[auth.h auth2-chall.c auth2.c monitor.c sshd_config.5]
     add submethod support to AuthenticationMethods; ok and freedback djm@
This commit is contained in:
Damien Miller 2013-04-23 15:18:10 +10:00
parent 4ce189d910
commit 91a55f28f3
6 changed files with 91 additions and 34 deletions

View File

@ -19,6 +19,9 @@
have included a style (e.g. "root:skey") when checking public key
signatures. Fixes public key and hostbased auth when the client specified
a style; ok markus@
- markus@cvs.openbsd.org 2013/03/07 19:27:25
[auth.h auth2-chall.c auth2.c monitor.c sshd_config.5]
add submethod support to AuthenticationMethods; ok and freedback djm@
20130418
- (djm) [config.guess config.sub] Update to last versions before they switch

5
auth.h
View File

@ -1,4 +1,4 @@
/* $OpenBSD: auth.h,v 1.72 2012/12/02 20:34:09 djm Exp $ */
/* $OpenBSD: auth.h,v 1.73 2013/03/07 19:27:25 markus Exp $ */
/*
* Copyright (c) 2000 Markus Friedl. All rights reserved.
@ -157,8 +157,9 @@ void userauth_send_banner(const char *);
char *auth2_read_banner(void);
int auth2_methods_valid(const char *, int);
int auth2_update_methods_lists(Authctxt *, const char *);
int auth2_update_methods_lists(Authctxt *, const char *, const char *);
int auth2_setup_methods_lists(Authctxt *);
int auth2_method_allowed(Authctxt *, const char *, const char *);
void privsep_challenge_enable(void);

View File

@ -1,4 +1,4 @@
/* $OpenBSD: auth2-chall.c,v 1.36 2012/12/03 00:14:06 djm Exp $ */
/* $OpenBSD: auth2-chall.c,v 1.37 2013/03/07 19:27:25 markus Exp $ */
/*
* Copyright (c) 2001 Markus Friedl. All rights reserved.
* Copyright (c) 2001 Per Allansson. All rights reserved.
@ -155,7 +155,7 @@ kbdint_free(KbdintAuthctxt *kbdintctxt)
}
/* get next device */
static int
kbdint_next_device(KbdintAuthctxt *kbdintctxt)
kbdint_next_device(Authctxt *authctxt, KbdintAuthctxt *kbdintctxt)
{
size_t len;
char *t;
@ -169,9 +169,13 @@ kbdint_next_device(KbdintAuthctxt *kbdintctxt)
if (len == 0)
break;
for (i = 0; devices[i]; i++)
for (i = 0; devices[i]; i++) {
if (!auth2_method_allowed(authctxt,
"keyboard-interactive", devices[i]->name))
continue;
if (strncmp(kbdintctxt->devices, devices[i]->name, len) == 0)
kbdintctxt->device = devices[i];
}
t = kbdintctxt->devices;
kbdintctxt->devices = t[len] ? xstrdup(t+len+1) : NULL;
xfree(t);
@ -221,7 +225,7 @@ auth2_challenge_start(Authctxt *authctxt)
debug2("auth2_challenge_start: devices %s",
kbdintctxt->devices ? kbdintctxt->devices : "<empty>");
if (kbdint_next_device(kbdintctxt) == 0) {
if (kbdint_next_device(authctxt, kbdintctxt) == 0) {
auth2_challenge_stop(authctxt);
return 0;
}

76
auth2.c
View File

@ -1,4 +1,4 @@
/* $OpenBSD: auth2.c,v 1.126 2012/12/02 20:34:09 djm Exp $ */
/* $OpenBSD: auth2.c,v 1.127 2013/03/07 19:27:25 markus Exp $ */
/*
* Copyright (c) 2000 Markus Friedl. All rights reserved.
*
@ -98,8 +98,12 @@ static void input_userauth_request(int, u_int32_t, void *);
/* helper */
static Authmethod *authmethod_lookup(Authctxt *, const char *);
static char *authmethods_get(Authctxt *authctxt);
static int method_allowed(Authctxt *, const char *);
static int list_starts_with(const char *, const char *);
#define MATCH_NONE 0 /* method or submethod mismatch */
#define MATCH_METHOD 1 /* method matches (no submethod specified) */
#define MATCH_BOTH 2 /* method and submethod match */
#define MATCH_PARTIAL 3 /* method matches, submethod can't be checked */
static int list_starts_with(const char *, const char *, const char *);
char *
auth2_read_banner(void)
@ -316,7 +320,7 @@ userauth_finish(Authctxt *authctxt, int authenticated, const char *method,
}
if (authenticated && options.num_auth_methods != 0) {
if (!auth2_update_methods_lists(authctxt, method)) {
if (!auth2_update_methods_lists(authctxt, method, submethod)) {
authenticated = 0;
partial = 1;
}
@ -387,8 +391,9 @@ userauth_finish(Authctxt *authctxt, int authenticated, const char *method,
* methods list. Returns 1 if allowed, or no methods lists configured.
* 0 otherwise.
*/
static int
method_allowed(Authctxt *authctxt, const char *method)
int
auth2_method_allowed(Authctxt *authctxt, const char *method,
const char *submethod)
{
u_int i;
@ -399,7 +404,8 @@ method_allowed(Authctxt *authctxt, const char *method)
if (options.num_auth_methods == 0)
return 1;
for (i = 0; i < authctxt->num_auth_methods; i++) {
if (list_starts_with(authctxt->auth_methods[i], method))
if (list_starts_with(authctxt->auth_methods[i], method,
submethod) != MATCH_NONE)
return 1;
}
return 0;
@ -419,7 +425,8 @@ authmethods_get(Authctxt *authctxt)
if (authmethods[i]->enabled == NULL ||
*(authmethods[i]->enabled) == 0)
continue;
if (!method_allowed(authctxt, authmethods[i]->name))
if (!auth2_method_allowed(authctxt, authmethods[i]->name,
NULL))
continue;
if (buffer_len(&b) > 0)
buffer_append(&b, ",", 1);
@ -442,7 +449,8 @@ authmethod_lookup(Authctxt *authctxt, const char *name)
if (authmethods[i]->enabled != NULL &&
*(authmethods[i]->enabled) != 0 &&
strcmp(name, authmethods[i]->name) == 0 &&
method_allowed(authctxt, authmethods[i]->name))
auth2_method_allowed(authctxt,
authmethods[i]->name, NULL))
return authmethods[i];
debug2("Unrecognized authentication method name: %s",
name ? name : "NULL");
@ -457,7 +465,7 @@ authmethod_lookup(Authctxt *authctxt, const char *name)
int
auth2_methods_valid(const char *_methods, int need_enable)
{
char *methods, *omethods, *method;
char *methods, *omethods, *method, *p;
u_int i, found;
int ret = -1;
@ -468,6 +476,8 @@ auth2_methods_valid(const char *_methods, int need_enable)
omethods = methods = xstrdup(_methods);
while ((method = strsep(&methods, ",")) != NULL) {
for (found = i = 0; !found && authmethods[i] != NULL; i++) {
if ((p = strchr(method, ':')) != NULL)
*p = '\0';
if (strcmp(method, authmethods[i]->name) != 0)
continue;
if (need_enable) {
@ -533,15 +543,30 @@ auth2_setup_methods_lists(Authctxt *authctxt)
}
static int
list_starts_with(const char *methods, const char *method)
list_starts_with(const char *methods, const char *method,
const char *submethod)
{
size_t l = strlen(method);
int match;
const char *p;
if (strncmp(methods, method, l) != 0)
return 0;
if (methods[l] != ',' && methods[l] != '\0')
return 0;
return 1;
return MATCH_NONE;
p = methods + l;
match = MATCH_METHOD;
if (*p == ':') {
if (!submethod)
return MATCH_PARTIAL;
l = strlen(submethod);
p += 1;
if (strncmp(submethod, p, l))
return MATCH_NONE;
p += l;
match = MATCH_BOTH;
}
if (*p != ',' && *p != '\0')
return MATCH_NONE;
return match;
}
/*
@ -550,14 +575,21 @@ list_starts_with(const char *methods, const char *method)
* if it did.
*/
static int
remove_method(char **methods, const char *method)
remove_method(char **methods, const char *method, const char *submethod)
{
char *omethods = *methods;
char *omethods = *methods, *p;
size_t l = strlen(method);
int match;
if (!list_starts_with(omethods, method))
match = list_starts_with(omethods, method, submethod);
if (match != MATCH_METHOD && match != MATCH_BOTH)
return 0;
*methods = xstrdup(omethods + l + (omethods[l] == ',' ? 1 : 0));
p = omethods + l;
if (submethod && match == MATCH_BOTH)
p += 1 + strlen(submethod); /* include colon */
if (*p == ',')
p++;
*methods = xstrdup(p);
free(omethods);
return 1;
}
@ -569,13 +601,15 @@ remove_method(char **methods, const char *method)
* Returns 1 if the method completed any authentication list or 0 otherwise.
*/
int
auth2_update_methods_lists(Authctxt *authctxt, const char *method)
auth2_update_methods_lists(Authctxt *authctxt, const char *method,
const char *submethod)
{
u_int i, found = 0;
debug3("%s: updating methods list after \"%s\"", __func__, method);
for (i = 0; i < authctxt->num_auth_methods; i++) {
if (!remove_method(&(authctxt->auth_methods[i]), method))
if (!remove_method(&(authctxt->auth_methods[i]), method,
submethod))
continue;
found = 1;
if (*authctxt->auth_methods[i] == '\0') {

View File

@ -1,4 +1,4 @@
/* $OpenBSD: monitor.c,v 1.121 2013/03/07 00:19:59 djm Exp $ */
/* $OpenBSD: monitor.c,v 1.122 2013/03/07 19:27:25 markus Exp $ */
/*
* Copyright 2002 Niels Provos <provos@citi.umich.edu>
* Copyright 2002 Markus Friedl <markus@openbsd.org>
@ -392,7 +392,7 @@ monitor_child_preauth(Authctxt *_authctxt, struct monitor *pmonitor)
"with SSH protocol 1");
if (authenticated &&
!auth2_update_methods_lists(authctxt,
auth_method)) {
auth_method, auth_submethod)) {
debug3("%s: method %s: partial", __func__,
auth_method);
authenticated = 0;
@ -949,9 +949,10 @@ mm_answer_bsdauthrespond(int sock, Buffer *m)
debug3("%s: sending authenticated: %d", __func__, authok);
mm_request_send(sock, MONITOR_ANS_BSDAUTHRESPOND, m);
if (compat20)
auth_method = "keyboard-interactive"; /* XXX auth_submethod */
else
if (compat20) {
auth_method = "keyboard-interactive";
auth_submethod = "bsdauth";
} else
auth_method = "bsdauth";
return (authok != 0);

View File

@ -33,8 +33,8 @@
.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
.\"
.\" $OpenBSD: sshd_config.5,v 1.156 2013/02/06 00:20:42 dtucker Exp $
.Dd $Mdocdate: February 6 2013 $
.\" $OpenBSD: sshd_config.5,v 1.157 2013/03/07 19:27:25 markus Exp $
.Dd $Mdocdate: March 7 2013 $
.Dt SSHD_CONFIG 5
.Os
.Sh NAME
@ -180,6 +180,20 @@ Only methods that are next in one or more lists are offered at each stage,
so for this example, it would not be possible to attempt password or
keyboard-interactive authentication before public key.
.Pp
For keyboard interactive authentication it is also possible to
restrict authentication to a specific device by appending a
colon followed by the device identifier
.Dq bsdauth ,
.Dq pam ,
or
.Dq skey ,
depending on the server configuration.
For example,
.Dq keyboard-interactive:bsdauth
would restrict keyboard interactive authentication to the
.Dq bsdauth
device.
.Pp
This option is only available for SSH protocol 2 and will yield a fatal
error if enabled if protocol 1 is also enabled.
Note that each authentication method listed should also be explicitly enabled