Refactor the way subdomain accounts are saved

The original sysdb code had a strong assumption that only users from one
domain are saved in the databse, with the subdomain feature, we have
changed reality, but have not adjusted all the code arund the sysdb calls
to not rely on the original assumption.

One of the side effects of this incongrunece is that currently group
memberships do not return fully qualified names for subdomain users as they
should.

In oreder to fix this and other potential issues surrounding the violation
of the original assumption, we need to fully qualify subdomain user names.
By savin them fully qualified we do not risk aliasing local users and have
group memberhips or other name based matching code mistake a domain user
with subdomain usr or vice versa.

10 files changed, 167 insertions, 35 deletions

diff --git a/src/db/sysdb.h b/src/db/sysdb.h
index c701717f9..6bfe30664 100644
--- a/src/db/sysdb.h
+++ b/src/db/sysdb.h
@@ -437,6 +437,15 @@ errno_t sysdb_store_domgroup(struct sss_domain_info *domain,
 errno_t sysdb_delete_domgroup(struct sss_domain_info *domain,
                               const char *name, gid_t gid);
 
+int sysdb_subdom_getpwnam(TALLOC_CTX *mem_ctx,
+                          struct sysdb_ctx *sysdb,
+                          const char *name,
+                          struct ldb_result **res);
+int sysdb_subdom_getgrnam(TALLOC_CTX *mem_ctx,
+                          struct sysdb_ctx *sysdb,
+                          const char *name,
+                          struct ldb_result **res);
+
 errno_t sysdb_get_ranges(TALLOC_CTX *mem_ctx, struct sysdb_ctx *sysdb,
                              size_t *range_count,
                              struct range_info ***range_list);
diff --git a/src/db/sysdb_search.c b/src/db/sysdb_search.c
index 1ab947700..49f628bfd 100644
--- a/src/db/sysdb_search.c
+++ b/src/db/sysdb_search.c
@@ -365,7 +365,9 @@ int sysdb_initgroups(TALLOC_CTX *mem_ctx,
         return ENOMEM;
     }
 
-    ret = sysdb_getpwnam(tmp_ctx, sysdb, name, &res);
+    /* if this is a subdomain we need to search for the fully qualified
+     * name in the database */
+    ret = sysdb_subdom_getpwnam(tmp_ctx, sysdb, name, &res);
     if (ret != EOK) {
         DEBUG(1, ("sysdb_getpwnam failed: [%d][%s]\n",
                   ret, strerror(ret)));
diff --git a/src/db/sysdb_subdomains.c b/src/db/sysdb_subdomains.c
index 2e0170f4d..231d481ca 100644
--- a/src/db/sysdb_subdomains.c
+++ b/src/db/sysdb_subdomains.c
@@ -668,3 +668,43 @@ errno_t sysdb_delete_domgroup(struct sss_domain_info *domain,
 
     return sysdb_delete_group(domain->sysdb, name, gid);
 }
+
+int sysdb_subdom_getpwnam(TALLOC_CTX *mem_ctx,
+                          struct sysdb_ctx *sysdb,
+                          const char *name,
+                          struct ldb_result **res)
+{
+    char *src_name = NULL;
+    int ret;
+
+    if (sysdb->domain->parent) {
+        src_name = talloc_asprintf(mem_ctx, sysdb->domain->names->fq_fmt,
+                                   name, sysdb->domain->name);
+        if (!src_name) return ENOMEM;
+    }
+
+    ret = sysdb_getpwnam(mem_ctx, sysdb, src_name ? src_name : name, res);
+    talloc_zfree(src_name);
+
+    return ret;
+}
+
+int sysdb_subdom_getgrnam(TALLOC_CTX *mem_ctx,
+                          struct sysdb_ctx *sysdb,
+                          const char *name,
+                          struct ldb_result **res)
+{
+    char *src_name = NULL;
+    int ret;
+
+    if (sysdb->domain->parent) {
+        src_name = talloc_asprintf(mem_ctx, sysdb->domain->names->fq_fmt,
+                                   name, sysdb->domain->name);
+        if (!src_name) return ENOMEM;
+    }
+
+    ret = sysdb_getgrnam(mem_ctx, sysdb, src_name ? src_name : name, res);
+    talloc_zfree(src_name);
+
+    return ret;
+}
diff --git a/src/providers/data_provider_be.c b/src/providers/data_provider_be.c
index 685c666a8..f4ad85365 100644
--- a/src/providers/data_provider_be.c
+++ b/src/providers/data_provider_be.c
@@ -2188,6 +2188,17 @@ int be_process_init(TALLOC_CTX *mem_ctx,
         goto fail;
     }
 
+    /* We need this for subdomains support, as they have to store fully
+     * qualified user and group names for now */
+    ret = sss_names_init(ctx->domain, cdb,
+                         ctx->domain->name, &ctx->domain->names);
+    if (ret != EOK) {
+        DEBUG(SSSDBG_FATAL_FAILURE,
+              ("fatal error setting fully qualified name format for %s\n",
+              ctx->domain->name));
+        goto fail;
+    }
+
     ret = be_srv_init(ctx);
     if (ret != EOK) {
         DEBUG(SSSDBG_FATAL_FAILURE, ("fatal error setting up server bus\n"));
diff --git a/src/providers/ipa/ipa_s2n_exop.c b/src/providers/ipa/ipa_s2n_exop.c
index 1a81c8609..8fc22819b 100644
--- a/src/providers/ipa/ipa_s2n_exop.c
+++ b/src/providers/ipa/ipa_s2n_exop.c
@@ -591,6 +591,9 @@ static void ipa_s2n_get_user_done(struct tevent_req *subreq)
     uint64_t timeout = 10*60*60; /* FIXME: find a better timeout ! */
     const char *homedir = NULL;
     struct sysdb_attrs *user_attrs = NULL;
+    char *name;
+    char *realm;
+    char *upn;
 
     ret = ipa_s2n_exop_recv(subreq, state, &result, &retoid, &retdata);
     talloc_zfree(subreq);
@@ -640,21 +643,64 @@ static void ipa_s2n_get_user_done(struct tevent_req *subreq)
                 goto done;
             }
 
-            ret = sysdb_attrs_add_string(user_attrs, SYSDB_NAME_ALIAS,
-                                         attrs->a.user.pw_name);
+            /* we always use the fully qualified name for subdomain users */
+            name = talloc_asprintf(state, state->dom->names->fq_fmt,
+                                   attrs->a.user.pw_name, state->dom->name);
+            if (!name) {
+                DEBUG(SSSDBG_OP_FAILURE, ("failed to format user name.\n"));
+                ret = ENOMEM;
+                goto done;
+            }
+
+            ret = sysdb_attrs_add_string(user_attrs, SYSDB_NAME_ALIAS, name);
+            if (ret != EOK) {
+                DEBUG(SSSDBG_OP_FAILURE, ("sysdb_attrs_add_string failed.\n"));
+                goto done;
+            }
+
+            /* We also have to store a fake UPN here, because otherwise the
+             * krb5 child later won't be able to properly construct one as
+             * the username is fully qualified but the child doesn't have
+             * access to the regex to deconstruct it */
+            /* FIXME: The real UPN is available from the PAC, we should get
+             * it from there. */
+            realm = get_uppercase_realm(state, state->dom->name);
+            if (!realm) {
+                DEBUG(SSSDBG_OP_FAILURE, ("failed to get realm.\n"));
+                ret = ENOMEM;
+                goto done;
+            }
+            upn = talloc_asprintf(state, "%s@%s",
+                                  attrs->a.user.pw_name, realm);
+            if (!upn) {
+                DEBUG(SSSDBG_OP_FAILURE, ("failed to format UPN.\n"));
+                ret = ENOMEM;
+                goto done;
+            }
+
+            ret = sysdb_attrs_add_string(user_attrs, SYSDB_UPN, upn);
             if (ret != EOK) {
                 DEBUG(SSSDBG_OP_FAILURE, ("sysdb_attrs_add_string failed.\n"));
                 goto done;
             }
 
-            ret = sysdb_store_domuser(state->dom, attrs->a.user.pw_name, NULL,
+            ret = sysdb_store_domuser(state->dom, name, NULL,
                                       attrs->a.user.pw_uid,
                                       0, NULL, /* gecos */
                                       homedir, NULL,
                                       user_attrs, NULL, timeout, now);
             break;
         case RESP_GROUP:
-            ret = sysdb_store_domgroup(state->dom, attrs->a.group.gr_name,
+            /* we always use the fully qualified name for subdomain users */
+            name = talloc_asprintf(state, state->dom->names->fq_fmt,
+                                   attrs->a.group.gr_name, state->dom->name);
+            if (!name) {
+                DEBUG(SSSDBG_OP_FAILURE, ("failed to format user name,\n"));
+                ret = ENOMEM;
+                goto done;
+            }
+
+            ret = sysdb_store_domgroup(state->dom, name,
                                        attrs->a.group.gr_gid, NULL, timeout,
                                        now);
             break;
diff --git a/src/responder/nss/nsssrv_cmd.c b/src/responder/nss/nsssrv_cmd.c
index a453e5937..db1efdd21 100644
--- a/src/responder/nss/nsssrv_cmd.c
+++ b/src/responder/nss/nsssrv_cmd.c
@@ -635,7 +635,7 @@ static int nss_cmd_getpwnam_search(struct nss_dom_ctx *dctx)
         dctx->domain = dom;
 
         talloc_free(name);
-        name = sss_get_cased_name(dctx, cmdctx->name, dom->case_sensitive);
+        name = sss_get_cased_name(cmdctx, cmdctx->name, dom->case_sensitive);
         if (!name) return ENOMEM;
 
         /* verify this user has not yet been negatively cached,
@@ -666,7 +666,9 @@ static int nss_cmd_getpwnam_search(struct nss_dom_ctx *dctx)
             return EIO;
         }
 
-        ret = sysdb_getpwnam(cmdctx, sysdb, name, &dctx->res);
+        /* if this is a subdomain we need to search for the fully qualified
+         * name in the database */
+        ret = sysdb_subdom_getpwnam(cmdctx, sysdb, name, &dctx->res);
         if (ret != EOK) {
             DEBUG(1, ("Failed to make request to our cache!\n"));
             return EIO;
@@ -2204,7 +2206,9 @@ static int nss_cmd_getgrnam_search(struct nss_dom_ctx *dctx)
             return EIO;
         }
 
-        ret = sysdb_getgrnam(cmdctx, sysdb, name, &dctx->res);
+        /* if this is a subdomain we need to search for the fully qualified
+         * name in the database */
+        ret = sysdb_subdom_getgrnam(cmdctx, sysdb, name, &dctx->res);
         if (ret != EOK) {
             DEBUG(1, ("Failed to make request to our cache!\n"));
             return EIO;
diff --git a/src/responder/pac/pacsrv_cmd.c b/src/responder/pac/pacsrv_cmd.c
index 5721d9262..202765a59 100644
--- a/src/responder/pac/pacsrv_cmd.c
+++ b/src/responder/pac/pacsrv_cmd.c
@@ -53,6 +53,7 @@ struct pac_req_ctx {
     struct pac_ctx *pac_ctx;
     const char *domain_name;
     const char *user_name;
+    char *fq_name;
     struct sss_domain_info *dom;
 
     struct PAC_LOGON_INFO *logon_info;
@@ -201,6 +202,16 @@ static errno_t pac_add_user_next(struct pac_req_ctx *pr_ctx)
     struct dom_sid *my_dom_sid;
     struct local_mapping_ranges *my_range_map;
 
+    /* this is a subdomain so we need to search for the fully qualified
+     * name in the database */
+    pr_ctx->fq_name = talloc_asprintf(pr_ctx, pr_ctx->dom->names->fq_fmt,
+                                      pr_ctx->user_name, pr_ctx->dom->name);
+    if (!pr_ctx->fq_name) {
+        ret = ENOMEM;
+        DEBUG(SSSDBG_OP_FAILURE, ("talloc_sprintf failed.\n"));
+        goto done;
+    }
+
     ret = save_pac_user(pr_ctx);
     if (ret != EOK) {
         DEBUG(SSSDBG_OP_FAILURE, ("save_pac_user failed.\n"));
@@ -365,7 +376,7 @@ static errno_t save_pac_user(struct pac_req_ctx *pr_ctx)
         goto done;
     }
 
-    ret = sysdb_search_user_by_name(tmp_ctx, sysdb, pr_ctx->user_name, attrs,
+    ret = sysdb_search_user_by_name(tmp_ctx, sysdb, pr_ctx->fq_name, attrs,
                                     &msg);
     if (ret == EOK) {
         /* TODO: check id uid and gid are equal. */
@@ -423,7 +434,7 @@ struct tevent_req *pac_save_memberships_send(struct pac_req_ctx *pr_ctx)
     }
 
     state->gid_iter = 0;
-    state->user_dn = sysdb_user_dn(dom->sysdb, state, pr_ctx->user_name);
+    state->user_dn = sysdb_user_dn(dom->sysdb, state, pr_ctx->fq_name);
     if (state->user_dn == NULL) {
         ret = ENOMEM;
         goto done;
diff --git a/src/responder/pac/pacsrv_utils.c b/src/responder/pac/pacsrv_utils.c
index c9551c998..53113fb0d 100644
--- a/src/responder/pac/pacsrv_utils.c
+++ b/src/responder/pac/pacsrv_utils.c
@@ -502,6 +502,7 @@ errno_t get_pwd_from_pac(TALLOC_CTX *mem_ctx,
     struct sysdb_attrs *attrs = NULL;
     struct netr_SamBaseInfo *base_info;
     int ret;
+    char *lname;
     char *uc_realm;
     char *upn;
 
@@ -513,36 +514,41 @@ errno_t get_pwd_from_pac(TALLOC_CTX *mem_ctx,
 
     base_info = &logon_info->info3.base;
 
-    if (base_info->account_name.size != 0) {
-        /* To be compatible with winbind based lookups we have to use lower
-         * case names only, effectively making the domain case-insenvitive. */
-        pwd->pw_name = sss_tc_utf8_str_tolower(pwd,
-                                               base_info->account_name.string);
-        if (pwd->pw_name == NULL) {
-            DEBUG(SSSDBG_OP_FAILURE, ("sss_tc_utf8_str_tolower failed.\n"));
-            ret = ENOMEM;
-            goto done;
-        }
-    } else {
+    if (base_info->account_name.size == 0) {
         DEBUG(SSSDBG_OP_FAILURE, ("Missing account name in PAC.\n"));
         ret = EINVAL;
         goto done;
     }
-
-    if (base_info->rid > 0) {
-        ret = domsid_rid_to_uid(pac_ctx, dom->sysdb, dom->name,
-                                base_info->domain_sid,
-                                base_info->rid, &pwd->pw_uid);
-        if (ret != EOK) {
-            DEBUG(SSSDBG_OP_FAILURE, ("domsid_rid_to_uid failed.\n"));
-            goto done;
-        }
-    } else {
+    if (base_info->rid == 0) {
         DEBUG(SSSDBG_OP_FAILURE, ("Missing user RID in PAC.\n"));
         ret = EINVAL;
         goto done;
     }
 
+    /* To be compatible with winbind based lookups we have to use lower
+     * case names only, effectively making the domain case-insenvitive. */
+    lname = sss_tc_utf8_str_tolower(pwd, base_info->account_name.string);
+    if (lname == NULL) {
+        DEBUG(SSSDBG_OP_FAILURE, ("sss_tc_utf8_str_tolower failed.\n"));
+        ret = ENOMEM;
+        goto done;
+    }
+    pwd->pw_name = talloc_asprintf(pwd, dom->names->fq_fmt,
+                                   lname, dom->name);
+    if (!pwd->pw_name) {
+        DEBUG(SSSDBG_OP_FAILURE, ("talloc_sprintf failed.\n"));
+        ret = ENOMEM;
+        goto done;
+    }
+
+    ret = domsid_rid_to_uid(pac_ctx, dom->sysdb, dom->name,
+                            base_info->domain_sid,
+                            base_info->rid, &pwd->pw_uid);
+    if (ret != EOK) {
+        DEBUG(SSSDBG_OP_FAILURE, ("domsid_rid_to_uid failed.\n"));
+        goto done;
+    }
+
     pwd->pw_gid = 0; /* We use MPGs for sub-domains */
 
     if (base_info->full_name.size != 0) {
@@ -559,7 +565,7 @@ errno_t get_pwd_from_pac(TALLOC_CTX *mem_ctx,
 
     if (dom->subdomain_homedir) {
         pwd->pw_dir = expand_homedir_template(pwd, dom->subdomain_homedir,
-                                              pwd->pw_name, pwd->pw_uid,
+                                              lname, pwd->pw_uid,
                                               dom->name);
         if (pwd->pw_dir == NULL) {
             ret = ENOMEM;
@@ -583,7 +589,7 @@ errno_t get_pwd_from_pac(TALLOC_CTX *mem_ctx,
         goto done;
     }
 
-    upn = talloc_asprintf(mem_ctx, "%s@%s", pwd->pw_name, uc_realm);
+    upn = talloc_asprintf(mem_ctx, "%s@%s", lname, uc_realm);
     talloc_free(uc_realm);
     if (upn == NULL) {
         DEBUG(SSSDBG_OP_FAILURE, ("talloc_asprintf failed.\n"));
diff --git a/src/responder/pam/pamsrv_cmd.c b/src/responder/pam/pamsrv_cmd.c
index 1702a0e91..426964220 100644
--- a/src/responder/pam/pamsrv_cmd.c
+++ b/src/responder/pam/pamsrv_cmd.c
@@ -1217,7 +1217,10 @@ static int pam_check_user_search(struct pam_auth_req *preq)
             preq->pd->pam_status = PAM_SYSTEM_ERR;
             return EFAULT;
         }
-        ret = sysdb_getpwnam(preq, sysdb, name, &preq->res);
+
+        /* if this is a subdomain we need to search for the fully qualified
+         * name in the database */
+        ret = sysdb_subdom_getpwnam(preq, sysdb, name, &preq->res);
         if (ret != EOK) {
             DEBUG(1, ("Failed to make request to our cache!\n"));
             return EIO;
diff --git a/src/util/domain_info_utils.c b/src/util/domain_info_utils.c
index 6ee354552..a6aa5c733 100644
--- a/src/util/domain_info_utils.c
+++ b/src/util/domain_info_utils.c
@@ -73,7 +73,7 @@ struct sss_domain_info *new_subdomain(TALLOC_CTX *mem_ctx,
     }
 
     dom->enumerate = false;
-    dom->fqnames = true;
+    dom->fqnames = false;
     /* FIXME: get ranges from the server */
     dom->id_min = 0;
     dom->id_max = 0xffffffff;