Check-in [5d6a50ef48]
Overview
Comment:Added SSH agent support
Downloads: Tarball | ZIP archive | SQL archive
Timelines: family | ancestors | descendants | both | trunk
Files: files | file ages | folders
SHA1: 5d6a50ef4881fe38baa504f04eb4d7353692d8bd
User & Date: rkeene on 2019-01-31 07:16:21
Other Links: manifest | tags
Context
2019-01-31
07:23
Improved SSH agent check-in: 43f92f8f98 user: rkeene tags: trunk
07:16
Added SSH agent support check-in: 5d6a50ef48 user: rkeene tags: trunk
07:15
Added SHA512 support and support for returning a promise when signing check-in: a5d56f2277 user: rkeene tags: trunk
Changes

Modified build/chrome/Makefile from [2b4e0751d3] to [388b08b05b].

28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
ifeq (,${NACL_SDK_ROOT})
$(error "Please set NACL_SDK_ROOT")
endif
export NACL_SDK_ROOT

all: cackey.zip

cackey.zip: $(CACKEY_EXECUTABLES) cackey.nmf manifest.json cackey.js google-pcsc.js pin.html pin.js pin-icon.png icon.png ui.html ui.js jsrsasign.js
	rm -f cackey.zip
	zip cackey.zip.new $^
	mv cackey.zip.new cackey.zip

cackey.bc: cackey-chrome-pkcs11.o cackey-chrome-plugin.o lib/libcackey.a lib/libpcsc.a lib/libz.a
	$(CXX) $(CXXFLAGS) $(LDFLAGS) -o cackey.bc.new cackey-chrome-pkcs11.o cackey-chrome-plugin.o $(LIBS)
	mv cackey.bc.new cackey.bc







|







28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
ifeq (,${NACL_SDK_ROOT})
$(error "Please set NACL_SDK_ROOT")
endif
export NACL_SDK_ROOT

all: cackey.zip

cackey.zip: $(CACKEY_EXECUTABLES) cackey.nmf manifest.json cackey.js ssh-agent.js google-pcsc.js pin.html pin.js pin-icon.png icon.png ui.html ui.js jsrsasign.js
	rm -f cackey.zip
	zip cackey.zip.new $^
	mv cackey.zip.new cackey.zip

cackey.bc: cackey-chrome-pkcs11.o cackey-chrome-plugin.o lib/libcackey.a lib/libpcsc.a lib/libz.a
	$(CXX) $(CXXFLAGS) $(LDFLAGS) -o cackey.bc.new cackey-chrome-pkcs11.o cackey-chrome-plugin.o $(LIBS)
	mv cackey.bc.new cackey.bc

Modified build/chrome/manifest.json.in from [3e4f620248] to [46508e25a5].

10
11
12
13
14
15
16


17
18
19
20
21
22
23
24
25
26
27
		"128": "icon.png"
	},

	"app": {
		"background": {
			"scripts": [
				"google-pcsc.js",


				"cackey.js"
			],
			"persistent": false
		}
	},

	"permissions": [
		"certificateProvider",
		"alwaysOnTopWindows"
	]
}







>
>











10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
		"128": "icon.png"
	},

	"app": {
		"background": {
			"scripts": [
				"google-pcsc.js",
				"jsrsasign.js",
				"ssh-agent.js",
				"cackey.js"
			],
			"persistent": false
		}
	},

	"permissions": [
		"certificateProvider",
		"alwaysOnTopWindows"
	]
}

Added build/chrome/ssh-agent.js version [d68e90b355].



































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
/*
 * CACKey SSH Agent for ChromeOS
 */

cackeySSHAgentApprovedApps = [
	"pnhechapfaindjhompbnflcldabbghjo"
];

/*
 * SSH Element Encoding/Decoding
 */
function cackeySSHAgentEncodeInt(uint32) {
	var result;

	result = [
		(uint32 >> 24) & 0xff,
		(uint32 >> 16) & 0xff,
		(uint32 >>  8) & 0xff,
		 uint32        & 0xff
	];

	return(result);
}

function cackeySSHAgentDecodeInt(input) {
	var result;

	result = 0;
	result |= (input[0] << 24);
	result |= (input[1] << 16);
	result |= (input[2] << 8);
	result |=  input[3];

	return({
		value: result,
		output: input.slice(4)
	});
}

function cackeySSHAgentEncodeBigInt(bigInt) {
	var result = [];

	switch (typeof(bigInt)) {
		case "number":
			while (bigInt) {
				result.push(bigInt & 0xff);
				bigInt = bigInt >> 8;
			}
			result.reverse();
			break;
		case "object":
			result = [];
			new Uint8Array(bigInt.toByteArray()).forEach(function(e) {
				result.push(e);
			});
			break;
	}

	result = cackeySSHAgentEncodeLV(result);

	return(result);
}

function cackeySSHAgentEncodeLV(input) {
	var result;

	result = cackeySSHAgentEncodeInt(input.length);
	result = result.concat(input);

	return(result);
}

function cackeySSHAgentDecodeLV(input) {
	var result, info;

	info = cackeySSHAgentDecodeInt(input);
	if (info.value >= input.length) {
		throw(new Error("Invalid data"));
	}

	input = info.output;

	result = input.slice(0, info.value);

	return({
		value: result,
		output: input.slice(info.value)
	});
}

function cackeySSHAgentEncodeTLV(tag, array) {
	var result;

	result = [];

	result.push(tag & 0xff);

	result = result.concat(cackeySSHAgentEncodeLV(array));

	return(result);
}

function cackeySSHAgentEncodeToUTF8Array(str) {
	var utf8 = [];

	if (typeof(str) === "string") {
		str = str.split("").map(function(c) {
			return(c.charCodeAt(0));
		});
	}

	for (var i = 0; i < str.length; i++) {
		var charcode = str[i];

		if (charcode < 0x80) {
			utf8.push(charcode);
		} else if (charcode < 0x800) {
			utf8.push(0xc0 | (charcode >> 6), 
			          0x80 | (charcode & 0x3f));
		} else if (charcode < 0xd800 || charcode >= 0xe000) {
			utf8.push(0xe0 | (charcode >> 12), 
			          0x80 | ((charcode >> 6) & 0x3f), 
			          0x80 | (charcode & 0x3f));
		} else {
			// surrogate pair
			i++;
			// UTF-16 encodes 0x10000-0x10FFFF by
			// subtracting 0x10000 and splitting the
			// 20 bits of 0x0-0xFFFFF into two halves
			charcode = 0x10000 + (((charcode & 0x3ff) << 10)
			           | (str[i] & 0x3ff));

			utf8.push(0xf0 | (charcode >>18), 
			          0x80 | ((charcode >> 12) & 0x3f), 
			          0x80 | ((charcode >> 6) & 0x3f), 
			          0x80 | (charcode & 0x3f));
		}
	}

	return utf8;
}

function cackeySSHAgentEncodeString(string) {
	var result;

	result = cackeySSHAgentEncodeLV(cackeySSHAgentEncodeToUTF8Array(string));

	return(result);
}

function cackeySSHAgentEncodeBinaryToHex(binaryString) {
	var buffer;

	switch (typeof(binaryString)) {
		case "string":
			buffer = binaryString.split("").map(function(c) {
				return(c.charCodeAt(0).toString(16).padStart(2, '0'));
			}).join("");
			break;
		default:
			buffer = [];
			new Uint8Array(binaryString).map(function(c) {
				buffer.push(c.toString(16).padStart(2, '0'));
			});
			buffer = buffer.join("");
			break;
	}

	return(buffer);
}

function cackeySSHAgentEncodeCertToKeyAndID(cert) {
	var result = null, resultKey = null;
	var certObj;
	var publicKey;

	certObj = new X509;
	if (!certObj) {
		return(result);
	}

	certObj.readCertHex(cackeySSHAgentEncodeBinaryToHex(cert));

	publicKey = certObj.getPublicKey();

	switch (publicKey.type) {
		case "RSA":
			resultKey = cackeySSHAgentEncodeString("ssh-rsa");
			resultKey = resultKey.concat(cackeySSHAgentEncodeBigInt(publicKey.e));
			resultKey = resultKey.concat(cackeySSHAgentEncodeBigInt(publicKey.n));
			break;
		default:
			console.log("[cackeySSH] Unsupported public key type:", publicKey.type, "-- ignoring.");
	}

	if (resultKey) {
		result = {
			id: certObj.getSubjectString(),
			key: resultKey
		};
	}

	return(result);
}

/*
 * Command Handlers
 */
async function cackeySSHAgentCommandRequestIdentity(request) {
	var response;
	var certs = [];
	var keys = [];

	/*
	 * Get a list of certificates
	 */
	certs = await cackeyListCertificates();

	/*
	 * Convert each certificate to an SSH key blob
	 */
	certs.forEach(function(cert) {
		var key;

		key = cackeySSHAgentEncodeCertToKeyAndID(cert.certificate);

		if (key) {
			keys.push(key);
		}
	});

	/*
	 * Encode response
	 */
	response = [];

	response.push(cackeySSHAgentMessage.SSH_AGENT_IDENTITIES_ANSWER);
	response = response.concat(cackeySSHAgentEncodeInt(keys.length));
	keys.forEach(function(key) {
		response = response.concat(cackeySSHAgentEncodeLV(key.key));
		response = response.concat(cackeySSHAgentEncodeString("CACKey: " + key.id));
	});

	return(response);
}

async function cackeySSHAgentCommandSignRequest(request) {
	var keyInfo, data, flags;
	var certs, certToUse;
	var hashMethod, signedData, signedDataHeader, signRequest;
	var response;
	var flagMeaning = {
		SSH_AGENT_RSA_SHA2_256: 2,
		SSH_AGENT_RSA_SHA2_512: 4
	};

	/*
	 * Strip off the command
	 */
	request = request.slice(1);

	/*
	 * Get certificate to sign using
	 */
	keyInfo = cackeySSHAgentDecodeLV(request);
	request = keyInfo.output;
	keyInfo = keyInfo.value;

	/*
	 * Get the data to sign
	 */
	data = cackeySSHAgentDecodeLV(request);
	request = data.output;
	data = data.value;

	/*
	 * Get the flags
	 */
	flags = cackeySSHAgentDecodeInt(request);
	request = flags.output;
	flags = flags.value;

	/*
	 * Find the certificate that matches the requested key
	 */
	certs = await cackeyListCertificates();
	certToUse = null;
	certs.forEach(function(cert) {
		var key;

		key = cackeySSHAgentEncodeCertToKeyAndID(cert.certificate);

		if (key.key.join() == keyInfo.join()) {
			certToUse = cert;
		}
	});

	/*
	 * If no certificate is found, return an error
	 */
	if (!certToUse) {
		console.info("[cackeySSH] Unable to find a certificate to match the requested key:", keyInfo);

		return(null);
	}

	/*
	 * Perform hashing of the data as specified by the flags
	 */
	if ((flags & flagMeaning.SSH_AGENT_RSA_SHA2_512) == flagMeaning.SSH_AGENT_RSA_SHA2_512) {
		hashMethod = "SHA512";
		data = await crypto.subtle.digest("SHA-512", new Uint8Array(data));
	} else if ((flags & flagMeaning.SSH_AGENT_RSA_SHA2_256) == flagMeaning.SSH_AGENT_RSA_SHA2_256) {
		hashMethod = "SHA256";
		data = await crypto.subtle.digest("SHA-256", new Uint8Array(data));
	} else if (flags == 1) {
		hashMethod = "SHA1";
		data = await crypto.subtle.digest("SHA-1", new Uint8Array(data));
	} else {
		console.info("[cackeySSH] Sign request with flags set to", flags, "which is unsupported, failing the request.");

		return(null);
	}

	/*
	 * Sign the data
	 */
	signRequest = {
		hash: hashMethod,
		digest: new Uint8Array(data)
	};
	signedData = await cackeySignMessage(signRequest);
	signedData = Array.from(new Uint8Array(signedData));

	/*
	 * Encode signature
	 */
	switch (hashMethod) {
		case "SHA1":
			signedDataHeader = cackeySSHAgentEncodeString("ssh-rsa");
			break;
		case "SHA256":
			signedDataHeader = cackeySSHAgentEncodeString("rsa-sha2-256");
			break;
		case "SHA512":
			signedDataHeader = cackeySSHAgentEncodeString("rsa-sha2-512");
			break;
		default:
			signedDataHeader = [];
			break;
	}
	signedData = signedDataHeader.concat(cackeySSHAgentEncodeLV(signedData));

	/*
	 * Encode response
	 */
	response = [];

	response.push(cackeySSHAgentMessage.SSH_AGENT_SIGN_RESPONSE);
	response = response.concat(cackeySSHAgentEncodeLV(signedData));

	return(response);
}

/*
 * Session handling
 */
async function cackeySSHAgentHandleMessage(socket, request) {
	var sshRequestID, sshRequest, response, sshResponse;
	var sshHandlerError;

	if (!request.type || request.type !== "auth-agent@openssh.com") {
		return;
	}

	if (!request.data || request.data.length < 1) {
		return;
	}

	sshRequestID = request.data[0];
	sshRequest = {};
	if (sshRequestID < cackeySSHAgentCommands.length) {
		sshRequest = cackeySSHAgentCommands[sshRequestID];
	}

	response = null;
	if (!sshRequest.name) {
		console.log("[cackeySSH] Unsupported request: ", request, "; from: ", socket.sender.id);
	} else {
		if (goog.DEBUG) {
			console.log("[cackeySSH] Request: ", sshRequest.name, "; from: ", socket.sender.id);
		}

		try {
			response = await sshRequest.handler(request.data);
		} catch (sshHandlerError) {
			response = null;

			console.error("[cackeySSH] Request:", sshRequest.name, "(", request, ") ERROR:", sshHandlerError);
		}
	}

	if (!response) {
		response = [cackeySSHAgentMessage.SSH_AGENT_FAILURE];
	}

	sshResponse = {
		type: "auth-agent@openssh.com",
		data: response
	};

	if (goog.DEBUG) {
		console.log("[cackeySSH] Response: ", sshResponse);
	}

	socket.postMessage(sshResponse);

	return;
}

function cackeySSHAgentAcceptConnection(socket) {
	if (!socket) {
		return;
	}

	/*
	 * Only accept connections from approved apps
	 */
	if (!socket.sender || !socket.sender.id || !cackeySSHAgentApprovedApps.includes(socket.sender.id)) {
		console.log("[cackeySSH] Disconnecting unapproved app: ", socket.sender);

		socket.disconnect();

		return;
	}

	console.log("[cackeySSH] Accepted connection from: ", socket.sender.id);
	socket.onMessage.addListener(function(request) {
		cackeySSHAgentHandleMessage(socket, request);
	});
}

function cackeySSHAgentInit() {
	chrome.runtime.onConnectExternal.addListener(cackeySSHAgentAcceptConnection);
}

function cackeySSHAgentUninit() {
	chrome.runtime.onConnectExternal.removeListener(cackeySSHAgentAcceptConnection);
}

cackeySSHAgentCommands = [
	{ /* 0: Not implemented */ },
	{ /* 1: Not implemented */ },
	{ /* 2: Not implemented */ },
	{ /* 3: Not implemented */ },
	{ /* 4: Not implemented */ },
	{ /* 5: Not implemented */ },
	{ /* 6: Not implemented */ },
	{ /* 7: Not implemented */ },
	{ /* 8: Not implemented */ },
	{ /* 9: Not implemented */ },
	{ /* 10: Not implemented */ },
	{
		name: "requestIdentities",
		handler: cackeySSHAgentCommandRequestIdentity
	},
	{ /* 12: Not implemented */ },
	{
		name: "signRequest",
		handler: cackeySSHAgentCommandSignRequest
	},
	{ /* 14: Not implemented */ },
	{ /* 15: Not implemented */ },
	{ /* 16: Not implemented */ },
	{ /* 17: Not implemented */ },
	{ /* 18: Not implemented */ },
	{ /* 19: Not implemented */ },
	{ /* 20: Not implemented */ },
	{ /* 21: Not implemented */ },
	{ /* 22: Not implemented */ },
	{ /* 23: Not implemented */ },
	{ /* 24: Not implemented */ },
	{ /* 25: Not implemented */ },
	{ /* 26: Not implemented */ },
	{ /* 27: Not implemented */ },
	{ /* 28: Not implemented */ }
];

cackeySSHAgentMessage = {
	SSH_AGENT_FAILURE: 5,
	SSH_AGENT_SUCCESS: 6,
	SSH_AGENT_EXTENSION_FAILURE: 28,
	SSH_AGENT_IDENTITIES_ANSWER: 12,
	SSH_AGENT_SIGN_RESPONSE: 14
};

cackeySSHAgentInit();