added kerberos backend with tevent_req event handling

1 files changed, 179 insertions, 0 deletions

diff --git a/server/providers/krb5/tgt_req_child.c b/server/providers/krb5/tgt_req_child.c
new file mode 100644
index 00000000..edb3d180
--- /dev/null
+++ b/server/providers/krb5/tgt_req_child.c
@@ -0,0 +1,179 @@
+/*
+    SSSD
+
+    Kerberos 5 Backend Module -- tgt_req child
+
+    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 <krb5/krb5.h>
+#include <sys/types.h>
+
+#include <security/pam_modules.h>
+
+#include "util/util.h"
+#include "providers/dp_backend.h"
+#include "providers/krb5/krb5_auth.h"
+
+static int pack_response_packet(uint8_t *buf, int status, int type,
+                                const char *data)
+{
+    int len;
+    int p=0;
+
+    if ((3*sizeof(int32_t) + strlen(data)+1) > MAX_CHILD_MSG_SIZE) {
+        return -1;
+    }
+
+    ((int32_t *)(&buf[p]))[0] = status;
+    p += sizeof(int32_t);
+
+    ((int32_t *)(&buf[p]))[0] = type;
+    p += sizeof(int32_t);
+
+    len = strlen(data)+1;
+    ((int32_t *)(&buf[p]))[0] = len;
+    p += sizeof(int32_t);
+
+    memcpy(&buf[p], data, len);
+    p += len;
+
+    return p;
+}
+
+void tgt_req_child(int fd, struct krb5_req *kr)
+{
+    int ret;
+    krb5_error_code kerr = 0;
+    char *pass_str = NULL;
+    uint8_t buf[MAX_CHILD_MSG_SIZE];
+    int size = 0;
+    const char *cc_name;
+    char *env;
+    const char *krb5_error_msg;
+
+    ret = setgid(kr->pd->gr_gid);
+    if (ret == -1) {
+        DEBUG(1, ("setgid failed [%d][%s].\n", errno, strerror(errno)));
+        _exit(-1);
+    }
+
+    ret = setuid(kr->pd->pw_uid);
+    if (ret == -1) {
+        DEBUG(1, ("setuid failed [%d][%s].\n", errno, strerror(errno)));
+        _exit(-1);
+    }
+
+    ret = setegid(kr->pd->gr_gid);
+    if (ret == -1) {
+        DEBUG(1, ("setegid failed [%d][%s].\n", errno, strerror(errno)));
+        _exit(-1);
+    }
+
+    ret = seteuid(kr->pd->pw_uid);
+    if (ret == -1) {
+        DEBUG(1, ("seteuid failed [%d][%s].\n", errno, strerror(errno)));
+        _exit(-1);
+    }
+
+    pass_str = talloc_strndup(kr, (const char *) kr->pd->authtok,
+                              kr->pd->authtok_size);
+    if (pass_str == NULL) {
+        DEBUG(1, ("talloc_strndup failed.\n"));
+        _exit(-1);
+    }
+
+    kerr = krb5_get_init_creds_password(kr->ctx, kr->creds, kr->princ,
+                                        pass_str, NULL, NULL, 0, NULL,
+                                        kr->options);
+    if (kerr != 0) {
+        KRB5_DEBUG(1, kerr);
+        goto childfailed;
+    }
+
+    memset(pass_str, 0, kr->pd->authtok_size);
+    talloc_free(pass_str);
+    memset(kr->pd->authtok, 0, kr->pd->authtok_size);
+
+    kerr = krb5_cc_default(kr->ctx, &kr->cc);
+    if (kerr != 0) {
+        KRB5_DEBUG(1, kerr);
+        goto childfailed;
+    }
+
+    kerr = krb5_cc_initialize(kr->ctx, kr->cc, kr->princ);
+    if (kerr != 0) {
+        KRB5_DEBUG(1, kerr);
+        goto childfailed;
+    }
+
+    kerr = krb5_cc_store_cred(kr->ctx, kr->cc, kr->creds);
+    if (kerr != 0) {
+        KRB5_DEBUG(1, kerr);
+        krb5_cc_destroy(kr->ctx, kr->cc);
+        goto childfailed;
+    }
+
+    cc_name = krb5_cc_get_name(kr->ctx, kr->cc);
+    if (cc_name == NULL) {
+        DEBUG(1, ("krb5_cc_get_name failed.\n"));
+        krb5_cc_destroy(kr->ctx, kr->cc);
+        _exit(-1);
+    }
+
+    env = talloc_asprintf(kr, "%s=%s",CCACHE_ENV_NAME, cc_name);
+    if (env == NULL) {
+        DEBUG(1, ("talloc_asprintf failed.\n"));
+        krb5_cc_destroy(kr->ctx, kr->cc);
+        _exit(-1);
+    }
+
+    size = pack_response_packet(buf, PAM_SUCCESS, PAM_ENV_ITEM, env);
+    if (size < 0) {
+        DEBUG(1, ("failed to create response message.\n"));
+        krb5_cc_destroy(kr->ctx, kr->cc);
+        _exit(-1);
+    }
+
+    kerr = 0;
+
+childfailed:
+    if (kerr != 0 ) {
+        krb5_error_msg = krb5_get_error_message(krb5_error_ctx, kerr);
+        size = pack_response_packet(buf, PAM_SYSTEM_ERR, PAM_USER_INFO,
+                                    krb5_error_msg);
+        if (size < 0) {
+            DEBUG(1, ("failed to create response message.\n"));
+            krb5_cc_destroy(kr->ctx, kr->cc);
+            _exit(-1);
+        }
+        krb5_free_error_message(krb5_error_ctx, krb5_error_msg);
+    }
+
+    ret = write(fd, buf, size);
+    if (ret == -1) {
+        DEBUG(1, ("write failed [%d][%s].\n", errno, strerror(errno)));
+        krb5_cc_destroy(kr->ctx, kr->cc);
+        _exit(ret);
+    }
+
+    krb5_cc_close(kr->ctx, kr->cc);
+
+
+    _exit(0);
+}