From e5c1d346e29e5b1227ed30ee4d725a09eca0e532 Mon Sep 17 00:00:00 2001 From: Sverker Eriksson Date: Fri, 5 Oct 2012 11:52:52 +0200 Subject: crypto: Make unloading of crypto safer Facts: crypto nif-lib registers callback functions that openssl uses for memory management and thread synchronization. The callback functions can only be set once, openssl does not allow changing the callback functions. Problem: If openssl is dynamicly linked to crypto, you might get s scenario where the crypto lib is unloaded while leaving openssl loaded with its old pointers to the unloaded crypto code intact. If crypto is then reloaded (by init:restart() for example), the crypto nif-lib might get relocated at a different address. crypto calls openssl which in turn calls the old invalid callback functions...kaboom. Solution: Break apart the callback functions into a separate dynamic lib that crypto loads with dlopen. When crypto is unloaded the callback lib is left in place to be reused if/when crypto is loaded again. --- erts/emulator/beam/erl_nif.c | 38 ++++++++++++++++++++++++++++ erts/emulator/beam/erl_nif_api_funcs.h | 4 +++ erts/emulator/beam/sys.h | 4 +-- erts/emulator/sys/unix/erl_unix_sys_ddll.c | 4 +-- erts/emulator/sys/win32/erl_win32_sys_ddll.c | 4 +-- 5 files changed, 48 insertions(+), 6 deletions(-) (limited to 'erts') diff --git a/erts/emulator/beam/erl_nif.c b/erts/emulator/beam/erl_nif.c index 0dca588847..632d756481 100644 --- a/erts/emulator/beam/erl_nif.c +++ b/erts/emulator/beam/erl_nif.c @@ -1396,6 +1396,44 @@ size_t enif_sizeof_resource(void* obj) return ERTS_MAGIC_BIN_DATA_SIZE(bin) - offsetof(ErlNifResource,data); } + +void* enif_dlopen(const char* lib, + void (*err_handler)(void*,const char*), void* err_arg) +{ + ErtsSysDdllError errdesc = ERTS_SYS_DDLL_ERROR_INIT; + void* handle; + void* init_func; + if (erts_sys_ddll_open2(lib, &handle, &errdesc) == ERL_DE_NO_ERROR) { + if (erts_sys_ddll_load_nif_init(handle, &init_func, &errdesc) == ERL_DE_NO_ERROR) { + erts_sys_ddll_call_nif_init(init_func); + } + } + else { + if (err_handler != NULL) { + (*err_handler)(err_arg, errdesc.str); + } + handle = NULL; + } + erts_sys_ddll_free_error(&errdesc); + return handle; +} + +void* enif_dlsym(void* handle, const char* symbol, + void (*err_handler)(void*,const char*), void* err_arg) +{ + ErtsSysDdllError errdesc = ERTS_SYS_DDLL_ERROR_INIT; + void* ret; + if (erts_sys_ddll_sym2(handle, symbol, &ret, &errdesc) != ERL_DE_NO_ERROR) { + if (err_handler != NULL) { + (*err_handler)(err_arg, errdesc.str); + } + erts_sys_ddll_free_error(&errdesc); + return NULL; + } + return ret; +} + + /*************************************************************************** ** load_nif/2 ** ***************************************************************************/ diff --git a/erts/emulator/beam/erl_nif_api_funcs.h b/erts/emulator/beam/erl_nif_api_funcs.h index 6396af09d0..51ff1eaa48 100644 --- a/erts/emulator/beam/erl_nif_api_funcs.h +++ b/erts/emulator/beam/erl_nif_api_funcs.h @@ -138,6 +138,8 @@ ERL_NIF_API_FUNC_DECL(ERL_NIF_TERM,enif_make_uint64,(ErlNifEnv*, ErlNifUInt64)); ERL_NIF_API_FUNC_DECL(int,enif_is_exception,(ErlNifEnv*, ERL_NIF_TERM term)); ERL_NIF_API_FUNC_DECL(int,enif_make_reverse_list,(ErlNifEnv*, ERL_NIF_TERM term, ERL_NIF_TERM *list)); ERL_NIF_API_FUNC_DECL(int,enif_is_number,(ErlNifEnv*, ERL_NIF_TERM term)); +ERL_NIF_API_FUNC_DECL(void*,enif_dlopen,(const char* lib, void (*err_handler)(void*,const char*), void* err_arg)); +ERL_NIF_API_FUNC_DECL(void*,enif_dlsym,(void* handle, const char* symbol, void (*err_handler)(void*,const char*), void* err_arg)); /* ** Add new entries here to keep compatibility on Windows!!! @@ -260,6 +262,8 @@ ERL_NIF_API_FUNC_DECL(int,enif_is_number,(ErlNifEnv*, ERL_NIF_TERM term)); # define enif_is_exception ERL_NIF_API_FUNC_MACRO(enif_is_exception) # define enif_make_reverse_list ERL_NIF_API_FUNC_MACRO(enif_make_reverse_list) # define enif_is_number ERL_NIF_API_FUNC_MACRO(enif_is_number) +# define enif_dlopen ERL_NIF_API_FUNC_MACRO(enif_dlopen) +# define enif_dlsym ERL_NIF_API_FUNC_MACRO(enif_dlsym) /* ** Add new entries here diff --git a/erts/emulator/beam/sys.h b/erts/emulator/beam/sys.h index 0e6bec352e..743da4ca3a 100644 --- a/erts/emulator/beam/sys.h +++ b/erts/emulator/beam/sys.h @@ -618,7 +618,7 @@ typedef struct { #define ERTS_SYS_DDLL_ERROR_INIT {NULL} extern void erts_sys_ddll_free_error(ErtsSysDdllError*); extern void erl_sys_ddll_init(void); /* to initialize mutexes etc */ -extern int erts_sys_ddll_open2(char *path, void **handle, ErtsSysDdllError*); +extern int erts_sys_ddll_open2(const char *path, void **handle, ErtsSysDdllError*); #define erts_sys_ddll_open(P,H) erts_sys_ddll_open2(P,H,NULL) extern int erts_sys_ddll_open_noext(char *path, void **handle, ErtsSysDdllError*); extern int erts_sys_ddll_load_driver_init(void *handle, void **function); @@ -627,7 +627,7 @@ extern int erts_sys_ddll_close2(void *handle, ErtsSysDdllError*); #define erts_sys_ddll_close(H) erts_sys_ddll_close2(H,NULL) extern void *erts_sys_ddll_call_init(void *function); extern void *erts_sys_ddll_call_nif_init(void *function); -extern int erts_sys_ddll_sym2(void *handle, char *name, void **function, ErtsSysDdllError*); +extern int erts_sys_ddll_sym2(void *handle, const char *name, void **function, ErtsSysDdllError*); #define erts_sys_ddll_sym(H,N,F) erts_sys_ddll_sym2(H,N,F,NULL) extern char *erts_sys_ddll_error(int code); diff --git a/erts/emulator/sys/unix/erl_unix_sys_ddll.c b/erts/emulator/sys/unix/erl_unix_sys_ddll.c index 336d9586c4..a35aec560a 100644 --- a/erts/emulator/sys/unix/erl_unix_sys_ddll.c +++ b/erts/emulator/sys/unix/erl_unix_sys_ddll.c @@ -101,7 +101,7 @@ void erl_sys_ddll_init(void) { /* * Open a shared object */ -int erts_sys_ddll_open2(char *full_name, void **handle, ErtsSysDdllError* err) +int erts_sys_ddll_open2(const char *full_name, void **handle, ErtsSysDdllError* err) { #if defined(HAVE_DLOPEN) char* dlname; @@ -153,7 +153,7 @@ int erts_sys_ddll_open_noext(char *dlname, void **handle, ErtsSysDdllError* err) /* * Find a symbol in the shared object */ -int erts_sys_ddll_sym2(void *handle, char *func_name, void **function, +int erts_sys_ddll_sym2(void *handle, const char *func_name, void **function, ErtsSysDdllError* err) { #if defined(HAVE_DLOPEN) diff --git a/erts/emulator/sys/win32/erl_win32_sys_ddll.c b/erts/emulator/sys/win32/erl_win32_sys_ddll.c index d00eed932b..54991a610c 100644 --- a/erts/emulator/sys/win32/erl_win32_sys_ddll.c +++ b/erts/emulator/sys/win32/erl_win32_sys_ddll.c @@ -58,7 +58,7 @@ void erl_sys_ddll_init(void) { /* * Open a shared object */ -int erts_sys_ddll_open2(char *full_name, void **handle, ErtsSysDdllError* err) +int erts_sys_ddll_open2(const char *full_name, void **handle, ErtsSysDdllError* err) { int len; char dlname[MAXPATHLEN + 1]; @@ -92,7 +92,7 @@ int erts_sys_ddll_open_noext(char *dlname, void **handle, ErtsSysDdllError* err) /* * Find a symbol in the shared object */ -int erts_sys_ddll_sym2(void *handle, char *func_name, void **function, +int erts_sys_ddll_sym2(void *handle, const char *func_name, void **function, ErtsSysDdllError* err) { FARPROC proc; -- cgit v1.2.3