diff --git a/ChangeLog b/ChangeLog index bbc4435df..178d05006 100644 --- a/ChangeLog +++ b/ChangeLog @@ -17,6 +17,11 @@ [ssh-keygen.c] print details of which host lines were deleted when using "ssh-keygen -R host"; ok markus@ + - djm@cvs.openbsd.org 2012/08/17 01:30:00 + [compat.c sshconnect.c] + Send client banner immediately, rather than waiting for the server to + move first for SSH protocol 2 connections (the default). Patch based on + one in bz#1999 by tls AT panix.com, feedback dtucker@ ok markus@ 20120830 - (dtucker) [moduli] Import new moduli file. diff --git a/compat.c b/compat.c index 0dc089fd6..f680f4fe3 100644 --- a/compat.c +++ b/compat.c @@ -1,4 +1,4 @@ -/* $OpenBSD: compat.c,v 1.79 2011/09/23 07:45:05 markus Exp $ */ +/* $OpenBSD: compat.c,v 1.80 2012/08/17 01:30:00 djm Exp $ */ /* * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved. * @@ -45,6 +45,8 @@ int datafellows = 0; void enable_compat20(void) { + if (compat20) + return; debug("Enabling compatibility mode for protocol 2.0"); compat20 = 1; } diff --git a/sshconnect.c b/sshconnect.c index 0ee726637..3d44b2e46 100644 --- a/sshconnect.c +++ b/sshconnect.c @@ -1,4 +1,4 @@ -/* $OpenBSD: sshconnect.c,v 1.234 2011/05/24 07:15:47 djm Exp $ */ +/* $OpenBSD: sshconnect.c,v 1.235 2012/08/17 01:30:00 djm Exp $ */ /* * Author: Tatu Ylonen * Copyright (c) 1995 Tatu Ylonen , Espoo, Finland @@ -429,6 +429,26 @@ ssh_connect(const char *host, struct sockaddr_storage * hostaddr, return 0; } +static void +send_client_banner(int connection_out, int minor1) +{ + char buf[256]; + + /* Send our own protocol version identification. */ + if (compat20) { + xasprintf(&client_version_string, "SSH-%d.%d-%.100s\r\n", + PROTOCOL_MAJOR_2, PROTOCOL_MINOR_2, SSH_VERSION); + } else { + xasprintf(&client_version_string, "SSH-%d.%d-%.100s\n", + PROTOCOL_MAJOR_1, minor1, SSH_VERSION); + } + if (roaming_atomicio(vwrite, connection_out, client_version_string, + strlen(client_version_string)) != strlen(client_version_string)) + fatal("write: %.100s", strerror(errno)); + chop(client_version_string); + debug("Local version string %.100s", client_version_string); +} + /* * Waits for the server identification string, and sends our own * identification string. @@ -440,7 +460,7 @@ ssh_exchange_identification(int timeout_ms) int remote_major, remote_minor, mismatch; int connection_in = packet_get_connection_in(); int connection_out = packet_get_connection_out(); - int minor1 = PROTOCOL_MINOR_1; + int minor1 = PROTOCOL_MINOR_1, client_banner_sent = 0; u_int i, n; size_t len; int fdsetsz, remaining, rc; @@ -450,6 +470,16 @@ ssh_exchange_identification(int timeout_ms) fdsetsz = howmany(connection_in + 1, NFDBITS) * sizeof(fd_mask); fdset = xcalloc(1, fdsetsz); + /* + * If we are SSH2-only then we can send the banner immediately and + * save a round-trip. + */ + if (options.protocol == SSH_PROTO_2) { + enable_compat20(); + send_client_banner(connection_out, 0); + client_banner_sent = 1; + } + /* Read other side's version identification. */ remaining = timeout_ms; for (n = 0;;) { @@ -552,18 +582,9 @@ ssh_exchange_identification(int timeout_ms) fatal("Protocol major versions differ: %d vs. %d", (options.protocol & SSH_PROTO_2) ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1, remote_major); - /* Send our own protocol version identification. */ - snprintf(buf, sizeof buf, "SSH-%d.%d-%.100s%s", - compat20 ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1, - compat20 ? PROTOCOL_MINOR_2 : minor1, - SSH_VERSION, compat20 ? "\r\n" : "\n"); - if (roaming_atomicio(vwrite, connection_out, buf, strlen(buf)) - != strlen(buf)) - fatal("write: %.100s", strerror(errno)); - client_version_string = xstrdup(buf); - chop(client_version_string); + if (!client_banner_sent) + send_client_banner(connection_out, minor1); chop(server_version_string); - debug("Local version string %.100s", client_version_string); } /* defaults to 'no' */