plugin-runner: too many arguments

[DaRkBoDoM]

Hi again,

i've solved with this patch.

How do i submit it for merge?


=== modified file 'plugin-runner.c'
--- old/plugin-runner.c 2021-03-21 18:48:43 +0000
+++ new/plugin-runner.c 2022-02-26 22:14:35 +0000
@@ -605,17 +605,16 @@
   * "case" to the "parse_opt_config_file" function below.
   */
      case ARGP_KEY_ARG:
-      /* Cryptsetup always passes an argument, which is an empty
-        string if "none" was specified in /etc/crypttab.  So if
-        argument was empty, we ignore it silently. */
-      if(arg[0] == '\0'){
-       break;
+      /* Cryptsetup passes an argument, which is an empty string if 
"none" was
+         specified in /etc/crypttab or the value of key field. When the
+         keyscript is specified directly in the boot command line, it also
+         passes an argument. Just ignoring any argument.
+      */
+      if(arg[0] != '\0'){
+        // Emit a warning for non-empty argument
+        fprintf(stderr, "ignoring argument: %s\n", arg);
        }
-#if __GNUC__ >= 7
-      __attribute__((fallthrough));
-#else
-         /* FALLTHROUGH */
-#endif
+      break;
      default:
        return ARGP_ERR_UNKNOWN;
      }
Il 20/02/22 15:23, DaRkBoDoM ha scritto:
> Hi there!
> 
> I am trying to setup mandos for automatic reboot on Raspberry OS 
> (formerly Raspian).
> 
> I am following this (old?) totorial: 
> https://blog.boyeau.com/booting-an-unattended-full-disk-encrypted-server-ubuntu-server-16-04-setup-with-mandos/ 
> 
> 
> I have tried adding
> # <target name> <source device>         <key file>      <options>
> crypt /dev/disk/by-uuid/my-uuid none 
> luks,keyscript=/usr/lib/mandos/plugin-runner
> 
> to /etc/crypttab but when i rebuild the initrd i get the error 
> "cryptsetup: ERROR: crypt: invalid value for 'keyscript' option, skipping"
> 
> couldn't figure out what is wrong, so i fell back to adding the 
> keyscript in the kernel cmdline:
> 
> root=/dev/mapper/crypt cryptdevice=/dev/mmcblk0p3:crypt 
> cryptopts=source=/dev/mmcblk0p3,target=crypt,keyscript=/usr/lib/mandos/plugin-runner 
> rootfstype=ext4 fsck.repair=yes rootwait
> 
> this works: plugin-runner is correctly invoked but i get a 
> "plugin-runner: Too many arguments
> Try `plugin-runner --help` or `plugin-runner --usage` for more information.
> Going to fallback mode using getpass(3)
> Password:" error.
> 
> I've tried many solutions, but i am stuck.
> 
> Looks like the plugin-runner is asking for the secret anyway in 
> background (and getting it from the server). In the server log i can find:
> 2022-02-20 15:14:24,307 root [34623]: INFO: Sending secret to osgiliath
> 
> While the client is still waiting for the password prompt.
> 
> May i get an hint on how to solve this? Looks like i am stuck at just 
> one step from finish line.
> 
> Bonus question: is there an option to disable the checker and automatic 
> client disabling? It is a very nice feature, but i do not need it since 
> i have strong physical security measures in place: if my raspberry gets 
> stolen, i will certainly notice and disable it manually long before any 
> attacker could realize hot to ask the server for the key.
> 
> Thank you for writing and sharing this very nice software!
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