如何为SSL握手配置CFStream（或NSStream）？

Question

我正在使用CFStream/NSStream建立超文本传输协议连接。我希望能够检测到SSL握手失败的三种情况：

• 案例A：服务器不受信任

今天，如果不对我的CFStream的SSL属性进行任何操作，我会得到：

• 案例A：错误-9807

有没有办法配置CFStream来正确区分这3种情况？或者在SSL握手期间进行一些回调？

谢谢你的帮助。

Answer 1

不久前，我在使用SSL的CFSockets中遇到了同样的问题。CFStream处理所有握手内容。我为NSStream编写了一个小类添加（基本代码来自Apple，不再有链接，如果我找到它，我会添加它）。这就是我的工作。

接口

@interface NSStream (FSNetworkAdditions)

+ (void)qNetworkAdditions_getStreamsToHostNamed:(NSString *)hostName
                                           port:(NSInteger)port
                                    inputStream:(out NSInputStream **)inputStreamPtr
                                   outputStream:(out NSOutputStream **)outputStreamPtr;

@end

和实施

#import "FSNetworkAdditions.h"

@implementation NSStream (FSNetworkAdditions)

+ (void)qNetworkAdditions_getStreamsToHostNamed:(NSString *)hostName
                                           port:(NSInteger)port
                                    inputStream:(out NSInputStream **)inputStreamPtr
                                   outputStream:(out NSOutputStream **)outputStreamPtr
{
    CFReadStreamRef     readStream;
    CFWriteStreamRef    writeStream;

    assert(hostName != nil);
    assert( (port > 0) && (port < 65536) );
    assert( (inputStreamPtr != NULL) || (outputStreamPtr != NULL) );

    readStream = NULL;
    writeStream = NULL;

    CFStreamCreatePairWithSocketToHost(
                                       NULL,
                                       (CFStringRef) hostName,
                                       port,
                                       ((inputStreamPtr  != NULL) ? &readStream : NULL),
                                       ((outputStreamPtr != NULL) ? &writeStream : NULL)
                                       );

    NSDictionary *settings = [[NSDictionary alloc] initWithObjectsAndKeys:
                              [NSNumber numberWithBool:YES], kCFStreamSSLAllowsExpiredCertificates,
                              [NSNumber numberWithBool:YES], kCFStreamSSLAllowsAnyRoot,
                              [NSNumber numberWithBool:YES], kCFStreamSSLAllowsExpiredRoots,
                              [NSNumber numberWithBool:NO], kCFStreamSSLValidatesCertificateChain,
                              //kCFNull,kCFStreamSSLPeerName,
                              kCFStreamSocketSecurityLevelSSLv3, kCFStreamSSLLevel,
                              [NSNumber numberWithBool:YES], kCFStreamPropertyShouldCloseNativeSocket,
                              nil];

    if (readStream) {
        CFReadStreamSetProperty(readStream, kCFStreamPropertySSLSettings, (CFTypeRef)settings);
    }

    if (writeStream) {
        CFWriteStreamSetProperty(writeStream, kCFStreamPropertySSLSettings, (CFTypeRef)settings);
    }

    if (inputStreamPtr != NULL) {
        *inputStreamPtr  = CFBridgingRelease(readStream);
    }
    if (outputStreamPtr != NULL) {
        *outputStreamPtr = CFBridgingRelease(writeStream);
    }


}

@end

就这样，现在您可以像这样连接到服务器：

NSInputStream   *inputStream;
NSOutputStream  *outputStream;
[NSStream qNetworkAdditions_getStreamsToHostNamed:host 
                                             port:port 
                                      inputStream:&inputStream 
                                     outputStream:&outputStream];

        inputStream.delegate  = self;
        outputStream.delegate = self;

其中“self”符合NSStreamDelegate协议。

我希望这些片段能有所帮助。