- djm@cvs.openbsd.org 2005/11/04 05:15:59
[kex.c kex.h kexdh.c kexdhc.c kexdhs.c kexgex.c kexgexc.c kexgexs.c]
remove hardcoded hash lengths in key exchange code, allowing
implementation of KEX methods with different hashes (e.g. SHA-256);
ok markus@ dtucker@ stevesk@
diff --git a/kexdhc.c b/kexdhc.c
index f48bd46..d8a2fa3 100644
--- a/kexdhc.c
+++ b/kexdhc.c
@@ -23,7 +23,7 @@
*/
#include "includes.h"
-RCSID("$OpenBSD: kexdhc.c,v 1.2 2004/06/13 12:53:24 djm Exp $");
+RCSID("$OpenBSD: kexdhc.c,v 1.3 2005/11/04 05:15:59 djm Exp $");
#include "xmalloc.h"
#include "key.h"
@@ -41,7 +41,7 @@
Key *server_host_key;
u_char *server_host_key_blob = NULL, *signature = NULL;
u_char *kbuf, *hash;
- u_int klen, kout, slen, sbloblen;
+ u_int klen, kout, slen, sbloblen, hashlen;
/* generate and send 'e', client DH public key */
switch (kex->kex_type) {
@@ -114,7 +114,7 @@
xfree(kbuf);
/* calc and verify H */
- hash = kex_dh_hash(
+ kex_dh_hash(
kex->client_version_string,
kex->server_version_string,
buffer_ptr(&kex->my), buffer_len(&kex->my),
@@ -122,25 +122,26 @@
server_host_key_blob, sbloblen,
dh->pub_key,
dh_server_pub,
- shared_secret
+ shared_secret,
+ &hash, &hashlen
);
xfree(server_host_key_blob);
BN_clear_free(dh_server_pub);
DH_free(dh);
- if (key_verify(server_host_key, signature, slen, hash, 20) != 1)
+ if (key_verify(server_host_key, signature, slen, hash, hashlen) != 1)
fatal("key_verify failed for server_host_key");
key_free(server_host_key);
xfree(signature);
/* save session id */
if (kex->session_id == NULL) {
- kex->session_id_len = 20;
+ kex->session_id_len = hashlen;
kex->session_id = xmalloc(kex->session_id_len);
memcpy(kex->session_id, hash, kex->session_id_len);
}
- kex_derive_keys(kex, hash, shared_secret);
+ kex_derive_keys(kex, hash, hashlen, shared_secret);
BN_clear_free(shared_secret);
kex_finish(kex);
}