diff options
Diffstat (limited to 'crypto/openssh/kexc25519s.c')
-rw-r--r-- | crypto/openssh/kexc25519s.c | 135 |
1 files changed, 84 insertions, 51 deletions
diff --git a/crypto/openssh/kexc25519s.c b/crypto/openssh/kexc25519s.c index 2b8e8ef..2402725 100644 --- a/crypto/openssh/kexc25519s.c +++ b/crypto/openssh/kexc25519s.c @@ -1,4 +1,4 @@ -/* $OpenBSD: kexc25519s.c,v 1.4 2014/01/12 08:13:13 djm Exp $ */ +/* $OpenBSD: kexc25519s.c,v 1.9 2015/04/27 00:37:53 dtucker Exp $ */ /* * Copyright (c) 2001 Markus Friedl. All rights reserved. * Copyright (c) 2010 Damien Miller. All rights reserved. @@ -27,100 +27,133 @@ #include "includes.h" #include <sys/types.h> +#include <stdio.h> #include <string.h> #include <signal.h> -#include "xmalloc.h" -#include "buffer.h" -#include "key.h" +#include "sshkey.h" #include "cipher.h" +#include "digest.h" #include "kex.h" #include "log.h" #include "packet.h" #include "ssh2.h" +#include "sshbuf.h" +#include "ssherr.h" -void -kexc25519_server(Kex *kex) +static int input_kex_c25519_init(int, u_int32_t, void *); + +int +kexc25519_server(struct ssh *ssh) +{ + debug("expecting SSH2_MSG_KEX_ECDH_INIT"); + ssh_dispatch_set(ssh, SSH2_MSG_KEX_ECDH_INIT, &input_kex_c25519_init); + return 0; +} + +static int +input_kex_c25519_init(int type, u_int32_t seq, void *ctxt) { - Key *server_host_private, *server_host_public; + struct ssh *ssh = ctxt; + struct kex *kex = ssh->kex; + struct sshkey *server_host_private, *server_host_public; + struct sshbuf *shared_secret = NULL; u_char *server_host_key_blob = NULL, *signature = NULL; u_char server_key[CURVE25519_SIZE]; u_char *client_pubkey = NULL; u_char server_pubkey[CURVE25519_SIZE]; - u_char *hash; - u_int slen, sbloblen, hashlen; - Buffer shared_secret; + u_char hash[SSH_DIGEST_MAX_LENGTH]; + size_t slen, pklen, sbloblen, hashlen; + int r; /* generate private key */ kexc25519_keygen(server_key, server_pubkey); #ifdef DEBUG_KEXECDH dump_digest("server private key:", server_key, sizeof(server_key)); #endif - if (kex->load_host_public_key == NULL || - kex->load_host_private_key == NULL) - fatal("Cannot load hostkey"); - server_host_public = kex->load_host_public_key(kex->hostkey_type); - if (server_host_public == NULL) - fatal("Unsupported hostkey type %d", kex->hostkey_type); - server_host_private = kex->load_host_private_key(kex->hostkey_type); - - debug("expecting SSH2_MSG_KEX_ECDH_INIT"); - packet_read_expect(SSH2_MSG_KEX_ECDH_INIT); - client_pubkey = packet_get_string(&slen); - if (slen != CURVE25519_SIZE) - fatal("Incorrect size for server Curve25519 pubkey: %d", slen); - packet_check_eom(); + kex->load_host_private_key == NULL) { + r = SSH_ERR_INVALID_ARGUMENT; + goto out; + } + server_host_public = kex->load_host_public_key(kex->hostkey_type, + kex->hostkey_nid, ssh); + server_host_private = kex->load_host_private_key(kex->hostkey_type, + kex->hostkey_nid, ssh); + if (server_host_public == NULL) { + r = SSH_ERR_NO_HOSTKEY_LOADED; + goto out; + } + if ((r = sshpkt_get_string(ssh, &client_pubkey, &pklen)) != 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("client public key:", client_pubkey, CURVE25519_SIZE); #endif - buffer_init(&shared_secret); - kexc25519_shared_key(server_key, client_pubkey, &shared_secret); + if ((shared_secret = sshbuf_new()) == NULL) { + r = SSH_ERR_ALLOC_FAIL; + goto out; + } + if ((r = kexc25519_shared_key(server_key, client_pubkey, + shared_secret)) < 0) + goto out; /* calc H */ - key_to_blob(server_host_public, &server_host_key_blob, &sbloblen); - kex_c25519_hash( + if ((r = sshkey_to_blob(server_host_public, &server_host_key_blob, + &sbloblen)) != 0) + goto out; + hashlen = sizeof(hash); + if ((r = kex_c25519_hash( kex->hash_alg, kex->client_version_string, kex->server_version_string, - buffer_ptr(&kex->peer), buffer_len(&kex->peer), - buffer_ptr(&kex->my), buffer_len(&kex->my), + sshbuf_ptr(kex->peer), sshbuf_len(kex->peer), + sshbuf_ptr(kex->my), sshbuf_len(kex->my), server_host_key_blob, sbloblen, client_pubkey, server_pubkey, - buffer_ptr(&shared_secret), buffer_len(&shared_secret), - &hash, &hashlen - ); + sshbuf_ptr(shared_secret), sshbuf_len(shared_secret), + hash, &hashlen)) < 0) + goto out; /* save session id := H */ 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); } /* sign H */ - kex->sign(server_host_private, server_host_public, &signature, &slen, - hash, hashlen); - - /* destroy_sensitive_data(); */ + if ((r = kex->sign(server_host_private, server_host_public, + &signature, &slen, hash, hashlen, ssh->compat)) < 0) + goto out; /* send server hostkey, ECDH pubkey 'Q_S' and signed H */ - packet_start(SSH2_MSG_KEX_ECDH_REPLY); - packet_put_string(server_host_key_blob, sbloblen); - packet_put_string(server_pubkey, sizeof(server_pubkey)); - packet_put_string(signature, slen); - packet_send(); - - free(signature); + if ((r = sshpkt_start(ssh, SSH2_MSG_KEX_ECDH_REPLY)) != 0 || + (r = sshpkt_put_string(ssh, server_host_key_blob, sbloblen)) != 0 || + (r = sshpkt_put_string(ssh, server_pubkey, sizeof(server_pubkey))) != 0 || + (r = sshpkt_put_string(ssh, signature, slen)) != 0 || + (r = sshpkt_send(ssh)) != 0) + goto out; + + if ((r = kex_derive_keys(ssh, hash, hashlen, shared_secret)) == 0) + r = kex_send_newkeys(ssh); +out: + explicit_bzero(hash, sizeof(hash)); + explicit_bzero(server_key, sizeof(server_key)); free(server_host_key_blob); - /* have keys, free server key */ + free(signature); free(client_pubkey); - - kex_derive_keys(kex, hash, hashlen, - buffer_ptr(&shared_secret), buffer_len(&shared_secret)); - buffer_free(&shared_secret); - kex_finish(kex); + sshbuf_free(shared_secret); + return r; } |