Add ipa_auth

To support IPA DS to Kerberos password migration a seperate
authentication target is added. It calls the Kerberos authentication
target and in the case of a 'Preauthentication Error' the LDAP
authentication target. On success the Kerberos target is called again to
request the TGT.

4 files changed, 350 insertions, 1 deletions

diff --git a/server/providers/ipa/ipa_auth.c b/server/providers/ipa/ipa_auth.c
new file mode 100644
index 00000000..9f9a48e2
--- /dev/null
+++ b/server/providers/ipa/ipa_auth.c
@@ -0,0 +1,313 @@
+/*
+    SSSD
+
+    IPA Backend Module -- Authentication
+
+    Authors:
+        Sumit Bose <sbose@redhat.com>
+
+    Copyright (C) 2009 Red Hat
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <sys/param.h>
+#include <security/pam_modules.h>
+
+#include "util/util.h"
+#include "providers/ldap/ldap_common.h"
+#include "providers/ldap/sdap_async.h"
+#include "providers/krb5/krb5_auth.h"
+#include "providers/ipa/ipa_common.h"
+
+struct ipa_auth_ctx {
+    struct sdap_auth_ctx *sdap_auth_ctx;
+    struct krb5_ctx *krb5_ctx;
+    struct be_req *be_req;
+    be_async_callback_t callback;
+    void *pvt;
+    bool password_migration;
+
+    int dp_err_type;
+    int errnum;
+    char *errstr;
+};
+
+static void ipa_auth_reply(struct ipa_auth_ctx *ipa_auth_ctx)
+{
+    struct pam_data *pd;
+    struct be_req *be_req = ipa_auth_ctx->be_req;
+    be_req->fn = ipa_auth_ctx->callback;
+    be_req->pvt = ipa_auth_ctx->pvt;
+    be_req->be_ctx->bet_info[BET_AUTH].pvt_bet_data = ipa_auth_ctx->krb5_ctx;
+    pd = talloc_get_type(be_req->req_data, struct pam_data);
+    int dp_err_type = ipa_auth_ctx->dp_err_type;
+    char *errstr = ipa_auth_ctx->errstr;
+
+    talloc_zfree(ipa_auth_ctx);
+    DEBUG(9, ("sending [%d] [%d] [%s].\n", dp_err_type, pd->pam_status,
+                                           errstr));
+
+    be_req->fn(be_req, dp_err_type, pd->pam_status, errstr);
+}
+
+struct ipa_auth_handler_state {
+    struct tevent_context *ev;
+
+    int dp_err_type;
+    int errnum;
+    char *errstr;
+};
+
+static void ipa_auth_handler_callback(struct be_req *be_req,
+                                   int dp_err_type,
+                                   int errnum,
+                                   const char *errstr);
+
+static struct tevent_req *ipa_auth_handler_send(TALLOC_CTX *memctx,
+                                            struct tevent_context *ev,
+                                            struct be_req *be_req,
+                                            be_req_fn_t auth_handler)
+{
+    struct ipa_auth_handler_state *state;
+    struct tevent_req *req;
+
+    req = tevent_req_create(memctx, &state, struct ipa_auth_handler_state);
+    if (req == NULL) {
+        DEBUG(1, ("tevent_req_create failed.\n"));
+        return NULL;
+    }
+
+    state->ev = ev;
+
+    be_req->fn = ipa_auth_handler_callback;
+    be_req->pvt = req;
+
+    auth_handler(be_req);
+
+    return req;
+}
+
+static void ipa_auth_handler_callback(struct be_req *be_req,
+                                   int dp_err_type,
+                                   int errnum,
+                                   const char *errstr)
+{
+    struct tevent_req *req = talloc_get_type(be_req->pvt, struct tevent_req);
+    struct ipa_auth_handler_state *state = tevent_req_data(req,
+                                                 struct ipa_auth_handler_state);
+
+    DEBUG(9, ("received from handler [%d] [%d] [%s].\n", dp_err_type, errnum,
+                                                         errstr));
+    state->dp_err_type = dp_err_type;
+    state->errnum = errnum;
+    state->errstr = talloc_strdup(state, errstr);
+
+    tevent_req_post(req, state->ev);
+    tevent_req_done(req);
+    return;
+}
+
+static int ipa_auth_handler_recv(struct tevent_req *req, TALLOC_CTX *memctx,
+                              int *dp_err_type, int *errnum,
+                              char **errstr)
+{
+    struct ipa_auth_handler_state *state = tevent_req_data(req,
+                                                 struct ipa_auth_handler_state);
+    enum tevent_req_state tstate;
+    uint64_t err;
+
+    if (tevent_req_is_error(req, &tstate, &err)) {
+        if (err) return err;
+        return EIO;
+    }
+
+    *dp_err_type = state->dp_err_type;
+    *errnum = state->errnum;
+    *errstr = talloc_steal(memctx, state->errstr);
+
+    return EOK;
+}
+
+
+static void ipa_auth_handler_done(struct tevent_req *req);
+static void ipa_auth_ldap_done(struct tevent_req *req);
+static void ipa_auth_handler_retry_done(struct tevent_req *req);
+
+void ipa_auth(struct be_req *be_req)
+{
+    struct tevent_req *req;
+    struct ipa_auth_ctx *ipa_auth_ctx;
+    struct sdap_id_ctx *sdap_id_ctx;
+
+    ipa_auth_ctx = talloc_zero(be_req, struct ipa_auth_ctx);
+    if (ipa_auth_ctx == NULL) {
+        DEBUG(1, ("talloc failed.\n"));
+        be_req->fn(be_req, DP_ERR_FATAL, PAM_SYSTEM_ERR, NULL);
+    }
+
+    ipa_auth_ctx->callback = be_req->fn;
+    ipa_auth_ctx->pvt = be_req->pvt;
+
+    ipa_auth_ctx->be_req = be_req;
+
+    ipa_auth_ctx->sdap_auth_ctx = talloc_zero(ipa_auth_ctx,
+                                              struct sdap_auth_ctx);
+    if (ipa_auth_ctx->sdap_auth_ctx == NULL) {
+        DEBUG(1, ("talloc failed.\n"));
+        goto fail;
+    }
+
+    sdap_id_ctx = talloc_get_type(
+                              be_req->be_ctx->bet_info[BET_ID].pvt_bet_data,
+                              struct sdap_id_ctx);
+    ipa_auth_ctx->sdap_auth_ctx->be = sdap_id_ctx->be;
+    ipa_auth_ctx->sdap_auth_ctx->opts = sdap_id_ctx->opts;
+
+    ipa_auth_ctx->krb5_ctx = talloc_get_type(
+                              be_req->be_ctx->bet_info[BET_AUTH].pvt_bet_data,
+                              struct krb5_ctx);
+
+/* TODO: make password_migration configurable */
+    ipa_auth_ctx->password_migration = true;
+
+    ipa_auth_ctx->dp_err_type = DP_ERR_FATAL;
+    ipa_auth_ctx->errnum = EIO;
+    ipa_auth_ctx->errstr = NULL;
+
+    req = ipa_auth_handler_send(ipa_auth_ctx, be_req->be_ctx->ev, be_req,
+                                krb5_pam_handler);
+    if (req == NULL) {
+        DEBUG(1, ("ipa_auth_handler_send failed.\n"));
+        goto fail;
+    }
+
+    tevent_req_set_callback(req, ipa_auth_handler_done, ipa_auth_ctx);
+    return;
+
+fail:
+    ipa_auth_reply(ipa_auth_ctx);
+}
+
+static void ipa_auth_handler_done(struct tevent_req *req)
+{
+    struct ipa_auth_ctx *ipa_auth_ctx = tevent_req_callback_data(req,
+                                                           struct ipa_auth_ctx);
+    struct pam_data *pd;
+    struct be_req *be_req;
+    int ret;
+
+    be_req = ipa_auth_ctx->be_req;
+    pd = talloc_get_type(be_req->req_data, struct pam_data);
+
+    ret = ipa_auth_handler_recv(req, ipa_auth_ctx, &ipa_auth_ctx->dp_err_type,
+                                &ipa_auth_ctx->errnum, &ipa_auth_ctx->errstr);
+    talloc_zfree(req);
+    if (ret != EOK) {
+        DEBUG(1, ("ipa_auth_handler request failed.\n"));
+        pd->pam_status = PAM_SYSTEM_ERR;
+        goto done;
+    }
+    if (ipa_auth_ctx->dp_err_type != DP_ERR_OK) {
+        pd->pam_status = ipa_auth_ctx->errnum;
+        goto done;
+    }
+
+    if (ipa_auth_ctx->password_migration && pd->pam_status == PAM_CRED_ERR) {
+        DEBUG(1, ("Assuming Kerberos password is missing, "
+                  "starting password migration.\n"));
+        be_req->be_ctx->bet_info[BET_AUTH].pvt_bet_data =
+                                                    ipa_auth_ctx->sdap_auth_ctx;
+        req = ipa_auth_handler_send(ipa_auth_ctx, be_req->be_ctx->ev, be_req,
+                                    sdap_pam_auth_handler);
+        if (req == NULL) {
+            DEBUG(1, ("ipa_auth_ldap_send failed.\n"));
+            goto done;
+        }
+
+        tevent_req_set_callback(req, ipa_auth_ldap_done, ipa_auth_ctx);
+        return;
+    }
+
+done:
+    ipa_auth_reply(ipa_auth_ctx);
+}
+
+static void ipa_auth_ldap_done(struct tevent_req *req)
+{
+    struct ipa_auth_ctx *ipa_auth_ctx = tevent_req_callback_data(req,
+                                                           struct ipa_auth_ctx);
+    struct pam_data *pd;
+    struct be_req *be_req;
+    int ret;
+
+    be_req = ipa_auth_ctx->be_req;
+    pd = talloc_get_type(be_req->req_data, struct pam_data);
+
+    ret = ipa_auth_handler_recv(req, ipa_auth_ctx, &ipa_auth_ctx->dp_err_type,
+                                &ipa_auth_ctx->errnum, &ipa_auth_ctx->errstr);
+    talloc_zfree(req);
+    if (ret != EOK) {
+        DEBUG(1, ("ipa_auth_handler request failed.\n"));
+        pd->pam_status = PAM_SYSTEM_ERR;
+        goto done;
+    }
+    if (ipa_auth_ctx->dp_err_type != DP_ERR_OK) {
+        pd->pam_status = ipa_auth_ctx->errnum;
+        goto done;
+    }
+
+    if (pd->pam_status == PAM_SUCCESS) {
+        DEBUG(1, ("LDAP authentication succeded, "
+                  "trying Kerberos authentication again.\n"));
+        be_req->be_ctx->bet_info[BET_AUTH].pvt_bet_data = ipa_auth_ctx->krb5_ctx;
+        req = ipa_auth_handler_send(ipa_auth_ctx, be_req->be_ctx->ev, be_req,
+                                    krb5_pam_handler);
+        if (req == NULL) {
+            DEBUG(1, ("ipa_auth_ldap_send failed.\n"));
+            goto done;
+        }
+
+        tevent_req_set_callback(req, ipa_auth_handler_retry_done, ipa_auth_ctx);
+        return;
+    }
+
+done:
+    ipa_auth_reply(ipa_auth_ctx);
+}
+
+static void ipa_auth_handler_retry_done(struct tevent_req *req)
+{
+    struct ipa_auth_ctx *ipa_auth_ctx = tevent_req_callback_data(req,
+                                                           struct ipa_auth_ctx);
+    struct pam_data *pd;
+    struct be_req *be_req;
+    int ret;
+
+    be_req = ipa_auth_ctx->be_req;
+    pd = talloc_get_type(be_req->req_data, struct pam_data);
+
+    ret = ipa_auth_handler_recv(req, ipa_auth_ctx, &ipa_auth_ctx->dp_err_type,
+                                &ipa_auth_ctx->errnum, &ipa_auth_ctx->errstr);
+    talloc_zfree(req);
+    if (ret != EOK) {
+        DEBUG(1, ("ipa_auth_handler request failed.\n"));
+        pd->pam_status = PAM_SYSTEM_ERR;
+    }
+    if (ipa_auth_ctx->dp_err_type != DP_ERR_OK) {
+        pd->pam_status = ipa_auth_ctx->errnum;
+    }
+
+    ipa_auth_reply(ipa_auth_ctx);
+}
diff --git a/server/providers/ipa/ipa_auth.h b/server/providers/ipa/ipa_auth.h
new file mode 100644
index 00000000..3079bbd1
--- /dev/null
+++ b/server/providers/ipa/ipa_auth.h
@@ -0,0 +1,32 @@
+/*
+    SSSD
+
+    IPA Backend Module -- Authentication
+
+    Authors:
+        Sumit Bose <sbose@redhat.com>
+
+    Copyright (C) 2009 Red Hat
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef _IPA_AUTH_H_
+#define _IPA_AUTH_H_
+
+#include "providers/dp_backend.h"
+
+void ipa_auth(struct be_req *be_req);
+
+#endif /* _IPA_AUTH_H_ */
diff --git a/server/providers/ipa/ipa_init.c b/server/providers/ipa/ipa_init.c
index 1b93e14d..70145287 100644
--- a/server/providers/ipa/ipa_init.c
+++ b/server/providers/ipa/ipa_init.c
@@ -29,6 +29,7 @@
 
 #include "providers/ipa/ipa_common.h"
 #include "providers/krb5/krb5_auth.h"
+#include "providers/ipa/ipa_auth.h"
 #include "providers/ipa/ipa_access.h"
 #include "providers/ipa/ipa_timerules.h"
 
@@ -41,7 +42,7 @@ struct bet_ops ipa_id_ops = {
 };
 
 struct bet_ops ipa_auth_ops = {
-    .handler = krb5_pam_handler,
+    .handler = ipa_auth,
     .finalize = NULL,
 };
 
diff --git a/server/providers/krb5/krb5_child.c b/server/providers/krb5/krb5_child.c
index 5a1bf374..f7809d2c 100644
--- a/server/providers/krb5/krb5_child.c
+++ b/server/providers/krb5/krb5_child.c
@@ -582,6 +582,9 @@ static errno_t tgt_req_child(int fd, struct krb5_req *kr)
             case KRB5KDC_ERR_KEY_EXP:
                     pam_status = PAM_AUTHTOK_EXPIRED;
                     break;
+            case KRB5KDC_ERR_PREAUTH_FAILED:
+                    pam_status = PAM_CRED_ERR;
+                    break;
             default:
                     pam_status = PAM_SYSTEM_ERR;
         }