| /* $OpenBSD: kex.c,v 1.90 2013/04/19 12:07:08 djm Exp $ */ |
| /* |
| * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| #include "includes.h" |
| |
| #include <sys/param.h> |
| |
| #include <signal.h> |
| #include <stdarg.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| |
| #include <openssl/crypto.h> |
| |
| #include "xmalloc.h" |
| #include "ssh2.h" |
| #include "buffer.h" |
| #include "packet.h" |
| #include "compat.h" |
| #include "cipher.h" |
| #include "key.h" |
| #include "kex.h" |
| #include "log.h" |
| #include "mac.h" |
| #include "match.h" |
| #include "dispatch.h" |
| #include "monitor.h" |
| #include "roaming.h" |
| |
| #if OPENSSL_VERSION_NUMBER >= 0x00907000L |
| # if defined(HAVE_EVP_SHA256) |
| # define evp_ssh_sha256 EVP_sha256 |
| # else |
| extern const EVP_MD *evp_ssh_sha256(void); |
| # endif |
| #endif |
| |
| /* prototype */ |
| static void kex_kexinit_finish(Kex *); |
| static void kex_choose_conf(Kex *); |
| |
| struct kexalg { |
| char *name; |
| int type; |
| int ec_nid; |
| const EVP_MD *(*mdfunc)(void); |
| }; |
| static const struct kexalg kexalgs[] = { |
| { KEX_DH1, KEX_DH_GRP1_SHA1, 0, EVP_sha1 }, |
| { KEX_DH14, KEX_DH_GRP14_SHA1, 0, EVP_sha1 }, |
| { KEX_DHGEX_SHA1, KEX_DH_GEX_SHA1, 0, EVP_sha1 }, |
| #if OPENSSL_VERSION_NUMBER >= 0x00907000L |
| { KEX_DHGEX_SHA256, KEX_DH_GEX_SHA256, 0, EVP_sha256 }, |
| { KEX_ECDH_SHA2_NISTP256, KEX_ECDH_SHA2, NID_X9_62_prime256v1, EVP_sha256 }, |
| { KEX_ECDH_SHA2_NISTP384, KEX_ECDH_SHA2, NID_secp384r1, EVP_sha384 }, |
| { KEX_ECDH_SHA2_NISTP521, KEX_ECDH_SHA2, NID_secp521r1, EVP_sha512 }, |
| #endif |
| { NULL, -1, -1, NULL}, |
| }; |
| |
| char * |
| kex_alg_list(void) |
| { |
| char *ret = NULL; |
| size_t nlen, rlen = 0; |
| const struct kexalg *k; |
| |
| for (k = kexalgs; k->name != NULL; k++) { |
| if (ret != NULL) |
| ret[rlen++] = '\n'; |
| nlen = strlen(k->name); |
| ret = xrealloc(ret, 1, rlen + nlen + 2); |
| memcpy(ret + rlen, k->name, nlen + 1); |
| rlen += nlen; |
| } |
| return ret; |
| } |
| |
| static const struct kexalg * |
| kex_alg_by_name(const char *name) |
| { |
| const struct kexalg *k; |
| |
| for (k = kexalgs; k->name != NULL; k++) { |
| if (strcmp(k->name, name) == 0) |
| return k; |
| } |
| return NULL; |
| } |
| |
| /* Validate KEX method name list */ |
| int |
| kex_names_valid(const char *names) |
| { |
| char *s, *cp, *p; |
| |
| if (names == NULL || strcmp(names, "") == 0) |
| return 0; |
| s = cp = xstrdup(names); |
| for ((p = strsep(&cp, ",")); p && *p != '\0'; |
| (p = strsep(&cp, ","))) { |
| if (kex_alg_by_name(p) == NULL) { |
| error("Unsupported KEX algorithm \"%.100s\"", p); |
| xfree(s); |
| return 0; |
| } |
| } |
| debug3("kex names ok: [%s]", names); |
| xfree(s); |
| return 1; |
| } |
| |
| /* put algorithm proposal into buffer */ |
| static void |
| kex_prop2buf(Buffer *b, char *proposal[PROPOSAL_MAX]) |
| { |
| u_int i; |
| |
| buffer_clear(b); |
| /* |
| * add a dummy cookie, the cookie will be overwritten by |
| * kex_send_kexinit(), each time a kexinit is set |
| */ |
| for (i = 0; i < KEX_COOKIE_LEN; i++) |
| buffer_put_char(b, 0); |
| for (i = 0; i < PROPOSAL_MAX; i++) |
| buffer_put_cstring(b, proposal[i]); |
| buffer_put_char(b, 0); /* first_kex_packet_follows */ |
| buffer_put_int(b, 0); /* uint32 reserved */ |
| } |
| |
| /* parse buffer and return algorithm proposal */ |
| static char ** |
| kex_buf2prop(Buffer *raw, int *first_kex_follows) |
| { |
| Buffer b; |
| u_int i; |
| char **proposal; |
| |
| proposal = xcalloc(PROPOSAL_MAX, sizeof(char *)); |
| |
| buffer_init(&b); |
| buffer_append(&b, buffer_ptr(raw), buffer_len(raw)); |
| /* skip cookie */ |
| for (i = 0; i < KEX_COOKIE_LEN; i++) |
| buffer_get_char(&b); |
| /* extract kex init proposal strings */ |
| for (i = 0; i < PROPOSAL_MAX; i++) { |
| proposal[i] = buffer_get_cstring(&b,NULL); |
| debug2("kex_parse_kexinit: %s", proposal[i]); |
| } |
| /* first kex follows / reserved */ |
| i = buffer_get_char(&b); |
| if (first_kex_follows != NULL) |
| *first_kex_follows = i; |
| debug2("kex_parse_kexinit: first_kex_follows %d ", i); |
| i = buffer_get_int(&b); |
| debug2("kex_parse_kexinit: reserved %u ", i); |
| buffer_free(&b); |
| return proposal; |
| } |
| |
| static void |
| kex_prop_free(char **proposal) |
| { |
| u_int i; |
| |
| for (i = 0; i < PROPOSAL_MAX; i++) |
| xfree(proposal[i]); |
| xfree(proposal); |
| } |
| |
| /* ARGSUSED */ |
| static void |
| kex_protocol_error(int type, u_int32_t seq, void *ctxt) |
| { |
| error("Hm, kex protocol error: type %d seq %u", type, seq); |
| } |
| |
| static void |
| kex_reset_dispatch(void) |
| { |
| dispatch_range(SSH2_MSG_TRANSPORT_MIN, |
| SSH2_MSG_TRANSPORT_MAX, &kex_protocol_error); |
| dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit); |
| } |
| |
| void |
| kex_finish(Kex *kex) |
| { |
| kex_reset_dispatch(); |
| |
| packet_start(SSH2_MSG_NEWKEYS); |
| packet_send(); |
| /* packet_write_wait(); */ |
| debug("SSH2_MSG_NEWKEYS sent"); |
| |
| debug("expecting SSH2_MSG_NEWKEYS"); |
| packet_read_expect(SSH2_MSG_NEWKEYS); |
| packet_check_eom(); |
| debug("SSH2_MSG_NEWKEYS received"); |
| |
| kex->done = 1; |
| buffer_clear(&kex->peer); |
| /* buffer_clear(&kex->my); */ |
| kex->flags &= ~KEX_INIT_SENT; |
| xfree(kex->name); |
| kex->name = NULL; |
| } |
| |
| void |
| kex_send_kexinit(Kex *kex) |
| { |
| u_int32_t rnd = 0; |
| u_char *cookie; |
| u_int i; |
| |
| if (kex == NULL) { |
| error("kex_send_kexinit: no kex, cannot rekey"); |
| return; |
| } |
| if (kex->flags & KEX_INIT_SENT) { |
| debug("KEX_INIT_SENT"); |
| return; |
| } |
| kex->done = 0; |
| |
| /* generate a random cookie */ |
| if (buffer_len(&kex->my) < KEX_COOKIE_LEN) |
| fatal("kex_send_kexinit: kex proposal too short"); |
| cookie = buffer_ptr(&kex->my); |
| for (i = 0; i < KEX_COOKIE_LEN; i++) { |
| if (i % 4 == 0) |
| rnd = arc4random(); |
| cookie[i] = rnd; |
| rnd >>= 8; |
| } |
| packet_start(SSH2_MSG_KEXINIT); |
| packet_put_raw(buffer_ptr(&kex->my), buffer_len(&kex->my)); |
| packet_send(); |
| debug("SSH2_MSG_KEXINIT sent"); |
| kex->flags |= KEX_INIT_SENT; |
| } |
| |
| /* ARGSUSED */ |
| void |
| kex_input_kexinit(int type, u_int32_t seq, void *ctxt) |
| { |
| char *ptr; |
| u_int i, dlen; |
| Kex *kex = (Kex *)ctxt; |
| |
| debug("SSH2_MSG_KEXINIT received"); |
| if (kex == NULL) |
| fatal("kex_input_kexinit: no kex, cannot rekey"); |
| |
| ptr = packet_get_raw(&dlen); |
| buffer_append(&kex->peer, ptr, dlen); |
| |
| /* discard packet */ |
| for (i = 0; i < KEX_COOKIE_LEN; i++) |
| packet_get_char(); |
| for (i = 0; i < PROPOSAL_MAX; i++) |
| xfree(packet_get_string(NULL)); |
| /* |
| * XXX RFC4253 sec 7: "each side MAY guess" - currently no supported |
| * KEX method has the server move first, but a server might be using |
| * a custom method or one that we otherwise don't support. We should |
| * be prepared to remember first_kex_follows here so we can eat a |
| * packet later. |
| * XXX2 - RFC4253 is kind of ambiguous on what first_kex_follows means |
| * for cases where the server *doesn't* go first. I guess we should |
| * ignore it when it is set for these cases, which is what we do now. |
| */ |
| (void) packet_get_char(); /* first_kex_follows */ |
| (void) packet_get_int(); /* reserved */ |
| packet_check_eom(); |
| |
| kex_kexinit_finish(kex); |
| } |
| |
| Kex * |
| kex_setup(char *proposal[PROPOSAL_MAX]) |
| { |
| Kex *kex; |
| |
| kex = xcalloc(1, sizeof(*kex)); |
| buffer_init(&kex->peer); |
| buffer_init(&kex->my); |
| kex_prop2buf(&kex->my, proposal); |
| kex->done = 0; |
| |
| kex_send_kexinit(kex); /* we start */ |
| kex_reset_dispatch(); |
| |
| return kex; |
| } |
| |
| static void |
| kex_kexinit_finish(Kex *kex) |
| { |
| if (!(kex->flags & KEX_INIT_SENT)) |
| kex_send_kexinit(kex); |
| |
| kex_choose_conf(kex); |
| |
| if (kex->kex_type >= 0 && kex->kex_type < KEX_MAX && |
| kex->kex[kex->kex_type] != NULL) { |
| (kex->kex[kex->kex_type])(kex); |
| } else { |
| fatal("Unsupported key exchange %d", kex->kex_type); |
| } |
| } |
| |
| static void |
| choose_enc(Enc *enc, char *client, char *server) |
| { |
| char *name = match_list(client, server, NULL); |
| if (name == NULL) |
| fatal("no matching cipher found: client %s server %s", |
| client, server); |
| if ((enc->cipher = cipher_by_name(name)) == NULL) |
| fatal("matching cipher is not supported: %s", name); |
| enc->name = name; |
| enc->enabled = 0; |
| enc->iv = NULL; |
| enc->iv_len = cipher_ivlen(enc->cipher); |
| enc->key = NULL; |
| enc->key_len = cipher_keylen(enc->cipher); |
| enc->block_size = cipher_blocksize(enc->cipher); |
| } |
| |
| static void |
| choose_mac(Mac *mac, char *client, char *server) |
| { |
| char *name = match_list(client, server, NULL); |
| if (name == NULL) |
| fatal("no matching mac found: client %s server %s", |
| client, server); |
| if (mac_setup(mac, name) < 0) |
| fatal("unsupported mac %s", name); |
| /* truncate the key */ |
| if (datafellows & SSH_BUG_HMAC) |
| mac->key_len = 16; |
| mac->name = name; |
| mac->key = NULL; |
| mac->enabled = 0; |
| } |
| |
| static void |
| choose_comp(Comp *comp, char *client, char *server) |
| { |
| char *name = match_list(client, server, NULL); |
| if (name == NULL) |
| fatal("no matching comp found: client %s server %s", client, server); |
| if (strcmp(name, "zlib@openssh.com") == 0) { |
| comp->type = COMP_DELAYED; |
| } else if (strcmp(name, "zlib") == 0) { |
| comp->type = COMP_ZLIB; |
| } else if (strcmp(name, "none") == 0) { |
| comp->type = COMP_NONE; |
| } else { |
| fatal("unsupported comp %s", name); |
| } |
| comp->name = name; |
| } |
| |
| static void |
| choose_kex(Kex *k, char *client, char *server) |
| { |
| const struct kexalg *kexalg; |
| |
| k->name = match_list(client, server, NULL); |
| if (k->name == NULL) |
| fatal("Unable to negotiate a key exchange method"); |
| if ((kexalg = kex_alg_by_name(k->name)) == NULL) |
| fatal("unsupported kex alg %s", k->name); |
| k->kex_type = kexalg->type; |
| k->evp_md = kexalg->mdfunc(); |
| k->ec_nid = kexalg->ec_nid; |
| } |
| |
| static void |
| choose_hostkeyalg(Kex *k, char *client, char *server) |
| { |
| char *hostkeyalg = match_list(client, server, NULL); |
| if (hostkeyalg == NULL) |
| fatal("no hostkey alg"); |
| k->hostkey_type = key_type_from_name(hostkeyalg); |
| if (k->hostkey_type == KEY_UNSPEC) |
| fatal("bad hostkey alg '%s'", hostkeyalg); |
| xfree(hostkeyalg); |
| } |
| |
| static int |
| proposals_match(char *my[PROPOSAL_MAX], char *peer[PROPOSAL_MAX]) |
| { |
| static int check[] = { |
| PROPOSAL_KEX_ALGS, PROPOSAL_SERVER_HOST_KEY_ALGS, -1 |
| }; |
| int *idx; |
| char *p; |
| |
| for (idx = &check[0]; *idx != -1; idx++) { |
| if ((p = strchr(my[*idx], ',')) != NULL) |
| *p = '\0'; |
| if ((p = strchr(peer[*idx], ',')) != NULL) |
| *p = '\0'; |
| if (strcmp(my[*idx], peer[*idx]) != 0) { |
| debug2("proposal mismatch: my %s peer %s", |
| my[*idx], peer[*idx]); |
| return (0); |
| } |
| } |
| debug2("proposals match"); |
| return (1); |
| } |
| |
| static void |
| kex_choose_conf(Kex *kex) |
| { |
| Newkeys *newkeys; |
| char **my, **peer; |
| char **cprop, **sprop; |
| int nenc, nmac, ncomp; |
| u_int mode, ctos, need, authlen; |
| int first_kex_follows, type; |
| |
| my = kex_buf2prop(&kex->my, NULL); |
| peer = kex_buf2prop(&kex->peer, &first_kex_follows); |
| |
| if (kex->server) { |
| cprop=peer; |
| sprop=my; |
| } else { |
| cprop=my; |
| sprop=peer; |
| } |
| |
| /* Check whether server offers roaming */ |
| if (!kex->server) { |
| char *roaming; |
| roaming = match_list(KEX_RESUME, peer[PROPOSAL_KEX_ALGS], NULL); |
| if (roaming) { |
| kex->roaming = 1; |
| xfree(roaming); |
| } |
| } |
| |
| /* Algorithm Negotiation */ |
| for (mode = 0; mode < MODE_MAX; mode++) { |
| newkeys = xcalloc(1, sizeof(*newkeys)); |
| kex->newkeys[mode] = newkeys; |
| ctos = (!kex->server && mode == MODE_OUT) || |
| (kex->server && mode == MODE_IN); |
| nenc = ctos ? PROPOSAL_ENC_ALGS_CTOS : PROPOSAL_ENC_ALGS_STOC; |
| nmac = ctos ? PROPOSAL_MAC_ALGS_CTOS : PROPOSAL_MAC_ALGS_STOC; |
| ncomp = ctos ? PROPOSAL_COMP_ALGS_CTOS : PROPOSAL_COMP_ALGS_STOC; |
| choose_enc(&newkeys->enc, cprop[nenc], sprop[nenc]); |
| /* ignore mac for authenticated encryption */ |
| authlen = cipher_authlen(newkeys->enc.cipher); |
| if (authlen == 0) |
| choose_mac(&newkeys->mac, cprop[nmac], sprop[nmac]); |
| choose_comp(&newkeys->comp, cprop[ncomp], sprop[ncomp]); |
| debug("kex: %s %s %s %s", |
| ctos ? "client->server" : "server->client", |
| newkeys->enc.name, |
| authlen == 0 ? newkeys->mac.name : "<implicit>", |
| newkeys->comp.name); |
| } |
| choose_kex(kex, cprop[PROPOSAL_KEX_ALGS], sprop[PROPOSAL_KEX_ALGS]); |
| choose_hostkeyalg(kex, cprop[PROPOSAL_SERVER_HOST_KEY_ALGS], |
| sprop[PROPOSAL_SERVER_HOST_KEY_ALGS]); |
| need = 0; |
| for (mode = 0; mode < MODE_MAX; mode++) { |
| newkeys = kex->newkeys[mode]; |
| if (need < newkeys->enc.key_len) |
| need = newkeys->enc.key_len; |
| if (need < newkeys->enc.block_size) |
| need = newkeys->enc.block_size; |
| if (need < newkeys->enc.iv_len) |
| need = newkeys->enc.iv_len; |
| if (need < newkeys->mac.key_len) |
| need = newkeys->mac.key_len; |
| } |
| /* XXX need runden? */ |
| kex->we_need = need; |
| |
| /* ignore the next message if the proposals do not match */ |
| if (first_kex_follows && !proposals_match(my, peer) && |
| !(datafellows & SSH_BUG_FIRSTKEX)) { |
| type = packet_read(); |
| debug2("skipping next packet (type %u)", type); |
| } |
| |
| kex_prop_free(my); |
| kex_prop_free(peer); |
| } |
| |
| static u_char * |
| derive_key(Kex *kex, int id, u_int need, u_char *hash, u_int hashlen, |
| BIGNUM *shared_secret) |
| { |
| Buffer b; |
| EVP_MD_CTX md; |
| char c = id; |
| u_int have; |
| int mdsz; |
| u_char *digest; |
| |
| if ((mdsz = EVP_MD_size(kex->evp_md)) <= 0) |
| fatal("bad kex md size %d", mdsz); |
| digest = xmalloc(roundup(need, mdsz)); |
| |
| buffer_init(&b); |
| buffer_put_bignum2(&b, shared_secret); |
| |
| /* K1 = HASH(K || H || "A" || session_id) */ |
| EVP_DigestInit(&md, kex->evp_md); |
| if (!(datafellows & SSH_BUG_DERIVEKEY)) |
| EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b)); |
| EVP_DigestUpdate(&md, hash, hashlen); |
| EVP_DigestUpdate(&md, &c, 1); |
| EVP_DigestUpdate(&md, kex->session_id, kex->session_id_len); |
| EVP_DigestFinal(&md, digest, NULL); |
| |
| /* |
| * expand key: |
| * Kn = HASH(K || H || K1 || K2 || ... || Kn-1) |
| * Key = K1 || K2 || ... || Kn |
| */ |
| for (have = mdsz; need > have; have += mdsz) { |
| EVP_DigestInit(&md, kex->evp_md); |
| if (!(datafellows & SSH_BUG_DERIVEKEY)) |
| EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b)); |
| EVP_DigestUpdate(&md, hash, hashlen); |
| EVP_DigestUpdate(&md, digest, have); |
| EVP_DigestFinal(&md, digest + have, NULL); |
| } |
| buffer_free(&b); |
| #ifdef DEBUG_KEX |
| fprintf(stderr, "key '%c'== ", c); |
| dump_digest("key", digest, need); |
| #endif |
| return digest; |
| } |
| |
| Newkeys *current_keys[MODE_MAX]; |
| |
| #define NKEYS 6 |
| void |
| kex_derive_keys(Kex *kex, u_char *hash, u_int hashlen, BIGNUM *shared_secret) |
| { |
| u_char *keys[NKEYS]; |
| u_int i, mode, ctos; |
| |
| for (i = 0; i < NKEYS; i++) { |
| keys[i] = derive_key(kex, 'A'+i, kex->we_need, hash, hashlen, |
| shared_secret); |
| } |
| |
| debug2("kex_derive_keys"); |
| for (mode = 0; mode < MODE_MAX; mode++) { |
| current_keys[mode] = kex->newkeys[mode]; |
| kex->newkeys[mode] = NULL; |
| ctos = (!kex->server && mode == MODE_OUT) || |
| (kex->server && mode == MODE_IN); |
| current_keys[mode]->enc.iv = keys[ctos ? 0 : 1]; |
| current_keys[mode]->enc.key = keys[ctos ? 2 : 3]; |
| current_keys[mode]->mac.key = keys[ctos ? 4 : 5]; |
| } |
| } |
| |
| Newkeys * |
| kex_get_newkeys(int mode) |
| { |
| Newkeys *ret; |
| |
| ret = current_keys[mode]; |
| current_keys[mode] = NULL; |
| return ret; |
| } |
| |
| void |
| derive_ssh1_session_id(BIGNUM *host_modulus, BIGNUM *server_modulus, |
| u_int8_t cookie[8], u_int8_t id[16]) |
| { |
| const EVP_MD *evp_md = EVP_md5(); |
| EVP_MD_CTX md; |
| u_int8_t nbuf[2048], obuf[EVP_MAX_MD_SIZE]; |
| int len; |
| |
| EVP_DigestInit(&md, evp_md); |
| |
| len = BN_num_bytes(host_modulus); |
| if (len < (512 / 8) || (u_int)len > sizeof(nbuf)) |
| fatal("%s: bad host modulus (len %d)", __func__, len); |
| BN_bn2bin(host_modulus, nbuf); |
| EVP_DigestUpdate(&md, nbuf, len); |
| |
| len = BN_num_bytes(server_modulus); |
| if (len < (512 / 8) || (u_int)len > sizeof(nbuf)) |
| fatal("%s: bad server modulus (len %d)", __func__, len); |
| BN_bn2bin(server_modulus, nbuf); |
| EVP_DigestUpdate(&md, nbuf, len); |
| |
| EVP_DigestUpdate(&md, cookie, 8); |
| |
| EVP_DigestFinal(&md, obuf, NULL); |
| memcpy(id, obuf, 16); |
| |
| memset(nbuf, 0, sizeof(nbuf)); |
| memset(obuf, 0, sizeof(obuf)); |
| memset(&md, 0, sizeof(md)); |
| } |
| |
| #if defined(DEBUG_KEX) || defined(DEBUG_KEXDH) || defined(DEBUG_KEXECDH) |
| void |
| dump_digest(char *msg, u_char *digest, int len) |
| { |
| int i; |
| |
| fprintf(stderr, "%s\n", msg); |
| for (i = 0; i < len; i++) { |
| fprintf(stderr, "%02x", digest[i]); |
| if (i%32 == 31) |
| fprintf(stderr, "\n"); |
| else if (i%8 == 7) |
| fprintf(stderr, " "); |
| } |
| fprintf(stderr, "\n"); |
| } |
| #endif |