Annotation of src/usr.bin/ssh/kex.h, Revision 1.119.2.1
1.119.2.1! bluhm 1: /* $OpenBSD: kex.h,v 1.119 2023/08/28 03:28:43 djm Exp $ */
1.12 niklas 2:
1.1 markus 3: /*
1.24 markus 4: * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
1.1 markus 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:
1.65 markus 29: #include "mac.h"
1.99 djm 30: #include "crypto_api.h"
1.109 djm 31:
32: #ifdef WITH_OPENSSL
33: #include <openssl/bn.h>
34: #include <openssl/dh.h>
35: #include <openssl/ec.h>
36: #include <openssl/ecdsa.h>
37: #else /* OPENSSL */
38: #define BIGNUM void
39: #define DH void
40: #define EC_KEY void
41: #define EC_GROUP void
42: #endif /* WITH_OPENSSL */
1.69 markus 43:
1.47 andreas 44: #define KEX_COOKIE_LEN 16
1.14 markus 45:
1.79 djm 46: #define KEX_DH1 "diffie-hellman-group1-sha1"
47: #define KEX_DH14_SHA1 "diffie-hellman-group14-sha1"
48: #define KEX_DH14_SHA256 "diffie-hellman-group14-sha256"
49: #define KEX_DH16_SHA512 "diffie-hellman-group16-sha512"
50: #define KEX_DH18_SHA512 "diffie-hellman-group18-sha512"
51: #define KEX_DHGEX_SHA1 "diffie-hellman-group-exchange-sha1"
52: #define KEX_DHGEX_SHA256 "diffie-hellman-group-exchange-sha256"
53: #define KEX_ECDH_SHA2_NISTP256 "ecdh-sha2-nistp256"
54: #define KEX_ECDH_SHA2_NISTP384 "ecdh-sha2-nistp384"
55: #define KEX_ECDH_SHA2_NISTP521 "ecdh-sha2-nistp521"
56: #define KEX_CURVE25519_SHA256 "curve25519-sha256"
57: #define KEX_CURVE25519_SHA256_OLD "curve25519-sha256@libssh.org"
1.112 djm 58: #define KEX_SNTRUP761X25519_SHA512 "sntrup761x25519-sha512@openssh.com"
1.37 markus 59:
60: #define COMP_NONE 0
1.90 sf 61: /* pre-auth compression (COMP_ZLIB) is only supported in the client */
1.87 sf 62: #define COMP_ZLIB 1
1.88 sf 63: #define COMP_DELAYED 2
1.1 markus 64:
1.69 markus 65: #define CURVE25519_SIZE 32
66:
1.1 markus 67: enum kex_init_proposals {
68: PROPOSAL_KEX_ALGS,
69: PROPOSAL_SERVER_HOST_KEY_ALGS,
70: PROPOSAL_ENC_ALGS_CTOS,
71: PROPOSAL_ENC_ALGS_STOC,
72: PROPOSAL_MAC_ALGS_CTOS,
73: PROPOSAL_MAC_ALGS_STOC,
74: PROPOSAL_COMP_ALGS_CTOS,
75: PROPOSAL_COMP_ALGS_STOC,
76: PROPOSAL_LANG_CTOS,
77: PROPOSAL_LANG_STOC,
78: PROPOSAL_MAX
79: };
80:
81: enum kex_modes {
82: MODE_IN,
83: MODE_OUT,
84: MODE_MAX
85: };
86:
1.5 provos 87: enum kex_exchange {
1.33 markus 88: KEX_DH_GRP1_SHA1,
1.35 djm 89: KEX_DH_GRP14_SHA1,
1.78 djm 90: KEX_DH_GRP14_SHA256,
91: KEX_DH_GRP16_SHA512,
92: KEX_DH_GRP18_SHA512,
1.33 markus 93: KEX_DH_GEX_SHA1,
1.39 djm 94: KEX_DH_GEX_SHA256,
1.50 djm 95: KEX_ECDH_SHA2,
1.57 markus 96: KEX_C25519_SHA256,
1.112 djm 97: KEX_KEM_SNTRUP761X25519_SHA512,
1.33 markus 98: KEX_MAX
1.5 provos 99: };
1.13 stevesk 100:
1.116 djm 101: /* kex->flags */
102: #define KEX_INIT_SENT 0x0001
103: #define KEX_INITIAL 0x0002
104: #define KEX_HAS_PUBKEY_HOSTBOUND 0x0004
1.117 djm 105: #define KEX_RSA_SHA2_256_SUPPORTED 0x0008 /* only set in server for now */
106: #define KEX_RSA_SHA2_512_SUPPORTED 0x0010 /* only set in server for now */
1.119 djm 107: #define KEX_HAS_PING 0x0020
1.19 markus 108:
1.67 markus 109: struct sshenc {
1.19 markus 110: char *name;
1.67 markus 111: const struct sshcipher *cipher;
1.19 markus 112: int enabled;
1.29 markus 113: u_int key_len;
1.54 markus 114: u_int iv_len;
1.29 markus 115: u_int block_size;
1.10 markus 116: u_char *key;
117: u_char *iv;
1.1 markus 118: };
1.67 markus 119: struct sshcomp {
120: u_int type;
1.19 markus 121: int enabled;
122: char *name;
123: };
1.67 markus 124: struct newkeys {
125: struct sshenc enc;
126: struct sshmac mac;
1.69 markus 127: struct sshcomp comp;
1.1 markus 128: };
1.69 markus 129:
130: struct ssh;
1.115 djm 131: struct sshbuf;
1.69 markus 132:
1.67 markus 133: struct kex {
134: struct newkeys *newkeys[MODE_MAX];
1.36 djm 135: u_int we_need;
1.61 dtucker 136: u_int dh_need;
1.19 markus 137: int server;
138: char *name;
1.74 markus 139: char *hostkey_alg;
1.19 markus 140: int hostkey_type;
1.70 djm 141: int hostkey_nid;
1.69 markus 142: u_int kex_type;
1.84 djm 143: char *server_sig_algs;
1.74 markus 144: int ext_info_c;
1.119.2.1! bluhm 145: int kex_strict;
1.67 markus 146: struct sshbuf *my;
147: struct sshbuf *peer;
1.93 djm 148: struct sshbuf *client_version;
149: struct sshbuf *server_version;
1.113 djm 150: struct sshbuf *session_id;
1.115 djm 151: struct sshbuf *initial_sig;
152: struct sshkey *initial_hostkey;
1.42 djm 153: sig_atomic_t done;
1.69 markus 154: u_int flags;
1.59 djm 155: int hash_alg;
1.55 djm 156: int ec_nid;
1.72 djm 157: char *failed_choice;
1.69 markus 158: int (*verify_host_key)(struct sshkey *, struct ssh *);
1.70 djm 159: struct sshkey *(*load_host_public_key)(int, int, struct ssh *);
160: struct sshkey *(*load_host_private_key)(int, int, struct ssh *);
1.71 djm 161: int (*host_key_index)(struct sshkey *, int, struct ssh *);
1.94 djm 162: int (*sign)(struct ssh *, struct sshkey *, struct sshkey *,
163: u_char **, size_t *, const u_char *, size_t, const char *);
1.69 markus 164: int (*kex[KEX_MAX])(struct ssh *);
165: /* kex specific state */
166: DH *dh; /* DH */
167: u_int min, max, nbits; /* GEX */
168: EC_KEY *ec_client_key; /* ECDH */
169: const EC_GROUP *ec_group; /* ECDH */
1.99 djm 170: u_char c25519_client_key[CURVE25519_SIZE]; /* 25519 + KEM */
1.69 markus 171: u_char c25519_client_pubkey[CURVE25519_SIZE]; /* 25519 */
1.112 djm 172: u_char sntrup761_client_key[crypto_kem_sntrup761_SECRETKEYBYTES]; /* KEM */
1.106 djm 173: struct sshbuf *client_pub;
1.1 markus 174: };
1.52 djm 175:
176: int kex_names_valid(const char *);
1.58 dtucker 177: char *kex_alg_list(char);
1.73 djm 178: char *kex_names_cat(const char *, const char *);
1.85 djm 179: int kex_assemble_names(char **, const char *, const char *);
1.118 dtucker 180: void kex_proposal_populate_entries(struct ssh *, char *prop[PROPOSAL_MAX],
181: const char *, const char *, const char *, const char *, const char *);
182: void kex_proposal_free_entries(char *prop[PROPOSAL_MAX]);
1.1 markus 183:
1.93 djm 184: int kex_exchange_identification(struct ssh *, int, const char *);
185:
186: struct kex *kex_new(void);
187: int kex_ready(struct ssh *, char *[PROPOSAL_MAX]);
1.69 markus 188: int kex_setup(struct ssh *, char *[PROPOSAL_MAX]);
189: void kex_free_newkeys(struct newkeys *);
190: void kex_free(struct kex *);
191:
192: int kex_buf2prop(struct sshbuf *, int *, char ***);
193: int kex_prop2buf(struct sshbuf *, char *proposal[PROPOSAL_MAX]);
194: void kex_prop_free(char **);
1.97 djm 195: int kex_load_hostkey(struct ssh *, struct sshkey **, struct sshkey **);
1.98 djm 196: int kex_verify_host_key(struct ssh *, struct sshkey *);
1.20 markus 197:
1.69 markus 198: int kex_send_kexinit(struct ssh *);
1.83 markus 199: int kex_input_kexinit(int, u_int32_t, struct ssh *);
200: int kex_input_ext_info(int, u_int32_t, struct ssh *);
1.114 djm 201: int kex_protocol_error(int, u_int32_t, struct ssh *);
1.69 markus 202: int kex_derive_keys(struct ssh *, u_char *, u_int, const struct sshbuf *);
203: int kex_send_newkeys(struct ssh *);
1.76 djm 204: int kex_start_rekex(struct ssh *);
1.69 markus 205:
206: int kexgex_client(struct ssh *);
207: int kexgex_server(struct ssh *);
1.105 djm 208: int kex_gen_client(struct ssh *);
209: int kex_gen_server(struct ssh *);
1.100 djm 210:
1.101 djm 211: int kex_dh_keypair(struct kex *);
1.104 djm 212: int kex_dh_enc(struct kex *, const struct sshbuf *, struct sshbuf **,
1.101 djm 213: struct sshbuf **);
1.104 djm 214: int kex_dh_dec(struct kex *, const struct sshbuf *, struct sshbuf **);
1.101 djm 215:
1.102 djm 216: int kex_ecdh_keypair(struct kex *);
1.104 djm 217: int kex_ecdh_enc(struct kex *, const struct sshbuf *, struct sshbuf **,
1.102 djm 218: struct sshbuf **);
1.104 djm 219: int kex_ecdh_dec(struct kex *, const struct sshbuf *, struct sshbuf **);
1.102 djm 220:
1.100 djm 221: int kex_c25519_keypair(struct kex *);
1.104 djm 222: int kex_c25519_enc(struct kex *, const struct sshbuf *, struct sshbuf **,
1.100 djm 223: struct sshbuf **);
1.104 djm 224: int kex_c25519_dec(struct kex *, const struct sshbuf *, struct sshbuf **);
1.99 djm 225:
1.112 djm 226: int kex_kem_sntrup761x25519_keypair(struct kex *);
227: int kex_kem_sntrup761x25519_enc(struct kex *, const struct sshbuf *,
1.99 djm 228: struct sshbuf **, struct sshbuf **);
1.112 djm 229: int kex_kem_sntrup761x25519_dec(struct kex *, const struct sshbuf *,
1.99 djm 230: struct sshbuf **);
1.69 markus 231:
1.95 djm 232: int kex_dh_keygen(struct kex *);
1.96 djm 233: int kex_dh_compute_key(struct kex *, BIGNUM *, struct sshbuf *);
1.69 markus 234:
1.93 djm 235: int kexgex_hash(int, const struct sshbuf *, const struct sshbuf *,
1.107 djm 236: const struct sshbuf *, const struct sshbuf *, const struct sshbuf *,
1.69 markus 237: int, int, int,
238: const BIGNUM *, const BIGNUM *, const BIGNUM *,
1.96 djm 239: const BIGNUM *, const u_char *, size_t,
1.69 markus 240: u_char *, size_t *);
1.19 markus 241:
1.69 markus 242: void kexc25519_keygen(u_char key[CURVE25519_SIZE], u_char pub[CURVE25519_SIZE])
1.64 djm 243: __attribute__((__bounded__(__minbytes__, 1, CURVE25519_SIZE)))
244: __attribute__((__bounded__(__minbytes__, 2, CURVE25519_SIZE)));
1.69 markus 245: int kexc25519_shared_key(const u_char key[CURVE25519_SIZE],
246: const u_char pub[CURVE25519_SIZE], struct sshbuf *out)
1.64 djm 247: __attribute__((__bounded__(__minbytes__, 1, CURVE25519_SIZE)))
248: __attribute__((__bounded__(__minbytes__, 2, CURVE25519_SIZE)));
1.99 djm 249: int kexc25519_shared_key_ext(const u_char key[CURVE25519_SIZE],
250: const u_char pub[CURVE25519_SIZE], struct sshbuf *out, int)
251: __attribute__((__bounded__(__minbytes__, 1, CURVE25519_SIZE)))
252: __attribute__((__bounded__(__minbytes__, 2, CURVE25519_SIZE)));
1.18 markus 253:
1.50 djm 254: #if defined(DEBUG_KEX) || defined(DEBUG_KEXDH) || defined(DEBUG_KEXECDH)
1.99 djm 255: void dump_digest(const char *, const u_char *, int);
1.18 markus 256: #endif
1.1 markus 257:
258: #endif