setup-python/node_modules/http-signature/lib/parser.js

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2019-06-27 08:12:00 +07:00
// Copyright 2012 Joyent, Inc. All rights reserved.
var assert = require('assert-plus');
var util = require('util');
var utils = require('./utils');
///--- Globals
var HASH_ALGOS = utils.HASH_ALGOS;
var PK_ALGOS = utils.PK_ALGOS;
var HttpSignatureError = utils.HttpSignatureError;
var InvalidAlgorithmError = utils.InvalidAlgorithmError;
var validateAlgorithm = utils.validateAlgorithm;
var State = {
New: 0,
Params: 1
};
var ParamsState = {
Name: 0,
Quote: 1,
Value: 2,
Comma: 3
};
///--- Specific Errors
function ExpiredRequestError(message) {
HttpSignatureError.call(this, message, ExpiredRequestError);
}
util.inherits(ExpiredRequestError, HttpSignatureError);
function InvalidHeaderError(message) {
HttpSignatureError.call(this, message, InvalidHeaderError);
}
util.inherits(InvalidHeaderError, HttpSignatureError);
function InvalidParamsError(message) {
HttpSignatureError.call(this, message, InvalidParamsError);
}
util.inherits(InvalidParamsError, HttpSignatureError);
function MissingHeaderError(message) {
HttpSignatureError.call(this, message, MissingHeaderError);
}
util.inherits(MissingHeaderError, HttpSignatureError);
function StrictParsingError(message) {
HttpSignatureError.call(this, message, StrictParsingError);
}
util.inherits(StrictParsingError, HttpSignatureError);
///--- Exported API
module.exports = {
/**
* Parses the 'Authorization' header out of an http.ServerRequest object.
*
* Note that this API will fully validate the Authorization header, and throw
* on any error. It will not however check the signature, or the keyId format
* as those are specific to your environment. You can use the options object
* to pass in extra constraints.
*
* As a response object you can expect this:
*
* {
* "scheme": "Signature",
* "params": {
* "keyId": "foo",
* "algorithm": "rsa-sha256",
* "headers": [
* "date" or "x-date",
* "digest"
* ],
* "signature": "base64"
* },
* "signingString": "ready to be passed to crypto.verify()"
* }
*
* @param {Object} request an http.ServerRequest.
* @param {Object} options an optional options object with:
* - clockSkew: allowed clock skew in seconds (default 300).
* - headers: required header names (def: date or x-date)
* - algorithms: algorithms to support (default: all).
* - strict: should enforce latest spec parsing
* (default: false).
* @return {Object} parsed out object (see above).
* @throws {TypeError} on invalid input.
* @throws {InvalidHeaderError} on an invalid Authorization header error.
* @throws {InvalidParamsError} if the params in the scheme are invalid.
* @throws {MissingHeaderError} if the params indicate a header not present,
* either in the request headers from the params,
* or not in the params from a required header
* in options.
* @throws {StrictParsingError} if old attributes are used in strict parsing
* mode.
* @throws {ExpiredRequestError} if the value of date or x-date exceeds skew.
*/
parseRequest: function parseRequest(request, options) {
assert.object(request, 'request');
assert.object(request.headers, 'request.headers');
if (options === undefined) {
options = {};
}
if (options.headers === undefined) {
options.headers = [request.headers['x-date'] ? 'x-date' : 'date'];
}
assert.object(options, 'options');
assert.arrayOfString(options.headers, 'options.headers');
assert.optionalFinite(options.clockSkew, 'options.clockSkew');
var authzHeaderName = options.authorizationHeaderName || 'authorization';
if (!request.headers[authzHeaderName]) {
throw new MissingHeaderError('no ' + authzHeaderName + ' header ' +
'present in the request');
}
options.clockSkew = options.clockSkew || 300;
var i = 0;
var state = State.New;
var substate = ParamsState.Name;
var tmpName = '';
var tmpValue = '';
var parsed = {
scheme: '',
params: {},
signingString: ''
};
var authz = request.headers[authzHeaderName];
for (i = 0; i < authz.length; i++) {
var c = authz.charAt(i);
switch (Number(state)) {
case State.New:
if (c !== ' ') parsed.scheme += c;
else state = State.Params;
break;
case State.Params:
switch (Number(substate)) {
case ParamsState.Name:
var code = c.charCodeAt(0);
// restricted name of A-Z / a-z
if ((code >= 0x41 && code <= 0x5a) || // A-Z
(code >= 0x61 && code <= 0x7a)) { // a-z
tmpName += c;
} else if (c === '=') {
if (tmpName.length === 0)
throw new InvalidHeaderError('bad param format');
substate = ParamsState.Quote;
} else {
throw new InvalidHeaderError('bad param format');
}
break;
case ParamsState.Quote:
if (c === '"') {
tmpValue = '';
substate = ParamsState.Value;
} else {
throw new InvalidHeaderError('bad param format');
}
break;
case ParamsState.Value:
if (c === '"') {
parsed.params[tmpName] = tmpValue;
substate = ParamsState.Comma;
} else {
tmpValue += c;
}
break;
case ParamsState.Comma:
if (c === ',') {
tmpName = '';
substate = ParamsState.Name;
} else {
throw new InvalidHeaderError('bad param format');
}
break;
default:
throw new Error('Invalid substate');
}
break;
default:
throw new Error('Invalid substate');
}
}
if (!parsed.params.headers || parsed.params.headers === '') {
if (request.headers['x-date']) {
parsed.params.headers = ['x-date'];
} else {
parsed.params.headers = ['date'];
}
} else {
parsed.params.headers = parsed.params.headers.split(' ');
}
// Minimally validate the parsed object
if (!parsed.scheme || parsed.scheme !== 'Signature')
throw new InvalidHeaderError('scheme was not "Signature"');
if (!parsed.params.keyId)
throw new InvalidHeaderError('keyId was not specified');
if (!parsed.params.algorithm)
throw new InvalidHeaderError('algorithm was not specified');
if (!parsed.params.signature)
throw new InvalidHeaderError('signature was not specified');
// Check the algorithm against the official list
parsed.params.algorithm = parsed.params.algorithm.toLowerCase();
try {
validateAlgorithm(parsed.params.algorithm);
} catch (e) {
if (e instanceof InvalidAlgorithmError)
throw (new InvalidParamsError(parsed.params.algorithm + ' is not ' +
'supported'));
else
throw (e);
}
// Build the signingString
for (i = 0; i < parsed.params.headers.length; i++) {
var h = parsed.params.headers[i].toLowerCase();
parsed.params.headers[i] = h;
if (h === 'request-line') {
if (!options.strict) {
/*
* We allow headers from the older spec drafts if strict parsing isn't
* specified in options.
*/
parsed.signingString +=
request.method + ' ' + request.url + ' HTTP/' + request.httpVersion;
} else {
/* Strict parsing doesn't allow older draft headers. */
throw (new StrictParsingError('request-line is not a valid header ' +
'with strict parsing enabled.'));
}
} else if (h === '(request-target)') {
parsed.signingString +=
'(request-target): ' + request.method.toLowerCase() + ' ' +
request.url;
} else {
var value = request.headers[h];
if (value === undefined)
throw new MissingHeaderError(h + ' was not in the request');
parsed.signingString += h + ': ' + value;
}
if ((i + 1) < parsed.params.headers.length)
parsed.signingString += '\n';
}
// Check against the constraints
var date;
if (request.headers.date || request.headers['x-date']) {
if (request.headers['x-date']) {
date = new Date(request.headers['x-date']);
} else {
date = new Date(request.headers.date);
}
var now = new Date();
var skew = Math.abs(now.getTime() - date.getTime());
if (skew > options.clockSkew * 1000) {
throw new ExpiredRequestError('clock skew of ' +
(skew / 1000) +
's was greater than ' +
options.clockSkew + 's');
}
}
options.headers.forEach(function (hdr) {
// Remember that we already checked any headers in the params
// were in the request, so if this passes we're good.
if (parsed.params.headers.indexOf(hdr.toLowerCase()) < 0)
throw new MissingHeaderError(hdr + ' was not a signed header');
});
if (options.algorithms) {
if (options.algorithms.indexOf(parsed.params.algorithm) === -1)
throw new InvalidParamsError(parsed.params.algorithm +
' is not a supported algorithm');
}
parsed.algorithm = parsed.params.algorithm.toUpperCase();
parsed.keyId = parsed.params.keyId;
return parsed;
}
};