homed,userdbd: mark "secrets" section of user records always to "sensitive" (#37935)

src/home/homectl-pkcs11.c

@@ -50,6 +50,8 @@ int identity_add_token_pin(sd_json_variant **v, const char *pin) {
         if (r < 0)
                 return log_error_errno(r, "Failed to update PIN field: %m");
 
+        sd_json_variant_sensitive(w);
+
         r = sd_json_variant_set_field(v, "secret", w);
         if (r < 0)
                 return log_error_errno(r, "Failed to update secret object: %m");

src/home/homectl-recovery-key.c

@@ -94,6 +94,8 @@ static int add_secret(sd_json_variant **v, const char *password) {
         if (r < 0)
                 return log_error_errno(r, "Failed to update password field: %m");
 
+        sd_json_variant_sensitive(w);
+
         r = sd_json_variant_set_field(v, "secret", w);
         if (r < 0)
                 return log_error_errno(r, "Failed to update secret object: %m");

src/home/homed-home.c

@@ -1256,6 +1256,8 @@ static int home_start_work(
                 if (!sub)
                         return -ENOKEY;
 
+                sd_json_variant_sensitive(sub);
+
                 r = sd_json_variant_set_field(&v, "secret", sub);
                 if (r < 0)
                         return r;

src/home/user-record-util.c

@@ -1022,8 +1022,11 @@ int user_record_set_fido2_user_presence_permitted(UserRecord *h, int b) {
 
         if (sd_json_variant_is_blank_object(w))
                 r = sd_json_variant_filter(&h->json, STRV_MAKE("secret"));
-        else
+        else {
+                sd_json_variant_sensitive(w);
+
                 r = sd_json_variant_set_field(&h->json, "secret", w);
+        }
         if (r < 0)
                 return r;
 
@@ -1050,8 +1053,11 @@ int user_record_set_fido2_user_verification_permitted(UserRecord *h, int b) {
 
         if (sd_json_variant_is_blank_object(w))
                 r = sd_json_variant_filter(&h->json, STRV_MAKE("secret"));
-        else
+        else {
+                sd_json_variant_sensitive(w);
+
                 r = sd_json_variant_set_field(&h->json, "secret", w);
+        }
         if (r < 0)
                 return r;
 

src/shared/user-record.c

@@ -1531,6 +1531,11 @@ int user_group_record_mangle(
         if (USER_RECORD_STRIP_MASK(load_flags) == _USER_RECORD_MASK_MAX) /* strip everything? */
                 return json_log(v, json_flags, SYNTHETIC_ERRNO(EINVAL), "Stripping everything from record, refusing.");
 
+        /* Extra safety: mark the "secret" part (that contains literal passwords and such) as sensitive, so
+         * that it is not included in debug output and erased from memory when we are done. We do this for
+         * any record that passes through here. */
+        sd_json_variant_sensitive(sd_json_variant_by_key(v, "secret"));
+
         /* Check if we have the special sections and if they match our flags set */
         FOREACH_ELEMENT(i, mask_field) {
                 sd_json_variant *e, *k;