X-Git-Url: http://andersk.mit.edu/gitweb/gssapi-openssh.git/blobdiff_plain/51f1e7024fd6e7881a0a713868d67861ba97fbfb..HEAD:/openssh/kexgexs.c

diff --git a/openssh/kexgexs.c b/openssh/kexgexs.c
index baebfcf..8515568 100644
--- a/openssh/kexgexs.c
+++ b/openssh/kexgexs.c
@@ -1,3 +1,4 @@
+/* $OpenBSD: kexgexs.c,v 1.12 2009/06/21 07:37:15 dtucker Exp $ */
 /*
  * Copyright (c) 2000 Niels Provos.  All rights reserved.
  * Copyright (c) 2001 Markus Friedl.  All rights reserved.
@@ -24,16 +25,27 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: kexgexs.c,v 1.1 2003/02/16 17:09:57 markus Exp $");
+
+#include <sys/param.h>
+
+#include <stdarg.h>
+#include <stdio.h>
+#include <string.h>
+#include <signal.h>
 
 #include "xmalloc.h"
+#include "buffer.h"
 #include "key.h"
+#include "cipher.h"
 #include "kex.h"
 #include "log.h"
 #include "packet.h"
 #include "dh.h"
 #include "ssh2.h"
 #include "compat.h"
+#ifdef GSSAPI
+#include "ssh-gss.h"
+#endif
 #include "monitor_wrap.h"
 
 void
@@ -43,8 +55,9 @@ kexgex_server(Kex *kex)
 	Key *server_host_key;
 	DH *dh;
 	u_char *kbuf, *hash, *signature = NULL, *server_host_key_blob = NULL;
-	u_int sbloblen, klen, kout, slen;
-	int min = -1, max = -1, nbits = -1, type;
+	u_int sbloblen, klen, slen, hashlen;
+	int omin = -1, min = -1, omax = -1, max = -1, onbits = -1, nbits = -1;
+	int type, kout;
 
 	if (kex->load_host_key == NULL)
 		fatal("Cannot load hostkey");
@@ -56,27 +69,29 @@ kexgex_server(Kex *kex)
 	switch (type) {
 	case SSH2_MSG_KEX_DH_GEX_REQUEST:
 		debug("SSH2_MSG_KEX_DH_GEX_REQUEST received");
-		min = packet_get_int();
-		nbits = packet_get_int();
-		max = packet_get_int();
+		omin = min = packet_get_int();
+		onbits = nbits = packet_get_int();
+		omax = max = packet_get_int();
 		min = MAX(DH_GRP_MIN, min);
 		max = MIN(DH_GRP_MAX, max);
+		nbits = MAX(DH_GRP_MIN, nbits);
+		nbits = MIN(DH_GRP_MAX, nbits);
 		break;
 	case SSH2_MSG_KEX_DH_GEX_REQUEST_OLD:
 		debug("SSH2_MSG_KEX_DH_GEX_REQUEST_OLD received");
-		nbits = packet_get_int();
-		min = DH_GRP_MIN;
-		max = DH_GRP_MAX;
+		onbits = nbits = packet_get_int();
 		/* unused for old GEX */
+		omin = min = DH_GRP_MIN;
+		omax = max = DH_GRP_MAX;
 		break;
 	default:
 		fatal("protocol error during kex, no DH_GEX_REQUEST: %d", type);
 	}
 	packet_check_eom();
 
-	if (max < min || nbits < min || max < nbits)
+	if (omax < omin || onbits < omin || omax < onbits)
 		fatal("DH_GEX_REQUEST, bad parameters: %d !< %d !< %d",
-		    min, nbits, max);
+		    omin, onbits, omax);
 
 	/* Contact privileged parent */
 	dh = PRIVSEP(choose_dh(min, nbits, max));
@@ -122,47 +137,51 @@ kexgex_server(Kex *kex)
 
 	klen = DH_size(dh);
 	kbuf = xmalloc(klen);
-	kout = DH_compute_key(kbuf, dh_client_pub, dh);
+	if ((kout = DH_compute_key(kbuf, dh_client_pub, dh)) < 0)
+		fatal("DH_compute_key: failed");
 #ifdef DEBUG_KEXDH
 	dump_digest("shared secret", kbuf, kout);
 #endif
 	if ((shared_secret = BN_new()) == NULL)
 		fatal("kexgex_server: BN_new failed");
-	BN_bin2bn(kbuf, kout, shared_secret);
+	if (BN_bin2bn(kbuf, kout, shared_secret) == NULL)
+		fatal("kexgex_server: BN_bin2bn failed");
 	memset(kbuf, 0, klen);
 	xfree(kbuf);
 
 	key_to_blob(server_host_key, &server_host_key_blob, &sbloblen);
 
 	if (type == SSH2_MSG_KEX_DH_GEX_REQUEST_OLD)
-		min = max = -1;
+		omin = min = omax = max = -1;
 
-	/* calc H */			/* XXX depends on 'kex' */
-	hash = kexgex_hash(
+	/* calc H */
+	kexgex_hash(
+	    kex->evp_md,
 	    kex->client_version_string,
 	    kex->server_version_string,
 	    buffer_ptr(&kex->peer), buffer_len(&kex->peer),
 	    buffer_ptr(&kex->my), buffer_len(&kex->my),
 	    server_host_key_blob, sbloblen,
-	    min, nbits, max,
+	    omin, onbits, omax,
 	    dh->p, dh->g,
 	    dh_client_pub,
 	    dh->pub_key,
-	    shared_secret
+	    shared_secret,
+	    &hash, &hashlen
 	);
 	BN_clear_free(dh_client_pub);
 
 	/* save session id := H */
-	/* XXX hashlen depends on KEX */
 	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);
 	}
 
 	/* sign H */
-	/* XXX hashlen depends on KEX */
-	PRIVSEP(key_sign(server_host_key, &signature, &slen, hash, 20));
+	if (PRIVSEP(key_sign(server_host_key, &signature, &slen, hash,
+	    hashlen)) < 0)
+		fatal("kexgex_server: key_sign failed");
 
 	/* destroy_sensitive_data(); */
 
@@ -179,7 +198,7 @@ kexgex_server(Kex *kex)
 	/* have keys, free DH */
 	DH_free(dh);
 
-	kex_derive_keys(kex, hash, shared_secret);
+	kex_derive_keys(kex, hash, hashlen, shared_secret);
 	BN_clear_free(shared_secret);
 
 	kex_finish(kex);