users November 2021

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13 participants
8 discussions

CBE key encryption
by Stefan Thöni 19 Dec '21

19 Dec '21

Hello Genodians, we are still working to add hardware-based encryption to CBE. To this end, we have implemented a custom trust anchor and crypto engine. Generating a key, encrypting this key on behalf of cbe_init and decrypting it again on behalf of the vfs_cbe plugin works fine. But then the vfs_cbe requests to have a all zero key encrypted which due to the ICV added by hardware black key handling fails. We cannot seam to find out where the request originates or why vfs_cbe would ever encrypt any key, let alone a key of all zeros. Any pointer or idea would by very welcome. Kind regards Stefan

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VFS plug-in that requires early libc initialization (for FUSE)
by ttcoder＠netcourrier.com 08 Dec '21

08 Dec '21

Hey Genode team, fellow Genodians, I'm trying to modify FUSE-server to become a VFS plug-in (see genode-world#193) but it seems "with_libc()" no longer works, when in a plug-in attached to the test-libc_vfs test harness: [init -> test-libc_vfs] ---->open_Dir [init -> test-libc_vfs] Error: Uncaught exception of type 'Libc::Kernel::Kernel_called_prior_initialization' [init -> test-libc_vfs] Warning: abort called - thread: ep Questions: --------- Seems a VFS plug-in is initialized first, before libc has had a chance to be initialized ? While digging in the code, here is what I can gather: in the previous incarnation of the code, where FUSE is an FS server, the server would call Libc::Component::construct() early, which would initialize the libc/kernel: kernel = *unmanaged_singleton<Libc::Kernel>(..) and then subsequent calls to libc would work. But now, the VFS plug-in (and its libc-using code) is called first. Is that the right explanation for my problem? Alternative explanation: maybe the libc framework from the _host_ component is not shared with its child VFS plug-in at all ? Tracing: ------- I then removed calls to libc, and added some tracing to the now free-flowing code, to get some sense of chronology, determine who is called when. The result was interesting: it seems when a VFS plug-in is instantiated, its hooks are called before anything else is called (I'm not the one calling them, as my code is still at an early "skeleton" stage yet, I make no call to opendir() etc, so someone else is doing that), including even before the host "Main" : [init -> test-libc_vfs] ---->open_Dir [init -> test-libc_vfs] ---->num_dirent [init -> test-libc_vfs] ---->directory [init -> test-libc_vfs] ---->directory [init -> acpi_drv] SMBIOS table (entry point: 0x165700 structures: 0xf5720) [init -> platform_drv] ECAM/MMCONF range 00000000:00000000.0-000000ff:0000001f.7 - addr [00000000b0000000,00000000c0000000) [init -> test-libc_vfs] test-libc-vfs: ctor of struct Main : reading config ROM [init -> test-libc_vfs] test-libc-vfs: entering with_libc() [init -> test-libc_vfs] test-libc-vfs: calling test() from libc context [init -> test-libc_vfs] ---->leaf_path [init -> test-libc_vfs] Error: Uncaught exception of type 'Test_failed' So based on that 'evidence' alone, it would seem the event chronology is somewhat like this: - test-harness is loaded by LD - LD looks for its plugins, loads them, and executes them first (even if they require libc) - test-harness / struct Main is called, initializing libc etc Maybe my FUSE plug-in should detect when libc is not yet initialized, reject all calls to its hooks done at that early time, and only honor them later on ? Cedric

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[Proposal] How to work with passwords in genode
by Uwe 30 Nov '21

30 Nov '21

Hello all, I have done some work for specifying a way to use passwords to connect two instances of genode. The most work was done in minimalizing the codebase that is needed to implement all functionality. Nevertheless I'm not sure I have found the point of minimal (algorithmic) complexity. Therefore I want to describe the point found (with rationale) and listen to comments before doing further work in this direction. First I represent all strings in the protocol as their hashes turned into points on an elliptic curve. Rationale: Because curve points are needed anyway to encrypt the traffic between the two instances of genode and in this protocol at least partly represent the connected parties I want to reuse that in the password protocol. Second I want to associate every PD with a secret key, that is only available to that PD. For this I would propose that core should host an implementation of the PBKDF2 function with a fixed salt. This function should turn the trusted path of its client into a cryptographic random string. This string can then be used to produce individual and stable cryptographic keys in every component that uses this functionality. To reuse as much functionality as possible I would propose to use a ROM session with a special name ("keysalt" comes to mind) to implement this functionality. Rationale: I would expect that in the future many components will need to store cryptographic material from shutdown to boot. Therefore a central facility to help there could be advantagous. Third I want to be able to externally configure the connections with as much privacy as possible. That privacy comes in handy when it is needed to store passwords. Rationale: Especially in embedded there may not be a possibility to enter connection information. And I don't want to have to implement two different protocols for the same functionality. I think this makes this the most general description of my approach: Name all items (computer, components, user, passwords) with points on an elliptic curve with known logarithms. Connect them with a data structure that encrypts that connection in such a way that this connection is only visible to those who are connected, expressed as those who know the relevant logarithms. Now a little more detail: The most important information needed to understand the concept is the construction of the connecting data structure. It consists of three points on an elliptic curve. Two of them are simple. I will describe this structure by giving the algorithm to compute it. First you have the points A and B which name the proverbial Alice and Bob, the items which should be connected. You need to compute the points K,R and C which make up the data structure. 1. Choose a random point on the elliptic curve and name it R. (I said it was simple :-) 2. Choose a random scalar k, multiply it with the generator G and name the result K. (Two points down and hardly a sweat. And independend of A or B!) 3. Compute R-kA and call it D. 4. Also compute R-kB and call it E. 5. Hash D (with possibly some identifying string for Alice) to a scalar d. 6. Hash E (with possibly some identifying string for Bob) to a scalar e. 7. Compute k(eB+dA) and name this point C. The data structure consists of the points K,R and C and the identifying information used in the hash (possibly implicit). To use that information Alice (for example) computes this: 1. Compute R-aK and call it D. 2. Hash D (with identifying information) to scalar d. 3. Compute C-daK (where 'a' is the private key to A) and call it F. 4. Compute daF and call it M. M is the same point for both A and B but not for other keys. >From M there can be calculated a common key and a common string for connecting (for instance a channel on IRC). Over this a method for more direct communication (for instance DCC) can be negotiated. Of course encrypted. Or in the case of a password M can be used in a PAKE implementation. Now to the mapping of items to points: - component This component runs in a PD. That PD is associated (via "keysalt") with keying material. From this a public key can be calculated and that point will be the name of the component. - computer There needs to be a component that makes the computer available on the network. The key of this component is modified by multiplying with its own secret key to make a difference between the name of the computer and the name of any component. - user The users name string is hashed with the point that names the computer where the user is registered. That makes users name point unique even in case of the same name string. Because that scalar is not really secret the point derived from this can not be used as a key. Not even in the connection data described above. But it can be encrypted with ElGamal and used to lookup records in a database. - password The users name point is hashed together with the password string to a scalar. This scalar is divided by a random scalar and multiplied with the name point of the computer where the multiplicator is stored. The resulting point must be transfered together with the name point of the user to the computer where the multiplicator is stored. That computer looks up the record of the user with its name point. When it has found the record it checks the last access time and waits a little bit and returns the provisonally password point multiplied with the multiplicator. If no record is found the users name point is hashed together with some secret key to compute a fake multiplicator. In every case a point for the calculation of a password point is returned after a delay. (Rationale: By splitting the password and delaying the calculation a brute force attac is legthened into impractical times.) The returned point is then multiplied with the random scalar from above and the result is then hashed again with the password string to the password scalar. That password scalar is then multiplied with the generator point to obtain the password point. This password point is only used to generate a connecting data structure together with the component name point of the component that is authenticated to. And the password scalar is needed to open this connecting data structure. The connecting data structure is stored in a record together with the users name point and returned if questioned with the (encrypted) users name point. Rationale for making hashes dependent on points: In the password algorithm it protects against some esoteric cases of password theft. Maybe the connection data structure protects as well but I leave them in because double protection is better than faulty protection. And when this is implemented anyway I would want to use the same routine for all hashes and use the points for domain separation (or the string in case of M). It can also protect against faults in the hash algorithm. For instance SHA1 is broken, HMAC-SHA1 is not,last I heard. So I would opt for using the pattern of HMAC with the point as key. I hope I didn't overwhelm you with so many details. But I think they are needed to get an idea of the direction I think is the most advantageous. If you think the most advantageous lies in another direction entirely, please tell me so. If you need more details please ask. But I wont promise a satisfying answer in short time because I would have first to think about it. But I have some inkling of the direction(s) that are possible so a handwavey answer is possible in short time. So if you ask, please include some indication which way lay your preferences for the answer.

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Announcement: Genode OS Framework version 21.11 released
by Norman Feske 30 Nov '21

30 Nov '21

Today, we released the version 21.11 of the Genode OS Framework: https://genode.org/news/genode-os-framework-release-21.11 During this release cycle, we focused on device drivers. Thanks to the new DDE-Linux approach featured by the previous release, we were able to transplant the display and touchscreen drivers for the Pinephone from the Linux kernel to Genode. The drivers are reused without modifications, but each one is sandboxed independently as a separate component. The i.MX8 SoC family enjoys the most comprehensive Genode support among the 64-bit ARM platforms. The new version advances the driver coverage further by the means of a new USB host-controller driver that improves the performance of isochronous devices like webcams, and a new GPU driver for the Vivante GPU. Speaking of GPUs, we maintained the steady pace of our work on hardware-accelerated graphics and are proud the announce the support for Intel Gen9 and newer GPUs by our custom Intel GPU multiplexer. The topics outlined above barely scratch the surface. For the whole picture, please enjoy skimming the release documentation linked below. The major improvement at a glance: - Modularization of Genode's board-support code base - Drivers - Interactive scenarios on the Pinephone (touch + graphics) - New USB driver for NXP i.MX8 - New Vivante GPU driver and etnaviv Mesa driver - New VirtIO input and framebuffer drivers - Hardware-accelerated graphics with Intel Gen9+ GPUs - New support for the Xilinx Zynq-based USRP E310 board - Feature completion of VirtualBox 6 - Sculpt OS for 64-bit ARM in addition to x86 - Audio and OpenGL support for libSDL2 - Automated boot-image creation for i.MX8, Zynq, Allwinner The full documentation of the changes is available here: https://genode.org/documentation/release-notes/21.11 Enjoy the new version! Norman -- Dr.-Ing. Norman Feske Genode Labs https://www.genode-labs.com · https://genode.org Genode Labs GmbH · Amtsgericht Dresden · HRB 28424 · Sitz Dresden Geschäftsführer: Dr.-Ing. Norman Feske, Christian Helmuth

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Wacom Touchscreen / Pen Driver
by John J. Karcher 28 Nov '21

28 Nov '21

Hello, I was just wondering if anyone has had the itch to finish converting the Wacom touchscreen / pen driver, possibly with the benefit of the newer Linux driver conversion tools? I've tried a couple of times, but it's beyond my skill set (and time to learn). Thanks! -- John J. Karcher devuser(a)alternateapproach.com

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Questions regarding Issue #4323
by Costin Grigore 18 Nov '21

18 Nov '21

Hello, I'm a final year CS B.S. student. I was looking for an interesting project / thesis for my Bachelor and my professor suggested I take a look into Genode (besides other things). I find the project fascinating, even though I don't nearly possess enough information to fully understand it. Browsing through the issue tracker, I saw Issue #4323, regarding a possible memory leak. To my understanding, this would be a very easy fix, just free the void pointer that was allocated. Is that enough? I've also found one other place (and there could be more) where this happens again. The same idea -> allocated memory that doesn't get deallocated if the mapping fails. How should I go about helping with this? Search for such spots and add a deallocation for each I find, then create a pull request? Thanks in advance, Costinteo

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Current status of genode golang port
by Alexander Tormasov 04 Nov '21

04 Nov '21

Implemented experimental stack switch for current genode 21.08/gcc10.3 (by opaque structure Thread rewriting) during setcontext() Works for many CPU, with gcc optimization turned on (tested on 4) on NOVA and linux x86_64, sometimes works on sel4 To run need 2 repos: https://github.com/tor-m6/genode.git (Need to checkout 21.08 branch) https://github.com/tor-m6/genode-world.git (Need to checkout 21.08experimental) I successfully run some tests with channels/async goroutines - some of them (Like Hanoi towers or barber serving) inside https://github.com/tor-m6/genode-world/blob/21.08experimental/src/test/go_a… All of them commented out - you can compile any between «package main» lines, or try your own More details in https://github.com/tor-m6/genode-world/blob/21.08experimental/src/test/go_a… Note 1: As pointed by Use, I know that potentially it could fail if you try to acquire genode resources/caps directly from go code, while all tests and anything backend by libc port should work. Note 2: sel4 problem: on my working copy it works always, while fresh rebuild fail during golang stack unwind - because of guard page «edge» access. Still not able to debug… Question: how to print call stack from page fault? Error message below, I need to understand a reason, not just place - I know it inside function _Unwind_GetGR(): /genodelabs-genode-c0150f9/contrib/gcc-bc8a730adbf377de2c449d222a0df0ba7096a4b8/src/noux-pkg/gcc/libgcc/unwind-dw2.c:234 Warning: page-fault, pager_object: pd='init -> test-go' thread='ep' ip=0x112938f pf-addr=0x403ff008 Sincerely, Alexander

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usb_modem and mbimcli
by Duss Pirmin 04 Nov '21

04 Nov '21

Hello Genodians I have a SIMCOM 7600G mPCI modem, which I have configured to use MBIM mode. The device is recognized by `usb_drv` as follows: ``` <device label="usb-1-4" vendor_id="0x1e0e" product_id="0x9003" bus="0x1" dev="0x4" class="0xff"> <interface class="0xff" protocol="0xff"/> <interface class="0xff" protocol="0x0"/> <interface class="0xff" protocol="0x0"/> <interface class="0xff" protocol="0x0"/> <interface class="0xff" protocol="0x0"/> <interface class="0x2" protocol="0x0"/> <interface class="0xa" protocol="0x2"/> </device> ``` As described in the README of the driver I added a configuration to `usb_modem_drv. Most of the times when I execute mbimcli.run (with or without a SIM card inserted) I get the following error: ``` Error: couldn't open the MbimDevice: Operation timed out: device is closed ``` On a low fraction of runs without SIM `mbimcli` reports that no sim is inserted. Setting the `TRACE` enum in `construct.cc` of mbimcli to `TRUE`, I see the following debug output. ``` [13:44:42.820] [init -> mbimcli] <<<<<< RAW: [13:44:42.821] [init -> mbimcli] <<<<<< length = 16 [13:44:42.821] [init -> mbimcli] <<<<<< data = 01:00:00:00:10:00:00:00:01:00:00:00:00:10:00:00 [13:44:42.842] [init -> mbimcli] [13:44:42.842] [init -> mbimcli] [Debug] [/dev/cdc-wdm0] Sent message (translated)... [13:44:42.843] [init -> mbimcli] <<<<<< Header: [13:44:42.843] [init -> mbimcli] <<<<<< length = 16 [13:44:42.843] [init -> mbimcli] <<<<<< type = open (0x00000001) [13:44:42.855] [init -> mbimcli] <<<<<< transaction = 1 [13:44:42.856] [init -> mbimcli] <<<<<< Contents: [13:44:42.856] [init -> mbimcli] <<<<<< max control transfer = 4096 [13:44:42.856] [init -> mbimcli] [13:44:47.821] [init -> mbimcli] [Debug] [/dev/cdc-wdm0] Sent message... [13:44:47.822] [init -> mbimcli] <<<<<< RAW: [13:44:47.822] [init -> mbimcli] <<<<<< length = 16 [13:44:47.822] [init -> mbimcli] <<<<<< data = 01:00:00:00:10:00:00:00:02:00:00:00:00:10:00:00 [13:44:47.844] [init -> mbimcli] [13:44:47.844] [init -> mbimcli] [Debug] [/dev/cdc-wdm0] Sent message (translated)... [13:44:47.845] [init -> mbimcli] <<<<<< Header: [13:44:47.845] [init -> mbimcli] <<<<<< length = 16 [13:44:47.845] [init -> mbimcli] <<<<<< type = open (0x00000001) [13:44:47.857] [init -> mbimcli] <<<<<< transaction = 2 [13:44:47.857] [init -> mbimcli] <<<<<< Contents: [13:44:47.857] [init -> mbimcli] <<<<<< max control transfer = 4096 [13:44:47.858] [init -> mbimcli] [13:44:50.890] [init -> mbimcli] [Debug] [/dev/cdc-wdm0] Received message... [13:44:50.891] [init -> mbimcli] >>>>>> RAW: [13:44:50.891] [init -> mbimcli] >>>>>> length = 16 [13:44:50.891] [init -> mbimcli] >>>>>> data = 01:00:00:80:10:00:00:00:01:00:00:00:00:00:00:00 [13:44:50.898] [init -> mbimcli] [13:44:50.899] [init -> mbimcli] [Debug] [/dev/cdc-wdm0] No transaction matched in received message [13:44:50.921] [init -> mbimcli] [Debug] [/dev/cdc-wdm0] Received unexpected message (translated)... [13:44:50.921] [init -> mbimcli] >>>>>> Header: [13:44:50.921] [init -> mbimcli] >>>>>> length = 16 [13:44:50.921] [init -> mbimcli] >>>>>> type = open-done (0x80000001) [13:44:50.936] [init -> mbimcli] >>>>>> transaction = 1 [13:44:50.936] [init -> mbimcli] >>>>>> Contents: [13:44:50.936] [init -> mbimcli] >>>>>> status error = 'None' (0x00000000) [13:44:50.936] [init -> mbimcli] [13:44:52.824] [init -> mbimcli] [Debug] [/dev/cdc-wdm0] Sent message... [13:44:52.825] [init -> mbimcli] <<<<<< RAW: [13:44:52.825] [init -> mbimcli] <<<<<< length = 16 [13:44:52.825] [init -> mbimcli] <<<<<< data = 01:00:00:00:10:00:00:00:03:00:00:00:00:10:00:00 [13:44:52.846] [init -> mbimcli] [13:44:52.846] [init -> mbimcli] [Debug] [/dev/cdc-wdm0] Sent message (translated)... [13:44:52.847] [init -> mbimcli] <<<<<< Header: [13:44:52.847] [init -> mbimcli] <<<<<< length = 16 [13:44:52.847] [init -> mbimcli] <<<<<< type = open (0x00000001) [13:44:52.859] [init -> mbimcli] <<<<<< transaction = 3 [13:44:52.859] [init -> mbimcli] <<<<<< Contents: [13:44:52.860] [init -> mbimcli] <<<<<< max control transfer = 4096 [13:44:52.860] [init -> mbimcli] ... ``` This looks to me, as if the device is too slow in answering the first request. `mbimcli` will continue to send until transaction ID nine is reached and then stop with the error message from above. Only one response is ever received per test run on error. When I insert a SIM card, then a second message is received directly after the first which looks as follows: ``` [15:24:15.668] [init -> mbimcli] [Debug] [/dev/cdc-wdm0] Received message... [15:24:15.668] [init -> mbimcli] >>>>>> RAW: [15:24:15.668] [init -> mbimcli] >>>>>> length = 92 [15:24:15.691] [init -> mbimcli] >>>>>> data = 07:00:00:80:5C:00:00:00:00:00:00:00:01:00:00:00:00:00:00:00:53:3F:BE:EB:14:FE:44:67:9F:90:33:A2:23:E5:6C:3F:01:00:00:00:30:00:00:00:01:00:00:00:00:00:00:00:35:00:00:00:00:00:00:00:18:00:00:00:18:00:00:00:2B:00:34: [15:24:15.691] [init -> mbimcli] 00:31:00:37:00:39:00:34:00:39:00:39:00:39:00:30:00:30:00:30:00 [15:24:15.691] [init -> mbimcli] [15:24:15.714] [init -> mbimcli] [Debug] [/dev/cdc-wdm0] Received message (translated)... [15:24:15.715] [init -> mbimcli] >>>>>> Header: [15:24:15.715] [init -> mbimcli] >>>>>> length = 92 [15:24:15.715] [init -> mbimcli] >>>>>> type = indicate-status (0x80000007) [15:24:15.736] [init -> mbimcli] >>>>>> transaction = 0 [15:24:15.736] [init -> mbimcli] >>>>>> Fragment header: [15:24:15.737] [init -> mbimcli] >>>>>> total = 1 [15:24:15.737] [init -> mbimcli] >>>>>> current = 0 [15:24:15.737] [init -> mbimcli] >>>>>> Contents: [15:24:15.753] [init -> mbimcli] >>>>>> service = 'sms' (533fbeeb-14fe-4467-9f90-33a223e56c3f) [15:24:15.753] [init -> mbimcli] >>>>>> cid = 'configuration' (0x00000001) [15:24:15.754] [init -> mbimcli] >>>>>> Fields: Unknown contents [15:24:15.754] [init -> mbimcli] ``` Still `mbimcli` will send further open requests. What I do not understand is that a service `sms` is reported, however the SIM in use doesn't support sending/receiving of SMS. In rare cases the following message also appears in the output: ``` [init -> usb_modem_drv] dev_err: nonzero urb status received: -EPIPE ``` I'm not sure if it is related, but as the modem is connected via USB it could be. The device is connected to a iMX8m mini, which uses the same `usb_host_drv` as the iMX6q sabrelite. Has anybody an idea how I could narrow down the issue? Best regards, Pirmin

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users November 2021