*/
#include "includes.h"
-RCSID("$OpenBSD: packet.c,v 1.87 2002/01/24 21:13:23 stevesk Exp $");
+RCSID("$OpenBSD: packet.c,v 1.100 2002/11/21 22:45:31 markus Exp $");
#include "xmalloc.h"
#include "buffer.h"
#include "log.h"
#include "canohost.h"
#include "misc.h"
+#include "ssh.h"
#ifdef PACKET_DEBUG
#define DBG(x) x
static CipherContext send_context;
/* Buffer for raw input data from the socket. */
-static Buffer input;
+Buffer input;
/* Buffer for raw output data going to the socket. */
-static Buffer output;
+Buffer output;
/* Buffer for the partial outgoing packet being constructed. */
static Buffer outgoing_packet;
/* 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;
+
+/* Session key for protocol v1 */
+static u_char ssh1_key[SSH_SESSION_KEY_LENGTH];
+static u_int ssh1_keylen;
/* roundup current message to extra_pad bytes */
static u_char extra_pad = 0;
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;
connection_out = fd_out;
- cipher_init(&send_context, none, "", 0, NULL, 0);
- cipher_init(&receive_context, none, "", 0, NULL, 0);
+ cipher_init(&send_context, none, "", 0, NULL, 0, CIPHER_ENCRYPT);
+ cipher_init(&receive_context, none, "", 0, NULL, 0, CIPHER_DECRYPT);
newkeys[MODE_IN] = newkeys[MODE_OUT] = NULL;
if (!initialized) {
initialized = 1;
return 1;
}
+/*
+ * Exports an IV from the CipherContext required to export the key
+ * state back from the unprivileged child to the privileged parent
+ * process.
+ */
+
+void
+packet_get_keyiv(int mode, u_char *iv, u_int len)
+{
+ CipherContext *cc;
+
+ if (mode == MODE_OUT)
+ cc = &send_context;
+ else
+ cc = &receive_context;
+
+ cipher_get_keyiv(cc, iv, len);
+}
+
+int
+packet_get_keycontext(int mode, u_char *dat)
+{
+ CipherContext *cc;
+
+ if (mode == MODE_OUT)
+ cc = &send_context;
+ else
+ cc = &receive_context;
+
+ return (cipher_get_keycontext(cc, dat));
+}
+
+void
+packet_set_keycontext(int mode, u_char *dat)
+{
+ CipherContext *cc;
+
+ if (mode == MODE_OUT)
+ cc = &send_context;
+ else
+ cc = &receive_context;
+
+ cipher_set_keycontext(cc, dat);
+}
+
+int
+packet_get_keyiv_len(int mode)
+{
+ CipherContext *cc;
+
+ if (mode == MODE_OUT)
+ cc = &send_context;
+ else
+ cc = &receive_context;
+
+ return (cipher_get_keyiv_len(cc));
+}
+void
+packet_set_iv(int mode, u_char *dat)
+{
+ CipherContext *cc;
+
+ if (mode == MODE_OUT)
+ cc = &send_context;
+ else
+ cc = &receive_context;
+
+ cipher_set_keyiv(cc, dat);
+}
+int
+packet_get_ssh1_cipher()
+{
+ return (cipher_get_number(receive_context.cipher));
+}
+
+
+u_int32_t
+packet_get_seqnr(int mode)
+{
+ return (mode == MODE_IN ? read_seqnr : send_seqnr);
+}
+
+void
+packet_set_seqnr(int mode, u_int32_t seqnr)
+{
+ if (mode == MODE_IN)
+ read_seqnr = seqnr;
+ else if (mode == MODE_OUT)
+ send_seqnr = seqnr;
+ else
+ fatal("packet_set_seqnr: bad mode %d", mode);
+}
+
/* returns 1 if connection is via ipv4 */
int
memset(&to, 0, sizeof(to));
if (getsockname(connection_out, (struct sockaddr *)&to, &tolen) < 0)
return 0;
- if (to.ss_family != AF_INET)
- return 0;
- return 1;
+ if (to.ss_family == AF_INET)
+ return 1;
+#ifdef IPV4_IN_IPV6
+ if (to.ss_family == AF_INET6 &&
+ IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)&to)->sin6_addr))
+ return 1;
+#endif
+ return 0;
}
/* Sets the connection into non-blocking mode. */
buffer_free(&compression_buffer);
buffer_compress_uninit();
}
+ cipher_cleanup(&send_context);
+ cipher_cleanup(&receive_context);
}
/* Sets remote side protocol flags. */
* key is used for both sending and reception. However, both directions are
* encrypted independently of each other.
*/
+
void
packet_set_encryption_key(const u_char *key, u_int keylen,
int number)
{
Cipher *cipher = cipher_by_number(number);
+
if (cipher == NULL)
fatal("packet_set_encryption_key: unknown cipher number %d", number);
if (keylen < 20)
fatal("packet_set_encryption_key: keylen too small: %d", keylen);
- cipher_init(&receive_context, cipher, key, keylen, NULL, 0);
- cipher_init(&send_context, cipher, key, keylen, NULL, 0);
+ if (keylen > SSH_SESSION_KEY_LENGTH)
+ fatal("packet_set_encryption_key: keylen too big: %d", keylen);
+ memcpy(ssh1_key, key, keylen);
+ ssh1_keylen = keylen;
+ cipher_init(&send_context, cipher, key, keylen, NULL, 0, CIPHER_ENCRYPT);
+ cipher_init(&receive_context, cipher, key, keylen, NULL, 0, CIPHER_DECRYPT);
+}
+
+u_int
+packet_get_encryption_key(u_char *key)
+{
+ if (key == NULL)
+ return (ssh1_keylen);
+ memcpy(key, ssh1_key, ssh1_keylen);
+ return (ssh1_keylen);
}
/* Start constructing a packet to send. */
packet_put_char(int value)
{
char ch = value;
+
buffer_append(&outgoing_packet, &ch, 1);
}
void
static void
packet_send1(void)
{
- char buf[8], *cp;
+ u_char buf[8], *cp;
int i, padding, len;
u_int checksum;
u_int32_t rand = 0;
/* Insert padding. Initialized to zero in packet_start1() */
padding = 8 - len % 8;
- if (send_context.cipher->number != SSH_CIPHER_NONE) {
+ if (!send_context.plaintext) {
cp = buffer_ptr(&outgoing_packet);
for (i = 0; i < padding; i++) {
if (i % 4 == 0)
PUT_32BIT(buf, len);
buffer_append(&output, buf, 4);
cp = buffer_append_space(&output, buffer_len(&outgoing_packet));
- cipher_encrypt(&send_context, cp, buffer_ptr(&outgoing_packet),
+ cipher_crypt(&send_context, cp, buffer_ptr(&outgoing_packet),
buffer_len(&outgoing_packet));
#ifdef PACKET_DEBUG
*/
}
-static void
+void
set_newkeys(int mode)
{
Enc *enc;
Mac *mac;
Comp *comp;
CipherContext *cc;
+ int encrypt;
- debug("newkeys: mode %d", mode);
+ debug2("set_newkeys: mode %d", mode);
- cc = (mode == MODE_OUT) ? &send_context : &receive_context;
+ if (mode == MODE_OUT) {
+ cc = &send_context;
+ encrypt = CIPHER_ENCRYPT;
+ } else {
+ cc = &receive_context;
+ encrypt = CIPHER_DECRYPT;
+ }
if (newkeys[mode] != NULL) {
- debug("newkeys: rekeying");
- /* todo: free old keys, reset compression/cipher-ctxt; */
- memset(cc, 0, sizeof(*cc));
+ debug("set_newkeys: rekeying");
+ cipher_cleanup(cc);
enc = &newkeys[mode]->enc;
mac = &newkeys[mode]->mac;
comp = &newkeys[mode]->comp;
if (mac->md != NULL)
mac->enabled = 1;
DBG(debug("cipher_init_context: %d", mode));
- cipher_init(cc, enc->cipher, enc->key, enc->cipher->key_len,
- enc->iv, enc->cipher->block_size);
- memset(enc->iv, 0, enc->cipher->block_size);
- memset(enc->key, 0, enc->cipher->key_len);
+ cipher_init(cc, enc->cipher, enc->key, enc->key_len,
+ enc->iv, enc->block_size, encrypt);
+ /* Deleting the keys does not gain extra security */
+ /* memset(enc->iv, 0, enc->block_size);
+ memset(enc->key, 0, enc->key_len); */
if (comp->type != 0 && comp->enabled == 0) {
packet_init_compression();
if (mode == MODE_OUT)
static void
packet_send2(void)
{
- static u_int32_t seqnr = 0;
- u_char type, *ucp, *macbuf = NULL;
+ u_char type, *cp, *macbuf = NULL;
u_char padlen, pad;
- char *cp;
u_int packet_length = 0;
u_int i, len;
u_int32_t rand = 0;
mac = &newkeys[MODE_OUT]->mac;
comp = &newkeys[MODE_OUT]->comp;
}
- block_size = enc ? enc->cipher->block_size : 8;
+ block_size = enc ? enc->block_size : 8;
- ucp = buffer_ptr(&outgoing_packet);
- type = ucp[5];
+ cp = buffer_ptr(&outgoing_packet);
+ type = cp[5];
#ifdef PACKET_DEBUG
fprintf(stderr, "plain: ");
/* will wrap if extra_pad+padlen > 255 */
extra_pad = roundup(extra_pad, block_size);
pad = extra_pad - ((len + padlen) % extra_pad);
- debug("packet_send2: adding %d (len %d padlen %d extra_pad %d)",
+ debug3("packet_send2: adding %d (len %d padlen %d extra_pad %d)",
pad, len, padlen, extra_pad);
padlen += pad;
extra_pad = 0;
}
cp = buffer_append_space(&outgoing_packet, padlen);
- if (enc && enc->cipher->number != SSH_CIPHER_NONE) {
+ if (enc && !send_context.plaintext) {
/* random padding */
for (i = 0; i < padlen; i++) {
if (i % 4 == 0)
}
/* packet_length includes payload, padding and padding length field */
packet_length = buffer_len(&outgoing_packet) - 4;
- ucp = buffer_ptr(&outgoing_packet);
- PUT_32BIT(ucp, packet_length);
- ucp[4] = padlen;
+ cp = buffer_ptr(&outgoing_packet);
+ PUT_32BIT(cp, packet_length);
+ cp[4] = padlen;
DBG(debug("send: len %d (includes padlen %d)", packet_length+4, padlen));
/* compute MAC over seqnr and packet(length fields, payload, padding) */
if (mac && mac->enabled) {
- macbuf = mac_compute(mac, seqnr,
+ macbuf = mac_compute(mac, send_seqnr,
buffer_ptr(&outgoing_packet),
buffer_len(&outgoing_packet));
- DBG(debug("done calc MAC out #%d", seqnr));
+ DBG(debug("done calc MAC out #%d", send_seqnr));
}
/* encrypt packet and append to output buffer. */
cp = buffer_append_space(&output, buffer_len(&outgoing_packet));
- cipher_encrypt(&send_context, cp, buffer_ptr(&outgoing_packet),
+ cipher_crypt(&send_context, cp, buffer_ptr(&outgoing_packet),
buffer_len(&outgoing_packet));
/* append unencrypted MAC */
if (mac && mac->enabled)
buffer_dump(&output);
#endif
/* increment sequence number for outgoing packets */
- if (++seqnr == 0)
+ if (++send_seqnr == 0)
log("outgoing seqnr wraps around");
buffer_clear(&outgoing_packet);
packet_read_poll1(void)
{
u_int len, padded_len;
- u_char *ucp, type;
- char *cp;
+ u_char *cp, type;
u_int checksum, stored_checksum;
/* Check if input size is less than minimum packet size. */
if (buffer_len(&input) < 4 + 8)
return SSH_MSG_NONE;
/* Get length of incoming packet. */
- ucp = buffer_ptr(&input);
- len = GET_32BIT(ucp);
+ 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. */
* (C)1998 CORE-SDI, Buenos Aires Argentina
* Ariel Futoransky(futo@core-sdi.com)
*/
- if (receive_context.cipher->number != SSH_CIPHER_NONE &&
+ if (!receive_context.plaintext &&
detect_attack(buffer_ptr(&input), padded_len, NULL) == DEATTACK_DETECTED)
packet_disconnect("crc32 compensation attack: network attack detected");
/* Decrypt data to incoming_packet. */
buffer_clear(&incoming_packet);
cp = buffer_append_space(&incoming_packet, padded_len);
- cipher_decrypt(&receive_context, cp, buffer_ptr(&input), padded_len);
+ cipher_crypt(&receive_context, cp, buffer_ptr(&input), padded_len);
buffer_consume(&input, padded_len);
packet_disconnect("packet_read_poll1: len %d != buffer_len %d.",
len, buffer_len(&incoming_packet));
- ucp = (u_char *)buffer_ptr(&incoming_packet) + len - 4;
- stored_checksum = GET_32BIT(ucp);
+ cp = (u_char *)buffer_ptr(&incoming_packet) + len - 4;
+ stored_checksum = GET_32BIT(cp);
if (checksum != stored_checksum)
packet_disconnect("Corrupted check bytes on input.");
buffer_consume_end(&incoming_packet, 4);
static int
packet_read_poll2(u_int32_t *seqnr_p)
{
- static u_int32_t seqnr = 0;
static u_int packet_length = 0;
u_int padlen, need;
- u_char *macbuf, *ucp, type;
- char *cp;
+ u_char *macbuf, *cp, type;
int maclen, block_size;
Enc *enc = NULL;
Mac *mac = NULL;
comp = &newkeys[MODE_IN]->comp;
}
maclen = mac && mac->enabled ? mac->mac_len : 0;
- block_size = enc ? enc->cipher->block_size : 8;
+ block_size = enc ? enc->block_size : 8;
if (packet_length == 0) {
/*
return SSH_MSG_NONE;
buffer_clear(&incoming_packet);
cp = buffer_append_space(&incoming_packet, block_size);
- cipher_decrypt(&receive_context, cp, buffer_ptr(&input),
+ cipher_crypt(&receive_context, cp, buffer_ptr(&input),
block_size);
- ucp = buffer_ptr(&incoming_packet);
- packet_length = GET_32BIT(ucp);
+ cp = buffer_ptr(&incoming_packet);
+ packet_length = GET_32BIT(cp);
if (packet_length < 1 + 4 || packet_length > 256 * 1024) {
buffer_dump(&incoming_packet);
- packet_disconnect("Bad packet length %d.", packet_length);
+ 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 */
buffer_dump(&input);
#endif
cp = buffer_append_space(&incoming_packet, need);
- cipher_decrypt(&receive_context, cp, buffer_ptr(&input), need);
+ cipher_crypt(&receive_context, cp, buffer_ptr(&input), need);
buffer_consume(&input, need);
/*
* compute MAC over seqnr and packet,
* increment sequence number for incoming packet
*/
if (mac && mac->enabled) {
- macbuf = mac_compute(mac, seqnr,
+ macbuf = mac_compute(mac, 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", seqnr));
+ DBG(debug("MAC #%d ok", read_seqnr));
buffer_consume(&input, mac->mac_len);
}
if (seqnr_p != NULL)
- *seqnr_p = seqnr;
- if (++seqnr == 0)
+ *seqnr_p = read_seqnr;
+ if (++read_seqnr == 0)
log("incoming seqnr wraps around");
/* get padlen */
cp = buffer_ptr(&incoming_packet);
- cp += 4;
- padlen = (u_char) *cp;
+ padlen = cp[4];
DBG(debug("input: padlen %d", padlen));
if (padlen < 4)
packet_disconnect("Corrupted padlen %d on input.", padlen);
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.
int
packet_read_poll_seqnr(u_int32_t *seqnr_p)
{
- int reason, seqnr;
+ u_int reason, seqnr;
u_char type;
char *msg;
case SSH2_MSG_DISCONNECT:
reason = packet_get_int();
msg = packet_get_string(NULL);
- log("Received disconnect from %s: %d: %.400s", get_remote_ipaddr(),
- reason, msg);
+ log("Received disconnect from %s: %u: %.400s",
+ get_remote_ipaddr(), reason, msg);
xfree(msg);
fatal_cleanup();
break;
case SSH2_MSG_UNIMPLEMENTED:
seqnr = packet_get_int();
- debug("Received SSH2_MSG_UNIMPLEMENTED for %d", seqnr);
+ debug("Received SSH2_MSG_UNIMPLEMENTED for %u",
+ seqnr);
break;
default:
return type;
break;
case SSH_MSG_DISCONNECT:
msg = packet_get_string(NULL);
- log("Received disconnect from %s: %.400s", get_remote_ipaddr(),
- msg);
+ log("Received disconnect from %s: %.400s",
+ get_remote_ipaddr(), msg);
fatal_cleanup();
xfree(msg);
break;
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 */
+ log("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();
}
packet_write_poll(void)
{
int len = buffer_len(&output);
+
if (len > 0) {
len = write(connection_out, buffer_ptr(&output), len);
if (len <= 0) {
#if defined(IP_TOS) && !defined(IP_TOS_IS_BROKEN)
if (packet_connection_is_ipv4()) {
if (setsockopt(connection_in, IPPROTO_IP, IP_TOS,
- (void *) &lowdelay, sizeof(lowdelay)) < 0)
+ &lowdelay, sizeof(lowdelay)) < 0)
error("setsockopt IPTOS_LOWDELAY: %.100s",
strerror(errno));
}
* IPTOS_THROUGHPUT.
*/
#if defined(IP_TOS) && !defined(IP_TOS_IS_BROKEN)
- if (setsockopt(connection_in, IPPROTO_IP, IP_TOS, (void *) &throughput,
+ if (setsockopt(connection_in, IPPROTO_IP, IP_TOS, &throughput,
sizeof(throughput)) < 0)
error("setsockopt IPTOS_THROUGHPUT: %.100s", strerror(errno));
#endif
packet_set_maxsize(int s)
{
static int called = 0;
+
if (called) {
log("packet_set_maxsize: called twice: old %d new %d",
max_packet_size, s);
andersk / openssh.git / blobdiff