1 /* $OpenBSD: kex.h,v 1.81 2016/09/28 21:44:52 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_SHA1 "diffie-hellman-group14-sha1"
55 #define KEX_DH14_SHA256 "diffie-hellman-group14-sha256"
56 #define KEX_DH16_SHA512 "diffie-hellman-group16-sha512"
57 #define KEX_DH18_SHA512 "diffie-hellman-group18-sha512"
58 #define KEX_DHGEX_SHA1 "diffie-hellman-group-exchange-sha1"
59 #define KEX_DHGEX_SHA256 "diffie-hellman-group-exchange-sha256"
60 #define KEX_ECDH_SHA2_NISTP256 "ecdh-sha2-nistp256"
61 #define KEX_ECDH_SHA2_NISTP384 "ecdh-sha2-nistp384"
62 #define KEX_ECDH_SHA2_NISTP521 "ecdh-sha2-nistp521"
63 #define KEX_CURVE25519_SHA256 "curve25519-sha256"
64 #define KEX_CURVE25519_SHA256_OLD "curve25519-sha256@libssh.org"
68 #define COMP_DELAYED 2
70 #define CURVE25519_SIZE 32
72 enum kex_init_proposals {
74 PROPOSAL_SERVER_HOST_KEY_ALGS,
75 PROPOSAL_ENC_ALGS_CTOS,
76 PROPOSAL_ENC_ALGS_STOC,
77 PROPOSAL_MAC_ALGS_CTOS,
78 PROPOSAL_MAC_ALGS_STOC,
79 PROPOSAL_COMP_ALGS_CTOS,
80 PROPOSAL_COMP_ALGS_STOC,
105 #define KEX_INIT_SENT 0x0001
109 const struct sshcipher *cipher;
132 size_t session_id_len;
133 struct newkeys *newkeys[MODE_MAX];
150 char *client_version_string;
151 char *server_version_string;
153 int (*verify_host_key)(struct sshkey *, struct ssh *);
154 struct sshkey *(*load_host_public_key)(int, int, struct ssh *);
155 struct sshkey *(*load_host_private_key)(int, int, struct ssh *);
156 int (*host_key_index)(struct sshkey *, int, struct ssh *);
157 int (*sign)(struct sshkey *, struct sshkey *, u_char **, size_t *,
158 const u_char *, size_t, const char *, u_int);
159 int (*kex[KEX_MAX])(struct ssh *);
160 /* kex specific state */
162 u_int min, max, nbits; /* GEX */
163 EC_KEY *ec_client_key; /* ECDH */
164 const EC_GROUP *ec_group; /* ECDH */
165 u_char c25519_client_key[CURVE25519_SIZE]; /* 25519 */
166 u_char c25519_client_pubkey[CURVE25519_SIZE]; /* 25519 */
169 int kex_names_valid(const char *);
170 char *kex_alg_list(char);
171 char *kex_names_cat(const char *, const char *);
172 int kex_assemble_names(const char *, char **);
174 int kex_new(struct ssh *, char *[PROPOSAL_MAX], struct kex **);
175 int kex_setup(struct ssh *, char *[PROPOSAL_MAX]);
176 void kex_free_newkeys(struct newkeys *);
177 void kex_free(struct kex *);
179 int kex_buf2prop(struct sshbuf *, int *, char ***);
180 int kex_prop2buf(struct sshbuf *, char *proposal[PROPOSAL_MAX]);
181 void kex_prop_free(char **);
183 int kex_send_kexinit(struct ssh *);
184 int kex_input_kexinit(int, u_int32_t, void *);
185 int kex_input_ext_info(int, u_int32_t, void *);
186 int kex_derive_keys(struct ssh *, u_char *, u_int, const struct sshbuf *);
187 int kex_derive_keys_bn(struct ssh *, u_char *, u_int, const BIGNUM *);
188 int kex_send_newkeys(struct ssh *);
189 int kex_start_rekex(struct ssh *);
191 int kexdh_client(struct ssh *);
192 int kexdh_server(struct ssh *);
193 int kexgex_client(struct ssh *);
194 int kexgex_server(struct ssh *);
195 int kexecdh_client(struct ssh *);
196 int kexecdh_server(struct ssh *);
197 int kexc25519_client(struct ssh *);
198 int kexc25519_server(struct ssh *);
200 int kex_dh_hash(int, const char *, const char *,
201 const u_char *, size_t, const u_char *, size_t, const u_char *, size_t,
202 const BIGNUM *, const BIGNUM *, const BIGNUM *, u_char *, size_t *);
204 int kexgex_hash(int, const char *, const char *,
205 const u_char *, size_t, const u_char *, size_t, const u_char *, size_t,
207 const BIGNUM *, const BIGNUM *, const BIGNUM *,
208 const BIGNUM *, const BIGNUM *,
211 int kex_ecdh_hash(int, const EC_GROUP *, const char *, const char *,
212 const u_char *, size_t, const u_char *, size_t, const u_char *, size_t,
213 const EC_POINT *, const EC_POINT *, const BIGNUM *, u_char *, size_t *);
215 int kex_c25519_hash(int, const char *, const char *,
216 const u_char *, size_t, const u_char *, size_t,
217 const u_char *, size_t, const u_char *, const u_char *,
218 const u_char *, size_t, u_char *, size_t *);
220 void kexc25519_keygen(u_char key[CURVE25519_SIZE], u_char pub[CURVE25519_SIZE])
221 __attribute__((__bounded__(__minbytes__, 1, CURVE25519_SIZE)))
222 __attribute__((__bounded__(__minbytes__, 2, CURVE25519_SIZE)));
223 int kexc25519_shared_key(const u_char key[CURVE25519_SIZE],
224 const u_char pub[CURVE25519_SIZE], struct sshbuf *out)
225 __attribute__((__bounded__(__minbytes__, 1, CURVE25519_SIZE)))
226 __attribute__((__bounded__(__minbytes__, 2, CURVE25519_SIZE)));
229 derive_ssh1_session_id(BIGNUM *, BIGNUM *, u_int8_t[8], u_int8_t[16]);
231 #if defined(DEBUG_KEX) || defined(DEBUG_KEXDH) || defined(DEBUG_KEXECDH)
232 void dump_digest(char *, u_char *, int);
235 #if !defined(WITH_OPENSSL) || !defined(OPENSSL_HAS_ECC)