Current File : //usr/lib/node_modules/npm/node_modules/http-signature/lib/signer.js
// Copyright 2012 Joyent, Inc. All rights reserved.
var assert = require('assert-plus');
var crypto = require('crypto');
var http = require('http');
var util = require('util');
var sshpk = require('sshpk');
var jsprim = require('jsprim');
var utils = require('./utils');
var sprintf = require('util').format;
var HASH_ALGOS = utils.HASH_ALGOS;
var PK_ALGOS = utils.PK_ALGOS;
var InvalidAlgorithmError = utils.InvalidAlgorithmError;
var HttpSignatureError = utils.HttpSignatureError;
var validateAlgorithm = utils.validateAlgorithm;
///--- Globals
var AUTHZ_FMT =
'Signature keyId="%s",algorithm="%s",headers="%s",signature="%s"';
///--- Specific Errors
function MissingHeaderError(message) {
HttpSignatureError.call(this, message, MissingHeaderError);
}
util.inherits(MissingHeaderError, HttpSignatureError);
function StrictParsingError(message) {
HttpSignatureError.call(this, message, StrictParsingError);
}
util.inherits(StrictParsingError, HttpSignatureError);
/* See createSigner() */
function RequestSigner(options) {
assert.object(options, 'options');
var alg = [];
if (options.algorithm !== undefined) {
assert.string(options.algorithm, 'options.algorithm');
alg = validateAlgorithm(options.algorithm);
}
this.rs_alg = alg;
/*
* RequestSigners come in two varieties: ones with an rs_signFunc, and ones
* with an rs_signer.
*
* rs_signFunc-based RequestSigners have to build up their entire signing
* string within the rs_lines array and give it to rs_signFunc as a single
* concat'd blob. rs_signer-based RequestSigners can add a line at a time to
* their signing state by using rs_signer.update(), thus only needing to
* buffer the hash function state and one line at a time.
*/
if (options.sign !== undefined) {
assert.func(options.sign, 'options.sign');
this.rs_signFunc = options.sign;
} else if (alg[0] === 'hmac' && options.key !== undefined) {
assert.string(options.keyId, 'options.keyId');
this.rs_keyId = options.keyId;
if (typeof (options.key) !== 'string' && !Buffer.isBuffer(options.key))
throw (new TypeError('options.key for HMAC must be a string or Buffer'));
/*
* Make an rs_signer for HMACs, not a rs_signFunc -- HMACs digest their
* data in chunks rather than requiring it all to be given in one go
* at the end, so they are more similar to signers than signFuncs.
*/
this.rs_signer = crypto.createHmac(alg[1].toUpperCase(), options.key);
this.rs_signer.sign = function () {
var digest = this.digest('base64');
return ({
hashAlgorithm: alg[1],
toString: function () { return (digest); }
});
};
} else if (options.key !== undefined) {
var key = options.key;
if (typeof (key) === 'string' || Buffer.isBuffer(key))
key = sshpk.parsePrivateKey(key);
assert.ok(sshpk.PrivateKey.isPrivateKey(key, [1, 2]),
'options.key must be a sshpk.PrivateKey');
this.rs_key = key;
assert.string(options.keyId, 'options.keyId');
this.rs_keyId = options.keyId;
if (!PK_ALGOS[key.type]) {
throw (new InvalidAlgorithmError(key.type.toUpperCase() + ' type ' +
'keys are not supported'));
}
if (alg[0] !== undefined && key.type !== alg[0]) {
throw (new InvalidAlgorithmError('options.key must be a ' +
alg[0].toUpperCase() + ' key, was given a ' +
key.type.toUpperCase() + ' key instead'));
}
this.rs_signer = key.createSign(alg[1]);
} else {
throw (new TypeError('options.sign (func) or options.key is required'));
}
this.rs_headers = [];
this.rs_lines = [];
}
/**
* Adds a header to be signed, with its value, into this signer.
*
* @param {String} header
* @param {String} value
* @return {String} value written
*/
RequestSigner.prototype.writeHeader = function (header, value) {
assert.string(header, 'header');
header = header.toLowerCase();
assert.string(value, 'value');
this.rs_headers.push(header);
if (this.rs_signFunc) {
this.rs_lines.push(header + ': ' + value);
} else {
var line = header + ': ' + value;
if (this.rs_headers.length > 0)
line = '\n' + line;
this.rs_signer.update(line);
}
return (value);
};
/**
* Adds a default Date header, returning its value.
*
* @return {String}
*/
RequestSigner.prototype.writeDateHeader = function () {
return (this.writeHeader('date', jsprim.rfc1123(new Date())));
};
/**
* Adds the request target line to be signed.
*
* @param {String} method, HTTP method (e.g. 'get', 'post', 'put')
* @param {String} path
*/
RequestSigner.prototype.writeTarget = function (method, path) {
assert.string(method, 'method');
assert.string(path, 'path');
method = method.toLowerCase();
this.writeHeader('(request-target)', method + ' ' + path);
};
/**
* Calculate the value for the Authorization header on this request
* asynchronously.
*
* @param {Func} callback (err, authz)
*/
RequestSigner.prototype.sign = function (cb) {
assert.func(cb, 'callback');
if (this.rs_headers.length < 1)
throw (new Error('At least one header must be signed'));
var alg, authz;
if (this.rs_signFunc) {
var data = this.rs_lines.join('\n');
var self = this;
this.rs_signFunc(data, function (err, sig) {
if (err) {
cb(err);
return;
}
try {
assert.object(sig, 'signature');
assert.string(sig.keyId, 'signature.keyId');
assert.string(sig.algorithm, 'signature.algorithm');
assert.string(sig.signature, 'signature.signature');
alg = validateAlgorithm(sig.algorithm);
authz = sprintf(AUTHZ_FMT,
sig.keyId,
sig.algorithm,
self.rs_headers.join(' '),
sig.signature);
} catch (e) {
cb(e);
return;
}
cb(null, authz);
});
} else {
try {
var sigObj = this.rs_signer.sign();
} catch (e) {
cb(e);
return;
}
alg = (this.rs_alg[0] || this.rs_key.type) + '-' + sigObj.hashAlgorithm;
var signature = sigObj.toString();
authz = sprintf(AUTHZ_FMT,
this.rs_keyId,
alg,
this.rs_headers.join(' '),
signature);
cb(null, authz);
}
};
///--- Exported API
module.exports = {
/**
* Identifies whether a given object is a request signer or not.
*
* @param {Object} object, the object to identify
* @returns {Boolean}
*/
isSigner: function (obj) {
if (typeof (obj) === 'object' && obj instanceof RequestSigner)
return (true);
return (false);
},
/**
* Creates a request signer, used to asynchronously build a signature
* for a request (does not have to be an http.ClientRequest).
*
* @param {Object} options, either:
* - {String} keyId
* - {String|Buffer} key
* - {String} algorithm (optional, required for HMAC)
* or:
* - {Func} sign (data, cb)
* @return {RequestSigner}
*/
createSigner: function createSigner(options) {
return (new RequestSigner(options));
},
/**
* Adds an 'Authorization' header to an http.ClientRequest object.
*
* Note that this API will add a Date header if it's not already set. Any
* other headers in the options.headers array MUST be present, or this
* will throw.
*
* You shouldn't need to check the return type; it's just there if you want
* to be pedantic.
*
* The optional flag indicates whether parsing should use strict enforcement
* of the version draft-cavage-http-signatures-04 of the spec or beyond.
* The default is to be loose and support
* older versions for compatibility.
*
* @param {Object} request an instance of http.ClientRequest.
* @param {Object} options signing parameters object:
* - {String} keyId required.
* - {String} key required (either a PEM or HMAC key).
* - {Array} headers optional; defaults to ['date'].
* - {String} algorithm optional (unless key is HMAC);
* default is the same as the sshpk default
* signing algorithm for the type of key given
* - {String} httpVersion optional; defaults to '1.1'.
* - {Boolean} strict optional; defaults to 'false'.
* @return {Boolean} true if Authorization (and optionally Date) were added.
* @throws {TypeError} on bad parameter types (input).
* @throws {InvalidAlgorithmError} if algorithm was bad or incompatible with
* the given key.
* @throws {sshpk.KeyParseError} if key was bad.
* @throws {MissingHeaderError} if a header to be signed was specified but
* was not present.
*/
signRequest: function signRequest(request, options) {
assert.object(request, 'request');
assert.object(options, 'options');
assert.optionalString(options.algorithm, 'options.algorithm');
assert.string(options.keyId, 'options.keyId');
assert.optionalArrayOfString(options.headers, 'options.headers');
assert.optionalString(options.httpVersion, 'options.httpVersion');
if (!request.getHeader('Date'))
request.setHeader('Date', jsprim.rfc1123(new Date()));
if (!options.headers)
options.headers = ['date'];
if (!options.httpVersion)
options.httpVersion = '1.1';
var alg = [];
if (options.algorithm) {
options.algorithm = options.algorithm.toLowerCase();
alg = validateAlgorithm(options.algorithm);
}
var i;
var stringToSign = '';
for (i = 0; i < options.headers.length; i++) {
if (typeof (options.headers[i]) !== 'string')
throw new TypeError('options.headers must be an array of Strings');
var h = options.headers[i].toLowerCase();
if (h === 'request-line') {
if (!options.strict) {
/**
* We allow headers from the older spec drafts if strict parsing isn't
* specified in options.
*/
stringToSign +=
request.method + ' ' + request.path + ' HTTP/' +
options.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)') {
stringToSign +=
'(request-target): ' + request.method.toLowerCase() + ' ' +
request.path;
} else {
var value = request.getHeader(h);
if (value === undefined || value === '') {
throw new MissingHeaderError(h + ' was not in the request');
}
stringToSign += h + ': ' + value;
}
if ((i + 1) < options.headers.length)
stringToSign += '\n';
}
/* This is just for unit tests. */
if (request.hasOwnProperty('_stringToSign')) {
request._stringToSign = stringToSign;
}
var signature;
if (alg[0] === 'hmac') {
if (typeof (options.key) !== 'string' && !Buffer.isBuffer(options.key))
throw (new TypeError('options.key must be a string or Buffer'));
var hmac = crypto.createHmac(alg[1].toUpperCase(), options.key);
hmac.update(stringToSign);
signature = hmac.digest('base64');
} else {
var key = options.key;
if (typeof (key) === 'string' || Buffer.isBuffer(key))
key = sshpk.parsePrivateKey(options.key);
assert.ok(sshpk.PrivateKey.isPrivateKey(key, [1, 2]),
'options.key must be a sshpk.PrivateKey');
if (!PK_ALGOS[key.type]) {
throw (new InvalidAlgorithmError(key.type.toUpperCase() + ' type ' +
'keys are not supported'));
}
if (alg[0] !== undefined && key.type !== alg[0]) {
throw (new InvalidAlgorithmError('options.key must be a ' +
alg[0].toUpperCase() + ' key, was given a ' +
key.type.toUpperCase() + ' key instead'));
}
var signer = key.createSign(alg[1]);
signer.update(stringToSign);
var sigObj = signer.sign();
if (!HASH_ALGOS[sigObj.hashAlgorithm]) {
throw (new InvalidAlgorithmError(sigObj.hashAlgorithm.toUpperCase() +
' is not a supported hash algorithm'));
}
options.algorithm = key.type + '-' + sigObj.hashAlgorithm;
signature = sigObj.toString();
assert.notStrictEqual(signature, '', 'empty signature produced');
}
var authzHeaderName = options.authorizationHeaderName || 'Authorization';
request.setHeader(authzHeaderName, sprintf(AUTHZ_FMT,
options.keyId,
options.algorithm,
options.headers.join(' '),
signature));
return true;
}
};
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