SSH2_PKTCTX_NOKEX,
SSH2_PKTCTX_DHGROUP,
SSH2_PKTCTX_DHGEX,
+ SSH2_PKTCTX_ECDHKEX,
SSH2_PKTCTX_RSAKEX
} Pkt_KCtx;
typedef enum {
translatek(SSH2_MSG_KEXRSA_PUBKEY, SSH2_PKTCTX_RSAKEX);
translatek(SSH2_MSG_KEXRSA_SECRET, SSH2_PKTCTX_RSAKEX);
translatek(SSH2_MSG_KEXRSA_DONE, SSH2_PKTCTX_RSAKEX);
+ translatek(SSH2_MSG_KEX_ECDH_INIT, SSH2_PKTCTX_ECDHKEX);
+ translatek(SSH2_MSG_KEX_ECDH_REPLY, SSH2_PKTCTX_ECDHKEX);
translate(SSH2_MSG_USERAUTH_REQUEST);
translate(SSH2_MSG_USERAUTH_FAILURE);
translate(SSH2_MSG_USERAUTH_SUCCESS);
#define OUR_V2_MAXPKT 0x4000UL
#define OUR_V2_PACKETLIMIT 0x9000UL
-const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
+const static struct ssh_signkey *hostkey_algs[] = {
+ &ssh_ecdsa_nistp256, &ssh_ecdsa_nistp384, &ssh_ecdsa_nistp521,
+ &ssh_rsa, &ssh_dss
+};
const static struct ssh_mac *macs[] = {
&ssh_hmac_sha256, &ssh_hmac_sha1, &ssh_hmac_sha1_96, &ssh_hmac_md5
sfree(error);
}
+int verify_ssh_manual_host_key(Ssh ssh, const char *fingerprint,
+ const struct ssh_signkey *ssh2keytype,
+ void *ssh2keydata)
+{
+ if (!conf_get_str_nthstrkey(ssh->conf, CONF_ssh_manual_hostkeys, 0)) {
+ return -1; /* no manual keys configured */
+ }
+
+ if (fingerprint) {
+ /*
+ * The fingerprint string we've been given will have things
+ * like 'ssh-rsa 2048' at the front of it. Strip those off and
+ * narrow down to just the colon-separated hex block at the
+ * end of the string.
+ */
+ const char *p = strrchr(fingerprint, ' ');
+ fingerprint = p ? p+1 : fingerprint;
+ /* Quick sanity checks, including making sure it's in lowercase */
+ assert(strlen(fingerprint) == 16*3 - 1);
+ assert(fingerprint[2] == ':');
+ assert(fingerprint[strspn(fingerprint, "0123456789abcdef:")] == 0);
+
+ if (conf_get_str_str_opt(ssh->conf, CONF_ssh_manual_hostkeys,
+ fingerprint))
+ return 1; /* success */
+ }
+
+ if (ssh2keydata) {
+ /*
+ * Construct the base64-encoded public key blob and see if
+ * that's listed.
+ */
+ unsigned char *binblob;
+ char *base64blob;
+ int binlen, atoms, i;
+ binblob = ssh2keytype->public_blob(ssh2keydata, &binlen);
+ atoms = (binlen + 2) / 3;
+ base64blob = snewn(atoms * 4 + 1, char);
+ for (i = 0; i < atoms; i++)
+ base64_encode_atom(binblob + 3*i, binlen - 3*i, base64blob + 4*i);
+ base64blob[atoms * 4] = '\0';
+ sfree(binblob);
+ if (conf_get_str_str_opt(ssh->conf, CONF_ssh_manual_hostkeys,
+ base64blob)) {
+ sfree(base64blob);
+ return 1; /* success */
+ }
+ sfree(base64blob);
+ }
+
+ return 0;
+}
+
/*
* Handle the key exchange and user authentication phases.
*/
rsastr_fmt(keystr, &s->hostkey);
rsa_fingerprint(fingerprint, sizeof(fingerprint), &s->hostkey);
- ssh_set_frozen(ssh, 1);
- s->dlgret = verify_ssh_host_key(ssh->frontend,
- ssh->savedhost, ssh->savedport,
- "rsa", keystr, fingerprint,
- ssh_dialog_callback, ssh);
- sfree(keystr);
- if (s->dlgret < 0) {
- do {
- crReturn(0);
- if (pktin) {
- bombout(("Unexpected data from server while waiting"
- " for user host key response"));
- crStop(0);
- }
- } while (pktin || inlen > 0);
- s->dlgret = ssh->user_response;
- }
- ssh_set_frozen(ssh, 0);
+ /* First check against manually configured host keys. */
+ s->dlgret = verify_ssh_manual_host_key(ssh, fingerprint, NULL, NULL);
+ if (s->dlgret == 0) { /* did not match */
+ bombout(("Host key did not appear in manually configured list"));
+ crStop(0);
+ } else if (s->dlgret < 0) { /* none configured; use standard handling */
+ ssh_set_frozen(ssh, 1);
+ s->dlgret = verify_ssh_host_key(ssh->frontend,
+ ssh->savedhost, ssh->savedport,
+ "rsa", keystr, fingerprint,
+ ssh_dialog_callback, ssh);
+ sfree(keystr);
+ if (s->dlgret < 0) {
+ do {
+ crReturn(0);
+ if (pktin) {
+ bombout(("Unexpected data from server while waiting"
+ " for user host key response"));
+ crStop(0);
+ }
+ } while (pktin || inlen > 0);
+ s->dlgret = ssh->user_response;
+ }
+ ssh_set_frozen(ssh, 0);
- if (s->dlgret == 0) {
- ssh_disconnect(ssh, "User aborted at host key verification",
- NULL, 0, TRUE);
- crStop(0);
+ if (s->dlgret == 0) {
+ ssh_disconnect(ssh, "User aborted at host key verification",
+ NULL, 0, TRUE);
+ crStop(0);
+ }
}
}
int hostkeylen, siglen, rsakeylen;
void *hkey; /* actual host key */
void *rsakey; /* for RSA kex */
+ void *eckey; /* for ECDH kex */
unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN];
int n_preferred_kex;
const struct ssh_kexes *preferred_kex[KEX_MAX];
s->preferred_kex[s->n_preferred_kex++] =
&ssh_rsa_kex;
break;
+ case KEX_ECDH:
+ s->preferred_kex[s->n_preferred_kex++] =
+ &ssh_ecdh_kex;
+ break;
case KEX_WARN:
/* Flag for later. Don't bother if it's the last in
* the list. */
pktin->savedpos += 16; /* skip garbage cookie */
ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
+ if (!str) {
+ bombout(("KEXINIT packet was incomplete"));
+ crStopV;
+ }
preferred = NULL;
for (i = 0; i < s->n_preferred_kex; i++) {
break;
}
if (!ssh->kex) {
- bombout(("Couldn't agree a key exchange algorithm (available: %s)",
- str ? str : "(null)"));
+ bombout(("Couldn't agree a key exchange algorithm"
+ " (available: %.*s)", len, str));
crStopV;
}
/*
*/
s->guessok = first_in_commasep_string(preferred, str, len);
ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
+ if (!str) {
+ bombout(("KEXINIT packet was incomplete"));
+ crStopV;
+ }
for (i = 0; i < lenof(hostkey_algs); i++) {
if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
ssh->hostkey = hostkey_algs[i];
}
}
if (!ssh->hostkey) {
- bombout(("Couldn't agree a host key algorithm (available: %s)",
- str ? str : "(null)"));
+ bombout(("Couldn't agree a host key algorithm"
+ " (available: %.*s)", len, str));
crStopV;
}
s->guessok = s->guessok &&
first_in_commasep_string(hostkey_algs[0]->name, str, len);
ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
+ if (!str) {
+ bombout(("KEXINIT packet was incomplete"));
+ crStopV;
+ }
for (i = 0; i < s->n_preferred_ciphers; i++) {
const struct ssh2_ciphers *c = s->preferred_ciphers[i];
if (!c) {
break;
}
if (!s->cscipher_tobe) {
- bombout(("Couldn't agree a client-to-server cipher (available: %s)",
- str ? str : "(null)"));
+ bombout(("Couldn't agree a client-to-server cipher"
+ " (available: %.*s)", len, str));
crStopV;
}
ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
+ if (!str) {
+ bombout(("KEXINIT packet was incomplete"));
+ crStopV;
+ }
for (i = 0; i < s->n_preferred_ciphers; i++) {
const struct ssh2_ciphers *c = s->preferred_ciphers[i];
if (!c) {
break;
}
if (!s->sccipher_tobe) {
- bombout(("Couldn't agree a server-to-client cipher (available: %s)",
- str ? str : "(null)"));
+ bombout(("Couldn't agree a server-to-client cipher"
+ " (available: %.*s)", len, str));
crStopV;
}
ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
+ if (!str) {
+ bombout(("KEXINIT packet was incomplete"));
+ crStopV;
+ }
for (i = 0; i < s->nmacs; i++) {
if (in_commasep_string(s->maclist[i]->name, str, len)) {
s->csmac_tobe = s->maclist[i];
}
}
ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
+ if (!str) {
+ bombout(("KEXINIT packet was incomplete"));
+ crStopV;
+ }
for (i = 0; i < s->nmacs; i++) {
if (in_commasep_string(s->maclist[i]->name, str, len)) {
s->scmac_tobe = s->maclist[i];
}
}
ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
+ if (!str) {
+ bombout(("KEXINIT packet was incomplete"));
+ crStopV;
+ }
for (i = 0; i < lenof(compressions) + 1; i++) {
const struct ssh_compress *c =
i == 0 ? s->preferred_comp : compressions[i - 1];
}
}
ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
+ if (!str) {
+ bombout(("KEXINIT packet was incomplete"));
+ crStopV;
+ }
for (i = 0; i < lenof(compressions) + 1; i++) {
const struct ssh_compress *c =
i == 0 ? s->preferred_comp : compressions[i - 1];
freebn(s->g);
freebn(s->p);
}
+ } else if (ssh->kex->main_type == KEXTYPE_ECDH) {
+
+ logeventf(ssh, "Doing ECDH key exchange with hash %s",
+ ssh->kex->hash->text_name);
+ ssh->pkt_kctx = SSH2_PKTCTX_ECDHKEX;
+
+ s->eckey = NULL;
+ if (!strcmp(ssh->kex->name, "ecdh-sha2-nistp256")) {
+ s->eckey = ssh_ecdhkex_newkey(ec_p256());
+ } else if (!strcmp(ssh->kex->name, "ecdh-sha2-nistp384")) {
+ s->eckey = ssh_ecdhkex_newkey(ec_p384());
+ } else if (!strcmp(ssh->kex->name, "ecdh-sha2-nistp521")) {
+ s->eckey = ssh_ecdhkex_newkey(ec_p521());
+ }
+ if (!s->eckey) {
+ bombout(("Unable to generate key for ECDH"));
+ crStopV;
+ }
+
+ {
+ char *publicPoint;
+ int publicPointLength;
+ publicPoint = ssh_ecdhkex_getpublic(s->eckey, &publicPointLength);
+ if (!publicPoint) {
+ ssh_ecdhkex_freekey(s->eckey);
+ bombout(("Unable to encode public key for ECDH"));
+ crStopV;
+ }
+ s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_ECDH_INIT);
+ ssh2_pkt_addstring_start(s->pktout);
+ ssh2_pkt_addstring_data(s->pktout, publicPoint, publicPointLength);
+ sfree(publicPoint);
+ }
+
+ ssh2_pkt_send_noqueue(ssh, s->pktout);
+
+ crWaitUntilV(pktin);
+ if (pktin->type != SSH2_MSG_KEX_ECDH_REPLY) {
+ ssh_ecdhkex_freekey(s->eckey);
+ bombout(("expected ECDH reply packet from server"));
+ crStopV;
+ }
+
+ ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
+ hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
+ s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
+
+ {
+ char *publicPoint;
+ int publicPointLength;
+ publicPoint = ssh_ecdhkex_getpublic(s->eckey, &publicPointLength);
+ if (!publicPoint) {
+ ssh_ecdhkex_freekey(s->eckey);
+ bombout(("Unable to encode public key for ECDH hash"));
+ crStopV;
+ }
+ hash_string(ssh->kex->hash, ssh->exhash,
+ publicPoint, publicPointLength);
+ sfree(publicPoint);
+ }
+
+ {
+ char *keydata;
+ int keylen;
+ ssh_pkt_getstring(pktin, &keydata, &keylen);
+ hash_string(ssh->kex->hash, ssh->exhash, keydata, keylen);
+ s->K = ssh_ecdhkex_getkey(s->eckey, keydata, keylen);
+ if (!s->K) {
+ ssh_ecdhkex_freekey(s->eckey);
+ bombout(("point received in ECDH was not valid"));
+ crStopV;
+ }
+ }
+
+ ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
+
+ ssh_ecdhkex_freekey(s->eckey);
} else {
logeventf(ssh, "Doing RSA key exchange with hash %s",
ssh->kex->hash->text_name);
* checked the signature of the exchange hash.)
*/
s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
- ssh_set_frozen(ssh, 1);
- s->dlgret = verify_ssh_host_key(ssh->frontend,
- ssh->savedhost, ssh->savedport,
- ssh->hostkey->keytype, s->keystr,
- s->fingerprint,
- ssh_dialog_callback, ssh);
- if (s->dlgret < 0) {
- do {
- crReturnV;
- if (pktin) {
- bombout(("Unexpected data from server while waiting"
- " for user host key response"));
- crStopV;
- }
- } while (pktin || inlen > 0);
- s->dlgret = ssh->user_response;
- }
- ssh_set_frozen(ssh, 0);
- if (s->dlgret == 0) {
- ssh_disconnect(ssh, "User aborted at host key verification", NULL,
- 0, TRUE);
- crStopV;
- }
logevent("Host key fingerprint is:");
logevent(s->fingerprint);
+ /* First check against manually configured host keys. */
+ s->dlgret = verify_ssh_manual_host_key(ssh, s->fingerprint,
+ ssh->hostkey, s->hkey);
+ if (s->dlgret == 0) { /* did not match */
+ bombout(("Host key did not appear in manually configured list"));
+ crStopV;
+ } else if (s->dlgret < 0) { /* none configured; use standard handling */
+ ssh_set_frozen(ssh, 1);
+ s->dlgret = verify_ssh_host_key(ssh->frontend,
+ ssh->savedhost, ssh->savedport,
+ ssh->hostkey->keytype, s->keystr,
+ s->fingerprint,
+ ssh_dialog_callback, ssh);
+ if (s->dlgret < 0) {
+ do {
+ crReturnV;
+ if (pktin) {
+ bombout(("Unexpected data from server while waiting"
+ " for user host key response"));
+ crStopV;
+ }
+ } while (pktin || inlen > 0);
+ s->dlgret = ssh->user_response;
+ }
+ ssh_set_frozen(ssh, 0);
+ if (s->dlgret == 0) {
+ ssh_disconnect(ssh, "Aborted at host key verification", NULL,
+ 0, TRUE);
+ crStopV;
+ }
+ }
sfree(s->fingerprint);
/*
* Save this host key, to check against the one presented in
ssh->gsslibs = NULL;
#endif
+ random_ref(); /* do this now - may be needed by sharing setup code */
+
p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
- if (p != NULL)
+ if (p != NULL) {
+ random_unref();
return p;
-
- random_ref();
+ }
return NULL;
}
projects / PuTTY.git / blobdiff