ios下https代理访问证书问题

在ios下，需要打开https链接，但是如果其中使用了代理访问，则会被默认返回证书验证错误，无法正常访问

通常是在国内访问国外facebook的情况下

这是因为

https访问的时候，会验证一次证书，如果用了代理，证书验证的时候会被认为有风险，则会拒绝掉连接

也就是为了避免中间人攻击而做的限制

这里可以考虑先用NSURLConnection创建一个https连接，让本次针对目标地址的连接在验证时忽略证书，就可以保证之后的连接再也没证书验证问题了

           NSString* strUrl = [NSString stringWithFormat:@https://graph.facebook.com/me];
           NSURLRequest* reqUrl = [NSURLRequest requestWithURL:[NSURL URLWithString:strUrl]];
           NSURLConnection* conn = [NSURLConnection connectionWithRequest:reqUrl delegate:self];
           [conn start];

- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
{
    NSLog(@"connection didFailWithError result: %@", error);
}
- (BOOL)connectionShouldUseCredentialStorage:(NSURLConnection *)connection
{
    return NO;
}

- (void)connection:(NSURLConnection *)connection willSendRequestForAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge
{

   //第一次验证通过，之后取消验证

    if ([challenge previousFailureCount] ==0)

    {
        NSURLCredential *credential = [NSURLCredential credentialForTrust:challenge.protectionSpace.serverTrust];        [[challenge sender] useCredential:credential forAuthenticationChallenge:challenge];
    }
    else
    {
        [[challenge sender] cancelAuthenticationChallenge:challenge];
    }
}

// Deprecated authentication delegates.
- (BOOL)connection:(NSURLConnection *)connection canAuthenticateAgainstProtectionSpace:(NSURLProtectionSpace *)protectionSpace
{
    return [protectionSpace.authenticationMethod isEqualToString:NSURLAuthenticationMethodServerTrust];
}

- (void)connection:(NSURLConnection *)connection didReceiveAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge
{

   //第一次验证通过，之后取消验证
    if ([challenge previousFailureCount] ==0)

    {
        NSURLCredential *credential = [NSURLCredential credentialForTrust:challenge.protectionSpace.serverTrust];          [[challenge sender] useCredential:credential forAuthenticationChallenge:challenge];    }
    else
    {
        [[challenge sender] cancelAuthenticationChallenge:challenge];
    }
}
- (void)connection:(NSURLConnection *)connection didCancelAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge
{

}

- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
    //做你需要做的事情

}

不过这个最好看看最新的sdk支不支持了。。