two days ago I investigated why on specific HTTPS URL check_http plugin throwed
"HTTP CRITICAL - Error on receive". My Iceweasel and wget had no problem with
this URL. I founded source of this error in sslutils.c in "int
np_net_ssl_read(void *buf, int num)" function. This function calls
"SSL_read(s, buf, num)" and got error SSL_ERROR_WANT_READ.
OpenSSL documentation explains it as state when operation did not completed
and the SSL_read should be called again later (http://www.openssl.org/docs/ssl/SSL_get_error.html).
But check_http didn't do it. I have made small changes also in
"int np_net_ssl_write(const void *buf, int num)" to solve my problem and I'm sending
diff file to you. I hope it will be usefull for you.
Have a nice day