* Packet type contexts, so that ssh2_pkt_type can correctly decode
* the ambiguous type numbers back into the correct type strings.
*/
-#define SSH2_PKTCTX_DHGROUP1 0x0001
+#define SSH2_PKTCTX_DHGROUP 0x0001
#define SSH2_PKTCTX_DHGEX 0x0002
#define SSH2_PKTCTX_PUBLICKEY 0x0010
#define SSH2_PKTCTX_PASSWORD 0x0020
#define BUG_CHOKES_ON_RSA 8
#define BUG_SSH2_RSA_PADDING 16
#define BUG_SSH2_DERIVEKEY 32
-#define BUG_SSH2_DH_GEX 64
+/* 64 was BUG_SSH2_DH_GEX, now spare */
#define BUG_SSH2_PK_SESSIONID 128
#define translate(x) if (type == x) return #x
translate(SSH2_MSG_SERVICE_ACCEPT);
translate(SSH2_MSG_KEXINIT);
translate(SSH2_MSG_NEWKEYS);
- translatec(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP1);
- translatec(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP1);
+ translatec(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP);
+ translatec(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP);
translatec(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
translatec(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
translatec(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
#define SSH_MAX_BACKLOG 32768
#define OUR_V2_WINSIZE 16384
-const static struct ssh_kex *kex_algs[] = {
- &ssh_diffiehellman_gex,
- &ssh_diffiehellman
-};
-
const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
static void *nullmac_make_context(void)
ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
logevent("We believe remote version has SSH2 public-key-session-ID bug");
}
+}
- if (ssh->cfg.sshbug_dhgex2 == FORCE_ON) {
- /*
- * User specified the SSH2 DH GEX bug.
- */
- ssh->remote_bugs |= BUG_SSH2_DH_GEX;
- logevent("We believe remote version has SSH2 DH group exchange bug");
+/*
+ * The `software version' part of an SSH version string is required
+ * to contain no spaces or minus signs.
+ */
+static void ssh_fix_verstring(char *str)
+{
+ /* Eat "SSH-<protoversion>-". */
+ assert(*str == 'S'); str++;
+ assert(*str == 'S'); str++;
+ assert(*str == 'H'); str++;
+ assert(*str == '-'); str++;
+ while (*str && *str != '-') str++;
+ assert(*str == '-'); str++;
+
+ /* Convert minus signs and spaces in the remaining string into
+ * underscores. */
+ while (*str) {
+ if (*str == '-' || *str == ' ')
+ *str = '_';
+ str++;
}
}
ssh->rdpkt2_state.incoming_sequence = 0;
s->vstring[s->vslen] = 0;
- s->vstring[strcspn(s->vstring, "\r\n")] = '\0';/* remove EOL chars */
+ s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
{
char *vlog;
vlog = snewn(20 + s->vslen, char);
crStop(0);
}
- if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) {
- /*
- * Use v2 protocol.
- */
- char verstring[80], vlog[100];
- sprintf(verstring, "SSH-2.0-%s", sshver);
- SHA_Init(&ssh->exhashbase);
- /*
- * Hash our version string and their version string.
- */
- sha_string(&ssh->exhashbase, verstring, strlen(verstring));
- sha_string(&ssh->exhashbase, s->vstring, strcspn(s->vstring, "\r\n"));
- sprintf(vlog, "We claim version: %s", verstring);
- logevent(vlog);
- strcat(verstring, "\012");
- logevent("Using SSH protocol version 2");
- sk_write(ssh->s, verstring, strlen(verstring));
- ssh->protocol = ssh2_protocol;
- ssh2_protocol_setup(ssh);
- ssh->version = 2;
- ssh->s_rdpkt = ssh2_rdpkt;
- } else {
- /*
- * Use v1 protocol.
- */
- char verstring[80], vlog[100];
- sprintf(verstring, "SSH-%s-%s",
- (ssh_versioncmp(s->version, "1.5") <= 0 ? s->version : "1.5"),
- sshver);
- sprintf(vlog, "We claim version: %s", verstring);
- logevent(vlog);
- strcat(verstring, "\012");
-
- logevent("Using SSH protocol version 1");
+ {
+ char *verstring;
+
+ if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) {
+ /*
+ * Construct a v2 version string.
+ */
+ verstring = dupprintf("SSH-2.0-%s\015\012", sshver);
+ ssh->version = 2;
+ } else {
+ /*
+ * Construct a v1 version string.
+ */
+ verstring = dupprintf("SSH-%s-%s\012",
+ (ssh_versioncmp(s->version, "1.5") <= 0 ?
+ s->version : "1.5"),
+ sshver);
+ ssh->version = 1;
+ }
+
+ ssh_fix_verstring(verstring);
+
+ if (ssh->version == 2) {
+ /*
+ * Hash our version string and their version string.
+ */
+ SHA_Init(&ssh->exhashbase);
+ sha_string(&ssh->exhashbase, verstring,
+ strcspn(verstring, "\015\012"));
+ sha_string(&ssh->exhashbase, s->vstring,
+ strcspn(s->vstring, "\015\012"));
+
+ /*
+ * Initialise SSHv2 protocol.
+ */
+ ssh->protocol = ssh2_protocol;
+ ssh2_protocol_setup(ssh);
+ ssh->s_rdpkt = ssh2_rdpkt;
+ } else {
+ /*
+ * Initialise SSHv1 protocol.
+ */
+ ssh->protocol = ssh1_protocol;
+ ssh1_protocol_setup(ssh);
+ ssh->s_rdpkt = ssh1_rdpkt;
+ }
+ logeventf(ssh, "We claim version: %.*s",
+ strcspn(verstring, "\015\012"), verstring);
sk_write(ssh->s, verstring, strlen(verstring));
- ssh->protocol = ssh1_protocol;
- ssh1_protocol_setup(ssh);
- ssh->version = 1;
- ssh->s_rdpkt = ssh1_rdpkt;
+ sfree(verstring);
}
+
+ logeventf(ssh, "Using SSH protocol version %d", ssh->version);
+
update_specials_menu(ssh->frontend);
ssh->state = SSH_STATE_BEFORE_SIZE;
ssh->pinger = pinger_new(&ssh->cfg, &ssh_backend, ssh);
crBegin(ssh->do_ssh1_login_crstate);
- random_init();
-
if (!pktin)
crWaitUntil(pktin);
/* Warn about chosen cipher if necessary. */
if (warn)
- askcipher(ssh->frontend, cipher_string, 0);
+ askalg(ssh->frontend, "cipher", cipher_string);
}
switch (s->cipher_type) {
int hostkeylen, siglen;
void *hkey; /* actual host key */
unsigned char exchange_hash[20];
+ int n_preferred_kex;
+ const struct ssh_kex *preferred_kex[KEX_MAX];
int n_preferred_ciphers;
const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
const struct ssh_compress *preferred_comp;
s->csmac_tobe = s->scmac_tobe = NULL;
s->cscomp_tobe = s->sccomp_tobe = NULL;
- random_init();
s->first_kex = 1;
{
int i;
/*
+ * Set up the preferred key exchange. (NULL => warn below here)
+ */
+ s->n_preferred_kex = 0;
+ for (i = 0; i < KEX_MAX; i++) {
+ switch (ssh->cfg.ssh_kexlist[i]) {
+ case KEX_DHGEX:
+ s->preferred_kex[s->n_preferred_kex++] =
+ &ssh_diffiehellman_gex;
+ break;
+ case KEX_DHGROUP14:
+ s->preferred_kex[s->n_preferred_kex++] =
+ &ssh_diffiehellman_group14;
+ break;
+ case KEX_DHGROUP1:
+ s->preferred_kex[s->n_preferred_kex++] =
+ &ssh_diffiehellman_group1;
+ break;
+ case CIPHER_WARN:
+ /* Flag for later. Don't bother if it's the last in
+ * the list. */
+ if (i < KEX_MAX - 1) {
+ s->preferred_kex[s->n_preferred_kex++] = NULL;
+ }
+ break;
+ }
+ }
+ }
+
+ {
+ int i;
+ /*
* Set up the preferred ciphers. (NULL => warn below here)
*/
s->n_preferred_ciphers = 0;
begin_key_exchange:
{
- int i, j, cipherstr_started;
+ int i, j, commalist_started;
/*
* Enable queueing of outgoing auth- or connection-layer
ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
/* List key exchange algorithms. */
ssh2_pkt_addstring_start(s->pktout);
- for (i = 0; i < lenof(kex_algs); i++) {
- if (kex_algs[i] == &ssh_diffiehellman_gex &&
- (ssh->remote_bugs & BUG_SSH2_DH_GEX))
- continue;
- ssh2_pkt_addstring_str(s->pktout, kex_algs[i]->name);
- if (i < lenof(kex_algs) - 1)
+ commalist_started = 0;
+ for (i = 0; i < s->n_preferred_kex; i++) {
+ const struct ssh_kex *k = s->preferred_kex[i];
+ if (!k) continue; /* warning flag */
+ if (commalist_started)
ssh2_pkt_addstring_str(s->pktout, ",");
+ ssh2_pkt_addstring_str(s->pktout, s->preferred_kex[i]->name);
+ commalist_started = 1;
}
/* List server host key algorithms. */
ssh2_pkt_addstring_start(s->pktout);
}
/* List client->server encryption algorithms. */
ssh2_pkt_addstring_start(s->pktout);
- cipherstr_started = 0;
+ commalist_started = 0;
for (i = 0; i < s->n_preferred_ciphers; i++) {
const struct ssh2_ciphers *c = s->preferred_ciphers[i];
if (!c) continue; /* warning flag */
for (j = 0; j < c->nciphers; j++) {
- if (cipherstr_started)
+ if (commalist_started)
ssh2_pkt_addstring_str(s->pktout, ",");
ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
- cipherstr_started = 1;
+ commalist_started = 1;
}
}
/* List server->client encryption algorithms. */
ssh2_pkt_addstring_start(s->pktout);
- cipherstr_started = 0;
+ commalist_started = 0;
for (i = 0; i < s->n_preferred_ciphers; i++) {
const struct ssh2_ciphers *c = s->preferred_ciphers[i];
if (!c) continue; /* warning flag */
for (j = 0; j < c->nciphers; j++) {
- if (cipherstr_started)
+ if (commalist_started)
ssh2_pkt_addstring_str(s->pktout, ",");
ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
- cipherstr_started = 1;
+ commalist_started = 1;
}
}
/* List client->server MAC algorithms. */
s->sccomp_tobe = NULL;
pktin->savedpos += 16; /* skip garbage cookie */
ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
- for (i = 0; i < lenof(kex_algs); i++) {
- if (kex_algs[i] == &ssh_diffiehellman_gex &&
- (ssh->remote_bugs & BUG_SSH2_DH_GEX))
- continue;
- if (in_commasep_string(kex_algs[i]->name, str, len)) {
- ssh->kex = kex_algs[i];
+ s->warn = 0;
+ for (i = 0; i < s->n_preferred_kex; i++) {
+ const struct ssh_kex *k = s->preferred_kex[i];
+ if (!k) {
+ s->warn = 1;
+ } else if (in_commasep_string(k->name, str, len)) {
+ ssh->kex = k;
+ }
+ if (ssh->kex) {
+ if (s->warn)
+ askalg(ssh->frontend, "key-exchange algorithm",
+ ssh->kex->name);
break;
}
}
+ if (!ssh->kex) {
+ bombout(("Couldn't agree a key exchange algorithm (available: %s)",
+ str ? str : "(null)"));
+ crStop(0);
+ }
ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
for (i = 0; i < lenof(hostkey_algs); i++) {
if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
}
if (s->cscipher_tobe) {
if (s->warn)
- askcipher(ssh->frontend, s->cscipher_tobe->name, 1);
+ askalg(ssh->frontend, "client-to-server cipher",
+ s->cscipher_tobe->name);
break;
}
}
}
if (s->sccipher_tobe) {
if (s->warn)
- askcipher(ssh->frontend, s->sccipher_tobe->name, 2);
+ askalg(ssh->frontend, "server-to-client cipher",
+ s->sccipher_tobe->name);
break;
}
}
* If we're doing Diffie-Hellman group exchange, start by
* requesting a group.
*/
- if (ssh->kex == &ssh_diffiehellman_gex) {
+ if (!ssh->kex->pdata) {
logevent("Doing Diffie-Hellman group exchange");
ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
/*
bombout(("unable to read mp-ints from incoming group packet"));
crStop(0);
}
- ssh->kex_ctx = dh_setup_group(s->p, s->g);
+ ssh->kex_ctx = dh_setup_gex(s->p, s->g);
s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
} else {
- ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP1;
- ssh->kex_ctx = dh_setup_group1();
+ ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP;
+ ssh->kex_ctx = dh_setup_group(ssh->kex);
s->kex_init_value = SSH2_MSG_KEXDH_INIT;
s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
+ logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
+ ssh->kex->groupname);
}
logevent("Doing Diffie-Hellman key exchange");
/*
* We've sent client NEWKEYS, so create and initialise
- * client-to-servere session keys.
+ * client-to-server session keys.
*/
if (ssh->cs_cipher_ctx)
ssh->cscipher->free_context(ssh->cs_cipher_ctx);
if (p != NULL)
return p;
+ random_ref();
+
return NULL;
}
sfree(c);
}
freetree234(ssh->channels);
+ ssh->channels = NULL;
}
if (ssh->rportfwds) {
while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
sfree(pf);
freetree234(ssh->rportfwds);
+ ssh->rportfwds = NULL;
}
sfree(ssh->deferred_send_data);
if (ssh->x11auth)
if (ssh->s)
ssh_do_close(ssh);
expire_timer_context(ssh);
- sfree(ssh);
if (ssh->pinger)
pinger_free(ssh->pinger);
+ sfree(ssh);
+
+ random_unref();
}
/*
projects / u / mdw / putty / blobdiff