1 files changed, 107 insertions, 12 deletions

diff --git a/readpass.c b/readpass.c
index 7e52cae9c..974d67f0b 100644
--- a/readpass.c
+++ b/readpass.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: readpass.c,v 1.54 2019/06/28 13:35:04 deraadt Exp $ */
+/* $OpenBSD: readpass.c,v 1.61 2020/01/23 07:10:22 dtucker Exp $ */
 /*
  * Copyright (c) 2001 Markus Friedl.  All rights reserved.
  *
@@ -48,7 +48,7 @@
 #include "uidswap.h"
 
 static char *
-ssh_askpass(char *askpass, const char *msg)
+ssh_askpass(char *askpass, const char *msg, const char *env_hint)
 {
         pid_t pid, ret;
         size_t len;
@@ -58,25 +58,27 @@ ssh_askpass(char *askpass, const char *msg)
         void (*osigchld)(int);
 
         if (fflush(stdout) != 0)
-                error("ssh_askpass: fflush: %s", strerror(errno));
+                error("%s: fflush: %s", __func__, strerror(errno));
         if (askpass == NULL)
                 fatal("internal error: askpass undefined");
         if (pipe(p) == -1) {
-                error("ssh_askpass: pipe: %s", strerror(errno));
+                error("%s: pipe: %s", __func__, strerror(errno));
                 return NULL;
         }
-        osigchld = signal(SIGCHLD, SIG_DFL);
+        osigchld = ssh_signal(SIGCHLD, SIG_DFL);
         if ((pid = fork()) == -1) {
-                error("ssh_askpass: fork: %s", strerror(errno));
-                signal(SIGCHLD, osigchld);
+                error("%s: fork: %s", __func__, strerror(errno));
+                ssh_signal(SIGCHLD, osigchld);
                 return NULL;
         }
         if (pid == 0) {
                 close(p[0]);
                 if (dup2(p[1], STDOUT_FILENO) == -1)
-                        fatal("ssh_askpass: dup2: %s", strerror(errno));
+                        fatal("%s: dup2: %s", __func__, strerror(errno));
+                if (env_hint != NULL)
+                        setenv("SSH_ASKPASS_PROMPT", env_hint, 1);
                 execlp(askpass, askpass, msg, (char *)NULL);
-                fatal("ssh_askpass: exec(%s): %s", askpass, strerror(errno));
+                fatal("%s: exec(%s): %s", __func__, askpass, strerror(errno));
         }
         close(p[1]);
 
@@ -96,7 +98,7 @@ ssh_askpass(char *askpass, const char *msg)
         while ((ret = waitpid(pid, &status, 0)) == -1)
                 if (errno != EINTR)
                         break;
-        signal(SIGCHLD, osigchld);
+        ssh_signal(SIGCHLD, osigchld);
         if (ret == -1 || !WIFEXITED(status) || WEXITSTATUS(status) != 0) {
                 explicit_bzero(buf, sizeof(buf));
                 return NULL;
@@ -108,6 +110,9 @@ ssh_askpass(char *askpass, const char *msg)
         return pass;
 }
 
+/* private/internal read_passphrase flags */
+#define RP_ASK_PERMISSION       0x8000 /* pass hint to askpass for confirm UI */
+
 /*
  * Reads a passphrase from /dev/tty with echo turned off/on.  Returns the
  * passphrase (allocated with xmalloc).  Exits if EOF is encountered. If
@@ -119,6 +124,7 @@ read_passphrase(const char *prompt, int flags)
 {
         char cr = '\r', *askpass = NULL, *ret, buf[1024];
         int rppflags, use_askpass = 0, ttyfd;
+        const char *askpass_hint = NULL;
 
         rppflags = (flags & RP_ECHO) ? RPP_ECHO_ON : RPP_ECHO_OFF;
         if (flags & RP_USE_ASKPASS)
@@ -155,7 +161,9 @@ read_passphrase(const char *prompt, int flags)
                         askpass = getenv(SSH_ASKPASS_ENV);
                 else
                         askpass = _PATH_SSH_ASKPASS_DEFAULT;
-                if ((ret = ssh_askpass(askpass, prompt)) == NULL)
+                if ((flags & RP_ASK_PERMISSION) != 0)
+                        askpass_hint = "confirm";
+                if ((ret = ssh_askpass(askpass, prompt, askpass_hint)) == NULL)
                         if (!(flags & RP_ALLOW_EOF))
                                 return xstrdup("");
                 return ret;
@@ -183,7 +191,8 @@ ask_permission(const char *fmt, ...)
         vsnprintf(prompt, sizeof(prompt), fmt, args);
         va_end(args);
 
-        p = read_passphrase(prompt, RP_USE_ASKPASS|RP_ALLOW_EOF);
+        p = read_passphrase(prompt,
+            RP_USE_ASKPASS|RP_ALLOW_EOF|RP_ASK_PERMISSION);
         if (p != NULL) {
                 /*
                  * Accept empty responses and responses consisting
@@ -197,3 +206,89 @@ ask_permission(const char *fmt, ...)
 
         return (allowed);
 }
+
+struct notifier_ctx {
+        pid_t pid;
+        void (*osigchld)(int);
+};
+
+struct notifier_ctx *
+notify_start(int force_askpass, const char *fmt, ...)
+{
+        va_list args;
+        char *prompt = NULL;
+        int devnull;
+        pid_t pid;
+        void (*osigchld)(int);
+        const char *askpass;
+        struct notifier_ctx *ret;
+
+        va_start(args, fmt);
+        xvasprintf(&prompt, fmt, args);
+        va_end(args);
+
+        if (fflush(NULL) != 0)
+                error("%s: fflush: %s", __func__, strerror(errno));
+        if (!force_askpass && isatty(STDERR_FILENO)) {
+                (void)write(STDERR_FILENO, "\r", 1);
+                (void)write(STDERR_FILENO, prompt, strlen(prompt));
+                (void)write(STDERR_FILENO, "\r\n", 2);
+                free(prompt);
+                return NULL;
+        }
+        if ((askpass = getenv("SSH_ASKPASS")) == NULL)
+                askpass = _PATH_SSH_ASKPASS_DEFAULT;
+        if (getenv("DISPLAY") == NULL || *askpass == '\0') {
+                debug3("%s: cannot notify", __func__);
+                free(prompt);
+                return NULL;
+        }
+        osigchld = ssh_signal(SIGCHLD, SIG_DFL);
+        if ((pid = fork()) == -1) {
+                error("%s: fork: %s", __func__, strerror(errno));
+                ssh_signal(SIGCHLD, osigchld);
+                free(prompt);
+                return NULL;
+        }
+        if (pid == 0) {
+                if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1)
+                        fatal("%s: open %s", __func__, strerror(errno));
+                if (dup2(devnull, STDIN_FILENO) == -1 ||
+                    dup2(devnull, STDOUT_FILENO) == -1)
+                        fatal("%s: dup2: %s", __func__, strerror(errno));
+                closefrom(STDERR_FILENO + 1);
+                setenv("SSH_ASKPASS_PROMPT", "none", 1); /* hint to UI */
+                execlp(askpass, askpass, prompt, (char *)NULL);
+                error("%s: exec(%s): %s", __func__, askpass, strerror(errno));
+                _exit(1);
+                /* NOTREACHED */
+        }
+        if ((ret = calloc(1, sizeof(*ret))) == NULL) {
+                kill(pid, SIGTERM);
+                fatal("%s: calloc failed", __func__);
+        }
+        ret->pid = pid;
+        ret->osigchld = osigchld;
+        free(prompt);
+        return ret;
+}
+
+void
+notify_complete(struct notifier_ctx *ctx)
+{
+        int ret;
+
+        if (ctx == NULL || ctx->pid <= 0) {
+                free(ctx);
+                return;
+        }
+        kill(ctx->pid, SIGTERM);
+        while ((ret = waitpid(ctx->pid, NULL, 0)) == -1) {
+                if (errno != EINTR)
+                        break;
+        }
+        if (ret == -1)
+                fatal("%s: waitpid: %s", __func__, strerror(errno));
+        ssh_signal(SIGCHLD, ctx->osigchld);
+        free(ctx);
+}