- (AFSecurityPolicy*)customSecurityPolicy{

AFSecurityPolicy *securityPolicy = [AFSecurityPolicy policyWithPinningMode:AFSSLPinningModeNone];
NSString *cerPath = [[NSBundle mainBundle] pathForResource:@"server" ofType:@"cer"];
NSData *certData = [NSData dataWithContentsOfFile:cerPath];
[securityPolicy setAllowInvalidCertificates:NO];
[securityPolicy setValidatesDomainName:YES];

//securityPolicy.validatesCertificateChain = NO;
[securityPolicy setPinnedCertificates:[NSKeyedUnarchiver unarchiveObjectWithData:certData]];

return securityPolicy;
}

NSString *url = SERVER_URL;
AFHTTPSessionManager *manager = [AFHTTPSessionManager manager];
manager.responseSerializer.acceptableContentTypes = [NSSet setWithObject:@"application/json"];
manager.securityPolicy = [utils customSecurityPolicy];
[manager GET:url parameters:nil progress:nil success:^(NSURLSessionTask *task, id responseObject) {

    NSLog(@"JSON: %@", responseObject);


} failure:^(NSURLSessionTask *operation, NSError *error) {
    NSLog(@"Error: %@", error);

}];