1 files changed, 108 insertions, 0 deletions

diff --git a/kexecdh.c b/kexecdh.c
new file mode 100644
index 000000000..a5a14f4bd
--- /dev/null
+++ b/kexecdh.c
@@ -0,0 +1,108 @@
+/* $OpenBSD: kexecdh.c,v 1.1 2010/08/31 11:54:45 djm Exp $ */
+/*
+ * Copyright (c) 2001 Markus Friedl.  All rights reserved.
+ * Copyright (c) 2010 Damien Miller.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/types.h>
+
+#include <signal.h>
+#include <string.h>
+
+#include <openssl/bn.h>
+#include <openssl/evp.h>
+#include <openssl/ec.h>
+#include <openssl/ecdh.h>
+
+#include "buffer.h"
+#include "ssh2.h"
+#include "key.h"
+#include "cipher.h"
+#include "kex.h"
+#include "log.h"
+
+int
+kex_ecdh_name_to_nid(const char *kexname)
+{
+        int ret;
+
+        if (strlen(kexname) < sizeof(KEX_ECDH_SHA256) - 1)
+                fatal("%s: kexname too short \"%s\"", __func__, kexname);
+        ret = key_curve_name_to_nid(kexname + sizeof(KEX_ECDH_SHA256) - 1);
+        if (ret == -1)
+                fatal("%s: unsupported curve negotiated \"%s\"", __func__,
+                    kexname);
+        return ret;
+}
+
+void
+kex_ecdh_hash(
+    const EVP_MD *evp_md,
+    const EC_GROUP *ec_group,
+    char *client_version_string,
+    char *server_version_string,
+    char *ckexinit, int ckexinitlen,
+    char *skexinit, int skexinitlen,
+    u_char *serverhostkeyblob, int sbloblen,
+    const EC_POINT *client_dh_pub,
+    const EC_POINT *server_dh_pub,
+    const BIGNUM *shared_secret,
+    u_char **hash, u_int *hashlen)
+{
+        Buffer b;
+        EVP_MD_CTX md;
+        static u_char digest[EVP_MAX_MD_SIZE];
+
+        buffer_init(&b);
+        buffer_put_cstring(&b, client_version_string);
+        buffer_put_cstring(&b, server_version_string);
+
+        /* kexinit messages: fake header: len+SSH2_MSG_KEXINIT */
+        buffer_put_int(&b, ckexinitlen+1);
+        buffer_put_char(&b, SSH2_MSG_KEXINIT);
+        buffer_append(&b, ckexinit, ckexinitlen);
+        buffer_put_int(&b, skexinitlen+1);
+        buffer_put_char(&b, SSH2_MSG_KEXINIT);
+        buffer_append(&b, skexinit, skexinitlen);
+
+        buffer_put_string(&b, serverhostkeyblob, sbloblen);
+        buffer_put_ecpoint(&b, ec_group, client_dh_pub);
+        buffer_put_ecpoint(&b, ec_group, server_dh_pub);
+        buffer_put_bignum2(&b, shared_secret);
+
+#ifdef DEBUG_KEX
+        buffer_dump(&b);
+#endif
+        EVP_DigestInit(&md, evp_md);
+        EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b));
+        EVP_DigestFinal(&md, digest, NULL);
+
+        buffer_free(&b);
+
+#ifdef DEBUG_KEX
+        dump_digest("hash", digest, EVP_MD_size(evp_md));
+#endif
+        *hash = digest;
+        *hashlen = EVP_MD_size(evp_md);
+}
+