- (djm) [kexc25519.c kexc25519c.c kexc25519s.c] Import missed files from
KEX/curve25519 change
diff --git a/kexc25519.c b/kexc25519.c
new file mode 100644
index 0000000..348a7d5
--- /dev/null
+++ b/kexc25519.c
@@ -0,0 +1,127 @@
+/* $OpenBSD: kexc25519.c,v 1.2 2013/11/02 22:02:14 markus Exp $ */
+/*
+ * Copyright (c) 2001, 2013 Markus Friedl. All rights reserved.
+ * Copyright (c) 2010 Damien Miller. All rights reserved.
+ * Copyright (c) 2013 Aris Adamantiadis. 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 "includes.h"
+
+#include <sys/types.h>
+
+#include <signal.h>
+#include <string.h>
+
+#include <openssl/bn.h>
+#include <openssl/evp.h>
+
+#include "buffer.h"
+#include "ssh2.h"
+#include "key.h"
+#include "cipher.h"
+#include "kex.h"
+#include "log.h"
+
+extern int crypto_scalarmult_curve25519(u_char a[CURVE25519_SIZE],
+ const u_char b[CURVE25519_SIZE], const u_char c[CURVE25519_SIZE])
+ __attribute__((__bounded__(__minbytes__, 1, CURVE25519_SIZE)))
+ __attribute__((__bounded__(__minbytes__, 2, CURVE25519_SIZE)))
+ __attribute__((__bounded__(__minbytes__, 3, CURVE25519_SIZE)));
+
+void
+kexc25519_keygen(u_char key[CURVE25519_SIZE], u_char pub[CURVE25519_SIZE])
+{
+ static const u_char basepoint[CURVE25519_SIZE] = {9};
+
+ arc4random_buf(key, CURVE25519_SIZE);
+ crypto_scalarmult_curve25519(pub, key, basepoint);
+}
+
+BIGNUM *
+kexc25519_shared_key(const u_char key[CURVE25519_SIZE],
+ const u_char pub[CURVE25519_SIZE])
+{
+ u_char shared_key[CURVE25519_SIZE];
+ BIGNUM *shared_secret;
+
+ crypto_scalarmult_curve25519(shared_key, key, pub);
+#ifdef DEBUG_KEXECDH
+ dump_digest("shared secret", shared_key, CURVE25519_SIZE);
+#endif
+ if ((shared_secret = BN_new()) == NULL)
+ fatal("%s: BN_new failed", __func__);
+ if (BN_bin2bn(shared_key, sizeof(shared_key), shared_secret) == NULL)
+ fatal("%s: BN_bin2bn failed", __func__);
+ memset(shared_key, 0, CURVE25519_SIZE); /* XXX explicit_bzero() */
+ return (shared_secret);
+}
+
+void
+kex_c25519_hash(
+ const EVP_MD *evp_md,
+ char *client_version_string,
+ char *server_version_string,
+ char *ckexinit, int ckexinitlen,
+ char *skexinit, int skexinitlen,
+ u_char *serverhostkeyblob, int sbloblen,
+ const u_char client_dh_pub[CURVE25519_SIZE],
+ const u_char server_dh_pub[CURVE25519_SIZE],
+ 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_string(&b, client_dh_pub, CURVE25519_SIZE);
+ buffer_put_string(&b, server_dh_pub, CURVE25519_SIZE);
+ 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);
+}