I have checked all the DESCRIPTION of Net::SSLeay, even check the code of the IO::Socket::SSL, that module used the Net::SSLeay to make ssl connection. But I can not find any help.
The only clue is about set_info_callback function in Net::SSLeay. But the description is disillusionary:
"Sets the callback function, that can be used to obtain state information for $ssl during connection setup and use. When callback is 0 (NULL), the callback setting currently valid for ctx is used.
??? (does this function really work?)"
# $ssl - value corresponding to openssl's SSL structure
# $cb - pointer to function ???
# returns: no return value
And I have a try, it seem that function can not work well in perl.