From 3a18e33f983cd17860b6ff41f9d538ee8fcc6d98 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Pavel=20B=C5=99ezina?= <pbrezina@redhat.com>
Date: Wed, 27 Feb 2019 14:06:06 +0100
Subject: [PATCH 6/6] sudo: format runas attributes to correct output name

sudo internally calls getpwnam and getgrnam on user and groups
that should be used for the invoked command. Output of these calls
is compared to values in runAsUser/Group attributes.

When different output format is used then what is present in LDAP,
this comparison will fail, denying user to use sudo. Now, we convert
these attributes into correct output name, respecting domain resolution
order, fully qualified domains and fqname format.

E.g. sudo call:
sudo -u tuser@ipa.vm -g tgroup@ipa.vm id

Resolves:
https://pagure.io/SSSD/sssd/issue/3957

Reviewed-by: Jakub Hrozek <jhrozek@redhat.com>
(cherry picked from commit 0aa657165f189035c160beda4840e3271fc56c88)
---
 src/responder/sudo/sudosrv_get_sudorules.c | 101 ++++++++++++++++++++-
 1 file changed, 99 insertions(+), 2 deletions(-)

diff --git a/src/responder/sudo/sudosrv_get_sudorules.c b/src/responder/sudo/sudosrv_get_sudorules.c
index a420c76fb..d928a5ead 100644
--- a/src/responder/sudo/sudosrv_get_sudorules.c
+++ b/src/responder/sudo/sudosrv_get_sudorules.c
@@ -113,6 +113,95 @@ sort_sudo_rules(struct sysdb_attrs **rules, size_t count, bool lower_wins)
     return EOK;
 }
 
+static errno_t sudosrv_format_runas(struct resp_ctx *rctx,
+                                    struct sysdb_attrs *rule,
+                                    const char *attr)
+{
+    TALLOC_CTX *tmp_ctx;
+    struct ldb_message_element *el;
+    struct sss_domain_info *dom;
+    const char *value;
+    char *fqname;
+    unsigned int i;
+    errno_t ret;
+
+    tmp_ctx = talloc_new(NULL);
+    if (tmp_ctx == NULL) {
+        DEBUG(SSSDBG_FATAL_FAILURE, "Out of memory!\n");
+        return ENOMEM;
+    }
+
+    ret = sysdb_attrs_get_el_ext(rule, attr, false, &el);
+    if (ret == ENOENT) {
+        ret = EOK;
+        goto done;
+    } else if (ret != EOK) {
+        DEBUG(SSSDBG_CRIT_FAILURE, "Unable to get %s attribute "
+              "[%d]: %s\n", attr, ret, sss_strerror(ret));
+        goto done;
+    }
+
+    for (i = 0; i < el->num_values; i++) {
+        value = (const char *)el->values[i].data;
+        if (value == NULL) {
+            continue;
+        }
+
+        dom = find_domain_by_object_name_ex(rctx->domains, value, true);
+        if (dom == NULL) {
+            continue;
+        }
+
+        ret = sss_output_fqname(tmp_ctx, dom, value,
+                                rctx->override_space, &fqname);
+        if (ret != EOK) {
+            DEBUG(SSSDBG_CRIT_FAILURE, "Unable to convert %s to output fqname "
+                  "[%d]: %s\n", value, ret, sss_strerror(ret));
+            goto done;
+        }
+
+        talloc_free(el->values[i].data);
+        el->values[i].data = (uint8_t*)talloc_steal(el->values, fqname);
+        el->values[i].length = strlen(fqname);
+    }
+
+done:
+    talloc_free(tmp_ctx);
+
+    return ret;
+}
+
+static errno_t sudosrv_format_rules(struct resp_ctx *rctx,
+                                    struct sysdb_attrs **rules,
+                                    uint32_t num_rules)
+{
+    uint32_t i;
+    errno_t ret;
+
+
+    for (i = 0; i < num_rules; i++) {
+        ret = sudosrv_format_runas(rctx, rules[i],
+                                   SYSDB_SUDO_CACHE_AT_RUNAS);
+        if (ret != EOK) {
+            return ret;
+        }
+
+        ret = sudosrv_format_runas(rctx, rules[i],
+                                   SYSDB_SUDO_CACHE_AT_RUNASUSER);
+        if (ret != EOK) {
+            return ret;
+        }
+
+        ret = sudosrv_format_runas(rctx, rules[i],
+                                   SYSDB_SUDO_CACHE_AT_RUNASGROUP);
+        if (ret != EOK) {
+            return ret;
+        }
+    }
+
+    return ret;
+}
+
 static errno_t sudosrv_query_cache(TALLOC_CTX *mem_ctx,
                                    struct sss_domain_info *domain,
                                    const char **attrs,
@@ -301,6 +390,7 @@ static errno_t sudosrv_cached_rules_by_ng(TALLOC_CTX *mem_ctx,
 }
 
 static errno_t sudosrv_cached_rules(TALLOC_CTX *mem_ctx,
+                                    struct resp_ctx *rctx,
                                     struct sss_domain_info *domain,
                                     uid_t cli_uid,
                                     uid_t orig_uid,
@@ -368,6 +458,12 @@ static errno_t sudosrv_cached_rules(TALLOC_CTX *mem_ctx,
         goto done;
     }
 
+    ret = sudosrv_format_rules(rctx, rules, num_rules);
+    if (ret != EOK) {
+        DEBUG(SSSDBG_OP_FAILURE, "Could not format sudo rules\n");
+        goto done;
+    }
+
     *_rules = talloc_steal(mem_ctx, rules);
     *_num_rules = num_rules;
 
@@ -412,6 +508,7 @@ static errno_t sudosrv_cached_defaults(TALLOC_CTX *mem_ctx,
 }
 
 static errno_t sudosrv_fetch_rules(TALLOC_CTX *mem_ctx,
+                                   struct resp_ctx *rctx,
                                    enum sss_sudo_type type,
                                    struct sss_domain_info *domain,
                                    uid_t cli_uid,
@@ -433,7 +530,7 @@ static errno_t sudosrv_fetch_rules(TALLOC_CTX *mem_ctx,
               username, domain->name);
         debug_name = "rules";
 
-        ret = sudosrv_cached_rules(mem_ctx, domain,
+        ret = sudosrv_cached_rules(mem_ctx, rctx, domain,
                                    cli_uid, orig_uid, username, groups,
                                    inverse_order, &rules, &num_rules);
 
@@ -760,7 +857,7 @@ static void sudosrv_get_rules_done(struct tevent_req *subreq)
               "in cache.\n");
     }
 
-    ret = sudosrv_fetch_rules(state, state->type, state->domain,
+    ret = sudosrv_fetch_rules(state, state->rctx, state->type, state->domain,
                               state->cli_uid,
                               state->orig_uid,
                               state->orig_username,
-- 
2.19.1