diff options
Diffstat (limited to 'ssh.c')
| -rw-r--r-- | ssh.c | 41 |
1 files changed, 40 insertions, 1 deletions
@@ -1,4 +1,4 @@ -/* $OpenBSD: ssh.c,v 1.598 2023/10/12 02:48:43 djm Exp $ */ +/* $OpenBSD: ssh.c,v 1.599 2023/12/18 14:47:44 djm Exp $ */ /* * Author: Tatu Ylonen <ylo@cs.hut.fi> * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland @@ -626,6 +626,41 @@ ssh_conn_info_free(struct ssh_conn_info *cinfo) free(cinfo); } +static int +valid_hostname(const char *s) +{ + size_t i; + + if (*s == '-') + return 0; + for (i = 0; s[i] != 0; i++) { + if (strchr("'`\"$\\;&<>|(){}", s[i]) != NULL || + isspace((u_char)s[i]) || iscntrl((u_char)s[i])) + return 0; + } + return 1; +} + +static int +valid_ruser(const char *s) +{ + size_t i; + + if (*s == '-') + return 0; + for (i = 0; s[i] != 0; i++) { + if (strchr("'`\";&<>|(){}", s[i]) != NULL) + return 0; + /* Disallow '-' after whitespace */ + if (isspace((u_char)s[i]) && s[i + 1] == '-') + return 0; + /* Disallow \ in last position */ + if (s[i] == '\\' && s[i + 1] == '\0') + return 0; + } + return 1; +} + /* * Main program for the ssh client. */ @@ -1118,6 +1153,10 @@ main(int ac, char **av) if (!host) usage(); + if (!valid_hostname(host)) + fatal("hostname contains invalid characters"); + if (options.user != NULL && !valid_ruser(options.user)) + fatal("remote username contains invalid characters"); options.host_arg = xstrdup(host); /* Initialize the command to execute on remote host. */ |