/* SSSD PAM Responder Copyright (C) Simo Sorce 2009 Copyright (C) Sumit Bose 2009 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 . */ #include #include "util/util.h" #include "db/sysdb.h" #include "confdb/confdb.h" #include "responder/common/responder_packet.h" #include "responder/common/responder.h" #include "providers/data_provider.h" #include "responder/pam/pamsrv.h" #include "db/sysdb.h" static int extract_authtok(uint32_t *type, uint32_t *size, uint8_t **tok, uint8_t *body, size_t blen, size_t *c) { size_t data_size; if (blen-(*c) < 2*sizeof(uint32_t)) return EINVAL; data_size = ((uint32_t *)&body[*c])[0]; *c += sizeof(uint32_t); if (data_size < sizeof(uint32_t) || (*c)+(data_size) > blen) return EINVAL; *size = data_size - sizeof(uint32_t); *type = ((uint32_t *)&body[*c])[0]; *c += sizeof(uint32_t); *tok = body+(*c); *c += (*size); return EOK; } static int extract_string(char **var, uint8_t *body, size_t blen, size_t *c) { uint32_t size; uint8_t *str; if (blen-(*c) < sizeof(uint32_t)+1) return EINVAL; size = ((uint32_t *)&body[*c])[0]; *c += sizeof(uint32_t); if (*c+size > blen) return EINVAL; str = body+(*c); if (str[size-1]!='\0') return EINVAL; *c += size; *var = (char *) str; return EOK; } static int pam_parse_in_data_v2(struct sss_names_ctx *snctx, struct pam_data *pd, uint8_t *body, size_t blen) { size_t c; uint32_t type; uint32_t size; char *pam_user; int ret; if (blen < 4*sizeof(uint32_t)+2 || ((uint32_t *)body)[0] != START_OF_PAM_REQUEST || ((uint32_t *)(&body[blen - sizeof(uint32_t)]))[0] != END_OF_PAM_REQUEST) { DEBUG(1, ("Received data is invalid.\n")); return EINVAL; } c = sizeof(uint32_t); do { type = ((uint32_t *)&body[c])[0]; c += sizeof(uint32_t); if (c > blen) return EINVAL; switch(type) { case PAM_ITEM_USER: ret = extract_string(&pam_user, body, blen, &c); if (ret != EOK) return ret; ret = sss_parse_name(pd, snctx, pam_user, &pd->domain, &pd->user); if (ret != EOK) return ret; break; case PAM_ITEM_SERVICE: ret = extract_string(&pd->service, body, blen, &c); if (ret != EOK) return ret; break; case PAM_ITEM_TTY: ret = extract_string(&pd->tty, body, blen, &c); if (ret != EOK) return ret; break; case PAM_ITEM_RUSER: ret = extract_string(&pd->ruser, body, blen, &c); if (ret != EOK) return ret; break; case PAM_ITEM_RHOST: ret = extract_string(&pd->rhost, body, blen, &c); if (ret != EOK) return ret; break; case PAM_ITEM_AUTHTOK: ret = extract_authtok(&pd->authtok_type, &pd->authtok_size, &pd->authtok, body, blen, &c); if (ret != EOK) return ret; break; case PAM_ITEM_NEWAUTHTOK: ret = extract_authtok(&pd->newauthtok_type, &pd->newauthtok_size, &pd->newauthtok, body, blen, &c); if (ret != EOK) return ret; break; case END_OF_PAM_REQUEST: if (c != blen) return EINVAL; break; default: DEBUG(1,("Ignoring unknown data type [%d].\n", type)); size = ((uint32_t *)&body[c])[0]; c += size+sizeof(uint32_t); } } while(c < blen); if (pd->user == NULL || *pd->user == '\0') return EINVAL; DEBUG_PAM_DATA(4, pd); return EOK; } static int pam_parse_in_data(struct sss_names_ctx *snctx, struct pam_data *pd, uint8_t *body, size_t blen) { int start; int end; int last; int ret; last = blen - 1; end = 0; /* user name */ for (start = end; end < last; end++) if (body[end] == '\0') break; if (body[end++] != '\0') return EINVAL; ret = sss_parse_name(pd, snctx, (char *)&body[start], &pd->domain, &pd->user); if (ret != EOK) return ret; for (start = end; end < last; end++) if (body[end] == '\0') break; if (body[end++] != '\0') return EINVAL; pd->service = (char *) &body[start]; for (start = end; end < last; end++) if (body[end] == '\0') break; if (body[end++] != '\0') return EINVAL; pd->tty = (char *) &body[start]; for (start = end; end < last; end++) if (body[end] == '\0') break; if (body[end++] != '\0') return EINVAL; pd->ruser = (char *) &body[start]; for (start = end; end < last; end++) if (body[end] == '\0') break; if (body[end++] != '\0') return EINVAL; pd->rhost = (char *) &body[start]; start = end; pd->authtok_type = (int) body[start]; start += sizeof(uint32_t); pd->authtok_size = (int) body[start]; start += sizeof(uint32_t); end = start + pd->authtok_size; if (pd->authtok_size == 0) { pd->authtok = NULL; } else { if (end <= blen) { pd->authtok = (uint8_t *) &body[start]; } else { DEBUG(1, ("Invalid authtok size: %d\n", pd->authtok_size)); return EINVAL; } } start = end; pd->newauthtok_type = (int) body[start]; start += sizeof(uint32_t); pd->newauthtok_size = (int) body[start]; start += sizeof(uint32_t); end = start + pd->newauthtok_size; if (pd->newauthtok_size == 0) { pd->newauthtok = NULL; } else { if (end <= blen) { pd->newauthtok = (uint8_t *) &body[start]; } else { DEBUG(1, ("Invalid newauthtok size: %d\n", pd->newauthtok_size)); return EINVAL; } } DEBUG_PAM_DATA(4, pd); return EOK; } static void pam_reply(struct pam_auth_req *preq); static void pam_reply_delay(struct tevent_context *ev, struct tevent_timer *te, struct timeval tv, void *pvt) { struct pam_auth_req *preq; DEBUG(4, ("pam_reply_delay get called.\n")); preq = talloc_get_type(pvt, struct pam_auth_req); pam_reply(preq); } static void pam_reply(struct pam_auth_req *preq) { struct cli_ctx *cctx; uint8_t *body; size_t blen; int ret; int err = EOK; int32_t resp_c; int32_t resp_size; struct response_data *resp; int p; struct timeval tv; struct tevent_timer *te; struct pam_data *pd; pd = preq->pd; DEBUG(4, ("pam_reply get called.\n")); if ((pd->cmd == SSS_PAM_AUTHENTICATE) && (preq->domain != NULL) && (preq->domain->cache_credentials == true) && (pd->offline_auth == false)) { if (pd->pam_status == PAM_AUTHINFO_UNAVAIL) { /* do auth with offline credentials */ pd->offline_auth = true; preq->callback = pam_reply; ret = pam_cache_auth(preq); if (ret == EOK) { return; } else { DEBUG(1, ("Failed to setup offline auth")); /* this error is not fatal, continue */ } } } /* TODO: we need the pam session cookie here to make sure that cached * authentication was successful */ if ((pd->cmd == SSS_PAM_SETCRED || pd->cmd == SSS_PAM_ACCT_MGMT || pd->cmd == SSS_PAM_OPEN_SESSION || pd->cmd == SSS_PAM_CLOSE_SESSION) && pd->pam_status == PAM_AUTHINFO_UNAVAIL) { DEBUG(2, ("Assuming offline authentication " "setting status for pam call %d to PAM_SUCCESS.\n", pd->cmd)); pd->pam_status = PAM_SUCCESS; } cctx = preq->cctx; if (pd->response_delay > 0) { ret = gettimeofday(&tv, NULL); if (ret != EOK) { DEBUG(1, ("gettimeofday failed [%d][%s].\n", errno, strerror(errno))); err = ret; goto done; } tv.tv_sec += pd->response_delay; tv.tv_usec = 0; pd->response_delay = 0; te = tevent_add_timer(cctx->ev, cctx, tv, pam_reply_delay, preq); if (te == NULL) { DEBUG(1, ("Failed to add event pam_reply_delay.\n")); err = ENOMEM; goto done; } return; } ret = sss_packet_new(cctx->creq, 0, sss_packet_get_cmd(cctx->creq->in), &cctx->creq->out); if (ret != EOK) { err = ret; goto done; } if (pd->domain != NULL) { pam_add_response(pd, PAM_DOMAIN_NAME, strlen(pd->domain)+1, (uint8_t *) pd->domain); } resp_c = 0; resp_size = 0; resp = pd->resp_list; while(resp != NULL) { resp_c++; resp_size += resp->len; resp = resp->next; } ret = sss_packet_grow(cctx->creq->out, sizeof(int32_t) + sizeof(int32_t) + resp_c * 2* sizeof(int32_t) + resp_size); if (ret != EOK) { err = ret; goto done; } sss_packet_get_body(cctx->creq->out, &body, &blen); DEBUG(4, ("blen: %d\n", blen)); p = 0; memcpy(&body[p], &pd->pam_status, sizeof(int32_t)); p += sizeof(int32_t); memcpy(&body[p], &resp_c, sizeof(int32_t)); p += sizeof(int32_t); resp = pd->resp_list; while(resp != NULL) { memcpy(&body[p], &resp->type, sizeof(int32_t)); p += sizeof(int32_t); memcpy(&body[p], &resp->len, sizeof(int32_t)); p += sizeof(int32_t); memcpy(&body[p], resp->data, resp->len); p += resp->len; resp = resp->next; } done: sss_cmd_done(cctx, preq); } static void pam_check_user_dp_callback(uint16_t err_maj, uint32_t err_min, const char *err_msg, void *ptr); static void pam_check_user_callback(void *ptr, int status, struct ldb_result *res); static void pam_dom_forwarder(struct pam_auth_req *preq); /* TODO: we should probably return some sort of cookie that is set in the * PAM_ENVIRONMENT, so that we can save performing some calls and cache * data. */ static int pam_forwarder(struct cli_ctx *cctx, int pam_cmd) { struct sss_domain_info *dom; struct pam_auth_req *preq; struct pam_data *pd; uint8_t *body; size_t blen; int timeout; int ret; preq = talloc_zero(cctx, struct pam_auth_req); if (!preq) { return ENOMEM; } preq->cctx = cctx; preq->pd = talloc_zero(preq, struct pam_data); if (!preq->pd) { talloc_free(preq); return ENOMEM; } pd = preq->pd; sss_packet_get_body(cctx->creq->in, &body, &blen); if (blen >= sizeof(uint32_t) && ((uint32_t *)(&body[blen - sizeof(uint32_t)]))[0] != END_OF_PAM_REQUEST) { DEBUG(1, ("Received data not terminated.\n")); talloc_free(preq); ret = EINVAL; goto done; } pd->cmd = pam_cmd; pd->priv = cctx->priv; switch (cctx->cli_protocol_version->version) { case 1: ret = pam_parse_in_data(cctx->rctx->names, pd, body, blen); break; case 2: ret = pam_parse_in_data_v2(cctx->rctx->names, pd, body, blen); break; default: DEBUG(1, ("Illegal protocol version [%d].\n", cctx->cli_protocol_version->version)); ret = EINVAL; } if (ret != EOK) { talloc_free(preq); ret = EINVAL; goto done; } /* now check user is valid */ if (pd->domain) { for (dom = cctx->rctx->domains; dom; dom = dom->next) { if (strcasecmp(dom->name, pd->domain) == 0) break; } if (!dom) { talloc_free(preq); ret = ENOENT; goto done; } preq->domain = dom; } else { for (dom = preq->cctx->rctx->domains; dom; dom = dom->next) { if (dom->fqnames) continue; /* FIXME: need to support negative cache */ #if HAVE_NEG_CACHE ncret = sss_ncache_check_user(nctx->ncache, nctx->neg_timeout, dom->name, cmdctx->name); if (ncret == ENOENT) break; #endif break; } if (!dom) { ret = ENOENT; goto done; } preq->domain = dom; } if (preq->domain->provider == NULL) { DEBUG(1, ("Domain [%s] has no auth provider.\n", preq->domain->name)); ret = EINVAL; goto done; } /* When auth is requested always search the provider first, * do not rely on cached data unless the provider is completely * offline */ if (NEED_CHECK_PROVIDER(preq->domain->provider) && (pam_cmd == SSS_PAM_AUTHENTICATE || pam_cmd == SSS_PAM_SETCRED)) { /* no need to re-check later on */ preq->check_provider = false; timeout = SSS_CLI_SOCKET_TIMEOUT/2; ret = nss_dp_send_acct_req(preq->cctx->rctx, preq, pam_check_user_dp_callback, preq, timeout, preq->domain->name, NSS_DP_USER, preq->pd->user, 0); } else { preq->check_provider = NEED_CHECK_PROVIDER(preq->domain->provider); ret = sysdb_getpwnam(preq, cctx->rctx->sysdb, preq->domain, preq->pd->user, pam_check_user_callback, preq); } done: if (ret != EOK) { switch (ret) { case ENOENT: pd->pam_status = PAM_USER_UNKNOWN; default: pd->pam_status = PAM_SYSTEM_ERR; } pam_reply(preq); } return EOK; } static void pam_check_user_dp_callback(uint16_t err_maj, uint32_t err_min, const char *err_msg, void *ptr) { struct pam_auth_req *preq = talloc_get_type(ptr, struct pam_auth_req); struct ldb_result *res = NULL; int ret; if ((err_maj != DP_ERR_OK) && (err_maj != DP_ERR_OFFLINE)) { DEBUG(2, ("Unable to get information from Data Provider\n" "Error: %u, %u, %s\n", (unsigned int)err_maj, (unsigned int)err_min, err_msg)); ret = EFAULT; goto done; } if (err_maj == DP_ERR_OFFLINE) { if (preq->data) res = talloc_get_type(preq->data, struct ldb_result); if (!res) res = talloc_zero(preq, struct ldb_result); if (!res) { ret = EFAULT; goto done; } pam_check_user_callback(preq, LDB_SUCCESS, res); return; } ret = sysdb_getpwnam(preq, preq->cctx->rctx->sysdb, preq->domain, preq->pd->user, pam_check_user_callback, preq); done: if (ret != EOK) { preq->pd->pam_status = PAM_SYSTEM_ERR; pam_reply(preq); } } static void pam_check_user_callback(void *ptr, int status, struct ldb_result *res) { struct pam_auth_req *preq = talloc_get_type(ptr, struct pam_auth_req); struct sss_domain_info *dom; uint64_t lastUpdate; bool call_provider = false; time_t timeout; time_t cache_timeout; int ret; if (status != LDB_SUCCESS) { preq->pd->pam_status = PAM_SYSTEM_ERR; pam_reply(preq); return; } timeout = SSS_CLI_SOCKET_TIMEOUT/2; if (preq->check_provider) { switch (res->count) { case 0: call_provider = true; break; case 1: cache_timeout = 30; /* FIXME: read from conf */ lastUpdate = ldb_msg_find_attr_as_uint64(res->msgs[0], SYSDB_LAST_UPDATE, 0); if (lastUpdate + cache_timeout < time(NULL)) { call_provider = true; } break; default: DEBUG(1, ("check user call returned more than one result !?!\n")); preq->pd->pam_status = PAM_SYSTEM_ERR; pam_reply(preq); return; } } if (call_provider) { /* dont loop forever :-) */ preq->check_provider = false; /* keep around current data in case backend is offline */ if (res->count) { preq->data = talloc_steal(preq, res); } ret = nss_dp_send_acct_req(preq->cctx->rctx, preq, pam_check_user_dp_callback, preq, timeout, preq->domain->name, NSS_DP_USER, preq->pd->user, 0); if (ret != EOK) { DEBUG(3, ("Failed to dispatch request: %d(%s)\n", ret, strerror(ret))); preq->pd->pam_status = PAM_SYSTEM_ERR; pam_reply(preq); } return; } switch (res->count) { case 0: if (!preq->pd->domain) { /* search next as the domain was unknown */ ret = EOK; /* skip domains that require FQnames or have negative caches */ for (dom = preq->domain->next; dom; dom = dom->next) { if (dom->fqnames) continue; #if HAVE_NEG_CACHE ncret = nss_ncache_check_user(nctx->ncache, nctx->neg_timeout, dom->name, cmdctx->name); if (ncret == ENOENT) break; neghit = true; #endif break; } #if HAVE_NEG_CACHE /* reset neghit if we still have a domain to check */ if (dom) neghit = false; if (neghit) { DEBUG(2, ("User [%s] does not exist! (negative cache)\n", cmdctx->name)); ret = ENOENT; } #endif if (dom == NULL) { DEBUG(2, ("No matching domain found for [%s], fail!\n", preq->pd->user)); ret = ENOENT; } if (ret == EOK) { preq->domain = dom; preq->data = NULL; DEBUG(4, ("Requesting info for [%s@%s]\n", preq->pd->user, preq->domain->name)); /* When auth is requested always search the provider first, * do not rely on cached data unless the provider is * completely offline */ if (NEED_CHECK_PROVIDER(preq->domain->provider) && (preq->pd->cmd == SSS_PAM_AUTHENTICATE || preq->pd->cmd == SSS_PAM_SETCRED)) { /* no need to re-check later on */ preq->check_provider = false; ret = nss_dp_send_acct_req(preq->cctx->rctx, preq, pam_check_user_dp_callback, preq, timeout, preq->domain->name, NSS_DP_USER, preq->pd->user, 0); } else { preq->check_provider = NEED_CHECK_PROVIDER(preq->domain->provider); ret = sysdb_getpwnam(preq, preq->cctx->rctx->sysdb, preq->domain, preq->pd->user, pam_check_user_callback, preq); } if (ret != EOK) { DEBUG(1, ("Failed to make request to our cache!\n")); } } /* we made another call, end here */ if (ret == EOK) return; } else { ret = ENOENT; } DEBUG(2, ("No results for check user call\n")); #if HAVE_NEG_CACHE /* set negative cache only if not result of cache check */ if (!neghit) { ret = nss_ncache_set_user(nctx->ncache, false, dctx->domain->name, cmdctx->name); if (ret != EOK) { NSS_CMD_FATAL_ERROR(cctx); } } #endif if (ret != EOK) { if (ret == ENOENT) { preq->pd->pam_status = PAM_USER_UNKNOWN; } else { preq->pd->pam_status = PAM_SYSTEM_ERR; } pam_reply(preq); return; } break; case 1: /* BINGO */ preq->pd->pw_uid = ldb_msg_find_attr_as_int(res->msgs[0], SYSDB_UIDNUM, -1); if (preq->pd->pw_uid == -1) { DEBUG(1, ("Failed to find uid for user [%s] in domain [%s].\n", preq->pd->user, preq->pd->domain)); preq->pd->pam_status = PAM_SYSTEM_ERR; pam_reply(preq); } preq->pd->gr_gid = ldb_msg_find_attr_as_int(res->msgs[0], SYSDB_GIDNUM, -1); if (preq->pd->gr_gid == -1) { DEBUG(1, ("Failed to find gid for user [%s] in domain [%s].\n", preq->pd->user, preq->pd->domain)); preq->pd->pam_status = PAM_SYSTEM_ERR; pam_reply(preq); } pam_dom_forwarder(preq); return; default: DEBUG(1, ("check user call returned more than one result !?!\n")); preq->pd->pam_status = PAM_SYSTEM_ERR; pam_reply(preq); } } static void pam_dom_forwarder(struct pam_auth_req *preq) { int ret; if (!preq->pd->domain) { preq->pd->domain = preq->domain->name; } if (!NEED_CHECK_PROVIDER(preq->domain->provider)) { preq->callback = pam_reply; ret = LOCAL_pam_handler(preq); } else { preq->callback = pam_reply; ret = pam_dp_send_req(preq, SSS_CLI_SOCKET_TIMEOUT/2); DEBUG(4, ("pam_dp_send_req returned %d\n", ret)); } if (ret != EOK) { preq->pd->pam_status = PAM_SYSTEM_ERR; pam_reply(preq); } } static int pam_cmd_authenticate(struct cli_ctx *cctx) { DEBUG(4, ("entering pam_cmd_authenticate\n")); return pam_forwarder(cctx, SSS_PAM_AUTHENTICATE); } static int pam_cmd_setcred(struct cli_ctx *cctx) { DEBUG(4, ("entering pam_cmd_setcred\n")); return pam_forwarder(cctx, SSS_PAM_SETCRED); } static int pam_cmd_acct_mgmt(struct cli_ctx *cctx) { DEBUG(4, ("entering pam_cmd_acct_mgmt\n")); return pam_forwarder(cctx, SSS_PAM_ACCT_MGMT); } static int pam_cmd_open_session(struct cli_ctx *cctx) { DEBUG(4, ("entering pam_cmd_open_session\n")); return pam_forwarder(cctx, SSS_PAM_OPEN_SESSION); } static int pam_cmd_close_session(struct cli_ctx *cctx) { DEBUG(4, ("entering pam_cmd_close_session\n")); return pam_forwarder(cctx, SSS_PAM_CLOSE_SESSION); } static int pam_cmd_chauthtok(struct cli_ctx *cctx) { DEBUG(4, ("entering pam_cmd_chauthtok\n")); return pam_forwarder(cctx, SSS_PAM_CHAUTHTOK); } struct cli_protocol_version *register_cli_protocol_version(void) { static struct cli_protocol_version pam_cli_protocol_version[] = { {1, "2008-09-05", "initial version, \\0 terminated strings"}, {2, "2009-05-12", "new format "}, {0, NULL, NULL} }; return pam_cli_protocol_version; } struct sss_cmd_table *register_sss_cmds(void) { static struct sss_cmd_table sss_cmds[] = { {SSS_GET_VERSION, sss_cmd_get_version}, {SSS_PAM_AUTHENTICATE, pam_cmd_authenticate}, {SSS_PAM_SETCRED, pam_cmd_setcred}, {SSS_PAM_ACCT_MGMT, pam_cmd_acct_mgmt}, {SSS_PAM_OPEN_SESSION, pam_cmd_open_session}, {SSS_PAM_CLOSE_SESSION, pam_cmd_close_session}, {SSS_PAM_CHAUTHTOK, pam_cmd_chauthtok}, {SSS_CLI_NULL, NULL} }; return sss_cmds; }