[u/mdw/putty] / x11fwd.c

#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include <time.h>

#include "putty.h"
#include "ssh.h"

#define GET_32BIT_LSB_FIRST(cp) \
  (((unsigned long)(unsigned char)(cp)[0]) | \
  ((unsigned long)(unsigned char)(cp)[1] << 8) | \
  ((unsigned long)(unsigned char)(cp)[2] << 16) | \
  ((unsigned long)(unsigned char)(cp)[3] << 24))

#define PUT_32BIT_LSB_FIRST(cp, value) ( \
  (cp)[0] = (value), \
  (cp)[1] = (value) >> 8, \
  (cp)[2] = (value) >> 16, \
  (cp)[3] = (value) >> 24 )

#define GET_16BIT_LSB_FIRST(cp) \
  (((unsigned long)(unsigned char)(cp)[0]) | \
  ((unsigned long)(unsigned char)(cp)[1] << 8))

#define PUT_16BIT_LSB_FIRST(cp, value) ( \
  (cp)[0] = (value), \
  (cp)[1] = (value) >> 8 )

#define GET_32BIT_MSB_FIRST(cp) \
  (((unsigned long)(unsigned char)(cp)[0] << 24) | \
  ((unsigned long)(unsigned char)(cp)[1] << 16) | \
  ((unsigned long)(unsigned char)(cp)[2] << 8) | \
  ((unsigned long)(unsigned char)(cp)[3]))

#define PUT_32BIT_MSB_FIRST(cp, value) ( \
  (cp)[0] = (value) >> 24, \
  (cp)[1] = (value) >> 16, \
  (cp)[2] = (value) >> 8, \
  (cp)[3] = (value) )

#define GET_16BIT_MSB_FIRST(cp) \
  (((unsigned long)(unsigned char)(cp)[0] << 8) | \
  ((unsigned long)(unsigned char)(cp)[1]))

#define PUT_16BIT_MSB_FIRST(cp, value) ( \
  (cp)[0] = (value) >> 8, \
  (cp)[1] = (value) )

#define GET_16BIT(endian, cp) \
  (endian=='B' ? GET_16BIT_MSB_FIRST(cp) : GET_16BIT_LSB_FIRST(cp))

#define PUT_16BIT(endian, cp, val) \
  (endian=='B' ? PUT_16BIT_MSB_FIRST(cp, val) : PUT_16BIT_LSB_FIRST(cp, val))

const char *const x11_authnames[] = {
    "", "MIT-MAGIC-COOKIE-1", "XDM-AUTHORIZATION-1"
};

struct X11Auth {
    unsigned char fakedata[64], realdata[64];
    int fakeproto, realproto;
    int fakelen, reallen;
};

struct X11Private {
    const struct plug_function_table *fn;
    /* the above variable absolutely *must* be the first in this structure */
    unsigned char firstpkt[12];	       /* first X data packet */
    struct X11Auth *auth;
    char *auth_protocol;
    unsigned char *auth_data;
    int data_read, auth_plen, auth_psize, auth_dlen, auth_dsize;
    int verified;
    int throttled, throttle_override;
    void *c;			       /* data used by ssh.c */
    Socket s;
};

void *x11_invent_auth(char *proto, int protomaxlen,
		     char *data, int datamaxlen)
{
    struct X11Auth *auth = smalloc(sizeof(struct X11Auth));
    char ourdata[64];
    int i;

    auth->fakeproto = X11_MIT;

    /* MIT-MAGIC-COOKIE-1. Cookie size is 128 bits (16 bytes). */
    auth->fakelen = 16;
    for (i = 0; i < 16; i++)
	auth->fakedata[i] = random_byte();

    /* Now format for the recipient. */
    strncpy(proto, x11_authnames[auth->fakeproto], protomaxlen);
    ourdata[0] = '\0';
    for (i = 0; i < auth->fakelen; i++)
	sprintf(ourdata + strlen(ourdata), "%02x", auth->fakedata[i]);
    strncpy(data, ourdata, datamaxlen);

    return auth;
}

/*
 * Fetch the real auth data for a given display string, and store
 * it in an X11Auth structure. Returns NULL on success, or an error
 * string.
 */
void x11_get_real_auth(void *authv, char *display)
{
    struct X11Auth *auth = (struct X11Auth *)authv;

    auth->realproto = X11_NO_AUTH;     /* in case next call does nothing */

    auth->reallen = sizeof(auth->realdata);
    platform_get_x11_auth(display, &auth->realproto,
                          auth->realdata, &auth->reallen);
}

static int x11_verify(struct X11Auth *auth,
		      char *proto, unsigned char *data, int dlen)
{
    if (strcmp(proto, x11_authnames[auth->fakeproto]) != 0)
	return 0;		       /* wrong protocol attempted */
    if (auth->fakeproto == X11_MIT) {
        if (dlen != auth->fakelen)
            return 0;		       /* cookie was wrong length */
        if (memcmp(auth->fakedata, data, dlen) != 0)
            return 0;		       /* cookie was wrong cookie! */
    }
    /* implement other protocols here if ever required */
    return 1;
}

static int x11_closing(Plug plug, char *error_msg, int error_code,
		       int calling_back)
{
    struct X11Private *pr = (struct X11Private *) plug;

    /*
     * We have no way to communicate down the forwarded connection,
     * so if an error occurred on the socket, we just ignore it
     * and treat it like a proper close.
     */
    sshfwd_close(pr->c);
    x11_close(pr->s);
    return 1;
}

static int x11_receive(Plug plug, int urgent, char *data, int len)
{
    struct X11Private *pr = (struct X11Private *) plug;

    if (sshfwd_write(pr->c, data, len) > 0) {
	pr->throttled = 1;
	sk_set_frozen(pr->s, 1);
    }

    return 1;
}

static void x11_sent(Plug plug, int bufsize)
{
    struct X11Private *pr = (struct X11Private *) plug;

    sshfwd_unthrottle(pr->c, bufsize);
}

/*
 * When setting up X forwarding, we should send the screen number
 * from the specified local display. This function extracts it from
 * the display string.
 */
int x11_get_screen_number(char *display)
{
    int n;

    n = strcspn(display, ":");
    if (!display[n])
	return 0;
    n = strcspn(display, ".");
    if (!display[n])
	return 0;
    return atoi(display + n + 1);
}

/*
 * Called to set up the raw connection.
 * 
 * Returns an error message, or NULL on success.
 * also, fills the SocketsStructure
 */
char *x11_init(Socket * s, char *display, void *c, void *auth)
{
    static const struct plug_function_table fn_table = {
	x11_closing,
	x11_receive,
	x11_sent,
	NULL
    };

    SockAddr addr;
    int port;
    char *err, *dummy_realhost;
    char host[128];
    int n, displaynum;
    struct X11Private *pr;

    /*
     * Split up display name into host and display-number parts.
     */
    n = strcspn(display, ":");
    if (display[n])
	displaynum = atoi(display + n + 1);
    else
	displaynum = 0;		       /* sensible default */
    if (n > sizeof(host) - 1)
	n = sizeof(host) - 1;
    if (n > 0) {
	strncpy(host, display, n);
	host[n] = '\0';
    } else {
	/*
	 * Local display numbers, particularly on Unix, often omit
	 * the display part completely.
	 */
	strcpy(host, "localhost");
    }

    port = 6000 + displaynum;

    /*
     * Try to find host.
     */
    addr = name_lookup(host, port, &dummy_realhost);
    if ((err = sk_addr_error(addr)) != NULL)
	return err;

    /*
     * Open socket.
     */
    pr = (struct X11Private *) smalloc(sizeof(struct X11Private));
    pr->fn = &fn_table;
    pr->auth_protocol = NULL;
    pr->auth = (struct X11Auth *)auth;
    pr->verified = 0;
    pr->data_read = 0;
    pr->throttled = pr->throttle_override = 0;
    pr->c = c;

    pr->s = *s = new_connection(addr, dummy_realhost, port, 0, 1, 0, (Plug) pr);
    if ((err = sk_socket_error(*s)) != NULL) {
	sfree(pr);
	return err;
    }

    sk_set_private_ptr(*s, pr);
    sk_addr_free(addr);
    return NULL;
}

void x11_close(Socket s)
{
    struct X11Private *pr;
    if (!s)
	return;
    pr = (struct X11Private *) sk_get_private_ptr(s);
    if (pr->auth_protocol) {
	sfree(pr->auth_protocol);
	sfree(pr->auth_data);
    }

    sfree(pr);

    sk_close(s);
}

void x11_unthrottle(Socket s)
{
    struct X11Private *pr;
    if (!s)
	return;
    pr = (struct X11Private *) sk_get_private_ptr(s);

    pr->throttled = 0;
    sk_set_frozen(s, pr->throttled || pr->throttle_override);
}

void x11_override_throttle(Socket s, int enable)
{
    struct X11Private *pr;
    if (!s)
	return;
    pr = (struct X11Private *) sk_get_private_ptr(s);

    pr->throttle_override = enable;
    sk_set_frozen(s, pr->throttled || pr->throttle_override);
}

/*
 * Called to send data down the raw connection.
 */
int x11_send(Socket s, char *data, int len)
{
    struct X11Private *pr = (struct X11Private *) sk_get_private_ptr(s);

    if (s == NULL)
	return 0;

    /*
     * Read the first packet.
     */
    while (len > 0 && pr->data_read < 12)
	pr->firstpkt[pr->data_read++] = (unsigned char) (len--, *data++);
    if (pr->data_read < 12)
	return 0;

    /*
     * If we have not allocated the auth_protocol and auth_data
     * strings, do so now.
     */
    if (!pr->auth_protocol) {
	pr->auth_plen = GET_16BIT(pr->firstpkt[0], pr->firstpkt + 6);
	pr->auth_dlen = GET_16BIT(pr->firstpkt[0], pr->firstpkt + 8);
	pr->auth_psize = (pr->auth_plen + 3) & ~3;
	pr->auth_dsize = (pr->auth_dlen + 3) & ~3;
	/* Leave room for a terminating zero, to make our lives easier. */
	pr->auth_protocol = (char *) smalloc(pr->auth_psize + 1);
	pr->auth_data = (unsigned char *) smalloc(pr->auth_dsize);
    }

    /*
     * Read the auth_protocol and auth_data strings.
     */
    while (len > 0 && pr->data_read < 12 + pr->auth_psize)
	pr->auth_protocol[pr->data_read++ - 12] = (len--, *data++);
    while (len > 0 && pr->data_read < 12 + pr->auth_psize + pr->auth_dsize)
	pr->auth_data[pr->data_read++ - 12 -
		      pr->auth_psize] = (unsigned char) (len--, *data++);
    if (pr->data_read < 12 + pr->auth_psize + pr->auth_dsize)
	return 0;

    /*
     * If we haven't verified the authentication, do so now.
     */
    if (!pr->verified) {
	int ret;

	pr->auth_protocol[pr->auth_plen] = '\0';	/* ASCIZ */
	ret = x11_verify(pr->auth, pr->auth_protocol,
			 pr->auth_data, pr->auth_dlen);

	/*
	 * If authentication failed, construct and send an error
	 * packet, then terminate the connection.
	 */
	if (!ret) {
	    char message[] = "Authentication failed at PuTTY X11 proxy";
	    unsigned char reply[8 + sizeof(message) + 4];
	    int msglen = sizeof(message) - 1;	/* skip zero byte */
	    int msgsize = (msglen + 3) & ~3;
	    reply[0] = 0;	       /* failure */
	    reply[1] = msglen;	       /* length of reason string */
	    memcpy(reply + 2, pr->firstpkt + 2, 4);	/* major/minor proto vsn */
	    PUT_16BIT(pr->firstpkt[0], reply + 6, msgsize >> 2);/* data len */
	    memset(reply + 8, 0, msgsize);
	    memcpy(reply + 8, message, msglen);
	    sshfwd_write(pr->c, (char *)reply, 8 + msgsize);
	    sshfwd_close(pr->c);
	    x11_close(s);
	    return 0;
	}

	/*
	 * Now we know we're going to accept the connection. Strip
	 * the fake auth data, and optionally put real auth data in
	 * instead.
	 */
        {
            char realauthdata[64];
            int realauthlen = 0;
            int authstrlen = strlen(x11_authnames[pr->auth->realproto]);
	    unsigned long ip;
	    int port;
            static const char zeroes[4] = { 0,0,0,0 };

            if (pr->auth->realproto == X11_MIT) {
                assert(pr->auth->reallen <= lenof(realauthdata));
                realauthlen = pr->auth->reallen;
                memcpy(realauthdata, pr->auth->realdata, realauthlen);
            } else if (pr->auth->realproto == X11_XDM &&
		       pr->auth->reallen == 16 &&
		       sk_getxdmdata(s, &ip, &port)) {
		time_t t;
                realauthlen = 24;
		memset(realauthdata, 0, 24);
		memcpy(realauthdata, pr->auth->realdata, 8);
		PUT_32BIT_MSB_FIRST(realauthdata+8, ip);
		PUT_16BIT_MSB_FIRST(realauthdata+12, port);
		t = time(NULL);
		PUT_32BIT_MSB_FIRST(realauthdata+14, t);
		des_encrypt_xdmauth(pr->auth->realdata+9,
				    (unsigned char *)realauthdata, 24);
	    }
            /* implement other auth methods here if required */

            PUT_16BIT(pr->firstpkt[0], pr->firstpkt + 6, authstrlen);
            PUT_16BIT(pr->firstpkt[0], pr->firstpkt + 8, realauthlen);
        
            sk_write(s, (char *)pr->firstpkt, 12);

            if (authstrlen) {
                sk_write(s, x11_authnames[pr->auth->realproto], authstrlen);
                sk_write(s, zeroes, 3 & (-authstrlen));
            }
            if (realauthlen) {
                sk_write(s, realauthdata, realauthlen);
                sk_write(s, zeroes, 3 & (-realauthlen));
            }
        }
	pr->verified = 1;
    }

    /*
     * After initialisation, just copy data simply.
     */

    return sk_write(s, data, len);
}
Commit	Line	Data
9c964e85	1	#include <stdio.h>
9c964e85	2	#include <stdlib.h>
e0e7dff8	3	#include <assert.h>
2f92b717	4	#include <time.h>
9c964e85	5
	6	#include "putty.h"
	7	#include "ssh.h"
	8
9c964e85	9	#define GET_32BIT_LSB_FIRST(cp) \
	10	(((unsigned long)(unsigned char)(cp)[0]) \| \
	11	((unsigned long)(unsigned char)(cp)[1] << 8) \| \
	12	((unsigned long)(unsigned char)(cp)[2] << 16) \| \
	13	((unsigned long)(unsigned char)(cp)[3] << 24))
	14
	15	#define PUT_32BIT_LSB_FIRST(cp, value) ( \
	16	(cp)[0] = (value), \
	17	(cp)[1] = (value) >> 8, \
	18	(cp)[2] = (value) >> 16, \
	19	(cp)[3] = (value) >> 24 )
	20
	21	#define GET_16BIT_LSB_FIRST(cp) \
	22	(((unsigned long)(unsigned char)(cp)[0]) \| \
	23	((unsigned long)(unsigned char)(cp)[1] << 8))
	24
	25	#define PUT_16BIT_LSB_FIRST(cp, value) ( \
	26	(cp)[0] = (value), \
	27	(cp)[1] = (value) >> 8 )
	28
	29	#define GET_32BIT_MSB_FIRST(cp) \
	30	(((unsigned long)(unsigned char)(cp)[0] << 24) \| \
	31	((unsigned long)(unsigned char)(cp)[1] << 16) \| \
	32	((unsigned long)(unsigned char)(cp)[2] << 8) \| \
	33	((unsigned long)(unsigned char)(cp)[3]))
	34
	35	#define PUT_32BIT_MSB_FIRST(cp, value) ( \
	36	(cp)[0] = (value) >> 24, \
	37	(cp)[1] = (value) >> 16, \
	38	(cp)[2] = (value) >> 8, \
	39	(cp)[3] = (value) )
	40
	41	#define GET_16BIT_MSB_FIRST(cp) \
	42	(((unsigned long)(unsigned char)(cp)[0] << 8) \| \
	43	((unsigned long)(unsigned char)(cp)[1]))
	44
	45	#define PUT_16BIT_MSB_FIRST(cp, value) ( \
	46	(cp)[0] = (value) >> 8, \
	47	(cp)[1] = (value) )
	48
	49	#define GET_16BIT(endian, cp) \
	50	(endian=='B' ? GET_16BIT_MSB_FIRST(cp) : GET_16BIT_LSB_FIRST(cp))
	51
	52	#define PUT_16BIT(endian, cp, val) \
	53	(endian=='B' ? PUT_16BIT_MSB_FIRST(cp, val) : PUT_16BIT_LSB_FIRST(cp, val))
	54
e0e7dff8	55	const char *const x11_authnames[] = {
2f92b717	56	"", "MIT-MAGIC-COOKIE-1", "XDM-AUTHORIZATION-1"
e0e7dff8	57	};
e0e7dff8	58
302121de	59	struct X11Auth {
e0e7dff8	60	unsigned char fakedata[64], realdata[64];
	61	int fakeproto, realproto;
	62	int fakelen, reallen;
302121de	63	};
302121de	64
9c964e85	65	struct X11Private {
302121de	66	const struct plug_function_table *fn;
7e78000d	67	/* the above variable absolutely must be the first in this structure */
32874aea	68	unsigned char firstpkt[12]; /* first X data packet */
302121de	69	struct X11Auth *auth;
9c964e85	70	char *auth_protocol;
	71	unsigned char *auth_data;
	72	int data_read, auth_plen, auth_psize, auth_dlen, auth_dsize;
	73	int verified;
5471d09a	74	int throttled, throttle_override;
32874aea	75	void c; / data used by ssh.c */
7e78000d	76	Socket s;
9c964e85	77	};
9c964e85	78
302121de	79	void x11_invent_auth(char proto, int protomaxlen,
32874aea	80	char *data, int datamaxlen)
32874aea	81	{
302121de	82	struct X11Auth *auth = smalloc(sizeof(struct X11Auth));
9c964e85	83	char ourdata[64];
	84	int i;
	85
e0e7dff8	86	auth->fakeproto = X11_MIT;
e0e7dff8	87
9c964e85	88	/* MIT-MAGIC-COOKIE-1. Cookie size is 128 bits (16 bytes). */
e0e7dff8	89	auth->fakelen = 16;
9c964e85	90	for (i = 0; i < 16; i++)
e0e7dff8	91	auth->fakedata[i] = random_byte();
9c964e85	92
9c964e85	93	/* Now format for the recipient. */
e0e7dff8	94	strncpy(proto, x11_authnames[auth->fakeproto], protomaxlen);
9c964e85	95	ourdata[0] = '\0';
e0e7dff8	96	for (i = 0; i < auth->fakelen; i++)
e0e7dff8	97	sprintf(ourdata + strlen(ourdata), "%02x", auth->fakedata[i]);
9c964e85	98	strncpy(data, ourdata, datamaxlen);
302121de	99
302121de	100	return auth;
9c964e85	101	}
9c964e85	102
e0e7dff8	103	/*
	104	* Fetch the real auth data for a given display string, and store
	105	* it in an X11Auth structure. Returns NULL on success, or an error
	106	* string.
	107	*/
	108	void x11_get_real_auth(void authv, char display)
	109	{
	110	struct X11Auth auth = (struct X11Auth )authv;
	111
	112	auth->realproto = X11_NO_AUTH; /* in case next call does nothing */
	113
	114	auth->reallen = sizeof(auth->realdata);
	115	platform_get_x11_auth(display, &auth->realproto,
	116	auth->realdata, &auth->reallen);
	117	}
	118
302121de	119	static int x11_verify(struct X11Auth *auth,
302121de	120	char proto, unsigned char data, int dlen)
32874aea	121	{
e0e7dff8	122	if (strcmp(proto, x11_authnames[auth->fakeproto]) != 0)
32874aea	123	return 0; /* wrong protocol attempted */
e0e7dff8	124	if (auth->fakeproto == X11_MIT) {
	125	if (dlen != auth->fakelen)
	126	return 0; /* cookie was wrong length */
	127	if (memcmp(auth->fakedata, data, dlen) != 0)
	128	return 0; /* cookie was wrong cookie! */
	129	}
	130	/* implement other protocols here if ever required */
9c964e85	131	return 1;
	132	}
	133
32874aea	134	static int x11_closing(Plug plug, char *error_msg, int error_code,
	135	int calling_back)
	136	{
7e78000d	137	struct X11Private pr = (struct X11Private ) plug;
	138
	139	/*
	140	* We have no way to communicate down the forwarded connection,
	141	* so if an error occurred on the socket, we just ignore it
	142	* and treat it like a proper close.
	143	*/
	144	sshfwd_close(pr->c);
	145	x11_close(pr->s);
	146	return 1;
	147	}
	148
32874aea	149	static int x11_receive(Plug plug, int urgent, char *data, int len)
32874aea	150	{
7e78000d	151	struct X11Private pr = (struct X11Private ) plug;
9c964e85	152
5471d09a	153	if (sshfwd_write(pr->c, data, len) > 0) {
	154	pr->throttled = 1;
	155	sk_set_frozen(pr->s, 1);
	156	}
	157
9c964e85	158	return 1;
	159	}
	160
5471d09a	161	static void x11_sent(Plug plug, int bufsize)
	162	{
	163	struct X11Private pr = (struct X11Private ) plug;
	164
	165	sshfwd_unthrottle(pr->c, bufsize);
	166	}
	167
9c964e85	168	/*
421d6835	169	* When setting up X forwarding, we should send the screen number
	170	* from the specified local display. This function extracts it from
	171	* the display string.
	172	*/
	173	int x11_get_screen_number(char *display)
	174	{
	175	int n;
	176
	177	n = strcspn(display, ":");
	178	if (!display[n])
	179	return 0;
	180	n = strcspn(display, ".");
	181	if (!display[n])
	182	return 0;
	183	return atoi(display + n + 1);
	184	}
	185
	186	/*
9c964e85	187	* Called to set up the raw connection.
	188	*
	189	* Returns an error message, or NULL on success.
	190	* also, fills the SocketsStructure
9c964e85	191	*/
302121de	192	char x11_init(Socket s, char display, void c, void *auth)
32874aea	193	{
302121de	194	static const struct plug_function_table fn_table = {
7e78000d	195	x11_closing,
5471d09a	196	x11_receive,
	197	x11_sent,
	198	NULL
7e78000d	199	};
7e78000d	200
9c964e85	201	SockAddr addr;
9c964e85	202	int port;
0c6c9a70	203	char err, dummy_realhost;
9c964e85	204	char host[128];
	205	int n, displaynum;
	206	struct X11Private *pr;
	207
	208	/*
	209	* Split up display name into host and display-number parts.
	210	*/
	211	n = strcspn(display, ":");
	212	if (display[n])
32874aea	213	displaynum = atoi(display + n + 1);
9c964e85	214	else
32874aea	215	displaynum = 0; /* sensible default */
	216	if (n > sizeof(host) - 1)
	217	n = sizeof(host) - 1;
ecc0ba5b	218	if (n > 0) {
	219	strncpy(host, display, n);
	220	host[n] = '\0';
	221	} else {
	222	/*
	223	* Local display numbers, particularly on Unix, often omit
	224	* the display part completely.
	225	*/
	226	strcpy(host, "localhost");
	227	}
9c964e85	228
9f2f8ea0	229	port = 6000 + displaynum;
9f2f8ea0	230
9c964e85	231	/*
	232	* Try to find host.
	233	*/
b7a189f3	234	addr = name_lookup(host, port, &dummy_realhost);
6518ea7b	235	if ((err = sk_addr_error(addr)) != NULL)
9c964e85	236	return err;
9c964e85	237
9c964e85	238	/*
	239	* Open socket.
	240	*/
32874aea	241	pr = (struct X11Private *) smalloc(sizeof(struct X11Private));
7e78000d	242	pr->fn = &fn_table;
9c964e85	243	pr->auth_protocol = NULL;
302121de	244	pr->auth = (struct X11Auth *)auth;
9c964e85	245	pr->verified = 0;
9c964e85	246	pr->data_read = 0;
5471d09a	247	pr->throttled = pr->throttle_override = 0;
9c964e85	248	pr->c = c;
9c964e85	249
8eebd221	250	pr->s = *s = new_connection(addr, dummy_realhost, port, 0, 1, 0, (Plug) pr);
6518ea7b	251	if ((err = sk_socket_error(*s)) != NULL) {
32874aea	252	sfree(pr);
7e78000d	253	return err;
	254	}
	255
9c964e85	256	sk_set_private_ptr(*s, pr);
	257	sk_addr_free(addr);
	258	return NULL;
	259	}
	260
32874aea	261	void x11_close(Socket s)
	262	{
	263	struct X11Private *pr;
d74d141c	264	if (!s)
	265	return;
	266	pr = (struct X11Private *) sk_get_private_ptr(s);
9c964e85	267	if (pr->auth_protocol) {
32874aea	268	sfree(pr->auth_protocol);
32874aea	269	sfree(pr->auth_data);
9c964e85	270	}
	271
	272	sfree(pr);
	273
	274	sk_close(s);
	275	}
	276
5471d09a	277	void x11_unthrottle(Socket s)
	278	{
	279	struct X11Private *pr;
	280	if (!s)
	281	return;
	282	pr = (struct X11Private *) sk_get_private_ptr(s);
	283
	284	pr->throttled = 0;
	285	sk_set_frozen(s, pr->throttled \|\| pr->throttle_override);
	286	}
	287
	288	void x11_override_throttle(Socket s, int enable)
	289	{
	290	struct X11Private *pr;
	291	if (!s)
	292	return;
	293	pr = (struct X11Private *) sk_get_private_ptr(s);
	294
	295	pr->throttle_override = enable;
	296	sk_set_frozen(s, pr->throttled \|\| pr->throttle_override);
	297	}
	298
9c964e85	299	/*
	300	* Called to send data down the raw connection.
	301	*/
5471d09a	302	int x11_send(Socket s, char *data, int len)
32874aea	303	{
32874aea	304	struct X11Private pr = (struct X11Private ) sk_get_private_ptr(s);
9c964e85	305
9c964e85	306	if (s == NULL)
5471d09a	307	return 0;
9c964e85	308
	309	/*
	310	* Read the first packet.
	311	*/
	312	while (len > 0 && pr->data_read < 12)
32874aea	313	pr->firstpkt[pr->data_read++] = (unsigned char) (len--, *data++);
9c964e85	314	if (pr->data_read < 12)
5471d09a	315	return 0;
9c964e85	316
	317	/*
	318	* If we have not allocated the auth_protocol and auth_data
	319	* strings, do so now.
	320	*/
	321	if (!pr->auth_protocol) {
32874aea	322	pr->auth_plen = GET_16BIT(pr->firstpkt[0], pr->firstpkt + 6);
	323	pr->auth_dlen = GET_16BIT(pr->firstpkt[0], pr->firstpkt + 8);
	324	pr->auth_psize = (pr->auth_plen + 3) & ~3;
	325	pr->auth_dsize = (pr->auth_dlen + 3) & ~3;
	326	/* Leave room for a terminating zero, to make our lives easier. */
	327	pr->auth_protocol = (char *) smalloc(pr->auth_psize + 1);
f28e6b7c	328	pr->auth_data = (unsigned char *) smalloc(pr->auth_dsize);
9c964e85	329	}
	330
	331	/*
	332	* Read the auth_protocol and auth_data strings.
	333	*/
	334	while (len > 0 && pr->data_read < 12 + pr->auth_psize)
32874aea	335	pr->auth_protocol[pr->data_read++ - 12] = (len--, *data++);
9c964e85	336	while (len > 0 && pr->data_read < 12 + pr->auth_psize + pr->auth_dsize)
32874aea	337	pr->auth_data[pr->data_read++ - 12 -
32874aea	338	pr->auth_psize] = (unsigned char) (len--, *data++);
9c964e85	339	if (pr->data_read < 12 + pr->auth_psize + pr->auth_dsize)
5471d09a	340	return 0;
9c964e85	341
	342	/*
	343	* If we haven't verified the authentication, do so now.
	344	*/
	345	if (!pr->verified) {
32874aea	346	int ret;
	347
	348	pr->auth_protocol[pr->auth_plen] = '\0'; /* ASCIZ */
302121de	349	ret = x11_verify(pr->auth, pr->auth_protocol,
302121de	350	pr->auth_data, pr->auth_dlen);
32874aea	351
	352	/*
	353	* If authentication failed, construct and send an error
	354	* packet, then terminate the connection.
	355	*/
	356	if (!ret) {
	357	char message[] = "Authentication failed at PuTTY X11 proxy";
	358	unsigned char reply[8 + sizeof(message) + 4];
	359	int msglen = sizeof(message) - 1; /* skip zero byte */
	360	int msgsize = (msglen + 3) & ~3;
	361	reply[0] = 0; /* failure */
	362	reply[1] = msglen; /* length of reason string */
	363	memcpy(reply + 2, pr->firstpkt + 2, 4); /* major/minor proto vsn */
75105663	364	PUT_16BIT(pr->firstpkt[0], reply + 6, msgsize >> 2);/* data len */
32874aea	365	memset(reply + 8, 0, msgsize);
32874aea	366	memcpy(reply + 8, message, msglen);
f28e6b7c	367	sshfwd_write(pr->c, (char *)reply, 8 + msgsize);
32874aea	368	sshfwd_close(pr->c);
32874aea	369	x11_close(s);
5471d09a	370	return 0;
32874aea	371	}
	372
	373	/*
	374	* Now we know we're going to accept the connection. Strip
e0e7dff8	375	* the fake auth data, and optionally put real auth data in
e0e7dff8	376	* instead.
32874aea	377	*/
e0e7dff8	378	{
	379	char realauthdata[64];
	380	int realauthlen = 0;
	381	int authstrlen = strlen(x11_authnames[pr->auth->realproto]);
2f92b717	382	unsigned long ip;
2f92b717	383	int port;
e0e7dff8	384	static const char zeroes[4] = { 0,0,0,0 };
	385
	386	if (pr->auth->realproto == X11_MIT) {
	387	assert(pr->auth->reallen <= lenof(realauthdata));
	388	realauthlen = pr->auth->reallen;
	389	memcpy(realauthdata, pr->auth->realdata, realauthlen);
2f92b717	390	} else if (pr->auth->realproto == X11_XDM &&
	391	pr->auth->reallen == 16 &&
	392	sk_getxdmdata(s, &ip, &port)) {
	393	time_t t;
	394	realauthlen = 24;
	395	memset(realauthdata, 0, 24);
	396	memcpy(realauthdata, pr->auth->realdata, 8);
	397	PUT_32BIT_MSB_FIRST(realauthdata+8, ip);
	398	PUT_16BIT_MSB_FIRST(realauthdata+12, port);
	399	t = time(NULL);
	400	PUT_32BIT_MSB_FIRST(realauthdata+14, t);
6e7f5aee	401	des_encrypt_xdmauth(pr->auth->realdata+9,
6e7f5aee	402	(unsigned char *)realauthdata, 24);
2f92b717	403	}
e0e7dff8	404	/* implement other auth methods here if required */
	405
	406	PUT_16BIT(pr->firstpkt[0], pr->firstpkt + 6, authstrlen);
	407	PUT_16BIT(pr->firstpkt[0], pr->firstpkt + 8, realauthlen);
	408
	409	sk_write(s, (char *)pr->firstpkt, 12);
	410
	411	if (authstrlen) {
	412	sk_write(s, x11_authnames[pr->auth->realproto], authstrlen);
	413	sk_write(s, zeroes, 3 & (-authstrlen));
	414	}
	415	if (realauthlen) {
	416	sk_write(s, realauthdata, realauthlen);
	417	sk_write(s, zeroes, 3 & (-realauthlen));
	418	}
	419	}
32874aea	420	pr->verified = 1;
9c964e85	421	}
	422
	423	/*
	424	* After initialisation, just copy data simply.
	425	*/
	426
5471d09a	427	return sk_write(s, data, len);
9c964e85	428	}