ssh-add with stdin and read_passphrase

[Jean-Yves FAYE]

I would like to use ssh-add to unlock a key with a password provided
through a web interface.

It seems even though ssh-add calls read_passphrase with RP_ALLOW_STDIN
at ssh-add.c:173, stdin is not used as a last resort without a valid
terminal or display. Is it an intended behaviour ? And if so, what are
the security implications of using popen() to write the password to
ssh-add (not using echo password|ssh-add of course).


I used this patch solves the issue :

diff -Nru openssh-5.6p1/readpass.c openssh-5.6p1-b/readpass.c
--- openssh-5.6p1/readpass.c	2006-08-05 04:39:40.000000000 +0200
+++ openssh-5.6p1-b/readpass.c	2011-01-18 09:52:34.000000000 +0100
@@ -123,6 +123,7 @@
 		if (!isatty(STDIN_FILENO)) {
 			debug("read_passphrase: stdin is not a tty");
 			use_askpass = 1;
+			rppflags |= RPP_STDIN;
 		}
 	} else {
 		rppflags |= RPP_REQUIRE_TTY;


Thanks
Jean-Yves Faye