iOS13 ios-webkit-debug-proxy will disconnected Once the Json is over 200k

[liu6x6]

hi there
today i found an issue on iOS13, and i am using the wdp_client.html to send json string to the safari. Once the JSON size is over than 200KB, then iOS-webkit-debug-proxy will disconnected.

the error logs like:
_

ss.sendq<0x7fb70d504630> new fd=10 recv_fd=14 length=200416, prev=<0x0>
ss.sendq<0x7fb70d504630> disable recv_fd=14
ss.sendq<0x7fb70d504630> resume send to fd=10 len=200416
ssl sendq retry failed: Undefined error: 0
ss.remove_fd(10)
Disconnected :9222 from xiao’s iPhone (9cd6921d1f5f908f06f295b52b0346aacca81234)
ss.remove_server_fd(5)
ss.remove_fd(14)
ss.remove_fd(9)
ss.remove_fd(12)
ss.remove_fd(11)
ss.remove_fd(13)
^Css.remove_server_fd(3)
ss.remove_fd(4)

_

my json command look like:

{"id":8,"method":"Target.sendMessageToTarget","params":{"objectGroup":"console","includeCommandLineAPI":true,"doNotPauseOnExceptionsAndMuteConsole":true,"message":"{"method":"Runtime.evaluate","params":{"expression":"var func = function(){console.debug(\"touch\");console.debug(\"touch\"); ...
;}, true);};func();"},"id":8}","id":8,"targetId":"page-6"}}

I add lot of console.debug(\"touch\"); to make sure the json size is big enough.
it's the SSL problem? how can i fix this?

[liu6x6]

After some inverstgation i found there are 2 problems. hope someone can tell me the reason.
The problem is at socket_manager.c sm_send function

1. Once the data length bigger than 131000 then SSL_write will always return -1
2. So i split the data size. i send 130000 each time. But the last one (the size is small then 130000) will always return -1, so I add a sleep(1) after the SSL_write. And then it working.

The code like this:
long sendLength = tail - head;
if (sendLength >= 130000) {
sendLength = 130000;
}
sent_bytes = SSL_write((SSL )ssl_session, (void)head, sendLength);
sleep(1);

I am not good at C and ssl. Hope someone could help me.

[artygus]

hi @liu6x6 interesting observation 🤔 I got back from holidays, will take a look possible this weekend. what OS are you using?

[ElielCohen]

Hi @artygus , I'm working with @liu6x6 and I've experienced similar issue on any platform, macOS, linux, and windows. The issue is happening as soon as the idevice is running on iOS13+. Any idea what have changed there ? I know that from iOS13+ we are obliged to use SSL for the web inspector communication it's probably linked.