diff options
Diffstat (limited to 'channels.c')
| -rw-r--r-- | channels.c | 61 |
1 files changed, 34 insertions, 27 deletions
@@ -39,7 +39,7 @@ */ #include "includes.h" -RCSID("$OpenBSD: channels.c,v 1.218 2005/07/01 13:19:47 markus Exp $"); +RCSID("$OpenBSD: channels.c,v 1.219 2005/07/04 00:58:42 djm Exp $"); #include "ssh.h" #include "ssh1.h" @@ -111,6 +111,9 @@ static int all_opens_permitted = 0; /* Maximum number of fake X11 displays to try. */ #define MAX_DISPLAYS 1000 +/* Saved X11 local (client) display. */ +static char *x11_saved_display = NULL; + /* Saved X11 authentication protocol name. */ static char *x11_saved_proto = NULL; @@ -2955,12 +2958,18 @@ x11_request_forwarding_with_spoofing(int client_session_id, const char *disp, const char *proto, const char *data) { u_int data_len = (u_int) strlen(data) / 2; - u_int i, value, len; + u_int i, value; char *new_data; int screen_number; const char *cp; u_int32_t rnd = 0; + if (x11_saved_display && strcmp(disp, x11_saved_display) != 0) { + error("x11_request_forwarding_with_spoofing: different " + "$DISPLAY already forwarded"); + return; + } + cp = disp; if (disp) cp = strchr(disp, ':'); @@ -2971,33 +2980,31 @@ x11_request_forwarding_with_spoofing(int client_session_id, const char *disp, else screen_number = 0; - /* Save protocol name. */ - x11_saved_proto = xstrdup(proto); - - /* - * Extract real authentication data and generate fake data of the - * same length. - */ - x11_saved_data = xmalloc(data_len); - x11_fake_data = xmalloc(data_len); - for (i = 0; i < data_len; i++) { - if (sscanf(data + 2 * i, "%2x", &value) != 1) - fatal("x11_request_forwarding: bad authentication data: %.100s", data); - if (i % 4 == 0) - rnd = arc4random(); - x11_saved_data[i] = value; - x11_fake_data[i] = rnd & 0xff; - rnd >>= 8; - } - x11_saved_data_len = data_len; - x11_fake_data_len = data_len; + if (x11_saved_proto == NULL) { + /* Save protocol name. */ + x11_saved_proto = xstrdup(proto); + /* + * Extract real authentication data and generate fake data + * of the same length. + */ + x11_saved_data = xmalloc(data_len); + x11_fake_data = xmalloc(data_len); + for (i = 0; i < data_len; i++) { + if (sscanf(data + 2 * i, "%2x", &value) != 1) + fatal("x11_request_forwarding: bad " + "authentication data: %.100s", data); + if (i % 4 == 0) + rnd = arc4random(); + x11_saved_data[i] = value; + x11_fake_data[i] = rnd & 0xff; + rnd >>= 8; + } + x11_saved_data_len = data_len; + x11_fake_data_len = data_len; + } /* Convert the fake data into hex. */ - len = 2 * data_len + 1; - new_data = xmalloc(len); - for (i = 0; i < data_len; i++) - snprintf(new_data + 2 * i, len - 2 * i, - "%02x", (u_char) x11_fake_data[i]); + new_data = tohex(x11_fake_data, data_len); /* Send the request packet. */ if (compat20) { |