You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

174 lines
5.0 KiB

diff --git a/modules/ssl/ssl_engine_init.c b/modules/ssl/ssl_engine_init.c
index 46769e9..0275452 100644
--- a/modules/ssl/ssl_engine_init.c
+++ b/modules/ssl/ssl_engine_init.c
@@ -41,6 +41,79 @@
#define KEYTYPES "RSA or DSA"
#endif
+/*
+ * Grab well-defined DH parameters from OpenSSL, see the get_rfc*
+ * functions in <openssl/bn.h> for all available primes.
+ */
+static DH *make_dh_params(BIGNUM *(*prime)(BIGNUM *), const char *gen)
+{
+ DH *dh = DH_new();
+
+ if (!dh) {
+ return NULL;
+ }
+ dh->p = prime(NULL);
+ BN_dec2bn(&dh->g, gen);
+ if (!dh->p || !dh->g) {
+ DH_free(dh);
+ return NULL;
+ }
+ return dh;
+}
+
+/* Storage and initialization for DH parameters. */
+static struct dhparam {
+ BIGNUM *(*const prime)(BIGNUM *); /* function to generate... */
+ DH *dh; /* ...this, used for keys.... */
+ const unsigned int min; /* ...of length >= this. */
+} dhparams[] = {
+ { get_rfc3526_prime_8192, NULL, 6145 },
+ { get_rfc3526_prime_6144, NULL, 4097 },
+ { get_rfc3526_prime_4096, NULL, 3073 },
+ { get_rfc3526_prime_3072, NULL, 2049 },
+ { get_rfc3526_prime_2048, NULL, 1025 },
+ { get_rfc2409_prime_1024, NULL, 0 }
+};
+
+static void init_dh_params(void)
+{
+ unsigned n;
+
+ for (n = 0; n < sizeof(dhparams)/sizeof(dhparams[0]); n++)
+ dhparams[n].dh = make_dh_params(dhparams[n].prime, "2");
+}
+
+static void free_dh_params(void)
+{
+ unsigned n;
+
+ /* DH_free() is a noop for a NULL parameter, so these are harmless
+ * in the (unexpected) case where these variables are already
+ * NULL. */
+ for (n = 0; n < sizeof(dhparams)/sizeof(dhparams[0]); n++) {
+ DH_free(dhparams[n].dh);
+ dhparams[n].dh = NULL;
+ }
+}
+
+/* Hand out the same DH structure though once generated as we leak
+ * memory otherwise and freeing the structure up after use would be
+ * hard to track and in fact is not needed at all as it is safe to
+ * use the same parameters over and over again security wise (in
+ * contrast to the keys itself) and code safe as the returned structure
+ * is duplicated by OpenSSL anyway. Hence no modification happens
+ * to our copy. */
+DH *modssl_get_dh_params(unsigned keylen)
+{
+ unsigned n;
+
+ for (n = 0; n < sizeof(dhparams)/sizeof(dhparams[0]); n++)
+ if (keylen >= dhparams[n].min)
+ return dhparams[n].dh;
+
+ return NULL; /* impossible to reach. */
+}
+
static void ssl_add_version_components(apr_pool_t *p,
server_rec *s)
{
@@ -244,6 +317,8 @@ int ssl_init_Module(apr_pool_t *p, apr_pool_t *plog,
SSL_init_app_data2_idx(); /* for SSL_get_app_data2() at request time */
+ init_dh_params();
+
return OK;
}
@@ -1623,6 +1698,8 @@ apr_status_t ssl_init_ModuleKill(void *data)
ssl_init_ctx_cleanup_server(sc->server);
}
+ free_dh_params();
+
return APR_SUCCESS;
}
diff --git a/modules/ssl/ssl_engine_kernel.c b/modules/ssl/ssl_engine_kernel.c
index 2d6d59e..1ecbccd 100644
--- a/modules/ssl/ssl_engine_kernel.c
+++ b/modules/ssl/ssl_engine_kernel.c
@@ -1287,34 +1287,6 @@ const authz_provider ssl_authz_provider_verify_client =
*/
/*
- * Grab well-defined DH parameters from OpenSSL, see <openssl/bn.h>
- * (get_rfc*) for all available primes.
- */
-#define make_get_dh(rfc,size,gen) \
-static DH *get_dh##size(void) \
-{ \
- DH *dh; \
- if (!(dh = DH_new())) { \
- return NULL; \
- } \
- dh->p = get_##rfc##_prime_##size(NULL); \
- BN_dec2bn(&dh->g, #gen); \
- if (!dh->p || !dh->g) { \
- DH_free(dh); \
- return NULL; \
- } \
- return dh; \
-}
-
-/*
- * Prepare DH parameters from 1024 to 4096 bits, in 1024-bit increments
- */
-make_get_dh(rfc2409, 1024, 2)
-make_get_dh(rfc3526, 2048, 2)
-make_get_dh(rfc3526, 3072, 2)
-make_get_dh(rfc3526, 4096, 2)
-
-/*
* Hand out standard DH parameters, based on the authentication strength
*/
DH *ssl_callback_TmpDH(SSL *ssl, int export, int keylen)
@@ -1342,14 +1314,7 @@ DH *ssl_callback_TmpDH(SSL *ssl, int export, int keylen)
ap_log_cerror(APLOG_MARK, APLOG_TRACE2, 0, c,
"handing out built-in DH parameters for %d-bit authenticated connection", keylen);
- if (keylen >= 4096)
- return get_dh4096();
- else if (keylen >= 3072)
- return get_dh3072();
- else if (keylen >= 2048)
- return get_dh2048();
- else
- return get_dh1024();
+ return modssl_get_dh_params(keylen);
}
/*
diff --git a/modules/ssl/ssl_private.h b/modules/ssl/ssl_private.h
index 744af9e..f47ed47 100644
--- a/modules/ssl/ssl_private.h
+++ b/modules/ssl/ssl_private.h
@@ -990,6 +990,11 @@ OCSP_RESPONSE *modssl_dispatch_ocsp_request(const apr_uri_t *uri,
conn_rec *c, apr_pool_t *p);
#endif
+/* Retrieve DH parameters for given key length. Return value should
+ * be treated as unmutable, since it is stored in process-global
+ * memory. */
+DH *modssl_get_dh_params(unsigned keylen);
+
#endif /* SSL_PRIVATE_H */
/** @} */