1 /* $OpenBSD: kex.h,v 1.61 2014/01/25 10:12:50 dtucker 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 const EVP_MD *evp_md; 110 HMAC_CTX evp_ctx; 111 struct umac_ctx *umac_ctx; 112 }; 113 struct Comp { 114 int type; 115 int enabled; 116 char *name; 117 }; 118 struct Newkeys { 119 Enc enc; 120 Mac mac; 121 Comp comp; 122 }; 123 struct Kex { 124 u_char *session_id; 125 u_int session_id_len; 126 Newkeys *newkeys[MODE_MAX]; 127 u_int we_need; 128 u_int dh_need; 129 int server; 130 char *name; 131 int hostkey_type; 132 int kex_type; 133 int roaming; 134 Buffer my; 135 Buffer peer; 136 sig_atomic_t done; 137 int flags; 138 int hash_alg; 139 int ec_nid; 140 char *client_version_string; 141 char *server_version_string; 142 int (*verify_host_key)(Key *); 143 Key *(*load_host_public_key)(int); 144 Key *(*load_host_private_key)(int); 145 int (*host_key_index)(Key *); 146 void (*sign)(Key *, Key *, u_char **, u_int *, u_char *, u_int); 147 void (*kex[KEX_MAX])(Kex *); 148 }; 149 150 int kex_names_valid(const char *); 151 char *kex_alg_list(char); 152 153 #ifdef NONE_CIPHER_ENABLED 154 void kex_prop2buf(Buffer *, char *[PROPOSAL_MAX]); 155 #endif 156 157 Kex *kex_setup(char *[PROPOSAL_MAX]); 158 void kex_finish(Kex *); 159 160 void kex_send_kexinit(Kex *); 161 void kex_input_kexinit(int, u_int32_t, void *); 162 void kex_derive_keys(Kex *, u_char *, u_int, const u_char *, u_int); 163 void kex_derive_keys_bn(Kex *, u_char *, u_int, const BIGNUM *); 164 165 Newkeys *kex_get_newkeys(int); 166 167 void kexdh_client(Kex *); 168 void kexdh_server(Kex *); 169 void kexgex_client(Kex *); 170 void kexgex_server(Kex *); 171 void kexecdh_client(Kex *); 172 void kexecdh_server(Kex *); 173 void kexc25519_client(Kex *); 174 void kexc25519_server(Kex *); 175 176 void 177 kex_dh_hash(char *, char *, char *, int, char *, int, u_char *, int, 178 BIGNUM *, BIGNUM *, BIGNUM *, u_char **, u_int *); 179 void 180 kexgex_hash(int, char *, char *, char *, int, char *, 181 int, u_char *, int, int, int, int, BIGNUM *, BIGNUM *, BIGNUM *, 182 BIGNUM *, BIGNUM *, u_char **, u_int *); 183 #ifdef OPENSSL_HAS_ECC 184 void 185 kex_ecdh_hash(int, const EC_GROUP *, char *, char *, char *, int, 186 char *, int, u_char *, int, const EC_POINT *, const EC_POINT *, 187 const BIGNUM *, u_char **, u_int *); 188 #endif 189 void 190 kex_c25519_hash(int, char *, char *, char *, int, 191 char *, int, u_char *, int, const u_char *, const u_char *, 192 const u_char *, u_int, u_char **, u_int *); 193 194 #define CURVE25519_SIZE 32 195 void kexc25519_keygen(u_char[CURVE25519_SIZE], u_char[CURVE25519_SIZE]) 196 __attribute__((__bounded__(__minbytes__, 1, CURVE25519_SIZE))) 197 __attribute__((__bounded__(__minbytes__, 2, CURVE25519_SIZE))); 198 void kexc25519_shared_key(const u_char key[CURVE25519_SIZE], 199 const u_char pub[CURVE25519_SIZE], Buffer *out) 200 __attribute__((__bounded__(__minbytes__, 1, CURVE25519_SIZE))) 201 __attribute__((__bounded__(__minbytes__, 2, CURVE25519_SIZE))); 202 203 void 204 derive_ssh1_session_id(BIGNUM *, BIGNUM *, u_int8_t[8], u_int8_t[16]); 205 206 #if defined(DEBUG_KEX) || defined(DEBUG_KEXDH) || defined(DEBUG_KEXECDH) 207 void dump_digest(char *, u_char *, int); 208 #endif 209 210 #endif 211