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SSH compression by linking with zlib.dll if present (compression

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quietly becomes unavailable if zlib.dll not found). Thanks to Joris
van Rantwijk (again).

[originally from svn r511]
This commit is contained in:
Simon Tatham
2000-07-04 09:15:12 +00:00
parent 7a01fd48b6
commit e3e48f45c7
7 changed files with 93 additions and 43 deletions
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103
ssh.c
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@ -15,10 +15,6 @@
#define TRUE 1
#endif
#define logevent(s) { logevent(s); \
if (IS_SCP && (scp_flags & SCP_VERBOSE) != 0) \
fprintf(stderr, "%s\n", s); }
#define SSH_MSG_DISCONNECT 1
#define SSH_SMSG_PUBLIC_KEY 2
#define SSH_CMSG_SESSION_KEY 3
@ -38,11 +34,13 @@
#define SSH_CMSG_EXIT_CONFIRMATION 33
#define SSH_MSG_IGNORE 32
#define SSH_MSG_DEBUG 36
#define SSH_CMSG_REQUEST_COMPRESSION 37
#define SSH_CMSG_AUTH_TIS 39
#define SSH_SMSG_AUTH_TIS_CHALLENGE 40
#define SSH_CMSG_AUTH_TIS_RESPONSE 41
#define SSH_AUTH_TIS 5
#define COMPRESSION_LEVEL 5
#define GET_32BIT(cp) \
(((unsigned long)(unsigned char)(cp)[0] << 24) | \
@ -80,7 +78,7 @@ static SOCKET s = INVALID_SOCKET;
static unsigned char session_key[32];
static struct ssh_cipher *cipher = NULL;
int scp_flags = 0;
static int use_compression = 0;
void (*ssh_get_password)(const char *prompt, char *str, int maxlen) = NULL;
static char *savedhost;
@ -155,6 +153,24 @@ static void ssh_protocol(unsigned char *in, int inlen, int ispkt);
static void ssh_size(void);
static void pktalloc(struct Packet *pkt, long newlen)
{
if (pkt->maxlen < newlen) {
pkt->maxlen = newlen;
#ifdef MSCRYPTOAPI
/* Allocate enough buffer space for extra block
* for MS CryptEncrypt() */
pkt->data = (pkt->data == NULL ? malloc(newlen+8) :
realloc(pkt->data, newlen+8));
#else
pkt->data = (pkt->data == NULL ? malloc(newlen) :
realloc(pkt->data, newlen));
#endif
if (!pkt->data)
fatalbox("Out of memory");
}
}
/*
* Collect incoming data in the incoming packet buffer.
* Decihper and verify the packet when it is completely read.
@ -192,22 +208,9 @@ next_packet:
pad = 8 - (len % 8);
biglen = len + pad;
pktin.length = len - 5;
if (pktin.maxlen < biglen) {
pktin.maxlen = biglen;
#ifdef MSCRYPTOAPI
/* Allocate enough buffer space for extra block
* for MS CryptEncrypt() */
pktin.data = (pktin.data == NULL ? malloc(biglen+8) :
realloc(pktin.data, biglen+8));
#else
pktin.data = (pktin.data == NULL ? malloc(biglen) :
realloc(pktin.data, biglen));
#endif
if (!pktin.data)
fatalbox("Out of memory");
}
if (pktin.maxlen < biglen)
pktalloc(&pktin, biglen);
to_read = biglen;
p = pktin.data;
@ -228,15 +231,23 @@ next_packet:
if (cipher)
cipher->decrypt(pktin.data, biglen);
pktin.type = pktin.data[pad];
pktin.body = pktin.data + pad + 1;
realcrc = crc32(pktin.data, biglen-4);
gotcrc = GET_32BIT(pktin.data+biglen-4);
if (gotcrc != realcrc) {
fatalbox("Incorrect CRC received on packet");
}
if (use_compression) {
ssh_decompress(pktin.data + pad, len - 4, &p, &len);
pktin.length = len - 1;
pktin.type = p[0];
pktin.body = p + 1;
} else {
pktin.length = len - 5;
pktin.type = pktin.data[pad];
pktin.body = pktin.data + pad + 1;
}
if (pktin.type == SSH_SMSG_STDOUT_DATA ||
pktin.type == SSH_SMSG_STDERR_DATA ||
pktin.type == SSH_MSG_DEBUG ||
@ -281,20 +292,8 @@ static void s_wrpkt_start(int type, int len) {
biglen = len + pad;
pktout.length = len-5;
if (pktout.maxlen < biglen) {
pktout.maxlen = biglen;
#ifdef MSCRYPTOAPI
/* Allocate enough buffer space for extra block
* for MS CryptEncrypt() */
pktout.data = (pktout.data == NULL ? malloc(biglen+12) :
realloc(pktout.data, biglen+12));
#else
pktout.data = (pktout.data == NULL ? malloc(biglen+4) :
realloc(pktout.data, biglen+4));
#endif
if (!pktout.data)
fatalbox("Out of memory");
}
if (pktout.maxlen < biglen + 4)
pktalloc(&pktout, biglen + 4);
pktout.type = type;
pktout.body = pktout.data+4+pad+1;
@ -307,8 +306,21 @@ static void s_wrpkt(void) {
len = pktout.length + 5; /* type and CRC */
pad = 8 - (len%8);
biglen = len + pad;
pktout.body[-1] = pktout.type;
if (use_compression) {
unsigned char *p;
unsigned int n;
pktout.body = NULL;
ssh_compress(pktout.data + 4 + pad, pktout.length + 1, &p, &n);
len = n + 4;
pad = 8 - (len%8);
biglen = len + pad;
if (pktout.maxlen < biglen + 4)
pktalloc(&pktout, biglen + 4);
memcpy(pktout.data + 4 + pad, p, n);
}
for (i=0; i<pad; i++)
pktout.data[i+4] = random_byte();
crc = crc32(pktout.data+4, biglen-4);
@ -853,6 +865,21 @@ static int do_ssh_login(unsigned char *in, int inlen, int ispkt)
logevent("Authentication successful");
if (cfg.ssh_compression &&
ssh_compression_init(COMPRESSION_LEVEL)) {
send_packet(SSH_CMSG_REQUEST_COMPRESSION,
PKT_INT, COMPRESSION_LEVEL, PKT_END);
crWaitUntil(ispkt);
if (pktin.type == SSH_SMSG_SUCCESS) {
use_compression = 1;
logevent("Enabled SSH packet compression");
} else if (pktin.type == SSH_SMSG_FAILURE) {
logevent("Server does not support packet compression");
} else {
fatalbox("Strange packet received, type %d", pktin.type);
}
}
crFinish(1);
}