diff options
Diffstat (limited to 'src/libstrongswan/library.c')
| -rw-r--r-- | src/libstrongswan/library.c | 52 |
1 files changed, 51 insertions, 1 deletions
diff --git a/src/libstrongswan/library.c b/src/libstrongswan/library.c index 819c6808e..4dec61203 100644 --- a/src/libstrongswan/library.c +++ b/src/libstrongswan/library.c @@ -150,6 +150,51 @@ static bool equals(char *a, char *b) return streq(a, b); } +/** + * Write magic to memory, and try to clear it with memwipe() + */ +__attribute__((noinline)) +static void do_magic(int magic, int **stack) +{ + int buf[32], i; + + /* tell caller where callee stack is (but don't point to buf) */ + *stack = &i; + for (i = 0; i < countof(buf); i++) + { + buf[i] = magic; + } + /* passing buf to dbg should make sure the compiler can't optimize out buf. + * we use directly dbg(3), as DBG3() might be stripped with DEBUG_LEVEL. */ + dbg(DBG_LIB, 3, "memwipe() pre: %b", buf, sizeof(buf)); + memwipe(buf, sizeof(buf)); +} + +/** + * Check if memwipe works as expected + */ +static bool check_memwipe() +{ + int magic = 0xCAFEBABE, *ptr, *deeper, i, stackdir = 1; + + do_magic(magic, &deeper); + + ptr = &magic; + if (deeper < ptr) + { /* stack grows down */ + stackdir = -1; + } + for (i = 0; i < 128; i++) + { + ptr = ptr + stackdir; + if (*ptr == magic) + { + return FALSE; + } + } + return TRUE; +} + /* * see header file */ @@ -221,6 +266,12 @@ bool library_init(char *settings) this->public.scheduler = scheduler_create(); this->public.plugins = plugin_loader_create(); + if (!check_memwipe()) + { + DBG1(DBG_LIB, "memwipe() check failed"); + return FALSE; + } + if (lib->settings->get_bool(lib->settings, "libstrongswan.integrity_test", FALSE)) { @@ -239,4 +290,3 @@ bool library_init(char *settings) return !this->integrity_failed; } - |