refactor SSH MAC

1 files changed, 82 insertions, 0 deletions

diff --git a/src/protocol/internal/ssh_mac.c b/src/protocol/internal/ssh_mac.c
new file mode 100644
index 0000000..2062cff
--- /dev/null
+++ b/src/protocol/internal/ssh_mac.c
@@ -0,0 +1,82 @@
+/*
+ * ssh_mac.c: the MAC algorithms used in SSH
+ * Copyright (C) 2018  Iru Cai <mytbk920423@gmail.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#include "ssh_mac.h"
+#include "ssh_crypto_common.h"
+#include <stdlib.h>
+#include <openssl/evp.h>
+#include <openssl/hmac.h>
+
+static struct ssh_mac_t *new_evp_mac(const struct ssh_mac_t *t)
+{
+	struct ssh_mac_t *m = (struct ssh_mac_t *)malloc(sizeof(struct ssh_mac_t));
+	const EVP_MD *evp_md = ((const EVP_MD *(*)(void))(t->priv))();
+	*m = *t;
+	m->priv = evp_md;
+	return m;
+}
+
+static void free_evp_mac(struct ssh_mac_t *m)
+{
+	free(m);
+}
+
+static void get_evp_digest(SSH_MAC *my, const unsigned char *d, int len, unsigned char *dgst)
+{
+	unsigned int tmp;
+	HMAC((const EVP_MD *)(my->priv), my->key, my->keySize, d, len, dgst, &tmp);
+}
+
+/* RFC 6668 */
+struct ssh_mac_t hmac_sha2_256 = {
+	.name = "hmac-sha2-256",
+	.priv = (void*)EVP_sha256,
+	.new_mac = new_evp_mac,
+	.cleanup = free_evp_mac,
+	.getmac = get_evp_digest,
+	.dgstSize = 32,
+	.keySize = 32
+};
+
+struct ssh_mac_t hmac_sha1 = {
+	.name = "hmac-sha1",
+	.priv = (void*)EVP_sha1,
+	.new_mac = new_evp_mac,
+	.cleanup = free_evp_mac,
+	.getmac = get_evp_digest,
+	.dgstSize = 20,
+	.keySize = 20
+};
+
+static name_list all_macs = {
+	{ "hmac-sha2-256", &hmac_sha2_256 },
+	{ "hmac-sha1", &hmac_sha1 },
+	{ NULL, NULL }
+};
+
+const struct ssh_mac_t * search_mac(const char *s)
+{
+	int i = search_name(all_macs, s);
+	if (i!=-1)
+		return all_macs[i].f;
+	else
+		return NULL;
+}
+
+const char all_macs_list[] = "hmac-sha2-256,hmac-sha1";