X-Git-Url: https://git.distorted.org.uk/u/mdw/putty/blobdiff_plain/d38d6a1f7c84cff0c448437676339b3b2ffb091f..51e9d3c00a3471f284e89ec1f59f38ca25f10c5f:/ssh.c diff --git a/ssh.c b/ssh.c index 835a8579..b5f34a52 100644 --- a/ssh.c +++ b/ssh.c @@ -104,8 +104,9 @@ * 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_KEX_MASK 0x000F #define SSH2_PKTCTX_PUBLICKEY 0x0010 #define SSH2_PKTCTX_PASSWORD 0x0020 #define SSH2_PKTCTX_KBDINTER 0x0040 @@ -162,7 +163,7 @@ static const char *const ssh2_disconnect_reasons[] = { #define BUG_CHOKES_ON_RSA 8 #define BUG_SSH2_RSA_PADDING 16 #define BUG_SSH2_DERIVEKEY 32 -#define BUG_SSH2_DH_GEX 64 +#define BUG_SSH2_REKEY 64 #define BUG_SSH2_PK_SESSIONID 128 #define translate(x) if (type == x) return #x @@ -222,8 +223,8 @@ static char *ssh2_pkt_type(int pkt_ctx, int type) 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); @@ -255,18 +256,6 @@ static char *ssh2_pkt_type(int pkt_ctx, int type) #undef translate #undef translatec -#define GET_32BIT(cp) \ - (((unsigned long)(unsigned char)(cp)[0] << 24) | \ - ((unsigned long)(unsigned char)(cp)[1] << 16) | \ - ((unsigned long)(unsigned char)(cp)[2] << 8) | \ - ((unsigned long)(unsigned char)(cp)[3])) - -#define PUT_32BIT(cp, value) { \ - (cp)[0] = (unsigned char)((value) >> 24); \ - (cp)[1] = (unsigned char)((value) >> 16); \ - (cp)[2] = (unsigned char)((value) >> 8); \ - (cp)[3] = (unsigned char)(value); } - /* Enumeration values for fields in SSH-1 packets */ enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM, @@ -341,29 +330,25 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, * * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up * on a local data stream before we throttle the whole SSH - * connection (in SSH1 only). Throttling the whole connection is + * connection (in SSH-1 only). Throttling the whole connection is * pretty drastic so we set this high in the hope it won't * happen very often. * * - SSH_MAX_BACKLOG is the amount of backlog that must build up * on the SSH connection itself before we defensively throttle * _all_ local data streams. This is pretty drastic too (though - * thankfully unlikely in SSH2 since the window mechanism should + * thankfully unlikely in SSH-2 since the window mechanism should * ensure that the server never has any need to throttle its end * of the connection), so we set this high as well. * - * - OUR_V2_WINSIZE is the maximum window size we present on SSH2 + * - OUR_V2_WINSIZE is the maximum window size we present on SSH-2 * channels. */ #define SSH1_BUFFER_LIMIT 32768 #define SSH_MAX_BACKLOG 32768 #define OUR_V2_WINSIZE 16384 - -const static struct ssh_kex *kex_algs[] = { - &ssh_diffiehellman_gex, - &ssh_diffiehellman -}; +#define OUR_V2_MAXPKT 0x4000UL const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss }; @@ -439,8 +424,10 @@ struct ssh_channel { Ssh ssh; /* pointer back to main context */ unsigned remoteid, localid; int type; + /* True if we opened this channel but server hasn't confirmed. */ + int halfopen; /* - * In SSH1, this value contains four bits: + * In SSH-1, this value contains four bits: * * 1 We have sent SSH1_MSG_CHANNEL_CLOSE. * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION. @@ -476,11 +463,11 @@ struct ssh_channel { }; /* - * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH - * 2 use this structure in different ways, reflecting SSH 2's + * 2-3-4 tree storing remote->local port forwardings. SSH-1 and SSH-2 + * use this structure in different ways, reflecting SSH-2's * altogether saner approach to port forwarding. * - * In SSH 1, you arrange a remote forwarding by sending the server + * In SSH-1, you arrange a remote forwarding by sending the server * the remote port number, and the local destination host:port. * When a connection comes in, the server sends you back that * host:port pair, and you connect to it. This is a ready-made @@ -492,32 +479,58 @@ struct ssh_channel { * host:port pairs we _are_ trying to forward to, and reject a * connection request from the server if it's not in the list. * - * In SSH 2, each side of the connection minds its own business and + * In SSH-2, each side of the connection minds its own business and * doesn't send unnecessary information to the other. You arrange a * remote forwarding by sending the server just the remote port * number. When a connection comes in, the server tells you which * of its ports was connected to; and _you_ have to remember what * local host:port pair went with that port number. * - * Hence: in SSH 1 this structure stores host:port pairs we intend - * to allow connections to, and is indexed by those host:port - * pairs. In SSH 2 it stores a mapping from source port to - * destination host:port pair, and is indexed by source port. + * Hence, in SSH-1 this structure is indexed by destination + * host:port pair, whereas in SSH-2 it is indexed by source port. */ +struct ssh_portfwd; /* forward declaration */ + struct ssh_rportfwd { unsigned sport, dport; char dhost[256]; + char *sportdesc; + struct ssh_portfwd *pfrec; +}; +#define free_rportfwd(pf) ( \ + ((pf) ? (sfree((pf)->sportdesc)) : (void)0 ), sfree(pf) ) + +/* + * Separately to the rportfwd tree (which is for looking up port + * open requests from the server), a tree of _these_ structures is + * used to keep track of all the currently open port forwardings, + * so that we can reconfigure in mid-session if the user requests + * it. + */ +struct ssh_portfwd { + enum { DESTROY, KEEP, CREATE } status; + int type; + unsigned sport, dport; + char *saddr, *daddr; + char *sserv, *dserv; + struct ssh_rportfwd *remote; + int addressfamily; + void *local; }; +#define free_portfwd(pf) ( \ + ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \ + sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) ) struct Packet { long length; + long forcepad; /* Force padding to at least this length */ int type; unsigned long sequence; unsigned char *data; unsigned char *body; long savedpos; long maxlen; - long encrypted_len; /* for SSH2 total-size counting */ + long encrypted_len; /* for SSH-2 total-size counting */ /* * State associated with packet logging @@ -527,9 +540,9 @@ struct Packet { struct logblank_t *blanks; }; -static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, +static void ssh1_protocol(Ssh ssh, void *vin, int inlen, struct Packet *pktin); -static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, +static void ssh2_protocol(Ssh ssh, void *vin, int inlen, struct Packet *pktin); static void ssh1_protocol_setup(Ssh ssh); static void ssh2_protocol_setup(Ssh ssh); @@ -540,12 +553,12 @@ static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len); static void ssh_throttle_all(Ssh ssh, int enable, int bufsize); static void ssh2_set_window(struct ssh_channel *c, unsigned newwin); static int ssh_sendbuffer(void *handle); -static void ssh_do_close(Ssh ssh); +static int ssh_do_close(Ssh ssh, int notify_exit); static unsigned long ssh_pkt_getuint32(struct Packet *pkt); static int ssh2_pkt_getbool(struct Packet *pkt); static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length); static void ssh2_timer(void *ctx, long now); -static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, +static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, struct Packet *pktin); struct rdpkt1_state_tag { @@ -566,6 +579,15 @@ struct rdpkt2_state_tag { }; typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin); +typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx); + +struct queued_handler; +struct queued_handler { + int msg1, msg2; + chandler_fn_t handler; + void *ctx; + struct queued_handler *next; +}; struct ssh_tag { const struct plug_function_table *fn; @@ -612,8 +634,9 @@ struct ssh_tag { tree234 *channels; /* indexed by local id */ struct ssh_channel *mainchan; /* primary session channel */ int exitcode; + int close_expected; - tree234 *rportfwds; + tree234 *rportfwds, *portfwds; enum { SSH_STATE_PREPACKET, @@ -647,7 +670,6 @@ struct ssh_tag { int userpass_input_bufpos; int userpass_input_echo; - char *portfwd_strptr; int pkt_ctx; void *x11auth; @@ -657,7 +679,7 @@ struct ssh_tag { int overall_bufsize; int throttled_all; int v1_stdout_throttling; - int v2_outgoing_sequence; + unsigned long v2_outgoing_sequence; int ssh1_rdpkt_crstate; int ssh2_rdpkt_crstate; @@ -676,10 +698,10 @@ struct ssh_tag { struct rdpkt1_state_tag rdpkt1_state; struct rdpkt2_state_tag rdpkt2_state; - /* ssh1 and ssh2 use this for different things, but both use it */ + /* SSH-1 and SSH-2 use this for different things, but both use it */ int protocol_initial_phase_done; - void (*protocol) (Ssh ssh, unsigned char *in, int inlen, + void (*protocol) (Ssh ssh, void *vin, int inlen, struct Packet *pkt); struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen); @@ -692,10 +714,23 @@ struct ssh_tag { Config cfg; /* - * Used to transfer data back from async agent callbacks. + * Used to transfer data back from async callbacks. */ void *agent_response; int agent_response_len; + int user_response; + + /* + * The SSH connection can be set as `frozen', meaning we are + * not currently accepting incoming data from the network. This + * is slightly more serious than setting the _socket_ as + * frozen, because we may already have had data passed to us + * from the network which we need to delay processing until + * after the freeze is lifted, so we also need a bufchain to + * store that data. + */ + int frozen; + bufchain queued_incoming_data; /* * Dispatch table for packet types that we may have to deal @@ -704,6 +739,12 @@ struct ssh_tag { handler_fn_t packet_dispatch[256]; /* + * Queues of one-off handler functions for success/failure + * indications from a request. + */ + struct queued_handler *qhead, *qtail; + + /* * This module deals with sending keepalives. */ Pinger pinger; @@ -713,13 +754,12 @@ struct ssh_tag { * size-based rekeys. */ unsigned long incoming_data_size, outgoing_data_size, deferred_data_size; + unsigned long max_data_size; int kex_in_progress; - long next_rekey; + long next_rekey, last_rekey; + char *deferred_rekey_reason; /* points to STATIC string; don't free */ }; -#define MAX_DATA_BEFORE_REKEY (0x40000000UL) -#define REKEY_TIMEOUT (3600 * TICKSPERSEC) - #define logevent(s) logevent(ssh->frontend, s) /* logevent, only printf-formatted. */ @@ -738,7 +778,7 @@ static void logeventf(Ssh ssh, const char *fmt, ...) #define bombout(msg) \ do { \ char *text = dupprintf msg; \ - ssh_do_close(ssh); \ + ssh_do_close(ssh, FALSE); \ logevent(text); \ connection_fatal(ssh->frontend, "%s", text); \ sfree(text); \ @@ -810,6 +850,51 @@ static int ssh_rportcmp_ssh2(void *av, void *bv) return 0; } +/* + * Special form of strcmp which can cope with NULL inputs. NULL is + * defined to sort before even the empty string. + */ +static int nullstrcmp(const char *a, const char *b) +{ + if (a == NULL && b == NULL) + return 0; + if (a == NULL) + return -1; + if (b == NULL) + return +1; + return strcmp(a, b); +} + +static int ssh_portcmp(void *av, void *bv) +{ + struct ssh_portfwd *a = (struct ssh_portfwd *) av; + struct ssh_portfwd *b = (struct ssh_portfwd *) bv; + int i; + if (a->type > b->type) + return +1; + if (a->type < b->type) + return -1; + if (a->addressfamily > b->addressfamily) + return +1; + if (a->addressfamily < b->addressfamily) + return -1; + if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0) + return i < 0 ? -1 : +1; + if (a->sport > b->sport) + return +1; + if (a->sport < b->sport) + return -1; + if (a->type != 'D') { + if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0) + return i < 0 ? -1 : +1; + if (a->dport > b->dport) + return +1; + if (a->dport < b->dport) + return -1; + } + return 0; +} + static int alloc_channel_id(Ssh ssh) { const unsigned CHANNEL_NUMBER_OFFSET = 256; @@ -1461,7 +1546,7 @@ static void sha_uint32(SHA_State * s, unsigned i) } /* - * SSH2 packet construction functions. + * SSH-2 packet construction functions. */ static void ssh2_pkt_ensure(struct Packet *pkt, int length) { @@ -1491,6 +1576,7 @@ static struct Packet *ssh2_pkt_init(int pkt_type) { struct Packet *pkt = ssh_new_packet(); pkt->length = 5; + pkt->forcepad = 0; ssh2_pkt_addbyte(pkt, (unsigned char) pkt_type); return pkt; } @@ -1552,7 +1638,7 @@ static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b) } /* - * Construct an SSH2 final-form packet: compress it, encrypt it, + * Construct an SSH-2 final-form packet: compress it, encrypt it, * put the MAC on it. Final packet, ready to be sent, is stored in * pkt->data. Total length is returned. */ @@ -1587,12 +1673,17 @@ static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt) /* * Add padding. At least four bytes, and must also bring total * length (minus MAC) up to a multiple of the block size. + * If pkt->forcepad is set, make sure the packet is at least that size + * after padding. */ cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */ cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */ padding = 4; + if (pkt->length + padding < pkt->forcepad) + padding = pkt->forcepad - pkt->length; padding += (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk; + assert(padding <= 255); maclen = ssh->csmac ? ssh->csmac->len : 0; ssh2_pkt_ensure(pkt, pkt->length + padding + maclen); pkt->data[4] = padding; @@ -1645,7 +1736,7 @@ static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt) */ /* - * Send an SSH2 packet immediately, without queuing or deferring. + * Send an SSH-2 packet immediately, without queuing or deferring. */ static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt) { @@ -1658,15 +1749,15 @@ static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt) ssh->outgoing_data_size += pkt->encrypted_len; if (!ssh->kex_in_progress && - ssh->outgoing_data_size > MAX_DATA_BEFORE_REKEY) - do_ssh2_transport(ssh, "Initiating key re-exchange " - "(too much data sent)", -1, NULL); + ssh->max_data_size != 0 && + ssh->outgoing_data_size > ssh->max_data_size) + do_ssh2_transport(ssh, "too much data sent", -1, NULL); ssh_free_packet(pkt); } /* - * Defer an SSH2 packet. + * Defer an SSH-2 packet. */ static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt) { @@ -1684,7 +1775,7 @@ static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt) } /* - * Queue an SSH2 packet. + * Queue an SSH-2 packet. */ static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt) { @@ -1710,6 +1801,7 @@ static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt) ssh2_pkt_send_noqueue(ssh, pkt); } +#if 0 /* disused */ /* * Either queue or defer a packet, depending on whether queueing is * set. @@ -1721,10 +1813,11 @@ static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt) else ssh2_pkt_defer_noqueue(ssh, pkt); } +#endif /* * Send the whole deferred data block constructed by - * ssh2_pkt_defer() or SSH1's defer_packet(). + * ssh2_pkt_defer() or SSH-1's defer_packet(). * * The expected use of the defer mechanism is that you call * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If @@ -1748,14 +1841,14 @@ static void ssh_pkt_defersend(Ssh ssh) ssh->outgoing_data_size += ssh->deferred_data_size; if (!ssh->kex_in_progress && - ssh->outgoing_data_size > MAX_DATA_BEFORE_REKEY) - do_ssh2_transport(ssh, "Initiating key re-exchange " - "(too much data sent)", -1, NULL); + ssh->max_data_size != 0 && + ssh->outgoing_data_size > ssh->max_data_size) + do_ssh2_transport(ssh, "too much data sent", -1, NULL); ssh->deferred_data_size = 0; } /* - * Send all queued SSH2 packets. We send them by means of + * Send all queued SSH-2 packets. We send them by means of * ssh2_pkt_defer_noqueue(), in case they included a pair of * packets that needed to be lumped together. */ @@ -1796,7 +1889,7 @@ static void sha_mpint(SHA_State * s, Bignum b) } /* - * Packet decode functions for both SSH1 and SSH2. + * Packet decode functions for both SSH-1 and SSH-2. */ static unsigned long ssh_pkt_getuint32(struct Packet *pkt) { @@ -1887,7 +1980,7 @@ static Bignum ssh2_pkt_getmp(struct Packet *pkt) } /* - * Helper function to add an SSH2 signature blob to a packet. + * Helper function to add an SSH-2 signature blob to a packet. * Expects to be shown the public key blob as well as the signature * blob. Normally works just like ssh2_pkt_addstring, but will * fiddle with the signature packet if necessary for @@ -1983,7 +2076,7 @@ static void ssh_detect_bugs(Ssh ssh, char *vstring) * sniffing. */ ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE; - logevent("We believe remote version has SSH1 ignore bug"); + logevent("We believe remote version has SSH-1 ignore bug"); } if (ssh->cfg.sshbug_plainpw1 == FORCE_ON || @@ -1995,7 +2088,7 @@ static void ssh_detect_bugs(Ssh ssh, char *vstring) * the password. */ ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD; - logevent("We believe remote version needs a plain SSH1 password"); + logevent("We believe remote version needs a plain SSH-1 password"); } if (ssh->cfg.sshbug_rsa1 == FORCE_ON || @@ -2007,7 +2100,7 @@ static void ssh_detect_bugs(Ssh ssh, char *vstring) * an AUTH_RSA message. */ ssh->remote_bugs |= BUG_CHOKES_ON_RSA; - logevent("We believe remote version can't handle RSA authentication"); + logevent("We believe remote version can't handle SSH-1 RSA authentication"); } if (ssh->cfg.sshbug_hmac2 == FORCE_ON || @@ -2020,7 +2113,7 @@ static void ssh_detect_bugs(Ssh ssh, char *vstring) * These versions have the HMAC bug. */ ssh->remote_bugs |= BUG_SSH2_HMAC; - logevent("We believe remote version has SSH2 HMAC bug"); + logevent("We believe remote version has SSH-2 HMAC bug"); } if (ssh->cfg.sshbug_derivekey2 == FORCE_ON || @@ -2033,7 +2126,7 @@ static void ssh_detect_bugs(Ssh ssh, char *vstring) * generate the keys). */ ssh->remote_bugs |= BUG_SSH2_DERIVEKEY; - logevent("We believe remote version has SSH2 key-derivation bug"); + logevent("We believe remote version has SSH-2 key-derivation bug"); } if (ssh->cfg.sshbug_rsapad2 == FORCE_ON || @@ -2041,29 +2134,34 @@ static void ssh_detect_bugs(Ssh ssh, char *vstring) (wc_match("OpenSSH_2.[5-9]*", imp) || wc_match("OpenSSH_3.[0-2]*", imp)))) { /* - * These versions have the SSH2 RSA padding bug. + * These versions have the SSH-2 RSA padding bug. */ ssh->remote_bugs |= BUG_SSH2_RSA_PADDING; - logevent("We believe remote version has SSH2 RSA padding bug"); + logevent("We believe remote version has SSH-2 RSA padding bug"); } if (ssh->cfg.sshbug_pksessid2 == FORCE_ON || (ssh->cfg.sshbug_pksessid2 == AUTO && wc_match("OpenSSH_2.[0-2]*", imp))) { /* - * These versions have the SSH2 session-ID bug in + * These versions have the SSH-2 session-ID bug in * public-key authentication. */ ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID; - logevent("We believe remote version has SSH2 public-key-session-ID bug"); + logevent("We believe remote version has SSH-2 public-key-session-ID bug"); } - if (ssh->cfg.sshbug_dhgex2 == FORCE_ON) { + if (ssh->cfg.sshbug_rekey2 == FORCE_ON || + (ssh->cfg.sshbug_rekey2 == AUTO && + (wc_match("OpenSSH_2.[0-4]*", imp) || + wc_match("OpenSSH_2.5.[0-3]*", imp) || + wc_match("Sun_SSH_1.0", imp) || + wc_match("Sun_SSH_1.0.1", imp)))) { /* - * User specified the SSH2 DH GEX bug. + * These versions have the SSH-2 rekey bug. */ - ssh->remote_bugs |= BUG_SSH2_DH_GEX; - logevent("We believe remote version has SSH2 DH group exchange bug"); + ssh->remote_bugs |= BUG_SSH2_REKEY; + logevent("We believe remote version has SSH-2 rekey bug"); } } @@ -2149,14 +2247,8 @@ static int do_ssh_init(Ssh ssh, unsigned char c) ssh->rdpkt2_state.incoming_sequence = 0; s->vstring[s->vslen] = 0; - s->vstring[strcspn(s->vstring, "\r\n")] = '\0';/* remove EOL chars */ - { - char *vlog; - vlog = snewn(20 + s->vslen, char); - sprintf(vlog, "Server version: %s", s->vstring); - logevent(vlog); - sfree(vlog); - } + s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */ + logeventf(ssh, "Server version: %s", s->vstring); ssh_detect_bugs(ssh, s->vstring); /* @@ -2184,13 +2276,13 @@ static int do_ssh_init(Ssh ssh, unsigned char c) /* * Construct a v2 version string. */ - verstring = dupprintf("SSH-2.0-%s\n", sshver); + verstring = dupprintf("SSH-2.0-%s\015\012", sshver); ssh->version = 2; } else { /* * Construct a v1 version string. */ - verstring = dupprintf("SSH-%s-%s\n", + verstring = dupprintf("SSH-%s-%s\012", (ssh_versioncmp(s->version, "1.5") <= 0 ? s->version : "1.5"), sshver); @@ -2204,25 +2296,27 @@ static int do_ssh_init(Ssh ssh, unsigned char c) * Hash our version string and their version string. */ SHA_Init(&ssh->exhashbase); - sha_string(&ssh->exhashbase, verstring, strlen(verstring)-1); - sha_string(&ssh->exhashbase, s->vstring, strcspn(s->vstring, "\r\n")); + sha_string(&ssh->exhashbase, verstring, + strcspn(verstring, "\015\012")); + sha_string(&ssh->exhashbase, s->vstring, + strcspn(s->vstring, "\015\012")); /* - * Initialise SSHv2 protocol. + * Initialise SSH-2 protocol. */ ssh->protocol = ssh2_protocol; ssh2_protocol_setup(ssh); ssh->s_rdpkt = ssh2_rdpkt; } else { /* - * Initialise SSHv1 protocol. + * Initialise SSH-1 protocol. */ ssh->protocol = ssh1_protocol; ssh1_protocol_setup(ssh); ssh->s_rdpkt = ssh1_rdpkt; } logeventf(ssh, "We claim version: %.*s", - strlen(verstring)-1, verstring); + strcspn(verstring, "\015\012"), verstring); sk_write(ssh->s, verstring, strlen(verstring)); sfree(verstring); } @@ -2238,6 +2332,50 @@ static int do_ssh_init(Ssh ssh, unsigned char c) crFinish(0); } +static void ssh_process_incoming_data(Ssh ssh, + unsigned char **data, int *datalen) +{ + struct Packet *pktin = ssh->s_rdpkt(ssh, data, datalen); + if (pktin) { + ssh->protocol(ssh, NULL, 0, pktin); + ssh_free_packet(pktin); + } +} + +static void ssh_queue_incoming_data(Ssh ssh, + unsigned char **data, int *datalen) +{ + bufchain_add(&ssh->queued_incoming_data, *data, *datalen); + *data += *datalen; + *datalen = 0; +} + +static void ssh_process_queued_incoming_data(Ssh ssh) +{ + void *vdata; + unsigned char *data; + int len, origlen; + + while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) { + bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len); + data = vdata; + origlen = len; + + while (!ssh->frozen && len > 0) + ssh_process_incoming_data(ssh, &data, &len); + + if (origlen > len) + bufchain_consume(&ssh->queued_incoming_data, origlen - len); + } +} + +static void ssh_set_frozen(Ssh ssh, int frozen) +{ + if (ssh->s) + sk_set_frozen(ssh->s, frozen); + ssh->frozen = frozen; +} + static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen) { crBegin(ssh->ssh_gotdata_crstate); @@ -2267,13 +2405,19 @@ static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen) */ if (datalen == 0) crReturnV; + + /* + * Process queued data if there is any. + */ + ssh_process_queued_incoming_data(ssh); + while (1) { while (datalen > 0) { - struct Packet *pktin = ssh->s_rdpkt(ssh, &data, &datalen); - if (pktin) { - ssh->protocol(ssh, NULL, 0, pktin); - ssh_free_packet(pktin); - } + if (ssh->frozen) + ssh_queue_incoming_data(ssh, &data, &datalen); + + ssh_process_incoming_data(ssh, &data, &datalen); + if (ssh->state == SSH_STATE_CLOSED) return; } @@ -2282,23 +2426,27 @@ static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen) crFinishV; } -static void ssh_do_close(Ssh ssh) +static int ssh_do_close(Ssh ssh, int notify_exit) { - int i; + int ret = 0; struct ssh_channel *c; ssh->state = SSH_STATE_CLOSED; + expire_timer_context(ssh); if (ssh->s) { sk_close(ssh->s); ssh->s = NULL; - notify_remote_exit(ssh->frontend); + if (notify_exit) + notify_remote_exit(ssh->frontend); + else + ret = 1; } /* - * Now we must shut down any port and X forwardings going + * Now we must shut down any port- and X-forwarded channels going * through this connection. */ if (ssh->channels) { - for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) { + while (NULL != (c = index234(ssh->channels, 0))) { switch (c->type) { case CHAN_X11: x11_close(c->u.x11.s); @@ -2307,25 +2455,66 @@ static void ssh_do_close(Ssh ssh) pfd_close(c->u.pfd.s); break; } - del234(ssh->channels, c); + del234(ssh->channels, c); /* moving next one to index 0 */ if (ssh->version == 2) bufchain_clear(&c->v.v2.outbuffer); sfree(c); } } + /* + * Go through port-forwardings, and close any associated + * listening sockets. + */ + if (ssh->portfwds) { + struct ssh_portfwd *pf; + while (NULL != (pf = index234(ssh->portfwds, 0))) { + /* Dispose of any listening socket. */ + if (pf->local) + pfd_terminate(pf->local); + del234(ssh->portfwds, pf); /* moving next one to index 0 */ + free_portfwd(pf); + } + } + + return ret; +} + +static void ssh_log(Plug plug, int type, SockAddr addr, int port, + const char *error_msg, int error_code) +{ + Ssh ssh = (Ssh) plug; + char addrbuf[256], *msg; + + sk_getaddr(addr, addrbuf, lenof(addrbuf)); + + if (type == 0) + msg = dupprintf("Connecting to %s port %d", addrbuf, port); + else + msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg); + + logevent(msg); + sfree(msg); } static int ssh_closing(Plug plug, const char *error_msg, int error_code, int calling_back) { Ssh ssh = (Ssh) plug; - ssh_do_close(ssh); + int need_notify = ssh_do_close(ssh, FALSE); + + if (!error_msg && !ssh->close_expected) { + error_msg = "Server unexpectedly closed network connection"; + } + + if (need_notify) + notify_remote_exit(ssh->frontend); + if (error_msg) { /* A socket error has occurred. */ logevent(error_msg); connection_fatal(ssh->frontend, "%s", error_msg); } else { - /* Otherwise, the remote side closed the connection normally. */ + logevent("Server closed network connection"); } return 0; } @@ -2335,7 +2524,7 @@ static int ssh_receive(Plug plug, int urgent, char *data, int len) Ssh ssh = (Ssh) plug; ssh_gotdata(ssh, (unsigned char *)data, len); if (ssh->state == SSH_STATE_CLOSED) { - ssh_do_close(ssh); + ssh_do_close(ssh, TRUE); return 0; } return 1; @@ -2362,6 +2551,7 @@ static const char *connect_to_host(Ssh ssh, char *host, int port, char **realhost, int nodelay, int keepalive) { static const struct plug_function_table fn_table = { + ssh_log, ssh_closing, ssh_receive, ssh_sent, @@ -2383,8 +2573,11 @@ static const char *connect_to_host(Ssh ssh, char *host, int port, /* * Try to find host. */ - logeventf(ssh, "Looking up host \"%s\"", host); - addr = name_lookup(host, port, realhost, &ssh->cfg); + logeventf(ssh, "Looking up host \"%s\"%s", host, + (ssh->cfg.addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" : + (ssh->cfg.addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : ""))); + addr = name_lookup(host, port, realhost, &ssh->cfg, + ssh->cfg.addressfamily); if ((err = sk_addr_error(addr)) != NULL) { sk_addr_free(addr); return err; @@ -2393,11 +2586,6 @@ static const char *connect_to_host(Ssh ssh, char *host, int port, /* * Open socket. */ - { - char addrbuf[100]; - sk_getaddr(addr, addrbuf, 100); - logeventf(ssh, "Connecting to %s port %d", addrbuf, port); - } ssh->fn = &fn_table; ssh->s = new_connection(addr, *realhost, port, 0, 1, nodelay, keepalive, (Plug) ssh, &ssh->cfg); @@ -2419,9 +2607,9 @@ static void ssh1_throttle(Ssh ssh, int adjust) ssh->v1_throttle_count += adjust; assert(ssh->v1_throttle_count >= 0); if (ssh->v1_throttle_count && !old_count) { - sk_set_frozen(ssh->s, 1); + ssh_set_frozen(ssh, 1); } else if (!ssh->v1_throttle_count && old_count) { - sk_set_frozen(ssh->s, 0); + ssh_set_frozen(ssh, 0); } } @@ -2462,7 +2650,7 @@ static void ssh_throttle_all(Ssh ssh, int enable, int bufsize) /* * Username and password input, abstracted off into routines - * reusable in several places - even between SSH1 and SSH2. + * reusable in several places - even between SSH-1 and SSH-2. */ /* Set up a username or password input loop on a given buffer. */ @@ -2545,6 +2733,24 @@ static void ssh_agent_callback(void *sshv, void *reply, int replylen) do_ssh2_authconn(ssh, NULL, -1, NULL); } +static void ssh_dialog_callback(void *sshv, int ret) +{ + Ssh ssh = (Ssh) sshv; + + ssh->user_response = ret; + + if (ssh->version == 1) + do_ssh1_login(ssh, NULL, -1, NULL); + else + do_ssh2_transport(ssh, NULL, -1, NULL); + + /* + * This may have unfrozen the SSH connection, so do a + * queued-data run. + */ + ssh_process_queued_incoming_data(ssh); +} + static void ssh_agentf_callback(void *cv, void *reply, int replylen) { struct ssh_channel *c = (struct ssh_channel *)cv; @@ -2606,6 +2812,7 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, Bignum challenge; char *commentp; int commentlen; + int dlgret; }; crState(do_ssh1_login_state); @@ -2623,14 +2830,14 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, ptr = ssh_pkt_getdata(pktin, 8); if (!ptr) { - bombout(("SSH1 public key packet stopped before random cookie")); + bombout(("SSH-1 public key packet stopped before random cookie")); crStop(0); } memcpy(cookie, ptr, 8); if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) || !ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) { - bombout(("Failed to read SSH1 public keys from public key packet")); + bombout(("Failed to read SSH-1 public keys from public key packet")); crStop(0); } @@ -2669,7 +2876,7 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, */ if (hostkey.bits > hostkey.bytes * 8 || servkey.bits > servkey.bytes * 8) { - bombout(("SSH1 public keys were badly formatted")); + bombout(("SSH-1 public keys were badly formatted")); crStop(0); } @@ -2693,10 +2900,31 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, fatalbox("Out of memory"); rsastr_fmt(keystr, &hostkey); rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey); - verify_ssh_host_key(ssh->frontend, - ssh->savedhost, ssh->savedport, "rsa", keystr, - fingerprint); + + 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->close_expected = TRUE; + ssh_closing((Plug)ssh, NULL, 0, 0); + crStop(0); + } } for (i = 0; i < 32; i++) { @@ -2715,7 +2943,7 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey); } if (!ret) { - bombout(("SSH1 public key encryptions failed due to bad formatting")); + bombout(("SSH-1 public key encryptions failed due to bad formatting")); crStop(0); } @@ -2732,7 +2960,7 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, warn = 1; } else if (next_cipher == CIPHER_AES) { /* XXX Probably don't need to mention this. */ - logevent("AES not supported in SSH1, skipping"); + logevent("AES not supported in SSH-1, skipping"); } else { switch (next_cipher) { case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES; @@ -2748,7 +2976,7 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, } if (!cipher_chosen) { if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0) - bombout(("Server violates SSH 1 protocol by not " + bombout(("Server violates SSH-1 protocol by not " "supporting 3DES encryption")); else /* shouldn't happen */ @@ -2757,8 +2985,28 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, } /* Warn about chosen cipher if necessary. */ - if (warn) - askcipher(ssh->frontend, cipher_string, 0); + if (warn) { + ssh_set_frozen(ssh, 1); + s->dlgret = askalg(ssh->frontend, "cipher", cipher_string, + ssh_dialog_callback, ssh); + if (s->dlgret < 0) { + do { + crReturn(0); + if (pktin) { + bombout(("Unexpected data from server while waiting" + " for user response")); + crStop(0); + } + } while (pktin || inlen > 0); + s->dlgret = ssh->user_response; + } + ssh_set_frozen(ssh, 0); + if (s->dlgret == 0) { + ssh->close_expected = TRUE; + ssh_closing((Plug)ssh, NULL, 0, 0); + crStop(0); + } + } } switch (s->cipher_type) { @@ -2830,6 +3078,7 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, * Terminate. */ logevent("No username provided. Abandoning session."); + ssh->close_expected = TRUE; ssh_closing((Plug)ssh, NULL, 0, 0); crStop(1); } @@ -2917,17 +3166,9 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, s->p = s->response + 5; s->nkeys = GET_32BIT(s->p); s->p += 4; - { - char buf[64]; - sprintf(buf, "Pageant has %d SSH1 keys", s->nkeys); - logevent(buf); - } + logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys); for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) { - { - char buf[64]; - sprintf(buf, "Trying Pageant key #%d", s->keyi); - logevent(buf); - } + logeventf(ssh, "Trying Pageant key #%d", s->keyi); if (s->publickey_blob && !memcmp(s->p, s->publickey_blob, s->publickey_bloblen)) { @@ -3085,6 +3326,7 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, bombout(("TIS challenge packet was badly formed")); crStop(0); } + c_write_str(ssh, "Using TIS authentication.\r\n"); logevent("Received TIS challenge"); if (challengelen > sizeof(s->prompt) - 1) challengelen = sizeof(s->prompt) - 1;/* prevent overrun */ @@ -3118,6 +3360,7 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, bombout(("CryptoCard challenge packet was badly formed")); crStop(0); } + c_write_str(ssh, "Using CryptoCard authentication.\r\n"); logevent("Received CryptoCard challenge"); if (challengelen > sizeof(s->prompt) - 1) challengelen = sizeof(s->prompt) - 1;/* prevent overrun */ @@ -3136,18 +3379,18 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) { char *comment = NULL; int type; - char msgbuf[256]; if (flags & FLAG_VERBOSE) c_write_str(ssh, "Trying public key authentication.\r\n"); logeventf(ssh, "Trying public key \"%s\"", filename_to_str(&ssh->cfg.keyfile)); type = key_type(&ssh->cfg.keyfile); if (type != SSH_KEYTYPE_SSH1) { - sprintf(msgbuf, "Key is of wrong type (%s)", - key_type_to_str(type)); - logevent(msgbuf); - c_write_str(ssh, msgbuf); + char *msg = dupprintf("Key is of wrong type (%s)", + key_type_to_str(type)); + logevent(msg); + c_write_str(ssh, msg); c_write_str(ssh, "\r\n"); + sfree(msg); s->tried_publickey = 1; continue; } @@ -3178,6 +3421,7 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, PKT_END); logevent("Unable to authenticate"); connection_fatal(ssh->frontend, "Unable to authenticate"); + ssh->close_expected = TRUE; ssh_closing((Plug)ssh, NULL, 0, 0); crStop(1); } @@ -3429,20 +3673,18 @@ void sshfwd_close(struct ssh_channel *c) { Ssh ssh = c->ssh; - if (ssh->state != SSH_STATE_SESSION) { - assert(ssh->state == SSH_STATE_CLOSED); + if (ssh->state == SSH_STATE_CLOSED) return; - } if (c && !c->closes) { /* - * If the channel's remoteid is -1, we have sent + * If halfopen is true, we have sent * CHANNEL_OPEN for this channel, but it hasn't even been * acknowledged by the server. So we must set a close flag * on it now, and then when the server acks the channel * open, we can close it then. */ - if (((int)c->remoteid) != -1) { + if (!c->halfopen) { if (ssh->version == 1) { send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid, PKT_END); @@ -3469,10 +3711,8 @@ int sshfwd_write(struct ssh_channel *c, char *buf, int len) { Ssh ssh = c->ssh; - if (ssh->state != SSH_STATE_SESSION) { - assert(ssh->state == SSH_STATE_CLOSED); + if (ssh->state == SSH_STATE_CLOSED) return 0; - } if (ssh->version == 1) { send_packet(ssh, SSH1_MSG_CHANNEL_DATA, @@ -3481,7 +3721,7 @@ int sshfwd_write(struct ssh_channel *c, char *buf, int len) PKT_INT, len, PKT_DATA, buf, len, PKTT_OTHER, PKT_END); /* - * In SSH1 we can return 0 here - implying that forwarded + * In SSH-1 we can return 0 here - implying that forwarded * connections are never individually throttled - because * the only circumstance that can cause throttling will be * the whole SSH connection backing up, in which case @@ -3498,10 +3738,8 @@ void sshfwd_unthrottle(struct ssh_channel *c, int bufsize) { Ssh ssh = c->ssh; - if (ssh->state != SSH_STATE_SESSION) { - assert(ssh->state == SSH_STATE_CLOSED); + if (ssh->state == SSH_STATE_CLOSED) return; - } if (ssh->version == 1) { if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) { @@ -3513,6 +3751,416 @@ void sshfwd_unthrottle(struct ssh_channel *c, int bufsize) } } +static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin) +{ + struct queued_handler *qh = ssh->qhead; + + assert(qh != NULL); + + assert(pktin->type == qh->msg1 || pktin->type == qh->msg2); + + if (qh->msg1 > 0) { + assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler); + ssh->packet_dispatch[qh->msg1] = NULL; + } + if (qh->msg2 > 0) { + assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler); + ssh->packet_dispatch[qh->msg2] = NULL; + } + + if (qh->next) { + ssh->qhead = qh->next; + + if (ssh->qhead->msg1 > 0) { + assert(ssh->packet_dispatch[ssh->qhead->msg1] == NULL); + ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler; + } + if (ssh->qhead->msg2 > 0) { + assert(ssh->packet_dispatch[ssh->qhead->msg2] == NULL); + ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler; + } + } else { + ssh->qhead = ssh->qtail = NULL; + ssh->packet_dispatch[pktin->type] = NULL; + } + + qh->handler(ssh, pktin, qh->ctx); + + sfree(qh); +} + +static void ssh_queue_handler(Ssh ssh, int msg1, int msg2, + chandler_fn_t handler, void *ctx) +{ + struct queued_handler *qh; + + qh = snew(struct queued_handler); + qh->msg1 = msg1; + qh->msg2 = msg2; + qh->handler = handler; + qh->ctx = ctx; + qh->next = NULL; + + if (ssh->qtail == NULL) { + ssh->qhead = qh; + + if (qh->msg1 > 0) { + assert(ssh->packet_dispatch[qh->msg1] == NULL); + ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler; + } + if (qh->msg2 > 0) { + assert(ssh->packet_dispatch[qh->msg2] == NULL); + ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler; + } + } else { + ssh->qtail->next = qh; + } + ssh->qtail = qh; +} + +static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx) +{ + struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx; + + if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS : + SSH2_MSG_REQUEST_SUCCESS)) { + logeventf(ssh, "Remote port forwarding from %s enabled", + pf->sportdesc); + } else { + logeventf(ssh, "Remote port forwarding from %s refused", + pf->sportdesc); + + rpf = del234(ssh->rportfwds, pf); + assert(rpf == pf); + free_rportfwd(pf); + } +} + +static void ssh_setup_portfwd(Ssh ssh, const Config *cfg) +{ + const char *portfwd_strptr = cfg->portfwd; + struct ssh_portfwd *epf; + int i; + + if (!ssh->portfwds) { + ssh->portfwds = newtree234(ssh_portcmp); + } else { + /* + * Go through the existing port forwardings and tag them + * with status==DESTROY. Any that we want to keep will be + * re-enabled (status==KEEP) as we go through the + * configuration and find out which bits are the same as + * they were before. + */ + struct ssh_portfwd *epf; + int i; + for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++) + epf->status = DESTROY; + } + + while (*portfwd_strptr) { + char address_family, type; + int sport,dport,sserv,dserv; + char sports[256], dports[256], saddr[256], host[256]; + int n; + + address_family = 'A'; + type = 'L'; + if (*portfwd_strptr == 'A' || + *portfwd_strptr == '4' || + *portfwd_strptr == '6') + address_family = *portfwd_strptr++; + if (*portfwd_strptr == 'L' || + *portfwd_strptr == 'R' || + *portfwd_strptr == 'D') + type = *portfwd_strptr++; + + saddr[0] = '\0'; + + n = 0; + while (*portfwd_strptr && *portfwd_strptr != '\t') { + if (*portfwd_strptr == ':') { + /* + * We've seen a colon in the middle of the + * source port number. This means that + * everything we've seen until now is the + * source _address_, so we'll move it into + * saddr and start sports from the beginning + * again. + */ + portfwd_strptr++; + sports[n] = '\0'; + if (ssh->version == 1 && type == 'R') { + logeventf(ssh, "SSH-1 cannot handle remote source address " + "spec \"%s\"; ignoring", sports); + } else + strcpy(saddr, sports); + n = 0; + } + if (n < lenof(sports)-1) sports[n++] = *portfwd_strptr++; + } + sports[n] = 0; + if (type != 'D') { + if (*portfwd_strptr == '\t') + portfwd_strptr++; + n = 0; + while (*portfwd_strptr && *portfwd_strptr != ':') { + if (n < lenof(host)-1) host[n++] = *portfwd_strptr++; + } + host[n] = 0; + if (*portfwd_strptr == ':') + portfwd_strptr++; + n = 0; + while (*portfwd_strptr) { + if (n < lenof(dports)-1) dports[n++] = *portfwd_strptr++; + } + dports[n] = 0; + portfwd_strptr++; + dport = atoi(dports); + dserv = 0; + if (dport == 0) { + dserv = 1; + dport = net_service_lookup(dports); + if (!dport) { + logeventf(ssh, "Service lookup failed for destination" + " port \"%s\"", dports); + } + } + } else { + while (*portfwd_strptr) portfwd_strptr++; + host[0] = 0; + dports[0] = 0; + dport = dserv = -1; + portfwd_strptr++; /* eat the NUL and move to next one */ + } + sport = atoi(sports); + sserv = 0; + if (sport == 0) { + sserv = 1; + sport = net_service_lookup(sports); + if (!sport) { + logeventf(ssh, "Service lookup failed for source" + " port \"%s\"", sports); + } + } + if (sport && dport) { + /* Set up a description of the source port. */ + struct ssh_portfwd *pfrec, *epfrec; + + pfrec = snew(struct ssh_portfwd); + pfrec->type = type; + pfrec->saddr = *saddr ? dupstr(saddr) : NULL; + pfrec->sserv = sserv ? dupstr(sports) : NULL; + pfrec->sport = sport; + pfrec->daddr = *host ? dupstr(host) : NULL; + pfrec->dserv = dserv ? dupstr(dports) : NULL; + pfrec->dport = dport; + pfrec->local = NULL; + pfrec->remote = NULL; + pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 : + address_family == '6' ? ADDRTYPE_IPV6 : + ADDRTYPE_UNSPEC); + + epfrec = add234(ssh->portfwds, pfrec); + if (epfrec != pfrec) { + /* + * We already have a port forwarding with precisely + * these parameters. Hence, no need to do anything; + * simply tag the existing one as KEEP. + */ + epfrec->status = KEEP; + free_portfwd(pfrec); + } else { + pfrec->status = CREATE; + } + } + } + + /* + * Now go through and destroy any port forwardings which were + * not re-enabled. + */ + for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++) + if (epf->status == DESTROY) { + char *message; + + message = dupprintf("%s port forwarding from %s%s%d", + epf->type == 'L' ? "local" : + epf->type == 'R' ? "remote" : "dynamic", + epf->saddr ? epf->saddr : "", + epf->saddr ? ":" : "", + epf->sport); + + if (epf->type != 'D') { + char *msg2 = dupprintf("%s to %s:%d", message, + epf->daddr, epf->dport); + sfree(message); + message = msg2; + } + + logeventf(ssh, "Cancelling %s", message); + sfree(message); + + if (epf->remote) { + struct ssh_rportfwd *rpf = epf->remote; + struct Packet *pktout; + + /* + * Cancel the port forwarding at the server + * end. + */ + if (ssh->version == 1) { + /* + * We cannot cancel listening ports on the + * server side in SSH-1! There's no message + * to support it. Instead, we simply remove + * the rportfwd record from the local end + * so that any connections the server tries + * to make on it are rejected. + */ + } else { + pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST); + ssh2_pkt_addstring(pktout, "cancel-tcpip-forward"); + ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */ + if (epf->saddr) { + ssh2_pkt_addstring(pktout, epf->saddr); + } else if (ssh->cfg.rport_acceptall) { + /* XXX: ssh->cfg.rport_acceptall may not represent + * what was used to open the original connection, + * since it's reconfigurable. */ + ssh2_pkt_addstring(pktout, "0.0.0.0"); + } else { + ssh2_pkt_addstring(pktout, "127.0.0.1"); + } + ssh2_pkt_adduint32(pktout, epf->sport); + ssh2_pkt_send(ssh, pktout); + } + + del234(ssh->rportfwds, rpf); + free_rportfwd(rpf); + } else if (epf->local) { + pfd_terminate(epf->local); + } + + delpos234(ssh->portfwds, i); + free_portfwd(epf); + i--; /* so we don't skip one in the list */ + } + + /* + * And finally, set up any new port forwardings (status==CREATE). + */ + for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++) + if (epf->status == CREATE) { + char *sportdesc, *dportdesc; + sportdesc = dupprintf("%s%s%s%s%d%s", + epf->saddr ? epf->saddr : "", + epf->saddr ? ":" : "", + epf->sserv ? epf->sserv : "", + epf->sserv ? "(" : "", + epf->sport, + epf->sserv ? ")" : ""); + if (epf->type == 'D') { + dportdesc = NULL; + } else { + dportdesc = dupprintf("%s:%s%s%d%s", + epf->daddr, + epf->dserv ? epf->dserv : "", + epf->dserv ? "(" : "", + epf->dport, + epf->dserv ? ")" : ""); + } + + if (epf->type == 'L') { + const char *err = pfd_addforward(epf->daddr, epf->dport, + epf->saddr, epf->sport, + ssh, cfg, + &epf->local, + epf->addressfamily); + + logeventf(ssh, "Local %sport %s forwarding to %s%s%s", + epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " : + epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "", + sportdesc, dportdesc, + err ? " failed: " : "", err ? err : ""); + } else if (epf->type == 'D') { + const char *err = pfd_addforward(NULL, -1, + epf->saddr, epf->sport, + ssh, cfg, + &epf->local, + epf->addressfamily); + + logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s", + epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " : + epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "", + sportdesc, + err ? " failed: " : "", err ? err : ""); + } else { + struct ssh_rportfwd *pf; + + /* + * Ensure the remote port forwardings tree exists. + */ + if (!ssh->rportfwds) { + if (ssh->version == 1) + ssh->rportfwds = newtree234(ssh_rportcmp_ssh1); + else + ssh->rportfwds = newtree234(ssh_rportcmp_ssh2); + } + + pf = snew(struct ssh_rportfwd); + strncpy(pf->dhost, epf->daddr, lenof(pf->dhost)-1); + pf->dhost[lenof(pf->dhost)-1] = '\0'; + pf->dport = epf->dport; + pf->sport = epf->sport; + if (add234(ssh->rportfwds, pf) != pf) { + logeventf(ssh, "Duplicate remote port forwarding to %s:%d", + epf->daddr, epf->dport); + sfree(pf); + } else { + logeventf(ssh, "Requesting remote port %s" + " forward to %s", sportdesc, dportdesc); + + pf->sportdesc = sportdesc; + sportdesc = NULL; + epf->remote = pf; + pf->pfrec = epf; + + if (ssh->version == 1) { + send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST, + PKT_INT, epf->sport, + PKT_STR, epf->daddr, + PKT_INT, epf->dport, + PKT_END); + ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS, + SSH1_SMSG_FAILURE, + ssh_rportfwd_succfail, pf); + } else { + struct Packet *pktout; + pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST); + ssh2_pkt_addstring(pktout, "tcpip-forward"); + ssh2_pkt_addbool(pktout, 1);/* want reply */ + if (epf->saddr) { + ssh2_pkt_addstring(pktout, epf->saddr); + } else if (cfg->rport_acceptall) { + ssh2_pkt_addstring(pktout, "0.0.0.0"); + } else { + ssh2_pkt_addstring(pktout, "127.0.0.1"); + } + ssh2_pkt_adduint32(pktout, epf->sport); + ssh2_pkt_send(ssh, pktout); + + ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS, + SSH2_MSG_REQUEST_FAILURE, + ssh_rportfwd_succfail, pf); + } + } + } + sfree(sportdesc); + sfree(dportdesc); + } +} + static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin) { char *string; @@ -3559,6 +4207,7 @@ static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin) logevent ("Opening X11 forward connection succeeded"); c->remoteid = remoteid; + c->halfopen = FALSE; c->localid = alloc_channel_id(ssh); c->closes = 0; c->v.v1.throttling = 0; @@ -3587,6 +4236,7 @@ static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin) c = snew(struct ssh_channel); c->ssh = ssh; c->remoteid = remoteid; + c->halfopen = FALSE; c->localid = alloc_channel_id(ssh); c->closes = 0; c->v.v1.throttling = 0; @@ -3604,10 +4254,10 @@ static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin) /* Remote side is trying to open a channel to talk to a * forwarded port. Give them back a local channel number. */ struct ssh_channel *c; - struct ssh_rportfwd pf; + struct ssh_rportfwd pf, *pfp; int remoteid; int hostsize, port; - char *host, buf[1024]; + char *host; const char *e; c = snew(struct ssh_channel); c->ssh = ssh; @@ -3621,28 +4271,26 @@ static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin) memcpy(pf.dhost, host, hostsize); pf.dhost[hostsize] = '\0'; pf.dport = port; + pfp = find234(ssh->rportfwds, &pf, NULL); - if (find234(ssh->rportfwds, &pf, NULL) == NULL) { - sprintf(buf, "Rejected remote port open request for %s:%d", - pf.dhost, port); - logevent(buf); + if (pfp == NULL) { + logeventf(ssh, "Rejected remote port open request for %s:%d", + pf.dhost, port); send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE, PKT_INT, remoteid, PKT_END); } else { - sprintf(buf, "Received remote port open request for %s:%d", - pf.dhost, port); - logevent(buf); + logeventf(ssh, "Received remote port open request for %s:%d", + pf.dhost, port); e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port, - c, &ssh->cfg); + c, &ssh->cfg, pfp->pfrec->addressfamily); if (e != NULL) { - char buf[256]; - sprintf(buf, "Port open failed: %s", e); - logevent(buf); + logeventf(ssh, "Port open failed: %s", e); sfree(c); send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE, PKT_INT, remoteid, PKT_END); } else { c->remoteid = remoteid; + c->halfopen = FALSE; c->localid = alloc_channel_id(ssh); c->closes = 0; c->v.v1.throttling = 0; @@ -3665,6 +4313,7 @@ static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin) c = find234(ssh->channels, &remoteid, ssh_channelfind); if (c && c->type == CHAN_SOCKDATA_DORMANT) { c->remoteid = localid; + c->halfopen = FALSE; c->type = CHAN_SOCKDATA; c->v.v1.throttling = 0; pfd_confirm(c->u.pfd.s); @@ -3702,7 +4351,7 @@ static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin) unsigned i = ssh_pkt_getuint32(pktin); struct ssh_channel *c; c = find234(ssh->channels, &i, ssh_channelfind); - if (c && ((int)c->remoteid) != -1) { + if (c && !c->halfopen) { int closetype; closetype = (pktin->type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2); @@ -3763,7 +4412,7 @@ static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin) /* Data for an agent message. Buffer it. */ while (len > 0) { if (c->u.a.lensofar < 4) { - int l = min(4 - c->u.a.lensofar, len); + unsigned int l = min(4 - c->u.a.lensofar, len); memcpy(c->u.a.msglen + c->u.a.lensofar, p, l); p += l; @@ -3778,7 +4427,7 @@ static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin) memcpy(c->u.a.message, c->u.a.msglen, 4); } if (c->u.a.lensofar >= 4 && len > 0) { - int l = + unsigned int l = min(c->u.a.totallen - c->u.a.lensofar, len); memcpy(c->u.a.message + c->u.a.lensofar, p, @@ -3811,11 +4460,8 @@ static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin) static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin) { - char buf[100]; ssh->exitcode = ssh_pkt_getuint32(pktin); - sprintf(buf, "Server sent command exit status %d", - ssh->exitcode); - logevent(buf); + logeventf(ssh, "Server sent command exit status %d", ssh->exitcode); send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END); /* * In case `helpful' firewalls or proxies tack @@ -3824,6 +4470,7 @@ static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin) * encrypted packet, we close the session once * we've sent EXIT_CONFIRMATION. */ + ssh->close_expected = TRUE; ssh_closing((Plug)ssh, NULL, 0, 0); } @@ -3896,164 +4543,8 @@ static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen, } } - { - char type; - int n; - int sport,dport,sserv,dserv; - char sports[256], dports[256], saddr[256], host[256]; - - ssh->rportfwds = newtree234(ssh_rportcmp_ssh1); - /* Add port forwardings. */ - ssh->portfwd_strptr = ssh->cfg.portfwd; - while (*ssh->portfwd_strptr) { - type = *ssh->portfwd_strptr++; - saddr[0] = '\0'; - n = 0; - while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') { - if (*ssh->portfwd_strptr == ':') { - /* - * We've seen a colon in the middle of the - * source port number. This means that - * everything we've seen until now is the - * source _address_, so we'll move it into - * saddr and start sports from the beginning - * again. - */ - ssh->portfwd_strptr++; - sports[n] = '\0'; - strcpy(saddr, sports); - n = 0; - } - if (n < 255) sports[n++] = *ssh->portfwd_strptr++; - } - sports[n] = 0; - if (type != 'D') { - if (*ssh->portfwd_strptr == '\t') - ssh->portfwd_strptr++; - n = 0; - while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') { - if (n < 255) host[n++] = *ssh->portfwd_strptr++; - } - host[n] = 0; - if (*ssh->portfwd_strptr == ':') - ssh->portfwd_strptr++; - n = 0; - while (*ssh->portfwd_strptr) { - if (n < 255) dports[n++] = *ssh->portfwd_strptr++; - } - dports[n] = 0; - ssh->portfwd_strptr++; - dport = atoi(dports); - dserv = 0; - if (dport == 0) { - dserv = 1; - dport = net_service_lookup(dports); - if (!dport) { - logeventf(ssh, "Service lookup failed for" - " destination port \"%s\"", dports); - } - } - } else { - while (*ssh->portfwd_strptr) ssh->portfwd_strptr++; - dport = dserv = -1; - ssh->portfwd_strptr++; /* eat the NUL and move to next one */ - } - sport = atoi(sports); - sserv = 0; - if (sport == 0) { - sserv = 1; - sport = net_service_lookup(sports); - if (!sport) { - logeventf(ssh, "Service lookup failed for source" - " port \"%s\"", sports); - } - } - if (sport && dport) { - /* Set up a description of the source port. */ - static char *sportdesc; - sportdesc = dupprintf("%.*s%.*s%.*s%.*s%d%.*s", - (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL, - (int)(*saddr?1:0), ":", - (int)(sserv ? strlen(sports) : 0), sports, - sserv, "(", sport, sserv, ")"); - if (type == 'L') { - /* Verbose description of the destination port */ - char *dportdesc = dupprintf("%s:%.*s%.*s%d%.*s", - host, - (int)(dserv ? strlen(dports) : 0), dports, - dserv, "(", dport, dserv, ")"); - const char *err = pfd_addforward(host, dport, - *saddr ? saddr : NULL, - sport, ssh, &ssh->cfg); - if (err) { - logeventf(ssh, "Local port %s forward to %s" - " failed: %s", sportdesc, dportdesc, err); - } else { - logeventf(ssh, "Local port %s forwarding to %s", - sportdesc, dportdesc); - } - sfree(dportdesc); - } else if (type == 'D') { - const char *err = pfd_addforward(NULL, -1, - *saddr ? saddr : NULL, - sport, ssh, &ssh->cfg); - if (err) { - logeventf(ssh, "Local port %s SOCKS dynamic forward" - " setup failed: %s", sportdesc, err); - } else { - logeventf(ssh, "Local port %s doing SOCKS" - " dynamic forwarding", sportdesc); - } - } else { - struct ssh_rportfwd *pf; - pf = snew(struct ssh_rportfwd); - strcpy(pf->dhost, host); - pf->dport = dport; - if (*saddr) { - logeventf(ssh, - "SSH1 cannot handle source address spec \"%s:%d\"; ignoring", - saddr, sport); - } - if (add234(ssh->rportfwds, pf) != pf) { - logeventf(ssh, - "Duplicate remote port forwarding to %s:%d", - host, dport); - sfree(pf); - } else { - logeventf(ssh, "Requesting remote port %.*s%.*s%d%.*s" - " forward to %s:%.*s%.*s%d%.*s", - (int)(sserv ? strlen(sports) : 0), sports, - sserv, "(", sport, sserv, ")", - host, - (int)(dserv ? strlen(dports) : 0), dports, - dserv, "(", dport, dserv, ")"); - send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST, - PKT_INT, sport, - PKT_STR, host, - PKT_INT, dport, - PKT_END); - do { - crReturnV; - } while (!pktin); - if (pktin->type != SSH1_SMSG_SUCCESS - && pktin->type != SSH1_SMSG_FAILURE) { - bombout(("Protocol confusion")); - crStopV; - } else if (pktin->type == SSH1_SMSG_FAILURE) { - c_write_str(ssh, "Server refused port" - " forwarding\r\n"); - logevent("Server refused this port forwarding"); - } else { - logevent("Remote port forwarding enabled"); - ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = - ssh1_msg_port_open; - } - } - } - sfree(sportdesc); - } - } - } + ssh_setup_portfwd(ssh, &ssh->cfg); + ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open; if (!ssh->cfg.nopty) { /* Unpick the terminal-speed string. */ @@ -4110,12 +4601,14 @@ static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen, /* * Start the shell or command. * - * Special case: if the first-choice command is an SSH2 + * Special case: if the first-choice command is an SSH-2 * subsystem (hence not usable here) and the second choice * exists, we fall straight back to that. */ { char *cmd = ssh->cfg.remote_cmd_ptr; + + if (!cmd) cmd = ssh->cfg.remote_cmd; if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) { cmd = ssh->cfg.remote_cmd_ptr2; @@ -4173,17 +4666,15 @@ static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen, } /* - * Handle the top-level SSH2 protocol. + * Handle the top-level SSH-2 protocol. */ static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin) { - char *buf, *msg; + char *msg; int msglen; ssh_pkt_getstring(pktin, &msg, &msglen); - buf = dupprintf("Remote debug message: %.*s", msglen, msg); - logevent(buf); - sfree(buf); + logeventf(ssh, "Remote debug message: %.*s", msglen, msg); } static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin) @@ -4196,7 +4687,7 @@ static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin) bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg)); } -void ssh_msg_ignore(Ssh ssh, struct Packet *pktin) +static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin) { /* Do nothing, because we're ignoring it! Duhh. */ } @@ -4219,9 +4710,10 @@ static void ssh1_protocol_setup(Ssh ssh) ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug; } -static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, +static void ssh1_protocol(Ssh ssh, void *vin, int inlen, struct Packet *pktin) { + unsigned char *in=(unsigned char*)vin; if (ssh->state == SSH_STATE_CLOSED) return; @@ -4272,7 +4764,29 @@ static int in_commasep_string(char *needle, char *haystack, int haylen) } /* - * SSH2 key creation method. + * Similar routine for checking whether we have the first string in a list. + */ +static int first_in_commasep_string(char *needle, char *haystack, int haylen) +{ + int needlen; + if (!needle || !haystack) /* protect against null pointers */ + return 0; + needlen = strlen(needle); + /* + * Is it at the start of the string? + */ + if (haylen >= needlen && /* haystack is long enough */ + !memcmp(needle, haystack, needlen) && /* initial match */ + (haylen == needlen || haystack[needlen] == ',') + /* either , or EOS follows */ + ) + return 1; + return 0; +} + + +/* + * SSH-2 key creation method. */ static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, unsigned char *sessid, char chr, @@ -4297,13 +4811,14 @@ static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, } /* - * Handle the SSH2 transport layer. + * Handle the SSH-2 transport layer. */ -static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, +static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, struct Packet *pktin) { + unsigned char *in = (unsigned char *)vin; struct do_ssh2_transport_state { - int nbits, pbits, warn; + int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher; Bignum p, g, e, f, K; int kex_init_value, kex_reply_value; const struct ssh_mac **maclist; @@ -4318,11 +4833,16 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, 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; - int first_kex; + int got_session_id, activated_authconn; struct Packet *pktout; + int dlgret; + int guessok; + int ignorepkt; }; crState(do_ssh2_transport_state); @@ -4332,10 +4852,49 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, s->csmac_tobe = s->scmac_tobe = NULL; s->cscomp_tobe = s->sccomp_tobe = NULL; - s->first_kex = 1; + s->got_session_id = s->activated_authconn = FALSE; + /* + * Be prepared to work around the buggy MAC problem. + */ + if (ssh->remote_bugs & BUG_SSH2_HMAC) + s->maclist = buggymacs, s->nmacs = lenof(buggymacs); + else + s->maclist = macs, s->nmacs = lenof(macs); + + begin_key_exchange: + ssh->pkt_ctx &= ~SSH2_PKTCTX_KEX_MASK; { - int i; + int i, j, commalist_started; + + /* + * 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; + } + } + /* * Set up the preferred ciphers. (NULL => warn below here) */ @@ -4365,27 +4924,14 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, break; } } - } - - /* - * Set up preferred compression. - */ - if (ssh->cfg.compression) - s->preferred_comp = &ssh_zlib; - else - s->preferred_comp = &ssh_comp_none; - - /* - * Be prepared to work around the buggy MAC problem. - */ - if (ssh->remote_bugs & BUG_SSH2_HMAC) - s->maclist = buggymacs, s->nmacs = lenof(buggymacs); - else - s->maclist = macs, s->nmacs = lenof(macs); - begin_key_exchange: - { - int i, j, cipherstr_started; + /* + * Set up preferred compression. + */ + if (ssh->cfg.compression) + s->preferred_comp = &ssh_zlib; + else + s->preferred_comp = &ssh_comp_none; /* * Enable queueing of outgoing auth- or connection-layer @@ -4406,13 +4952,14 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, 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); @@ -4423,28 +4970,28 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, } /* 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. */ @@ -4508,7 +5055,7 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, * to. */ { - char *str; + char *str, *preferred; int i, j, len; if (pktin->type != SSH2_MSG_KEXINIT) { @@ -4523,17 +5070,35 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, s->scmac_tobe = NULL; s->cscomp_tobe = NULL; s->sccomp_tobe = NULL; + s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE; + 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]; - break; + + preferred = NULL; + for (i = 0; i < s->n_preferred_kex; i++) { + const struct ssh_kex *k = s->preferred_kex[i]; + if (!k) { + s->warn_kex = TRUE; + } else { + if (!preferred) preferred = k->name; + if (in_commasep_string(k->name, str, len)) + ssh->kex = k; } + if (ssh->kex) + break; + } + if (!ssh->kex) { + bombout(("Couldn't agree a key exchange algorithm (available: %s)", + str ? str : "(null)")); + crStop(0); } + /* + * Note that the server's guess is considered wrong if it doesn't match + * the first algorithm in our list, even if it's still the algorithm + * we end up using. + */ + s->guessok = first_in_commasep_string(preferred, str, len); 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)) { @@ -4541,12 +5106,13 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, break; } } + s->guessok = s->guessok && + first_in_commasep_string(hostkey_algs[0]->name, str, len); ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */ - s->warn = 0; for (i = 0; i < s->n_preferred_ciphers; i++) { const struct ssh2_ciphers *c = s->preferred_ciphers[i]; if (!c) { - s->warn = 1; + s->warn_cscipher = TRUE; } else { for (j = 0; j < c->nciphers; j++) { if (in_commasep_string(c->list[j]->name, str, len)) { @@ -4555,11 +5121,8 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, } } } - if (s->cscipher_tobe) { - if (s->warn) - askcipher(ssh->frontend, s->cscipher_tobe->name, 1); + if (s->cscipher_tobe) break; - } } if (!s->cscipher_tobe) { bombout(("Couldn't agree a client-to-server cipher (available: %s)", @@ -4568,11 +5131,10 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, } ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */ - s->warn = 0; for (i = 0; i < s->n_preferred_ciphers; i++) { const struct ssh2_ciphers *c = s->preferred_ciphers[i]; if (!c) { - s->warn = 1; + s->warn_sccipher = TRUE; } else { for (j = 0; j < c->nciphers; j++) { if (in_commasep_string(c->list[j]->name, str, len)) { @@ -4581,11 +5143,8 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, } } } - if (s->sccipher_tobe) { - if (s->warn) - askcipher(ssh->frontend, s->sccipher_tobe->name, 2); + if (s->sccipher_tobe) break; - } } if (!s->sccipher_tobe) { bombout(("Couldn't agree a server-to-client cipher (available: %s)", @@ -4625,6 +5184,86 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, break; } } + ssh_pkt_getstring(pktin, &str, &len); /* client->server language */ + ssh_pkt_getstring(pktin, &str, &len); /* server->client language */ + s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok; + + if (s->warn_kex) { + ssh_set_frozen(ssh, 1); + s->dlgret = askalg(ssh->frontend, "key-exchange algorithm", + ssh->kex->name, + ssh_dialog_callback, ssh); + if (s->dlgret < 0) { + do { + crReturn(0); + if (pktin) { + bombout(("Unexpected data from server while" + " waiting for user response")); + crStop(0); + } + } while (pktin || inlen > 0); + s->dlgret = ssh->user_response; + } + ssh_set_frozen(ssh, 0); + if (s->dlgret == 0) { + ssh->close_expected = TRUE; + ssh_closing((Plug)ssh, NULL, 0, 0); + crStop(0); + } + } + + if (s->warn_cscipher) { + ssh_set_frozen(ssh, 1); + s->dlgret = askalg(ssh->frontend, + "client-to-server cipher", + s->cscipher_tobe->name, + ssh_dialog_callback, ssh); + if (s->dlgret < 0) { + do { + crReturn(0); + if (pktin) { + bombout(("Unexpected data from server while" + " waiting for user response")); + crStop(0); + } + } while (pktin || inlen > 0); + s->dlgret = ssh->user_response; + } + ssh_set_frozen(ssh, 0); + if (s->dlgret == 0) { + ssh->close_expected = TRUE; + ssh_closing((Plug)ssh, NULL, 0, 0); + crStop(0); + } + } + + if (s->warn_sccipher) { + ssh_set_frozen(ssh, 1); + s->dlgret = askalg(ssh->frontend, + "server-to-client cipher", + s->sccipher_tobe->name, + ssh_dialog_callback, ssh); + if (s->dlgret < 0) { + do { + crReturn(0); + if (pktin) { + bombout(("Unexpected data from server while" + " waiting for user response")); + crStop(0); + } + } while (pktin || inlen > 0); + s->dlgret = ssh->user_response; + } + ssh_set_frozen(ssh, 0); + if (s->dlgret == 0) { + ssh->close_expected = TRUE; + ssh_closing((Plug)ssh, NULL, 0, 0); + crStop(0); + } + } + + if (s->ignorepkt) /* first_kex_packet_follows */ + crWaitUntil(pktin); /* Ignore packet */ } /* @@ -4648,7 +5287,7 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, * 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; /* @@ -4671,30 +5310,35 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, 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"); /* * Now generate and send e for Diffie-Hellman. */ + set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */ s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2); s->pktout = ssh2_pkt_init(s->kex_init_value); ssh2_pkt_addmp(s->pktout, s->e); ssh2_pkt_send_noqueue(ssh, s->pktout); + set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */ crWaitUntil(pktin); if (pktin->type != s->kex_reply_value) { bombout(("expected key exchange reply packet from server")); crStop(0); } + set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */ ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen); s->f = ssh2_pkt_getmp(pktin); if (!s->f) { @@ -4705,6 +5349,10 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, s->K = dh_find_K(ssh->kex_ctx, s->f); + /* We assume everything from now on will be quick, and it might + * involve user interaction. */ + set_busy_status(ssh->frontend, BUSY_NOT); + sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen); if (ssh->kex == &ssh_diffiehellman_gex) { sha_uint32(&ssh->exhash, s->pbits); @@ -4738,10 +5386,30 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, */ s->keystr = ssh->hostkey->fmtkey(s->hkey); s->fingerprint = ssh->hostkey->fingerprint(s->hkey); - verify_ssh_host_key(ssh->frontend, - ssh->savedhost, ssh->savedport, ssh->hostkey->keytype, - s->keystr, s->fingerprint); - if (s->first_kex) { /* don't bother logging this in rekeys */ + 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 { + 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->close_expected = TRUE; + ssh_closing((Plug)ssh, NULL, 0, 0); + crStop(0); + } + if (!s->got_session_id) { /* don't bother logging this in rekeys */ logevent("Host key fingerprint is:"); logevent(s->fingerprint); } @@ -4754,9 +5422,11 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, * the session id, used in session key construction and * authentication. */ - if (s->first_kex) + if (!s->got_session_id) { memcpy(ssh->v2_session_id, s->exchange_hash, sizeof(s->exchange_hash)); + s->got_session_id = TRUE; + } /* * Send SSH2_MSG_NEWKEYS. @@ -4874,10 +5544,24 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, } /* - * Key exchange is over. Schedule a timer for our next rekey. + * Key exchange is over. Loop straight back round if we have a + * deferred rekey reason. + */ + if (ssh->deferred_rekey_reason) { + logevent(ssh->deferred_rekey_reason); + pktin = NULL; + ssh->deferred_rekey_reason = NULL; + goto begin_key_exchange; + } + + /* + * Otherwise, schedule a timer for our next rekey. */ ssh->kex_in_progress = FALSE; - ssh->next_rekey = schedule_timer(REKEY_TIMEOUT, ssh2_timer, ssh); + ssh->last_rekey = GETTICKCOUNT(); + if (ssh->cfg.ssh_rekey_time != 0) + ssh->next_rekey = schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC, + ssh2_timer, ssh); /* * If this is the first key exchange phase, we must pass the @@ -4887,10 +5571,10 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because * it would only confuse the layer above. */ - if (!s->first_kex) { + if (s->activated_authconn) { crReturn(1); } - s->first_kex = 0; + s->activated_authconn = TRUE; /* * Now we're encrypting. Begin returning 1 to the protocol main @@ -4905,12 +5589,34 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, */ while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) || (!pktin && inlen == -1))) { + wait_for_rekey: crReturn(1); } if (pktin) { logevent("Server initiated key re-exchange"); } else { - logevent((char *)in); + /* + * Special case: if the server bug is set that doesn't + * allow rekeying, we give a different log message and + * continue waiting. (If such a server _initiates_ a rekey, + * we process it anyway!) + */ + if ((ssh->remote_bugs & BUG_SSH2_REKEY)) { + logeventf(ssh, "Server bug prevents key re-exchange (%s)", + (char *)in); + /* Reset the counters, so that at least this message doesn't + * hit the event log _too_ often. */ + ssh->outgoing_data_size = 0; + ssh->incoming_data_size = 0; + if (ssh->cfg.ssh_rekey_time != 0) { + ssh->next_rekey = + schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC, + ssh2_timer, ssh); + } + goto wait_for_rekey; /* this is utterly horrid */ + } else { + logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in); + } } goto begin_key_exchange; @@ -4918,7 +5624,7 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, } /* - * Add data to an SSH2 channel output buffer. + * Add data to an SSH-2 channel output buffer. */ static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len) @@ -4927,7 +5633,7 @@ static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, } /* - * Attempt to send data on an SSH2 channel. + * Attempt to send data on an SSH-2 channel. */ static int ssh2_try_send(struct ssh_channel *c) { @@ -4960,8 +5666,34 @@ static int ssh2_try_send(struct ssh_channel *c) return bufchain_size(&c->v.v2.outbuffer); } +static void ssh2_try_send_and_unthrottle(struct ssh_channel *c) +{ + int bufsize; + if (c->closes) + return; /* don't send on closing channels */ + bufsize = ssh2_try_send(c); + if (bufsize == 0) { + switch (c->type) { + case CHAN_MAINSESSION: + /* stdin need not receive an unthrottle + * notification since it will be polled */ + break; + case CHAN_X11: + x11_unthrottle(c->u.x11.s); + break; + case CHAN_AGENT: + /* agent sockets are request/response and need no + * buffer management */ + break; + case CHAN_SOCKDATA: + pfd_unthrottle(c->u.pfd.s); + break; + } + } +} + /* - * Potentially enlarge the window on an SSH2 channel. + * Potentially enlarge the window on an SSH-2 channel. */ static void ssh2_set_window(struct ssh_channel *c, unsigned newwin) { @@ -4975,7 +5707,14 @@ static void ssh2_set_window(struct ssh_channel *c, unsigned newwin) if (c->closes != 0) return; - if (newwin > c->v.v2.locwindow) { + /* + * Only send a WINDOW_ADJUST if there's significantly more window + * available than the other end thinks there is. This saves us + * sending a WINDOW_ADJUST for every character in a shell session. + * + * "Significant" is arbitrarily defined as half the window size. + */ + if (newwin > c->v.v2.locwindow * 2) { struct Packet *pktout; pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST); @@ -4991,8 +5730,10 @@ static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin) unsigned i = ssh_pkt_getuint32(pktin); struct ssh_channel *c; c = find234(ssh->channels, &i, ssh_channelfind); - if (c && !c->closes) + if (c && !c->closes) { c->v.v2.remwindow += ssh_pkt_getuint32(pktin); + ssh2_try_send_and_unthrottle(c); + } } static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin) @@ -5027,7 +5768,7 @@ static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin) case CHAN_AGENT: while (length > 0) { if (c->u.a.lensofar < 4) { - int l = min(4 - c->u.a.lensofar, length); + unsigned int l = min(4 - c->u.a.lensofar, length); memcpy(c->u.a.msglen + c->u.a.lensofar, data, l); data += l; @@ -5042,7 +5783,7 @@ static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin) memcpy(c->u.a.message, c->u.a.msglen, 4); } if (c->u.a.lensofar >= 4 && length > 0) { - int l = + unsigned int l = min(c->u.a.totallen - c->u.a.lensofar, length); memcpy(c->u.a.message + c->u.a.lensofar, @@ -5106,7 +5847,7 @@ static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin) struct Packet *pktout; c = find234(ssh->channels, &i, ssh_channelfind); - if (!c || ((int)c->remoteid) == -1) { + if (!c || c->halfopen) { bombout(("Received CHANNEL_CLOSE for %s channel %d\n", c ? "half-open" : "nonexistent", i)); return; @@ -5151,7 +5892,7 @@ static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin) /* * We used to send SSH_MSG_DISCONNECT here, * because I'd believed that _every_ conforming - * SSH2 connection had to end with a disconnect + * SSH-2 connection had to end with a disconnect * being sent by at least one side; apparently * I was wrong and it's perfectly OK to * unceremoniously slam the connection shut @@ -5165,6 +5906,7 @@ static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin) ssh2_pkt_addstring(s->pktout, "en"); /* language tag */ ssh2_pkt_send_noqueue(ssh, s->pktout); #endif + ssh->close_expected = TRUE; ssh_closing((Plug)ssh, NULL, 0, 0); } } @@ -5181,6 +5923,7 @@ static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin) if (c->type != CHAN_SOCKDATA_DORMANT) return; /* dunno why they're confirming this */ c->remoteid = ssh_pkt_getuint32(pktin); + c->halfopen = FALSE; c->type = CHAN_SOCKDATA; c->v.v2.remwindow = ssh_pkt_getuint32(pktin); c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin); @@ -5212,7 +5955,6 @@ static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin) unsigned reason_code; char *reason_string; int reason_length; - char *message; struct ssh_channel *c; c = find234(ssh->channels, &i, ssh_channelfind); if (!c) @@ -5224,11 +5966,8 @@ static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin) if (reason_code >= lenof(reasons)) reason_code = 0; /* ensure reasons[reason_code] in range */ ssh_pkt_getstring(pktin, &reason_string, &reason_length); - message = dupprintf("Forwarded connection refused by" - " server: %s [%.*s]", reasons[reason_code], - reason_length, reason_string); - logevent(message); - sfree(message); + logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]", + reasons[reason_code], reason_length, reason_string); pfd_close(c->u.pfd.s); @@ -5265,6 +6004,7 @@ static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin) ssh2_pkt_addstring(pktout, "en"); /* language tag */ ssh2_pkt_send_noqueue(ssh, pktout); connection_fatal(ssh->frontend, "%s", buf); + ssh->close_expected = TRUE; ssh_closing((Plug)ssh, NULL, 0, 0); return; } @@ -5315,7 +6055,7 @@ static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin) if (q >= 0 && q+4 <= len) { \ q = q + 4 + GET_32BIT(p+q); \ if (q >= 0 && q+4 <= len && \ - (q = q + 4 + GET_32BIT(p+q)) && q == len) \ + ((q = q + 4 + GET_32BIT(p+q))!= 0) && q == len) \ result = TRUE; \ } \ } while(0) @@ -5462,7 +6202,8 @@ static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin) const char *e = pfd_newconnect(&c->u.pfd.s, realpf->dhost, realpf->dport, c, - &ssh->cfg); + &ssh->cfg, + realpf->pfrec->addressfamily); logeventf(ssh, "Attempting to forward remote port to " "%s:%d", realpf->dhost, realpf->dport); if (e != NULL) { @@ -5486,6 +6227,7 @@ static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin) } c->remoteid = remid; + c->halfopen = FALSE; if (error) { pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE); ssh2_pkt_adduint32(pktout, c->remoteid); @@ -5507,13 +6249,13 @@ static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin) ssh2_pkt_adduint32(pktout, c->remoteid); ssh2_pkt_adduint32(pktout, c->localid); ssh2_pkt_adduint32(pktout, c->v.v2.locwindow); - ssh2_pkt_adduint32(pktout, 0x4000UL); /* our max pkt size */ + ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */ ssh2_pkt_send(ssh, pktout); } } /* - * Handle the SSH2 userauth and connection layers. + * Handle the SSH-2 userauth and connection layers. */ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, struct Packet *pktin) @@ -5534,8 +6276,8 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET } type; int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter; - int tried_pubkey_config, tried_agent, tried_keyb_inter; - int kbd_inter_running; + int tried_pubkey_config, tried_agent; + int kbd_inter_running, kbd_inter_refused; int we_are_in; int num_prompts, curr_prompt, echo; char username[100]; @@ -5617,6 +6359,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, * Terminate. */ logevent("No username provided. Abandoning session."); + ssh->close_expected = TRUE; ssh_closing((Plug)ssh, NULL, 0, 0); crStopV; } @@ -5664,8 +6407,8 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, s->tried_pubkey_config = FALSE; s->tried_agent = FALSE; - s->tried_keyb_inter = FALSE; s->kbd_inter_running = FALSE; + s->kbd_inter_refused = FALSE; /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */ if (!filename_is_null(ssh->cfg.keyfile)) { int keytype; @@ -5732,6 +6475,10 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, */ if (!s->gotit) s->curr_prompt = 0; + } else if (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) { + /* FIXME: perhaps we should support this? */ + bombout(("PASSWD_CHANGEREQ not yet supported")); + crStopV; } else if (pktin->type != SSH2_MSG_USERAUTH_FAILURE) { bombout(("Strange packet received during authentication: type %d", pktin->type)); @@ -5855,19 +6602,11 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, s->p = s->response + 5; s->nkeys = GET_32BIT(s->p); s->p += 4; - { - char buf[64]; - sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys); - logevent(buf); - } + logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys); for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) { void *vret; - { - char buf[64]; - sprintf(buf, "Trying Pageant key #%d", s->keyi); - logevent(buf); - } + logeventf(ssh, "Trying Pageant key #%d", s->keyi); s->pklen = GET_32BIT(s->p); s->p += 4; if (s->publickey_blob && @@ -6056,10 +6795,10 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, } } - if (!s->method && s->can_keyb_inter && !s->tried_keyb_inter) { + if (!s->method && s->can_keyb_inter && !s->kbd_inter_refused && + !s->kbd_inter_running) { s->method = AUTH_KEYBOARD_INTERACTIVE; s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE; - s->tried_keyb_inter = TRUE; ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK; ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER; @@ -6078,9 +6817,11 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, s->gotit = TRUE; logevent("Keyboard-interactive authentication refused"); s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET; + s->kbd_inter_refused = TRUE; /* don't try it again */ continue; } + c_write_str(ssh, "Using keyboard-interactive authentication.\r\n"); s->kbd_inter_running = TRUE; s->curr_prompt = 0; } @@ -6088,7 +6829,6 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, if (s->kbd_inter_running) { s->method = AUTH_KEYBOARD_INTERACTIVE; s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE; - s->tried_keyb_inter = TRUE; ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK; ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER; @@ -6174,6 +6914,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, logevent("Unable to authenticate"); connection_fatal(ssh->frontend, "Unable to authenticate"); + ssh->close_expected = TRUE; ssh_closing((Plug)ssh, NULL, 0, 0); crStopV; } @@ -6276,20 +7017,16 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, } } else if (s->method == AUTH_PASSWORD) { /* - * We send the password packet lumped tightly together with - * an SSH_MSG_IGNORE packet. The IGNORE packet contains a - * string long enough to make the total length of the two - * packets constant. This should ensure that a passive - * listener doing traffic analyis can't work out the length - * of the password. + * We pad out the password packet to 256 bytes to make + * it harder for an attacker to find the length of the + * user's password. * - * For this to work, we need an assumption about the - * maximum length of the password packet. I think 256 is - * pretty conservative. Anyone using a password longer than - * that probably doesn't have much to worry about from + * Anyone using a password longer than 256 bytes + * probably doesn't have much to worry about from * people who find out how long their password is! */ s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST); + s->pktout->forcepad = 256; ssh2_pkt_addstring(s->pktout, s->username); ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */ ssh2_pkt_addstring(s->pktout, "password"); @@ -6298,46 +7035,13 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, ssh2_pkt_addstring(s->pktout, s->password); memset(s->password, 0, sizeof(s->password)); end_log_omission(ssh, s->pktout); - ssh2_pkt_defer(ssh, s->pktout); - /* - * We'll include a string that's an exact multiple of the - * cipher block size. If the cipher is NULL for some - * reason, we don't do this trick at all because we gain - * nothing by it. - */ - if (ssh->cscipher) { - int stringlen, i; - - stringlen = (256 - ssh->deferred_len); - stringlen += ssh->cscipher->blksize - 1; - stringlen -= (stringlen % ssh->cscipher->blksize); - if (ssh->cscomp) { - /* - * Temporarily disable actual compression, - * so we can guarantee to get this string - * exactly the length we want it. The - * compression-disabling routine should - * return an integer indicating how many - * bytes we should adjust our string length - * by. - */ - stringlen -= - ssh->cscomp->disable_compression(ssh->cs_comp_ctx); - } - s->pktout = ssh2_pkt_init(SSH2_MSG_IGNORE); - ssh2_pkt_addstring_start(s->pktout); - for (i = 0; i < stringlen; i++) { - char c = (char) random_byte(); - ssh2_pkt_addstring_data(s->pktout, &c, 1); - } - ssh2_pkt_defer(ssh, s->pktout); - } - ssh_pkt_defersend(ssh); + ssh2_pkt_send(ssh, s->pktout); logevent("Sent password"); s->type = AUTH_TYPE_PASSWORD; } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) { if (s->curr_prompt == 0) { s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE); + s->pktout->forcepad = 256; ssh2_pkt_adduint32(s->pktout, s->num_prompts); } if (s->need_pw) { /* only add pw if we just got one! */ @@ -6372,6 +7076,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, " methods available"); ssh2_pkt_addstring(s->pktout, "en"); /* language tag */ ssh2_pkt_send_noqueue(ssh, s->pktout); + ssh->close_expected = TRUE; ssh_closing((Plug)ssh, NULL, 0, 0); crStopV; } @@ -6407,7 +7112,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid); ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE; ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */ - ssh2_pkt_adduint32(s->pktout, 0x4000UL); /* our max pkt size */ + ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */ ssh2_pkt_send(ssh, s->pktout); crWaitUntilV(pktin); if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) { @@ -6420,6 +7125,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, crStopV; } ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin); + ssh->mainchan->halfopen = FALSE; ssh->mainchan->type = CHAN_MAINSESSION; ssh->mainchan->closes = 0; ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin); @@ -6486,163 +7192,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, /* * Enable port forwardings. */ - { - char type; - int n; - int sport,dport,sserv,dserv; - char sports[256], dports[256], saddr[256], host[256]; - - ssh->rportfwds = newtree234(ssh_rportcmp_ssh2); - /* Add port forwardings. */ - ssh->portfwd_strptr = ssh->cfg.portfwd; - while (*ssh->portfwd_strptr) { - type = *ssh->portfwd_strptr++; - saddr[0] = '\0'; - n = 0; - while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') { - if (*ssh->portfwd_strptr == ':') { - /* - * We've seen a colon in the middle of the - * source port number. This means that - * everything we've seen until now is the - * source _address_, so we'll move it into - * saddr and start sports from the beginning - * again. - */ - ssh->portfwd_strptr++; - sports[n] = '\0'; - strcpy(saddr, sports); - n = 0; - } - if (n < 255) sports[n++] = *ssh->portfwd_strptr++; - } - sports[n] = 0; - if (type != 'D') { - if (*ssh->portfwd_strptr == '\t') - ssh->portfwd_strptr++; - n = 0; - while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') { - if (n < 255) host[n++] = *ssh->portfwd_strptr++; - } - host[n] = 0; - if (*ssh->portfwd_strptr == ':') - ssh->portfwd_strptr++; - n = 0; - while (*ssh->portfwd_strptr) { - if (n < 255) dports[n++] = *ssh->portfwd_strptr++; - } - dports[n] = 0; - ssh->portfwd_strptr++; - dport = atoi(dports); - dserv = 0; - if (dport == 0) { - dserv = 1; - dport = net_service_lookup(dports); - if (!dport) { - logeventf(ssh, "Service lookup failed for destination" - " port \"%s\"", dports); - } - } - } else { - while (*ssh->portfwd_strptr) ssh->portfwd_strptr++; - dport = dserv = -1; - ssh->portfwd_strptr++; /* eat the NUL and move to next one */ - } - sport = atoi(sports); - sserv = 0; - if (sport == 0) { - sserv = 1; - sport = net_service_lookup(sports); - if (!sport) { - logeventf(ssh, "Service lookup failed for source" - " port \"%s\"", sports); - } - } - if (sport && dport) { - /* Set up a description of the source port. */ - static char *sportdesc; - sportdesc = dupprintf("%.*s%.*s%.*s%.*s%d%.*s", - (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL, - (int)(*saddr?1:0), ":", - (int)(sserv ? strlen(sports) : 0), sports, - sserv, "(", sport, sserv, ")"); - if (type == 'L') { - /* Verbose description of the destination port */ - char *dportdesc = dupprintf("%s:%.*s%.*s%d%.*s", - host, - (int)(dserv ? strlen(dports) : 0), dports, - dserv, "(", dport, dserv, ")"); - const char *err = pfd_addforward(host, dport, - *saddr ? saddr : NULL, - sport, ssh, &ssh->cfg); - if (err) { - logeventf(ssh, "Local port %s forward to %s" - " failed: %s", sportdesc, dportdesc, err); - } else { - logeventf(ssh, "Local port %s forwarding to %s", - sportdesc, dportdesc); - } - sfree(dportdesc); - } else if (type == 'D') { - const char *err = pfd_addforward(NULL, -1, - *saddr ? saddr : NULL, - sport, ssh, &ssh->cfg); - if (err) { - logeventf(ssh, "Local port %s SOCKS dynamic forward" - " setup failed: %s", sportdesc, err); - } else { - logeventf(ssh, "Local port %s doing SOCKS" - " dynamic forwarding", sportdesc); - } - } else { - struct ssh_rportfwd *pf; - pf = snew(struct ssh_rportfwd); - strcpy(pf->dhost, host); - pf->dport = dport; - pf->sport = sport; - if (add234(ssh->rportfwds, pf) != pf) { - logeventf(ssh, "Duplicate remote port forwarding" - " to %s:%d", host, dport); - sfree(pf); - } else { - logeventf(ssh, "Requesting remote port %s" - " forward to %s:%.*s%.*s%d%.*s", - sportdesc, - host, - (int)(dserv ? strlen(dports) : 0), dports, - dserv, "(", dport, dserv, ")"); - s->pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST); - ssh2_pkt_addstring(s->pktout, "tcpip-forward"); - ssh2_pkt_addbool(s->pktout, 1);/* want reply */ - if (*saddr) { - ssh2_pkt_addstring(s->pktout, saddr); - } else if (ssh->cfg.rport_acceptall) { - ssh2_pkt_addstring(s->pktout, "0.0.0.0"); - } else { - ssh2_pkt_addstring(s->pktout, "127.0.0.1"); - } - ssh2_pkt_adduint32(s->pktout, sport); - ssh2_pkt_send(ssh, s->pktout); - - crWaitUntilV(pktin); - - if (pktin->type != SSH2_MSG_REQUEST_SUCCESS) { - if (pktin->type != SSH2_MSG_REQUEST_FAILURE) { - bombout(("Unexpected response to port " - "forwarding request: packet type %d", - pktin->type)); - crStopV; - } - logevent("Server refused this port forwarding"); - } else { - logevent("Remote port forwarding enabled"); - } - } - } - sfree(sportdesc); - } - } - } + ssh_setup_portfwd(ssh, &ssh->cfg); /* * Potentially enable agent forwarding. @@ -6796,6 +7346,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, } else { subsys = ssh->cfg.ssh_subsys; cmd = ssh->cfg.remote_cmd_ptr; + if (!cmd) cmd = ssh->cfg.remote_cmd; } s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); @@ -6880,30 +7431,8 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, /* * Try to send data on all channels if we can. */ - for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) { - int bufsize; - if (c->closes) - continue; /* don't send on closing channels */ - bufsize = ssh2_try_send(c); - if (bufsize == 0) { - switch (c->type) { - case CHAN_MAINSESSION: - /* stdin need not receive an unthrottle - * notification since it will be polled */ - break; - case CHAN_X11: - x11_unthrottle(c->u.x11.s); - break; - case CHAN_AGENT: - /* agent sockets are request/response and need no - * buffer management */ - break; - case CHAN_SOCKDATA: - pfd_unthrottle(c->u.pfd.s); - break; - } - } - } + for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) + ssh2_try_send_and_unthrottle(c); } } @@ -6911,9 +7440,9 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, } /* - * Handlers for SSH2 messages that might arrive at any moment. + * Handlers for SSH-2 messages that might arrive at any moment. */ -void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin) +static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin) { /* log reason code in disconnect message */ char *buf, *msg; @@ -6942,10 +7471,10 @@ void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin) sfree(buf); } -void ssh2_msg_debug(Ssh ssh, struct Packet *pktin) +static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin) { /* log the debug message */ - char *buf, *msg; + char *msg; int msglen; int always_display; @@ -6953,12 +7482,10 @@ void ssh2_msg_debug(Ssh ssh, struct Packet *pktin) always_display = ssh2_pkt_getbool(pktin); ssh_pkt_getstring(pktin, &msg, &msglen); - buf = dupprintf("Remote debug message: %.*s", msglen, msg); - logevent(buf); - sfree(buf); + logeventf(ssh, "Remote debug message: %.*s", msglen, msg); } -void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin) +static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin) { struct Packet *pktout; pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED); @@ -6971,7 +7498,7 @@ void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin) } /* - * Handle the top-level SSH2 protocol. + * Handle the top-level SSH-2 protocol. */ static void ssh2_protocol_setup(Ssh ssh) { @@ -7025,7 +7552,7 @@ static void ssh2_protocol_setup(Ssh ssh) * These special message types we install handlers for. */ ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect; - ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with ssh1 */ + ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */ ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug; } @@ -7033,25 +7560,28 @@ static void ssh2_timer(void *ctx, long now) { Ssh ssh = (Ssh)ctx; - if (!ssh->kex_in_progress && + if (ssh->state == SSH_STATE_CLOSED) + return; + + if (!ssh->kex_in_progress && ssh->cfg.ssh_rekey_time != 0 && now - ssh->next_rekey >= 0) { - do_ssh2_transport(ssh, "Initiating key re-exchange (timeout)", - -1, NULL); + do_ssh2_transport(ssh, "timeout", -1, NULL); } } -static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, +static void ssh2_protocol(Ssh ssh, void *vin, int inlen, struct Packet *pktin) { + unsigned char *in = (unsigned char *)vin; if (ssh->state == SSH_STATE_CLOSED) return; if (pktin) { ssh->incoming_data_size += pktin->encrypted_len; if (!ssh->kex_in_progress && - ssh->incoming_data_size > MAX_DATA_BEFORE_REKEY) - do_ssh2_transport(ssh, "Initiating key re-exchange " - "(too much data received)", -1, NULL); + ssh->max_data_size != 0 && + ssh->incoming_data_size > ssh->max_data_size) + do_ssh2_transport(ssh, "too much data received", -1, NULL); } if (pktin && ssh->packet_dispatch[pktin->type]) { @@ -7110,6 +7640,7 @@ static const char *ssh_init(void *frontend_handle, void **backend_handle, ssh->kex_ctx = NULL; ssh->hostkey = NULL; ssh->exitcode = -1; + ssh->close_expected = FALSE; ssh->state = SSH_STATE_PREPACKET; ssh->size_needed = FALSE; ssh->eof_needed = FALSE; @@ -7141,6 +7672,10 @@ static const char *ssh_init(void *frontend_handle, void **backend_handle, ssh->queue = NULL; ssh->queuelen = ssh->queuesize = 0; ssh->queueing = FALSE; + ssh->qhead = ssh->qtail = NULL; + ssh->deferred_rekey_reason = NULL; + bufchain_init(&ssh->queued_incoming_data); + ssh->frozen = FALSE; *backend_handle = ssh; @@ -7155,6 +7690,7 @@ static const char *ssh_init(void *frontend_handle, void **backend_handle, ssh->channels = NULL; ssh->rportfwds = NULL; + ssh->portfwds = NULL; ssh->send_ok = 0; ssh->editing = 0; @@ -7171,6 +7707,7 @@ static const char *ssh_init(void *frontend_handle, void **backend_handle, ssh->incoming_data_size = ssh->outgoing_data_size = ssh->deferred_data_size = 0L; + ssh->max_data_size = parse_blocksize(ssh->cfg.ssh_rekey_data); ssh->kex_in_progress = FALSE; p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive); @@ -7218,6 +7755,13 @@ static void ssh_free(void *handle) ssh_free_packet(ssh->queue[ssh->queuelen]); sfree(ssh->queue); + while (ssh->qhead) { + struct queued_handler *qh = ssh->qhead; + ssh->qhead = qh->next; + sfree(ssh->qhead); + } + ssh->qhead = ssh->qtail = NULL; + if (ssh->channels) { while ((c = delpos234(ssh->channels, 0)) != NULL) { switch (c->type) { @@ -7233,12 +7777,14 @@ static void ssh_free(void *handle) 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) @@ -7252,29 +7798,70 @@ static void ssh_free(void *handle) ssh->crcda_ctx = NULL; } if (ssh->s) - ssh_do_close(ssh); + ssh_do_close(ssh, TRUE); expire_timer_context(ssh); - sfree(ssh); if (ssh->pinger) pinger_free(ssh->pinger); + bufchain_clear(&ssh->queued_incoming_data); + sfree(ssh); random_unref(); } /* * Reconfigure the SSH backend. - * - * Currently, this function does nothing very useful. In future, - * however, we could do some handy things with it. For example, we - * could make the port forwarding configurer active in the Change - * Settings box, and this routine could close down existing - * forwardings and open up new ones in response to changes. */ static void ssh_reconfig(void *handle, Config *cfg) { Ssh ssh = (Ssh) handle; + char *rekeying = NULL, rekey_mandatory = FALSE; + unsigned long old_max_data_size; + pinger_reconfig(ssh->pinger, &ssh->cfg, cfg); + ssh_setup_portfwd(ssh, cfg); + + if (ssh->cfg.ssh_rekey_time != cfg->ssh_rekey_time && + cfg->ssh_rekey_time != 0) { + long new_next = ssh->last_rekey + cfg->ssh_rekey_time*60*TICKSPERSEC; + long now = GETTICKCOUNT(); + + if (new_next - now < 0) { + rekeying = "timeout shortened"; + } else { + ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh); + } + } + + old_max_data_size = ssh->max_data_size; + ssh->max_data_size = parse_blocksize(cfg->ssh_rekey_data); + if (old_max_data_size != ssh->max_data_size && + ssh->max_data_size != 0) { + if (ssh->outgoing_data_size > ssh->max_data_size || + ssh->incoming_data_size > ssh->max_data_size) + rekeying = "data limit lowered"; + } + + if (ssh->cfg.compression != cfg->compression) { + rekeying = "compression setting changed"; + rekey_mandatory = TRUE; + } + + if (ssh->cfg.ssh2_des_cbc != cfg->ssh2_des_cbc || + memcmp(ssh->cfg.ssh_cipherlist, cfg->ssh_cipherlist, + sizeof(ssh->cfg.ssh_cipherlist))) { + rekeying = "cipher settings changed"; + rekey_mandatory = TRUE; + } + ssh->cfg = *cfg; /* STRUCTURE COPY */ + + if (rekeying) { + if (!ssh->kex_in_progress) { + do_ssh2_transport(ssh, rekeying, -1, NULL); + } else if (rekey_mandatory) { + ssh->deferred_rekey_reason = rekeying; + } + } } /* @@ -7372,14 +7959,17 @@ static void ssh_size(void *handle, int width, int height) */ static const struct telnet_special *ssh_get_specials(void *handle) { - static const struct telnet_special ignore_special[] = { + static const struct telnet_special ssh1_ignore_special[] = { + {"IGNORE message", TS_NOP} + }; + static const struct telnet_special ssh2_transport_specials[] = { {"IGNORE message", TS_NOP}, {"Repeat key exchange", TS_REKEY}, }; static const struct telnet_special ssh2_session_specials[] = { {NULL, TS_SEP}, {"Break", TS_BRK}, - /* These are the signal names defined by draft-ietf-secsh-connect-19. + /* These are the signal names defined by draft-ietf-secsh-connect-23. * They include all the ISO C signals, but are a subset of the POSIX * required signals. */ {"SIGINT (Interrupt)", TS_SIGINT}, @@ -7397,7 +7987,8 @@ static const struct telnet_special *ssh_get_specials(void *handle) static const struct telnet_special specials_end[] = { {NULL, TS_EXITMENU} }; - static struct telnet_special ssh_specials[lenof(ignore_special) + + /* XXX review this length for any changes: */ + static struct telnet_special ssh_specials[lenof(ssh2_transport_specials) + lenof(ssh2_session_specials) + lenof(specials_end)]; Ssh ssh = (Ssh) handle; @@ -7414,9 +8005,9 @@ static const struct telnet_special *ssh_get_specials(void *handle) * won't cope with it, since we wouldn't bother sending it if * asked anyway. */ if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) - ADD_SPECIALS(ignore_special); + ADD_SPECIALS(ssh1_ignore_special); } else if (ssh->version == 2) { - ADD_SPECIALS(ignore_special); + ADD_SPECIALS(ssh2_transport_specials); if (ssh->mainchan) ADD_SPECIALS(ssh2_session_specials); } /* else we're not ready yet */ @@ -7456,6 +8047,7 @@ static void ssh_special(void *handle, Telnet_Special code) struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF); ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid); ssh2_pkt_send(ssh, pktout); + ssh->send_ok = 0; /* now stop trying to read from stdin */ } logevent("Sent EOF message"); } else if (code == TS_PING || code == TS_NOP) { @@ -7471,14 +8063,13 @@ static void ssh_special(void *handle, Telnet_Special code) } } else if (code == TS_REKEY) { if (!ssh->kex_in_progress && ssh->version == 2) { - do_ssh2_transport(ssh, "Initiating key re-exchange at" - " user request", -1, NULL); + do_ssh2_transport(ssh, "at user request", -1, NULL); } } else if (code == TS_BRK) { if (ssh->state == SSH_STATE_CLOSED || ssh->state == SSH_STATE_PREPACKET) return; if (ssh->version == 1) { - logevent("Unable to send BREAK signal in SSH1"); + logevent("Unable to send BREAK signal in SSH-1"); } else if (ssh->mainchan) { pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST); ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid); @@ -7530,7 +8121,7 @@ void *new_sock_channel(void *handle, Socket s) c->ssh = ssh; if (c) { - c->remoteid = -1; /* to be set when open confirmed */ + c->halfopen = TRUE; c->localid = alloc_channel_id(ssh); c->closes = 0; c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */ @@ -7572,7 +8163,7 @@ void ssh_send_port_open(void *channel, char *hostname, int port, char *org) PKT_INT, c->localid, PKT_STR, hostname, PKT_INT, port, - //PKT_STR, , + /* PKT_STR, , */ PKT_END); } else { pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN); @@ -7580,7 +8171,7 @@ void ssh_send_port_open(void *channel, char *hostname, int port, char *org) ssh2_pkt_adduint32(pktout, c->localid); c->v.v2.locwindow = OUR_V2_WINSIZE; ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */ - ssh2_pkt_adduint32(pktout, 0x4000UL); /* our max pkt size */ + ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */ ssh2_pkt_addstring(pktout, hostname); ssh2_pkt_adduint32(pktout, port); /* @@ -7639,6 +8230,16 @@ static int ssh_return_exitcode(void *handle) } /* + * cfg_info for SSH is the currently running version of the + * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.) + */ +static int ssh_cfg_info(void *handle) +{ + Ssh ssh = (Ssh) handle; + return ssh->version; +} + +/* * Gross hack: pscp will try to start SFTP but fall back to scp1 if * that fails. This variable is the means by which scp.c can reach * into the SSH code and find out which one it got. @@ -7665,5 +8266,6 @@ Backend ssh_backend = { ssh_provide_ldisc, ssh_provide_logctx, ssh_unthrottle, + ssh_cfg_info, 22 };