OpenSSL memory leak without call to SSL_COMP_free_compression_methods #817
Description
I did this
`
/* Memory leak detecting */
#define _CRTDBG_MAP_ALLOC
#include <stdlib.h>
#include <crtdbg.h>
#define WIN32_LEAN_AND_MEAN
#include <Windows.h>
#include <tchar.h>
#ifndef CURL_STATICLIB
#define CURL_STATICLIB
#endif
#include <curl/curl.h>
#pragma comment(lib, "libcurl_a.lib")
int _tmain(int argc, _TCHAR* argv[])
{
_CrtSetReportMode(_CRT_ERROR, _CRTDBG_MODE_DEBUG | _CRTDBG_MODE_FILE);
_CrtSetReportFile(_CRT_ERROR, _CRTDBG_FILE_STDERR );
_CrtSetReportMode(_CRT_WARN, _CRTDBG_MODE_DEBUG | _CRTDBG_MODE_FILE);
_CrtSetReportFile(_CRT_WARN, _CRTDBG_FILE_STDERR );
_CrtSetReportMode(_CRT_ASSERT, _CRTDBG_MODE_DEBUG | _CRTDBG_MODE_FILE);
_CrtSetReportFile(_CRT_ASSERT, _CRTDBG_FILE_STDERR );
_CrtSetDbgFlag (_CRTDBG_ALLOC_MEM_DF | _CRTDBG_LEAK_CHECK_DF );
CURLcode output = curl_global_init(CURL_GLOBAL_ALL);
curl_global_cleanup();
_CrtDumpMemoryLeaks( );
return 0;
}
`
It displayed the following
`
Detected memory leaks!
Dumping objects ->
{2966} normal block at 0x02499DF8, 16 bytes long.
Data: < > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
{2965} normal block at 0x024988F0, 20 bytes long.
Data: < I > 00 00 00 00 F8 9D 49 02 01 00 00 00 04 00 00 00
Object dump complete.
`
Possible fix
Calling SSL_COMP_free_compression_methods(); after curl_global_cleanup(); appears to fix the problem.
See also #2561: Memory leak with SSL built-in compressions
curl/libcurl version
curl 7.48.0 (i386-pc-win32) libcurl/7.48.0 OpenSSL/1.0.2h zlib/1.2.8 WinIDN
Protocols: dict file ftp ftps gopher http https imap imaps ldap pop3 pop3s rtsp smtp smtps telnet tftp
Features: AsynchDNS IDN IPv6 Largefile SSPI Kerberos SPNEGO NTLM SSL libz
operating system
Windows 10