1 /* $OpenBSD: kex.h,v 1.64 2014/05/02 03:27:54 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 <signal.h> 30 #include <openssl/evp.h> 31 #include <openssl/hmac.h> 32 #ifdef OPENSSL_HAS_ECC 33 #include <openssl/ec.h> 34 #endif 35 36 #define KEX_COOKIE_LEN 16 37 38 #define KEX_DH1 "diffie-hellman-group1-sha1" 39 #define KEX_DH14 "diffie-hellman-group14-sha1" 40 #define KEX_DHGEX_SHA1 "diffie-hellman-group-exchange-sha1" 41 #define KEX_DHGEX_SHA256 "diffie-hellman-group-exchange-sha256" 42 #define KEX_RESUME "resume@appgate.com" 43 #define KEX_ECDH_SHA2_NISTP256 "ecdh-sha2-nistp256" 44 #define KEX_ECDH_SHA2_NISTP384 "ecdh-sha2-nistp384" 45 #define KEX_ECDH_SHA2_NISTP521 "ecdh-sha2-nistp521" 46 #define KEX_CURVE25519_SHA256 "curve25519-sha256@libssh.org" 47 48 #define COMP_NONE 0 49 #define COMP_ZLIB 1 50 #define COMP_DELAYED 2 51 52 enum kex_init_proposals { 53 PROPOSAL_KEX_ALGS, 54 PROPOSAL_SERVER_HOST_KEY_ALGS, 55 PROPOSAL_ENC_ALGS_CTOS, 56 PROPOSAL_ENC_ALGS_STOC, 57 PROPOSAL_MAC_ALGS_CTOS, 58 PROPOSAL_MAC_ALGS_STOC, 59 PROPOSAL_COMP_ALGS_CTOS, 60 PROPOSAL_COMP_ALGS_STOC, 61 PROPOSAL_LANG_CTOS, 62 PROPOSAL_LANG_STOC, 63 PROPOSAL_MAX 64 }; 65 66 enum kex_modes { 67 MODE_IN, 68 MODE_OUT, 69 MODE_MAX 70 }; 71 72 enum kex_exchange { 73 KEX_DH_GRP1_SHA1, 74 KEX_DH_GRP14_SHA1, 75 KEX_DH_GEX_SHA1, 76 KEX_DH_GEX_SHA256, 77 KEX_ECDH_SHA2, 78 KEX_C25519_SHA256, 79 KEX_MAX 80 }; 81 82 #define KEX_INIT_SENT 0x0001 83 84 typedef struct Kex Kex; 85 typedef struct Mac Mac; 86 typedef struct Comp Comp; 87 typedef struct Enc Enc; 88 typedef struct Newkeys Newkeys; 89 90 struct Enc { 91 char *name; 92 const Cipher *cipher; 93 int enabled; 94 u_int key_len; 95 u_int iv_len; 96 u_int block_size; 97 u_char *key; 98 u_char *iv; 99 }; 100 struct Mac { 101 char *name; 102 int enabled; 103 u_int mac_len; 104 u_char *key; 105 u_int key_len; 106 int type; 107 int etm; /* Encrypt-then-MAC */ 108 struct ssh_hmac_ctx *hmac_ctx; 109 struct umac_ctx *umac_ctx; 110 }; 111 struct Comp { 112 int type; 113 int enabled; 114 char *name; 115 }; 116 struct Newkeys { 117 Enc enc; 118 Mac mac; 119 Comp comp; 120 }; 121 struct Kex { 122 u_char *session_id; 123 u_int session_id_len; 124 Newkeys *newkeys[MODE_MAX]; 125 u_int we_need; 126 u_int dh_need; 127 int server; 128 char *name; 129 int hostkey_type; 130 int kex_type; 131 int roaming; 132 Buffer my; 133 Buffer peer; 134 sig_atomic_t done; 135 int flags; 136 int hash_alg; 137 int ec_nid; 138 char *client_version_string; 139 char *server_version_string; 140 int (*verify_host_key)(Key *); 141 Key *(*load_host_public_key)(int); 142 Key *(*load_host_private_key)(int); 143 int (*host_key_index)(Key *); 144 void (*sign)(Key *, Key *, u_char **, u_int *, u_char *, u_int); 145 void (*kex[KEX_MAX])(Kex *); 146 }; 147 148 int kex_names_valid(const char *); 149 char *kex_alg_list(char); 150 151 void kex_prop2buf(Buffer *, char *proposal[PROPOSAL_MAX]); 152 153 Kex *kex_setup(char *[PROPOSAL_MAX]); 154 void kex_finish(Kex *); 155 156 void kex_send_kexinit(Kex *); 157 void kex_input_kexinit(int, u_int32_t, void *); 158 void kex_derive_keys(Kex *, u_char *, u_int, const u_char *, u_int); 159 void kex_derive_keys_bn(Kex *, u_char *, u_int, const BIGNUM *); 160 161 Newkeys *kex_get_newkeys(int); 162 163 void kexdh_client(Kex *); 164 void kexdh_server(Kex *); 165 void kexgex_client(Kex *); 166 void kexgex_server(Kex *); 167 void kexecdh_client(Kex *); 168 void kexecdh_server(Kex *); 169 void kexc25519_client(Kex *); 170 void kexc25519_server(Kex *); 171 172 void 173 kex_dh_hash(char *, char *, char *, int, char *, int, u_char *, int, 174 BIGNUM *, BIGNUM *, BIGNUM *, u_char **, u_int *); 175 void 176 kexgex_hash(int, char *, char *, char *, int, char *, 177 int, u_char *, int, int, int, int, BIGNUM *, BIGNUM *, BIGNUM *, 178 BIGNUM *, BIGNUM *, u_char **, u_int *); 179 #ifdef OPENSSL_HAS_ECC 180 void 181 kex_ecdh_hash(int, const EC_GROUP *, char *, char *, char *, int, 182 char *, int, u_char *, int, const EC_POINT *, const EC_POINT *, 183 const BIGNUM *, u_char **, u_int *); 184 #endif 185 void 186 kex_c25519_hash(int, char *, char *, char *, int, 187 char *, int, u_char *, int, const u_char *, const u_char *, 188 const u_char *, u_int, u_char **, u_int *); 189 190 #define CURVE25519_SIZE 32 191 void kexc25519_keygen(u_char[CURVE25519_SIZE], u_char[CURVE25519_SIZE]) 192 __attribute__((__bounded__(__minbytes__, 1, CURVE25519_SIZE))) 193 __attribute__((__bounded__(__minbytes__, 2, CURVE25519_SIZE))); 194 void kexc25519_shared_key(const u_char key[CURVE25519_SIZE], 195 const u_char pub[CURVE25519_SIZE], Buffer *out) 196 __attribute__((__bounded__(__minbytes__, 1, CURVE25519_SIZE))) 197 __attribute__((__bounded__(__minbytes__, 2, CURVE25519_SIZE))); 198 199 void 200 derive_ssh1_session_id(BIGNUM *, BIGNUM *, u_int8_t[8], u_int8_t[16]); 201 202 #if defined(DEBUG_KEX) || defined(DEBUG_KEXDH) || defined(DEBUG_KEXECDH) 203 void dump_digest(char *, u_char *, int); 204 #endif 205 206 #endif 207