diff options
| -rw-r--r-- | usr.bin/ssh/ssh-keyscan.c | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/usr.bin/ssh/ssh-keyscan.c b/usr.bin/ssh/ssh-keyscan.c index 1b75bbefc34..225884e2180 100644 --- a/usr.bin/ssh/ssh-keyscan.c +++ b/usr.bin/ssh/ssh-keyscan.c @@ -1,4 +1,4 @@ -/* $OpenBSD: ssh-keyscan.c,v 1.145 2022/01/21 00:53:40 deraadt Exp $ */ +/* $OpenBSD: ssh-keyscan.c,v 1.146 2022/08/19 04:02:46 dtucker Exp $ */ /* * Copyright 1995, 1996 by David Mazieres <dm@lcs.mit.edu>. * @@ -470,6 +470,15 @@ congreet(int s) return; } + /* + * Read the server banner as per RFC4253 section 4.2. The "SSH-" + * protocol identification string may be preceeded by an arbitarily + * large banner which we must read and ignore. Loop while reading + * newline-terminated lines until we have one starting with "SSH-". + * The ID string cannot be longer than 255 characters although the + * preceeding banner lines may (in which case they'll be discarded + * in multiple iterations of the outer loop). + */ for (;;) { memset(buf, '\0', sizeof(buf)); bufsiz = sizeof(buf); @@ -497,6 +506,11 @@ congreet(int s) conrecycle(s); return; } + if (cp >= buf + sizeof(buf)) { + error("%s: greeting exceeds allowable length", c->c_name); + confree(s); + return; + } if (*cp != '\n' && *cp != '\r') { error("%s: bad greeting", c->c_name); confree(s); |