Socket reads with SSL delegate recv failing on osx and linux

[na-gupta]

Socket reads with SSL delegate recv() fails on linux and mac depending on the size of the incoming data.

It looks like it has something to do with how errSSLWouldBlock/SSL_ERROR_WANT_* is handled in SSLService recv:

#if os(Linux)
    if lastError == SSL_ERROR_WANT_READ || lastError == SSL_ERROR_WANT_WRITE {
        errno = EAGAIN
        return 0
    }
#else
    if status == errSSLWouldBlock {
        errno = EWOULDBLOCK
        return Int(errSSLWouldBlock)
    }
#endif

... but in Socket readDataIntoStorage() and readDatagramIntoStorage(), it appears to be expecting delegate.recv() to throw SSLError.retryNeeded when this happens.

It appears to fails when the data is >= 4096 bytes and

• on linux when the data is an exact multiple of 4096 (say 4096 bytes)
• on osx when the data is NOT an exact multiple of 4096 (say 4097 bytes)

[shmuelk]

Inside BlueSocket there is an internal buffer which I believe by default is 4K in size.

[na-gupta]

This issue can be replicated on linux and osx using the BlueSSLService_22 branch of Kitura by running swift test -s KituraTests.TestResponse/testLargePost

[na-gupta]

@shmuelk Yes, @billabt and I were chatting about that earlier. The number of bytes that cause the failure depends on the size of that buffer, but the fix is unclear.

[billabt]

This is fixed in v0.12.39 of BlueSocket.