*/
#include "includes.h"
-RCSID("$OpenBSD: auth2.c,v 1.92 2002/05/25 18:51:07 markus Exp $");
+RCSID("$OpenBSD: auth2.c,v 1.104 2003/11/04 08:54:09 djm Exp $");
#include "ssh2.h"
#include "xmalloc.h"
#include "pathnames.h"
#include "monitor_wrap.h"
+#ifdef GSSAPI
+#include "ssh-gss.h"
+#endif
+
/* import */
extern ServerOptions options;
extern u_char *session_id2;
-extern int session_id2_len;
+extern u_int session_id2_len;
-Authctxt *x_authctxt = NULL;
-static int one = 1;
+/* methods */
+
+extern Authmethod method_none;
+extern Authmethod method_pubkey;
+extern Authmethod method_passwd;
+extern Authmethod method_kbdint;
+extern Authmethod method_hostbased;
+#ifdef GSSAPI
+extern Authmethod method_gssapi;
+#endif
-typedef struct Authmethod Authmethod;
-struct Authmethod {
- char *name;
- int (*userauth)(Authctxt *authctxt);
- int *enabled;
+Authmethod *authmethods[] = {
+ &method_none,
+ &method_pubkey,
+#ifdef GSSAPI
+ &method_gssapi,
+#endif
+ &method_passwd,
+ &method_kbdint,
+ &method_hostbased,
+ NULL
};
/* protocol */
static Authmethod *authmethod_lookup(const char *);
static char *authmethods_get(void);
int user_key_allowed(struct passwd *, Key *);
-int hostbased_key_allowed(struct passwd *, const char *, char *, Key *);
-
-/* auth */
-
-Authmethod authmethods[] = {
- {"none",
- userauth_none,
- &one},
- {"publickey",
- userauth_pubkey,
- &options.pubkey_authentication},
- {"password",
- userauth_passwd,
- &options.password_authentication},
- {"keyboard-interactive",
- userauth_kbdint,
- &options.kbd_interactive_authentication},
- {"hostbased",
- userauth_hostbased,
- &options.hostbased_authentication},
- {NULL, NULL, NULL}
-};
/*
* loop until authctxt->success == TRUE
*/
-Authctxt *
-do_authentication2(void)
+void
+do_authentication2(Authctxt *authctxt)
{
- Authctxt *authctxt = authctxt_new();
-
- x_authctxt = authctxt; /*XXX*/
-
/* challenge-response is implemented via keyboard interactive */
if (options.challenge_response_authentication)
options.kbd_interactive_authentication = 1;
- if (options.pam_authentication_via_kbd_int)
- options.kbd_interactive_authentication = 1;
- if (use_privsep)
- options.pam_authentication_via_kbd_int = 0;
dispatch_init(&dispatch_protocol_error);
dispatch_set(SSH2_MSG_SERVICE_REQUEST, &input_service_request);
dispatch_run(DISPATCH_BLOCK, &authctxt->success, authctxt);
-
- return (authctxt);
}
static void
{
Authctxt *authctxt = ctxt;
u_int len;
- int accept = 0;
+ int acceptit = 0;
char *service = packet_get_string(&len);
packet_check_eom();
if (strcmp(service, "ssh-userauth") == 0) {
if (!authctxt->success) {
- accept = 1;
+ acceptit = 1;
/* now we can handle user-auth requests */
dispatch_set(SSH2_MSG_USERAUTH_REQUEST, &input_userauth_request);
}
}
/* XXX all other service requests are denied */
- if (accept) {
+ if (acceptit) {
packet_start(SSH2_MSG_SERVICE_ACCEPT);
packet_put_cstring(service);
packet_send();
if (authctxt->attempt++ == 0) {
/* setup auth context */
authctxt->pw = PRIVSEP(getpwnamallow(user));
+ authctxt->user = xstrdup(user);
if (authctxt->pw && strcmp(service, "ssh-connection")==0) {
authctxt->valid = 1;
debug2("input_userauth_request: setting up authctxt for %s", user);
#ifdef USE_PAM
- PRIVSEP(start_pam(authctxt->pw->pw_name));
+ if (options.use_pam)
+ PRIVSEP(start_pam(authctxt));
#endif
} else {
- log("input_userauth_request: illegal user %s", user);
+ logit("input_userauth_request: illegal user %s", user);
+ authctxt->pw = fakepw();
#ifdef USE_PAM
- PRIVSEP(start_pam("NOUSER"));
+ if (options.use_pam)
+ PRIVSEP(start_pam(authctxt));
#endif
}
setproctitle("%s%s", authctxt->pw ? user : "unknown",
use_privsep ? " [net]" : "");
- authctxt->user = xstrdup(user);
authctxt->service = xstrdup(service);
authctxt->style = style ? xstrdup(style) : NULL;
if (use_privsep)
}
/* reset state */
auth2_challenge_stop(authctxt);
+
+#ifdef GSSAPI
+ dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
+ dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, NULL);
+#endif
+
authctxt->postponed = 0;
/* try to authenticate user */
authenticated = 0;
#ifdef USE_PAM
- if (!use_privsep && authenticated && authctxt->user &&
- !do_pam_account(authctxt->user, NULL))
+ if (options.use_pam && authenticated && !PRIVSEP(do_pam_account()))
authenticated = 0;
-#endif /* USE_PAM */
+#endif
+
+#ifdef _UNICOS
+ if (authenticated && cray_access_denied(authctxt->user)) {
+ authenticated = 0;
+ fatal("Access denied for user %s.",authctxt->user);
+ }
+#endif /* _UNICOS */
/* Log before sending the reply */
auth_log(authctxt, authenticated, method, " ssh2");
/* now we can break out */
authctxt->success = 1;
} else {
- if (authctxt->failures++ > AUTH_FAIL_MAX) {
-#ifdef WITH_AIXAUTHENTICATE
- loginfailed(authctxt->user,
- get_canonical_hostname(options.verify_reverse_mapping),
- "ssh");
-#endif /* WITH_AIXAUTHENTICATE */
+ if (authctxt->failures++ > AUTH_FAIL_MAX)
packet_disconnect(AUTH_FAIL_MSG, authctxt->user);
- }
methods = authmethods_get();
packet_start(SSH2_MSG_USERAUTH_FAILURE);
packet_put_cstring(methods);
}
}
-char *
-auth2_read_banner(void)
-{
- struct stat st;
- char *banner = NULL;
- off_t len, n;
- int fd;
-
- if ((fd = open(options.banner, O_RDONLY)) == -1)
- return (NULL);
- if (fstat(fd, &st) == -1) {
- close(fd);
- return (NULL);
- }
- len = st.st_size;
- banner = xmalloc(len + 1);
- n = atomicio(read, fd, banner, len);
- close(fd);
-
- if (n != len) {
- free(banner);
- return (NULL);
- }
- banner[n] = '\0';
-
- return (banner);
-}
-
-static void
-userauth_banner(void)
-{
- char *banner = NULL;
-
- if (options.banner == NULL || (datafellows & SSH_BUG_BANNER))
- return;
-
- if ((banner = PRIVSEP(auth2_read_banner())) == NULL)
- goto done;
-
- packet_start(SSH2_MSG_USERAUTH_BANNER);
- packet_put_cstring(banner);
- packet_put_cstring(""); /* language, unused */
- packet_send();
- debug("userauth_banner: sent");
-done:
- if (banner)
- xfree(banner);
- return;
-}
-
-static int
-userauth_none(Authctxt *authctxt)
-{
- /* disable method "none", only allowed one time */
- Authmethod *m = authmethod_lookup("none");
- if (m != NULL)
- m->enabled = NULL;
- packet_check_eom();
- userauth_banner();
-
- if (authctxt->valid == 0)
- return(0);
-
-#ifdef HAVE_CYGWIN
- if (check_nt_auth(1, authctxt->pw) == 0)
- return(0);
-#endif
- return PRIVSEP(auth_password(authctxt, ""));
-}
-
-static int
-userauth_passwd(Authctxt *authctxt)
-{
- char *password;
- int authenticated = 0;
- int change;
- u_int len;
- change = packet_get_char();
- if (change)
- log("password change not supported");
- password = packet_get_string(&len);
- packet_check_eom();
- if (authctxt->valid &&
-#ifdef HAVE_CYGWIN
- check_nt_auth(1, authctxt->pw) &&
-#endif
- PRIVSEP(auth_password(authctxt, password)) == 1)
- authenticated = 1;
- memset(password, 0, len);
- xfree(password);
- return authenticated;
-}
-
-static int
-userauth_kbdint(Authctxt *authctxt)
-{
- int authenticated = 0;
- char *lang, *devs;
-
- lang = packet_get_string(NULL);
- devs = packet_get_string(NULL);
- packet_check_eom();
-
- debug("keyboard-interactive devs %s", devs);
-
- if (options.challenge_response_authentication)
- authenticated = auth2_challenge(authctxt, devs);
-
-#ifdef USE_PAM
- if (authenticated == 0 && options.pam_authentication_via_kbd_int)
- authenticated = auth2_pam(authctxt);
-#endif
- xfree(devs);
- xfree(lang);
-#ifdef HAVE_CYGWIN
- if (check_nt_auth(0, authctxt->pw) == 0)
- return(0);
-#endif
- return authenticated;
-}
-
-static int
-userauth_pubkey(Authctxt *authctxt)
-{
- Buffer b;
- Key *key = NULL;
- char *pkalg;
- u_char *pkblob, *sig;
- u_int alen, blen, slen;
- int have_sig, pktype;
- int authenticated = 0;
-
- if (!authctxt->valid) {
- debug2("userauth_pubkey: disabled because of invalid user");
- return 0;
- }
- have_sig = packet_get_char();
- if (datafellows & SSH_BUG_PKAUTH) {
- debug2("userauth_pubkey: SSH_BUG_PKAUTH");
- /* no explicit pkalg given */
- pkblob = packet_get_string(&blen);
- buffer_init(&b);
- buffer_append(&b, pkblob, blen);
- /* so we have to extract the pkalg from the pkblob */
- pkalg = buffer_get_string(&b, &alen);
- buffer_free(&b);
- } else {
- pkalg = packet_get_string(&alen);
- pkblob = packet_get_string(&blen);
- }
- pktype = key_type_from_name(pkalg);
- if (pktype == KEY_UNSPEC) {
- /* this is perfectly legal */
- log("userauth_pubkey: unsupported public key algorithm: %s",
- pkalg);
- goto done;
- }
- key = key_from_blob(pkblob, blen);
- if (key == NULL) {
- error("userauth_pubkey: cannot decode key: %s", pkalg);
- goto done;
- }
- if (key->type != pktype) {
- error("userauth_pubkey: type mismatch for decoded key "
- "(received %d, expected %d)", key->type, pktype);
- goto done;
- }
- if (have_sig) {
- sig = packet_get_string(&slen);
- packet_check_eom();
- buffer_init(&b);
- if (datafellows & SSH_OLD_SESSIONID) {
- buffer_append(&b, session_id2, session_id2_len);
- } else {
- buffer_put_string(&b, session_id2, session_id2_len);
- }
- /* reconstruct packet */
- buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
- buffer_put_cstring(&b, authctxt->user);
- buffer_put_cstring(&b,
- datafellows & SSH_BUG_PKSERVICE ?
- "ssh-userauth" :
- authctxt->service);
- if (datafellows & SSH_BUG_PKAUTH) {
- buffer_put_char(&b, have_sig);
- } else {
- buffer_put_cstring(&b, "publickey");
- buffer_put_char(&b, have_sig);
- buffer_put_cstring(&b, pkalg);
- }
- buffer_put_string(&b, pkblob, blen);
-#ifdef DEBUG_PK
- buffer_dump(&b);
-#endif
- /* test for correct signature */
- authenticated = 0;
- if (PRIVSEP(user_key_allowed(authctxt->pw, key)) &&
- PRIVSEP(key_verify(key, sig, slen, buffer_ptr(&b),
- buffer_len(&b))) == 1)
- authenticated = 1;
- buffer_clear(&b);
- xfree(sig);
- } else {
- debug("test whether pkalg/pkblob are acceptable");
- packet_check_eom();
-
- /* XXX fake reply and always send PK_OK ? */
- /*
- * XXX this allows testing whether a user is allowed
- * to login: if you happen to have a valid pubkey this
- * message is sent. the message is NEVER sent at all
- * if a user is not allowed to login. is this an
- * issue? -markus
- */
- if (PRIVSEP(user_key_allowed(authctxt->pw, key))) {
- packet_start(SSH2_MSG_USERAUTH_PK_OK);
- packet_put_string(pkalg, alen);
- packet_put_string(pkblob, blen);
- packet_send();
- packet_write_wait();
- authctxt->postponed = 1;
- }
- }
- if (authenticated != 1)
- auth_clear_options();
-done:
- debug2("userauth_pubkey: authenticated %d pkalg %s", authenticated, pkalg);
- if (key != NULL)
- key_free(key);
- xfree(pkalg);
- xfree(pkblob);
-#ifdef HAVE_CYGWIN
- if (check_nt_auth(0, authctxt->pw) == 0)
- return(0);
-#endif
- return authenticated;
-}
-
-static int
-userauth_hostbased(Authctxt *authctxt)
-{
- Buffer b;
- Key *key = NULL;
- char *pkalg, *cuser, *chost, *service;
- u_char *pkblob, *sig;
- u_int alen, blen, slen;
- int pktype;
- int authenticated = 0;
-
- if (!authctxt->valid) {
- debug2("userauth_hostbased: disabled because of invalid user");
- return 0;
- }
- pkalg = packet_get_string(&alen);
- pkblob = packet_get_string(&blen);
- chost = packet_get_string(NULL);
- cuser = packet_get_string(NULL);
- sig = packet_get_string(&slen);
-
- debug("userauth_hostbased: cuser %s chost %s pkalg %s slen %d",
- cuser, chost, pkalg, slen);
-#ifdef DEBUG_PK
- debug("signature:");
- buffer_init(&b);
- buffer_append(&b, sig, slen);
- buffer_dump(&b);
- buffer_free(&b);
-#endif
- pktype = key_type_from_name(pkalg);
- if (pktype == KEY_UNSPEC) {
- /* this is perfectly legal */
- log("userauth_hostbased: unsupported "
- "public key algorithm: %s", pkalg);
- goto done;
- }
- key = key_from_blob(pkblob, blen);
- if (key == NULL) {
- error("userauth_hostbased: cannot decode key: %s", pkalg);
- goto done;
- }
- if (key->type != pktype) {
- error("userauth_hostbased: type mismatch for decoded key "
- "(received %d, expected %d)", key->type, pktype);
- goto done;
- }
- service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" :
- authctxt->service;
- buffer_init(&b);
- buffer_put_string(&b, session_id2, session_id2_len);
- /* reconstruct packet */
- buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
- buffer_put_cstring(&b, authctxt->user);
- buffer_put_cstring(&b, service);
- buffer_put_cstring(&b, "hostbased");
- buffer_put_string(&b, pkalg, alen);
- buffer_put_string(&b, pkblob, blen);
- buffer_put_cstring(&b, chost);
- buffer_put_cstring(&b, cuser);
-#ifdef DEBUG_PK
- buffer_dump(&b);
-#endif
- /* test for allowed key and correct signature */
- authenticated = 0;
- if (PRIVSEP(hostbased_key_allowed(authctxt->pw, cuser, chost, key)) &&
- PRIVSEP(key_verify(key, sig, slen, buffer_ptr(&b),
- buffer_len(&b))) == 1)
- authenticated = 1;
-
- buffer_clear(&b);
-done:
- debug2("userauth_hostbased: authenticated %d", authenticated);
- if (key != NULL)
- key_free(key);
- xfree(pkalg);
- xfree(pkblob);
- xfree(cuser);
- xfree(chost);
- xfree(sig);
- return authenticated;
-}
-
-/* get current user */
-
-struct passwd*
-auth_get_user(void)
-{
- return (x_authctxt != NULL && x_authctxt->valid) ? x_authctxt->pw : NULL;
-}
-
#define DELIM ","
static char *
authmethods_get(void)
{
- Authmethod *method = NULL;
Buffer b;
char *list;
+ int i;
buffer_init(&b);
- for (method = authmethods; method->name != NULL; method++) {
- if (strcmp(method->name, "none") == 0)
+ for (i = 0; authmethods[i] != NULL; i++) {
+ if (strcmp(authmethods[i]->name, "none") == 0)
continue;
- if (method->enabled != NULL && *(method->enabled) != 0) {
+ if (authmethods[i]->enabled != NULL &&
+ *(authmethods[i]->enabled) != 0) {
if (buffer_len(&b) > 0)
buffer_append(&b, ",", 1);
- buffer_append(&b, method->name, strlen(method->name));
+ buffer_append(&b, authmethods[i]->name,
+ strlen(authmethods[i]->name));
}
}
buffer_append(&b, "\0", 1);
static Authmethod *
authmethod_lookup(const char *name)
{
- Authmethod *method = NULL;
+ int i;
+
if (name != NULL)
- for (method = authmethods; method->name != NULL; method++)
- if (method->enabled != NULL &&
- *(method->enabled) != 0 &&
- strcmp(name, method->name) == 0)
- return method;
- debug2("Unrecognized authentication method name: %s", name ? name : "NULL");
+ for (i = 0; authmethods[i] != NULL; i++)
+ if (authmethods[i]->enabled != NULL &&
+ *(authmethods[i]->enabled) != 0 &&
+ strcmp(name, authmethods[i]->name) == 0)
+ return authmethods[i];
+ debug2("Unrecognized authentication method name: %s",
+ name ? name : "NULL");
return NULL;
}