diff options
Diffstat (limited to 'auth2.c')
| -rw-r--r-- | auth2.c | 78 |
1 files changed, 74 insertions, 4 deletions
@@ -1,4 +1,4 @@ -/* $OpenBSD: auth2.c,v 1.116 2007/09/29 00:25:51 dtucker Exp $ */ +/* $OpenBSD: auth2.c,v 1.117 2008/07/02 12:36:39 djm Exp $ */ /* * Copyright (c) 2000 Markus Friedl. All rights reserved. * @@ -26,10 +26,14 @@ #include "includes.h" #include <sys/types.h> +#include <sys/stat.h> +#include <sys/uio.h> +#include <fcntl.h> #include <pwd.h> #include <stdarg.h> #include <string.h> +#include <unistd.h> #include "xmalloc.h" #include "ssh2.h" @@ -88,10 +92,74 @@ static void input_userauth_request(int, u_int32_t, void *); static Authmethod *authmethod_lookup(const char *); static char *authmethods_get(void); +char * +auth2_read_banner(void) +{ + struct stat st; + char *banner = NULL; + size_t len, n; + int fd; + + if ((fd = open(options.banner, O_RDONLY)) == -1) + return (NULL); + if (fstat(fd, &st) == -1) { + close(fd); + return (NULL); + } + if (st.st_size > 1*1024*1024) { + close(fd); + return (NULL); + } + + len = (size_t)st.st_size; /* truncate */ + banner = xmalloc(len + 1); + n = atomicio(read, fd, banner, len); + close(fd); + + if (n != len) { + xfree(banner); + return (NULL); + } + banner[n] = '\0'; + + return (banner); +} + +void +userauth_send_banner(const char *msg) +{ + if (datafellows & SSH_BUG_BANNER) + return; + + packet_start(SSH2_MSG_USERAUTH_BANNER); + packet_put_cstring(msg); + packet_put_cstring(""); /* language, unused */ + packet_send(); + debug("%s: sent", __func__); +} + +static void +userauth_banner(void) +{ + char *banner = NULL; + + if (options.banner == NULL || + strcasecmp(options.banner, "none") == 0 || + (datafellows & SSH_BUG_BANNER) != 0) + return; + + if ((banner = PRIVSEP(auth2_read_banner())) == NULL) + goto done; + userauth_send_banner(banner); + +done: + if (banner) + xfree(banner); +} + /* * loop until authctxt->success == TRUE */ - void do_authentication2(Authctxt *authctxt) { @@ -179,6 +247,7 @@ input_userauth_request(int type, u_int32_t seq, void *ctxt) authctxt->style = style ? xstrdup(style) : NULL; if (use_privsep) mm_inform_authserv(service, style); + userauth_banner(); } else if (strcmp(user, authctxt->user) != 0 || strcmp(service, authctxt->service) != 0) { packet_disconnect("Change of username or service not allowed: " @@ -197,7 +266,7 @@ input_userauth_request(int type, u_int32_t seq, void *ctxt) /* try to authenticate user */ m = authmethod_lookup(method); - if (m != NULL) { + if (m != NULL && authctxt->failures < options.max_authtries) { debug2("input_userauth_request: try method %s", method); authenticated = m->userauth(authctxt); } @@ -264,7 +333,7 @@ userauth_finish(Authctxt *authctxt, int authenticated, char *method) /* now we can break out */ authctxt->success = 1; } else { - if (authctxt->failures++ > options.max_authtries) { + if (++authctxt->failures > options.max_authtries) { #ifdef SSH_AUDIT_EVENTS PRIVSEP(audit_event(SSH_LOGIN_EXCEED_MAXTRIES)); #endif @@ -320,3 +389,4 @@ authmethod_lookup(const char *name) name ? name : "NULL"); return NULL; } + |