summaryrefslogtreecommitdiffstats
blob: a702cde08468e6741994902d66221c7693a30aff (plain)
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
/*
 * Copyright (c) 2015 Isode Limited.
 * All rights reserved.
 * See the COPYING file for more information.
 */

#include <Swiften/TLS/SecureTransport/SecureTransportContext.h>

#include <boost/type_traits.hpp>
#include <boost/numeric/conversion/cast.hpp>

#include <Swiften/Base/Algorithm.h>
#include <Swiften/Base/Log.h>
#include <Swiften/TLS/SecureTransport/SecureTransportCertificate.h>
#include <Swiften/TLS/PKCS12Certificate.h>
#include <Swiften/TLS/CertificateWithKey.h>

#include <Cocoa/Cocoa.h>

#import <Security/SecCertificate.h>
#import <Security/SecImportExport.h>

namespace {
	typedef boost::remove_pointer<CFArrayRef>::type CFArray;
	typedef boost::remove_pointer<SecTrustRef>::type SecTrust;
}

template <typename T, typename S>
T bridge_cast(S source) {
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wold-style-cast"
	return (__bridge T)(source);
#pragma clang diagnostic pop
}

namespace Swift {

namespace {

	
CFArrayRef CreateClientCertificateChainAsCFArrayRef(CertificateWithKey::ref key) {
	boost::shared_ptr<PKCS12Certificate> pkcs12 = boost::dynamic_pointer_cast<PKCS12Certificate>(key);
	if (!key) {
		return NULL;
	}

	SafeByteArray safePassword = pkcs12->getPassword();
	CFIndex passwordSize = 0;
	try {
		passwordSize = boost::numeric_cast<CFIndex>(safePassword.size());
	} catch (...) {
		return NULL;
	}

	CFMutableArrayRef certChain = CFArrayCreateMutable(NULL, 0, 0);

	OSStatus securityError = errSecSuccess;
	CFStringRef password = CFStringCreateWithBytes(kCFAllocatorDefault, safePassword.data(), passwordSize, kCFStringEncodingUTF8, false);
	const void* keys[] = { kSecImportExportPassphrase };
	const void* values[] = { password };

	CFDictionaryRef options = CFDictionaryCreate(NULL, keys, values, 1, NULL, NULL);

	CFArrayRef items = NULL;
	CFDataRef pkcs12Data = bridge_cast<CFDataRef>([NSData dataWithBytes: static_cast<const void *>(pkcs12->getData().data()) length:pkcs12->getData().size()]);
	securityError = SecPKCS12Import(pkcs12Data, options, &items);
	CFRelease(options);
	NSArray* nsItems = bridge_cast<NSArray*>(items);

	switch(securityError) {
		case errSecSuccess:
			break;
		case errSecAuthFailed:
			// Password did not work for decoding the certificate.
		case errSecDecode:
			// Other decoding error.
		default:
			CFRelease(certChain);
			CFRelease(items);
			certChain = NULL;
	}

	if (certChain) {
		CFArrayAppendValue(certChain, nsItems[0][@"identity"]);

		for (CFIndex index = 0; index < CFArrayGetCount(bridge_cast<CFArrayRef>(nsItems[0][@"chain"])); index++) {
			CFArrayAppendValue(certChain, CFArrayGetValueAtIndex(bridge_cast<CFArrayRef>(nsItems[0][@"chain"]), index));
		}
	}
	return certChain;
}

}

SecureTransportContext::SecureTransportContext(bool checkCertificateRevocation) : state_(None), checkCertificateRevocation_(checkCertificateRevocation) {
	sslContext_ = boost::shared_ptr<SSLContext>(SSLCreateContext(NULL, kSSLClientSide, kSSLStreamType), CFRelease);

	OSStatus error = noErr;
	// set IO callbacks
	error = SSLSetIOFuncs(sslContext_.get(), &SecureTransportContext::SSLSocketReadCallback, &SecureTransportContext::SSLSocketWriteCallback);
	if (error != noErr) {
		SWIFT_LOG(error) << "Unable to set IO functions to SSL context." << std::endl;
		sslContext_.reset();
	}

	error = SSLSetConnection(sslContext_.get(), this);
	if (error != noErr) {
		SWIFT_LOG(error) << "Unable to set connection to SSL context." << std::endl;
		sslContext_.reset();
	}


	error = SSLSetSessionOption(sslContext_.get(), kSSLSessionOptionBreakOnServerAuth, true);
	if (error != noErr) {
		SWIFT_LOG(error) << "Unable to set kSSLSessionOptionBreakOnServerAuth on session." << std::endl;
		sslContext_.reset();
	}
}

SecureTransportContext::~SecureTransportContext() {
	if (sslContext_) {
		SSLClose(sslContext_.get());
	}
}

std::string SecureTransportContext::stateToString(State state) {
	std::string returnValue;
	switch(state) {
		case Handshake:
			returnValue = "Handshake";
			break;
		case HandshakeDone:
			returnValue = "HandshakeDone";
			break;
		case None:
			returnValue = "None";
			break;
		case Error:
			returnValue = "Error";
			break;
	}
	return returnValue;
}

void SecureTransportContext::setState(State newState) {
	SWIFT_LOG(debug) << "Switch state from " << stateToString(state_) << " to " << stateToString(newState) << "." << std::endl;
	state_ = newState;
}

void SecureTransportContext::connect() {
	SWIFT_LOG_ASSERT(state_ == None, error) << "current state '" << stateToString(state_) << " invalid." << std::endl;
	if (clientCertificate_) {
		CFArrayRef certs = CreateClientCertificateChainAsCFArrayRef(clientCertificate_);
		if (certs) {
			boost::shared_ptr<CFArray> certRefs(certs, CFRelease);
			OSStatus result = SSLSetCertificate(sslContext_.get(), certRefs.get());
			if (result != noErr) {
				SWIFT_LOG(error) << "SSLSetCertificate failed with error " << result << "." << std::endl;
			}
		}
	}
	processHandshake();
}

void SecureTransportContext::processHandshake() {
	SWIFT_LOG_ASSERT(state_ == None || state_ == Handshake, error) << "current state '" << stateToString(state_) << " invalid." << std::endl;
	OSStatus error = SSLHandshake(sslContext_.get());
	if (error == errSSLWouldBlock) {
		setState(Handshake);
	}
	else if (error == noErr) {
		SWIFT_LOG(debug) << "TLS handshake successful." << std::endl;
		setState(HandshakeDone);
		onConnected();
	}
	else if (error == errSSLPeerAuthCompleted) {
		SWIFT_LOG(debug) << "Received server certificate. Start verification." << std::endl;
		setState(Handshake);
		verifyServerCertificate();
	}
	else {
		SWIFT_LOG(debug) << "Error returned from SSLHandshake call is " << error << "." << std::endl;
		fatalError(nativeToTLSError(error), boost::make_shared<CertificateVerificationError>());
	}
}


#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wdeprecated-declarations"

void SecureTransportContext::verifyServerCertificate() {
	SecTrustRef trust = NULL;
	OSStatus error = SSLCopyPeerTrust(sslContext_.get(), &trust);
	if (error != noErr) {
		fatalError(boost::make_shared<TLSError>(), boost::make_shared<CertificateVerificationError>());
		return;
	}
	boost::shared_ptr<SecTrust> trustRef = boost::shared_ptr<SecTrust>(trust, CFRelease);

	if (checkCertificateRevocation_) {
		error = SecTrustSetOptions(trust, kSecTrustOptionRequireRevPerCert | kSecTrustOptionFetchIssuerFromNet);
		if (error != noErr) {
			fatalError(boost::make_shared<TLSError>(), boost::make_shared<CertificateVerificationError>());
			return;
		}
	}

	SecTrustResultType trustResult;
	error = SecTrustEvaluate(trust, &trustResult);
	if (error != errSecSuccess) {
		fatalError(boost::make_shared<TLSError>(), boost::make_shared<CertificateVerificationError>());
		return;
	}

	OSStatus cssmResult = 0;
	switch(trustResult) {
		case kSecTrustResultUnspecified:
			SWIFT_LOG(warning) << "Successful implicit validation. Result unspecified." << std::endl;
			break;
		case kSecTrustResultProceed:
			SWIFT_LOG(warning) << "Validation resulted in explicitly trusted." << std::endl;
			break;
		case kSecTrustResultRecoverableTrustFailure:
			SWIFT_LOG(warning) << "recoverable trust failure" << std::endl;
			error = SecTrustGetCssmResultCode(trust, &cssmResult);
			if (error == errSecSuccess) {
				verificationError_ = CSSMErrorToVerificationError(cssmResult);
				if (cssmResult == CSSMERR_TP_VERIFY_ACTION_FAILED || cssmResult == CSSMERR_APPLETP_INCOMPLETE_REVOCATION_CHECK ) {
					// Find out the reason why the verification failed.
					CFArrayRef certChain;
					CSSM_TP_APPLE_EVIDENCE_INFO* statusChain;
					error = SecTrustGetResult(trustRef.get(), &trustResult, &certChain, &statusChain);
					if (error == errSecSuccess) {
						boost::shared_ptr<CFArray> certChainRef = boost::shared_ptr<CFArray>(certChain, CFRelease);
						for (CFIndex index = 0; index < CFArrayGetCount(certChainRef.get()); index++) {
							for (CFIndex n = 0; n < statusChain[index].NumStatusCodes; n++) {
								// Even though Secure Transport reported CSSMERR_APPLETP_INCOMPLETE_REVOCATION_CHECK on the whole certificate
								// chain, the actual cause can be that a revocation check for a specific cert returned CSSMERR_TP_CERT_REVOKED.
								if (!verificationError_ || verificationError_->getType() == CertificateVerificationError::RevocationCheckFailed) {
									verificationError_ = CSSMErrorToVerificationError(statusChain[index].StatusCodes[n]);
								}
							}
						}
					}
					else {

					}
				}
			}
			else {
				verificationError_ = boost::make_shared<CertificateVerificationError>(CertificateVerificationError::UnknownError);
			}
			break;
		case kSecTrustResultOtherError:
			verificationError_ = boost::make_shared<CertificateVerificationError>(CertificateVerificationError::UnknownError);
			break;
		default:
			SWIFT_LOG(warning) << "Unhandled trust result " << trustResult << "." << std::endl;
			break;
	}
	
	if (verificationError_) {
		setState(Error);
		SSLClose(sslContext_.get());
		sslContext_.reset();
		onError(boost::make_shared<TLSError>());
	}
	else {
		// proceed with handshake
		processHandshake();
	}
}

#pragma clang diagnostic pop

bool SecureTransportContext::setClientCertificate(CertificateWithKey::ref cert) {
	CFArrayRef nativeClientChain = CreateClientCertificateChainAsCFArrayRef(cert);
	if (nativeClientChain) {
		clientCertificate_ = cert;
		CFRelease(nativeClientChain);
		return true;
	}
	else {
		return false;
	}
}

void SecureTransportContext::handleDataFromNetwork(const SafeByteArray& data) {
	SWIFT_LOG(debug) << std::endl;
	SWIFT_LOG_ASSERT(state_ == HandshakeDone || state_ == Handshake, error) << "current state '" << stateToString(state_) << " invalid." << std::endl;

	append(readingBuffer_, data);

	size_t bytesRead = 0;
	OSStatus error = noErr;
	SafeByteArray applicationData;

	switch(state_) {
		case None:
			assert(false && "Invalid state 'None'.");
			break;
		case Handshake:
			processHandshake();
			break;
		case HandshakeDone:
			while (error == noErr) {
				applicationData.resize(readingBuffer_.size());
				error = SSLRead(sslContext_.get(), applicationData.data(), applicationData.size(), &bytesRead);
				if (error == noErr) {
					// Read successful.
				}
				else if (error == errSSLWouldBlock) {
					// Secure Transport does not want more data.
					break;
				}
				else {
					SWIFT_LOG(error) << "SSLRead failed with error " << error << ", read bytes: " << bytesRead << "." << std::endl;
					fatalError(boost::make_shared<TLSError>(), boost::make_shared<CertificateVerificationError>());
					return;
				}

				if (bytesRead > 0) {
					applicationData.resize(bytesRead);
					onDataForApplication(applicationData);
				}
				else {
					break;	
				}
			}
			break;
		case Error:
			SWIFT_LOG(debug) << "Igoring received data in error state." << std::endl;
			break;
	}
}


void SecureTransportContext::handleDataFromApplication(const SafeByteArray& data) {
	size_t processedBytes = 0;
	OSStatus error = SSLWrite(sslContext_.get(), data.data(), data.size(), &processedBytes);
	switch(error) {
		case errSSLWouldBlock:
			SWIFT_LOG(warning) << "Unexpected because the write callback does not block." << std::endl;
			return;
		case errSSLClosedGraceful:
		case noErr:
			return;
		default:
			SWIFT_LOG(warning) << "SSLWrite returned error code: " << error << ", processed bytes: " << processedBytes << std::endl;
			fatalError(boost::make_shared<TLSError>(), boost::shared_ptr<CertificateVerificationError>());
	}
}

std::vector<Certificate::ref> SecureTransportContext::getPeerCertificateChain() const {
	std::vector<Certificate::ref> peerCertificateChain;

	if (sslContext_) {
			typedef boost::remove_pointer<SecTrustRef>::type SecTrust;
			boost::shared_ptr<SecTrust> securityTrust;

			SecTrustRef secTrust = NULL;;
			OSStatus error = SSLCopyPeerTrust(sslContext_.get(), &secTrust);
			if (error == noErr) {
				securityTrust = boost::shared_ptr<SecTrust>(secTrust, CFRelease);

				CFIndex chainSize = SecTrustGetCertificateCount(securityTrust.get());
				for (CFIndex n = 0; n < chainSize; n++) {
					SecCertificateRef certificate = SecTrustGetCertificateAtIndex(securityTrust.get(), n);
					if (certificate) {
						peerCertificateChain.push_back(boost::make_shared<SecureTransportCertificate>(certificate));
					}
				}
			}
			else {
				SWIFT_LOG(warning) << "Failed to obtain peer trust structure; error = " << error << "." << std::endl;
			}
	}

	return peerCertificateChain;
}

CertificateVerificationError::ref SecureTransportContext::getPeerCertificateVerificationError() const {
	return verificationError_;
}

ByteArray SecureTransportContext::getFinishMessage() const {
	SWIFT_LOG(warning) << "Access to TLS handshake finish message is not part of OS X Secure Transport APIs." << std::endl;
	return ByteArray();
}

/**
 *	This I/O callback simulates an asynchronous read to the read buffer of the context. If it is empty, it returns errSSLWouldBlock; else
 *  the data within the buffer is returned.
 */
OSStatus SecureTransportContext::SSLSocketReadCallback(SSLConnectionRef connection, void *data, size_t *dataLength) {
	SecureTransportContext* context = const_cast<SecureTransportContext*>(static_cast<const SecureTransportContext*>(connection));
	OSStatus retValue = noErr;

	if (context->readingBuffer_.size() < *dataLength) {
		// Would block because Secure Transport is trying to read more data than there currently is available in the buffer.
		*dataLength = 0;
		retValue = errSSLWouldBlock;
	}
	else {
		size_t bufferLen = *dataLength;
		size_t copyToBuffer = bufferLen < context->readingBuffer_.size() ? bufferLen : context->readingBuffer_.size();

		memcpy(data, context->readingBuffer_.data(), copyToBuffer);
			
		context->readingBuffer_ = SafeByteArray(context->readingBuffer_.data() + copyToBuffer, context->readingBuffer_.data() + context->readingBuffer_.size());
		*dataLength = copyToBuffer;
	}
	return retValue;
}

OSStatus SecureTransportContext::SSLSocketWriteCallback(SSLConnectionRef connection, const void *data, size_t *dataLength) {
	SecureTransportContext* context = const_cast<SecureTransportContext*>(static_cast<const SecureTransportContext*>(connection));
	OSStatus retValue = noErr;
	
	SafeByteArray safeData;
	safeData.resize(*dataLength);
	memcpy(safeData.data(), data, safeData.size());
	
	context->onDataForNetwork(safeData);
	return retValue;
}

boost::shared_ptr<TLSError> SecureTransportContext::nativeToTLSError(OSStatus /* error */) {
	boost::shared_ptr<TLSError> swiftenError;
	swiftenError = boost::make_shared<TLSError>();
	return swiftenError;
}

boost::shared_ptr<CertificateVerificationError> SecureTransportContext::CSSMErrorToVerificationError(OSStatus resultCode) {
	boost::shared_ptr<CertificateVerificationError> error;
	switch(resultCode) {
		case CSSMERR_TP_NOT_TRUSTED:
			SWIFT_LOG(debug) << "CSSM result code: CSSMERR_TP_NOT_TRUSTED" << std::endl;
			error = boost::make_shared<CertificateVerificationError>(CertificateVerificationError::Untrusted);
			break;
		case CSSMERR_TP_CERT_NOT_VALID_YET:
			SWIFT_LOG(debug) << "CSSM result code: CSSMERR_TP_CERT_NOT_VALID_YET" << std::endl;
			error = boost::make_shared<CertificateVerificationError>(CertificateVerificationError::NotYetValid);
			break;
		case CSSMERR_TP_CERT_EXPIRED:
			SWIFT_LOG(debug) << "CSSM result code: CSSMERR_TP_CERT_EXPIRED" << std::endl;
			error = boost::make_shared<CertificateVerificationError>(CertificateVerificationError::Expired);
			break;
		case CSSMERR_TP_CERT_REVOKED:
			SWIFT_LOG(debug) << "CSSM result code: CSSMERR_TP_CERT_REVOKED" << std::endl;
			error = boost::make_shared<CertificateVerificationError>(CertificateVerificationError::Revoked);
			break;
		case CSSMERR_TP_VERIFY_ACTION_FAILED:
			SWIFT_LOG(debug) << "CSSM result code: CSSMERR_TP_VERIFY_ACTION_FAILED" << std::endl;
			break;
		case CSSMERR_APPLETP_INCOMPLETE_REVOCATION_CHECK:
			SWIFT_LOG(debug) << "CSSM result code: CSSMERR_APPLETP_INCOMPLETE_REVOCATION_CHECK" << std::endl;
			if (checkCertificateRevocation_) {
				error = boost::make_shared<CertificateVerificationError>(CertificateVerificationError::RevocationCheckFailed);
			}
			break;
		case CSSMERR_APPLETP_OCSP_UNAVAILABLE:
			SWIFT_LOG(debug) << "CSSM result code: CSSMERR_APPLETP_OCSP_UNAVAILABLE" << std::endl;
			if (checkCertificateRevocation_) {
				error = boost::make_shared<CertificateVerificationError>(CertificateVerificationError::RevocationCheckFailed);
			}
			break;
		case CSSMERR_APPLETP_SSL_BAD_EXT_KEY_USE:
			SWIFT_LOG(debug) << "CSSM result code: CSSMERR_APPLETP_SSL_BAD_EXT_KEY_USE" << std::endl;
			error = boost::make_shared<CertificateVerificationError>(CertificateVerificationError::InvalidPurpose);
			break;
		default:
			SWIFT_LOG(warning) << "unhandled CSSM error: " << resultCode << ", CSSM_TP_BASE_TP_ERROR: " << CSSM_TP_BASE_TP_ERROR << std::endl;
			error = boost::make_shared<CertificateVerificationError>(CertificateVerificationError::UnknownError);
			break;
	}
	return error;
}

void SecureTransportContext::fatalError(boost::shared_ptr<TLSError> error, boost::shared_ptr<CertificateVerificationError> certificateError) {
	setState(Error);
	if (sslContext_) {
		SSLClose(sslContext_.get());
	}
	verificationError_ = certificateError;
	onError(error);
}

}