1 /* $OpenBSD: kex.h,v 1.62 2014/01/27 18:58:14 markus Exp $ */ 2 /* $FreeBSD$ */ 3 4 /* 5 * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 #ifndef KEX_H 28 #define KEX_H 29 30 #include <signal.h> 31 #include <openssl/evp.h> 32 #include <openssl/hmac.h> 33 #ifdef OPENSSL_HAS_ECC 34 #include <openssl/ec.h> 35 #endif 36 37 #define KEX_COOKIE_LEN 16 38 39 #define KEX_DH1 "diffie-hellman-group1-sha1" 40 #define KEX_DH14 "diffie-hellman-group14-sha1" 41 #define KEX_DHGEX_SHA1 "diffie-hellman-group-exchange-sha1" 42 #define KEX_DHGEX_SHA256 "diffie-hellman-group-exchange-sha256" 43 #define KEX_RESUME "resume@appgate.com" 44 #define KEX_ECDH_SHA2_NISTP256 "ecdh-sha2-nistp256" 45 #define KEX_ECDH_SHA2_NISTP384 "ecdh-sha2-nistp384" 46 #define KEX_ECDH_SHA2_NISTP521 "ecdh-sha2-nistp521" 47 #define KEX_CURVE25519_SHA256 "curve25519-sha256@libssh.org" 48 49 #define COMP_NONE 0 50 #define COMP_ZLIB 1 51 #define COMP_DELAYED 2 52 53 enum kex_init_proposals { 54 PROPOSAL_KEX_ALGS, 55 PROPOSAL_SERVER_HOST_KEY_ALGS, 56 PROPOSAL_ENC_ALGS_CTOS, 57 PROPOSAL_ENC_ALGS_STOC, 58 PROPOSAL_MAC_ALGS_CTOS, 59 PROPOSAL_MAC_ALGS_STOC, 60 PROPOSAL_COMP_ALGS_CTOS, 61 PROPOSAL_COMP_ALGS_STOC, 62 PROPOSAL_LANG_CTOS, 63 PROPOSAL_LANG_STOC, 64 PROPOSAL_MAX 65 }; 66 67 enum kex_modes { 68 MODE_IN, 69 MODE_OUT, 70 MODE_MAX 71 }; 72 73 enum kex_exchange { 74 KEX_DH_GRP1_SHA1, 75 KEX_DH_GRP14_SHA1, 76 KEX_DH_GEX_SHA1, 77 KEX_DH_GEX_SHA256, 78 KEX_ECDH_SHA2, 79 KEX_C25519_SHA256, 80 KEX_MAX 81 }; 82 83 #define KEX_INIT_SENT 0x0001 84 85 typedef struct Kex Kex; 86 typedef struct Mac Mac; 87 typedef struct Comp Comp; 88 typedef struct Enc Enc; 89 typedef struct Newkeys Newkeys; 90 91 struct Enc { 92 char *name; 93 const Cipher *cipher; 94 int enabled; 95 u_int key_len; 96 u_int iv_len; 97 u_int block_size; 98 u_char *key; 99 u_char *iv; 100 }; 101 struct Mac { 102 char *name; 103 int enabled; 104 u_int mac_len; 105 u_char *key; 106 u_int key_len; 107 int type; 108 int etm; /* Encrypt-then-MAC */ 109 struct ssh_hmac_ctx *hmac_ctx; 110 struct umac_ctx *umac_ctx; 111 }; 112 struct Comp { 113 int type; 114 int enabled; 115 char *name; 116 }; 117 struct Newkeys { 118 Enc enc; 119 Mac mac; 120 Comp comp; 121 }; 122 struct Kex { 123 u_char *session_id; 124 u_int session_id_len; 125 Newkeys *newkeys[MODE_MAX]; 126 u_int we_need; 127 u_int dh_need; 128 int server; 129 char *name; 130 int hostkey_type; 131 int kex_type; 132 int roaming; 133 Buffer my; 134 Buffer peer; 135 sig_atomic_t done; 136 int flags; 137 int hash_alg; 138 int ec_nid; 139 char *client_version_string; 140 char *server_version_string; 141 int (*verify_host_key)(Key *); 142 Key *(*load_host_public_key)(int); 143 Key *(*load_host_private_key)(int); 144 int (*host_key_index)(Key *); 145 void (*sign)(Key *, Key *, u_char **, u_int *, u_char *, u_int); 146 void (*kex[KEX_MAX])(Kex *); 147 }; 148 149 int kex_names_valid(const char *); 150 char *kex_alg_list(char); 151 152 #ifdef NONE_CIPHER_ENABLED 153 void kex_prop2buf(Buffer *, char *[PROPOSAL_MAX]); 154 #endif 155 156 Kex *kex_setup(char *[PROPOSAL_MAX]); 157 void kex_finish(Kex *); 158 159 void kex_send_kexinit(Kex *); 160 void kex_input_kexinit(int, u_int32_t, void *); 161 void kex_derive_keys(Kex *, u_char *, u_int, const u_char *, u_int); 162 void kex_derive_keys_bn(Kex *, u_char *, u_int, const BIGNUM *); 163 164 Newkeys *kex_get_newkeys(int); 165 166 void kexdh_client(Kex *); 167 void kexdh_server(Kex *); 168 void kexgex_client(Kex *); 169 void kexgex_server(Kex *); 170 void kexecdh_client(Kex *); 171 void kexecdh_server(Kex *); 172 void kexc25519_client(Kex *); 173 void kexc25519_server(Kex *); 174 175 void 176 kex_dh_hash(char *, char *, char *, int, char *, int, u_char *, int, 177 BIGNUM *, BIGNUM *, BIGNUM *, u_char **, u_int *); 178 void 179 kexgex_hash(int, char *, char *, char *, int, char *, 180 int, u_char *, int, int, int, int, BIGNUM *, BIGNUM *, BIGNUM *, 181 BIGNUM *, BIGNUM *, u_char **, u_int *); 182 #ifdef OPENSSL_HAS_ECC 183 void 184 kex_ecdh_hash(int, const EC_GROUP *, char *, char *, char *, int, 185 char *, int, u_char *, int, const EC_POINT *, const EC_POINT *, 186 const BIGNUM *, u_char **, u_int *); 187 #endif 188 void 189 kex_c25519_hash(int, char *, char *, char *, int, 190 char *, int, u_char *, int, const u_char *, const u_char *, 191 const u_char *, u_int, u_char **, u_int *); 192 193 #define CURVE25519_SIZE 32 194 void kexc25519_keygen(u_char[CURVE25519_SIZE], u_char[CURVE25519_SIZE]) 195 __attribute__((__bounded__(__minbytes__, 1, CURVE25519_SIZE))) 196 __attribute__((__bounded__(__minbytes__, 2, CURVE25519_SIZE))); 197 void kexc25519_shared_key(const u_char key[CURVE25519_SIZE], 198 const u_char pub[CURVE25519_SIZE], Buffer *out) 199 __attribute__((__bounded__(__minbytes__, 1, CURVE25519_SIZE))) 200 __attribute__((__bounded__(__minbytes__, 2, CURVE25519_SIZE))); 201 202 void 203 derive_ssh1_session_id(BIGNUM *, BIGNUM *, u_int8_t[8], u_int8_t[16]); 204 205 #if defined(DEBUG_KEX) || defined(DEBUG_KEXDH) || defined(DEBUG_KEXECDH) 206 void dump_digest(char *, u_char *, int); 207 #endif 208 209 #endif 210