6 files changed, 28 insertions, 3 deletions

diff --git a/bufaux.c b/bufaux.c
index e24b5fc0a..f6a6f2ab2 100644
--- a/bufaux.c
+++ b/bufaux.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: bufaux.c,v 1.56 2014/02/02 03:44:31 djm Exp $ */
+/* $OpenBSD: bufaux.c,v 1.57 2014/04/16 23:22:45 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -372,6 +372,9 @@ buffer_put_bignum2_from_string(Buffer *buffer, const u_char *s, u_int l)
 
         if (l > 8 * 1024)
                 fatal("%s: length %u too long", __func__, l);
+        /* Skip leading zero bytes */
+        for (; l > 0 && *s == 0; l--, s++)
+                ;
         p = buf = xmalloc(l + 1);
         /*
          * If most significant bit is set then prepend a zero byte to
diff --git a/compat.c b/compat.c
index 9d9fabef3..2709dc5cf 100644
--- a/compat.c
+++ b/compat.c
@@ -95,6 +95,9 @@ compat_datafellows(const char *version)
                 { "Sun_SSH_1.0*",       SSH_BUG_NOREKEY|SSH_BUG_EXTEOF},
                 { "OpenSSH_4*",         0 },
                 { "OpenSSH_5*",         SSH_NEW_OPENSSH|SSH_BUG_DYNAMIC_RPORT},
+                { "OpenSSH_6.6.1*",     SSH_NEW_OPENSSH},
+                { "OpenSSH_6.5*,"
+                  "OpenSSH_6.6*",       SSH_NEW_OPENSSH|SSH_BUG_CURVE25519PAD},
                 { "OpenSSH*",           SSH_NEW_OPENSSH },
                 { "*MindTerm*",         0 },
                 { "2.1.0*",             SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
@@ -251,7 +254,6 @@ compat_cipher_proposal(char *cipher_prop)
         return cipher_prop;
 }
 
-
 char *
 compat_pkalg_proposal(char *pkalg_prop)
 {
@@ -265,3 +267,16 @@ compat_pkalg_proposal(char *pkalg_prop)
         return pkalg_prop;
 }
 
+char *
+compat_kex_proposal(char *kex_prop)
+{
+        if (!(datafellows & SSH_BUG_CURVE25519PAD))
+                return kex_prop;
+        debug2("%s: original KEX proposal: %s", __func__, kex_prop);
+        kex_prop = filter_proposal(kex_prop, "curve25519-sha256@libssh.org");
+        debug2("%s: compat KEX proposal: %s", __func__, kex_prop);
+        if (*kex_prop == '\0')
+                fatal("No supported key exchange algorithms found");
+        return kex_prop;
+}
+
diff --git a/compat.h b/compat.h
index b174fa171..a6c3f3d7a 100644
--- a/compat.h
+++ b/compat.h
@@ -59,6 +59,7 @@
 #define SSH_BUG_RFWD_ADDR       0x02000000
 #define SSH_NEW_OPENSSH         0x04000000
 #define SSH_BUG_DYNAMIC_RPORT   0x08000000
+#define SSH_BUG_CURVE25519PAD   0x10000000
 
 void     enable_compat13(void);
 void     enable_compat20(void);
@@ -66,6 +67,7 @@ void     compat_datafellows(const char *);
 int      proto_spec(const char *);
 char    *compat_cipher_proposal(char *);
 char    *compat_pkalg_proposal(char *);
+char    *compat_kex_proposal(char *);
 
 extern int compat13;
 extern int compat20;
diff --git a/sshconnect2.c b/sshconnect2.c
index 66cb03527..1a4e55179 100644
--- a/sshconnect2.c
+++ b/sshconnect2.c
@@ -220,6 +220,8 @@ ssh_kex2(char *host, struct sockaddr *hostaddr, u_short port)
         }
         if (options.kex_algorithms != NULL)
                 myproposal[PROPOSAL_KEX_ALGS] = options.kex_algorithms;
+        myproposal[PROPOSAL_KEX_ALGS] = compat_kex_proposal(
+            myproposal[PROPOSAL_KEX_ALGS]);
 
 #ifdef GSSAPI
         /* If we've got GSSAPI algorithms, then we also support the
diff --git a/sshd.c b/sshd.c
index 09644914c..fe78d7b66 100644
--- a/sshd.c
+++ b/sshd.c
@@ -2534,6 +2534,9 @@ do_ssh2_kex(void)
         if (options.kex_algorithms != NULL)
                 myproposal[PROPOSAL_KEX_ALGS] = options.kex_algorithms;
 
+        myproposal[PROPOSAL_KEX_ALGS] = compat_kex_proposal(
+            myproposal[PROPOSAL_KEX_ALGS]);
+
         if (options.rekey_limit || options.rekey_interval)
                 packet_set_rekey_limits((u_int32_t)options.rekey_limit,
                     (time_t)options.rekey_interval);
diff --git a/version.h b/version.h
index a97c337a3..065957661 100644
--- a/version.h
+++ b/version.h
@@ -1,6 +1,6 @@
 /* $OpenBSD: version.h,v 1.70 2014/02/27 22:57:40 djm Exp $ */
 
-#define SSH_VERSION     "OpenSSH_6.6"
+#define SSH_VERSION     "OpenSSH_6.6.1"
 
 #define SSH_PORTABLE    "p1"
 #define SSH_RELEASE_MINIMUM     SSH_VERSION SSH_PORTABLE