CFStream SSL 错误 -9800

Question

我的 iOS 应用程序包含 2 个版本：服务器和客户端。服务器通过 Bonjour 发布服务并等待客户端。客户端搜索该服务并连接到服务器。之后，所有通信都通过 CFSockets 实现。
这是我为此类通信设置流的代码：

- (BOOL)setupSocketStreams {
if ( readStream == nil || writeStream == nil ) {
    return NO;
}
incomingDataBuffer = [[NSMutableData alloc] init];
outgoingDataBuffer = [[NSMutableData alloc] init];

// Turning SSL on
NSDictionary *sslSettings = [NSDictionary dictionaryWithObjectsAndKeys:(id)kCFBooleanFalse, (id)kCFStreamSSLValidatesCertificateChain, nil];
CFReadStreamSetProperty(readStream, kCFStreamPropertySocketSecurityLevel, kCFStreamSocketSecurityLevelNegotiatedSSL);
CFReadStreamSetProperty(readStream, kCFStreamPropertySSLSettings, sslSettings);
CFWriteStreamSetProperty(writeStream, kCFStreamPropertySocketSecurityLevel, kCFStreamSocketSecurityLevelNegotiatedSSL);
CFWriteStreamSetProperty(writeStream, kCFStreamPropertySSLSettings, sslSettings);

CFReadStreamSetProperty(
        readStream,
        kCFStreamPropertyShouldCloseNativeSocket,
        kCFBooleanTrue
);
CFWriteStreamSetProperty(
        writeStream,
        kCFStreamPropertyShouldCloseNativeSocket,
        kCFBooleanTrue
);

CFOptionFlags registeredEvents =
        kCFStreamEventOpenCompleted     |
                kCFStreamEventHasBytesAvailable |
                kCFStreamEventCanAcceptBytes    |
                kCFStreamEventEndEncountered    |
                kCFStreamEventErrorOccurred
;

CFStreamClientContext ctx = {
        0,      // version
        self,   // info
        NULL,   // retain callback
        NULL,   // release callback
        NULL    // copyDescription callback
};

CFReadStreamSetClient(
        readStream,
        registeredEvents,
        readStreamEventHandler,
        &ctx
);
CFWriteStreamSetClient(
        writeStream,
        registeredEvents,
        writeStreamEventHandler,
        &ctx
);

CFReadStreamScheduleWithRunLoop(
        readStream,
        CFRunLoopGetCurrent(),
        kCFRunLoopCommonModes
);
CFWriteStreamScheduleWithRunLoop(
        writeStream,
        CFRunLoopGetCurrent(),
        kCFRunLoopCommonModes
);

if ( ! CFReadStreamOpen(readStream) || ! CFWriteStreamOpen(writeStream)) {
    [self close];
    return NO;
}

if ([self.delegate respondsToSelector:@selector(establishedConnection:)]) {
    [self.delegate establishedConnection:self];
}

return YES;
}

如果没有在此代码上打开 SSL 可以正常工作，但否则我会收到错误：

Error:
The operation couldn’t be completed. (OSStatus error -9800.)

会是什么问题？
谢谢！

Answer 1

iOS 5 中的 TLS1.2 支持存在一个已知问题：https://developer.apple.com/library/ios/#technotes/tn2287/_index.html#//apple_ref/doc/uid/DTS40011309

通过将 kCFStreamSSLLevel 设置为 @"kCFStreamSocketSecurityLevelTLSv1_0SSLv3" 我能够修复我的应用程序中的 -9800 问题。