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