diff options
| author | Darren Tucker <dtucker@cvs.openbsd.org> | 2017-11-28 21:10:23 +0000 |
|---|---|---|
| committer | Darren Tucker <dtucker@cvs.openbsd.org> | 2017-11-28 21:10:23 +0000 |
| commit | 1d3a52c99d52ce45a54223243ee2d65360baf947 (patch) | |
| tree | 1f73b989877078c3611b6a0c4f14a3653ea6b571 /usr.bin/ssh | |
| parent | 8feeff644c371b32315861a26a86851734ca0320 (diff) | |
Have sftp print a warning about shell cleanliness when decoding the first
packet fails, which is usually caused by shells polluting stdout of
non-interactive starups. bz#2800, ok markus@ deraadt@.
Diffstat (limited to 'usr.bin/ssh')
| -rw-r--r-- | usr.bin/ssh/sftp-client.c | 20 |
1 files changed, 15 insertions, 5 deletions
diff --git a/usr.bin/ssh/sftp-client.c b/usr.bin/ssh/sftp-client.c index 5db6b5d953a..2f3e68eb196 100644 --- a/usr.bin/ssh/sftp-client.c +++ b/usr.bin/ssh/sftp-client.c @@ -1,4 +1,4 @@ -/* $OpenBSD: sftp-client.c,v 1.127 2017/08/11 04:41:08 djm Exp $ */ +/* $OpenBSD: sftp-client.c,v 1.128 2017/11/28 21:10:22 dtucker Exp $ */ /* * Copyright (c) 2001-2004 Damien Miller <djm@openbsd.org> * @@ -116,7 +116,7 @@ send_msg(struct sftp_conn *conn, struct sshbuf *m) } static void -get_msg(struct sftp_conn *conn, struct sshbuf *m) +get_msg_extended(struct sftp_conn *conn, struct sshbuf *m, int initial) { u_int msg_len; u_char *p; @@ -134,8 +134,12 @@ get_msg(struct sftp_conn *conn, struct sshbuf *m) if ((r = sshbuf_get_u32(m, &msg_len)) != 0) fatal("%s: buffer error: %s", __func__, ssh_err(r)); - if (msg_len > SFTP_MAX_MSG_LENGTH) - fatal("Received message too long %u", msg_len); + if (msg_len > SFTP_MAX_MSG_LENGTH) { + do_log2(initial ? SYSLOG_LEVEL_ERROR : SYSLOG_LEVEL_FATAL, + "Received message too long %u", msg_len); + fatal("Ensure the remote shell produces no output " + "for non-interactive sessions."); + } if ((r = sshbuf_reserve(m, msg_len, &p)) != 0) fatal("%s: buffer error: %s", __func__, ssh_err(r)); @@ -150,6 +154,12 @@ get_msg(struct sftp_conn *conn, struct sshbuf *m) } static void +get_msg(struct sftp_conn *conn, struct sshbuf *m) +{ + get_msg_extended(conn, m, 0); +} + +static void send_string_request(struct sftp_conn *conn, u_int id, u_int code, const char *s, u_int len) { @@ -392,7 +402,7 @@ do_init(int fd_in, int fd_out, u_int transfer_buflen, u_int num_requests, sshbuf_reset(msg); - get_msg(ret, msg); + get_msg_extended(ret, msg, 1); /* Expecting a VERSION reply */ if ((r = sshbuf_get_u8(msg, &type)) != 0) |