diff options
Diffstat (limited to 'src/providers/krb5/krb5_auth.c')
| -rw-r--r-- | src/providers/krb5/krb5_auth.c | 1193 |
1 files changed, 1193 insertions, 0 deletions
diff --git a/src/providers/krb5/krb5_auth.c b/src/providers/krb5/krb5_auth.c new file mode 100644 index 000000000..a2dadc808 --- /dev/null +++ b/src/providers/krb5/krb5_auth.c @@ -0,0 +1,1193 @@ +/* + SSSD + + Kerberos 5 Backend Module + + 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 <errno.h> +#include <sys/time.h> + +#include <sys/types.h> +#include <sys/wait.h> +#include <pwd.h> +#include <sys/stat.h> + +#include <security/pam_modules.h> + +#include "util/util.h" +#include "util/find_uid.h" +#include "db/sysdb.h" +#include "providers/child_common.h" +#include "providers/krb5/krb5_auth.h" +#include "providers/krb5/krb5_utils.h" + +#ifndef SSSD_LIBEXEC_PATH +#error "SSSD_LIBEXEC_PATH not defined" +#else +#define KRB5_CHILD SSSD_LIBEXEC_PATH"/krb5_child" +#endif + +static errno_t add_krb5_env(struct dp_option *opts, const char *ccname, + struct pam_data *pd) +{ + int ret; + const char *dummy; + char *env; + TALLOC_CTX *tmp_ctx = NULL; + + tmp_ctx = talloc_new(NULL); + if (tmp_ctx == NULL) { + DEBUG(1, ("talloc_new failed.\n")); + return ENOMEM; + } + + if (ccname != NULL) { + env = talloc_asprintf(tmp_ctx, "%s=%s",CCACHE_ENV_NAME, ccname); + if (env == NULL) { + DEBUG(1, ("talloc_asprintf failed.\n")); + ret = ENOMEM; + goto done; + } + ret = pam_add_response(pd, SSS_PAM_ENV_ITEM, strlen(env)+1, + (uint8_t *) env); + if (ret != EOK) { + DEBUG(1, ("pam_add_response failed.\n")); + goto done; + } + } + + dummy = dp_opt_get_cstring(opts, KRB5_REALM); + if (dummy != NULL) { + env = talloc_asprintf(tmp_ctx, "%s=%s", SSSD_KRB5_REALM, dummy); + if (env == NULL) { + DEBUG(1, ("talloc_asprintf failed.\n")); + ret = ENOMEM; + goto done; + } + ret = pam_add_response(pd, SSS_PAM_ENV_ITEM, strlen(env)+1, + (uint8_t *) env); + if (ret != EOK) { + DEBUG(1, ("pam_add_response failed.\n")); + goto done; + } + } + + dummy = dp_opt_get_cstring(opts, KRB5_KDC); + if (dummy != NULL) { + env = talloc_asprintf(tmp_ctx, "%s=%s", SSSD_KRB5_KDC, dummy); + if (env == NULL) { + DEBUG(1, ("talloc_asprintf failed.\n")); + ret = ENOMEM; + goto done; + } + ret = pam_add_response(pd, SSS_PAM_ENV_ITEM, strlen(env)+1, + (uint8_t *) env); + if (ret != EOK) { + DEBUG(1, ("pam_add_response failed.\n")); + goto done; + } + } + + ret = EOK; + +done: + talloc_free(tmp_ctx); + return ret; +} + +static errno_t check_if_ccache_file_is_used(uid_t uid, const char *ccname, + bool *result) +{ + int ret; + size_t offset = 0; + struct stat stat_buf; + const char *filename; + bool active; + + *result = false; + + if (ccname == NULL || *ccname == '\0') { + return EINVAL; + } + + if (strncmp(ccname, "FILE:", 5) == 0) { + offset = 5; + } + + filename = ccname + offset; + + if (filename[0] != '/') { + DEBUG(1, ("Only absolute path names are allowed")); + return EINVAL; + } + + ret = lstat(filename, &stat_buf); + + if (ret == -1 && errno != ENOENT) { + DEBUG(1, ("stat failed [%d][%s].\n", errno, strerror(errno))); + return errno; + } else if (ret == EOK) { + if (stat_buf.st_uid != uid) { + DEBUG(1, ("Cache file [%s] exists, but is owned by [%d] instead of " + "[%d].\n", filename, stat_buf.st_uid, uid)); + return EINVAL; + } + + if (!S_ISREG(stat_buf.st_mode)) { + DEBUG(1, ("Cache file [%s] exists, but is not a regular file.\n", + filename)); + return EINVAL; + } + } + + ret = check_if_uid_is_active(uid, &active); + if (ret != EOK) { + DEBUG(1, ("check_if_uid_is_active failed.\n")); + return ret; + } + + if (!active) { + DEBUG(5, ("User [%d] is not active\n", uid)); + } else { + DEBUG(9, ("User [%d] is still active, reusing ccache file [%s].\n", + uid, filename)); + *result = true; + } + return EOK; +} + +struct krb5_save_ccname_state { + struct tevent_context *ev; + struct sysdb_ctx *sysdb; + struct sysdb_handle *handle; + struct sss_domain_info *domain; + const char *name; + struct sysdb_attrs *attrs; +}; + +static void krb5_save_ccname_trans(struct tevent_req *subreq); +static void krb5_set_user_attr_done(struct tevent_req *subreq); + +static struct tevent_req *krb5_save_ccname_send(TALLOC_CTX *mem_ctx, + struct tevent_context *ev, + struct sysdb_ctx *sysdb, + struct sss_domain_info *domain, + const char *name, + const char *ccname) +{ + struct tevent_req *req; + struct tevent_req *subreq; + struct krb5_save_ccname_state *state; + int ret; + + if (name == NULL || ccname == NULL) { + DEBUG(1, ("Missing user or ccache name.\n")); + return NULL; + } + + req = tevent_req_create(mem_ctx, &state, struct krb5_save_ccname_state); + if (req == NULL) { + DEBUG(1, ("tevent_req_create failed.\n")); + return NULL; + } + + state->ev = ev; + state->sysdb = sysdb; + state->handle = NULL; + state->domain = domain; + state->name = name; + + state->attrs = sysdb_new_attrs(state); + ret = sysdb_attrs_add_string(state->attrs, SYSDB_CCACHE_FILE, ccname); + if (ret != EOK) { + DEBUG(1, ("sysdb_attrs_add_string failed.\n")); + goto failed; + } + + subreq = sysdb_transaction_send(state, ev, sysdb); + if (subreq == NULL) { + goto failed; + } + tevent_req_set_callback(subreq, krb5_save_ccname_trans, req); + + return req; + +failed: + talloc_free(req); + return NULL; +} + +static void krb5_save_ccname_trans(struct tevent_req *subreq) +{ + struct tevent_req *req = tevent_req_callback_data(subreq, + struct tevent_req); + struct krb5_save_ccname_state *state = tevent_req_data(req, + struct krb5_save_ccname_state); + int ret; + + ret = sysdb_transaction_recv(subreq, state, &state->handle); + talloc_zfree(subreq); + if (ret != EOK) { + DEBUG(6, ("Error: %d (%s)\n", ret, strerror(ret))); + tevent_req_error(req, ret); + return; + } + + subreq = sysdb_set_user_attr_send(state, state->ev, state->handle, + state->domain, state->name, + state->attrs, SYSDB_MOD_REP); + if (subreq == NULL) { + DEBUG(6, ("Error: Out of memory\n")); + tevent_req_error(req, ENOMEM); + return; + } + tevent_req_set_callback(subreq, krb5_set_user_attr_done, req); +} + +static void krb5_set_user_attr_done(struct tevent_req *subreq) +{ + struct tevent_req *req = tevent_req_callback_data(subreq, + struct tevent_req); + struct krb5_save_ccname_state *state = tevent_req_data(req, + struct krb5_save_ccname_state); + int ret; + + ret = sysdb_set_user_attr_recv(subreq); + talloc_zfree(subreq); + if (ret != EOK) { + DEBUG(6, ("Error: %d (%s)\n", ret, strerror(ret))); + tevent_req_error(req, ret); + return; + } + + subreq = sysdb_transaction_commit_send(state, state->ev, state->handle); + if (subreq == NULL) { + DEBUG(6, ("Error: Out of memory\n")); + tevent_req_error(req, ENOMEM); + return; + } + tevent_req_set_callback(subreq, sysdb_transaction_complete, req); + return; +} + +int krb5_save_ccname_recv(struct tevent_req *req) +{ + TEVENT_REQ_RETURN_ON_ERROR(req); + + return EOK; +} + +errno_t create_send_buffer(struct krb5child_req *kr, struct io_buffer **io_buf) +{ + struct io_buffer *buf; + size_t rp; + const char *keytab; + uint32_t validate; + + keytab = dp_opt_get_cstring(kr->krb5_ctx->opts, KRB5_KEYTAB); + if (keytab == NULL) { + DEBUG(1, ("Missing keytab option.\n")); + return EINVAL; + } + + validate = dp_opt_get_bool(kr->krb5_ctx->opts, KRB5_VALIDATE) ? 1 : 0; + + buf = talloc(kr, struct io_buffer); + if (buf == NULL) { + DEBUG(1, ("talloc failed.\n")); + return ENOMEM; + } + + buf->size = 9*sizeof(uint32_t) + strlen(kr->pd->upn) + strlen(kr->ccname) + + strlen(keytab) + + kr->pd->authtok_size; + if (kr->pd->cmd == SSS_PAM_CHAUTHTOK) { + buf->size += sizeof(uint32_t) + kr->pd->newauthtok_size; + } + + buf->data = talloc_size(kr, buf->size); + if (buf->data == NULL) { + DEBUG(1, ("talloc_size failed.\n")); + talloc_free(buf); + return ENOMEM; + } + + rp = 0; + COPY_UINT32(&buf->data[rp], &kr->pd->cmd, rp); + COPY_UINT32(&buf->data[rp], &kr->pd->pw_uid, rp); + COPY_UINT32(&buf->data[rp], &kr->pd->gr_gid, rp); + COPY_UINT32(&buf->data[rp], &validate, rp); + COPY_UINT32(&buf->data[rp], &kr->is_offline, rp); + + COPY_UINT32_VALUE(&buf->data[rp], strlen(kr->pd->upn), rp); + COPY_MEM(&buf->data[rp], kr->pd->upn, rp, strlen(kr->pd->upn)); + + COPY_UINT32_VALUE(&buf->data[rp], strlen(kr->ccname), rp); + COPY_MEM(&buf->data[rp], kr->ccname, rp, strlen(kr->ccname)); + + COPY_UINT32_VALUE(&buf->data[rp], strlen(keytab), rp); + COPY_MEM(&buf->data[rp], keytab, rp, strlen(keytab)); + + COPY_UINT32(&buf->data[rp], &kr->pd->authtok_size, rp); + COPY_MEM(&buf->data[rp], kr->pd->authtok, rp, kr->pd->authtok_size); + + if (kr->pd->cmd == SSS_PAM_CHAUTHTOK) { + COPY_UINT32(&buf->data[rp], &kr->pd->newauthtok_size, rp); + COPY_MEM(&buf->data[rp], kr->pd->newauthtok, + rp, kr->pd->newauthtok_size); + } + + *io_buf = buf; + + return EOK; +} + +static struct krb5_ctx *get_krb5_ctx(struct be_req *be_req) +{ + struct pam_data *pd; + + pd = talloc_get_type(be_req->req_data, struct pam_data); + + switch (pd->cmd) { + case SSS_PAM_AUTHENTICATE: + return talloc_get_type(be_req->be_ctx->bet_info[BET_AUTH].pvt_bet_data, + struct krb5_ctx); + break; + case SSS_PAM_CHAUTHTOK: + case SSS_PAM_CHAUTHTOK_PRELIM: + return talloc_get_type(be_req->be_ctx->bet_info[BET_CHPASS].pvt_bet_data, + struct krb5_ctx); + break; + default: + DEBUG(1, ("Unsupported PAM task.\n")); + return NULL; + } +} + +static void krb_reply(struct be_req *req, int dp_err, int result); + +static void krb5_child_timeout(struct tevent_context *ev, + struct tevent_timer *te, + struct timeval tv, void *pvt) +{ + struct krb5child_req *kr = talloc_get_type(pvt, struct krb5child_req); + struct be_req *be_req = kr->req; + struct pam_data *pd = kr->pd; + int ret; + + if (kr->timeout_handler == NULL) { + return; + } + + DEBUG(9, ("timeout for child [%d] reached.\n", kr->child_pid)); + + ret = kill(kr->child_pid, SIGKILL); + if (ret == -1) { + DEBUG(1, ("kill failed [%d][%s].\n", errno, strerror(errno))); + } + + talloc_zfree(kr); + + pd->pam_status = PAM_AUTHINFO_UNAVAIL; + be_mark_offline(be_req->be_ctx); + + krb_reply(be_req, DP_ERR_OFFLINE, pd->pam_status); +} + +static errno_t activate_child_timeout_handler(struct krb5child_req *kr) +{ + struct timeval tv; + + tv = tevent_timeval_current(); + tv = tevent_timeval_add(&tv, + dp_opt_get_int(kr->krb5_ctx->opts, + KRB5_AUTH_TIMEOUT), + 0); + kr->timeout_handler = tevent_add_timer(kr->req->be_ctx->ev, kr, tv, + krb5_child_timeout, kr); + if (kr->timeout_handler == NULL) { + DEBUG(1, ("tevent_add_timer failed.\n")); + return ENOMEM; + } + + return EOK; +} + +static int krb5_cleanup(void *ptr) +{ + struct krb5child_req *kr = talloc_get_type(ptr, struct krb5child_req); + + if (kr == NULL) return EOK; + + child_cleanup(kr->read_from_child_fd, kr->write_to_child_fd); + memset(kr, 0, sizeof(struct krb5child_req)); + + return EOK; +} + +static errno_t krb5_setup(struct be_req *req, struct krb5child_req **krb5_req) +{ + struct krb5child_req *kr = NULL; + struct krb5_ctx *krb5_ctx; + struct pam_data *pd; + errno_t err; + + pd = talloc_get_type(req->req_data, struct pam_data); + + krb5_ctx = get_krb5_ctx(req); + if (krb5_ctx == NULL) { + DEBUG(1, ("Kerberos context not available.\n")); + err = EINVAL; + goto failed; + } + + kr = talloc_zero(req, struct krb5child_req); + if (kr == NULL) { + DEBUG(1, ("talloc failed.\n")); + err = ENOMEM; + goto failed; + } + kr->read_from_child_fd = -1; + kr->write_to_child_fd = -1; + kr->is_offline = false; + kr->active_ccache_present = true; + talloc_set_destructor((TALLOC_CTX *) kr, krb5_cleanup); + + kr->pd = pd; + kr->req = req; + kr->krb5_ctx = krb5_ctx; + + *krb5_req = kr; + + return EOK; + +failed: + talloc_zfree(kr); + + return err; +} + +static errno_t fork_child(struct krb5child_req *kr) +{ + int pipefd_to_child[2]; + int pipefd_from_child[2]; + pid_t pid; + int ret; + errno_t err; + + ret = pipe(pipefd_from_child); + if (ret == -1) { + err = errno; + DEBUG(1, ("pipe failed [%d][%s].\n", errno, strerror(errno))); + return err; + } + ret = pipe(pipefd_to_child); + if (ret == -1) { + err = errno; + DEBUG(1, ("pipe failed [%d][%s].\n", errno, strerror(errno))); + return err; + } + + pid = fork(); + + if (pid == 0) { /* child */ + /* We need to keep the root privileges to read the keytab file if + * validation is enabled, otherwise we can drop them here and run + * krb5_child with user privileges. + * If authtok_size is zero we are offline and want to create an empty + * ccache file. In this case we can drop the privileges, too. */ + if (!dp_opt_get_bool(kr->krb5_ctx->opts, KRB5_VALIDATE) || + kr->pd->authtok_size == 0) { + ret = become_user(kr->pd->pw_uid, kr->pd->gr_gid); + if (ret != EOK) { + DEBUG(1, ("become_user failed.\n")); + return ret; + } + } + + err = exec_child(kr, + pipefd_to_child, pipefd_from_child, + KRB5_CHILD, kr->krb5_ctx->child_debug_fd); + if (err != EOK) { + DEBUG(1, ("Could not exec LDAP child: [%d][%s].\n", + err, strerror(err))); + return err; + } + } else if (pid > 0) { /* parent */ + kr->child_pid = pid; + kr->read_from_child_fd = pipefd_from_child[0]; + close(pipefd_from_child[1]); + kr->write_to_child_fd = pipefd_to_child[1]; + close(pipefd_to_child[0]); + fd_nonblocking(kr->read_from_child_fd); + fd_nonblocking(kr->write_to_child_fd); + + err = activate_child_timeout_handler(kr); + if (err != EOK) { + DEBUG(1, ("activate_child_timeout_handler failed.\n")); + } + + } else { /* error */ + err = errno; + DEBUG(1, ("fork failed [%d][%s].\n", errno, strerror(errno))); + return err; + } + + return EOK; +} + +struct handle_child_state { + struct tevent_context *ev; + struct krb5child_req *kr; + uint8_t *buf; + ssize_t len; +}; + +static void handle_child_step(struct tevent_req *subreq); +static void handle_child_done(struct tevent_req *subreq); + +static struct tevent_req *handle_child_send(TALLOC_CTX *mem_ctx, + struct tevent_context *ev, + struct krb5child_req *kr) +{ + struct tevent_req *req, *subreq; + struct handle_child_state *state; + struct io_buffer *buf; + int ret; + + req = tevent_req_create(mem_ctx, &state, struct handle_child_state); + if (req == NULL) { + return NULL; + } + + state->ev = ev; + state->kr = kr; + state->buf = NULL; + state->len = 0; + + ret = create_send_buffer(kr, &buf); + if (ret != EOK) { + DEBUG(1, ("create_send_buffer failed.\n")); + goto fail; + } + + ret = fork_child(kr); + if (ret != EOK) { + DEBUG(1, ("fork_child failed.\n")); + goto fail; + } + + subreq = write_pipe_send(state, ev, buf->data, buf->size, + kr->write_to_child_fd); + if (!subreq) { + ret = ENOMEM; + goto fail; + } + tevent_req_set_callback(subreq, handle_child_step, req); + + return req; + +fail: + tevent_req_error(req, ret); + tevent_req_post(req, ev); + return req; +} + +static void handle_child_step(struct tevent_req *subreq) +{ + struct tevent_req *req = tevent_req_callback_data(subreq, + struct tevent_req); + struct handle_child_state *state = tevent_req_data(req, + struct handle_child_state); + int ret; + + ret = write_pipe_recv(subreq); + talloc_zfree(subreq); + if (ret != EOK) { + tevent_req_error(req, ret); + return; + } + + close(state->kr->write_to_child_fd); + state->kr->write_to_child_fd = -1; + + subreq = read_pipe_send(state, state->ev, state->kr->read_from_child_fd); + if (!subreq) { + tevent_req_error(req, ENOMEM); + return; + } + tevent_req_set_callback(subreq, handle_child_done, req); +} + +static void handle_child_done(struct tevent_req *subreq) +{ + struct tevent_req *req = tevent_req_callback_data(subreq, + struct tevent_req); + struct handle_child_state *state = tevent_req_data(req, + struct handle_child_state); + int ret; + + ret = read_pipe_recv(subreq, state, &state->buf, &state->len); + talloc_zfree(subreq); + if (ret != EOK) { + tevent_req_error(req, ret); + return; + } + + close(state->kr->read_from_child_fd); + state->kr->read_from_child_fd = -1; + + tevent_req_done(req); + return; +} + +static int handle_child_recv(struct tevent_req *req, + TALLOC_CTX *mem_ctx, + uint8_t **buf, ssize_t *len) +{ + struct handle_child_state *state = tevent_req_data(req, + struct handle_child_state); + + TEVENT_REQ_RETURN_ON_ERROR(req); + + *buf = talloc_move(mem_ctx, &state->buf); + *len = state->len; + + return EOK; +} + +static void get_user_attr_done(void *pvt, int err, struct ldb_result *res); +static void krb5_resolve_done(struct tevent_req *req); +static void krb5_save_ccname_done(struct tevent_req *req); +static void krb5_child_done(struct tevent_req *req); +static void krb5_pam_handler_cache_done(struct tevent_req *treq); + +void krb5_pam_handler(struct be_req *be_req) +{ + struct pam_data *pd; + const char **attrs; + int pam_status = PAM_SYSTEM_ERR; + int dp_err = DP_ERR_FATAL; + int ret; + + pd = talloc_get_type(be_req->req_data, struct pam_data); + + switch (pd->cmd) { + case SSS_PAM_AUTHENTICATE: + case SSS_PAM_CHAUTHTOK: + case SSS_PAM_CHAUTHTOK_PRELIM: + break; + case SSS_PAM_ACCT_MGMT: + case SSS_PAM_SETCRED: + case SSS_PAM_OPEN_SESSION: + case SSS_PAM_CLOSE_SESSION: + pam_status = PAM_SUCCESS; + dp_err = DP_ERR_OK; + goto done; + break; + default: + DEBUG(4, ("krb5 does not handles pam task %d.\n", pd->cmd)); + pam_status = PAM_MODULE_UNKNOWN; + dp_err = DP_ERR_OK; + goto done; + } + + if (be_is_offline(be_req->be_ctx) && + (pd->cmd == SSS_PAM_CHAUTHTOK || pd->cmd == SSS_PAM_CHAUTHTOK_PRELIM)) { + DEBUG(9, ("Password changes are not possible while offline.\n")); + pam_status = PAM_AUTHINFO_UNAVAIL; + dp_err = DP_ERR_OFFLINE; + goto done; + } + + attrs = talloc_array(be_req, const char *, 4); + if (attrs == NULL) { + goto done; + } + + attrs[0] = SYSDB_UPN; + attrs[1] = SYSDB_HOMEDIR; + attrs[2] = SYSDB_CCACHE_FILE; + attrs[3] = NULL; + + ret = sysdb_get_user_attr(be_req, be_req->be_ctx->sysdb, + be_req->be_ctx->domain, pd->user, attrs, + get_user_attr_done, be_req); + + if (ret) { + goto done; + } + + return; + +done: + pd->pam_status = pam_status; + + krb_reply(be_req, dp_err, pd->pam_status); +} + +static void get_user_attr_done(void *pvt, int err, struct ldb_result *res) +{ + struct be_req *be_req = talloc_get_type(pvt, struct be_req); + struct krb5_ctx *krb5_ctx; + struct krb5child_req *kr = NULL; + struct tevent_req *req; + krb5_error_code kerr; + int ret; + struct pam_data *pd = talloc_get_type(be_req->req_data, struct pam_data); + int pam_status=PAM_SYSTEM_ERR; + int dp_err = DP_ERR_FATAL; + const char *ccache_file = NULL; + const char *realm; + + ret = krb5_setup(be_req, &kr); + if (ret != EOK) { + DEBUG(1, ("krb5_setup failed.\n")); + goto failed; + } + + krb5_ctx = kr->krb5_ctx; + + if (err != LDB_SUCCESS) { + DEBUG(5, ("sysdb search for upn of user [%s] failed.\n", pd->user)); + goto failed; + } + + realm = dp_opt_get_cstring(krb5_ctx->opts, KRB5_REALM); + if (realm == NULL) { + DEBUG(1, ("Missing Kerberos realm.\n")); + goto failed; + } + + switch (res->count) { + case 0: + DEBUG(5, ("No attributes for user [%s] found.\n", pd->user)); + goto failed; + break; + + case 1: + pd->upn = ldb_msg_find_attr_as_string(res->msgs[0], SYSDB_UPN, NULL); + if (pd->upn == NULL) { + /* NOTE: this is a hack, works only in some environments */ + pd->upn = talloc_asprintf(be_req, "%s@%s", pd->user, realm); + if (pd->upn == NULL) { + DEBUG(1, ("failed to build simple upn.\n")); + goto failed; + } + DEBUG(9, ("Using simple UPN [%s].\n", pd->upn)); + } + + kr->homedir = ldb_msg_find_attr_as_string(res->msgs[0], SYSDB_HOMEDIR, + NULL); + if (kr->homedir == NULL) { + DEBUG(4, ("Home directory for user [%s] not known.\n", pd->user)); + } + + ccache_file = ldb_msg_find_attr_as_string(res->msgs[0], + SYSDB_CCACHE_FILE, + NULL); + if (ccache_file != NULL) { + ret = check_if_ccache_file_is_used(pd->pw_uid, ccache_file, + &kr->active_ccache_present); + if (ret != EOK) { + DEBUG(1, ("check_if_ccache_file_is_used failed.\n")); + goto failed; + } + + kerr = check_for_valid_tgt(ccache_file, realm, pd->upn, + &kr->valid_tgt_present); + if (kerr != 0) { + DEBUG(1, ("check_for_valid_tgt failed.\n")); + goto failed; + } + } else { + kr->active_ccache_present = false; + kr->valid_tgt_present = false; + DEBUG(4, ("No ccache file for user [%s] found.\n", pd->user)); + } + DEBUG(9, ("Ccache_file is [%s] and is %s active and TGT is %s valid.\n", + ccache_file ? ccache_file : "not set", + kr->active_ccache_present ? "" : "not", + kr->valid_tgt_present ? "" : "not")); + kr->ccname = ccache_file; + break; + + default: + DEBUG(1, ("A user search by name (%s) returned > 1 results!\n", + pd->user)); + goto failed; + break; + } + + req = be_resolve_server_send(kr, be_req->be_ctx->ev, be_req->be_ctx, + krb5_ctx->service->name); + if (req == NULL) { + DEBUG(1, ("handle_child_send failed.\n")); + goto failed; + } + + tevent_req_set_callback(req, krb5_resolve_done, kr); + + return; + +failed: + talloc_free(kr); + + pd->pam_status = pam_status; + krb_reply(be_req, dp_err, pd->pam_status); +} + +static void krb5_resolve_done(struct tevent_req *req) +{ + struct krb5child_req *kr = tevent_req_callback_data(req, + struct krb5child_req); + int ret; + int pam_status = PAM_SYSTEM_ERR; + int dp_err = DP_ERR_FATAL; + struct pam_data *pd = kr->pd; + struct be_req *be_req = kr->req; + char *msg; + size_t offset = 0; + + ret = be_resolve_server_recv(req, &kr->srv); + talloc_zfree(req); + if (ret) { + /* all servers have been tried and none + * was found good, setting offline, + * but we still have to call the child to setup + * the ccache file. */ + be_mark_offline(be_req->be_ctx); + kr->is_offline = true; + } + + if (kr->ccname == NULL || + (be_is_offline(be_req->be_ctx) && !kr->active_ccache_present && + !kr->valid_tgt_present) || + (!be_is_offline(be_req->be_ctx) && !kr->active_ccache_present)) { + DEBUG(9, ("Recreating ccache file.\n")); + if (kr->ccname != NULL) { + if (strncmp(kr->ccname, "FILE:", 5) == 0) { + offset = 5; + } + if (kr->ccname[offset] != '/') { + DEBUG(1, ("Ccache file name [%s] is not an absolute path.\n", + kr->ccname + offset)); + goto done; + } + ret = unlink(kr->ccname + offset); + if (ret == -1 && errno != ENOENT) { + DEBUG(1, ("unlink [%s] failed [%d][%s].\n", kr->ccname, + errno, strerror(errno))); + goto done; + } + } + kr->ccname = expand_ccname_template(kr, kr, + dp_opt_get_cstring(kr->krb5_ctx->opts, + KRB5_CCNAME_TMPL) + ); + if (kr->ccname == NULL) { + DEBUG(1, ("expand_ccname_template failed.\n")); + goto done; + } + } + + if (be_is_offline(be_req->be_ctx)) { + DEBUG(9, ("Preparing for offline operation.\n")); + kr->is_offline = true; + + if (kr->valid_tgt_present) { + DEBUG(9, ("Valid TGT available, nothing to do.\n")); + msg = talloc_asprintf(pd, "%s=%s", CCACHE_ENV_NAME, kr->ccname); + if (msg == NULL) { + DEBUG(1, ("talloc_asprintf failed.\n")); + goto done; + } + + ret = pam_add_response(pd, SSS_PAM_ENV_ITEM, strlen(msg) + 1, + (uint8_t *) msg); + if (ret != EOK) { + DEBUG(1, ("pam_add_response failed.\n")); + } + + pam_status = PAM_AUTHINFO_UNAVAIL; + dp_err = DP_ERR_OFFLINE; + goto done; + } + memset(pd->authtok, 0, pd->authtok_size); + pd->authtok_size = 0; + + if (kr->active_ccache_present) { + req = krb5_save_ccname_send(kr, be_req->be_ctx->ev, + be_req->be_ctx->sysdb, + be_req->be_ctx->domain, pd->user, + kr->ccname); + if (req == NULL) { + DEBUG(1, ("krb5_save_ccname_send failed.\n")); + goto done; + } + + tevent_req_set_callback(req, krb5_save_ccname_done, kr); + return; + } + } + + req = handle_child_send(kr, be_req->be_ctx->ev, kr); + if (req == NULL) { + DEBUG(1, ("handle_child_send failed.\n")); + goto done; + } + + tevent_req_set_callback(req, krb5_child_done, kr); + return; + +done: + talloc_free(kr); + pd->pam_status = pam_status; + krb_reply(be_req, dp_err, pd->pam_status); +} + +static void krb5_child_done(struct tevent_req *req) +{ + struct krb5child_req *kr = tevent_req_callback_data(req, + struct krb5child_req); + struct pam_data *pd = kr->pd; + struct be_req *be_req = kr->req; + int ret; + uint8_t *buf = NULL; + ssize_t len = -1; + ssize_t pref_len; + int p; + int32_t *msg_status; + int32_t *msg_type; + int32_t *msg_len; + int pam_status = PAM_SYSTEM_ERR; + int dp_err = DP_ERR_FATAL; + + ret = handle_child_recv(req, pd, &buf, &len); + talloc_zfree(kr->timeout_handler); + talloc_zfree(req); + if (ret != EOK) { + DEBUG(1, ("child failed (%d [%s])\n", ret, strerror(ret))); + goto done; + } + + if ((size_t) len < 3*sizeof(int32_t)) { + DEBUG(1, ("message too short.\n")); + goto done; + } + + p=0; + msg_status = ((int32_t *)(buf+p)); + p += sizeof(int32_t); + + msg_type = ((int32_t *)(buf+p)); + p += sizeof(int32_t); + + msg_len = ((int32_t *)(buf+p)); + p += sizeof(int32_t); + + DEBUG(4, ("child response [%d][%d][%d].\n", *msg_status, *msg_type, + *msg_len)); + + if ((p + *msg_len) != len) { + DEBUG(1, ("message format error.\n")); + goto done; + } + + if (*msg_status != PAM_SUCCESS && *msg_status != PAM_AUTHINFO_UNAVAIL) { + pam_status = *msg_status; + dp_err = DP_ERR_OK; + + ret = pam_add_response(pd, *msg_type, *msg_len, &buf[p]); + if (ret != EOK) { + DEBUG(1, ("pam_add_response failed.\n")); + } + + goto done; + } else { + pd->pam_status = *msg_status; + } + + if (*msg_status == PAM_SUCCESS && pd->cmd == SSS_PAM_CHAUTHTOK_PRELIM) { + pam_status = PAM_SUCCESS; + dp_err = DP_ERR_OK; + goto done; + } + + pref_len = strlen(CCACHE_ENV_NAME)+1; + if (*msg_len > pref_len && + strncmp((const char *) &buf[p], CCACHE_ENV_NAME"=", pref_len) == 0) { + kr->ccname = talloc_strndup(kr, (char *) &buf[p+pref_len], + *msg_len-pref_len); + if (kr->ccname == NULL) { + DEBUG(1, ("talloc_strndup failed.\n")); + goto done; + } + } else { + DEBUG(1, ("Missing ccache name in child response [%.*s].\n", *msg_len, + &buf[p])); + goto done; + } + + if (*msg_status == PAM_AUTHINFO_UNAVAIL) { + if (kr->srv != NULL) { + fo_set_port_status(kr->srv, PORT_NOT_WORKING); + } + be_mark_offline(be_req->be_ctx); + kr->is_offline = true; + } else if (kr->srv != NULL) { + fo_set_port_status(kr->srv, PORT_WORKING); + } + + struct sysdb_attrs *attrs; + attrs = sysdb_new_attrs(kr); + ret = sysdb_attrs_add_string(attrs, SYSDB_CCACHE_FILE, kr->ccname); + if (ret != EOK) { + DEBUG(1, ("sysdb_attrs_add_string failed.\n")); + goto done; + } + + req = krb5_save_ccname_send(kr, be_req->be_ctx->ev, be_req->be_ctx->sysdb, + be_req->be_ctx->domain, pd->user, kr->ccname); + if (req == NULL) { + DEBUG(1, ("krb5_save_ccname_send failed.\n")); + goto done; + } + + tevent_req_set_callback(req, krb5_save_ccname_done, kr); + return; +done: + talloc_free(kr); + pd->pam_status = pam_status; + krb_reply(be_req, dp_err, pd->pam_status); +} + +static void krb5_save_ccname_done(struct tevent_req *req) +{ + struct krb5child_req *kr = tevent_req_callback_data(req, + struct krb5child_req); + struct pam_data *pd = kr->pd; + struct be_req *be_req = kr->req; + struct krb5_ctx *krb5_ctx = kr->krb5_ctx; + int pam_status = PAM_SYSTEM_ERR; + int dp_err = DP_ERR_FATAL; + int ret; + char *password = NULL; + + if (pd->cmd == SSS_PAM_AUTHENTICATE) { + ret = add_krb5_env(krb5_ctx->opts, kr->ccname, pd); + if (ret != EOK) { + DEBUG(1, ("add_krb5_env failed.\n")); + goto failed; + } + } + + ret = sysdb_set_user_attr_recv(req); + talloc_zfree(req); + if (ret != EOK) { + DEBUG(1, ("Saving ccache name failed.\n")); + goto failed; + } + + if (kr->is_offline) { + DEBUG(4, ("Backend is marked offline, retry later!\n")); + pam_status = PAM_AUTHINFO_UNAVAIL; + dp_err = DP_ERR_OFFLINE; + goto failed; + } + + if (be_req->be_ctx->domain->cache_credentials == TRUE) { + + /* password caching failures are not fatal errors */ + pd->pam_status = PAM_SUCCESS; + + switch(pd->cmd) { + case SSS_PAM_AUTHENTICATE: + case SSS_PAM_CHAUTHTOK_PRELIM: + password = talloc_size(be_req, pd->authtok_size + 1); + if (password != NULL) { + memcpy(password, pd->authtok, pd->authtok_size); + password[pd->authtok_size] = '\0'; + } + break; + case SSS_PAM_CHAUTHTOK: + password = talloc_size(be_req, pd->newauthtok_size + 1); + if (password != NULL) { + memcpy(password, pd->newauthtok, pd->newauthtok_size); + password[pd->newauthtok_size] = '\0'; + } + break; + default: + DEBUG(0, ("unsupported PAM command [%d].\n", pd->cmd)); + } + + if (password == NULL) { + DEBUG(0, ("password not available, offline auth may not work.\n")); + goto failed; + } + + talloc_set_destructor((TALLOC_CTX *)password, password_destructor); + + req = sysdb_cache_password_send(be_req, be_req->be_ctx->ev, + be_req->be_ctx->sysdb, NULL, + be_req->be_ctx->domain, pd->user, + password); + if (req == NULL) { + DEBUG(2, ("cache_password_send failed, offline auth may not work.\n")); + goto failed; + } + tevent_req_set_callback(req, krb5_pam_handler_cache_done, be_req); + return; + } + + pam_status = PAM_SUCCESS; + dp_err = DP_ERR_OK; + +failed: + talloc_free(kr); + + pd->pam_status = pam_status; + krb_reply(be_req, dp_err, pd->pam_status); +} + +static void krb5_pam_handler_cache_done(struct tevent_req *subreq) +{ + struct be_req *be_req = tevent_req_callback_data(subreq, struct be_req); + int ret; + + /* password caching failures are not fatal errors */ + ret = sysdb_cache_password_recv(subreq); + talloc_zfree(subreq); + + /* so we just log it any return */ + if (ret) { + DEBUG(2, ("Failed to cache password (%d)[%s]!?\n", + ret, strerror(ret))); + } + + krb_reply(be_req, DP_ERR_OK, PAM_SUCCESS); +} + +static void krb_reply(struct be_req *req, int dp_err, int result) +{ + req->fn(req, dp_err, result, NULL); +} + |