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e0a76971cc
putty-source/sshcommon.c
Simon Tatham e0a76971cc New array-growing macros: sgrowarray and sgrowarrayn. 
The idea of these is that they centralise the common idiom along the
lines of

   if (logical_array_len >= physical_array_size) {
       physical_array_size = logical_array_len * 5 / 4 + 256;
       array = sresize(array, physical_array_size, ElementType);
   }

which happens at a zillion call sites throughout this code base, with
different random choices of the geometric factor and additive
constant, sometimes forgetting them completely, and generally doing a
lot of repeated work.

The new macro sgrowarray(array,size,n) has the semantics: here are the
array pointer and its physical size for you to modify, now please
ensure that the nth element exists, so I can write into it. And
sgrowarrayn(array,size,n,m) is the same except that it ensures that
the array has size at least n+m (so sgrowarray is just the special
case where m=1).

Now that this is a single centralised implementation that will be used
everywhere, I've also gone to more effort in the implementation, with
careful overflow checks that would have been painful to put at all the
previous call sites.

This commit also switches over every use of sresize(), apart from a
few where I really didn't think it would gain anything. A consequence
of that is that a lot of array-size variables have to have their types
changed to size_t, because the macros require that (they address-take
the size to pass to the underlying function).
2019-02-28 20:15:38 +00:00

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/*
* Supporting routines used in common by all the various components of
* the SSH system.
*/
#include <assert.h>
#include <stdlib.h>
#include "putty.h"
#include "mpint.h"
#include "ssh.h"
#include "sshbpp.h"
#include "sshppl.h"
#include "sshchan.h"
/* ----------------------------------------------------------------------
* Implementation of PacketQueue.
*/
static void pq_ensure_unlinked(PacketQueueNode *node)
{
if (node->on_free_queue) {
node->next->prev = node->prev;
node->prev->next = node->next;
} else {
assert(!node->next);
assert(!node->prev);
}
}
void pq_base_push(PacketQueueBase *pqb, PacketQueueNode *node)
{
pq_ensure_unlinked(node);
node->next = &pqb->end;
node->prev = pqb->end.prev;
node->next->prev = node;
node->prev->next = node;
if (pqb->ic)
queue_idempotent_callback(pqb->ic);
}
void pq_base_push_front(PacketQueueBase *pqb, PacketQueueNode *node)
{
pq_ensure_unlinked(node);
node->prev = &pqb->end;
node->next = pqb->end.next;
node->next->prev = node;
node->prev->next = node;
if (pqb->ic)
queue_idempotent_callback(pqb->ic);
}
static PacketQueueNode pktin_freeq_head = {
&pktin_freeq_head, &pktin_freeq_head, true
};
static void pktin_free_queue_callback(void *vctx)
{
while (pktin_freeq_head.next != &pktin_freeq_head) {
PacketQueueNode *node = pktin_freeq_head.next;
PktIn *pktin = container_of(node, PktIn, qnode);
pktin_freeq_head.next = node->next;
sfree(pktin);
}
pktin_freeq_head.prev = &pktin_freeq_head;
}
static IdempotentCallback ic_pktin_free = {
pktin_free_queue_callback, NULL, false
};
static PktIn *pq_in_after(PacketQueueBase *pqb,
PacketQueueNode *prev, bool pop)
{
PacketQueueNode *node = prev->next;
if (node == &pqb->end)
return NULL;
if (pop) {
node->next->prev = node->prev;
node->prev->next = node->next;
node->prev = pktin_freeq_head.prev;
node->next = &pktin_freeq_head;
node->next->prev = node;
node->prev->next = node;
node->on_free_queue = true;
queue_idempotent_callback(&ic_pktin_free);
}
return container_of(node, PktIn, qnode);
}
static PktOut *pq_out_after(PacketQueueBase *pqb,
PacketQueueNode *prev, bool pop)
{
PacketQueueNode *node = prev->next;
if (node == &pqb->end)
return NULL;
if (pop) {
node->next->prev = node->prev;
node->prev->next = node->next;
node->prev = node->next = NULL;
}
return container_of(node, PktOut, qnode);
}
void pq_in_init(PktInQueue *pq)
{
pq->pqb.ic = NULL;
pq->pqb.end.next = pq->pqb.end.prev = &pq->pqb.end;
pq->after = pq_in_after;
}
void pq_out_init(PktOutQueue *pq)
{
pq->pqb.ic = NULL;
pq->pqb.end.next = pq->pqb.end.prev = &pq->pqb.end;
pq->after = pq_out_after;
}
void pq_in_clear(PktInQueue *pq)
{
PktIn *pkt;
pq->pqb.ic = NULL;
while ((pkt = pq_pop(pq)) != NULL) {
/* No need to actually free these packets: pq_pop on a
* PktInQueue will automatically move them to the free
* queue. */
}
}
void pq_out_clear(PktOutQueue *pq)
{
PktOut *pkt;
pq->pqb.ic = NULL;
while ((pkt = pq_pop(pq)) != NULL)
ssh_free_pktout(pkt);
}
/*
* Concatenate the contents of the two queues q1 and q2, and leave the
* result in qdest. qdest must be either empty, or one of the input
* queues.
*/
void pq_base_concatenate(PacketQueueBase *qdest,
PacketQueueBase *q1, PacketQueueBase *q2)
{
struct PacketQueueNode *head1, *tail1, *head2, *tail2;
/*
* Extract the contents from both input queues, and empty them.
*/
head1 = (q1->end.next == &q1->end ? NULL : q1->end.next);
tail1 = (q1->end.prev == &q1->end ? NULL : q1->end.prev);
head2 = (q2->end.next == &q2->end ? NULL : q2->end.next);
tail2 = (q2->end.prev == &q2->end ? NULL : q2->end.prev);
q1->end.next = q1->end.prev = &q1->end;
q2->end.next = q2->end.prev = &q2->end;
/*
* Link the two lists together, handling the case where one or
* both is empty.
*/
if (tail1)
tail1->next = head2;
else
head1 = head2;
if (head2)
head2->prev = tail1;
else
tail2 = tail1;
/*
* Check the destination queue is currently empty. (If it was one
* of the input queues, then it will be, because we emptied both
* of those just a moment ago.)
*/
assert(qdest->end.next == &qdest->end);
assert(qdest->end.prev == &qdest->end);
/*
* If our concatenated list has anything in it, then put it in
* dest.
*/
if (!head1) {
assert(!tail2);
} else {
assert(tail2);
qdest->end.next = head1;
qdest->end.prev = tail2;
head1->prev = &qdest->end;
tail2->next = &qdest->end;
if (qdest->ic)
queue_idempotent_callback(qdest->ic);
}
}
/* ----------------------------------------------------------------------
* Low-level functions for the packet structures themselves.
*/
static void ssh_pkt_BinarySink_write(BinarySink *bs,
const void *data, size_t len);
PktOut *ssh_new_packet(void)
{
PktOut *pkt = snew(PktOut);
BinarySink_INIT(pkt, ssh_pkt_BinarySink_write);
pkt->data = NULL;
pkt->length = 0;
pkt->maxlen = 0;
pkt->downstream_id = 0;
pkt->additional_log_text = NULL;
pkt->qnode.next = pkt->qnode.prev = NULL;
pkt->qnode.on_free_queue = false;
return pkt;
}
static void ssh_pkt_adddata(PktOut *pkt, const void *data, int len)
{
sgrowarrayn(pkt->data, pkt->maxlen, pkt->length, len);
memcpy(pkt->data + pkt->length, data, len);
pkt->length += len;
}
static void ssh_pkt_BinarySink_write(BinarySink *bs,
const void *data, size_t len)
{
PktOut *pkt = BinarySink_DOWNCAST(bs, PktOut);
ssh_pkt_adddata(pkt, data, len);
}
void ssh_free_pktout(PktOut *pkt)
{
sfree(pkt->data);
sfree(pkt);
}
/* ----------------------------------------------------------------------
* Implement zombiechan_new() and its trivial vtable.
*/
static void zombiechan_free(Channel *chan);
static size_t zombiechan_send(
Channel *chan, bool is_stderr, const void *, size_t);
static void zombiechan_set_input_wanted(Channel *chan, bool wanted);
static void zombiechan_do_nothing(Channel *chan);
static void zombiechan_open_failure(Channel *chan, const char *);
static bool zombiechan_want_close(Channel *chan, bool sent_eof, bool rcvd_eof);
static char *zombiechan_log_close_msg(Channel *chan) { return NULL; }
static const struct ChannelVtable zombiechan_channelvt = {
zombiechan_free,
zombiechan_do_nothing, /* open_confirmation */
zombiechan_open_failure,
zombiechan_send,
zombiechan_do_nothing, /* send_eof */
zombiechan_set_input_wanted,
zombiechan_log_close_msg,
zombiechan_want_close,
chan_no_exit_status,
chan_no_exit_signal,
chan_no_exit_signal_numeric,
chan_no_run_shell,
chan_no_run_command,
chan_no_run_subsystem,
chan_no_enable_x11_forwarding,
chan_no_enable_agent_forwarding,
chan_no_allocate_pty,
chan_no_set_env,
chan_no_send_break,
chan_no_send_signal,
chan_no_change_window_size,
chan_no_request_response,
};
Channel *zombiechan_new(void)
{
Channel *chan = snew(Channel);
chan->vt = &zombiechan_channelvt;
chan->initial_fixed_window_size = 0;
return chan;
}
static void zombiechan_free(Channel *chan)
{
assert(chan->vt == &zombiechan_channelvt);
sfree(chan);
}
static void zombiechan_do_nothing(Channel *chan)
{
assert(chan->vt == &zombiechan_channelvt);
}
static void zombiechan_open_failure(Channel *chan, const char *errtext)
{
assert(chan->vt == &zombiechan_channelvt);
}
static size_t zombiechan_send(Channel *chan, bool is_stderr,
const void *data, size_t length)
{
assert(chan->vt == &zombiechan_channelvt);
return 0;
}
static void zombiechan_set_input_wanted(Channel *chan, bool enable)
{
assert(chan->vt == &zombiechan_channelvt);
}
static bool zombiechan_want_close(Channel *chan, bool sent_eof, bool rcvd_eof)
{
return true;
}
/* ----------------------------------------------------------------------
* Centralised standard methods for other channel implementations to
* borrow.
*/
void chan_remotely_opened_confirmation(Channel *chan)
{
unreachable("this channel type should never receive OPEN_CONFIRMATION");
}
void chan_remotely_opened_failure(Channel *chan, const char *errtext)
{
unreachable("this channel type should never receive OPEN_FAILURE");
}
bool chan_default_want_close(
Channel *chan, bool sent_local_eof, bool rcvd_remote_eof)
{
/*
* Default close policy: we start initiating the CHANNEL_CLOSE
* procedure as soon as both sides of the channel have seen EOF.
*/
return sent_local_eof && rcvd_remote_eof;
}
bool chan_no_exit_status(Channel *chan, int status)
{
return false;
}
bool chan_no_exit_signal(
Channel *chan, ptrlen signame, bool core_dumped, ptrlen msg)
{
return false;
}
bool chan_no_exit_signal_numeric(
Channel *chan, int signum, bool core_dumped, ptrlen msg)
{
return false;
}
bool chan_no_run_shell(Channel *chan)
{
return false;
}
bool chan_no_run_command(Channel *chan, ptrlen command)
{
return false;
}
bool chan_no_run_subsystem(Channel *chan, ptrlen subsys)
{
return false;
}
bool chan_no_enable_x11_forwarding(
Channel *chan, bool oneshot, ptrlen authproto, ptrlen authdata,
unsigned screen_number)
{
return false;
}
bool chan_no_enable_agent_forwarding(Channel *chan)
{
return false;
}
bool chan_no_allocate_pty(
Channel *chan, ptrlen termtype, unsigned width, unsigned height,
unsigned pixwidth, unsigned pixheight, struct ssh_ttymodes modes)
{
return false;
}
bool chan_no_set_env(Channel *chan, ptrlen var, ptrlen value)
{
return false;
}
bool chan_no_send_break(Channel *chan, unsigned length)
{
return false;
}
bool chan_no_send_signal(Channel *chan, ptrlen signame)
{
return false;
}
bool chan_no_change_window_size(
Channel *chan, unsigned width, unsigned height,
unsigned pixwidth, unsigned pixheight)
{
return false;
}
void chan_no_request_response(Channel *chan, bool success)
{
unreachable("this channel type should never send a want-reply request");
}
/* ----------------------------------------------------------------------
* Common routines for handling SSH tty modes.
*/
static unsigned real_ttymode_opcode(unsigned our_opcode, int ssh_version)
{
switch (our_opcode) {
case TTYMODE_ISPEED:
return ssh_version == 1 ? TTYMODE_ISPEED_SSH1 : TTYMODE_ISPEED_SSH2;
case TTYMODE_OSPEED:
return ssh_version == 1 ? TTYMODE_OSPEED_SSH1 : TTYMODE_OSPEED_SSH2;
default:
return our_opcode;
}
}
static unsigned our_ttymode_opcode(unsigned real_opcode, int ssh_version)
{
if (ssh_version == 1) {
switch (real_opcode) {
case TTYMODE_ISPEED_SSH1:
return TTYMODE_ISPEED;
case TTYMODE_OSPEED_SSH1:
return TTYMODE_OSPEED;
default:
return real_opcode;
}
} else {
switch (real_opcode) {
case TTYMODE_ISPEED_SSH2:
return TTYMODE_ISPEED;
case TTYMODE_OSPEED_SSH2:
return TTYMODE_OSPEED;
default:
return real_opcode;
}
}
}
struct ssh_ttymodes get_ttymodes_from_conf(Seat *seat, Conf *conf)
{
struct ssh_ttymodes modes;
size_t i;
static const struct mode_name_type {
const char *mode;
int opcode;
enum { TYPE_CHAR, TYPE_BOOL } type;
} modes_names_types[] = {
#define TTYMODE_CHAR(name, val, index) { #name, val, TYPE_CHAR },
#define TTYMODE_FLAG(name, val, field, mask) { #name, val, TYPE_BOOL },
#include "sshttymodes.h"
#undef TTYMODE_CHAR
#undef TTYMODE_FLAG
};
memset(&modes, 0, sizeof(modes));
for (i = 0; i < lenof(modes_names_types); i++) {
const struct mode_name_type *mode = &modes_names_types[i];
const char *sval = conf_get_str_str(conf, CONF_ttymodes, mode->mode);
char *to_free = NULL;
if (!sval)
sval = "N"; /* just in case */
/*
* sval[0] can be
* - 'V', indicating that an explicit value follows it;
* - 'A', indicating that we should pass the value through from
* the local environment via get_ttymode; or
* - 'N', indicating that we should explicitly not send this
* mode.
*/
if (sval[0] == 'A') {
sval = to_free = seat_get_ttymode(seat, mode->mode);
} else if (sval[0] == 'V') {
sval++; /* skip the 'V' */
} else {
/* else 'N', or something from the future we don't understand */
continue;
}
if (sval) {
/*
* Parse the string representation of the tty mode
* into the integer value it will take on the wire.
*/
unsigned ival = 0;
switch (mode->type) {
case TYPE_CHAR:
if (*sval) {
char *next = NULL;
/* We know ctrlparse won't write to the string, so
* casting away const is ugly but allowable. */
ival = ctrlparse((char *)sval, &next);
if (!next)
ival = sval[0];
} else {
ival = 255; /* special value meaning "don't set" */
}
break;
case TYPE_BOOL:
if (stricmp(sval, "yes") == 0 ||
stricmp(sval, "on") == 0 ||
stricmp(sval, "true") == 0 ||
stricmp(sval, "+") == 0)
ival = 1; /* true */
else if (stricmp(sval, "no") == 0 ||
stricmp(sval, "off") == 0 ||
stricmp(sval, "false") == 0 ||
stricmp(sval, "-") == 0)
ival = 0; /* false */
else
ival = (atoi(sval) != 0);
break;
default:
unreachable("Bad mode->type");
}
modes.have_mode[mode->opcode] = true;
modes.mode_val[mode->opcode] = ival;
}
sfree(to_free);
}
{
unsigned ospeed, ispeed;
/* Unpick the terminal-speed config string. */
ospeed = ispeed = 38400; /* last-resort defaults */
sscanf(conf_get_str(conf, CONF_termspeed), "%u,%u", &ospeed, &ispeed);
/* Currently we unconditionally set these */
modes.have_mode[TTYMODE_ISPEED] = true;
modes.mode_val[TTYMODE_ISPEED] = ispeed;
modes.have_mode[TTYMODE_OSPEED] = true;
modes.mode_val[TTYMODE_OSPEED] = ospeed;
}
return modes;
}
struct ssh_ttymodes read_ttymodes_from_packet(
BinarySource *bs, int ssh_version)
{
struct ssh_ttymodes modes;
memset(&modes, 0, sizeof(modes));
while (1) {
unsigned real_opcode, our_opcode;
real_opcode = get_byte(bs);
if (real_opcode == TTYMODE_END_OF_LIST)
break;
if (real_opcode >= 160) {
/*
* RFC 4254 (and the SSH 1.5 spec): "Opcodes 160 to 255
* are not yet defined, and cause parsing to stop (they
* should only be used after any other data)."
*
* My interpretation of this is that if one of these
* opcodes appears, it's not a parse _error_, but it is
* something that we don't know how to parse even well
* enough to step over it to find the next opcode, so we
* stop parsing now and assume that the rest of the string
* is composed entirely of things we don't understand and
* (as usual for unsupported terminal modes) silently
* ignore.
*/
return modes;
}
our_opcode = our_ttymode_opcode(real_opcode, ssh_version);
assert(our_opcode < TTYMODE_LIMIT);
modes.have_mode[our_opcode] = true;
if (ssh_version == 1 && real_opcode >= 1 && real_opcode <= 127)
modes.mode_val[our_opcode] = get_byte(bs);
else
modes.mode_val[our_opcode] = get_uint32(bs);
}
return modes;
}
void write_ttymodes_to_packet(BinarySink *bs, int ssh_version,
struct ssh_ttymodes modes)
{
unsigned i;
for (i = 0; i < TTYMODE_LIMIT; i++) {
if (modes.have_mode[i]) {
unsigned val = modes.mode_val[i];
unsigned opcode = real_ttymode_opcode(i, ssh_version);
put_byte(bs, opcode);
if (ssh_version == 1 && opcode >= 1 && opcode <= 127)
put_byte(bs, val);
else
put_uint32(bs, val);
}
}
put_byte(bs, TTYMODE_END_OF_LIST);
}
/* ----------------------------------------------------------------------
* Routine for allocating a new channel ID, given a means of finding
* the index field in a given channel structure.
*/
unsigned alloc_channel_id_general(tree234 *channels, size_t localid_offset)
{
const unsigned CHANNEL_NUMBER_OFFSET = 256;
search234_state ss;
/*
* First-fit allocation of channel numbers: we always pick the
* lowest unused one.
*
* Every channel before that, and no channel after it, has an ID
* exactly equal to its tree index plus CHANNEL_NUMBER_OFFSET. So
* we can use the search234 system to identify the length of that
* initial sequence, in a single log-time pass down the channels
* tree.
*/
search234_start(&ss, channels);
while (ss.element) {
unsigned localid = *(unsigned *)((char *)ss.element + localid_offset);
if (localid == ss.index + CHANNEL_NUMBER_OFFSET)
search234_step(&ss, +1);
else
search234_step(&ss, -1);
}
/*
* Now ss.index gives exactly the number of channels in that
* initial sequence. So adding CHANNEL_NUMBER_OFFSET to it must
* give precisely the lowest unused channel number.
*/
return ss.index + CHANNEL_NUMBER_OFFSET;
}
/* ----------------------------------------------------------------------
* Functions for handling the comma-separated strings used to store
* lists of protocol identifiers in SSH-2.
*/
void add_to_commasep(strbuf *buf, const char *data)
{
if (buf->len > 0)
put_byte(buf, ',');
put_data(buf, data, strlen(data));
}
bool get_commasep_word(ptrlen *list, ptrlen *word)
{
const char *comma;
/*
* Discard empty list elements, should there be any, because we
* never want to return one as if it was a real string. (This
* introduces a mild tolerance of badly formatted data in lists we
* receive, but I think that's acceptable.)
*/
while (list->len > 0 && *(const char *)list->ptr == ',') {
list->ptr = (const char *)list->ptr + 1;
list->len--;
}
if (!list->len)
return false;
comma = memchr(list->ptr, ',', list->len);
if (!comma) {
*word = *list;
list->len = 0;
} else {
size_t wordlen = comma - (const char *)list->ptr;
word->ptr = list->ptr;
word->len = wordlen;
list->ptr = (const char *)list->ptr + wordlen + 1;
list->len -= wordlen + 1;
}
return true;
}
/* ----------------------------------------------------------------------
* Functions for translating SSH packet type codes into their symbolic
* string names.
*/
#define TRANSLATE_UNIVERSAL(y, name, value) \
if (type == value) return #name;
#define TRANSLATE_KEX(y, name, value, ctx) \
if (type == value && pkt_kctx == ctx) return #name;
#define TRANSLATE_AUTH(y, name, value, ctx) \
if (type == value && pkt_actx == ctx) return #name;
const char *ssh1_pkt_type(int type)
{
SSH1_MESSAGE_TYPES(TRANSLATE_UNIVERSAL, y);
return "unknown";
}
const char *ssh2_pkt_type(Pkt_KCtx pkt_kctx, Pkt_ACtx pkt_actx, int type)
{
SSH2_MESSAGE_TYPES(TRANSLATE_UNIVERSAL, TRANSLATE_KEX, TRANSLATE_AUTH, y);
return "unknown";
}
#undef TRANSLATE_UNIVERSAL
#undef TRANSLATE_KEX
#undef TRANSLATE_AUTH
/* ----------------------------------------------------------------------
* Common helper function for clients and implementations of
* PacketProtocolLayer.
*/
void ssh_ppl_replace(PacketProtocolLayer *old, PacketProtocolLayer *new)
{
new->bpp = old->bpp;
ssh_ppl_setup_queues(new, old->in_pq, old->out_pq);
new->selfptr = old->selfptr;
new->user_input = old->user_input;
new->seat = old->seat;
new->ssh = old->ssh;
*new->selfptr = new;
ssh_ppl_free(old);
/* The new layer might need to be the first one that sends a
* packet, so trigger a call to its main coroutine immediately. If
* it doesn't need to go first, the worst that will do is return
* straight away. */
queue_idempotent_callback(&new->ic_process_queue);
}
void ssh_ppl_free(PacketProtocolLayer *ppl)
{
delete_callbacks_for_context(ppl);
ppl->vt->free(ppl);
}
static void ssh_ppl_ic_process_queue_callback(void *context)
{
PacketProtocolLayer *ppl = (PacketProtocolLayer *)context;
ssh_ppl_process_queue(ppl);
}
void ssh_ppl_setup_queues(PacketProtocolLayer *ppl,
PktInQueue *inq, PktOutQueue *outq)
{
ppl->in_pq = inq;
ppl->out_pq = outq;
ppl->in_pq->pqb.ic = &ppl->ic_process_queue;
ppl->ic_process_queue.fn = ssh_ppl_ic_process_queue_callback;
ppl->ic_process_queue.ctx = ppl;
/* If there's already something on the input queue, it will want
* handling immediately. */
if (pq_peek(ppl->in_pq))
queue_idempotent_callback(&ppl->ic_process_queue);
}
void ssh_ppl_user_output_string_and_free(PacketProtocolLayer *ppl, char *text)
{
/* Messages sent via this function are from the SSH layer, not
* from the server-side process, so they always have the stderr
* flag set. */
seat_stderr(ppl->seat, text, strlen(text));
sfree(text);
}
/* ----------------------------------------------------------------------
* Common helper functions for clients and implementations of
* BinaryPacketProtocol.
*/
static void ssh_bpp_input_raw_data_callback(void *context)
{
BinaryPacketProtocol *bpp = (BinaryPacketProtocol *)context;
Ssh *ssh = bpp->ssh; /* in case bpp is about to get freed */
ssh_bpp_handle_input(bpp);
/* If we've now cleared enough backlog on the input connection, we
* may need to unfreeze it. */
ssh_conn_processed_data(ssh);
}
static void ssh_bpp_output_packet_callback(void *context)
{
BinaryPacketProtocol *bpp = (BinaryPacketProtocol *)context;
ssh_bpp_handle_output(bpp);
}
void ssh_bpp_common_setup(BinaryPacketProtocol *bpp)
{
pq_in_init(&bpp->in_pq);
pq_out_init(&bpp->out_pq);
bpp->input_eof = false;
bpp->ic_in_raw.fn = ssh_bpp_input_raw_data_callback;
bpp->ic_in_raw.ctx = bpp;
bpp->ic_out_pq.fn = ssh_bpp_output_packet_callback;
bpp->ic_out_pq.ctx = bpp;
bpp->out_pq.pqb.ic = &bpp->ic_out_pq;
}
void ssh_bpp_free(BinaryPacketProtocol *bpp)
{
delete_callbacks_for_context(bpp);
bpp->vt->free(bpp);
}
void ssh2_bpp_queue_disconnect(BinaryPacketProtocol *bpp,
const char *msg, int category)
{
PktOut *pkt = ssh_bpp_new_pktout(bpp, SSH2_MSG_DISCONNECT);
put_uint32(pkt, category);
put_stringz(pkt, msg);
put_stringz(pkt, "en"); /* language tag */
pq_push(&bpp->out_pq, pkt);
}
#define BITMAP_UNIVERSAL(y, name, value) \
| (value >= y && value < y+32 ? 1UL << (value-y) : 0)
#define BITMAP_CONDITIONAL(y, name, value, ctx) \
BITMAP_UNIVERSAL(y, name, value)
#define SSH2_BITMAP_WORD(y) \
(0 SSH2_MESSAGE_TYPES(BITMAP_UNIVERSAL, BITMAP_CONDITIONAL, \
BITMAP_CONDITIONAL, (32*y)))
bool ssh2_bpp_check_unimplemented(BinaryPacketProtocol *bpp, PktIn *pktin)
{
static const unsigned valid_bitmap[] = {
SSH2_BITMAP_WORD(0),
SSH2_BITMAP_WORD(1),
SSH2_BITMAP_WORD(2),
SSH2_BITMAP_WORD(3),
SSH2_BITMAP_WORD(4),
SSH2_BITMAP_WORD(5),
SSH2_BITMAP_WORD(6),
SSH2_BITMAP_WORD(7),
};
if (pktin->type < 0x100 &&
!((valid_bitmap[pktin->type >> 5] >> (pktin->type & 0x1F)) & 1)) {
PktOut *pkt = ssh_bpp_new_pktout(bpp, SSH2_MSG_UNIMPLEMENTED);
put_uint32(pkt, pktin->sequence);
pq_push(&bpp->out_pq, pkt);
return true;
}
return false;
}
#undef BITMAP_UNIVERSAL
#undef BITMAP_CONDITIONAL
#undef SSH1_BITMAP_WORD
/* ----------------------------------------------------------------------
* Function to check a host key against any manually configured in Conf.
*/
int verify_ssh_manual_host_key(
Conf *conf, const char *fingerprint, ssh_key *key)
{
if (!conf_get_str_nthstrkey(conf, CONF_ssh_manual_hostkeys, 0))
return -1; /* no manual keys configured */
if (fingerprint) {
/*
* The fingerprint string we've been given will have things
* like 'ssh-rsa 2048' at the front of it. Strip those off and
* narrow down to just the colon-separated hex block at the
* end of the string.
*/
const char *p = strrchr(fingerprint, ' ');
fingerprint = p ? p+1 : fingerprint;
/* Quick sanity checks, including making sure it's in lowercase */
assert(strlen(fingerprint) == 16*3 - 1);
assert(fingerprint[2] == ':');
assert(fingerprint[strspn(fingerprint, "0123456789abcdef:")] == 0);
if (conf_get_str_str_opt(conf, CONF_ssh_manual_hostkeys, fingerprint))
return 1; /* success */
}
if (key) {
/*
* Construct the base64-encoded public key blob and see if
* that's listed.
*/
strbuf *binblob;
char *base64blob;
int atoms, i;
binblob = strbuf_new();
ssh_key_public_blob(key, BinarySink_UPCAST(binblob));
atoms = (binblob->len + 2) / 3;
base64blob = snewn(atoms * 4 + 1, char);
for (i = 0; i < atoms; i++)
base64_encode_atom(binblob->u + 3*i,
binblob->len - 3*i, base64blob + 4*i);
base64blob[atoms * 4] = '\0';
strbuf_free(binblob);
if (conf_get_str_str_opt(conf, CONF_ssh_manual_hostkeys, base64blob)) {
sfree(base64blob);
return 1; /* success */
}
sfree(base64blob);
}
return 0;
}
/* ----------------------------------------------------------------------
* Common functions shared between SSH-1 layers.
*/
bool ssh1_common_get_specials(
PacketProtocolLayer *ppl, add_special_fn_t add_special, void *ctx)
{
/*
* Don't bother offering IGNORE if we've decided the remote
* won't cope with it, since we wouldn't bother sending it if
* asked anyway.
*/
if (!(ppl->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
add_special(ctx, "IGNORE message", SS_NOP, 0);
return true;
}
return false;
}
bool ssh1_common_filter_queue(PacketProtocolLayer *ppl)
{
PktIn *pktin;
ptrlen msg;
while ((pktin = pq_peek(ppl->in_pq)) != NULL) {
switch (pktin->type) {
case SSH1_MSG_DISCONNECT:
msg = get_string(pktin);
ssh_remote_error(ppl->ssh,
"Remote side sent disconnect message:\n\"%.*s\"",
PTRLEN_PRINTF(msg));
pq_pop(ppl->in_pq);
return true; /* indicate that we've been freed */
case SSH1_MSG_DEBUG:
msg = get_string(pktin);
ppl_logevent("Remote debug message: %.*s", PTRLEN_PRINTF(msg));
pq_pop(ppl->in_pq);
break;
case SSH1_MSG_IGNORE:
/* Do nothing, because we're ignoring it! Duhh. */
pq_pop(ppl->in_pq);
break;
default:
return false;
}
}
return false;
}
void ssh1_compute_session_id(
unsigned char *session_id, const unsigned char *cookie,
RSAKey *hostkey, RSAKey *servkey)
{
ssh_hash *hash = ssh_hash_new(&ssh_md5);
for (size_t i = (mp_get_nbits(hostkey->modulus) + 7) / 8; i-- ;)
put_byte(hash, mp_get_byte(hostkey->modulus, i));
for (size_t i = (mp_get_nbits(servkey->modulus) + 7) / 8; i-- ;)
put_byte(hash, mp_get_byte(servkey->modulus, i));
put_data(hash, cookie, 8);
ssh_hash_final(hash, session_id);
}
/* ----------------------------------------------------------------------
* Other miscellaneous utility functions.
*/
void free_rportfwd(struct ssh_rportfwd *rpf)
{
if (rpf) {
sfree(rpf->log_description);
sfree(rpf->shost);
sfree(rpf->dhost);
sfree(rpf);
}
}
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