AFSecurityPolicy.m 12 KB

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  1. // AFSecurityPolicy.m
  2. // Copyright (c) 2011–2015 Alamofire Software Foundation (http://alamofire.org/)
  3. //
  4. // Permission is hereby granted, free of charge, to any person obtaining a copy
  5. // of this software and associated documentation files (the "Software"), to deal
  6. // in the Software without restriction, including without limitation the rights
  7. // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  8. // copies of the Software, and to permit persons to whom the Software is
  9. // furnished to do so, subject to the following conditions:
  10. //
  11. // The above copyright notice and this permission notice shall be included in
  12. // all copies or substantial portions of the Software.
  13. //
  14. // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  15. // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  16. // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  17. // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  18. // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  19. // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  20. // THE SOFTWARE.
  21. #import "AFSecurityPolicy.h"
  22. #import <AssertMacros.h>
  23. #if !TARGET_OS_IOS && !TARGET_OS_WATCH
  24. static NSData * AFSecKeyGetData(SecKeyRef key) {
  25. CFDataRef data = NULL;
  26. __Require_noErr_Quiet(SecItemExport(key, kSecFormatUnknown, kSecItemPemArmour, NULL, &data), _out);
  27. return (__bridge_transfer NSData *)data;
  28. _out:
  29. if (data) {
  30. CFRelease(data);
  31. }
  32. return nil;
  33. }
  34. #endif
  35. static BOOL AFSecKeyIsEqualToKey(SecKeyRef key1, SecKeyRef key2) {
  36. #if TARGET_OS_IOS || TARGET_OS_WATCH
  37. return [(__bridge id)key1 isEqual:(__bridge id)key2];
  38. #else
  39. return [AFSecKeyGetData(key1) isEqual:AFSecKeyGetData(key2)];
  40. #endif
  41. }
  42. static id AFPublicKeyForCertificate(NSData *certificate) {
  43. id allowedPublicKey = nil;
  44. SecCertificateRef allowedCertificate;
  45. SecCertificateRef allowedCertificates[1];
  46. CFArrayRef tempCertificates = nil;
  47. SecPolicyRef policy = nil;
  48. SecTrustRef allowedTrust = nil;
  49. SecTrustResultType result;
  50. allowedCertificate = SecCertificateCreateWithData(NULL, (__bridge CFDataRef)certificate);
  51. __Require_Quiet(allowedCertificate != NULL, _out);
  52. allowedCertificates[0] = allowedCertificate;
  53. tempCertificates = CFArrayCreate(NULL, (const void **)allowedCertificates, 1, NULL);
  54. policy = SecPolicyCreateBasicX509();
  55. __Require_noErr_Quiet(SecTrustCreateWithCertificates(tempCertificates, policy, &allowedTrust), _out);
  56. __Require_noErr_Quiet(SecTrustEvaluate(allowedTrust, &result), _out);
  57. allowedPublicKey = (__bridge_transfer id)SecTrustCopyPublicKey(allowedTrust);
  58. _out:
  59. if (allowedTrust) {
  60. CFRelease(allowedTrust);
  61. }
  62. if (policy) {
  63. CFRelease(policy);
  64. }
  65. if (tempCertificates) {
  66. CFRelease(tempCertificates);
  67. }
  68. if (allowedCertificate) {
  69. CFRelease(allowedCertificate);
  70. }
  71. return allowedPublicKey;
  72. }
  73. static BOOL AFServerTrustIsValid(SecTrustRef serverTrust) {
  74. BOOL isValid = NO;
  75. SecTrustResultType result;
  76. __Require_noErr_Quiet(SecTrustEvaluate(serverTrust, &result), _out);
  77. isValid = (result == kSecTrustResultUnspecified || result == kSecTrustResultProceed);
  78. _out:
  79. return isValid;
  80. }
  81. static NSArray * AFCertificateTrustChainForServerTrust(SecTrustRef serverTrust) {
  82. CFIndex certificateCount = SecTrustGetCertificateCount(serverTrust);
  83. NSMutableArray *trustChain = [NSMutableArray arrayWithCapacity:(NSUInteger)certificateCount];
  84. for (CFIndex i = 0; i < certificateCount; i++) {
  85. SecCertificateRef certificate = SecTrustGetCertificateAtIndex(serverTrust, i);
  86. [trustChain addObject:(__bridge_transfer NSData *)SecCertificateCopyData(certificate)];
  87. }
  88. return [NSArray arrayWithArray:trustChain];
  89. }
  90. static NSArray * AFPublicKeyTrustChainForServerTrust(SecTrustRef serverTrust) {
  91. SecPolicyRef policy = SecPolicyCreateBasicX509();
  92. CFIndex certificateCount = SecTrustGetCertificateCount(serverTrust);
  93. NSMutableArray *trustChain = [NSMutableArray arrayWithCapacity:(NSUInteger)certificateCount];
  94. for (CFIndex i = 0; i < certificateCount; i++) {
  95. SecCertificateRef certificate = SecTrustGetCertificateAtIndex(serverTrust, i);
  96. SecCertificateRef someCertificates[] = {certificate};
  97. CFArrayRef certificates = CFArrayCreate(NULL, (const void **)someCertificates, 1, NULL);
  98. SecTrustRef trust;
  99. __Require_noErr_Quiet(SecTrustCreateWithCertificates(certificates, policy, &trust), _out);
  100. SecTrustResultType result;
  101. __Require_noErr_Quiet(SecTrustEvaluate(trust, &result), _out);
  102. [trustChain addObject:(__bridge_transfer id)SecTrustCopyPublicKey(trust)];
  103. _out:
  104. if (trust) {
  105. CFRelease(trust);
  106. }
  107. if (certificates) {
  108. CFRelease(certificates);
  109. }
  110. continue;
  111. }
  112. CFRelease(policy);
  113. return [NSArray arrayWithArray:trustChain];
  114. }
  115. #pragma mark -
  116. @interface AFSecurityPolicy()
  117. @property (readwrite, nonatomic, assign) AFSSLPinningMode SSLPinningMode;
  118. @property (readwrite, nonatomic, strong) NSArray *pinnedPublicKeys;
  119. @end
  120. @implementation AFSecurityPolicy
  121. + (NSArray *)defaultPinnedCertificates {
  122. static NSArray *_defaultPinnedCertificates = nil;
  123. static dispatch_once_t onceToken;
  124. dispatch_once(&onceToken, ^{
  125. NSBundle *bundle = [NSBundle bundleForClass:[self class]];
  126. NSArray *paths = [bundle pathsForResourcesOfType:@"cer" inDirectory:@"."];
  127. NSMutableArray *certificates = [NSMutableArray arrayWithCapacity:[paths count]];
  128. for (NSString *path in paths) {
  129. NSData *certificateData = [NSData dataWithContentsOfFile:path];
  130. [certificates addObject:certificateData];
  131. }
  132. _defaultPinnedCertificates = [[NSArray alloc] initWithArray:certificates];
  133. });
  134. return _defaultPinnedCertificates;
  135. }
  136. + (instancetype)defaultPolicy {
  137. AFSecurityPolicy *securityPolicy = [[self alloc] init];
  138. securityPolicy.SSLPinningMode = AFSSLPinningModeNone;
  139. return securityPolicy;
  140. }
  141. + (instancetype)policyWithPinningMode:(AFSSLPinningMode)pinningMode {
  142. AFSecurityPolicy *securityPolicy = [[self alloc] init];
  143. securityPolicy.SSLPinningMode = pinningMode;
  144. [securityPolicy setPinnedCertificates:[self defaultPinnedCertificates]];
  145. return securityPolicy;
  146. }
  147. - (id)init {
  148. self = [super init];
  149. if (!self) {
  150. return nil;
  151. }
  152. self.validatesDomainName = YES;
  153. return self;
  154. }
  155. - (void)setPinnedCertificates:(NSArray *)pinnedCertificates {
  156. _pinnedCertificates = [[NSOrderedSet orderedSetWithArray:pinnedCertificates] array];
  157. if (self.pinnedCertificates) {
  158. NSMutableArray *mutablePinnedPublicKeys = [NSMutableArray arrayWithCapacity:[self.pinnedCertificates count]];
  159. for (NSData *certificate in self.pinnedCertificates) {
  160. id publicKey = AFPublicKeyForCertificate(certificate);
  161. if (!publicKey) {
  162. continue;
  163. }
  164. [mutablePinnedPublicKeys addObject:publicKey];
  165. }
  166. self.pinnedPublicKeys = [NSArray arrayWithArray:mutablePinnedPublicKeys];
  167. } else {
  168. self.pinnedPublicKeys = nil;
  169. }
  170. }
  171. #pragma mark -
  172. - (BOOL)evaluateServerTrust:(SecTrustRef)serverTrust {
  173. return [self evaluateServerTrust:serverTrust forDomain:nil];
  174. }
  175. - (BOOL)evaluateServerTrust:(SecTrustRef)serverTrust
  176. forDomain:(NSString *)domain
  177. {
  178. if (domain && self.allowInvalidCertificates && self.validatesDomainName && (self.SSLPinningMode == AFSSLPinningModeNone || [self.pinnedCertificates count] == 0)) {
  179. // https://developer.apple.com/library/mac/documentation/NetworkingInternet/Conceptual/NetworkingTopics/Articles/OverridingSSLChainValidationCorrectly.html
  180. // According to the docs, you should only trust your provided certs for evaluation.
  181. // Pinned certificates are added to the trust. Without pinned certificates,
  182. // there is nothing to evaluate against.
  183. //
  184. // From Apple Docs:
  185. // "Do not implicitly trust self-signed certificates as anchors (kSecTrustOptionImplicitAnchors).
  186. // Instead, add your own (self-signed) CA certificate to the list of trusted anchors."
  187. NSLog(@"In order to validate a domain name for self signed certificates, you MUST use pinning.");
  188. return NO;
  189. }
  190. NSMutableArray *policies = [NSMutableArray array];
  191. if (self.validatesDomainName) {
  192. [policies addObject:(__bridge_transfer id)SecPolicyCreateSSL(true, (__bridge CFStringRef)domain)];
  193. } else {
  194. [policies addObject:(__bridge_transfer id)SecPolicyCreateBasicX509()];
  195. }
  196. SecTrustSetPolicies(serverTrust, (__bridge CFArrayRef)policies);
  197. if (self.SSLPinningMode == AFSSLPinningModeNone) {
  198. return self.allowInvalidCertificates || AFServerTrustIsValid(serverTrust);
  199. } else if (!AFServerTrustIsValid(serverTrust) && !self.allowInvalidCertificates) {
  200. return NO;
  201. }
  202. NSArray *serverCertificates = AFCertificateTrustChainForServerTrust(serverTrust);
  203. switch (self.SSLPinningMode) {
  204. case AFSSLPinningModeNone:
  205. default:
  206. return NO;
  207. case AFSSLPinningModeCertificate: {
  208. NSMutableArray *pinnedCertificates = [NSMutableArray array];
  209. for (NSData *certificateData in self.pinnedCertificates) {
  210. [pinnedCertificates addObject:(__bridge_transfer id)SecCertificateCreateWithData(NULL, (__bridge CFDataRef)certificateData)];
  211. }
  212. SecTrustSetAnchorCertificates(serverTrust, (__bridge CFArrayRef)pinnedCertificates);
  213. if (!AFServerTrustIsValid(serverTrust)) {
  214. return NO;
  215. }
  216. NSUInteger trustedCertificateCount = 0;
  217. for (NSData *trustChainCertificate in serverCertificates) {
  218. if ([self.pinnedCertificates containsObject:trustChainCertificate]) {
  219. trustedCertificateCount++;
  220. }
  221. }
  222. return trustedCertificateCount > 0;
  223. }
  224. case AFSSLPinningModePublicKey: {
  225. NSUInteger trustedPublicKeyCount = 0;
  226. NSArray *publicKeys = AFPublicKeyTrustChainForServerTrust(serverTrust);
  227. for (id trustChainPublicKey in publicKeys) {
  228. for (id pinnedPublicKey in self.pinnedPublicKeys) {
  229. if (AFSecKeyIsEqualToKey((__bridge SecKeyRef)trustChainPublicKey, (__bridge SecKeyRef)pinnedPublicKey)) {
  230. trustedPublicKeyCount += 1;
  231. }
  232. }
  233. }
  234. return trustedPublicKeyCount > 0;
  235. }
  236. }
  237. return NO;
  238. }
  239. #pragma mark - NSKeyValueObserving
  240. + (NSSet *)keyPathsForValuesAffectingPinnedPublicKeys {
  241. return [NSSet setWithObject:@"pinnedCertificates"];
  242. }
  243. #pragma mark - NSSecureCoding
  244. + (BOOL)supportsSecureCoding {
  245. return YES;
  246. }
  247. - (instancetype)initWithCoder:(NSCoder *)decoder {
  248. self = [self init];
  249. if (!self) {
  250. return nil;
  251. }
  252. self.SSLPinningMode = [[decoder decodeObjectOfClass:[NSNumber class] forKey:NSStringFromSelector(@selector(SSLPinningMode))] unsignedIntegerValue];
  253. self.allowInvalidCertificates = [decoder decodeBoolForKey:NSStringFromSelector(@selector(allowInvalidCertificates))];
  254. self.validatesDomainName = [decoder decodeBoolForKey:NSStringFromSelector(@selector(validatesDomainName))];
  255. self.pinnedCertificates = [decoder decodeObjectOfClass:[NSArray class] forKey:NSStringFromSelector(@selector(pinnedCertificates))];
  256. return self;
  257. }
  258. - (void)encodeWithCoder:(NSCoder *)coder {
  259. [coder encodeObject:[NSNumber numberWithUnsignedInteger:self.SSLPinningMode] forKey:NSStringFromSelector(@selector(SSLPinningMode))];
  260. [coder encodeBool:self.allowInvalidCertificates forKey:NSStringFromSelector(@selector(allowInvalidCertificates))];
  261. [coder encodeBool:self.validatesDomainName forKey:NSStringFromSelector(@selector(validatesDomainName))];
  262. [coder encodeObject:self.pinnedCertificates forKey:NSStringFromSelector(@selector(pinnedCertificates))];
  263. }
  264. #pragma mark - NSCopying
  265. - (instancetype)copyWithZone:(NSZone *)zone {
  266. AFSecurityPolicy *securityPolicy = [[[self class] allocWithZone:zone] init];
  267. securityPolicy.SSLPinningMode = self.SSLPinningMode;
  268. securityPolicy.allowInvalidCertificates = self.allowInvalidCertificates;
  269. securityPolicy.validatesDomainName = self.validatesDomainName;
  270. securityPolicy.pinnedCertificates = [self.pinnedCertificates copyWithZone:zone];
  271. return securityPolicy;
  272. }
  273. @end