1 /* $NetBSD: kex.h,v 1.8 2014/10/19 16:30:58 christos Exp $ */ 2 /* $OpenBSD: kex.h,v 1.64 2014/05/02 03:27:54 djm Exp $ */ 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 <openssl/evp.h> 31 #include <openssl/hmac.h> 32 #include <openssl/ec.h> 33 34 #define KEX_COOKIE_LEN 16 35 36 #define KEX_DH1 "diffie-hellman-group1-sha1" 37 #define KEX_DH14 "diffie-hellman-group14-sha1" 38 #define KEX_DHGEX_SHA1 "diffie-hellman-group-exchange-sha1" 39 #define KEX_DHGEX_SHA256 "diffie-hellman-group-exchange-sha256" 40 #define KEX_RESUME "resume@appgate.com" 41 #define KEX_ECDH_SHA2_NISTP256 "ecdh-sha2-nistp256" 42 #define KEX_ECDH_SHA2_NISTP384 "ecdh-sha2-nistp384" 43 #define KEX_ECDH_SHA2_NISTP521 "ecdh-sha2-nistp521" 44 #define KEX_CURVE25519_SHA256 "curve25519-sha256@libssh.org" 45 46 #define COMP_NONE 0 47 #define COMP_ZLIB 1 48 #define COMP_DELAYED 2 49 50 enum kex_init_proposals { 51 PROPOSAL_KEX_ALGS, 52 PROPOSAL_SERVER_HOST_KEY_ALGS, 53 PROPOSAL_ENC_ALGS_CTOS, 54 PROPOSAL_ENC_ALGS_STOC, 55 PROPOSAL_MAC_ALGS_CTOS, 56 PROPOSAL_MAC_ALGS_STOC, 57 PROPOSAL_COMP_ALGS_CTOS, 58 PROPOSAL_COMP_ALGS_STOC, 59 PROPOSAL_LANG_CTOS, 60 PROPOSAL_LANG_STOC, 61 PROPOSAL_MAX 62 }; 63 64 enum kex_modes { 65 MODE_IN, 66 MODE_OUT, 67 MODE_MAX 68 }; 69 70 enum kex_exchange { 71 KEX_DH_GRP1_SHA1, 72 KEX_DH_GRP14_SHA1, 73 KEX_DH_GEX_SHA1, 74 KEX_DH_GEX_SHA256, 75 KEX_ECDH_SHA2, 76 KEX_C25519_SHA256, 77 KEX_MAX 78 }; 79 80 #define KEX_INIT_SENT 0x0001 81 82 typedef struct Kex Kex; 83 typedef struct Mac Mac; 84 typedef struct Comp Comp; 85 typedef struct Enc Enc; 86 typedef struct Newkeys Newkeys; 87 88 struct Enc { 89 char *name; 90 const Cipher *cipher; 91 int enabled; 92 u_int key_len; 93 u_int iv_len; 94 u_int block_size; 95 u_char *key; 96 u_char *iv; 97 }; 98 struct Mac { 99 char *name; 100 int enabled; 101 u_int mac_len; 102 u_char *key; 103 u_int key_len; 104 int type; 105 int etm; /* Encrypt-then-MAC */ 106 struct ssh_hmac_ctx *hmac_ctx; 107 struct umac_ctx *umac_ctx; 108 }; 109 struct Comp { 110 int type; 111 int enabled; 112 char *name; 113 }; 114 struct Newkeys { 115 Enc enc; 116 Mac mac; 117 Comp comp; 118 }; 119 struct Kex { 120 u_char *session_id; 121 u_int session_id_len; 122 Newkeys *newkeys[MODE_MAX]; 123 u_int we_need; 124 u_int dh_need; 125 int server; 126 char *name; 127 int hostkey_type; 128 int kex_type; 129 int roaming; 130 Buffer my; 131 Buffer peer; 132 sig_atomic_t done; 133 int flags; 134 int hash_alg; 135 int ec_nid; 136 char *client_version_string; 137 char *server_version_string; 138 int (*verify_host_key)(Key *); 139 Key *(*load_host_public_key)(int); 140 Key *(*load_host_private_key)(int); 141 int (*host_key_index)(Key *); 142 void (*sign)(Key *, Key *, u_char **, u_int *, u_char *, u_int); 143 void (*kex[KEX_MAX])(Kex *); 144 }; 145 146 void kex_prop2buf(Buffer *, const char *proposal[PROPOSAL_MAX]); 147 148 int kex_names_valid(const char *); 149 char *kex_alg_list(char); 150 151 Kex *kex_setup(const char *[PROPOSAL_MAX]); 152 void kex_finish(Kex *); 153 154 void kex_send_kexinit(Kex *); 155 void kex_input_kexinit(int, u_int32_t, void *); 156 void kex_derive_keys(Kex *, u_char *, u_int, const u_char *, u_int); 157 void kex_derive_keys_bn(Kex *, u_char *, u_int, const BIGNUM *); 158 159 Newkeys *kex_get_newkeys(int); 160 161 void kexdh_client(Kex *); 162 void kexdh_server(Kex *); 163 void kexgex_client(Kex *); 164 void kexgex_server(Kex *); 165 void kexecdh_client(Kex *); 166 void kexecdh_server(Kex *); 167 void kexc25519_client(Kex *); 168 void kexc25519_server(Kex *); 169 170 void 171 kex_dh_hash(char *, char *, char *, int, char *, int, u_char *, int, 172 BIGNUM *, BIGNUM *, BIGNUM *, u_char **, u_int *); 173 void 174 kexgex_hash(int, char *, char *, char *, int, char *, 175 int, u_char *, int, int, int, int, BIGNUM *, BIGNUM *, BIGNUM *, 176 BIGNUM *, BIGNUM *, u_char **, u_int *); 177 void 178 kex_ecdh_hash(int, const EC_GROUP *, char *, char *, char *, int, 179 char *, int, u_char *, int, const EC_POINT *, const EC_POINT *, 180 const BIGNUM *, u_char **, u_int *); 181 void 182 kex_c25519_hash(int, char *, char *, char *, int, 183 char *, int, u_char *, int, const u_char *, const u_char *, 184 const u_char *, u_int, u_char **, u_int *); 185 186 #define CURVE25519_SIZE 32 187 void kexc25519_keygen(u_char[CURVE25519_SIZE], u_char[CURVE25519_SIZE]) 188 __attribute__((__bounded__(__minbytes__, 1, CURVE25519_SIZE))) 189 __attribute__((__bounded__(__minbytes__, 2, CURVE25519_SIZE))); 190 void kexc25519_shared_key(const u_char key[CURVE25519_SIZE], 191 const u_char pub[CURVE25519_SIZE], Buffer *out) 192 __attribute__((__bounded__(__minbytes__, 1, CURVE25519_SIZE))) 193 __attribute__((__bounded__(__minbytes__, 2, CURVE25519_SIZE))); 194 195 void 196 derive_ssh1_session_id(BIGNUM *, BIGNUM *, u_int8_t[8], u_int8_t[16]); 197 198 #if defined(DEBUG_KEX) || defined(DEBUG_KEXDH) || defined(DEBUG_KEXECDH) 199 void dump_digest(char *, u_char *, int); 200 #endif 201 202 #endif 203