sysdb: try dealing with binary-content attributes

https://fedorahosted.org/sssd/ticket/1818

I have here a LDAP user entry which has this attribute

	loginAllowedTimeMap::
	 AAAAAAAAAP///38AAP///38AAP///38AAP///38AAP///38AAAAAAAAA

In the function sysdb_attrs_add_string(), called from
sdap_attrs_add_ldap_attr(), strlen() is called on this blob, which is
the wrong thing to do. The result of strlen is then used to populate
the .v_length member of a struct ldb_val - and this will set it to
zero in this case. (There is also the problem that there may not be
a '\0' at all in the blob.)

Subsequently, .v_length being 0 makes ldb_modify(), called from
sysdb_set_entry_attr(), return LDB_ERR_INVALID_ATTRIBUTE_SYNTAX. End
result is that users do not get stored in the sysdb, and programs like
`id` or `getent ...` show incomplete information.

The bug was encountered with sssd-1.8.5. sssd-1.5.11 seemed to behave
fine, but that may not mean that is the absolute lower boundary of
introduction of the problem.

4 files changed, 17 insertions, 7 deletions

diff --git a/src/db/sysdb.c b/src/db/sysdb.c
index b0bea9a73..729e10e33 100644
--- a/src/db/sysdb.c
+++ b/src/db/sysdb.c
@@ -511,6 +511,16 @@ int sysdb_attrs_add_string(struct sysdb_attrs *attrs,
     return sysdb_attrs_add_val(attrs, name, &v);
 }
 
+int sysdb_attrs_add_mem(struct sysdb_attrs *attrs, const char *name,
+                        const void *mem, size_t size)
+{
+	struct ldb_val v;
+
+	v.data   = discard_const(mem);
+	v.length = size;
+	return sysdb_attrs_add_val(attrs, name, &v);
+}
+
 int sysdb_attrs_add_bool(struct sysdb_attrs *attrs,
                          const char *name, bool value)
 {
diff --git a/src/db/sysdb.h b/src/db/sysdb.h
index db6748cff..8445ebaac 100644
--- a/src/db/sysdb.h
+++ b/src/db/sysdb.h
@@ -280,6 +280,8 @@ int sysdb_attrs_add_val(struct sysdb_attrs *attrs,
                         const char *name, const struct ldb_val *val);
 int sysdb_attrs_add_string(struct sysdb_attrs *attrs,
                            const char *name, const char *str);
+int sysdb_attrs_add_mem(struct sysdb_attrs *, const char *,
+                        const void *, size_t);
 int sysdb_attrs_add_bool(struct sysdb_attrs *attrs,
                          const char *name, bool value);
 int sysdb_attrs_add_long(struct sysdb_attrs *attrs,
diff --git a/src/providers/ldap/sdap.c b/src/providers/ldap/sdap.c
index 371121b2c..dba4e41db 100644
--- a/src/providers/ldap/sdap.c
+++ b/src/providers/ldap/sdap.c
@@ -343,7 +343,6 @@ errno_t sdap_parse_deref(TALLOC_CTX *mem_ctx,
     const char **ocs;
     struct sdap_attr_map *map;
     int num_attrs;
-    struct ldb_val v;
     int ret, i, a, mi;
     const char *name;
     size_t len;
@@ -474,10 +473,9 @@ errno_t sdap_parse_deref(TALLOC_CTX *mem_ctx,
             for (i=0; dval->vals[i].bv_val; i++) {
                 DEBUG(9, ("Dereferenced attribute value: %s\n",
                           dval->vals[i].bv_val));
-                v.data = (uint8_t *) dval->vals[i].bv_val;
-                v.length = dval->vals[i].bv_len;
-
-                ret = sysdb_attrs_add_val(res[mi]->attrs, name, &v);
+                ret = sysdb_attrs_add_mem(res[mi]->attrs, name,
+                                          dval->vals[i].bv_val,
+                                          dval->vals[i].bv_len);
                 if (ret) goto done;
             }
         }
diff --git a/src/providers/ldap/sdap_async.c b/src/providers/ldap/sdap_async.c
index e0440625d..862723ddc 100644
--- a/src/providers/ldap/sdap_async.c
+++ b/src/providers/ldap/sdap_async.c
@@ -2226,8 +2226,8 @@ sdap_attrs_add_ldap_attr(struct sysdb_attrs *ldap_attrs,
             DEBUG(SSSDBG_TRACE_INTERNAL, ("Adding %s [%s] to attributes "
                   "of [%s].\n", desc, el->values[i].data, objname));
 
-            ret = sysdb_attrs_add_string(attrs, attr_name,
-                                         (const char *) el->values[i].data);
+            ret = sysdb_attrs_add_mem(attrs, attr_name, el->values[i].data,
+                                      el->values[i].length);
             if (ret) {
                 return ret;
             }