Globus Toolkit  6.0.1493297102
kex.h
1 /* $OpenBSD: kex.h,v 1.78 2016/05/02 10:26:04 djm Exp $ */
2 
3 /*
4  * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
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.
14  *
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.
25  */
26 #ifndef KEX_H
27 #define KEX_H
28 
29 #include "mac.h"
30 #include "buffer.h" /* XXX for typedef */
31 #include "key.h" /* XXX for typedef */
32 
33 #ifdef WITH_LEAKMALLOC
34 #include "leakmalloc.h"
35 #endif
36 
37 #ifdef WITH_OPENSSL
38 # ifdef OPENSSL_HAS_ECC
39 # include <openssl/ec.h>
40 # else /* OPENSSL_HAS_ECC */
41 # define EC_KEY void
42 # define EC_GROUP void
43 # define EC_POINT void
44 # endif /* OPENSSL_HAS_ECC */
45 #else /* WITH_OPENSSL */
46 # define EC_KEY void
47 # define EC_GROUP void
48 # define EC_POINT void
49 #endif /* WITH_OPENSSL */
50 
51 #define KEX_COOKIE_LEN 16
52 
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@libssh.org"
64 
65 #define COMP_NONE 0
66 #define COMP_ZLIB 1
67 #define COMP_DELAYED 2
68 
69 #define CURVE25519_SIZE 32
70 
71 enum kex_init_proposals {
72  PROPOSAL_KEX_ALGS,
73  PROPOSAL_SERVER_HOST_KEY_ALGS,
74  PROPOSAL_ENC_ALGS_CTOS,
75  PROPOSAL_ENC_ALGS_STOC,
76  PROPOSAL_MAC_ALGS_CTOS,
77  PROPOSAL_MAC_ALGS_STOC,
78  PROPOSAL_COMP_ALGS_CTOS,
79  PROPOSAL_COMP_ALGS_STOC,
80  PROPOSAL_LANG_CTOS,
81  PROPOSAL_LANG_STOC,
82  PROPOSAL_MAX
83 };
84 
85 enum kex_modes {
86  MODE_IN,
87  MODE_OUT,
88  MODE_MAX
89 };
90 
91 enum kex_exchange {
92  KEX_DH_GRP1_SHA1,
93  KEX_DH_GRP14_SHA1,
94  KEX_DH_GRP14_SHA256,
95  KEX_DH_GRP16_SHA512,
96  KEX_DH_GRP18_SHA512,
97  KEX_DH_GEX_SHA1,
98  KEX_DH_GEX_SHA256,
99  KEX_ECDH_SHA2,
100  KEX_GSS_GRP1_SHA1,
101  KEX_GSS_GRP14_SHA1,
102  KEX_GSS_GRP14_SHA256,
103  KEX_GSS_GRP16_SHA512,
104  KEX_GSS_GRP18_SHA512,
105  KEX_GSS_GEX_SHA1,
106  KEX_C25519_SHA256,
107  KEX_MAX
108 };
109 
110 #define KEX_INIT_SENT 0x0001
111 
112 struct sshenc {
113  char *name;
114  const struct sshcipher *cipher;
115  int enabled;
116  u_int key_len;
117  u_int iv_len;
118  u_int block_size;
119  u_char *key;
120  u_char *iv;
121 };
122 struct sshcomp {
123  u_int type;
124  int enabled;
125  char *name;
126 };
127 struct newkeys {
128  struct sshenc enc;
129  struct sshmac mac;
130  struct sshcomp comp;
131 };
132 
133 struct ssh;
134 
135 struct kex {
136  u_char *session_id;
137  size_t session_id_len;
138  struct newkeys *newkeys[MODE_MAX];
139  u_int we_need;
140  u_int dh_need;
141  int server;
142  char *name;
143  char *hostkey_alg;
144  int hostkey_type;
145  int hostkey_nid;
146  u_int kex_type;
147  int rsa_sha2;
148  int ext_info_c;
149  struct sshbuf *my;
150  struct sshbuf *peer;
151  sig_atomic_t done;
152  u_int flags;
153 #ifdef GSSAPI
154  int gss_deleg_creds;
155  int gss_trust_dns;
156  char *gss_host;
157  char *gss_client;
158 #endif
159  int hash_alg;
160  int ec_nid;
161  char *client_version_string;
162  char *server_version_string;
163  char *failed_choice;
164  int (*verify_host_key)(struct sshkey *, struct ssh *);
165  struct sshkey *(*load_host_public_key)(int, int, struct ssh *);
166  struct sshkey *(*load_host_private_key)(int, int, struct ssh *);
167  int (*host_key_index)(struct sshkey *, int, struct ssh *);
168  int (*sign)(struct sshkey *, struct sshkey *, u_char **, size_t *,
169  const u_char *, size_t, const char *, u_int);
170  int (*kex[KEX_MAX])(struct ssh *);
171  /* kex specific state */
172  DH *dh; /* DH */
173  u_int min, max, nbits; /* GEX */
174  EC_KEY *ec_client_key; /* ECDH */
175  const EC_GROUP *ec_group; /* ECDH */
176  u_char c25519_client_key[CURVE25519_SIZE]; /* 25519 */
177  u_char c25519_client_pubkey[CURVE25519_SIZE]; /* 25519 */
178 };
179 
180 int kex_names_valid(const char *);
181 char *kex_alg_list(char);
182 char *kex_names_cat(const char *, const char *);
183 int kex_assemble_names(const char *, char **);
184 
185 int kex_new(struct ssh *, char *[PROPOSAL_MAX], struct kex **);
186 int kex_setup(struct ssh *, char *[PROPOSAL_MAX]);
187 void kex_free_newkeys(struct newkeys *);
188 void kex_free(struct kex *);
189 
190 int kex_buf2prop(struct sshbuf *, int *, char ***);
191 int kex_prop2buf(struct sshbuf *, char *proposal[PROPOSAL_MAX]);
192 void kex_prop_free(char **);
193 
194 int kex_send_kexinit(struct ssh *);
195 int kex_input_kexinit(int, u_int32_t, void *);
196 int kex_input_ext_info(int, u_int32_t, void *);
197 int kex_derive_keys(struct ssh *, u_char *, u_int, const struct sshbuf *);
198 int kex_derive_keys_bn(struct ssh *, u_char *, u_int, const BIGNUM *);
199 int kex_send_newkeys(struct ssh *);
200 int kex_start_rekex(struct ssh *);
201 
202 int kexdh_client(struct ssh *);
203 int kexdh_server(struct ssh *);
204 int kexgex_client(struct ssh *);
205 int kexgex_server(struct ssh *);
206 int kexecdh_client(struct ssh *);
207 int kexecdh_server(struct ssh *);
208 int kexc25519_client(struct ssh *);
209 int kexc25519_server(struct ssh *);
210 
211 #ifdef GSSAPI
212 int kexgss_client(struct ssh *);
213 int kexgss_server(struct ssh *);
214 #endif
215 
216 int kex_dh_hash(int, const char *, const char *,
217  const u_char *, size_t, const u_char *, size_t, const u_char *, size_t,
218  const BIGNUM *, const BIGNUM *, const BIGNUM *, u_char *, size_t *);
219 
220 int kexgex_hash(int, const char *, const char *,
221  const u_char *, size_t, const u_char *, size_t, const u_char *, size_t,
222  int, int, int,
223  const BIGNUM *, const BIGNUM *, const BIGNUM *,
224  const BIGNUM *, const BIGNUM *,
225  u_char *, size_t *);
226 
227 int kex_ecdh_hash(int, const EC_GROUP *, const char *, const char *,
228  const u_char *, size_t, const u_char *, size_t, const u_char *, size_t,
229  const EC_POINT *, const EC_POINT *, const BIGNUM *, u_char *, size_t *);
230 
231 int kex_c25519_hash(int, const char *, const char *,
232  const u_char *, size_t, const u_char *, size_t,
233  const u_char *, size_t, const u_char *, const u_char *,
234  const u_char *, size_t, u_char *, size_t *);
235 
236 void kexc25519_keygen(u_char key[CURVE25519_SIZE], u_char pub[CURVE25519_SIZE])
237  __attribute__((__bounded__(__minbytes__, 1, CURVE25519_SIZE)))
238  __attribute__((__bounded__(__minbytes__, 2, CURVE25519_SIZE)));
239 int kexc25519_shared_key(const u_char key[CURVE25519_SIZE],
240  const u_char pub[CURVE25519_SIZE], struct sshbuf *out)
241  __attribute__((__bounded__(__minbytes__, 1, CURVE25519_SIZE)))
242  __attribute__((__bounded__(__minbytes__, 2, CURVE25519_SIZE)));
243 
244 int
245 derive_ssh1_session_id(BIGNUM *, BIGNUM *, u_int8_t[8], u_int8_t[16]);
246 
247 #if defined(DEBUG_KEX) || defined(DEBUG_KEXDH) || defined(DEBUG_KEXECDH)
248 void dump_digest(char *, u_char *, int);
249 #endif
250 
251 #if !defined(WITH_OPENSSL) || !defined(OPENSSL_HAS_ECC)
252 # undef EC_KEY
253 # undef EC_GROUP
254 # undef EC_POINT
255 #endif
256 
257 #endif