Question

I have some Python code I’m trying to translate to Obj-C/Cocoa. It requires a network connection; the initialization string is sent in plaintext then the connection is secured.
Basically, it works like this:

sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.connect((host,port))
sock.send( ... )
sock.recv( ... )
sslSock = ssl.wrap_socket(sock)
sslSock.send( ... )
sslSock.recv( ...)

So far, I have the following. First I create the socket connection and the R/W streams:

CFReadStreamRef readStream;
CFWriteStreamRef writeStream;

CFStreamCreatePairWithSocketToHost(kCFAllocatorDefault, (CFStringRef)HOST, PORT, &readStream, &writeStream);

inputStream = (NSInputStream *)readStream;
[inputStream setDelegate:self];
[inputStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];

outputStream = (NSOutputStream *)writeStream;
[outputStream setDelegate:self];
[outputStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];

[inputStream open];
[outputStream open];

When the NSStreamEventOpenCompleted is sent, I store the native socket handle:

NSSocketNativeHandle *socketHandle = [[outputStream propertyForKey:(NSString *)kCFStreamPropertySocketNativeHandle] bytes];

I handle the NSStreamEventHasBytesAvailable and NSStreamEventHasSpaceAvailable events, as appropriate. Then create two new streams from the stored socket handle, and set the SSL properties:

[inputStream close];
[outputStream close];
[inputStream removeFromRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
[outputStream removeFromRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];

CFStreamCreatePairWithSocket(kCFAllocatorDefault, *socketHandle, &readStream, &writeStream);

inputStream = (NSInputStream *)readStream;
[inputStream setDelegate:self];
[inputStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
[inputStream setProperty:NSStreamSocketSecurityLevelSSLv3 forKey:NSStreamSocketSecurityLevelKey];

outputStream = (NSOutputStream *)writeStream;
[outputStream setDelegate:self];
[outputStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
[outputStream setProperty:NSStreamSocketSecurityLevelSSLv3 forKey:NSStreamSocketSecurityLevelKey];

[inputStream open];
[outputStream open];

And this is as far as I get. The NSStreamEventOpenCompleted event is called on both of the new streams, but NSStreamEventHasBytesAvailable and NSStreamEventHasSpaceAvailable events are never raised. Any ideas what I’m doing wrong?

Answer 1

Looks like my problem was two-fold.

1. When creating a connection via CFStreamCreatePairWithSocketToHost, the kCFStreamPropertyShouldCloseNativeSocket property is set to TRUE automatically. It should be FALSE.

   CFStreamCreatePairWithSocketToHost(kCFAllocatorDefault, (CFStringRef)HOST, PORT, &readStream, &writeStream);
   inputStream = (NSInputStream *)readStream;
   [inputStream setDelegate:self];
   [inputStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
   [inputStream setProperty:(id)kCFBooleanFalse forKey:(NSString *)kCFStreamPropertyShouldCloseNativeSocket];
   

2. I wasn’t setting up SSL correctly.

   NSMutableDictionary *sslSettings = [[NSMutableDictionary alloc] init];
   [sslSettings setObject:NSStreamSocketSecurityLevelNegotiatedSSL forKey:(NSString *)kCFStreamSSLLevel];
   [sslSettings setObject:(id)kCFBooleanTrue forKey:(NSString *)kCFStreamSSLAllowsAnyRoot];
   [sslSettings setObject:HOST forKey:(NSString *)kCFStreamSSLPeerName];
   [inputStream setProperty:sslSettings forKey:(NSString *)kCFStreamPropertySSLSettings];
   [inputStream open];