On 09/08/2019 14:33, Dan Heinz wrote: > I have a static library using OpenSSL (built as static library with the > no-pinshared parameter in the configuration) that is then included in a DLL that > gets loaded and unloaded many times by the calling application. Now that the > code is in 1.1.1c to allow me to manually shutdown the OpenSSL library, I’ve run > into an issue when loading and unloading my DLL multiple times from the calling > application. I am testing this on Windows 10. A summary of what I am doing: > > 1. Calling executable calls LoadLibrary to load the DLL containing the static > library that uses OpenSSL. > 2. Calling executable calls a function of the now loaded DLL. > 3. The DLL function calls a function in the static library to initialize > OpenSSL using: openssl_result = OPENSSL_init_crypto(OPENSSL_INIT_NO_ATEXIT, > NULL); > 4. The DLL function calls a function in the static library to decrypt some data > using the RSA_private_decrypt OpenSSL API. > 5. The DLL function calls a function in the static library to shutdown OpenSSL > using: OPENSSL_cleanup(); (required) and CRYPTO_cleanup_all_ex_data(); (not > sure if this is needed). > 6. The calling executable uses FreeLibrary to unload the DLL. > 7. The calling executable goes to step 1 to repeat the process. > > Iterating through the above steps always fails on iteration 1077. OpenSLL > reports the error: > error:4088003:rsa routines:RSA_setup_binding:BN lib > > > > After some debugging, I see that the failure happens in the function > CRYPTO_THREAD_init_local in threads_win.c. *key = TlsAlloc(); fails with the > error TLS_OUT_OF_INDEXES. > > Is something not being freed? Is there something additional I need to do at > shutdown? For every call of CRYPTO_THREAD_init_local() while the library is running you should see a matching call to CRYPTO_THREAD_cleanup_local() to cleanup the index (as a result of an OPENSSL_cleanup() call). If you don't see that then an index is leaking. Matt
