-/* $OpenBSD: kexc25519c.c,v 1.4 2014/01/12 08:13:13 djm Exp $ */
+/* $OpenBSD: kexc25519c.c,v 1.9 2017/12/18 02:25:15 djm Exp $ */
/*
* Copyright (c) 2001 Markus Friedl. All rights reserved.
* Copyright (c) 2010 Damien Miller. All rights reserved.
#include <string.h>
#include <signal.h>
-#include "xmalloc.h"
-#include "buffer.h"
-#include "key.h"
+#include "sshkey.h"
#include "cipher.h"
#include "kex.h"
#include "log.h"
#include "packet.h"
#include "ssh2.h"
+#include "sshbuf.h"
+#include "digest.h"
+#include "ssherr.h"
-void
-kexc25519_client(Kex *kex)
-{
- Key *server_host_key;
- u_char client_key[CURVE25519_SIZE];
- u_char client_pubkey[CURVE25519_SIZE];
- u_char *server_pubkey = NULL;
- u_char *server_host_key_blob = NULL, *signature = NULL;
- u_char *hash;
- u_int slen, sbloblen, hashlen;
- Buffer shared_secret;
-
- kexc25519_keygen(client_key, client_pubkey);
+static int
+input_kex_c25519_reply(int type, u_int32_t seq, struct ssh *ssh);
- packet_start(SSH2_MSG_KEX_ECDH_INIT);
- packet_put_string(client_pubkey, sizeof(client_pubkey));
- packet_send();
- debug("sending SSH2_MSG_KEX_ECDH_INIT");
+int
+kexc25519_client(struct ssh *ssh)
+{
+ struct kex *kex = ssh->kex;
+ int r;
+ kexc25519_keygen(kex->c25519_client_key, kex->c25519_client_pubkey);
#ifdef DEBUG_KEXECDH
- dump_digest("client private key:", client_key, sizeof(client_key));
+ dump_digest("client private key:", kex->c25519_client_key,
+ sizeof(kex->c25519_client_key));
#endif
+ if ((r = sshpkt_start(ssh, SSH2_MSG_KEX_ECDH_INIT)) != 0 ||
+ (r = sshpkt_put_string(ssh, kex->c25519_client_pubkey,
+ sizeof(kex->c25519_client_pubkey))) != 0 ||
+ (r = sshpkt_send(ssh)) != 0)
+ return r;
debug("expecting SSH2_MSG_KEX_ECDH_REPLY");
- packet_read_expect(SSH2_MSG_KEX_ECDH_REPLY);
+ ssh_dispatch_set(ssh, SSH2_MSG_KEX_ECDH_REPLY, &input_kex_c25519_reply);
+ return 0;
+}
+
+static int
+input_kex_c25519_reply(int type, u_int32_t seq, struct ssh *ssh)
+{
+ struct kex *kex = ssh->kex;
+ struct sshkey *server_host_key = NULL;
+ struct sshbuf *shared_secret = NULL;
+ u_char *server_pubkey = NULL;
+ u_char *server_host_key_blob = NULL, *signature = NULL;
+ u_char hash[SSH_DIGEST_MAX_LENGTH];
+ size_t slen, pklen, sbloblen, hashlen;
+ int r;
+
+ if (kex->verify_host_key == NULL) {
+ r = SSH_ERR_INVALID_ARGUMENT;
+ goto out;
+ }
/* hostkey */
- server_host_key_blob = packet_get_string(&sbloblen);
- server_host_key = key_from_blob(server_host_key_blob, sbloblen);
- if (server_host_key == NULL)
- fatal("cannot decode server_host_key_blob");
- if (server_host_key->type != kex->hostkey_type)
- fatal("type mismatch for decoded server_host_key_blob");
- if (kex->verify_host_key == NULL)
- fatal("cannot verify server_host_key");
- if (kex->verify_host_key(server_host_key) == -1)
- fatal("server_host_key verification failed");
+ if ((r = sshpkt_get_string(ssh, &server_host_key_blob,
+ &sbloblen)) != 0 ||
+ (r = sshkey_from_blob(server_host_key_blob, sbloblen,
+ &server_host_key)) != 0)
+ goto out;
+ if (server_host_key->type != kex->hostkey_type ||
+ (kex->hostkey_type == KEY_ECDSA &&
+ server_host_key->ecdsa_nid != kex->hostkey_nid)) {
+ r = SSH_ERR_KEY_TYPE_MISMATCH;
+ goto out;
+ }
+ if (kex->verify_host_key(server_host_key, ssh) == -1) {
+ r = SSH_ERR_SIGNATURE_INVALID;
+ goto out;
+ }
/* Q_S, server public key */
- server_pubkey = packet_get_string(&slen);
- if (slen != CURVE25519_SIZE)
- fatal("Incorrect size for server Curve25519 pubkey: %d", slen);
+ /* signed H */
+ if ((r = sshpkt_get_string(ssh, &server_pubkey, &pklen)) != 0 ||
+ (r = sshpkt_get_string(ssh, &signature, &slen)) != 0 ||
+ (r = sshpkt_get_end(ssh)) != 0)
+ goto out;
+ if (pklen != CURVE25519_SIZE) {
+ r = SSH_ERR_SIGNATURE_INVALID;
+ goto out;
+ }
#ifdef DEBUG_KEXECDH
dump_digest("server public key:", server_pubkey, CURVE25519_SIZE);
#endif
- /* signed H */
- signature = packet_get_string(&slen);
- packet_check_eom();
-
- buffer_init(&shared_secret);
- kexc25519_shared_key(client_key, server_pubkey, &shared_secret);
+ if ((shared_secret = sshbuf_new()) == NULL) {
+ r = SSH_ERR_ALLOC_FAIL;
+ goto out;
+ }
+ if ((r = kexc25519_shared_key(kex->c25519_client_key, server_pubkey,
+ shared_secret)) < 0)
+ goto out;
/* calc and verify H */
- kex_c25519_hash(
+ hashlen = sizeof(hash);
+ if ((r = kex_c25519_hash(
kex->hash_alg,
kex->client_version_string,
kex->server_version_string,
- buffer_ptr(&kex->my), buffer_len(&kex->my),
- buffer_ptr(&kex->peer), buffer_len(&kex->peer),
+ sshbuf_ptr(kex->my), sshbuf_len(kex->my),
+ sshbuf_ptr(kex->peer), sshbuf_len(kex->peer),
server_host_key_blob, sbloblen,
- client_pubkey,
+ kex->c25519_client_pubkey,
server_pubkey,
- buffer_ptr(&shared_secret), buffer_len(&shared_secret),
- &hash, &hashlen
- );
- free(server_host_key_blob);
- free(server_pubkey);
- if (key_verify(server_host_key, signature, slen, hash, hashlen) != 1)
- fatal("key_verify failed for server_host_key");
- key_free(server_host_key);
- free(signature);
+ sshbuf_ptr(shared_secret), sshbuf_len(shared_secret),
+ hash, &hashlen)) < 0)
+ goto out;
+
+ if ((r = sshkey_verify(server_host_key, signature, slen, hash, hashlen,
+ kex->hostkey_alg, ssh->compat)) != 0)
+ goto out;
/* save session id */
if (kex->session_id == NULL) {
kex->session_id_len = hashlen;
- kex->session_id = xmalloc(kex->session_id_len);
+ kex->session_id = malloc(kex->session_id_len);
+ if (kex->session_id == NULL) {
+ r = SSH_ERR_ALLOC_FAIL;
+ goto out;
+ }
memcpy(kex->session_id, hash, kex->session_id_len);
}
- kex_derive_keys(kex, hash, hashlen,
- buffer_ptr(&shared_secret), buffer_len(&shared_secret));
- buffer_free(&shared_secret);
- kex_finish(kex);
+
+ if ((r = kex_derive_keys(ssh, hash, hashlen, shared_secret)) == 0)
+ r = kex_send_newkeys(ssh);
+out:
+ explicit_bzero(hash, sizeof(hash));
+ explicit_bzero(kex->c25519_client_key, sizeof(kex->c25519_client_key));
+ free(server_host_key_blob);
+ free(server_pubkey);
+ free(signature);
+ sshkey_free(server_host_key);
+ sshbuf_free(shared_secret);
+ return r;
}
projects / platform / upstream / openssh.git / blobdiff