[u/mdw/putty] / ssh.c

#include <stdio.h>
#include <stdlib.h>
#include <winsock.h>

#include "putty.h"

#ifndef FALSE
#define FALSE 0
#endif
#ifndef TRUE
#define TRUE 1
#endif

#include "ssh.h"

#define SSH_MSG_DISCONNECT 1
#define SSH_SMSG_PUBLIC_KEY 2
#define SSH_CMSG_SESSION_KEY 3
#define SSH_CMSG_USER 4
#define SSH_CMSG_AUTH_PASSWORD 9
#define SSH_CMSG_REQUEST_PTY 10
#define SSH_CMSG_EXEC_SHELL 12
#define SSH_CMSG_STDIN_DATA 16
#define SSH_SMSG_STDOUT_DATA 17
#define SSH_SMSG_STDERR_DATA 18
#define SSH_SMSG_SUCCESS 14
#define SSH_SMSG_FAILURE 15
#define SSH_SMSG_EXITSTATUS 20
#define SSH_MSG_IGNORE 32
#define SSH_CMSG_EXIT_CONFIRMATION 33
#define SSH_MSG_DEBUG 36

/* Coroutine mechanics for the sillier bits of the code */
#define crBegin1	static int crLine = 0;
#define crBegin2	switch(crLine) { case 0:;
#define crBegin		crBegin1; crBegin2;
#define crFinish(z)	} crLine = 0; return (z)
#define crFinishV	} crLine = 0; return
#define crReturn(z)	\
	do {\
	    crLine=__LINE__; return (z); case __LINE__:;\
	} while (0)
#define crReturnV	\
	do {\
	    crLine=__LINE__; return; case __LINE__:;\
	} while (0)
#define crStop(z)	do{ crLine = 0; return (z); }while(0)
#define crStopV		do{ crLine = 0; return; }while(0)

#ifndef FALSE
#define FALSE 0
#endif
#ifndef TRUE
#define TRUE 1
#endif

static SOCKET s = INVALID_SOCKET;

static unsigned char session_key[32];
static struct ssh_cipher *cipher = NULL;

static char *savedhost;

static enum {
    SSH_STATE_BEFORE_SIZE,
    SSH_STATE_INTERMED,
    SSH_STATE_SESSION,
    SSH_STATE_CLOSED
} ssh_state = SSH_STATE_BEFORE_SIZE;

static int size_needed = FALSE;

static void s_write (char *buf, int len) {
    while (len > 0) {
	int i = send (s, buf, len, 0);
	if (i > 0)
	    len -= i, buf += i;
    }
}

static int s_read (char *buf, int len) {
    int ret = 0;
    while (len > 0) {
	int i = recv (s, buf, len, 0);
	if (i > 0)
	    len -= i, buf += i, ret += i;
	else
	    return i;
    }
    return ret;
}

static void c_write (char *buf, int len) {
    while (len--) {
	int new_head = (inbuf_head + 1) & INBUF_MASK;
	if (new_head != inbuf_reap) {
	    inbuf[inbuf_head] = *buf++;
	    inbuf_head = new_head;
	}
    }
}

struct Packet {
    long length;
    int type;
    unsigned long crc;
    unsigned char *data;
    unsigned char *body;
    long maxlen;
};

static struct Packet pktin = { 0, 0, 0, NULL, 0 };
static struct Packet pktout = { 0, 0, 0, NULL, 0 };

static void ssh_protocol(unsigned char *in, int inlen, int ispkt);
static void ssh_size(void);

static void ssh_gotdata(unsigned char *data, int datalen) {
    static long len, biglen, to_read;
    static unsigned char *p;
    static int i, pad;

    crBegin;
    while (1) {
	for (i = len = 0; i < 4; i++) {
	    while (datalen == 0)
		crReturnV;
	    len = (len << 8) + *data;
	    data++, datalen--;
	}

#ifdef FWHACK
        if (len == 0x52656d6f) {       /* "Remo"te server has closed ... */
            len = 0x300;               /* big enough to carry to end */
        }
#endif

	pad = 8 - (len%8);

	biglen = len + pad;

	len -= 5;		       /* type and CRC */

	pktin.length = len;
	if (pktin.maxlen < biglen) {
	    pktin.maxlen = biglen;
	    pktin.data = (pktin.data == NULL ? malloc(biglen) :
			realloc(pktin.data, biglen));
	    if (!pktin.data)
		fatalbox("Out of memory");
	}

	p = pktin.data, to_read = biglen;
	while (to_read > 0) {
	    static int chunk;
	    chunk = to_read;
	    while (datalen == 0)
		crReturnV;
	    if (chunk > datalen)
		chunk = datalen;
	    memcpy(p, data, chunk);
	    data += chunk;
	    datalen -= chunk;
	    p += chunk;
	    to_read -= chunk;
	}

	if (cipher)
	    cipher->decrypt(pktin.data, biglen);

	pktin.type = pktin.data[pad];
	pktin.body = pktin.data+pad+1;

	if (pktin.type == SSH_MSG_DEBUG) {
	    /* FIXME: log it */
	} else if (pktin.type == SSH_MSG_IGNORE) {
	    /* do nothing */;
	} else
	    ssh_protocol(NULL, 0, 1);
    }
    crFinishV;
}

static void s_wrpkt_start(int type, int len) {
    int pad, biglen;

    len += 5;			       /* type and CRC */
    pad = 8 - (len%8);
    biglen = len + pad;

    pktout.length = len-5;
    if (pktout.maxlen < biglen) {
	pktout.maxlen = biglen;
	pktout.data = (pktout.data == NULL ? malloc(biglen+4) :
		       realloc(pktout.data, biglen+4));
	if (!pktout.data)
	    fatalbox("Out of memory");
    }

    pktout.type = type;
    pktout.body = pktout.data+4+pad+1;
}

static void s_wrpkt(void) {
    int pad, len, biglen, i;
    unsigned long crc;

    len = pktout.length + 5;	       /* type and CRC */
    pad = 8 - (len%8);
    biglen = len + pad;

    pktout.body[-1] = pktout.type;
    for (i=0; i<pad; i++)
	pktout.data[i+4] = random_byte();
    crc = crc32(pktout.data+4, biglen-4);

    pktout.data[biglen+0] = (unsigned char) ((crc >> 24) & 0xFF);
    pktout.data[biglen+1] = (unsigned char) ((crc >> 16) & 0xFF);
    pktout.data[biglen+2] = (unsigned char) ((crc >> 8) & 0xFF);
    pktout.data[biglen+3] = (unsigned char) (crc & 0xFF);

    pktout.data[0] = (len >> 24) & 0xFF;
    pktout.data[1] = (len >> 16) & 0xFF;
    pktout.data[2] = (len >> 8) & 0xFF;
    pktout.data[3] = len & 0xFF;

    if (cipher)
	cipher->encrypt(pktout.data+4, biglen);

    s_write(pktout.data, biglen+4);
}

static int ssh_versioncmp(char *a, char *b) {
    char *ae, *be;
    unsigned long av, bv;

    av = strtoul(a, &ae, 10);
    bv = strtoul(b, &be, 10);
    if (av != bv) return (av < bv ? -1 : +1);
    if (*ae == '.') ae++;
    if (*be == '.') be++;
    av = strtoul(ae, &ae, 10);
    bv = strtoul(be, &be, 10);
    if (av != bv) return (av < bv ? -1 : +1);
    return 0;
}

static int do_ssh_init(void) {
    char c;
    char version[10];
    char vstring[40];
    int i;

#ifdef FWHACK
    i = 0;
    while (s_read(&c, 1) == 1) {
	if (c == 'S' && i < 2) i++;
	else if (c == 'S' && i == 2) i = 2;
	else if (c == 'H' && i == 2) break;
	else i = 0;
    }
#else
    if (s_read(&c,1) != 1 || c != 'S') return 0;
    if (s_read(&c,1) != 1 || c != 'S') return 0;
    if (s_read(&c,1) != 1 || c != 'H') return 0;
#endif
    if (s_read(&c,1) != 1 || c != '-') return 0;
    i = 0;
    while (1) {
	if (s_read(&c,1) != 1)
	    return 0;
	if (i >= 0) {
	    if (c == '-') {
		version[i] = '\0';
		i = -1;
	    } else if (i < sizeof(version)-1)
		version[i++] = c;
	}
	else if (c == '\n')
	    break;
    }

    sprintf(vstring, "SSH-%s-PuTTY\n",
	    (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"));
    s_write(vstring, strlen(vstring));
    return 1;
}

static void ssh_protocol(unsigned char *in, int inlen, int ispkt) {
    int i, j, len;
    unsigned char session_id[16];
    unsigned char *rsabuf, *keystr1, *keystr2;
    unsigned char cookie[8];
    struct RSAKey servkey, hostkey;
    struct MD5Context md5c;
    unsigned long supported_ciphers_mask;
    int cipher_type;

    extern struct ssh_cipher ssh_3des;
    extern struct ssh_cipher ssh_des;
    extern struct ssh_cipher ssh_blowfish;

    crBegin;

    random_init();

    while (!ispkt)
	crReturnV;

    if (pktin.type != SSH_SMSG_PUBLIC_KEY)
	fatalbox("Public key packet not received");

    memcpy(cookie, pktin.body, 8);

    MD5Init(&md5c);

    i = makekey(pktin.body+8, &servkey, &keystr1);

    j = makekey(pktin.body+8+i, &hostkey, &keystr2);

    supported_ciphers_mask = (pktin.body[12+i+j] << 24) |
                             (pktin.body[13+i+j] << 16) |
                             (pktin.body[14+i+j] << 8) |
                             (pktin.body[15+i+j]);

    MD5Update(&md5c, keystr2, hostkey.bytes);
    MD5Update(&md5c, keystr1, servkey.bytes);
    MD5Update(&md5c, pktin.body, 8);

    MD5Final(session_id, &md5c);

    for (i=0; i<32; i++)
	session_key[i] = random_byte();

    len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);

    rsabuf = malloc(len);
    if (!rsabuf)
	fatalbox("Out of memory");

    verify_ssh_host_key(savedhost, &hostkey);

    for (i=0; i<32; i++) {
	rsabuf[i] = session_key[i];
	if (i < 16)
	    rsabuf[i] ^= session_id[i];
    }

    if (hostkey.bytes > servkey.bytes) {
	rsaencrypt(rsabuf, 32, &servkey);
	rsaencrypt(rsabuf, servkey.bytes, &hostkey);
    } else {
	rsaencrypt(rsabuf, 32, &hostkey);
	rsaencrypt(rsabuf, hostkey.bytes, &servkey);
    }

    cipher_type = cfg.cipher == CIPHER_BLOWFISH ? SSH_CIPHER_BLOWFISH :
                  cfg.cipher == CIPHER_DES ? SSH_CIPHER_DES : 
                  SSH_CIPHER_3DES;
    if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
	c_write("Selected cipher not supported, falling back to 3DES\r\n", 53);
	cipher_type = SSH_CIPHER_3DES;
    }

    s_wrpkt_start(SSH_CMSG_SESSION_KEY, len+15);
    pktout.body[0] = cipher_type;
    memcpy(pktout.body+1, cookie, 8);
    pktout.body[9] = (len*8) >> 8;
    pktout.body[10] = (len*8) & 0xFF;
    memcpy(pktout.body+11, rsabuf, len);
    pktout.body[len+11] = pktout.body[len+12] = 0;   /* protocol flags */
    pktout.body[len+13] = pktout.body[len+14] = 0;
    s_wrpkt();

    free(rsabuf);

    cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish :
             cipher_type == SSH_CIPHER_DES ? &ssh_des :
             &ssh_3des;
    cipher->sesskey(session_key);

    do { crReturnV; } while (!ispkt);

    if (pktin.type != SSH_SMSG_SUCCESS)
	fatalbox("Encryption not successfully enabled");

    fflush(stdout);
    {
	static char username[100];
	static int pos = 0;
	static char c;
	if (!*cfg.username) {
	    c_write("login as: ", 10);
	    while (pos >= 0) {
		do { crReturnV; } while (ispkt);
		while (inlen--) switch (c = *in++) {
		  case 10: case 13:
		    username[pos] = 0;
		    pos = -1;
		    break;
		  case 8: case 127:
		    if (pos > 0) {
			c_write("\b \b", 3);
			pos--;
		    }
		    break;
		  case 21: case 27:
		    while (pos > 0) {
			c_write("\b \b", 3);
			pos--;
		    }
		    break;
		  case 3: case 4:
		    random_save_seed();
		    exit(0);
		    break;
		  default:
		    if (c >= ' ' && c <= '~' && pos < 40) {
			username[pos++] = c;
			c_write(&c, 1);
		    }
		    break;
		}
	    }
	    c_write("\r\n", 2);
	    username[strcspn(username, "\n\r")] = '\0';
	} else {
	    char stuff[200];
	    strncpy(username, cfg.username, 99);
	    username[99] = '\0';
	    sprintf(stuff, "Sent username \"%s\".\r\n", username);
	    c_write(stuff, strlen(stuff));
	}
	s_wrpkt_start(SSH_CMSG_USER, 4+strlen(username));
	pktout.body[0] = pktout.body[1] = pktout.body[2] = 0;
	pktout.body[3] = strlen(username);
	memcpy(pktout.body+4, username, strlen(username));
	s_wrpkt();
    }

    do { crReturnV; } while (!ispkt);

    while (pktin.type == SSH_SMSG_FAILURE) {
	static char password[100];
	static int pos;
	static char c;
	c_write("password: ", 10);
	pos = 0;
	while (pos >= 0) {
	    do { crReturnV; } while (ispkt);
	    while (inlen--) switch (c = *in++) {
	      case 10: case 13:
		password[pos] = 0;
		pos = -1;
		break;
	      case 8: case 127:
		if (pos > 0)
		    pos--;
		break;
	      case 21: case 27:
		pos = 0;
		break;
	      case 3: case 4:
		random_save_seed();
		exit(0);
		break;
	      default:
		if (c >= ' ' && c <= '~' && pos < 40)
		    password[pos++] = c;
		break;
	    }
	}
	c_write("\r\n", 2);
	s_wrpkt_start(SSH_CMSG_AUTH_PASSWORD, 4+strlen(password));
	pktout.body[0] = pktout.body[1] = pktout.body[2] = 0;
	pktout.body[3] = strlen(password);
	memcpy(pktout.body+4, password, strlen(password));
	s_wrpkt();
	memset(password, 0, strlen(password));
	do { crReturnV; } while (!ispkt);
	if (pktin.type == 15) {
	    c_write("Access denied\r\n", 15);
	} else if (pktin.type != 14) {
	    fatalbox("Strange packet received, type %d", pktin.type);
	}
    }

    if (!cfg.nopty) {
        i = strlen(cfg.termtype);
        s_wrpkt_start(SSH_CMSG_REQUEST_PTY, i+5*4+1);
        pktout.body[0] = (i >> 24) & 0xFF;
        pktout.body[1] = (i >> 16) & 0xFF;
        pktout.body[2] = (i >> 8) & 0xFF;
        pktout.body[3] = i & 0xFF;
        memcpy(pktout.body+4, cfg.termtype, i);
        i += 4;
        pktout.body[i++] = (rows >> 24) & 0xFF;
        pktout.body[i++] = (rows >> 16) & 0xFF;
        pktout.body[i++] = (rows >> 8) & 0xFF;
        pktout.body[i++] = rows & 0xFF;
        pktout.body[i++] = (cols >> 24) & 0xFF;
        pktout.body[i++] = (cols >> 16) & 0xFF;
        pktout.body[i++] = (cols >> 8) & 0xFF;
        pktout.body[i++] = cols & 0xFF;
        memset(pktout.body+i, 0, 9);       /* 0 pixwidth, 0 pixheight, 0.b endofopt */
        s_wrpkt();
        ssh_state = SSH_STATE_INTERMED;
        do { crReturnV; } while (!ispkt);
        if (pktin.type != SSH_MSG_SUCCESS && pktin.type != SSH_MSG_FAILURE) {
            fatalbox("Protocol confusion");
        } else if (pktin.type == SSH_MSG_FAILURE) {
            c_write("Server refused to allocate pty\r\n", 32);
        }
    }

    s_wrpkt_start(SSH_CMSG_EXEC_SHELL, 0);
    s_wrpkt();

    ssh_state = SSH_STATE_SESSION;
    if (size_needed)
	ssh_size();

    while (1) {
	crReturnV;
	if (ispkt) {
	    if (pktin.type == SSH_SMSG_STDOUT_DATA ||
                pktin.type == SSH_SMSG_STDERR_DATA) {
		long len = 0;
		for (i = 0; i < 4; i++)
		    len = (len << 8) + pktin.body[i];
		c_write(pktin.body+4, len);
	    } else if (pktin.type == SSH_MSG_DISCONNECT) {
                ssh_state = SSH_STATE_CLOSED;
	    } else if (pktin.type == SSH_MSG_SUCCESS) {
		/* may be from EXEC_SHELL on some servers */
	    } else if (pktin.type == SSH_MSG_FAILURE) {
		/* may be from EXEC_SHELL on some servers
		 * if no pty is available or in other odd cases. Ignore */
	    } else if (pktin.type == SSH_SMSG_EXITSTATUS) {
		s_wrpkt_start(SSH_CMSG_EXIT_CONFIRMATION, 0);
		s_wrpkt();
	    } else {
		fatalbox("Strange packet received: type %d", pktin.type);
	    }
	} else {
	    s_wrpkt_start(SSH_CMSG_STDIN_DATA, 4+inlen);
	    pktout.body[0] = (inlen >> 24) & 0xFF;
	    pktout.body[1] = (inlen >> 16) & 0xFF;
	    pktout.body[2] = (inlen >> 8) & 0xFF;
	    pktout.body[3] = inlen & 0xFF;
	    memcpy(pktout.body+4, in, inlen);
	    s_wrpkt();
	}
    }

    crFinishV;
}

/*
 * Called to set up the connection. Will arrange for WM_NETEVENT
 * messages to be passed to the specified window, whose window
 * procedure should then call telnet_msg().
 *
 * Returns an error message, or NULL on success.
 *
 * Also places the canonical host name into `realhost'.
 */
static char *ssh_init (HWND hwnd, char *host, int port, char **realhost) {
    SOCKADDR_IN addr;
    struct hostent *h;
    unsigned long a;
#ifdef FWHACK
    char *FWhost;
    int FWport;
#endif

    savedhost = malloc(1+strlen(host));
    if (!savedhost)
	fatalbox("Out of memory");
    strcpy(savedhost, host);

#ifdef FWHACK
    FWhost = host;
    FWport = port;
    host = FWSTR;
    port = 23;
#endif

    /*
     * Try to find host.
     */
    if ( (a = inet_addr(host)) == (unsigned long) INADDR_NONE) {
	if ( (h = gethostbyname(host)) == NULL)
	    switch (WSAGetLastError()) {
	      case WSAENETDOWN: return "Network is down";
	      case WSAHOST_NOT_FOUND: case WSANO_DATA:
		return "Host does not exist";
	      case WSATRY_AGAIN: return "Host not found";
	      default: return "gethostbyname: unknown error";
	    }
	memcpy (&a, h->h_addr, sizeof(a));
	*realhost = h->h_name;
    } else
	*realhost = host;
#ifdef FWHACK
    *realhost = FWhost;
#endif
    a = ntohl(a);

    if (port < 0)
	port = 22;		       /* default ssh port */

    /*
     * Open socket.
     */
    s = socket(AF_INET, SOCK_STREAM, 0);
    if (s == INVALID_SOCKET)
	switch (WSAGetLastError()) {
	  case WSAENETDOWN: return "Network is down";
	  case WSAEAFNOSUPPORT: return "TCP/IP support not present";
	  default: return "socket(): unknown error";
	}

    /*
     * Bind to local address.
     */
    addr.sin_family = AF_INET;
    addr.sin_addr.s_addr = htonl(INADDR_ANY);
    addr.sin_port = htons(0);
    if (bind (s, (struct sockaddr *)&addr, sizeof(addr)) == SOCKET_ERROR)
	switch (WSAGetLastError()) {
	  case WSAENETDOWN: return "Network is down";
	  default: return "bind(): unknown error";
	}

    /*
     * Connect to remote address.
     */
    addr.sin_addr.s_addr = htonl(a);
    addr.sin_port = htons((short)port);
    if (connect (s, (struct sockaddr *)&addr, sizeof(addr)) == SOCKET_ERROR)
	switch (WSAGetLastError()) {
	  case WSAENETDOWN: return "Network is down";
	  case WSAECONNREFUSED: return "Connection refused";
	  case WSAENETUNREACH: return "Network is unreachable";
	  case WSAEHOSTUNREACH: return "No route to host";
	  default: return "connect(): unknown error";
	}

#ifdef FWHACK
    send(s, "connect ", 8, 0);
    send(s, FWhost, strlen(FWhost), 0);
    {
	char buf[20];
	sprintf(buf, " %d\n", FWport);
	send (s, buf, strlen(buf), 0);
    }
#endif

    if (!do_ssh_init())
	return "Protocol initialisation error";

    if (WSAAsyncSelect (s, hwnd, WM_NETEVENT, FD_READ | FD_CLOSE) == SOCKET_ERROR)
	switch (WSAGetLastError()) {
	  case WSAENETDOWN: return "Network is down";
	  default: return "WSAAsyncSelect(): unknown error";
	}

    return NULL;
}

/*
 * Process a WM_NETEVENT message. Will return 0 if the connection
 * has closed, or <0 for a socket error.
 */
static int ssh_msg (WPARAM wParam, LPARAM lParam) {
    int ret;
    char buf[256];

    if (s == INVALID_SOCKET)	       /* how the hell did we get here?! */
	return -5000;

    if (WSAGETSELECTERROR(lParam) != 0)
	return -WSAGETSELECTERROR(lParam);

    switch (WSAGETSELECTEVENT(lParam)) {
      case FD_READ:
	ret = recv(s, buf, sizeof(buf), 0);
	if (ret < 0 && WSAGetLastError() == WSAEWOULDBLOCK)
	    return 1;
	if (ret < 0)		       /* any _other_ error */
	    return -10000-WSAGetLastError();
	if (ret == 0) {
	    s = INVALID_SOCKET;
	    return 0;		       /* can't happen, in theory */
	}
	ssh_gotdata (buf, ret);
	return 1;
      case FD_CLOSE:
	s = INVALID_SOCKET;
        ssh_state = SSH_STATE_CLOSED;
	return 0;
    }
    return 1;			       /* shouldn't happen, but WTF */
}

/*
 * Called to send data down the Telnet connection.
 */
static void ssh_send (char *buf, int len) {
    if (s == INVALID_SOCKET)
	return;

    ssh_protocol(buf, len, 0);
}

/*
 * Called to set the size of the window from Telnet's POV.
 */
static void ssh_size(void) {
    switch (ssh_state) {
      case SSH_STATE_BEFORE_SIZE:
      case SSH_STATE_CLOSED:
	break;			       /* do nothing */
      case SSH_STATE_INTERMED:
	size_needed = TRUE;	       /* buffer for later */
	break;
      case SSH_STATE_SESSION:
        if (!cfg.nopty) {
            s_wrpkt_start(11, 16);
            pktout.body[0] = (rows >> 24) & 0xFF;
            pktout.body[1] = (rows >> 16) & 0xFF;
            pktout.body[2] = (rows >> 8) & 0xFF;
            pktout.body[3] = rows & 0xFF;
            pktout.body[4] = (cols >> 24) & 0xFF;
            pktout.body[5] = (cols >> 16) & 0xFF;
            pktout.body[6] = (cols >> 8) & 0xFF;
            pktout.body[7] = cols & 0xFF;
            memset(pktout.body+8, 0, 8);
            s_wrpkt();
        }
    }
}

/*
 * (Send Telnet special codes)
 */
static void ssh_special (Telnet_Special code) {
    /* do nothing */
}

Backend ssh_backend = {
    ssh_init,
    ssh_msg,
    ssh_send,
    ssh_size,
    ssh_special
};
Commit	Line	Data
374330e2	1	#include <stdio.h>
	2	#include <stdlib.h>
	3	#include <winsock.h>
	4
	5	#include "putty.h"
	6
	7	#ifndef FALSE
	8	#define FALSE 0
	9	#endif
	10	#ifndef TRUE
	11	#define TRUE 1
	12	#endif
	13
	14	#include "ssh.h"
	15
972a41c8	16	#define SSH_MSG_DISCONNECT 1
	17	#define SSH_SMSG_PUBLIC_KEY 2
	18	#define SSH_CMSG_SESSION_KEY 3
	19	#define SSH_CMSG_USER 4
	20	#define SSH_CMSG_AUTH_PASSWORD 9
	21	#define SSH_CMSG_REQUEST_PTY 10
	22	#define SSH_CMSG_EXEC_SHELL 12
	23	#define SSH_CMSG_STDIN_DATA 16
	24	#define SSH_SMSG_STDOUT_DATA 17
	25	#define SSH_SMSG_STDERR_DATA 18
	26	#define SSH_SMSG_SUCCESS 14
	27	#define SSH_SMSG_FAILURE 15
	28	#define SSH_SMSG_EXITSTATUS 20
	29	#define SSH_MSG_IGNORE 32
	30	#define SSH_CMSG_EXIT_CONFIRMATION 33
	31	#define SSH_MSG_DEBUG 36
	32
374330e2	33	/* Coroutine mechanics for the sillier bits of the code */
	34	#define crBegin1 static int crLine = 0;
	35	#define crBegin2 switch(crLine) { case 0:;
	36	#define crBegin crBegin1; crBegin2;
	37	#define crFinish(z) } crLine = 0; return (z)
	38	#define crFinishV } crLine = 0; return
	39	#define crReturn(z) \
	40	do {\
	41	crLine=__LINE__; return (z); case __LINE__:;\
	42	} while (0)
	43	#define crReturnV \
	44	do {\
	45	crLine=__LINE__; return; case __LINE__:;\
	46	} while (0)
	47	#define crStop(z) do{ crLine = 0; return (z); }while(0)
	48	#define crStopV do{ crLine = 0; return; }while(0)
	49
	50	#ifndef FALSE
	51	#define FALSE 0
	52	#endif
	53	#ifndef TRUE
	54	#define TRUE 1
	55	#endif
	56
	57	static SOCKET s = INVALID_SOCKET;
	58
	59	static unsigned char session_key[32];
	60	static struct ssh_cipher *cipher = NULL;
	61
	62	static char *savedhost;
	63
	64	static enum {
	65	SSH_STATE_BEFORE_SIZE,
	66	SSH_STATE_INTERMED,
21248260	67	SSH_STATE_SESSION,
21248260	68	SSH_STATE_CLOSED
374330e2	69	} ssh_state = SSH_STATE_BEFORE_SIZE;
	70
	71	static int size_needed = FALSE;
	72
	73	static void s_write (char *buf, int len) {
	74	while (len > 0) {
	75	int i = send (s, buf, len, 0);
	76	if (i > 0)
	77	len -= i, buf += i;
	78	}
	79	}
	80
	81	static int s_read (char *buf, int len) {
	82	int ret = 0;
	83	while (len > 0) {
	84	int i = recv (s, buf, len, 0);
	85	if (i > 0)
	86	len -= i, buf += i, ret += i;
	87	else
	88	return i;
	89	}
	90	return ret;
	91	}
	92
	93	static void c_write (char *buf, int len) {
	94	while (len--) {
	95	int new_head = (inbuf_head + 1) & INBUF_MASK;
374330e2	96	if (new_head != inbuf_reap) {
	97	inbuf[inbuf_head] = *buf++;
	98	inbuf_head = new_head;
	99	}
	100	}
	101	}
	102
	103	struct Packet {
	104	long length;
	105	int type;
	106	unsigned long crc;
	107	unsigned char *data;
	108	unsigned char *body;
	109	long maxlen;
	110	};
	111
	112	static struct Packet pktin = { 0, 0, 0, NULL, 0 };
	113	static struct Packet pktout = { 0, 0, 0, NULL, 0 };
	114
	115	static void ssh_protocol(unsigned char *in, int inlen, int ispkt);
	116	static void ssh_size(void);
	117
	118	static void ssh_gotdata(unsigned char *data, int datalen) {
	119	static long len, biglen, to_read;
f67b4e85	120	static unsigned char *p;
374330e2	121	static int i, pad;
374330e2	122
	123	crBegin;
	124	while (1) {
	125	for (i = len = 0; i < 4; i++) {
	126	while (datalen == 0)
	127	crReturnV;
	128	len = (len << 8) + *data;
	129	data++, datalen--;
	130	}
	131
37508af4	132	#ifdef FWHACK
	133	if (len == 0x52656d6f) { /* "Remo"te server has closed ... */
	134	len = 0x300; /* big enough to carry to end */
	135	}
	136	#endif
	137
374330e2	138	pad = 8 - (len%8);
	139
	140	biglen = len + pad;
	141
	142	len -= 5; /* type and CRC */
	143
	144	pktin.length = len;
	145	if (pktin.maxlen < biglen) {
	146	pktin.maxlen = biglen;
	147	pktin.data = (pktin.data == NULL ? malloc(biglen) :
	148	realloc(pktin.data, biglen));
	149	if (!pktin.data)
	150	fatalbox("Out of memory");
	151	}
	152
	153	p = pktin.data, to_read = biglen;
	154	while (to_read > 0) {
	155	static int chunk;
	156	chunk = to_read;
	157	while (datalen == 0)
	158	crReturnV;
	159	if (chunk > datalen)
	160	chunk = datalen;
	161	memcpy(p, data, chunk);
	162	data += chunk;
	163	datalen -= chunk;
	164	p += chunk;
	165	to_read -= chunk;
	166	}
	167
	168	if (cipher)
	169	cipher->decrypt(pktin.data, biglen);
	170
	171	pktin.type = pktin.data[pad];
	172	pktin.body = pktin.data+pad+1;
	173
972a41c8	174	if (pktin.type == SSH_MSG_DEBUG) {
374330e2	175	/* FIXME: log it */
972a41c8	176	} else if (pktin.type == SSH_MSG_IGNORE) {
96b9dc0a	177	/* do nothing */;
374330e2	178	} else
	179	ssh_protocol(NULL, 0, 1);
	180	}
	181	crFinishV;
	182	}
	183
	184	static void s_wrpkt_start(int type, int len) {
	185	int pad, biglen;
	186
	187	len += 5; /* type and CRC */
	188	pad = 8 - (len%8);
	189	biglen = len + pad;
	190
	191	pktout.length = len-5;
	192	if (pktout.maxlen < biglen) {
	193	pktout.maxlen = biglen;
c1f5f956	194	pktout.data = (pktout.data == NULL ? malloc(biglen+4) :
c1f5f956	195	realloc(pktout.data, biglen+4));
374330e2	196	if (!pktout.data)
	197	fatalbox("Out of memory");
	198	}
	199
	200	pktout.type = type;
	201	pktout.body = pktout.data+4+pad+1;
	202	}
	203
	204	static void s_wrpkt(void) {
	205	int pad, len, biglen, i;
	206	unsigned long crc;
	207
	208	len = pktout.length + 5; /* type and CRC */
	209	pad = 8 - (len%8);
	210	biglen = len + pad;
	211
	212	pktout.body[-1] = pktout.type;
	213	for (i=0; i<pad; i++)
	214	pktout.data[i+4] = random_byte();
	215	crc = crc32(pktout.data+4, biglen-4);
	216
	217	pktout.data[biglen+0] = (unsigned char) ((crc >> 24) & 0xFF);
	218	pktout.data[biglen+1] = (unsigned char) ((crc >> 16) & 0xFF);
	219	pktout.data[biglen+2] = (unsigned char) ((crc >> 8) & 0xFF);
	220	pktout.data[biglen+3] = (unsigned char) (crc & 0xFF);
	221
	222	pktout.data[0] = (len >> 24) & 0xFF;
	223	pktout.data[1] = (len >> 16) & 0xFF;
	224	pktout.data[2] = (len >> 8) & 0xFF;
	225	pktout.data[3] = len & 0xFF;
	226
	227	if (cipher)
	228	cipher->encrypt(pktout.data+4, biglen);
	229
	230	s_write(pktout.data, biglen+4);
	231	}
	232
9697bfd2	233	static int ssh_versioncmp(char a, char b) {
	234	char ae, be;
	235	unsigned long av, bv;
	236
43aa02a7	237	av = strtoul(a, &ae, 10);
43aa02a7	238	bv = strtoul(b, &be, 10);
9697bfd2	239	if (av != bv) return (av < bv ? -1 : +1);
	240	if (*ae == '.') ae++;
	241	if (*be == '.') be++;
43aa02a7	242	av = strtoul(ae, &ae, 10);
43aa02a7	243	bv = strtoul(be, &be, 10);
9697bfd2	244	if (av != bv) return (av < bv ? -1 : +1);
	245	return 0;
	246	}
	247
374330e2	248	static int do_ssh_init(void) {
	249	char c;
	250	char version[10];
	251	char vstring[40];
	252	int i;
	253
	254	#ifdef FWHACK
	255	i = 0;
	256	while (s_read(&c, 1) == 1) {
	257	if (c == 'S' && i < 2) i++;
	258	else if (c == 'S' && i == 2) i = 2;
	259	else if (c == 'H' && i == 2) break;
	260	else i = 0;
	261	}
	262	#else
	263	if (s_read(&c,1) != 1 \|\| c != 'S') return 0;
	264	if (s_read(&c,1) != 1 \|\| c != 'S') return 0;
	265	if (s_read(&c,1) != 1 \|\| c != 'H') return 0;
	266	#endif
	267	if (s_read(&c,1) != 1 \|\| c != '-') return 0;
	268	i = 0;
	269	while (1) {
	270	if (s_read(&c,1) != 1)
	271	return 0;
	272	if (i >= 0) {
	273	if (c == '-') {
	274	version[i] = '\0';
	275	i = -1;
	276	} else if (i < sizeof(version)-1)
	277	version[i++] = c;
	278	}
	279	else if (c == '\n')
	280	break;
	281	}
	282
9697bfd2	283	sprintf(vstring, "SSH-%s-PuTTY\n",
9697bfd2	284	(ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"));
374330e2	285	s_write(vstring, strlen(vstring));
fef97f43	286	return 1;
374330e2	287	}
	288
	289	static void ssh_protocol(unsigned char *in, int inlen, int ispkt) {
	290	int i, j, len;
	291	unsigned char session_id[16];
	292	unsigned char rsabuf, keystr1, *keystr2;
	293	unsigned char cookie[8];
	294	struct RSAKey servkey, hostkey;
	295	struct MD5Context md5c;
bea1ef5f	296	unsigned long supported_ciphers_mask;
bea1ef5f	297	int cipher_type;
374330e2	298
374330e2	299	extern struct ssh_cipher ssh_3des;
9697bfd2	300	extern struct ssh_cipher ssh_des;
bea1ef5f	301	extern struct ssh_cipher ssh_blowfish;
374330e2	302
	303	crBegin;
	304
	305	random_init();
	306
	307	while (!ispkt)
	308	crReturnV;
	309
972a41c8	310	if (pktin.type != SSH_SMSG_PUBLIC_KEY)
374330e2	311	fatalbox("Public key packet not received");
	312
	313	memcpy(cookie, pktin.body, 8);
	314
	315	MD5Init(&md5c);
	316
	317	i = makekey(pktin.body+8, &servkey, &keystr1);
	318
	319	j = makekey(pktin.body+8+i, &hostkey, &keystr2);
	320
bea1ef5f	321	supported_ciphers_mask = (pktin.body[12+i+j] << 24) \|
	322	(pktin.body[13+i+j] << 16) \|
	323	(pktin.body[14+i+j] << 8) \|
	324	(pktin.body[15+i+j]);
	325
374330e2	326	MD5Update(&md5c, keystr2, hostkey.bytes);
	327	MD5Update(&md5c, keystr1, servkey.bytes);
	328	MD5Update(&md5c, pktin.body, 8);
	329
	330	MD5Final(session_id, &md5c);
	331
	332	for (i=0; i<32; i++)
	333	session_key[i] = random_byte();
	334
	335	len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
	336
	337	rsabuf = malloc(len);
	338	if (!rsabuf)
	339	fatalbox("Out of memory");
	340
	341	verify_ssh_host_key(savedhost, &hostkey);
	342
	343	for (i=0; i<32; i++) {
	344	rsabuf[i] = session_key[i];
	345	if (i < 16)
	346	rsabuf[i] ^= session_id[i];
	347	}
	348
	349	if (hostkey.bytes > servkey.bytes) {
	350	rsaencrypt(rsabuf, 32, &servkey);
	351	rsaencrypt(rsabuf, servkey.bytes, &hostkey);
	352	} else {
	353	rsaencrypt(rsabuf, 32, &hostkey);
	354	rsaencrypt(rsabuf, hostkey.bytes, &servkey);
	355	}
	356
bea1ef5f	357	cipher_type = cfg.cipher == CIPHER_BLOWFISH ? SSH_CIPHER_BLOWFISH :
9697bfd2	358	cfg.cipher == CIPHER_DES ? SSH_CIPHER_DES :
bea1ef5f	359	SSH_CIPHER_3DES;
	360	if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
	361	c_write("Selected cipher not supported, falling back to 3DES\r\n", 53);
	362	cipher_type = SSH_CIPHER_3DES;
	363	}
	364
972a41c8	365	s_wrpkt_start(SSH_CMSG_SESSION_KEY, len+15);
bea1ef5f	366	pktout.body[0] = cipher_type;
374330e2	367	memcpy(pktout.body+1, cookie, 8);
	368	pktout.body[9] = (len*8) >> 8;
	369	pktout.body[10] = (len*8) & 0xFF;
	370	memcpy(pktout.body+11, rsabuf, len);
	371	pktout.body[len+11] = pktout.body[len+12] = 0; /* protocol flags */
	372	pktout.body[len+13] = pktout.body[len+14] = 0;
	373	s_wrpkt();
	374
	375	free(rsabuf);
	376
bea1ef5f	377	cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish :
9697bfd2	378	cipher_type == SSH_CIPHER_DES ? &ssh_des :
bea1ef5f	379	&ssh_3des;
374330e2	380	cipher->sesskey(session_key);
	381
	382	do { crReturnV; } while (!ispkt);
	383
972a41c8	384	if (pktin.type != SSH_SMSG_SUCCESS)
374330e2	385	fatalbox("Encryption not successfully enabled");
	386
	387	fflush(stdout);
	388	{
	389	static char username[100];
	390	static int pos = 0;
	391	static char c;
	392	if (!*cfg.username) {
	393	c_write("login as: ", 10);
	394	while (pos >= 0) {
	395	do { crReturnV; } while (ispkt);
	396	while (inlen--) switch (c = *in++) {
	397	case 10: case 13:
	398	username[pos] = 0;
	399	pos = -1;
	400	break;
	401	case 8: case 127:
	402	if (pos > 0) {
	403	c_write("\b \b", 3);
	404	pos--;
	405	}
	406	break;
	407	case 21: case 27:
	408	while (pos > 0) {
	409	c_write("\b \b", 3);
	410	pos--;
	411	}
	412	break;
	413	case 3: case 4:
	414	random_save_seed();
	415	exit(0);
	416	break;
	417	default:
	418	if (c >= ' ' && c <= '~' && pos < 40) {
	419	username[pos++] = c;
	420	c_write(&c, 1);
	421	}
	422	break;
	423	}
	424	}
	425	c_write("\r\n", 2);
	426	username[strcspn(username, "\n\r")] = '\0';
	427	} else {
	428	char stuff[200];
	429	strncpy(username, cfg.username, 99);
	430	username[99] = '\0';
	431	sprintf(stuff, "Sent username \"%s\".\r\n", username);
	432	c_write(stuff, strlen(stuff));
	433	}
972a41c8	434	s_wrpkt_start(SSH_CMSG_USER, 4+strlen(username));
374330e2	435	pktout.body[0] = pktout.body[1] = pktout.body[2] = 0;
	436	pktout.body[3] = strlen(username);
	437	memcpy(pktout.body+4, username, strlen(username));
	438	s_wrpkt();
	439	}
	440
	441	do { crReturnV; } while (!ispkt);
	442
972a41c8	443	while (pktin.type == SSH_SMSG_FAILURE) {
374330e2	444	static char password[100];
	445	static int pos;
	446	static char c;
	447	c_write("password: ", 10);
	448	pos = 0;
	449	while (pos >= 0) {
	450	do { crReturnV; } while (ispkt);
	451	while (inlen--) switch (c = *in++) {
	452	case 10: case 13:
	453	password[pos] = 0;
	454	pos = -1;
	455	break;
	456	case 8: case 127:
	457	if (pos > 0)
	458	pos--;
	459	break;
	460	case 21: case 27:
	461	pos = 0;
	462	break;
	463	case 3: case 4:
	464	random_save_seed();
	465	exit(0);
	466	break;
	467	default:
	468	if (c >= ' ' && c <= '~' && pos < 40)
	469	password[pos++] = c;
	470	break;
	471	}
	472	}
	473	c_write("\r\n", 2);
972a41c8	474	s_wrpkt_start(SSH_CMSG_AUTH_PASSWORD, 4+strlen(password));
374330e2	475	pktout.body[0] = pktout.body[1] = pktout.body[2] = 0;
	476	pktout.body[3] = strlen(password);
	477	memcpy(pktout.body+4, password, strlen(password));
	478	s_wrpkt();
	479	memset(password, 0, strlen(password));
	480	do { crReturnV; } while (!ispkt);
	481	if (pktin.type == 15) {
	482	c_write("Access denied\r\n", 15);
	483	} else if (pktin.type != 14) {
	484	fatalbox("Strange packet received, type %d", pktin.type);
	485	}
	486	}
	487
fef97f43	488	if (!cfg.nopty) {
fef97f43	489	i = strlen(cfg.termtype);
972a41c8	490	s_wrpkt_start(SSH_CMSG_REQUEST_PTY, i+5*4+1);
fef97f43	491	pktout.body[0] = (i >> 24) & 0xFF;
	492	pktout.body[1] = (i >> 16) & 0xFF;
	493	pktout.body[2] = (i >> 8) & 0xFF;
	494	pktout.body[3] = i & 0xFF;
	495	memcpy(pktout.body+4, cfg.termtype, i);
	496	i += 4;
	497	pktout.body[i++] = (rows >> 24) & 0xFF;
	498	pktout.body[i++] = (rows >> 16) & 0xFF;
	499	pktout.body[i++] = (rows >> 8) & 0xFF;
	500	pktout.body[i++] = rows & 0xFF;
	501	pktout.body[i++] = (cols >> 24) & 0xFF;
	502	pktout.body[i++] = (cols >> 16) & 0xFF;
	503	pktout.body[i++] = (cols >> 8) & 0xFF;
	504	pktout.body[i++] = cols & 0xFF;
	505	memset(pktout.body+i, 0, 9); /* 0 pixwidth, 0 pixheight, 0.b endofopt */
	506	s_wrpkt();
	507	ssh_state = SSH_STATE_INTERMED;
	508	do { crReturnV; } while (!ispkt);
972a41c8	509	if (pktin.type != SSH_MSG_SUCCESS && pktin.type != SSH_MSG_FAILURE) {
fef97f43	510	fatalbox("Protocol confusion");
972a41c8	511	} else if (pktin.type == SSH_MSG_FAILURE) {
fef97f43	512	c_write("Server refused to allocate pty\r\n", 32);
fef97f43	513	}
374330e2	514	}
374330e2	515
972a41c8	516	s_wrpkt_start(SSH_CMSG_EXEC_SHELL, 0);
374330e2	517	s_wrpkt();
	518
	519	ssh_state = SSH_STATE_SESSION;
	520	if (size_needed)
	521	ssh_size();
	522
	523	while (1) {
	524	crReturnV;
	525	if (ispkt) {
972a41c8	526	if (pktin.type == SSH_SMSG_STDOUT_DATA \|\|
972a41c8	527	pktin.type == SSH_SMSG_STDERR_DATA) {
374330e2	528	long len = 0;
	529	for (i = 0; i < 4; i++)
	530	len = (len << 8) + pktin.body[i];
	531	c_write(pktin.body+4, len);
972a41c8	532	} else if (pktin.type == SSH_MSG_DISCONNECT) {
21248260	533	ssh_state = SSH_STATE_CLOSED;
972a41c8	534	} else if (pktin.type == SSH_MSG_SUCCESS) {
	535	/* may be from EXEC_SHELL on some servers */
	536	} else if (pktin.type == SSH_MSG_FAILURE) {
	537	/* may be from EXEC_SHELL on some servers
374330e2	538	* if no pty is available or in other odd cases. Ignore */
972a41c8	539	} else if (pktin.type == SSH_SMSG_EXITSTATUS) {
972a41c8	540	s_wrpkt_start(SSH_CMSG_EXIT_CONFIRMATION, 0);
374330e2	541	s_wrpkt();
	542	} else {
	543	fatalbox("Strange packet received: type %d", pktin.type);
	544	}
	545	} else {
972a41c8	546	s_wrpkt_start(SSH_CMSG_STDIN_DATA, 4+inlen);
374330e2	547	pktout.body[0] = (inlen >> 24) & 0xFF;
	548	pktout.body[1] = (inlen >> 16) & 0xFF;
	549	pktout.body[2] = (inlen >> 8) & 0xFF;
	550	pktout.body[3] = inlen & 0xFF;
	551	memcpy(pktout.body+4, in, inlen);
	552	s_wrpkt();
	553	}
	554	}
	555
	556	crFinishV;
	557	}
	558
	559	/*
	560	* Called to set up the connection. Will arrange for WM_NETEVENT
	561	* messages to be passed to the specified window, whose window
	562	* procedure should then call telnet_msg().
	563	*
	564	* Returns an error message, or NULL on success.
	565	*
	566	* Also places the canonical host name into `realhost'.
	567	*/
	568	static char ssh_init (HWND hwnd, char host, int port, char **realhost) {
	569	SOCKADDR_IN addr;
	570	struct hostent *h;
	571	unsigned long a;
	572	#ifdef FWHACK
	573	char *FWhost;
	574	int FWport;
	575	#endif
	576
	577	savedhost = malloc(1+strlen(host));
	578	if (!savedhost)
	579	fatalbox("Out of memory");
	580	strcpy(savedhost, host);
	581
	582	#ifdef FWHACK
	583	FWhost = host;
	584	FWport = port;
	585	host = FWSTR;
	586	port = 23;
	587	#endif
	588
	589	/*
	590	* Try to find host.
	591	*/
	592	if ( (a = inet_addr(host)) == (unsigned long) INADDR_NONE) {
	593	if ( (h = gethostbyname(host)) == NULL)
	594	switch (WSAGetLastError()) {
	595	case WSAENETDOWN: return "Network is down";
	596	case WSAHOST_NOT_FOUND: case WSANO_DATA:
	597	return "Host does not exist";
	598	case WSATRY_AGAIN: return "Host not found";
	599	default: return "gethostbyname: unknown error";
	600	}
	601	memcpy (&a, h->h_addr, sizeof(a));
	602	*realhost = h->h_name;
	603	} else
	604	*realhost = host;
	605	#ifdef FWHACK
	606	*realhost = FWhost;
	607	#endif
	608	a = ntohl(a);
	609
	610	if (port < 0)
611	port = 22; /* default ssh port */
612
613	/*
614	* Open socket.
615	*/
616	s = socket(AF_INET, SOCK_STREAM, 0);
617	if (s == INVALID_SOCKET)
618	switch (WSAGetLastError()) {
619	case WSAENETDOWN: return "Network is down";
620	case WSAEAFNOSUPPORT: return "TCP/IP support not present";
621	default: return "socket(): unknown error";
622	}
623
624	/*
625	* Bind to local address.
626	*/
627	addr.sin_family = AF_INET;
628	addr.sin_addr.s_addr = htonl(INADDR_ANY);
629	addr.sin_port = htons(0);
630	if (bind (s, (struct sockaddr *)&addr, sizeof(addr)) == SOCKET_ERROR)
631	switch (WSAGetLastError()) {
632	case WSAENETDOWN: return "Network is down";
633	default: return "bind(): unknown error";
634	}
635
636	/*
637	* Connect to remote address.
638	*/
639	addr.sin_addr.s_addr = htonl(a);
640	addr.sin_port = htons((short)port);
641	if (connect (s, (struct sockaddr *)&addr, sizeof(addr)) == SOCKET_ERROR)
642	switch (WSAGetLastError()) {
643	case WSAENETDOWN: return "Network is down";
644	case WSAECONNREFUSED: return "Connection refused";
645	case WSAENETUNREACH: return "Network is unreachable";
646	case WSAEHOSTUNREACH: return "No route to host";
647	default: return "connect(): unknown error";
648	}
649
650	#ifdef FWHACK
651	send(s, "connect ", 8, 0);
652	send(s, FWhost, strlen(FWhost), 0);
653	{
654	char buf[20];
655	sprintf(buf, " %d\n", FWport);
656	send (s, buf, strlen(buf), 0);
657	}
658	#endif
659
660	if (!do_ssh_init())
661	return "Protocol initialisation error";
662
663	if (WSAAsyncSelect (s, hwnd, WM_NETEVENT, FD_READ \| FD_CLOSE) == SOCKET_ERROR)
664	switch (WSAGetLastError()) {
665	case WSAENETDOWN: return "Network is down";
666	default: return "WSAAsyncSelect(): unknown error";
667	}
668
669	return NULL;
670	}
671
672	/*
673	* Process a WM_NETEVENT message. Will return 0 if the connection
674	* has closed, or <0 for a socket error.
675	*/
676	static int ssh_msg (WPARAM wParam, LPARAM lParam) {
677	int ret;
678	char buf[256];
679
680	if (s == INVALID_SOCKET) /* how the hell did we get here?! */
681	return -5000;
682
683	if (WSAGETSELECTERROR(lParam) != 0)
684	return -WSAGETSELECTERROR(lParam);
685
686	switch (WSAGETSELECTEVENT(lParam)) {
687	case FD_READ:
688	ret = recv(s, buf, sizeof(buf), 0);
689	if (ret < 0 && WSAGetLastError() == WSAEWOULDBLOCK)
690	return 1;
691	if (ret < 0) /* any _other_ error */
692	return -10000-WSAGetLastError();
693	if (ret == 0) {
694	s = INVALID_SOCKET;
695	return 0; /* can't happen, in theory */
696	}
697	ssh_gotdata (buf, ret);
698	return 1;
699	case FD_CLOSE:
700	s = INVALID_SOCKET;
21248260	701	ssh_state = SSH_STATE_CLOSED;
374330e2	702	return 0;
	703	}
	704	return 1; /* shouldn't happen, but WTF */
	705	}
	706
	707	/*
	708	* Called to send data down the Telnet connection.
	709	*/
	710	static void ssh_send (char *buf, int len) {
	711	if (s == INVALID_SOCKET)
	712	return;
	713
	714	ssh_protocol(buf, len, 0);
	715	}
	716
	717	/*
	718	* Called to set the size of the window from Telnet's POV.
	719	*/
	720	static void ssh_size(void) {
	721	switch (ssh_state) {
	722	case SSH_STATE_BEFORE_SIZE:
21248260	723	case SSH_STATE_CLOSED:
374330e2	724	break; /* do nothing */
	725	case SSH_STATE_INTERMED:
	726	size_needed = TRUE; /* buffer for later */
	727	break;
	728	case SSH_STATE_SESSION:
fef97f43	729	if (!cfg.nopty) {
	730	s_wrpkt_start(11, 16);
	731	pktout.body[0] = (rows >> 24) & 0xFF;
	732	pktout.body[1] = (rows >> 16) & 0xFF;
	733	pktout.body[2] = (rows >> 8) & 0xFF;
	734	pktout.body[3] = rows & 0xFF;
	735	pktout.body[4] = (cols >> 24) & 0xFF;
	736	pktout.body[5] = (cols >> 16) & 0xFF;
	737	pktout.body[6] = (cols >> 8) & 0xFF;
	738	pktout.body[7] = cols & 0xFF;
	739	memset(pktout.body+8, 0, 8);
	740	s_wrpkt();
	741	}
374330e2	742	}
	743	}
	744
	745	/*
	746	* (Send Telnet special codes)
	747	*/
	748	static void ssh_special (Telnet_Special code) {
	749	/* do nothing */
	750	}
	751
	752	Backend ssh_backend = {
	753	ssh_init,
	754	ssh_msg,
	755	ssh_send,
	756	ssh_size,
	757	ssh_special
	758	};