*/
#include "includes.h"
-RCSID("$OpenBSD: packet.c,v 1.96 2002/06/23 21:10:02 deraadt Exp $");
+RCSID("$OpenBSD: packet.c,v 1.112 2003/09/23 20:17:11 markus Exp $");
+
+#include "openbsd-compat/sys-queue.h"
#include "xmalloc.h"
#include "buffer.h"
static int packet_compression = 0;
/* default maximum packet size */
-int max_packet_size = 32768;
+u_int max_packet_size = 32768;
/* Flag indicating whether this module has been initialized. */
static int initialized = 0;
/* Session key information for Encryption and MAC */
Newkeys *newkeys[MODE_MAX];
-static u_int32_t read_seqnr = 0;
-static u_int32_t send_seqnr = 0;
+static struct packet_state {
+ u_int32_t seqnr;
+ u_int32_t packets;
+ u_int64_t blocks;
+} p_read, p_send;
+
+static u_int64_t max_blocks_in, max_blocks_out;
+static u_int32_t rekey_limit;
/* Session key for protocol v1 */
static u_char ssh1_key[SSH_SESSION_KEY_LENGTH];
/* roundup current message to extra_pad bytes */
static u_char extra_pad = 0;
+struct packet {
+ TAILQ_ENTRY(packet) next;
+ u_char type;
+ Buffer payload;
+};
+TAILQ_HEAD(, packet) outgoing;
+
/*
* Sets the descriptors used for communication. Disables encryption until
* packet_set_encryption_key is called.
packet_set_connection(int fd_in, int fd_out)
{
Cipher *none = cipher_by_name("none");
+
if (none == NULL)
fatal("packet_set_connection: cannot load cipher 'none'");
connection_in = fd_in;
buffer_init(&output);
buffer_init(&outgoing_packet);
buffer_init(&incoming_packet);
+ TAILQ_INIT(&outgoing);
}
- /* Kludge: arrange the close function to be called from fatal(). */
- fatal_add_cleanup((void (*) (void *)) packet_close, NULL);
}
/* Returns 1 if remote host is connected via socket, 0 if not. */
cipher_set_keyiv(cc, dat);
}
int
-packet_get_ssh1_cipher()
+packet_get_ssh1_cipher(void)
{
return (cipher_get_number(receive_context.cipher));
}
-
-u_int32_t
-packet_get_seqnr(int mode)
+void
+packet_get_state(int mode, u_int32_t *seqnr, u_int64_t *blocks, u_int32_t *packets)
{
- return (mode == MODE_IN ? read_seqnr : send_seqnr);
+ struct packet_state *state;
+
+ state = (mode == MODE_IN) ? &p_read : &p_send;
+ *seqnr = state->seqnr;
+ *blocks = state->blocks;
+ *packets = state->packets;
}
void
-packet_set_seqnr(int mode, u_int32_t seqnr)
+packet_set_state(int mode, u_int32_t seqnr, u_int64_t blocks, u_int32_t packets)
{
- if (mode == MODE_IN)
- read_seqnr = seqnr;
- else if (mode == MODE_OUT)
- send_seqnr = seqnr;
- else
- fatal("packet_set_seqnr: bad mode %d", mode);
+ struct packet_state *state;
+
+ state = (mode == MODE_IN) ? &p_read : &p_send;
+ state->seqnr = seqnr;
+ state->blocks = blocks;
+ state->packets = packets;
}
/* returns 1 if connection is via ipv4 */
if (to.ss_family == AF_INET)
return 1;
#ifdef IPV4_IN_IPV6
- if (to.ss_family == AF_INET6 &&
+ if (to.ss_family == AF_INET6 &&
IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)&to)->sin6_addr))
return 1;
#endif
int number)
{
Cipher *cipher = cipher_by_number(number);
+
if (cipher == NULL)
fatal("packet_set_encryption_key: unknown cipher number %d", number);
if (keylen < 20)
packet_put_char(int value)
{
char ch = value;
+
buffer_append(&outgoing_packet, &ch, 1);
}
void
Mac *mac;
Comp *comp;
CipherContext *cc;
+ u_int64_t *max_blocks;
int encrypt;
- debug("newkeys: mode %d", mode);
+ debug2("set_newkeys: mode %d", mode);
if (mode == MODE_OUT) {
cc = &send_context;
encrypt = CIPHER_ENCRYPT;
+ p_send.packets = p_send.blocks = 0;
+ max_blocks = &max_blocks_out;
} else {
cc = &receive_context;
encrypt = CIPHER_DECRYPT;
+ p_read.packets = p_read.blocks = 0;
+ max_blocks = &max_blocks_in;
}
if (newkeys[mode] != NULL) {
- debug("newkeys: rekeying");
+ debug("set_newkeys: rekeying");
cipher_cleanup(cc);
enc = &newkeys[mode]->enc;
mac = &newkeys[mode]->mac;
buffer_compress_init_recv();
comp->enabled = 1;
}
+ /*
+ * The 2^(blocksize*2) limit is too expensive for 3DES,
+ * blowfish, etc, so enforce a 1GB limit for small blocksizes.
+ */
+ if (enc->block_size >= 16)
+ *max_blocks = (u_int64_t)1 << (enc->block_size*2);
+ else
+ *max_blocks = ((u_int64_t)1 << 30) / enc->block_size;
+ if (rekey_limit)
+ *max_blocks = MIN(*max_blocks, rekey_limit / enc->block_size);
}
/*
* Finalize packet in SSH2 format (compress, mac, encrypt, enqueue)
*/
static void
-packet_send2(void)
+packet_send2_wrapped(void)
{
u_char type, *cp, *macbuf = NULL;
u_char padlen, pad;
/* compute MAC over seqnr and packet(length fields, payload, padding) */
if (mac && mac->enabled) {
- macbuf = mac_compute(mac, send_seqnr,
+ macbuf = mac_compute(mac, p_send.seqnr,
buffer_ptr(&outgoing_packet),
buffer_len(&outgoing_packet));
- DBG(debug("done calc MAC out #%d", send_seqnr));
+ DBG(debug("done calc MAC out #%d", p_send.seqnr));
}
/* encrypt packet and append to output buffer. */
cp = buffer_append_space(&output, buffer_len(&outgoing_packet));
buffer_dump(&output);
#endif
/* increment sequence number for outgoing packets */
- if (++send_seqnr == 0)
- log("outgoing seqnr wraps around");
+ if (++p_send.seqnr == 0)
+ logit("outgoing seqnr wraps around");
+ if (++p_send.packets == 0)
+ if (!(datafellows & SSH_BUG_NOREKEY))
+ fatal("XXX too many packets with same key");
+ p_send.blocks += (packet_length + 4) / block_size;
buffer_clear(&outgoing_packet);
if (type == SSH2_MSG_NEWKEYS)
set_newkeys(MODE_OUT);
}
+static void
+packet_send2(void)
+{
+ static int rekeying = 0;
+ struct packet *p;
+ u_char type, *cp;
+
+ cp = buffer_ptr(&outgoing_packet);
+ type = cp[5];
+
+ /* during rekeying we can only send key exchange messages */
+ if (rekeying) {
+ if (!((type >= SSH2_MSG_TRANSPORT_MIN) &&
+ (type <= SSH2_MSG_TRANSPORT_MAX))) {
+ debug("enqueue packet: %u", type);
+ p = xmalloc(sizeof(*p));
+ p->type = type;
+ memcpy(&p->payload, &outgoing_packet, sizeof(Buffer));
+ buffer_init(&outgoing_packet);
+ TAILQ_INSERT_TAIL(&outgoing, p, next);
+ return;
+ }
+ }
+
+ /* rekeying starts with sending KEXINIT */
+ if (type == SSH2_MSG_KEXINIT)
+ rekeying = 1;
+
+ packet_send2_wrapped();
+
+ /* after a NEWKEYS message we can send the complete queue */
+ if (type == SSH2_MSG_NEWKEYS) {
+ rekeying = 0;
+ while ((p = TAILQ_FIRST(&outgoing))) {
+ type = p->type;
+ debug("dequeue packet: %u", type);
+ buffer_free(&outgoing_packet);
+ memcpy(&outgoing_packet, &p->payload,
+ sizeof(Buffer));
+ TAILQ_REMOVE(&outgoing, p, next);
+ xfree(p);
+ packet_send2_wrapped();
+ }
+ }
+}
+
void
packet_send(void)
{
/* Read data from the socket. */
len = read(connection_in, buf, sizeof(buf));
if (len == 0) {
- log("Connection closed by %.200s", get_remote_ipaddr());
- fatal_cleanup();
+ logit("Connection closed by %.200s", get_remote_ipaddr());
+ cleanup_exit(255);
}
if (len < 0)
fatal("Read from socket failed: %.100s", strerror(errno));
cp = buffer_ptr(&input);
len = GET_32BIT(cp);
if (len < 1 + 2 + 2 || len > 256 * 1024)
- packet_disconnect("Bad packet length %d.", len);
+ packet_disconnect("Bad packet length %u.", len);
padded_len = (len + 8) & ~7;
/* Check if the packet has been entirely received. */
cp = buffer_ptr(&incoming_packet);
packet_length = GET_32BIT(cp);
if (packet_length < 1 + 4 || packet_length > 256 * 1024) {
+#ifdef PACKET_DEBUG
buffer_dump(&incoming_packet);
- packet_disconnect("Bad packet length %d.", packet_length);
+#endif
+ packet_disconnect("Bad packet length %u.", packet_length);
}
- DBG(debug("input: packet len %d", packet_length+4));
+ DBG(debug("input: packet len %u", packet_length+4));
buffer_consume(&input, block_size);
}
/* we have a partial packet of block_size bytes */
* increment sequence number for incoming packet
*/
if (mac && mac->enabled) {
- macbuf = mac_compute(mac, read_seqnr,
+ macbuf = mac_compute(mac, p_read.seqnr,
buffer_ptr(&incoming_packet),
buffer_len(&incoming_packet));
if (memcmp(macbuf, buffer_ptr(&input), mac->mac_len) != 0)
packet_disconnect("Corrupted MAC on input.");
- DBG(debug("MAC #%d ok", read_seqnr));
+ DBG(debug("MAC #%d ok", p_read.seqnr));
buffer_consume(&input, mac->mac_len);
}
if (seqnr_p != NULL)
- *seqnr_p = read_seqnr;
- if (++read_seqnr == 0)
- log("incoming seqnr wraps around");
+ *seqnr_p = p_read.seqnr;
+ if (++p_read.seqnr == 0)
+ logit("incoming seqnr wraps around");
+ if (++p_read.packets == 0)
+ if (!(datafellows & SSH_BUG_NOREKEY))
+ fatal("XXX too many packets with same key");
+ p_read.blocks += (packet_length + 4) / block_size;
/* get padlen */
cp = buffer_ptr(&incoming_packet);
buffer_clear(&incoming_packet);
buffer_append(&incoming_packet, buffer_ptr(&compression_buffer),
buffer_len(&compression_buffer));
- DBG(debug("input: len after de-compress %d", buffer_len(&incoming_packet)));
+ DBG(debug("input: len after de-compress %d",
+ buffer_len(&incoming_packet)));
}
/*
* get packet type, implies consume.
case SSH2_MSG_DISCONNECT:
reason = packet_get_int();
msg = packet_get_string(NULL);
- log("Received disconnect from %s: %u: %.400s",
+ logit("Received disconnect from %s: %u: %.400s",
get_remote_ipaddr(), reason, msg);
xfree(msg);
- fatal_cleanup();
+ cleanup_exit(255);
break;
case SSH2_MSG_UNIMPLEMENTED:
seqnr = packet_get_int();
break;
case SSH_MSG_DISCONNECT:
msg = packet_get_string(NULL);
- log("Received disconnect from %s: %.400s",
+ logit("Received disconnect from %s: %.400s",
get_remote_ipaddr(), msg);
- fatal_cleanup();
+ cleanup_exit(255);
xfree(msg);
break;
default:
packet_get_char(void)
{
char ch;
+
buffer_get(&incoming_packet, &ch, 1);
return (u_char) ch;
}
packet_get_raw(int *length_ptr)
{
int bytes = buffer_len(&incoming_packet);
+
if (length_ptr != NULL)
*length_ptr = bytes;
return buffer_ptr(&incoming_packet);
char buf[1024];
va_list args;
static int disconnecting = 0;
+
if (disconnecting) /* Guard against recursive invocations. */
fatal("packet_disconnect called recursively.");
disconnecting = 1;
vsnprintf(buf, sizeof(buf), fmt, args);
va_end(args);
+ /* Display the error locally */
+ logit("Disconnecting: %.100s", buf);
+
/* Send the disconnect message to the other side, and wait for it to get sent. */
if (compat20) {
packet_start(SSH2_MSG_DISCONNECT);
/* Close the connection. */
packet_close();
-
- /* Display the error locally and exit. */
- log("Disconnecting: %.100s", buf);
- fatal_cleanup();
+ cleanup_exit(255);
}
/* Checks if there is any buffered output, and tries to write some of the output. */
packet_write_poll(void)
{
int len = buffer_len(&output);
+
if (len > 0) {
len = write(connection_out, buffer_ptr(&output), len);
if (len <= 0) {
return buffer_len(&output) < 128 * 1024;
}
+
+static void
+packet_set_tos(int interactive)
+{
+#if defined(IP_TOS) && !defined(IP_TOS_IS_BROKEN)
+ int tos = interactive ? IPTOS_LOWDELAY : IPTOS_THROUGHPUT;
+
+ if (!packet_connection_is_on_socket() ||
+ !packet_connection_is_ipv4())
+ return;
+ if (setsockopt(connection_in, IPPROTO_IP, IP_TOS, &tos,
+ sizeof(tos)) < 0)
+ error("setsockopt IP_TOS %d: %.100s:",
+ tos, strerror(errno));
+#endif
+}
+
/* Informs that the current session is interactive. Sets IP flags for that. */
void
packet_set_interactive(int interactive)
{
static int called = 0;
-#if defined(IP_TOS) && !defined(IP_TOS_IS_BROKEN)
- int lowdelay = IPTOS_LOWDELAY;
- int throughput = IPTOS_THROUGHPUT;
-#endif
if (called)
return;
/* Only set socket options if using a socket. */
if (!packet_connection_is_on_socket())
return;
- /*
- * IPTOS_LOWDELAY and IPTOS_THROUGHPUT are IPv4 only
- */
- if (interactive) {
- /*
- * Set IP options for an interactive connection. Use
- * IPTOS_LOWDELAY and TCP_NODELAY.
- */
-#if defined(IP_TOS) && !defined(IP_TOS_IS_BROKEN)
- if (packet_connection_is_ipv4()) {
- if (setsockopt(connection_in, IPPROTO_IP, IP_TOS,
- &lowdelay, sizeof(lowdelay)) < 0)
- error("setsockopt IPTOS_LOWDELAY: %.100s",
- strerror(errno));
- }
-#endif
+ if (interactive)
set_nodelay(connection_in);
- } else if (packet_connection_is_ipv4()) {
- /*
- * Set IP options for a non-interactive connection. Use
- * IPTOS_THROUGHPUT.
- */
-#if defined(IP_TOS) && !defined(IP_TOS_IS_BROKEN)
- if (setsockopt(connection_in, IPPROTO_IP, IP_TOS, &throughput,
- sizeof(throughput)) < 0)
- error("setsockopt IPTOS_THROUGHPUT: %.100s", strerror(errno));
-#endif
- }
+ packet_set_tos(interactive);
}
/* Returns true if the current connection is interactive. */
return interactive_mode;
}
-int
-packet_set_maxsize(int s)
+u_int
+packet_set_maxsize(u_int s)
{
static int called = 0;
+
if (called) {
- log("packet_set_maxsize: called twice: old %d new %d",
+ logit("packet_set_maxsize: called twice: old %d new %d",
max_packet_size, s);
return -1;
}
if (s < 4 * 1024 || s > 1024 * 1024) {
- log("packet_set_maxsize: bad size %d", s);
+ logit("packet_set_maxsize: bad size %d", s);
return -1;
}
called = 1;
rand >>= 8;
}
}
+
+#define MAX_PACKETS (1<<31)
+int
+packet_need_rekeying(void)
+{
+ if (datafellows & SSH_BUG_NOREKEY)
+ return 0;
+ return
+ (p_send.packets > MAX_PACKETS) ||
+ (p_read.packets > MAX_PACKETS) ||
+ (max_blocks_out && (p_send.blocks > max_blocks_out)) ||
+ (max_blocks_in && (p_read.blocks > max_blocks_in));
+}
+
+void
+packet_set_rekey_limit(u_int32_t bytes)
+{
+ rekey_limit = bytes;
+}
andersk / openssh.git / blobdiff