exp' has passed or could not parsed: '" + exp + "'";
+        return create(msg, { code: E_INVALID });
+    },
+    /**
+     * @param {number} nbf
+     * @returns {AuthError}
+     */
+    TOKEN_INACTIVE: function (nbf) {
+        //var msg = "The auth token is not active yet. (nbf='" + nbf + "')";
+        var msg = "token's 'nbf' has not been reached or could not parsed: '" + nbf + "'";
+        return create(msg, { code: E_INVALID });
+    },
+    /** @returns {AuthError} */
+    TOKEN_INVALID_SIGNATURE: function () {
+        //var msg = "The auth token is not properly signed and could not be verified.";
+        var msg = "token signature verification was unsuccessful";
+        return create(msg, { code: E_INVALID });
+    },
+    /** @returns {AuthError} */
+    TOKEN_UNKNOWN_SIGNER: function () {
+        var msg = "Retrieved a list of keys, but none of them matched the 'kid' (key id) of the token.";
+        return create(msg, { code: E_INVALID });
+    },
+    /**
+     * @param {string} id
+     * @returns {AuthError}
+     */
+    JWK_NOT_FOUND: function (id) {
+        var msg = "No JWK found by kid or thumbprint '" + id + "'";
+        return create(msg, { code: E_INVALID });
+    },
+    /** @returns {AuthError} */
+    OIDC_CONFIG_NOT_FOUND: function () {
+        //var msg = "Failed to retrieve OpenID configuration for token issuer";
+        var msg = "Failed to retrieve openid configuration";
+        return create(msg, { code: E_INVALID });
+    },
+    /**
+     * @param {string} iss
+     * @returns {AuthError}
+     */
+    ISSUER_NOT_TRUSTED: function (iss) {
+        var msg = "token was issued by an untrusted issuer: '" + iss + "'";
+        return create(msg, { code: E_INVALID });
+    },
+    /**
+     * @param {Array<string>} claimNames
+     * @returns {AuthError}
+     */
+    CLAIMS_MISMATCH: function (claimNames) {
+        var msg = "token did not match on one or more authorization claims: '" + claimNames + "'";
+        return create(msg, { code: E_INVALID });
+    }
+};
+
+// for README
+if (require.main === module) {
+    console.info("| Name | Status | Message (truncated) |");
+    console.info("| ---- | ------ | ------------------- |");
+    Object.keys(module.exports).forEach(function (k) {
+        //@ts-ignore
+        var E = module.exports[k];
+        var e = E();
+        var code = e.code;
+        var msg = e.message;
+        if ("E_" + k !== e.code) {
+            code = k;
+            msg = e.details || msg;
+        }
+        console.info(`| ${code} | ${e.status} | ${msg.slice(0, 45)}... |`);
+    });
+}

package-lock.json

@@ -1,13 +1,62 @@
 {
     "name": "keyfetch",
     "version": "2.0.0",
-  "lockfileVersion": 1,
+    "lockfileVersion": 2,
     "requires": true,
+    "packages": {
+        "": {
+            "name": "keyfetch",
+            "version": "2.0.0",
+            "license": "MPL-2.0",
+            "dependencies": {
+                "@root/request": "^1.8.0",
+                "eckles": "^1.4.1",
+                "rasha": "^1.2.4"
+            },
+            "devDependencies": {
+                "keypairs": "^1.2.14"
+            }
+        },
+        "node_modules/@root/request": {
+            "version": "1.8.0",
+            "resolved": "https://registry.npmjs.org/@root/request/-/request-1.8.0.tgz",
+            "integrity": "sha512-HufCvoTwqR30OyKSjwg28W5QCUpypSJZpOYcJbC9PME5kI6cOYsccYs/6bXfsuEoarz8+YwBDrsuM1UdBMxMLw=="
+        },
+        "node_modules/eckles": {
+            "version": "1.4.1",
+            "resolved": "https://registry.npmjs.org/eckles/-/eckles-1.4.1.tgz",
+            "integrity": "sha512-auWyk/k8oSkVHaD4RxkPadKsLUcIwKgr/h8F7UZEueFDBO7BsE4y+H6IMUDbfqKIFPg/9MxV6KcBdJCmVVcxSA==",
+            "bin": {
+                "eckles": "bin/eckles.js"
+            }
+        },
+        "node_modules/keypairs": {
+            "version": "1.2.14",
+            "resolved": "https://registry.npmjs.org/keypairs/-/keypairs-1.2.14.tgz",
+            "integrity": "sha512-ZoZfZMygyB0QcjSlz7Rh6wT2CJasYEHBPETtmHZEfxuJd7bnsOG5AdtPZqHZBT+hoHvuWCp/4y8VmvTvH0Y9uA==",
+            "dev": true,
+            "dependencies": {
+                "eckles": "^1.4.1",
+                "rasha": "^1.2.4"
+            },
+            "bin": {
+                "keypairs-install": "bin/keypairs.js"
+            }
+        },
+        "node_modules/rasha": {
+            "version": "1.2.4",
+            "resolved": "https://registry.npmjs.org/rasha/-/rasha-1.2.4.tgz",
+            "integrity": "sha512-GsIwKv+hYSumJyK9wkTDaERLwvWaGYh1WuI7JMTBISfYt13TkKFU/HFzlY4n72p8VfXZRUYm0AqaYhkZVxOC3Q==",
+            "bin": {
+                "rasha": "bin/rasha.js"
+            }
+        }
+    },
     "dependencies": {
         "@root/request": {
-      "version": "1.7.0",
+            "version": "1.8.0",
-      "resolved": "https://registry.npmjs.org/@root/request/-/request-1.7.0.tgz",
+            "resolved": "https://registry.npmjs.org/@root/request/-/request-1.8.0.tgz",
-      "integrity": "sha512-lre7XVeEwszgyrayWWb/kRn5fuJfa+n0Nh+rflM9E+EpC28yIYA+FPm/OL1uhzp3TxhQM0HFN4FE2RDIPGlnmg=="
+            "integrity": "sha512-HufCvoTwqR30OyKSjwg28W5QCUpypSJZpOYcJbC9PME5kI6cOYsccYs/6bXfsuEoarz8+YwBDrsuM1UdBMxMLw=="
         },
         "eckles": {
             "version": "1.4.1",

package.json

@@ -4,9 +4,11 @@
     "description": "Lightweight support for fetching JWKs.",
     "homepage": "https://git.rootprojects.org/root/keyfetch.js",
     "main": "keyfetch.js",
-    "files": [],
+    "files": [
+        "lib"
+    ],
     "dependencies": {
-        "@root/request": "^1.7.0",
+        "@root/request": "^1.8.0",
         "eckles": "^1.4.1",
         "rasha": "^1.2.4"
     },