diff options
author | Phil Pennock <pdp@exim.org> | 2012-05-17 01:32:13 -0400 |
---|---|---|
committer | Phil Pennock <pdp@exim.org> | 2012-05-17 01:32:13 -0400 |
commit | af3498d60d7cae92d50e56353ae19f304b84e6ca (patch) | |
tree | 7c7d4f0ff32504ed7eda563767dd96e190e5fedc /src | |
parent | eae0036b2dfac1547351908f77a6154b898c45d6 (diff) |
Guards for older releases of GnuTLS.
gnutls_sec_param_to_pk_bits() and gnutls_rnd() are both new as of
GnuTLS 2.12.x. Guard their usage on 2.12.0+ at compile time.
In older versions, the vaguely_random_number() function just immediately
calls the fallback, so it's the same as before this change (just one
extra indirection in the code-path).
Define a constant of 1024 for dh-bits for use in those old releases
where GnuTLS won't tell us how many we should use.
Change the on-disk filename for generated D-H params again, replacing
the -normal with -<bitcount>, so that it's 1024 or whatever, and as
the value changes, Exim will automatically start using the new value.
Diffstat (limited to 'src')
-rw-r--r-- | src/src/tls-gnu.c | 53 |
1 files changed, 44 insertions, 9 deletions
diff --git a/src/src/tls-gnu.c b/src/src/tls-gnu.c index f0e391f97..6dd76cd40 100644 --- a/src/src/tls-gnu.c +++ b/src/src/tls-gnu.c @@ -141,12 +141,6 @@ static BOOL exim_gnutls_base_init_done = FALSE; /* ------------------------------------------------------------------------ */ -/* Callback declarations */ - -static void exim_gnutls_logger_cb(int level, const char *message); -static int exim_sni_handling_cb(gnutls_session_t session); - -/* ------------------------------------------------------------------------ */ /* macros */ #define MAX_HOST_LEN 255 @@ -158,6 +152,11 @@ callbacks. */ #define EXIM_CLIENT_DH_MIN_BITS 1024 +/* With GnuTLS 2.12.x+ we have gnutls_sec_param_to_pk_bits() with which we +can ask for a bit-strength. Without that, we stick to the constant we had +before, for now. */ +#define EXIM_SERVER_DH_BITS_PRE2_12 1024 + #define exim_gnutls_err_check(Label) do { \ if (rc != GNUTLS_E_SUCCESS) { return tls_error((Label), gnutls_strerror(rc), host); } } while (0) @@ -170,8 +169,25 @@ callbacks. */ #if GNUTLS_VERSION_NUMBER >= 0x020c00 #define HAVE_GNUTLS_SESSION_CHANNEL_BINDING +#define HAVE_GNUTLS_SEC_PARAM_CONSTANTS +#define HAVE_GNUTLS_RND #endif + + + +/* ------------------------------------------------------------------------ */ +/* Callback declarations */ + +#if EXIM_GNUTLS_LIBRARY_LOG_LEVEL >= 0 +static void exim_gnutls_logger_cb(int level, const char *message); +#endif + +static int exim_sni_handling_cb(gnutls_session_t session); + + + + /* ------------------------------------------------------------------------ */ /* Static functions */ @@ -380,21 +396,30 @@ gnutls_datum m; uschar filename[PATH_MAX]; size_t sz; host_item *host = NULL; /* dummy for macros */ -const char * const dh_param_fn_ext = "normal"; /* change as dh_bits changes */ DEBUG(D_tls) debug_printf("Initialising GnuTLS server params.\n"); rc = gnutls_dh_params_init(&dh_server_params); exim_gnutls_err_check(US"gnutls_dh_params_init"); -/* If you change this, also change dh_param_fn_ext so that we can use a +#ifdef HAVE_GNUTLS_SEC_PARAM_CONSTANTS +/* If you change this constant, also change dh_param_fn_ext so that we can use a different filename and ensure we have sufficient bits. */ dh_bits = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, GNUTLS_SEC_PARAM_NORMAL); if (!dh_bits) return tls_error(US"gnutls_sec_param_to_pk_bits() failed", NULL, NULL); +DEBUG(D_tls) + debug_printf("GnuTLS tells us that for D-H PL, NORMAL is %d bits.\n", + dh_bits); +#else +dh_bits = EXIM_SERVER_DH_BITS_PRE2_12; +DEBUG(D_tls) + debug_printf("GnuTLS lacks gnutls_sec_param_to_pk_bits(), using %d bits.\n", + dh_bits); +#endif if (!string_format(filename, sizeof(filename), - "%s/gnutls-params-%s", spool_directory, dh_param_fn_ext)) + "%s/gnutls-params-%d", spool_directory, dh_bits)) return tls_error(US"overlong filename", NULL, NULL); /* Open the cache file for reading and if successful, read it and set up the @@ -1095,11 +1120,13 @@ return TRUE; * gnutls_global_set_log_function() * gnutls_global_set_log_level() 0..9 */ +#if EXIM_GNUTLS_LIBRARY_LOG_LEVEL >= 0 static void exim_gnutls_logger_cb(int level, const char *message) { DEBUG(D_tls) debug_printf("GnuTLS<%d>: %s\n", level, message); } +#endif /* Called after client hello, should handle SNI work. @@ -1667,6 +1694,7 @@ Arguments: Returns a random number in range [0, max-1] */ +#ifdef HAVE_GNUTLS_RND int vaguely_random_number(int max) { @@ -1704,6 +1732,13 @@ for (p = smallbuf; needed_len; --needed_len, ++p) * smooth distribution and cares enough then they should submit a patch then. */ return r % max; } +#else /* HAVE_GNUTLS_RND */ +int +vaguely_random_number(int max) +{ + return vaguely_random_number_fallback(max); +} +#endif /* HAVE_GNUTLS_RND */ |