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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 14:40:04 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 14:40:04 +0000
commit25505898530a333011f4fd5cbc841ad6b26c089c (patch)
tree333a33fdd60930bcccc3f177ed9467d535e9bac6 /kexecdh.c
parentInitial commit. (diff)
downloadopenssh-25505898530a333011f4fd5cbc841ad6b26c089c.tar.xz
openssh-25505898530a333011f4fd5cbc841ad6b26c089c.zip
Adding upstream version 1:9.2p1.upstream/1%9.2p1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'kexecdh.c')
-rw-r--r--kexecdh.c239
1 files changed, 239 insertions, 0 deletions
diff --git a/kexecdh.c b/kexecdh.c
new file mode 100644
index 0000000..efb2e55
--- /dev/null
+++ b/kexecdh.c
@@ -0,0 +1,239 @@
+/* $OpenBSD: kexecdh.c,v 1.10 2019/01/21 10:40:11 djm Exp $ */
+/*
+ * Copyright (c) 2010 Damien Miller. All rights reserved.
+ * Copyright (c) 2019 Markus Friedl. 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"
+
+#if defined(WITH_OPENSSL) && defined(OPENSSL_HAS_ECC)
+
+#include <sys/types.h>
+
+#include <stdio.h>
+#include <string.h>
+#include <signal.h>
+
+#include <openssl/ecdh.h>
+
+#include "sshkey.h"
+#include "kex.h"
+#include "sshbuf.h"
+#include "digest.h"
+#include "ssherr.h"
+
+static int
+kex_ecdh_dec_key_group(struct kex *, const struct sshbuf *, EC_KEY *key,
+ const EC_GROUP *, struct sshbuf **);
+
+int
+kex_ecdh_keypair(struct kex *kex)
+{
+ EC_KEY *client_key = NULL;
+ const EC_GROUP *group;
+ const EC_POINT *public_key;
+ struct sshbuf *buf = NULL;
+ int r;
+
+ if ((client_key = EC_KEY_new_by_curve_name(kex->ec_nid)) == NULL) {
+ r = SSH_ERR_ALLOC_FAIL;
+ goto out;
+ }
+ if (EC_KEY_generate_key(client_key) != 1) {
+ r = SSH_ERR_LIBCRYPTO_ERROR;
+ goto out;
+ }
+ group = EC_KEY_get0_group(client_key);
+ public_key = EC_KEY_get0_public_key(client_key);
+
+ if ((buf = sshbuf_new()) == NULL) {
+ r = SSH_ERR_ALLOC_FAIL;
+ goto out;
+ }
+ if ((r = sshbuf_put_ec(buf, public_key, group)) != 0 ||
+ (r = sshbuf_get_u32(buf, NULL)) != 0)
+ goto out;
+#ifdef DEBUG_KEXECDH
+ fputs("client private key:\n", stderr);
+ sshkey_dump_ec_key(client_key);
+#endif
+ kex->ec_client_key = client_key;
+ kex->ec_group = group;
+ client_key = NULL; /* owned by the kex */
+ kex->client_pub = buf;
+ buf = NULL;
+ out:
+ EC_KEY_free(client_key);
+ sshbuf_free(buf);
+ return r;
+}
+
+int
+kex_ecdh_enc(struct kex *kex, const struct sshbuf *client_blob,
+ struct sshbuf **server_blobp, struct sshbuf **shared_secretp)
+{
+ const EC_GROUP *group;
+ const EC_POINT *pub_key;
+ EC_KEY *server_key = NULL;
+ struct sshbuf *server_blob = NULL;
+ int r;
+
+ *server_blobp = NULL;
+ *shared_secretp = NULL;
+
+ if ((server_key = EC_KEY_new_by_curve_name(kex->ec_nid)) == NULL) {
+ r = SSH_ERR_ALLOC_FAIL;
+ goto out;
+ }
+ if (EC_KEY_generate_key(server_key) != 1) {
+ r = SSH_ERR_LIBCRYPTO_ERROR;
+ goto out;
+ }
+ group = EC_KEY_get0_group(server_key);
+
+#ifdef DEBUG_KEXECDH
+ fputs("server private key:\n", stderr);
+ sshkey_dump_ec_key(server_key);
+#endif
+ pub_key = EC_KEY_get0_public_key(server_key);
+ if ((server_blob = sshbuf_new()) == NULL) {
+ r = SSH_ERR_ALLOC_FAIL;
+ goto out;
+ }
+ if ((r = sshbuf_put_ec(server_blob, pub_key, group)) != 0 ||
+ (r = sshbuf_get_u32(server_blob, NULL)) != 0)
+ goto out;
+ if ((r = kex_ecdh_dec_key_group(kex, client_blob, server_key, group,
+ shared_secretp)) != 0)
+ goto out;
+ *server_blobp = server_blob;
+ server_blob = NULL;
+ out:
+ EC_KEY_free(server_key);
+ sshbuf_free(server_blob);
+ return r;
+}
+
+static int
+kex_ecdh_dec_key_group(struct kex *kex, const struct sshbuf *ec_blob,
+ EC_KEY *key, const EC_GROUP *group, struct sshbuf **shared_secretp)
+{
+ struct sshbuf *buf = NULL;
+ BIGNUM *shared_secret = NULL;
+ EC_POINT *dh_pub = NULL;
+ u_char *kbuf = NULL;
+ size_t klen = 0;
+ int r;
+
+ *shared_secretp = NULL;
+
+ if ((buf = sshbuf_new()) == NULL) {
+ r = SSH_ERR_ALLOC_FAIL;
+ goto out;
+ }
+ if ((r = sshbuf_put_stringb(buf, ec_blob)) != 0)
+ goto out;
+ if ((dh_pub = EC_POINT_new(group)) == NULL) {
+ r = SSH_ERR_ALLOC_FAIL;
+ goto out;
+ }
+ if ((r = sshbuf_get_ec(buf, dh_pub, group)) != 0) {
+ goto out;
+ }
+ sshbuf_reset(buf);
+
+#ifdef DEBUG_KEXECDH
+ fputs("public key:\n", stderr);
+ sshkey_dump_ec_point(group, dh_pub);
+#endif
+ if (sshkey_ec_validate_public(group, dh_pub) != 0) {
+ r = SSH_ERR_MESSAGE_INCOMPLETE;
+ goto out;
+ }
+ klen = (EC_GROUP_get_degree(group) + 7) / 8;
+ if ((kbuf = malloc(klen)) == NULL ||
+ (shared_secret = BN_new()) == NULL) {
+ r = SSH_ERR_ALLOC_FAIL;
+ goto out;
+ }
+ if (ECDH_compute_key(kbuf, klen, dh_pub, key, NULL) != (int)klen ||
+ BN_bin2bn(kbuf, klen, shared_secret) == NULL) {
+ r = SSH_ERR_LIBCRYPTO_ERROR;
+ goto out;
+ }
+#ifdef DEBUG_KEXECDH
+ dump_digest("shared secret", kbuf, klen);
+#endif
+ if ((r = sshbuf_put_bignum2(buf, shared_secret)) != 0)
+ goto out;
+ *shared_secretp = buf;
+ buf = NULL;
+ out:
+ EC_POINT_clear_free(dh_pub);
+ BN_clear_free(shared_secret);
+ freezero(kbuf, klen);
+ sshbuf_free(buf);
+ return r;
+}
+
+int
+kex_ecdh_dec(struct kex *kex, const struct sshbuf *server_blob,
+ struct sshbuf **shared_secretp)
+{
+ int r;
+
+ r = kex_ecdh_dec_key_group(kex, server_blob, kex->ec_client_key,
+ kex->ec_group, shared_secretp);
+ EC_KEY_free(kex->ec_client_key);
+ kex->ec_client_key = NULL;
+ return r;
+}
+
+#else
+
+#include "ssherr.h"
+
+struct kex;
+struct sshbuf;
+struct sshkey;
+
+int
+kex_ecdh_keypair(struct kex *kex)
+{
+ return SSH_ERR_SIGN_ALG_UNSUPPORTED;
+}
+
+int
+kex_ecdh_enc(struct kex *kex, const struct sshbuf *client_blob,
+ struct sshbuf **server_blobp, struct sshbuf **shared_secretp)
+{
+ return SSH_ERR_SIGN_ALG_UNSUPPORTED;
+}
+
+int
+kex_ecdh_dec(struct kex *kex, const struct sshbuf *server_blob,
+ struct sshbuf **shared_secretp)
+{
+ return SSH_ERR_SIGN_ALG_UNSUPPORTED;
+}
+#endif /* defined(WITH_OPENSSL) && defined(OPENSSL_HAS_ECC) */