Annotation of src/usr.bin/ssh/kex.h, Revision 1.102
1.102 ! djm 1: /* $OpenBSD: kex.h,v 1.101 2019/01/21 10:28:01 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"
1.47 andreas 31:
1.69 markus 32: #ifdef WITH_LEAKMALLOC
33: #include "leakmalloc.h"
34: #endif
35:
1.47 andreas 36: #define KEX_COOKIE_LEN 16
1.14 markus 37:
1.79 djm 38: #define KEX_DH1 "diffie-hellman-group1-sha1"
39: #define KEX_DH14_SHA1 "diffie-hellman-group14-sha1"
40: #define KEX_DH14_SHA256 "diffie-hellman-group14-sha256"
41: #define KEX_DH16_SHA512 "diffie-hellman-group16-sha512"
42: #define KEX_DH18_SHA512 "diffie-hellman-group18-sha512"
43: #define KEX_DHGEX_SHA1 "diffie-hellman-group-exchange-sha1"
44: #define KEX_DHGEX_SHA256 "diffie-hellman-group-exchange-sha256"
45: #define KEX_ECDH_SHA2_NISTP256 "ecdh-sha2-nistp256"
46: #define KEX_ECDH_SHA2_NISTP384 "ecdh-sha2-nistp384"
47: #define KEX_ECDH_SHA2_NISTP521 "ecdh-sha2-nistp521"
48: #define KEX_CURVE25519_SHA256 "curve25519-sha256"
49: #define KEX_CURVE25519_SHA256_OLD "curve25519-sha256@libssh.org"
1.99 djm 50: #define KEX_SNTRUP4591761X25519_SHA512 "sntrup4591761x25519-sha512@tinyssh.org"
1.37 markus 51:
52: #define COMP_NONE 0
1.90 sf 53: /* pre-auth compression (COMP_ZLIB) is only supported in the client */
1.87 sf 54: #define COMP_ZLIB 1
1.88 sf 55: #define COMP_DELAYED 2
1.1 markus 56:
1.69 markus 57: #define CURVE25519_SIZE 32
58:
1.1 markus 59: enum kex_init_proposals {
60: PROPOSAL_KEX_ALGS,
61: PROPOSAL_SERVER_HOST_KEY_ALGS,
62: PROPOSAL_ENC_ALGS_CTOS,
63: PROPOSAL_ENC_ALGS_STOC,
64: PROPOSAL_MAC_ALGS_CTOS,
65: PROPOSAL_MAC_ALGS_STOC,
66: PROPOSAL_COMP_ALGS_CTOS,
67: PROPOSAL_COMP_ALGS_STOC,
68: PROPOSAL_LANG_CTOS,
69: PROPOSAL_LANG_STOC,
70: PROPOSAL_MAX
71: };
72:
73: enum kex_modes {
74: MODE_IN,
75: MODE_OUT,
76: MODE_MAX
77: };
78:
1.5 provos 79: enum kex_exchange {
1.33 markus 80: KEX_DH_GRP1_SHA1,
1.35 djm 81: KEX_DH_GRP14_SHA1,
1.78 djm 82: KEX_DH_GRP14_SHA256,
83: KEX_DH_GRP16_SHA512,
84: KEX_DH_GRP18_SHA512,
1.33 markus 85: KEX_DH_GEX_SHA1,
1.39 djm 86: KEX_DH_GEX_SHA256,
1.50 djm 87: KEX_ECDH_SHA2,
1.57 markus 88: KEX_C25519_SHA256,
1.99 djm 89: KEX_KEM_SNTRUP4591761X25519_SHA512,
1.33 markus 90: KEX_MAX
1.5 provos 91: };
1.13 stevesk 92:
1.19 markus 93: #define KEX_INIT_SENT 0x0001
1.92 djm 94: #define KEX_INITIAL 0x0002
1.19 markus 95:
1.67 markus 96: struct sshenc {
1.19 markus 97: char *name;
1.67 markus 98: const struct sshcipher *cipher;
1.19 markus 99: int enabled;
1.29 markus 100: u_int key_len;
1.54 markus 101: u_int iv_len;
1.29 markus 102: u_int block_size;
1.10 markus 103: u_char *key;
104: u_char *iv;
1.1 markus 105: };
1.67 markus 106: struct sshcomp {
107: u_int type;
1.19 markus 108: int enabled;
109: char *name;
110: };
1.67 markus 111: struct newkeys {
112: struct sshenc enc;
113: struct sshmac mac;
1.69 markus 114: struct sshcomp comp;
1.1 markus 115: };
1.69 markus 116:
117: struct ssh;
118:
1.67 markus 119: struct kex {
1.19 markus 120: u_char *session_id;
1.67 markus 121: size_t session_id_len;
122: struct newkeys *newkeys[MODE_MAX];
1.36 djm 123: u_int we_need;
1.61 dtucker 124: u_int dh_need;
1.19 markus 125: int server;
126: char *name;
1.74 markus 127: char *hostkey_alg;
1.19 markus 128: int hostkey_type;
1.70 djm 129: int hostkey_nid;
1.69 markus 130: u_int kex_type;
1.84 djm 131: char *server_sig_algs;
1.74 markus 132: int ext_info_c;
1.67 markus 133: struct sshbuf *my;
134: struct sshbuf *peer;
1.93 djm 135: struct sshbuf *client_version;
136: struct sshbuf *server_version;
1.42 djm 137: sig_atomic_t done;
1.69 markus 138: u_int flags;
1.59 djm 139: int hash_alg;
1.55 djm 140: int ec_nid;
1.72 djm 141: char *failed_choice;
1.69 markus 142: int (*verify_host_key)(struct sshkey *, struct ssh *);
1.70 djm 143: struct sshkey *(*load_host_public_key)(int, int, struct ssh *);
144: struct sshkey *(*load_host_private_key)(int, int, struct ssh *);
1.71 djm 145: int (*host_key_index)(struct sshkey *, int, struct ssh *);
1.94 djm 146: int (*sign)(struct ssh *, struct sshkey *, struct sshkey *,
147: u_char **, size_t *, const u_char *, size_t, const char *);
1.69 markus 148: int (*kex[KEX_MAX])(struct ssh *);
149: /* kex specific state */
150: DH *dh; /* DH */
151: u_int min, max, nbits; /* GEX */
152: EC_KEY *ec_client_key; /* ECDH */
153: const EC_GROUP *ec_group; /* ECDH */
1.99 djm 154: u_char c25519_client_key[CURVE25519_SIZE]; /* 25519 + KEM */
1.69 markus 155: u_char c25519_client_pubkey[CURVE25519_SIZE]; /* 25519 */
1.99 djm 156: u_char sntrup4591761_client_key[crypto_kem_sntrup4591761_SECRETKEYBYTES]; /* KEM */
157: struct sshbuf *kem_client_pub; /* KEM */
1.1 markus 158: };
1.52 djm 159:
160: int kex_names_valid(const char *);
1.58 dtucker 161: char *kex_alg_list(char);
1.73 djm 162: char *kex_names_cat(const char *, const char *);
1.85 djm 163: int kex_assemble_names(char **, const char *, const char *);
1.1 markus 164:
1.93 djm 165: int kex_exchange_identification(struct ssh *, int, const char *);
166:
167: struct kex *kex_new(void);
168: int kex_ready(struct ssh *, char *[PROPOSAL_MAX]);
1.69 markus 169: int kex_setup(struct ssh *, char *[PROPOSAL_MAX]);
170: void kex_free_newkeys(struct newkeys *);
171: void kex_free(struct kex *);
172:
173: int kex_buf2prop(struct sshbuf *, int *, char ***);
174: int kex_prop2buf(struct sshbuf *, char *proposal[PROPOSAL_MAX]);
175: void kex_prop_free(char **);
1.97 djm 176: int kex_load_hostkey(struct ssh *, struct sshkey **, struct sshkey **);
1.98 djm 177: int kex_verify_host_key(struct ssh *, struct sshkey *);
1.20 markus 178:
1.69 markus 179: int kex_send_kexinit(struct ssh *);
1.83 markus 180: int kex_input_kexinit(int, u_int32_t, struct ssh *);
181: int kex_input_ext_info(int, u_int32_t, struct ssh *);
1.69 markus 182: int kex_derive_keys(struct ssh *, u_char *, u_int, const struct sshbuf *);
183: int kex_derive_keys_bn(struct ssh *, u_char *, u_int, const BIGNUM *);
184: int kex_send_newkeys(struct ssh *);
1.76 djm 185: int kex_start_rekex(struct ssh *);
1.69 markus 186:
187: int kexdh_client(struct ssh *);
188: int kexdh_server(struct ssh *);
189: int kexgex_client(struct ssh *);
190: int kexgex_server(struct ssh *);
191: int kexecdh_client(struct ssh *);
192: int kexecdh_server(struct ssh *);
193: int kexc25519_client(struct ssh *);
194: int kexc25519_server(struct ssh *);
1.99 djm 195: int kex_kem_client(struct ssh *);
196: int kex_kem_server(struct ssh *);
1.100 djm 197:
1.101 djm 198: int kex_dh_keypair(struct kex *);
199: int kex_dh_enc(struct kex *, const u_char *, size_t, struct sshbuf **,
200: struct sshbuf **);
201: int kex_dh_dec(struct kex *, const u_char *, size_t, struct sshbuf **);
202:
1.102 ! djm 203: int kex_ecdh_keypair(struct kex *);
! 204: int kex_ecdh_enc(struct kex *, const u_char *, size_t, struct sshbuf **,
! 205: struct sshbuf **);
! 206: int kex_ecdh_dec(struct kex *, const u_char *, size_t, struct sshbuf **);
! 207:
1.100 djm 208: int kex_c25519_keypair(struct kex *);
209: int kex_c25519_enc(struct kex *, const u_char *, size_t, struct sshbuf **,
210: struct sshbuf **);
211: int kex_c25519_dec(struct kex *, const u_char *, size_t, struct sshbuf **);
1.99 djm 212:
213: int kex_kem_sntrup4591761x25519_keypair(struct kex *);
214: int kex_kem_sntrup4591761x25519_enc(struct kex *, const u_char *, size_t,
215: struct sshbuf **, struct sshbuf **);
216: int kex_kem_sntrup4591761x25519_dec(struct kex *, const u_char *, size_t,
217: struct sshbuf **);
1.69 markus 218:
1.95 djm 219: int kex_dh_keygen(struct kex *);
1.96 djm 220: int kex_dh_compute_key(struct kex *, BIGNUM *, struct sshbuf *);
1.69 markus 221:
1.93 djm 222: int kexgex_hash(int, const struct sshbuf *, const struct sshbuf *,
1.69 markus 223: const u_char *, size_t, const u_char *, size_t, const u_char *, size_t,
224: int, int, int,
225: const BIGNUM *, const BIGNUM *, const BIGNUM *,
1.96 djm 226: const BIGNUM *, const u_char *, size_t,
1.69 markus 227: u_char *, size_t *);
228:
1.93 djm 229: int kex_c25519_hash(int, const struct sshbuf *, const struct sshbuf *,
1.77 djm 230: const u_char *, size_t, const u_char *, size_t,
1.99 djm 231: const u_char *, size_t, const u_char *, size_t, const u_char *, size_t,
1.69 markus 232: const u_char *, size_t, u_char *, size_t *);
1.19 markus 233:
1.69 markus 234: void kexc25519_keygen(u_char key[CURVE25519_SIZE], u_char pub[CURVE25519_SIZE])
1.64 djm 235: __attribute__((__bounded__(__minbytes__, 1, CURVE25519_SIZE)))
236: __attribute__((__bounded__(__minbytes__, 2, CURVE25519_SIZE)));
1.69 markus 237: int kexc25519_shared_key(const u_char key[CURVE25519_SIZE],
238: const u_char pub[CURVE25519_SIZE], struct sshbuf *out)
1.64 djm 239: __attribute__((__bounded__(__minbytes__, 1, CURVE25519_SIZE)))
240: __attribute__((__bounded__(__minbytes__, 2, CURVE25519_SIZE)));
1.99 djm 241: int kexc25519_shared_key_ext(const u_char key[CURVE25519_SIZE],
242: const u_char pub[CURVE25519_SIZE], struct sshbuf *out, int)
243: __attribute__((__bounded__(__minbytes__, 1, CURVE25519_SIZE)))
244: __attribute__((__bounded__(__minbytes__, 2, CURVE25519_SIZE)));
1.18 markus 245:
1.50 djm 246: #if defined(DEBUG_KEX) || defined(DEBUG_KEXDH) || defined(DEBUG_KEXECDH)
1.99 djm 247: void dump_digest(const char *, const u_char *, int);
1.18 markus 248: #endif
1.1 markus 249:
250: #endif