1 /* $OpenBSD: kex.h,v 1.76 2016/02/08 10:57:07 djm Exp $ */
4 * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 #include "buffer.h" /* XXX for typedef */
31 #include "key.h" /* XXX for typedef */
33 #ifdef WITH_LEAKMALLOC
34 #include "leakmalloc.h"
38 # ifdef OPENSSL_HAS_ECC
39 # include <openssl/ec.h>
40 # else /* OPENSSL_HAS_ECC */
42 # define EC_GROUP void
43 # define EC_POINT void
44 # endif /* OPENSSL_HAS_ECC */
45 #else /* WITH_OPENSSL */
47 # define EC_GROUP void
48 # define EC_POINT void
49 #endif /* WITH_OPENSSL */
51 #define KEX_COOKIE_LEN 16
53 #define KEX_DH1 "diffie-hellman-group1-sha1"
54 #define KEX_DH14 "diffie-hellman-group14-sha1"
55 #define KEX_DHGEX_SHA1 "diffie-hellman-group-exchange-sha1"
56 #define KEX_DHGEX_SHA256 "diffie-hellman-group-exchange-sha256"
57 #define KEX_ECDH_SHA2_NISTP256 "ecdh-sha2-nistp256"
58 #define KEX_ECDH_SHA2_NISTP384 "ecdh-sha2-nistp384"
59 #define KEX_ECDH_SHA2_NISTP521 "ecdh-sha2-nistp521"
60 #define KEX_CURVE25519_SHA256 "curve25519-sha256@libssh.org"
64 #define COMP_DELAYED 2
66 #define CURVE25519_SIZE 32
68 enum kex_init_proposals {
70 PROPOSAL_SERVER_HOST_KEY_ALGS,
71 PROPOSAL_ENC_ALGS_CTOS,
72 PROPOSAL_ENC_ALGS_STOC,
73 PROPOSAL_MAC_ALGS_CTOS,
74 PROPOSAL_MAC_ALGS_STOC,
75 PROPOSAL_COMP_ALGS_CTOS,
76 PROPOSAL_COMP_ALGS_STOC,
98 #define KEX_INIT_SENT 0x0001
102 const struct sshcipher *cipher;
125 size_t session_id_len;
126 struct newkeys *newkeys[MODE_MAX];
143 char *client_version_string;
144 char *server_version_string;
146 int (*verify_host_key)(struct sshkey *, struct ssh *);
147 struct sshkey *(*load_host_public_key)(int, int, struct ssh *);
148 struct sshkey *(*load_host_private_key)(int, int, struct ssh *);
149 int (*host_key_index)(struct sshkey *, int, struct ssh *);
150 int (*sign)(struct sshkey *, struct sshkey *, u_char **, size_t *,
151 const u_char *, size_t, const char *, u_int);
152 int (*kex[KEX_MAX])(struct ssh *);
153 /* kex specific state */
155 u_int min, max, nbits; /* GEX */
156 EC_KEY *ec_client_key; /* ECDH */
157 const EC_GROUP *ec_group; /* ECDH */
158 u_char c25519_client_key[CURVE25519_SIZE]; /* 25519 */
159 u_char c25519_client_pubkey[CURVE25519_SIZE]; /* 25519 */
162 int kex_names_valid(const char *);
163 char *kex_alg_list(char);
164 char *kex_names_cat(const char *, const char *);
165 int kex_assemble_names(const char *, char **);
167 int kex_new(struct ssh *, char *[PROPOSAL_MAX], struct kex **);
168 int kex_setup(struct ssh *, char *[PROPOSAL_MAX]);
169 void kex_free_newkeys(struct newkeys *);
170 void kex_free(struct kex *);
172 int kex_buf2prop(struct sshbuf *, int *, char ***);
173 int kex_prop2buf(struct sshbuf *, char *proposal[PROPOSAL_MAX]);
174 void kex_prop_free(char **);
176 int kex_send_kexinit(struct ssh *);
177 int kex_input_kexinit(int, u_int32_t, void *);
178 int kex_input_ext_info(int, u_int32_t, void *);
179 int kex_derive_keys(struct ssh *, u_char *, u_int, const struct sshbuf *);
180 int kex_derive_keys_bn(struct ssh *, u_char *, u_int, const BIGNUM *);
181 int kex_send_newkeys(struct ssh *);
182 int kex_start_rekex(struct ssh *);
184 int kexdh_client(struct ssh *);
185 int kexdh_server(struct ssh *);
186 int kexgex_client(struct ssh *);
187 int kexgex_server(struct ssh *);
188 int kexecdh_client(struct ssh *);
189 int kexecdh_server(struct ssh *);
190 int kexc25519_client(struct ssh *);
191 int kexc25519_server(struct ssh *);
193 int kex_dh_hash(const char *, const char *,
194 const u_char *, size_t, const u_char *, size_t, const u_char *, size_t,
195 const BIGNUM *, const BIGNUM *, const BIGNUM *, u_char *, size_t *);
197 int kexgex_hash(int, const char *, const char *,
198 const u_char *, size_t, const u_char *, size_t, const u_char *, size_t,
200 const BIGNUM *, const BIGNUM *, const BIGNUM *,
201 const BIGNUM *, const BIGNUM *,
204 int kex_ecdh_hash(int, const EC_GROUP *, const char *, const char *,
205 const u_char *, size_t, const u_char *, size_t, const u_char *, size_t,
206 const EC_POINT *, const EC_POINT *, const BIGNUM *, u_char *, size_t *);
208 int kex_c25519_hash(int, const char *, const char *, const char *, size_t,
209 const char *, size_t, const u_char *, size_t, const u_char *, const u_char *,
210 const u_char *, size_t, u_char *, size_t *);
212 void kexc25519_keygen(u_char key[CURVE25519_SIZE], u_char pub[CURVE25519_SIZE])
213 __attribute__((__bounded__(__minbytes__, 1, CURVE25519_SIZE)))
214 __attribute__((__bounded__(__minbytes__, 2, CURVE25519_SIZE)));
215 int kexc25519_shared_key(const u_char key[CURVE25519_SIZE],
216 const u_char pub[CURVE25519_SIZE], struct sshbuf *out)
217 __attribute__((__bounded__(__minbytes__, 1, CURVE25519_SIZE)))
218 __attribute__((__bounded__(__minbytes__, 2, CURVE25519_SIZE)));
221 derive_ssh1_session_id(BIGNUM *, BIGNUM *, u_int8_t[8], u_int8_t[16]);
223 #if defined(DEBUG_KEX) || defined(DEBUG_KEXDH) || defined(DEBUG_KEXECDH)
224 void dump_digest(char *, u_char *, int);
227 #if !defined(WITH_OPENSSL) || !defined(OPENSSL_HAS_ECC)