openssh/openssh-6.6.1p1-cisco-dh-ke...

55 lines
1.9 KiB
Diff

diff -up openssh-6.8p1/compat.c.cisco-dh openssh-6.8p1/compat.c
--- openssh-6.8p1/compat.c.cisco-dh 2015-03-17 06:49:20.000000000 +0100
+++ openssh-6.8p1/compat.c 2015-03-19 12:57:58.862606969 +0100
@@ -167,6 +167,7 @@ compat_datafellows(const char *version)
SSH_BUG_SCANNER },
{ "Probe-*",
SSH_BUG_PROBE },
+ { "Cisco-*", SSH_BUG_MAX4096DH },
{ NULL, 0 }
};
diff -up openssh-6.8p1/compat.h.cisco-dh openssh-6.8p1/compat.h
--- openssh-6.8p1/compat.h.cisco-dh 2015-03-17 06:49:20.000000000 +0100
+++ openssh-6.8p1/compat.h 2015-03-19 12:57:58.862606969 +0100
@@ -60,6 +60,7 @@
#define SSH_NEW_OPENSSH 0x04000000
#define SSH_BUG_DYNAMIC_RPORT 0x08000000
#define SSH_BUG_CURVE25519PAD 0x10000000
+#define SSH_BUG_MAX4096DH 0x20000000
void enable_compat13(void);
void enable_compat20(void);
diff -up openssh-6.8p1/kexgexc.c.cisco-dh openssh-6.8p1/kexgexc.c
--- openssh-6.8p1/kexgexc.c.cisco-dh 2015-03-19 12:57:58.862606969 +0100
+++ openssh-6.8p1/kexgexc.c 2015-03-19 13:11:52.320519969 +0100
@@ -64,8 +64,27 @@ kexgex_client(struct ssh *ssh)
kex->min = DH_GRP_MIN;
kex->max = DH_GRP_MAX;
+
+ /* Servers with MAX4096DH need a preferred size (nbits) <= 4096.
+ * We need to also ensure that min < nbits < max */
+
+ if (datafellows & SSH_BUG_MAX4096DH) {
+ /* The largest min for these servers is 4096 */
+ kex->min = MIN(kex->min, 4096);
+ }
+
kex->nbits = nbits;
- if (ssh->compat & SSH_OLD_DHGEX) {
+ kex->nbits = MIN(nbits, kex->max);
+ kex->nbits = MAX(nbits, kex->min);
+
+ if (ssh->compat & SSH_BUG_MAX4096DH) {
+ /* Cannot have a nbits > 4096 for these servers */
+ kex->nbits = MIN(kex->nbits, 4096);
+ /* nbits has to be powers of two */
+ if (kex->nbits == 3072)
+ kex->nbits = 4096;
+ }
+ if (ssh->compat & SSH_OLD_DHGEX) { /* Old GEX request */
/* Old GEX request */
if ((r = sshpkt_start(ssh, SSH2_MSG_KEX_DH_GEX_REQUEST_OLD))
!= 0 ||