From 9556ce77ae0c36cc63f5afb8bcf22637b8667517 Mon Sep 17 00:00:00 2001 From: Sumit Bose Date: Fri, 29 Oct 2010 14:46:21 +0200 Subject: [PATCH 6/6] Call krb5_child to check access permissions --- src/man/sssd-krb5.5.xml | 8 +++ src/providers/krb5/krb5_access.c | 125 ++++++++++++++++++++++++++++++++++++- 2 files changed, 129 insertions(+), 4 deletions(-) diff --git a/src/man/sssd-krb5.5.xml b/src/man/sssd-krb5.5.xml index e9c2cac..0238af1 100644 --- a/src/man/sssd-krb5.5.xml +++ b/src/man/sssd-krb5.5.xml @@ -44,6 +44,14 @@ configure this. + This backend also provides access control based on the .k5login + file in the home directory of the user. See + .k5login5 + for more details. Please note that an empty .k5login + file will deny all access to this user. To activate this feature + use 'access_provider = krb5' in your sssd configuration. + + In the case where the UPN is not available in the identity backend sssd will construct a UPN using the format username@krb5_realm. diff --git a/src/providers/krb5/krb5_access.c b/src/providers/krb5/krb5_access.c index 2154933..4becd03 100644 --- a/src/providers/krb5/krb5_access.c +++ b/src/providers/krb5/krb5_access.c @@ -24,6 +24,7 @@ #include "util/util.h" #include "providers/krb5/krb5_auth.h" +#include "providers/krb5/krb5_common.h" struct krb5_access_state { struct tevent_context *ev; @@ -31,11 +32,12 @@ struct krb5_access_state { struct pam_data *pd; struct krb5_ctx *krb5_ctx; - const char *upn; + struct krb5child_req *kr; bool access_allowed; }; +static void krb5_access_child_done(struct tevent_req *subreq); struct tevent_req *krb5_access_send(TALLOC_CTX *mem_ctx, struct tevent_context *ev, struct be_ctx *be_ctx, @@ -44,7 +46,10 @@ struct tevent_req *krb5_access_send(TALLOC_CTX *mem_ctx, { struct krb5_access_state *state; struct tevent_req *req; + struct tevent_req *subreq; int ret; + const char **attrs; + struct ldb_result *res; req = tevent_req_create(mem_ctx, &state, struct krb5_access_state); if (req == NULL) { @@ -56,17 +61,90 @@ struct tevent_req *krb5_access_send(TALLOC_CTX *mem_ctx, state->be_ctx = be_ctx; state->pd = pd; state->krb5_ctx = krb5_ctx; - state->upn = NULL; state->access_allowed = false; + ret = krb5_setup(state, pd, krb5_ctx, &state->kr); + if (ret != EOK) { + DEBUG(1, ("krb5_setup failed.\n")); + goto done; + } + if (pd->cmd != SSS_PAM_ACCT_MGMT) { DEBUG(1, ("Unexpected pam task.\n")); ret = EINVAL; goto done; } - state->access_allowed = true; - ret = EOK; + attrs = talloc_array(state, const char *, 4); + if (attrs == NULL) { + DEBUG(1, ("talloc_array failed.\n")); + ret = ENOMEM; + goto done; + } + + attrs[0] = SYSDB_UPN; + attrs[1] = SYSDB_UIDNUM; + attrs[2] = SYSDB_GIDNUM; + attrs[3] = NULL; + + ret = sysdb_get_user_attr(state, be_ctx->sysdb, be_ctx->domain, + state->pd->user, attrs, &res); + if (ret) { + DEBUG(5, ("sysdb search for upn of user [%s] failed.\n", pd->user)); + goto done; + } + + switch (res->count) { + case 0: + DEBUG(5, ("No attributes for user [%s] found.\n", pd->user)); + ret = ENOENT; + goto done; + break; + case 1: + state->kr->upn = ldb_msg_find_attr_as_string(res->msgs[0], SYSDB_UPN, + NULL); + if (state->kr->upn == NULL) { + ret = krb5_get_simple_upn(state, krb5_ctx, pd->user, + &state->kr->upn); + if (ret != EOK) { + DEBUG(1, ("krb5_get_simple_upn failed.\n")); + goto done; + } + } + + state->kr->uid = ldb_msg_find_attr_as_uint64(res->msgs[0], SYSDB_UIDNUM, + 0); + if (state->kr->uid == 0) { + DEBUG(4, ("UID for user [%s] not known.\n", pd->user)); + ret = ENOENT; + goto done; + } + + state->kr->gid = ldb_msg_find_attr_as_uint64(res->msgs[0], SYSDB_GIDNUM, + 0); + if (state->kr->gid == 0) { + DEBUG(4, ("GID for user [%s] not known.\n", pd->user)); + ret = ENOENT; + goto done; + } + + break; + default: + DEBUG(1, ("User search for [%s] returned > 1 results!\n", pd->user)); + ret = EINVAL; + goto done; + break; + } + + subreq = handle_child_send(state, state->ev, state->kr); + if (subreq == NULL) { + DEBUG(1, ("handle_child_send failed.\n")); + ret = ENOMEM; + goto done; + } + + tevent_req_set_callback(subreq, krb5_access_child_done, req); + return req; done: if (ret == EOK) { @@ -78,6 +156,45 @@ done: return req; } +static void krb5_access_child_done(struct tevent_req *subreq) +{ + struct tevent_req *req = tevent_req_callback_data(subreq, struct tevent_req); + struct krb5_access_state *state = tevent_req_data(req, + struct krb5_access_state); + int ret; + uint8_t *buf = NULL; + ssize_t len = -1; + int32_t msg_status; + + ret = handle_child_recv(subreq, state, &buf, &len); + talloc_free(subreq); + if (ret != EOK) { + DEBUG(1, ("child failed [%d][%s].\n", ret, strerror(ret))); + goto fail; + } + + if ((size_t) len != sizeof(int32_t)) { + DEBUG(1, ("message has the wrong size.\n")); + ret = EINVAL; + goto fail; + } + + SAFEALIGN_COPY_INT32(&msg_status, buf, NULL); + + if (msg_status == EOK) { + state->access_allowed = true; + } else { + state->access_allowed = false; + } + + tevent_req_done(req); + return; + +fail: + tevent_req_error(req, ret); + return; +} + int krb5_access_recv(struct tevent_req *req, bool *access_allowed) { struct krb5_access_state *state = tevent_req_data(req, -- 1.7.2.3