Attachment 3347 Details for Bug 69 – enable always: prefix in SSH_ASKPASS, updated patch for OpenSSH 8.0

[patch] enable always: prefix in SSH_ASKPASS, updated patch for OpenSSH 8.0

enable-always-in-ssh-askpass.patch (text/plain), 3.80 KB, created by main.haarp on 2020-01-08 19:13:24 AEDT

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Creator: main.haarp

Created: 2020-01-08 19:13:24 AEDT

Size: 3.80 KB

patch

obsolete

>https://bugzilla.mindrot.org/show_bug.cgi?id=69
>
>--- a/readpass.c	2019-04-18 00:52:57.000000000 +0200
>+++ b/readpass.c	2020-01-08 08:56:36.914975016 +0100
>@@ -117,59 +117,90 @@
> char *
> read_passphrase(const char *prompt, int flags)
> {
>+	static const int askpass_never = 0, askpass_always = 1, askpass_auto = 2;
>+	static const char *prefix_never = "never:", *prefix_always = "always:",
>+		*prefix_auto = "auto:";
>+
> 	char cr = '\r', *askpass = NULL, *ret, buf[1024];
>-	int rppflags, use_askpass = 0, ttyfd;
>+	int rppflags, use_askpass, force_askpass, ttyfd;
>+
>+	/* decode $SSH_ASKPASS */
>+	askpass = getenv(SSH_ASKPASS_ENV);
>+
>+	if(askpass == NULL) {
>+		force_askpass = askpass_auto;
>+		askpass = "";
>+	} else if(strncmp(askpass, prefix_never, strlen(prefix_never)) == 0) {
>+		force_askpass = askpass_never;
>+		askpass += strlen(prefix_never);
>+	} else if(strncmp(askpass, prefix_always, strlen(prefix_always)) == 0) {
>+		force_askpass = askpass_always;
>+		askpass += strlen(prefix_always);
>+	} else if(strncmp(askpass, prefix_auto, strlen(prefix_auto)) == 0) {
>+		force_askpass = askpass_auto;
>+		askpass += strlen(prefix_auto);
>+	} else
>+		force_askpass = askpass_auto;
>+
>+	if(askpass[0] == '\0')
>+		askpass = _PATH_SSH_ASKPASS_DEFAULT;
> 
>-	rppflags = (flags & RP_ECHO) ? RPP_ECHO_ON : RPP_ECHO_OFF;
>-	if (flags & RP_USE_ASKPASS)
>+	if (force_askpass == askpass_always)
> 		use_askpass = 1;
>-	else if (flags & RP_ALLOW_STDIN) {
>-		if (!isatty(STDIN_FILENO)) {
>-			debug("read_passphrase: stdin is not a tty");
>+	else {
>+		/* This block has two purposes:
>+			1.) automatic detection of askpass usesage.  The result will be stored
>+			    in use_askpass and may be overridden by force_askpass == never
>+			2.) determine options and print debug warnings for use with the
>+			    tty/stdin pasphrase reader.
>+		*/
>+		use_askpass = 0;
>+
>+		rppflags = (flags & RP_ECHO) ? RPP_ECHO_ON : RPP_ECHO_OFF;
>+		if (flags & RP_USE_ASKPASS)
> 			use_askpass = 1;
>-		}
>-	} else {
>-		rppflags |= RPP_REQUIRE_TTY;
>-		ttyfd = open(_PATH_TTY, O_RDWR);
>-		if (ttyfd >= 0) {
>-			/*
>-			 * If we're on a tty, ensure that show the prompt at
>-			 * the beginning of the line. This will hopefully
>-			 * clobber any password characters the user has
>-			 * optimistically typed before echo is disabled.
>-			 */
>-			(void)write(ttyfd, &cr, 1);
>-			close(ttyfd);
>+		else if (flags & RP_ALLOW_STDIN) {
>+			if (!isatty(STDIN_FILENO)) {
>+				debug("read_passphrase: stdin is not a tty");
>+				use_askpass = 1;
>+			}
> 		} else {
>-			debug("read_passphrase: can't open %s: %s", _PATH_TTY,
>-			    strerror(errno));
>-			use_askpass = 1;
>+			rppflags |= RPP_REQUIRE_TTY;
>+			ttyfd = open(_PATH_TTY, O_RDWR);
>+			if (ttyfd >= 0)
>+				close(ttyfd);
>+			else {
>+				debug("read_passphrase: can't open %s: %s", _PATH_TTY,
>+					strerror(errno));
>+				use_askpass = 1;
>+			}
> 		}
>+
>+		if(getenv("DISPLAY") == NULL)
>+			use_askpass = 0;
>+
>+		if(force_askpass == askpass_never)
>+			use_askpass = 0;
> 	}
> 
>-	if ((flags & RP_USE_ASKPASS) && getenv("DISPLAY") == NULL)
>+	if (!use_askpass && (flags & RP_USE_ASKPASS))
> 		return (flags & RP_ALLOW_EOF) ? NULL : xstrdup("");
> 
>-	if (use_askpass && getenv("DISPLAY")) {
>-		if (getenv(SSH_ASKPASS_ENV))
>-			askpass = getenv(SSH_ASKPASS_ENV);
>-		else
>-			askpass = _PATH_SSH_ASKPASS_DEFAULT;
>+	if (use_askpass) {
> 		if ((ret = ssh_askpass(askpass, prompt)) == NULL)
> 			if (!(flags & RP_ALLOW_EOF))
> 				return xstrdup("");
> 		return ret;
>+	} else {
>+		if (readpassphrase(prompt, buf, sizeof buf, rppflags) == NULL) {
>+			if (flags & RP_ALLOW_EOF)
>+				return NULL;
>+			return xstrdup("");
>+		}
>+		ret = xstrdup(buf);
>+		memset(buf, 'x', sizeof buf);
>+		return ret;
> 	}
>-
>-	if (readpassphrase(prompt, buf, sizeof buf, rppflags) == NULL) {
>-		if (flags & RP_ALLOW_EOF)
>-			return NULL;
>-		return xstrdup("");
>-	}
>-
>-	ret = xstrdup(buf);
>-	explicit_bzero(buf, sizeof(buf));
>-	return ret;
> }
> 
> int

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