Debug logs for TLS alerts contain wrong messages

[djelinski]

While examining debug output of #2801, I noticed that the debug output for TLS alerts is garbage. The output currently reads:

TLSv1.2 (IN), TLS alert, Client hello (1):

I expected the following

TLSv1.2 (IN), TLS alert, warning / close notify (1/0)

curl/libcurl version

[curl -V output]
curl 7.60.0 (i386-pc-win32) libcurl/7.60.0 OpenSSL/1.1.0h (WinSSL) zlib/1.2.11 brotli/1.0.4 WinIDN libssh2/1.8.0 nghttp2/1.32.0
Release-Date: 2018-05-16
Protocols: dict file ftp ftps gopher http https imap imaps ldap ldaps pop3 pop3s rtsp scp sftp smb smbs smtp smtps telnet tftp
Features: AsynchDNS IDN IPv6 Largefile SSPI Kerberos SPNEGO NTLM SSL libz brotli TLS-SRP HTTP2 HTTPS-proxy MultiSSL

operating system

Windows 2008R2

[bagder]

Any suggestion on how to reproduce this?

[djelinski]

Gist of code used to reproduce:

curl_easy_setopt(curl, CURLOPT_URL, "https://s3.amazonaws.com");
curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L);
curl_easy_setopt(curl, CURLOPT_DEBUGFUNCTION, DebugCallback);
curl_easy_perform(curl);
Sleep(5950); // experimental, server seems to close connection after about this time
curl_easy_perform(curl);

Debug function:

int DebugCallback(CURL *handle,curl_infotype type,char *datasize_t size,void *userptr)
{
if(type >= CURLINFO_DATA_OUT) return 0;
printf("%s",string(data, data+size).c_str());
return 0;
}

It seems to me that the detailed messages are only valid for TLS handshake, for other message types they don't make sense.