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Both the Wifi driver and the WireGuard port used local implementations for their source of randomness. Wifi used a Xoroshiro128+ PRNG for rapid generation of random values but initialized this PRNG always with the same static seed value. WireGuard, in contrast, requested each random byte directly from the jitterentropy lib, which is considered to be very time intensive. This commit removes the local variants of random.cc and introduces a new centralized lx_emul/random.cc . The new variant combines the former approaches, so, that jitterentropy is accessed only in order to generate a random seed for a Xoroshiro128+ PRNG. Front-end requests for random values are then fulfilled efficiently via the PRNG. :Warning: The output of the Xoroshiro128+ PRNG that is used in the new implementation of the lx_emul randomness functions has known statistical problems (see https://en.wikipedia.org/wiki/Xoroshiro128%2B#Statistical_Quality). Furthermore, the integration of Xoroshir128+ with the lx_emul code was not reviewed/audited for its security-related properties, so far, and has the known deficiency of seeding the PRNG only once during initialization. Thus, we strongly advise against the use of the lx_emul randomness functions for security-critical purposes. Ref #4397 |
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| fec.list | ||
| lxip.list | ||
| README | ||
| usb_hid.list | ||
| usb_host.list | ||
| usb_modem.list | ||
| usb_net.list | ||
| usb.list | ||
Device drivers ported from the Linux kernel USB ### Host controller ~~~~~~~~~~~~~~~ The driver will start all USB controller types a platform offers. Please consult repos/dde_linux/drivers/usb_host/README for a description. HID ~~~ Please consult repos/dde_linux/drivers/usb_hid/README for a description. Storage ~~~~~~~ Please consult repos/os/src/drivers/usb_block/README for a description. Network (Nic) ~~~~~~~~~~~~~ Please consolut repos/dde_linux/src/drivers/usb_net/README for a description. LXIP #### LXIP is a port of the Linux TCP/IP stack to Genode. It is build as a shared library named 'lxip.lib.so'. The IP stack can be interfaced using Genode's version of 'libc' by linking your application to 'lxip_libc' plugin in your 'target.mk' file. lx_kit ###### The modular lx_kit seperates the required back end functionality of the Linux emulation environment from the front end. Thereby each driver can reuse specific parts or supply more suitable implementations by itself. It is used to reduce the amount of redundant code in each driver. The lx_kit is split into several layers whose structure is as follows: The first layer in _repos/dde_linux/src/include/lx_emul_ contains those header files that provide the structural definitions and function declarations of the Linux API, e.g. _errno.h_ provides all error code values. The second layer in _repos/dde_linux/src/include/lx_emul/impl_ contains the implementation of selected functions, e.g. _slab.h_ provides the implementation of 'kmalloc()'. The lx_kit back end API is the third layer and provides the _Lx::Malloc_ interface (_repos/dde_linux/src/include/lx_kit/malloc.h_) which is used to implement 'kmalloc()'. There are several generic implementations of the lx_kit interfaces that can be used by a driver. A driver typically includes a 'lx_emul/impl/xyz.h' header once directly in its lx_emul compilation unit. The lx_kit interface files are only included in those compilation units that use or implement the interface. If a driver wants to use a generic implementation it must add the source file to its source file list. The generic implementations are located in _repos/dde_linux/src/lx_kit/_. The modular lx_kit still depends on the private _lx_emul.h_ header file that is tailored to each driver. Since the lx_kit already contains much of the declarations and definitions that were originally placed in these private header files, those files can now ommit a large amount of code.