libldap/tls.c calls CRYPTO_set_id_callback(ldap_pvt_thread_self), which

causes ldap_pvt_thread_self to be called with the wrong prototype.

That can cause OpenSSL to use a garbage value, e.g. if the unsigned
long it expects takes two words but ldap_pvt_thread_t is an int.

I'm fixing it in HEAD now and also provoking an error if unsigned
long cannot hold a ldap_pvt_thread_t.  Otherwise it can silently
compile to broken code.  Maybe the latter should go in configure,
but since OpenSSL presumably breaks anyway if that fails I don't
see much point at this time.

diff --git a/libraries/libldap/tls.c b/libraries/libldap/tls.c
index 99e252bb24018d3a8a8bb8e69f480c0bcdc004ac..ace10b7e3c6e4fbca39b6e550b8c782edd10424a 100644 (file)
--- a/libraries/libldap/tls.c
+++ b/libraries/libldap/tls.c
@@ -397,6 +397,24 @@ static void tls_locking_cb( int mode, int type, const char *file, int line )
        }
 }
 
+static unsigned long tls_thread_self( void )
+{
+       /* FIXME: CRYPTO_set_id_callback only works when ldap_pvt_thread_t
+        * is an integral type that fits in an unsigned long
+        */
+
+       /* force an error if ldap_pvt_thread_t is not such a type */
+       enum {
+               ok =
+               3 / (ldap_pvt_thread_t)2 == 1   /* integer */
+               && (ldap_pvt_thread_t)-1 > 0UL  /* not too wide signed */
+               && (ldap_pvt_thread_t)-2 < -1UL /* not too wide unsigned */
+       };
+       typedef struct { int dummy: ok ? 1 : -1; } Check[ok ? 1 : -1];
+
+       return ldap_pvt_thread_self();
+}
+
 static void tls_init_threads( void )
 {
        int i;
@@ -405,10 +423,7 @@ static void tls_init_threads( void )
                ldap_pvt_thread_mutex_init( &tls_mutexes[i] );
        }
        CRYPTO_set_locking_callback( tls_locking_cb );
-       CRYPTO_set_id_callback( ldap_pvt_thread_self );
-       /* FIXME: CRYPTO_set_id_callback only works when ldap_pvt_thread_t
-        * is an integral type that fits in an unsigned long
-        */
+       CRYPTO_set_id_callback( tls_thread_self );
 }
 #endif /* LDAP_R_COMPILE */