nginx与ios实现https双向认证

服务端配置

nginx关键配置如下：

listen       443;server_name  localhost;ssl on;ssl_certificate      /usr/local/opt/nginx/certificates/server.cer;ssl_certificate_key  /usr/local/opt/nginx/certificates/server.key.pem;ssl_client_certificate /usr/local/opt/nginx/certificates/ca.cer;ssl_verify_client    on;

ssl开启https

ssl_certificate是服务端证书的路径，ssl_certificate_key是服务端私钥的路径

ssl_verify_client是配置双向认证（client certificate）

ssl_client_certificate是签发客户端证书的根证书

为什么是根证书，因为可以签发很多客户端证书，只要是由该根证书签发的，服务端都视为认证通过

配置完成以后，一般需要把80端口的http请求跳转到443端口，否则用户可以通过80端口以http方式访问，就失去了安全保护的意义

客户端代码

在网上找了很多ios client certificate的帖子，要么是代码不全，要么是很老的帖子，还是用的NSURLConnection，delegate method都deprecated了，最后找了一个代码片段，改了一下

NSURLSessionConfiguration *configuration = [NSURLSessionConfiguration defaultSessionConfiguration];    NSURLSession *session = [NSURLSession sessionWithConfiguration:configuration delegate:self delegateQueue:nil];    NSURL *url = [NSURL URLWithString:@"https://localhost/svc/portal/setting"];    NSMutableURLRequest *request = [[NSMutableURLRequest alloc] initWithURL:url];[request setCachePolicy:NSURLRequestReloadIgnoringLocalCacheData];[request setHTTPShouldHandleCookies:NO];[request setTimeoutInterval:30];[request setHTTPMethod:@"GET"];    NSURLSessionDataTask *task = [session dataTaskWithURL:url completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {    NSString *message = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];    NSLog(@"%@", message);}];    [task resume];

上面的代码片段，是用NSURLSessionDataTask发起https请求。在ssl握手阶段，会调用2次下面的delegate method

- (void)URLSession:(NSURLSession *)session didReceiveChallenge:(NSURLAuthenticationChallenge *)challenge completionHandler:(void (^)(NSURLSessionAuthChallengeDisposition disposition, NSURLCredential *credential))completionHandler{    NSString *method = challenge.protectionSpace.authenticationMethod;    NSLog(@"%@", method);        if([method isEqualToString:NSURLAuthenticationMethodServerTrust]){                NSString *host = challenge.protectionSpace.host;        NSLog(@"%@", host);                NSURLCredential *credential = [NSURLCredential credentialForTrust:challenge.protectionSpace.serverTrust];        completionHandler(NSURLSessionAuthChallengeUseCredential, credential);        return;    }    NSString *thePath = [[NSBundle mainBundle] pathForResource:@"client" ofType:@"p12"];    NSData *PKCS12Data = [[NSData alloc] initWithContentsOfFile:thePath];    CFDataRef inPKCS12Data = (CFDataRef)CFBridgingRetain(PKCS12Data);    SecIdentityRef identity;        // 读取p12证书中的内容    OSStatus result = [self extractP12Data:inPKCS12Data toIdentity:&identity];    if(result != errSecSuccess){        completionHandler(NSURLSessionAuthChallengeCancelAuthenticationChallenge, nil);        return;    }        SecCertificateRef certificate = NULL;    SecIdentityCopyCertificate (identity, &certificate);        const void *certs[] = {certificate};    CFArrayRef certArray = CFArrayCreate(kCFAllocatorDefault, certs, 1, NULL);        NSURLCredential *credential = [NSURLCredential credentialWithIdentity:identity certificates:(NSArray*)CFBridgingRelease(certArray) persistence:NSURLCredentialPersistencePermanent];        completionHandler(NSURLSessionAuthChallengeUseCredential, credential);}-(OSStatus) extractP12Data:(CFDataRef)inP12Data toIdentity:(SecIdentityRef*)identity {        OSStatus securityError = errSecSuccess;        CFStringRef password = CFSTR("the_password");    const void *keys[] = { kSecImportExportPassphrase };    const void *values[] = { password };        CFDictionaryRef options = CFDictionaryCreate(NULL, keys, values, 1, NULL, NULL);        CFArrayRef items = CFArrayCreate(NULL, 0, 0, NULL);    securityError = SecPKCS12Import(inP12Data, options, &items);        if (securityError == 0) {        CFDictionaryRef ident = CFArrayGetValueAtIndex(items,0);        const void *tempIdentity = NULL;        tempIdentity = CFDictionaryGetValue(ident, kSecImportItemIdentity);        *identity = (SecIdentityRef)tempIdentity;    }        if (options) {        CFRelease(options);    }        return securityError;}

上面的代码片段，即拷即用，希望能有所帮助。这个方法会被调用2次，第一次是ios app验证server的阶段，第二次是server验证ios app的阶段，即client certificate。关键是每个阶段的校验完成以后，要调用completionHandler方法。网上的大部分帖子都是

[[challenge sender] useCredential:credential forAuthenticationChallenge:challenge];

这行代码是无效的