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387 lines
12 KiB
387 lines
12 KiB
From f98a09cacff7baad8748c9aa217afd155a4d493f Mon Sep 17 00:00:00 2001 |
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From: "mmcc@openbsd.org" <mmcc@openbsd.org> |
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Date: Tue, 20 Oct 2015 03:36:35 +0000 |
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Subject: upstream commit |
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Replace a function-local allocation with stack memory. |
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ok djm@ |
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Upstream-ID: c09fbbab637053a2ab9f33ca142b4e20a4c5a17e |
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--- |
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clientloop.c | 9 ++------- |
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1 file changed, 2 insertions(+), 7 deletions(-) |
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diff --git a/clientloop.c b/clientloop.c |
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index 87ceb3d..1e05cba 100644 |
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--- a/clientloop.c |
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+++ b/clientloop.c |
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@@ -311,11 +311,10 @@ client_x11_get_proto(const char *display, const char *xauth_path, |
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static char proto[512], data[512]; |
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FILE *f; |
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int got_data = 0, generated = 0, do_unlink = 0, i; |
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- char *xauthdir, *xauthfile; |
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+ char xauthdir[MAXPATHLEN] = "", xauthfile[MAXPATHLEN] = ""; |
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struct stat st; |
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u_int now, x11_timeout_real; |
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- xauthdir = xauthfile = NULL; |
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*_proto = proto; |
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*_data = data; |
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proto[0] = data[0] = '\0'; |
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@@ -343,8 +342,6 @@ client_x11_get_proto(const char *display, const char *xauth_path, |
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display = xdisplay; |
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} |
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if (trusted == 0) { |
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- xauthdir = xmalloc(MAXPATHLEN); |
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- xauthfile = xmalloc(MAXPATHLEN); |
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mktemp_proto(xauthdir, MAXPATHLEN); |
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/* |
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* The authentication cookie should briefly outlive |
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@@ -407,8 +404,6 @@ client_x11_get_proto(const char *display, const char *xauth_path, |
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unlink(xauthfile); |
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rmdir(xauthdir); |
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} |
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- free(xauthdir); |
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- free(xauthfile); |
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/* |
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* If we didn't get authentication data, just make up some |
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-- |
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cgit v0.11.2 |
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From ed4ce82dbfa8a3a3c8ea6fa0db113c71e234416c Mon Sep 17 00:00:00 2001 |
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From: "djm@openbsd.org" <djm@openbsd.org> |
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Date: Wed, 13 Jan 2016 23:04:47 +0000 |
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Subject: upstream commit |
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eliminate fallback from untrusted X11 forwarding to trusted |
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forwarding when the X server disables the SECURITY extension; Reported by |
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Thomas Hoger; ok deraadt@ |
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Upstream-ID: f76195bd2064615a63ef9674a0e4096b0713f938 |
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--- |
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clientloop.c | 114 ++++++++++++++++++++++++++++++++++++----------------------- |
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clientloop.h | 4 +-- |
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mux.c | 22 ++++++------ |
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ssh.c | 23 +++++------- |
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4 files changed, 93 insertions(+), 70 deletions(-) |
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diff --git a/clientloop.c b/clientloop.c |
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index f555451..c0386d5 100644 |
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--- a/clientloop.c |
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+++ b/clientloop.c |
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@@ -288,6 +288,9 @@ client_x11_display_valid(const char *display) |
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{ |
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size_t i, dlen; |
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+ if (display == NULL) |
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+ return 0; |
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+ |
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dlen = strlen(display); |
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for (i = 0; i < dlen; i++) { |
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if (!isalnum((u_char)display[i]) && |
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@@ -301,34 +304,33 @@ client_x11_display_valid(const char *display) |
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#define SSH_X11_PROTO "MIT-MAGIC-COOKIE-1" |
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#define X11_TIMEOUT_SLACK 60 |
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-void |
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+int |
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client_x11_get_proto(const char *display, const char *xauth_path, |
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u_int trusted, u_int timeout, char **_proto, char **_data) |
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{ |
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- char cmd[1024]; |
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- char line[512]; |
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- char xdisplay[512]; |
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+ char cmd[1024], line[512], xdisplay[512]; |
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+ char xauthfile[MAXPATHLEN], xauthdir[MAXPATHLEN]; |
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static char proto[512], data[512]; |
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FILE *f; |
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- int got_data = 0, generated = 0, do_unlink = 0, i; |
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- char xauthdir[MAXPATHLEN] = "", xauthfile[MAXPATHLEN] = ""; |
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+ int got_data = 0, generated = 0, do_unlink = 0, i, r; |
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struct stat st; |
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u_int now, x11_timeout_real; |
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*_proto = proto; |
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*_data = data; |
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- proto[0] = data[0] = '\0'; |
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+ proto[0] = data[0] = xauthfile[0] = xauthdir[0] = '\0'; |
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- if (xauth_path == NULL ||(stat(xauth_path, &st) == -1)) { |
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- debug("No xauth program."); |
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- } else if (!client_x11_display_valid(display)) { |
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- logit("DISPLAY '%s' invalid, falling back to fake xauth data", |
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+ if (!client_x11_display_valid(display)) { |
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+ logit("DISPLAY \"%s\" invalid; disabling X11 forwarding", |
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display); |
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- } else { |
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- if (display == NULL) { |
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- debug("x11_get_proto: DISPLAY not set"); |
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- return; |
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- } |
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+ return -1; |
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+ } |
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+ if (xauth_path != NULL && stat(xauth_path, &st) == -1) { |
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+ debug("No xauth program."); |
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+ xauth_path = NULL; |
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+ } |
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+ |
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+ if (xauth_path != NULL) { |
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/* |
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* Handle FamilyLocal case where $DISPLAY does |
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* not match an authorization entry. For this we |
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@@ -337,43 +339,60 @@ client_x11_get_proto(const char *display, const char *xauth_path, |
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* is not perfect. |
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*/ |
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if (strncmp(display, "localhost:", 10) == 0) { |
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- snprintf(xdisplay, sizeof(xdisplay), "unix:%s", |
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- display + 10); |
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+ if ((r = snprintf(xdisplay, sizeof(xdisplay), "unix:%s", |
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+ display + 10)) < 0 || |
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+ (size_t)r >= sizeof(xdisplay)) { |
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+ error("%s: display name too long", __func__); |
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+ return -1; |
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+ } |
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display = xdisplay; |
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} |
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if (trusted == 0) { |
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- mktemp_proto(xauthdir, MAXPATHLEN); |
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/* |
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+ * Generate an untrusted X11 auth cookie. |
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+ * |
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* The authentication cookie should briefly outlive |
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* ssh's willingness to forward X11 connections to |
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* avoid nasty fail-open behaviour in the X server. |
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*/ |
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+ mktemp_proto(xauthdir, sizeof(xauthdir)); |
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+ if (mkdtemp(xauthdir) == NULL) { |
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+ error("%s: mkdtemp: %s", |
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+ __func__, strerror(errno)); |
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+ return -1; |
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+ } |
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+ do_unlink = 1; |
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+ if ((r = snprintf(xauthfile, sizeof(xauthfile), |
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+ "%s/xauthfile", xauthdir)) < 0 || |
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+ (size_t)r >= sizeof(xauthfile)) { |
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+ error("%s: xauthfile path too long", __func__); |
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+ unlink(xauthfile); |
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+ rmdir(xauthdir); |
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+ return -1; |
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+ } |
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+ |
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if (timeout >= UINT_MAX - X11_TIMEOUT_SLACK) |
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x11_timeout_real = UINT_MAX; |
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else |
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x11_timeout_real = timeout + X11_TIMEOUT_SLACK; |
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- if (mkdtemp(xauthdir) != NULL) { |
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- do_unlink = 1; |
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- snprintf(xauthfile, MAXPATHLEN, "%s/xauthfile", |
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- xauthdir); |
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- snprintf(cmd, sizeof(cmd), |
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- "%s -f %s generate %s " SSH_X11_PROTO |
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- " untrusted timeout %u 2>" _PATH_DEVNULL, |
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- xauth_path, xauthfile, display, |
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- x11_timeout_real); |
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- debug2("x11_get_proto: %s", cmd); |
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- if (x11_refuse_time == 0) { |
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- now = monotime() + 1; |
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- if (UINT_MAX - timeout < now) |
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- x11_refuse_time = UINT_MAX; |
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- else |
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- x11_refuse_time = now + timeout; |
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- channel_set_x11_refuse_time( |
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- x11_refuse_time); |
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- } |
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- if (system(cmd) == 0) |
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- generated = 1; |
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+ if ((r = snprintf(cmd, sizeof(cmd), |
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+ "%s -f %s generate %s " SSH_X11_PROTO |
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+ " untrusted timeout %u 2>" _PATH_DEVNULL, |
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+ xauth_path, xauthfile, display, |
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+ x11_timeout_real)) < 0 || |
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+ (size_t)r >= sizeof(cmd)) |
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+ fatal("%s: cmd too long", __func__); |
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+ debug2("%s: %s", __func__, cmd); |
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+ if (x11_refuse_time == 0) { |
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+ now = monotime() + 1; |
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+ if (UINT_MAX - timeout < now) |
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+ x11_refuse_time = UINT_MAX; |
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+ else |
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+ x11_refuse_time = now + timeout; |
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+ channel_set_x11_refuse_time(x11_refuse_time); |
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} |
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+ if (system(cmd) == 0) |
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+ generated = 1; |
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} |
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/* |
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@@ -395,9 +414,7 @@ client_x11_get_proto(const char *display, const char *xauth_path, |
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got_data = 1; |
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if (f) |
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pclose(f); |
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- } else |
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- error("Warning: untrusted X11 forwarding setup failed: " |
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- "xauth key data not generated"); |
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+ } |
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} |
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if (do_unlink) { |
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@@ -405,6 +422,13 @@ client_x11_get_proto(const char *display, const char *xauth_path, |
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rmdir(xauthdir); |
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} |
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+ /* Don't fall back to fake X11 data for untrusted forwarding */ |
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+ if (!trusted && !got_data) { |
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+ error("Warning: untrusted X11 forwarding setup failed: " |
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+ "xauth key data not generated"); |
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+ return -1; |
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+ } |
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+ |
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/* |
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* If we didn't get authentication data, just make up some |
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* data. The forwarding code will check the validity of the |
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@@ -427,6 +451,8 @@ client_x11_get_proto(const char *display, const char *xauth_path, |
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rnd >>= 8; |
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} |
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} |
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+ |
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+ return 0; |
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} |
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/* |
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diff --git a/clientloop.h b/clientloop.h |
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index 338d451..f4d4c69 100644 |
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--- a/clientloop.h |
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+++ b/clientloop.h |
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@@ -39,7 +39,7 @@ |
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/* Client side main loop for the interactive session. */ |
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int client_loop(int, int, int); |
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-void client_x11_get_proto(const char *, const char *, u_int, u_int, |
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+int client_x11_get_proto(const char *, const char *, u_int, u_int, |
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char **, char **); |
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void client_global_request_reply_fwd(int, u_int32_t, void *); |
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void client_session2_setup(int, int, int, const char *, struct termios *, |
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diff --git a/mux.c b/mux.c |
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index f9c3af6..6bf53eb 100644 |
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--- a/mux.c |
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+++ b/mux.c |
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@@ -1354,16 +1354,18 @@ mux_session_confirm(int id, int success, void *arg) |
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char *proto, *data; |
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/* Get reasonable local authentication information. */ |
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- client_x11_get_proto(display, options.xauth_location, |
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+ if (client_x11_get_proto(display, options.xauth_location, |
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options.forward_x11_trusted, options.forward_x11_timeout, |
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- &proto, &data); |
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- /* Request forwarding with authentication spoofing. */ |
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- debug("Requesting X11 forwarding with authentication " |
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- "spoofing."); |
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- x11_request_forwarding_with_spoofing(id, display, proto, |
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- data, 1); |
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- client_expect_confirm(id, "X11 forwarding", CONFIRM_WARN); |
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- /* XXX exit_on_forward_failure */ |
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+ &proto, &data) == 0) { |
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+ /* Request forwarding with authentication spoofing. */ |
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+ debug("Requesting X11 forwarding with authentication " |
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+ "spoofing."); |
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+ x11_request_forwarding_with_spoofing(id, display, proto, |
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+ data, 1); |
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+ /* XXX exit_on_forward_failure */ |
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+ client_expect_confirm(id, "X11 forwarding", |
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+ CONFIRM_WARN); |
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+ } |
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} |
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if (cctx->want_agent_fwd && options.forward_agent) { |
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diff --git a/ssh.c b/ssh.c |
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index 81704ab..096c5b5 100644 |
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--- a/ssh.c |
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+++ b/ssh.c |
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@@ -1626,6 +1626,7 @@ ssh_session(void) |
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struct winsize ws; |
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char *cp; |
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const char *display; |
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+ char *proto = NULL, *data = NULL; |
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/* Enable compression if requested. */ |
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if (options.compression) { |
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@@ -1696,13 +1697,9 @@ ssh_session(void) |
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} |
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/* Request X11 forwarding if enabled and DISPLAY is set. */ |
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display = getenv("DISPLAY"); |
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- if (options.forward_x11 && display != NULL) { |
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- char *proto, *data; |
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- /* Get reasonable local authentication information. */ |
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- client_x11_get_proto(display, options.xauth_location, |
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- options.forward_x11_trusted, |
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- options.forward_x11_timeout, |
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- &proto, &data); |
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+ if (options.forward_x11 && client_x11_get_proto(display, |
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+ options.xauth_location, options.forward_x11_trusted, |
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+ options.forward_x11_timeout, &proto, &data) == 0) { |
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/* Request forwarding with authentication spoofing. */ |
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debug("Requesting X11 forwarding with authentication " |
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"spoofing."); |
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@@ -1792,6 +1789,7 @@ ssh_session2_setup(int id, int success, void *arg) |
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extern char **environ; |
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const char *display; |
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int interactive = tty_flag; |
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+ char *proto = NULL, *data = NULL; |
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if (!success) |
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return; /* No need for error message, channels code sens one */ |
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@@ -1799,12 +1797,9 @@ ssh_session2_setup(int id, int success, void *arg) |
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return; /* No need for error message, channels code sens one */ |
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display = getenv("DISPLAY"); |
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- if (options.forward_x11 && display != NULL) { |
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- char *proto, *data; |
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- /* Get reasonable local authentication information. */ |
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- client_x11_get_proto(display, options.xauth_location, |
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- options.forward_x11_trusted, |
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- options.forward_x11_timeout, &proto, &data); |
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+ if (options.forward_x11 && client_x11_get_proto(display, |
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+ options.xauth_location, options.forward_x11_trusted, |
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+ options.forward_x11_timeout, &proto, &data) == 0) { |
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/* Request forwarding with authentication spoofing. */ |
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debug("Requesting X11 forwarding with authentication " |
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"spoofing."); |
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-- |
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cgit v0.11.2 |
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From 5658ef2501e785fbbdf5de2dc33b1ff7a4dca73a Mon Sep 17 00:00:00 2001 |
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From: "millert@openbsd.org" <millert@openbsd.org> |
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Date: Mon, 1 Feb 2016 21:18:17 +0000 |
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Subject: upstream commit |
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Avoid ugly "DISPLAY "(null)" invalid; disabling X11 |
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forwarding" message when DISPLAY is not set. This could also result in a |
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crash on systems with a printf that doesn't handle NULL. OK djm@ |
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Upstream-ID: 20ee0cfbda678a247264c20ed75362042b90b412 |
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--- |
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clientloop.c | 7 ++++--- |
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1 file changed, 4 insertions(+), 3 deletions(-) |
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diff --git a/clientloop.c b/clientloop.c |
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index f8f9a3f..f0a08f2 100644 |
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--- a/clientloop.c |
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+++ b/clientloop.c |
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@@ -318,8 +318,9 @@ client_x11_get_proto(const char *display, const char *xauth_path, |
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proto[0] = data[0] = xauthfile[0] = xauthdir[0] = '\0'; |
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if (!client_x11_display_valid(display)) { |
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- logit("DISPLAY \"%s\" invalid; disabling X11 forwarding", |
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- display); |
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+ if (display != NULL) |
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+ logit("DISPLAY \"%s\" invalid; disabling X11 forwarding", |
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+ display); |
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return -1; |
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} |
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if (xauth_path != NULL && stat(xauth_path, &st) == -1) { |
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-- |
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cgit v0.11.2 |
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