Go back to escaping the command args for "sudo -i" and "sudo -s"

millert · millert · commit 8255ed69b9c4 · 2011-07-29T10:10:40.000-04:00
before calling the plugin.  Otherwise, spaces in the command args
are not treated properly.  The sudoers plugin will unescape non-spaces
to make matching easier.
diff --git a/plugins/sudoers/sudoers.c b/plugins/sudoers/sudoers.c
@@ -861,21 +861,38 @@ set_cmnd(void)
 
 	/* set user_args */
 	if (NewArgc > 1) {
-	    char *to, **from;
+	    char *to, *from, **av;
 	    size_t size, n;
 
 	    /* Alloc and build up user_args. */
-	    for (size = 0, from = NewArgv + 1; *from; from++)
-		size += strlen(*from) + 1;
+	    for (size = 0, av = NewArgv + 1; *av; av++)
+		size += strlen(*av) + 1;
 	    user_args = emalloc(size);
-	    for (to = user_args, from = NewArgv + 1; *from; from++) {
-		n = strlcpy(to, *from, size - (to - user_args));
-		if (n >= size - (to - user_args))
-		    errorx(1, _("internal error, set_cmnd() overflow"));
-		to += n;
-		*to++ = ' ';
+	    if (ISSET(sudo_mode, MODE_SHELL|MODE_LOGIN_SHELL)) {
+		/*
+		 * When running a command via a shell, the sudo front-end
+		 * escapes potential meta chars.  We unescape non-spaces
+		 * for sudoers matching and logging purposes.
+		 */
+		for (to = user_args, av = NewArgv + 1; (from = *av); av++) {
+		    while (*from) {
+			if (from[0] == '\\' && !isspace((unsigned char)from[1]))
+			    from++;
+			*to++ = *from++;
+		    }
+		    *to++ = ' ';
+		}
+		*--to = '\0';
+	    } else {
+		for (to = user_args, av = NewArgv + 1; *av; av++) {
+		    n = strlcpy(to, *av, size - (to - user_args));
+		    if (n >= size - (to - user_args))
+			errorx(1, _("internal error, set_cmnd() overflow"));
+		    to += n;
+		    *to++ = ' ';
+		}
+		*--to = '\0';
 	    }
-	    *--to = '\0';
 	}
     }
     if (strlen(user_cmnd) >= PATH_MAX)
diff --git a/src/parse_args.c b/src/parse_args.c
@@ -385,17 +385,28 @@ parse_args(int argc, char **argv, int *nargc, char ***nargv, char ***settingsp,
 	    memcpy(av + 1, argv, argc * sizeof(char *));
 	} else {
 	    /* shell -c "command" */
-	    char *src, *dst, *end;
+	    char *cmnd, *src, *dst;
 	    size_t cmnd_size = (size_t) (argv[argc - 1] - argv[0]) +
-		    strlen(argv[argc - 1]) + 1;
+		strlen(argv[argc - 1]) + 1;
+
+	    cmnd = dst = emalloc2(cmnd_size, 2);
+	    for (av = argv; *av != NULL; av++) {
+		for (src = *av; *src != '\0'; src++) {
+		    /* quote potential meta characters */
+		    if (!isalnum((unsigned char)*src) && *src != '_' && *src != '-')
+			*dst++ = '\\';
+		    *dst++ = *src;
+		}
+		*dst++ = ' ';
+	    }
+	    if (cmnd != dst)
+		dst--;  /* replace last space with a NUL */
+	    *dst = '\0';
+
 	    ac = 3;
 	    av = emalloc2(ac + 1, sizeof(char *));
 	    av[1] = "-c";
-	    av[2] = dst = emalloc(cmnd_size);
-	    src = argv[0];
-	    for (end = src + cmnd_size - 1; src < end; src++, dst++)
-		*dst = *src == '\0' ? ' ' : *src;
-	    *dst = '\0';
+	    av[2] = cmnd;
 	}
 	av[0] = (char *)user_details.shell; /* plugin may override shell */
 	av[ac] = NULL;
diff --git a/src/sudo.c b/src/sudo.c
@@ -121,7 +121,6 @@ static int iolog_open(struct plugin_container *plugin, char * const settings[],
     int argc, char * const argv[], char * const user_env[]);
 static void iolog_close(struct plugin_container *plugin, int exit_status,
     int error);
-static char *escape_cmnd(const char *src);
 
 /* Policy plugin convenience functions. */
 static int policy_open(struct plugin_container *plugin, char * const settings[],
@@ -293,12 +292,6 @@ main(int argc, char *argv[], char *envp[])
 	    if (ISSET(command_details.flags, CD_SUDOEDIT)) {
 		exitcode = sudo_edit(&command_details);
 	    } else {
-		if (ISSET(sudo_mode, MODE_SHELL)) {
-		    /* Escape meta chars if running a shell with args. */
-		    if (argv_out[1] != NULL && strcmp(argv_out[1], "-c") == 0 &&
-			argv_out[2] != NULL && argv_out[3] == NULL)
-			argv_out[2] = escape_cmnd(argv_out[2]);
-		}
 		exitcode = run_command(&command_details);
 	    }
 	    /* The close method was called by sudo_edit/run_command. */
@@ -1054,30 +1047,6 @@ exec_setup(struct command_details *details, const char *ptyname, int ptyfd)
     return rval;
 }
 
-/*
- * Escape any non-alpha numeric or blank characters to make sure
- * they are not interpreted specially by the shell.
- */
-static char *
-escape_cmnd(const char *src)
-{
-    char *cmnd, *dst;
-
-    /* Worst case scenario, we have to escape everything. */
-    cmnd = dst = emalloc((2 * strlen(src)) + 1);
-    while (*src != '\0') {
-	if (!isalnum((unsigned char)*src) && !isspace((unsigned char)*src) &&
-	    *src != '_' && *src != '-') {
-	    /* quote potential meta character */
-	    *dst++ = '\\';
-	}
-	*dst++ = *src++;
-    }
-    *dst++ = '\0';
-
-    return cmnd;
-}
-
 /*
  * Run the command and wait for it to complete.
  */
