Lecroy Firmware downgrading...??? - Page 1
Forum section: electronics / testgear

author: darkstar49
author_rank: Frequent Contributor
timestamp: September 29, 2017, 07:59:33 am
content: Does anyone have informations about downgrading the firmware level of (X-Stream I & II) Lecroy scopes ??'heard rumors that Lecroy changed their options coding scheme recently... could that mean that options from recent versions (7.x, 8.x) would not be 'compatible' with older software versions (6.x or even older) ?? What would be the risk of downgrading the software ??And btw, if this is true, are the options being "re-encoded" during an s/w upgrade (I hope they're not lost !!) ?? Again, no clue as to what version is supposed to have brought that change, but if it's true, something would need to happen with the options, that is probably not "reversible"Any info/comment welcome...

author: robert_
author_rank: Regular Contributor
timestamp: September 29, 2017, 02:50:30 pm
content: I had absolutely no problem just installing an older FW package to downgrade from 8.x to 7.x. There seems to be no protection against that, at least there was none in 8.4.No options are lost going either way, at least everything that was there in 7.x will work fine after up/downgrading.If you do a clean reinstall etc. and need to re-enter old format option keys you have on paper etc, you need to install 7.x first to add those, then you can upgrade to 8.x again, the key conversion is done only during installation of 8.x. 8.x accepts old format keys but they dont work, unless you downgrade/re-upgrade to convert those to the new format. The old format keys stay there but are inactive.All based on a 64bit scope by the way. But 32bit scopes dont get the new releases anyway.I do not, however, know whether scopes shipped with 8.x will be able to run 7.x or older. Probably not, as these will not have the old format keys present. Also newly bought keys that come in new format only will not work on old firmware versions, sadly.

author: darkstar49
author_rank: Frequent Contributor
timestamp: September 29, 2017, 05:08:49 pm
content: interesting... btw, I heard that this was true for all 8.x versions, both 32- and 64bit...??Funny that one can enter old keys but that they'd remain inactive... and that a down/upgrade converts these...Anyway, thanks for the info !

author: robert_
author_rank: Regular Contributor
timestamp: September 29, 2017, 05:21:11 pm
content: Quote from: darkstar49 on September 29, 2017, 05:08:49 pmI dont know much about the 32bit scopes and their firmware status as i never had one. I previously thought 32bit scopes never got above 7.x but it seems that some do, some not. Oh well.Yes, looks like they forgot to disable to accept old keys. Or, if they want to stay user friendly, invoke the conversion after entering one and not only during installation.Still, as a simple down/upgrade cycle does the trick, at least right now, everything should be fine.

author: DaJMasta
author_rank: Super Contributor
timestamp: September 29, 2017, 06:18:29 pm
content: I don't know much about the specific query, but there are 32 bit versions of X-Stream that go to at least 8.1. I've got a WavePro 7200 and my limitation is 6.1.4 (if I remember right) because it's running Windows 2000, but if it were running Windows XP (I don't think with the x64 requirement, just my same 32 bit hardware) I can get up to 8.1, though to get the drivers for the interface board the 6.1 version needs to be installed first.I would assume there's no problem downgrading with a full wipe/removal of the original, but there's always the risk of residual files and things if you're just uninstalling the new and reinstalling the old. I don't know for sure where the option keys are stored in my scope (perhaps in the partition with the cal data?), but I can confirm that they're not being read from the acquisition board, at least in my unit, and that scopes of the same vintage and 32 bit architecture can get some of the newer X-Stream software versions, provided they have an older version with suitable drivers installed first.

author: robert_
author_rank: Regular Contributor
timestamp: September 29, 2017, 06:57:48 pm
content: Quote from: DaJMasta on September 29, 2017, 06:18:29 pmCould be, but i have seen no problems with going from 8.4 to 7.9 by just running the 7.9 installer file, nothing else.64bit win7 system here.

author: darkstar49
author_rank: Frequent Contributor
timestamp: September 29, 2017, 07:09:22 pm
content: option keys are (always !) stored on the acquisition board (or eventually on the interface board to it), so even if you change the hard disk, the keys are kept...Regarding X-Stream I scopes, yes, the acquisition board drivers exist only in 32-bit versions, and even worse, these drivers have more or less serious issues with multi-core kernel versions (of XP), X-Stream II scopes (even 32bit) are the only ones for which the drivers support multi-cores.And yes, be it for X-Stream I or II, the latest version of the 32bit software is currently 8.1.0.1.Should be confirmed, but your WP7K should be compatible with that version... although not officially supported by Lecroy. Just upgrade to XP first... I've got a WR6K in 7.x, no issue whatsoever... the only issue is indeed that X-Stream I drivers are no longer included in the installation package since some 7.x version, so you need to install some 6.x and upgrade afterwards...So this is in fact the main reason of my question... hard disks fail, disks get corrupted, so a re-install from scratch is not that unusual, and I was wondering if this happens when one has 8.x installed, and you need to start over with some 6.x (to have the correct drivers), what would happen to the (apparently) previously up-converted option keys...Strange btw that Lecroy changed that recently... as it was to my knowledge one of the few, if not the only scope maker from which the option keys stuff had not (yet) been cracked... (there are enough threads for other brands on this forum... ;-)

author: lukier
author_rank: Unknown
timestamp: September 29, 2017, 09:11:46 pm
content: Quote from: darkstar49 on September 29, 2017, 07:09:22 pmIn WaveRunner 6KA the options are stored on a 1-Wire EEPROM on the PCI aqusition card surprisingly, not on the FLASH on the main scope PCB. Seems strange, if the card needs replacing for whatever reasons you loose all the options. Don't know about other LeCroy scopes.Quote from: darkstar49 on September 29, 2017, 07:09:22 pmYup. Not only WavePro7K drivers have issues. Driver for the WaveRunner 6KA (LecS65AcqDrv.sys) also has some bugs on newer chipsets/CPUs (i7 Haswell) when using PCIe to PCI adapters. I suspect some missing critical sections in the driver in something related to the interrupts (that are often shared in PCIe). Technically the scope works, but in practice there are multiple glitches and timeout errors, so I downgraded to Core2Quad Q9400 platformQuote from: darkstar49 on September 29, 2017, 07:09:22 pmI'm running 8.4.1.4 on WaveRunner 6100A. Windows7 x32, installed 6.x first and then latest x32 X-Stream I could find on LeCroy's website. Seems fine.Quote from: darkstar49 on September 29, 2017, 07:09:22 pmI guess nothing will happen (well no warranty), but I don't use 6.x, just install it for the drivers and immediately install 8.x over that. I've been experimenting a lot with different motherboards, multiple OS installs and so on, when I was modding and experimenting with my scope. I only cared about the calibration files, as these are super-critical.See some details here:https://www.eevblog.com/forum/testgear/upgrading-mainboard-in-lecroy-dda-3000-(aka-wavepro-7300a)/msg1282724/#msg1282724

author: darkstar49
author_rank: Frequent Contributor
timestamp: September 30, 2017, 01:47:39 pm
content: not very clear (for me) so far... if the keys get converted to a new format (/encryption or whatsoever) during an upgrade with a recent version, and for whatever reason you need to reinstall (for example, from scratch with a new disk), with a 6.x (or early 7.x) version (because of the drivers)...1) will the 6.x/7.x version keep "new-format" keys untouched in the key-store ?2) will the (re)upgrade to 8.x know that these keys had already been converted before? (otherwise, these will most likely become totally scrambled !!)

author: DaJMasta
author_rank: Super Contributor
timestamp: September 30, 2017, 03:27:20 pm
content: My assumption is that whatever algorithm they use to 'update' the keys will only work on the old format ones, otherwise every software update that supports updating from the pre-new-key version of the software would change the keys, so there would have probably already been a fiasco about issues when upgrading.I wouldn't be surprised that if you wiped the OS and reinstalled an older set of drivers that the keys would no longer work until you upgraded to the software version that supports the new key style. The X-Stream software lets you view/add the keys though, so can't you take a screenshot and later reinput them if anything were to happen? Since the keys are also likely tied to the serial number of the instrument, LeCroy probably has records of them being purchased, and there's a chance they'd be able to help in a possible recovery as well.

author: darkstar49
author_rank: Frequent Contributor
timestamp: September 30, 2017, 05:13:27 pm
content: well... that's what it's all about... ;-)But if Lecroy uses some 'standard' crypto routine, there's little chance they can tell upfront whether the key is old-style or new-style, unless1) the encrypted key format has changed (i.e. no longer the 'old' xxxx-xxxx-xxxx-xxxx format)2) the scope maintains a 'flag' in the keystore to know whether or not a particular key has been migrated/converted...There's no miracle... yes, keys are somehow tied to the serial, and no, with these short keys, and assuming the format has not changed ('would be interesting to have an 8.x key, btw !!), I doubt there's a way to 'recognise' whether a given key is 'old-style' or not...Typically, the scope will decode a key (from user input or from the store), and if there's no match with the serial (at least), the key will be considered invalid/void...Would be interesting to have some feedback from Lecroy on this...And about some 'central' keys repository at Lecroy... I'm not too sure... by far not all companies do that, but it's indeed a possible option...

author: abraxa
author_rank: Frequent Contributor
timestamp: October 14, 2017, 09:06:00 pm
content: Quote from: darkstar49 on September 30, 2017, 05:13:27 pmThey have it and can dig up the purchased options for any scope, given its serial number. Probably makes for interesting conversations when certain units come in for repair.

author: darkstar49
author_rank: Frequent Contributor
timestamp: October 15, 2017, 07:15:23 pm
content: Quote from: abraxa on October 14, 2017, 09:06:00 pmwell... this supposes 2 things: the scope was hacked (/upgraded with rogue keys) and the user is not aware of this...Lecroy is by far not as much hacked as Keysight and Tek, and given the possibilities of the service mode (... cf other thread...), one would be stupid to send in a scope with rogue keys indeed... clear those first, send in, and re-install the keys afterwards will probably avoid those (not so funny) discussions...

author: nctnico
author_rank: Super Contributor
timestamp: October 15, 2017, 08:50:45 pm
content: Quote from: abraxa on October 14, 2017, 09:06:00 pmI don't think so. If they make a fuss about then there are several competitors which are very pleased to take the customer's money instead.

author: bson
author_rank: Unknown
timestamp: October 15, 2017, 10:35:46 pm
content: Quote from: abraxa on October 14, 2017, 09:06:00 pmOnly LeCroy generates option licenses, so when you buy one you buy it from them, and they definitely keep track of what they've sold. They have to, at least for tax purposes...What they may not have is a per-unit private key registry and use RSA for the license generation; more likely than not there's merely a model specific shared secret that combined with a salt, serial, and some fixed sequence(s) to generate a digest (signature) and a portion of that constitutes the license. The shared secret is stashed in an FPGA or a microcontroller with fused onboard flash, hence why the licenses would be stored someplace easily accessible for the acquisition hardware - it's simply the most convenient spot to validate them while keeping the secret, well, secret.I'm pretty sure when you replace a board with options X Y Z enabled they send you back a blank board and email you license keys for X Y Z, and may even preinstall them for you (not sure).

author: lukier
author_rank: Unknown
timestamp: October 15, 2017, 11:17:41 pm
content: Well you can see here how the keys are installed in the factory:https://youtu.be/xUTD3Tku8UY?t=509Contacting some LeCroy server named CN=GENEVA_NTS/O=LECROY, so I guess they must have such records.Quote from: bson on October 15, 2017, 10:35:46 pmAre you sure this is how this works? Maybe for X-Stream II, but definitely not for the older scopes.

author: darkstar49
author_rank: Frequent Contributor
timestamp: October 16, 2017, 04:24:47 am
content: This is drifting pretty far away from the (original) subject... i.e. about the possibility to downgrade an 8.x firmware without losing the keys, and/or the fact that the key generation scheme changed with version 8.x (or some late 7.x)...

author: w2hx
author_rank: Contributor
timestamp: April 25, 2020, 06:54:19 pm
content: Does anyone here have a pre-8.0 version of the firmware for the WaveRunner 6Zi series? I am looking to downgrade as per the topic.Thanks