| Message ID | 1525857024-14483-1-git-send-email-ppaidipe@linux.vnet.ibm.com |
|---|---|
| State | Rejected |
| Headers | show |
| Series | libstb/secureboot: Disable secureboot in OPAL by nvram | expand |
On 05/09/2018 02:40 PM, Pridhiviraj Paidipeddi wrote: > Currently custom debug petitboot kernels failed to boot on secureboot > enabled systems as the key verification fails results in enforcing the > boot. Due to which debugging any problems in petitboot kernel in secure > boot enabled systems become hard. > This patch provides a way to disable secureboot in OPAL by using below > nvram command. Petitboot verification should not be disabled if firmware secure boot is on. Its only Host OS kernel for which we can have the switch. This patch can result in a loophole where someone as application user can disable verification of petitboot kernel using nvram utility. Thanks & Regards, - Nayna > nvram -p ibm,skiboot --update-config force-secure-mode=false > > Signed-off-by: Pridhiviraj Paidipeddi <ppaidipe@linux.vnet.ibm.com> > --- > libstb/secureboot.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/libstb/secureboot.c b/libstb/secureboot.c > index 348acf5..8c8a9d6 100644 > --- a/libstb/secureboot.c > +++ b/libstb/secureboot.c > @@ -107,6 +107,9 @@ void secureboot_init(void) > if (nvram_query_eq("force-secure-mode", "always")) { > secure_mode = true; > prlog(PR_NOTICE, "secure mode on (FORCED by nvram)\n"); > + } else if (nvram_query_eq("force-secure-mode", "false")) { > + secure_mode = false; > + prlog(PR_NOTICE, "secure mode off (FORCED by nvram)\n"); > } else { > secure_mode = dt_has_node_property(node, "secure-enabled", NULL); > prlog(PR_NOTICE, "secure mode %s\n",
On 2018-05-11 16:52, Nayna Jain wrote: > On 05/09/2018 02:40 PM, Pridhiviraj Paidipeddi wrote: >> Currently custom debug petitboot kernels failed to boot on secureboot >> enabled systems as the key verification fails results in enforcing the >> boot. Due to which debugging any problems in petitboot kernel in >> secure >> boot enabled systems become hard. >> This patch provides a way to disable secureboot in OPAL by using below >> nvram command. > > Petitboot verification should not be disabled if firmware secure boot > is on. Its only Host OS kernel > for which we can have the switch. > > This patch can result in a loophole where someone as application user > can disable > verification of petitboot kernel using nvram utility. Yeah, agree, but this is really a debug hack, without that there are bugs related to keys in upstream vs vendor released firmware, due to which verification fails and boot enforce happening on secureboot enabled systems, so we need a way to force disable it, like the way we have for enabling it via nvram. Otherwise debugging petitboot kernels on such systems became really hard. Thanks Pridhiviraj > > Thanks & Regards, > - Nayna > >> nvram -p ibm,skiboot --update-config force-secure-mode=false >> >> Signed-off-by: Pridhiviraj Paidipeddi <ppaidipe@linux.vnet.ibm.com> >> --- >> libstb/secureboot.c | 3 +++ >> 1 file changed, 3 insertions(+) >> >> diff --git a/libstb/secureboot.c b/libstb/secureboot.c >> index 348acf5..8c8a9d6 100644 >> --- a/libstb/secureboot.c >> +++ b/libstb/secureboot.c >> @@ -107,6 +107,9 @@ void secureboot_init(void) >> if (nvram_query_eq("force-secure-mode", "always")) { >> secure_mode = true; >> prlog(PR_NOTICE, "secure mode on (FORCED by nvram)\n"); >> + } else if (nvram_query_eq("force-secure-mode", "false")) { >> + secure_mode = false; >> + prlog(PR_NOTICE, "secure mode off (FORCED by nvram)\n"); >> } else { >> secure_mode = dt_has_node_property(node, "secure-enabled", NULL); >> prlog(PR_NOTICE, "secure mode %s\n",
<div class="socmaildefaultfont" dir="ltr" style="font-family:Arial, Helvetica, sans-serif;font-size:10.5pt" ><div dir="ltr" > </div>
<div dir="ltr" ><div class="socmaildefaultfont" dir="ltr" style="font-family:Arial, Helvetica, sans-serif;font-size:10.5pt" ><div class="socmaildefaultfont" dir="ltr" style="font-family:Arial, Helvetica, sans-serif;font-size:10.5pt" ><div class="socmaildefaultfont" dir="ltr" style="font-family:Arial, Helvetica, sans-serif;font-size:10.5pt" ><div class="socmaildefaultfont" dir="ltr" style="font-family:Arial, Helvetica, sans-serif;font-size:10.5pt" ><div class="socmaildefaultfont" dir="ltr" style="font-family:Arial;font-size:10.5pt" ><div dir="ltr" ><div><font size="2" face="Default Sans Serif,Verdana,Arial,Helvetica,sans-serif" >---</font></div>
<div><font size="2" face="Default Sans Serif,Verdana,Arial,Helvetica,sans-serif" >Claudio Carvalho</font></div>
<div><font size="2" face="Default Sans Serif,Verdana,Arial,Helvetica,sans-serif" >Linux Security Development - IBM LTC</font></div></div></div></div></div></div></div></div>
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<blockquote data-history-content-modified="1" data-history-expanded="1" dir="ltr" style="border-left:solid #aaaaaa 2px; margin-left:5px; padding-left:5px; direction:ltr; margin-right:0px" >----- Original message -----<br>From: ppaidipe <ppaidipe@linux.vnet.ibm.com><br>To: Nayna Jain <nayna@linux.vnet.ibm.com><br>Cc: skiboot@lists.ozlabs.org, George Wilson <gcwilson@us.ibm.com>, Claudio Carvalho/Brazil/IBM@IBMBR, hellerda@us.ibm.com, erichte@us.ibm.com, sarahw@us.ibm.com<br>Subject: Re: [Skiboot] [PATCH] libstb/secureboot: Disable secureboot in OPAL by nvram<br>Date: Fri, May 11, 2018 9:04 AM<br>
<div><font size="2" face="Default Monospace,Courier New,Courier,monospace" >On 2018-05-11 16:52, Nayna Jain wrote:<br>> On 05/09/2018 02:40 PM, Pridhiviraj Paidipeddi wrote:<br>>> Currently custom debug petitboot kernels failed to boot on secureboot<br>>> enabled systems as the key verification fails results in enforcing the<br>>> boot. Due to which debugging any problems in petitboot kernel in<br>>> secure<br>>> boot enabled systems become hard.<br>>> This patch provides a way to disable secureboot in OPAL by using below<br>>> nvram command.<br>><br>> Petitboot verification should not be disabled if firmware secure boot<br>> is on. Its only Host OS kernel<br>> for which we can have the switch.<br>><br>> This patch can result in a loophole where someone as application user<br>> can disable<br>> verification of petitboot kernel using nvram utility.<br><br>Yeah, agree, but this is really a debug hack, without that there are<br>bugs related to keys<br>in upstream vs vendor released firmware, due to which verification fails<br>and boot enforce<br>happening on secureboot enabled systems,</font></div>
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<div dir="ltr" >I'm not sure if I know what bug you are talking about here. Can you elaborate more on that?</div>
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<div dir="ltr" >Thanks,</div>
<div dir="ltr" >Claudio</div>
<div dir="ltr" > </div>
<blockquote class="history-quote-1526040784418" data-history-content-modified="1" data-history-expanded="1" dir="ltr" style="border-left:solid #aaaaaa 2px; margin-left:5px; padding-left:5px; direction:ltr; margin-right:0px" ><div><font size="2" face="Default Monospace,Courier New,Courier,monospace" >so we need a way to force<br>disable it, like the way<br>we have for enabling it via nvram. Otherwise debugging petitboot kernels<br>on such systems<br>became really hard.<br><br>Thanks<br>Pridhiviraj<br><br>><br>> Thanks & Regards,<br>> - Nayna<br>><br>>> nvram -p ibm,skiboot --update-config force-secure-mode=false<br>>><br>>> Signed-off-by: Pridhiviraj Paidipeddi <ppaidipe@linux.vnet.ibm.com><br>>> ---<br>>> libstb/secureboot.c | 3 +++<br>>> 1 file changed, 3 insertions(+)<br>>><br>>> diff --git a/libstb/secureboot.c b/libstb/secureboot.c<br>>> index 348acf5..8c8a9d6 100644<br>>> --- a/libstb/secureboot.c<br>>> +++ b/libstb/secureboot.c<br>>> @@ -107,6 +107,9 @@ void secureboot_init(void)<br>>> if (nvram_query_eq("force-secure-mode", "always")) {<br>>> secure_mode = true;<br>>> prlog(PR_NOTICE, "secure mode on (FORCED by nvram)\n");<br>>> + } else if (nvram_query_eq("force-secure-mode", "false")) {<br>>> + secure_mode = false;<br>>> + prlog(PR_NOTICE, "secure mode off (FORCED by nvram)\n");<br>>> } else {<br>>> secure_mode = dt_has_node_property(node, "secure-enabled", NULL);<br>>> prlog(PR_NOTICE, "secure mode %s\n",</font></div></blockquote>
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On 2018-05-11 17:47, Claudio Carvalho wrote: > --- > Claudio Carvalho > Linux Security Development - IBM LTC > >> ----- Original message ----- >> From: ppaidipe <ppaidipe@linux.vnet.ibm.com> >> To: Nayna Jain <nayna@linux.vnet.ibm.com> >> Cc: skiboot@lists.ozlabs.org, George Wilson <gcwilson@us.ibm.com>, >> Claudio Carvalho/Brazil/IBM@IBMBR, hellerda@us.ibm.com, >> erichte@us.ibm.com, sarahw@us.ibm.com >> Subject: Re: [Skiboot] [PATCH] libstb/secureboot: Disable secureboot >> in OPAL by nvram >> Date: Fri, May 11, 2018 9:04 AM >> >> On 2018-05-11 16:52, Nayna Jain wrote: >>> On 05/09/2018 02:40 PM, Pridhiviraj Paidipeddi wrote: >>>> Currently custom debug petitboot kernels failed to boot on >> secureboot >>>> enabled systems as the key verification fails results in >> enforcing the >>>> boot. Due to which debugging any problems in petitboot kernel in >>>> secure >>>> boot enabled systems become hard. >>>> This patch provides a way to disable secureboot in OPAL by using >> below >>>> nvram command. >>> >>> Petitboot verification should not be disabled if firmware secure >> boot >>> is on. Its only Host OS kernel >>> for which we can have the switch. >>> >>> This patch can result in a loophole where someone as application >> user >>> can disable >>> verification of petitboot kernel using nvram utility. >> >> Yeah, agree, but this is really a debug hack, without that there are >> bugs related to keys >> in upstream vs vendor released firmware, due to which verification >> fails >> and boot enforce >> happening on secureboot enabled systems, > > I'm not sure if I know what bug you are talking about here. Can you > elaborate more on that? Yes, Lets say p9dsu system is having latest supermicro released firmware(having imprint keys) and secureboot mode is enabled in the system. If we compile custom kernel in upstream op-build using development mode in signed mode and flash that on that failed secureboot system. so when we boot with that kernel, keys verification is failing, i am not sure why it is failing now, earlier it works when doing testing. The kernel tried from both the places one is zImage.epapr and another one is extracted BOOTKERNEL partition from full PNOR built in signed imprint mode. Using both the images verification is failing now. > > Thanks, > Claudio > >> so we need a way to force >> disable it, like the way >> we have for enabling it via nvram. Otherwise debugging petitboot >> kernels >> on such systems >> became really hard. >> >> Thanks >> Pridhiviraj >> >>> >>> Thanks & Regards, >>> - Nayna >>>
On 11/05/2018 09:33, ppaidipe wrote: > On 2018-05-11 17:47, Claudio Carvalho wrote: >> --- >> Claudio Carvalho >> Linux Security Development - IBM LTC >> >>> ----- Original message ----- >>> From: ppaidipe <ppaidipe@linux.vnet.ibm.com> >>> To: Nayna Jain <nayna@linux.vnet.ibm.com> >>> Cc: skiboot@lists.ozlabs.org, George Wilson <gcwilson@us.ibm.com>, >>> Claudio Carvalho/Brazil/IBM@IBMBR, hellerda@us.ibm.com, >>> erichte@us.ibm.com, sarahw@us.ibm.com >>> Subject: Re: [Skiboot] [PATCH] libstb/secureboot: Disable secureboot >>> in OPAL by nvram >>> Date: Fri, May 11, 2018 9:04 AM >>> >>> On 2018-05-11 16:52, Nayna Jain wrote: >>>> On 05/09/2018 02:40 PM, Pridhiviraj Paidipeddi wrote: >>>>> Currently custom debug petitboot kernels failed to boot on >>> secureboot >>>>> enabled systems as the key verification fails results in >>> enforcing the >>>>> boot. Due to which debugging any problems in petitboot kernel in >>>>> secure >>>>> boot enabled systems become hard. >>>>> This patch provides a way to disable secureboot in OPAL by using >>> below >>>>> nvram command. >>>> >>>> Petitboot verification should not be disabled if firmware secure >>> boot >>>> is on. Its only Host OS kernel >>>> for which we can have the switch. >>>> >>>> This patch can result in a loophole where someone as application >>> user >>>> can disable >>>> verification of petitboot kernel using nvram utility. >>> >>> Yeah, agree, but this is really a debug hack, without that there are >>> bugs related to keys >>> in upstream vs vendor released firmware, due to which verification >>> fails >>> and boot enforce >>> happening on secureboot enabled systems, >> >> I'm not sure if I know what bug you are talking about here. Can you >> elaborate more on that? > > Yes, Lets say p9dsu system is having latest supermicro released > firmware(having imprint keys) > and secureboot mode is enabled in the system. If we compile custom > kernel in upstream op-build > using development mode in signed mode and flash that on that failed > secureboot system. so when > we boot with that kernel, keys verification is failing, i am not sure > why it is failing now, earlier > it works when doing testing. The kernel tried from both the places one > is zImage.epapr and another > one is extracted BOOTKERNEL partition from full PNOR built in signed > imprint mode. Using both the images > verification is failing now. Hmm ... as long as the system trusts the imprinting keys (not any production key), you should still be able to build and boot custom zImage.epapr signed with imprinting keys. Do you remember how you built (and signed) the zImage.epapr? Claudio > >> >> Thanks, >> Claudio >> >>> so we need a way to force >>> disable it, like the way >>> we have for enabling it via nvram. Otherwise debugging petitboot >>> kernels >>> on such systems >>> became really hard. >>> >>> Thanks >>> Pridhiviraj >>> >>>> >>>> Thanks & Regards, >>>> - Nayna >>>> > > _______________________________________________ > Skiboot mailing list > Skiboot@lists.ozlabs.org > https://lists.ozlabs.org/listinfo/skiboot
On 2018-05-11 18:24, Claudio Carvalho wrote: > On 11/05/2018 09:33, ppaidipe wrote: >> On 2018-05-11 17:47, Claudio Carvalho wrote: >>> --- >>> Claudio Carvalho >>> Linux Security Development - IBM LTC >>> >>>> ----- Original message ----- >>>> From: ppaidipe <ppaidipe@linux.vnet.ibm.com> >>>> To: Nayna Jain <nayna@linux.vnet.ibm.com> >>>> Cc: skiboot@lists.ozlabs.org, George Wilson <gcwilson@us.ibm.com>, >>>> Claudio Carvalho/Brazil/IBM@IBMBR, hellerda@us.ibm.com, >>>> erichte@us.ibm.com, sarahw@us.ibm.com >>>> Subject: Re: [Skiboot] [PATCH] libstb/secureboot: Disable secureboot >>>> in OPAL by nvram >>>> Date: Fri, May 11, 2018 9:04 AM >>>> >>>> On 2018-05-11 16:52, Nayna Jain wrote: >>>>> On 05/09/2018 02:40 PM, Pridhiviraj Paidipeddi wrote: >>>>>> Currently custom debug petitboot kernels failed to boot on >>>> secureboot >>>>>> enabled systems as the key verification fails results in >>>> enforcing the >>>>>> boot. Due to which debugging any problems in petitboot kernel in >>>>>> secure >>>>>> boot enabled systems become hard. >>>>>> This patch provides a way to disable secureboot in OPAL by using >>>> below >>>>>> nvram command. >>>>> >>>>> Petitboot verification should not be disabled if firmware secure >>>> boot >>>>> is on. Its only Host OS kernel >>>>> for which we can have the switch. >>>>> >>>>> This patch can result in a loophole where someone as application >>>> user >>>>> can disable >>>>> verification of petitboot kernel using nvram utility. >>>> >>>> Yeah, agree, but this is really a debug hack, without that there are >>>> bugs related to keys >>>> in upstream vs vendor released firmware, due to which verification >>>> fails >>>> and boot enforce >>>> happening on secureboot enabled systems, >>> >>> I'm not sure if I know what bug you are talking about here. Can you >>> elaborate more on that? >> >> Yes, Lets say p9dsu system is having latest supermicro released >> firmware(having imprint keys) >> and secureboot mode is enabled in the system. If we compile custom >> kernel in upstream op-build >> using development mode in signed mode and flash that on that failed >> secureboot system. so when >> we boot with that kernel, keys verification is failing, i am not sure >> why it is failing now, earlier >> it works when doing testing. The kernel tried from both the places one >> is zImage.epapr and another >> one is extracted BOOTKERNEL partition from full PNOR built in signed >> imprint mode. Using both the images >> verification is failing now. > > Hmm ... as long as the system trusts the imprinting keys (not any > production key), you should still be able to build and boot custom > zImage.epapr signed with imprinting keys. Do you remember how you > built (and signed) the zImage.epapr? > Yeah, on current upstream op-build, add this patch https://github.com/open-power/op-build/pull/1988 to enable secureboot and build signed imprint PNOR, before build we will add some custom patches to linux in openpower/linux folder and then do full op-build. Then try to flash the BOOTKERNEL which is extracted from full PNOR image built, then we will hit it. Thanks Pridhiviraj > Claudio > >> >>> >>> Thanks, >>> Claudio >>> >>>> so we need a way to force >>>> disable it, like the way >>>> we have for enabling it via nvram. Otherwise debugging petitboot >>>> kernels >>>> on such systems >>>> became really hard. >>>> >>>> Thanks >>>> Pridhiviraj >>>> >>>>> >>>>> Thanks & Regards, >>>>> - Nayna >>>>> >> >> _______________________________________________ >> Skiboot mailing list >> Skiboot@lists.ozlabs.org >> https://lists.ozlabs.org/listinfo/skiboot
On 5/11/2018 9:09 AM, ppaidipe wrote: > On 2018-05-11 18:24, Claudio Carvalho wrote: >> On 11/05/2018 09:33, ppaidipe wrote: >>> On 2018-05-11 17:47, Claudio Carvalho wrote: >>>> --- >>>> Claudio Carvalho >>>> Linux Security Development - IBM LTC >>>> >>>>> ----- Original message ----- >>>>> From: ppaidipe <ppaidipe@linux.vnet.ibm.com> >>>>> To: Nayna Jain <nayna@linux.vnet.ibm.com> >>>>> Cc: skiboot@lists.ozlabs.org, George Wilson <gcwilson@us.ibm.com>, >>>>> Claudio Carvalho/Brazil/IBM@IBMBR, hellerda@us.ibm.com, >>>>> erichte@us.ibm.com, sarahw@us.ibm.com >>>>> Subject: Re: [Skiboot] [PATCH] libstb/secureboot: Disable secureboot >>>>> in OPAL by nvram >>>>> Date: Fri, May 11, 2018 9:04 AM >>>>> >>>>> On 2018-05-11 16:52, Nayna Jain wrote: >>>>>> On 05/09/2018 02:40 PM, Pridhiviraj Paidipeddi wrote: >>>>>>> Currently custom debug petitboot kernels failed to boot on >>>>> secureboot >>>>>>> enabled systems as the key verification fails results in >>>>> enforcing the >>>>>>> boot. Due to which debugging any problems in petitboot kernel in >>>>>>> secure >>>>>>> boot enabled systems become hard. >>>>>>> This patch provides a way to disable secureboot in OPAL by using >>>>> below >>>>>>> nvram command. >>>>>> >>>>>> Petitboot verification should not be disabled if firmware secure >>>>> boot >>>>>> is on. Its only Host OS kernel >>>>>> for which we can have the switch. >>>>>> >>>>>> This patch can result in a loophole where someone as application >>>>> user >>>>>> can disable >>>>>> verification of petitboot kernel using nvram utility. >>>>> >>>>> Yeah, agree, but this is really a debug hack, without that there are >>>>> bugs related to keys >>>>> in upstream vs vendor released firmware, due to which verification >>>>> fails >>>>> and boot enforce >>>>> happening on secureboot enabled systems, >>>> >>>> I'm not sure if I know what bug you are talking about here. Can you >>>> elaborate more on that? >>> >>> Yes, Lets say p9dsu system is having latest supermicro released >>> firmware(having imprint keys) >>> and secureboot mode is enabled in the system. If we compile custom >>> kernel in upstream op-build >>> using development mode in signed mode and flash that on that failed >>> secureboot system. so when >>> we boot with that kernel, keys verification is failing, i am not sure >>> why it is failing now, earlier >>> it works when doing testing. The kernel tried from both the places >>> one is zImage.epapr and another >>> one is extracted BOOTKERNEL partition from full PNOR built in signed >>> imprint mode. Using both the images >>> verification is failing now. >> >> Hmm ... as long as the system trusts the imprinting keys (not any >> production key), you should still be able to build and boot custom >> zImage.epapr signed with imprinting keys. Do you remember how you >> built (and signed) the zImage.epapr? >> > > Yeah, on current upstream op-build, add this patch > https://github.com/open-power/op-build/pull/1988 to enable > secureboot and build signed imprint PNOR, before build we will add some > custom patches to linux in openpower/linux folder > and then do full op-build. Then try to flash the BOOTKERNEL which is > extracted from full PNOR image built, then we > will hit it. > Does this happen if you flash the full PNOR image or only if try to flash the partition individually? If just the latter, maybe the partition reflash does not work exactly as we expect. Claudio, correct me if I'm wrong but I think flashing the zImage.epapr will not work here because that is not a complete, signed container; it is only the payload. > Thanks > Pridhiviraj > >> Claudio >> >>> >>>> >>>> Thanks, >>>> Claudio >>>> >>>>> so we need a way to force >>>>> disable it, like the way >>>>> we have for enabling it via nvram. Otherwise debugging petitboot >>>>> kernels >>>>> on such systems >>>>> became really hard. >>>>> >>>>> Thanks >>>>> Pridhiviraj >>>>> >>>>>> >>>>>> Thanks & Regards, >>>>>> - Nayna >>>>>> >>> >>> _______________________________________________ >>> Skiboot mailing list >>> Skiboot@lists.ozlabs.org >>> https://lists.ozlabs.org/listinfo/skiboot
On 2018-05-11 18:49, hellerda wrote: > On 5/11/2018 9:09 AM, ppaidipe wrote: >> On 2018-05-11 18:24, Claudio Carvalho wrote: >>> On 11/05/2018 09:33, ppaidipe wrote: >>>> On 2018-05-11 17:47, Claudio Carvalho wrote: >>>>> --- >>>>> Claudio Carvalho >>>>> Linux Security Development - IBM LTC >>>>> >>>>>> ----- Original message ----- >>>>>> From: ppaidipe <ppaidipe@linux.vnet.ibm.com> >>>>>> To: Nayna Jain <nayna@linux.vnet.ibm.com> >>>>>> Cc: skiboot@lists.ozlabs.org, George Wilson <gcwilson@us.ibm.com>, >>>>>> Claudio Carvalho/Brazil/IBM@IBMBR, hellerda@us.ibm.com, >>>>>> erichte@us.ibm.com, sarahw@us.ibm.com >>>>>> Subject: Re: [Skiboot] [PATCH] libstb/secureboot: Disable >>>>>> secureboot >>>>>> in OPAL by nvram >>>>>> Date: Fri, May 11, 2018 9:04 AM >>>>>> >>>>>> On 2018-05-11 16:52, Nayna Jain wrote: >>>>>>> On 05/09/2018 02:40 PM, Pridhiviraj Paidipeddi wrote: >>>>>>>> Currently custom debug petitboot kernels failed to boot on >>>>>> secureboot >>>>>>>> enabled systems as the key verification fails results in >>>>>> enforcing the >>>>>>>> boot. Due to which debugging any problems in petitboot kernel in >>>>>>>> secure >>>>>>>> boot enabled systems become hard. >>>>>>>> This patch provides a way to disable secureboot in OPAL by using >>>>>> below >>>>>>>> nvram command. >>>>>>> >>>>>>> Petitboot verification should not be disabled if firmware secure >>>>>> boot >>>>>>> is on. Its only Host OS kernel >>>>>>> for which we can have the switch. >>>>>>> >>>>>>> This patch can result in a loophole where someone as application >>>>>> user >>>>>>> can disable >>>>>>> verification of petitboot kernel using nvram utility. >>>>>> >>>>>> Yeah, agree, but this is really a debug hack, without that there >>>>>> are >>>>>> bugs related to keys >>>>>> in upstream vs vendor released firmware, due to which verification >>>>>> fails >>>>>> and boot enforce >>>>>> happening on secureboot enabled systems, >>>>> >>>>> I'm not sure if I know what bug you are talking about here. Can you >>>>> elaborate more on that? >>>> >>>> Yes, Lets say p9dsu system is having latest supermicro released >>>> firmware(having imprint keys) >>>> and secureboot mode is enabled in the system. If we compile custom >>>> kernel in upstream op-build >>>> using development mode in signed mode and flash that on that failed >>>> secureboot system. so when >>>> we boot with that kernel, keys verification is failing, i am not >>>> sure why it is failing now, earlier >>>> it works when doing testing. The kernel tried from both the places >>>> one is zImage.epapr and another >>>> one is extracted BOOTKERNEL partition from full PNOR built in signed >>>> imprint mode. Using both the images >>>> verification is failing now. >>> >>> Hmm ... as long as the system trusts the imprinting keys (not any >>> production key), you should still be able to build and boot custom >>> zImage.epapr signed with imprinting keys. Do you remember how you >>> built (and signed) the zImage.epapr? >>> >> >> Yeah, on current upstream op-build, add this patch >> https://github.com/open-power/op-build/pull/1988 to enable >> secureboot and build signed imprint PNOR, before build we will add >> some custom patches to linux in openpower/linux folder >> and then do full op-build. Then try to flash the BOOTKERNEL which is >> extracted from full PNOR image built, then we >> will hit it. >> Does this happen if you flash the full PNOR image or only if try to >> flash the partition individually? If just the latter, maybe the >> partition reflash does not work exactly as we expect. > > Claudio, correct me if I'm wrong but I think flashing the zImage.epapr > will not work here because that is not a complete, signed container; > it is only the payload. > I have tried both payload image(zImage.epapr), BOOTKERNEL partition(signed container) extracted from full PNOR. Both are failed. And regarding full PNOR image, which is long ago bug system won't boot due to SBE's are messed up. > >> Thanks >> Pridhiviraj >> >>> Claudio >>> >>>> >>>>> >>>>> Thanks, >>>>> Claudio >>>>> >>>>>> so we need a way to force >>>>>> disable it, like the way >>>>>> we have for enabling it via nvram. Otherwise debugging petitboot >>>>>> kernels >>>>>> on such systems >>>>>> became really hard. >>>>>> >>>>>> Thanks >>>>>> Pridhiviraj >>>>>> >>>>>>> >>>>>>> Thanks & Regards, >>>>>>> - Nayna >>>>>>> >>>> >>>> _______________________________________________ >>>> Skiboot mailing list >>>> Skiboot@lists.ozlabs.org >>>> https://lists.ozlabs.org/listinfo/skiboot
On 5/11/2018 10:29 AM, ppaidipe wrote: > On 2018-05-11 18:49, hellerda wrote: >> On 5/11/2018 9:09 AM, ppaidipe wrote: >>> On 2018-05-11 18:24, Claudio Carvalho wrote: >>>> On 11/05/2018 09:33, ppaidipe wrote: >>>>> On 2018-05-11 17:47, Claudio Carvalho wrote: >>>>>> --- >>>>>> Claudio Carvalho >>>>>> Linux Security Development - IBM LTC >>>>>> >>>>>>> ----- Original message ----- >>>>>>> From: ppaidipe <ppaidipe@linux.vnet.ibm.com> >>>>>>> To: Nayna Jain <nayna@linux.vnet.ibm.com> >>>>>>> Cc: skiboot@lists.ozlabs.org, George Wilson <gcwilson@us.ibm.com>, >>>>>>> Claudio Carvalho/Brazil/IBM@IBMBR, hellerda@us.ibm.com, >>>>>>> erichte@us.ibm.com, sarahw@us.ibm.com >>>>>>> Subject: Re: [Skiboot] [PATCH] libstb/secureboot: Disable secureboot >>>>>>> in OPAL by nvram >>>>>>> Date: Fri, May 11, 2018 9:04 AM >>>>>>> >>>>>>> On 2018-05-11 16:52, Nayna Jain wrote: >>>>>>>> On 05/09/2018 02:40 PM, Pridhiviraj Paidipeddi wrote: >>>>>>>>> Currently custom debug petitboot kernels failed to boot on >>>>>>> secureboot >>>>>>>>> enabled systems as the key verification fails results in >>>>>>> enforcing the >>>>>>>>> boot. Due to which debugging any problems in petitboot kernel in >>>>>>>>> secure >>>>>>>>> boot enabled systems become hard. >>>>>>>>> This patch provides a way to disable secureboot in OPAL by using >>>>>>> below >>>>>>>>> nvram command. >>>>>>>> >>>>>>>> Petitboot verification should not be disabled if firmware secure >>>>>>> boot >>>>>>>> is on. Its only Host OS kernel >>>>>>>> for which we can have the switch. >>>>>>>> >>>>>>>> This patch can result in a loophole where someone as application >>>>>>> user >>>>>>>> can disable >>>>>>>> verification of petitboot kernel using nvram utility. >>>>>>> >>>>>>> Yeah, agree, but this is really a debug hack, without that there are >>>>>>> bugs related to keys >>>>>>> in upstream vs vendor released firmware, due to which verification >>>>>>> fails >>>>>>> and boot enforce >>>>>>> happening on secureboot enabled systems, >>>>>> >>>>>> I'm not sure if I know what bug you are talking about here. Can you >>>>>> elaborate more on that? >>>>> >>>>> Yes, Lets say p9dsu system is having latest supermicro released >>>>> firmware(having imprint keys) >>>>> and secureboot mode is enabled in the system. If we compile custom >>>>> kernel in upstream op-build >>>>> using development mode in signed mode and flash that on that failed >>>>> secureboot system. so when >>>>> we boot with that kernel, keys verification is failing, i am not >>>>> sure why it is failing now, earlier >>>>> it works when doing testing. The kernel tried from both the places >>>>> one is zImage.epapr and another >>>>> one is extracted BOOTKERNEL partition from full PNOR built in >>>>> signed imprint mode. Using both the images >>>>> verification is failing now. >>>> >>>> Hmm ... as long as the system trusts the imprinting keys (not any >>>> production key), you should still be able to build and boot custom >>>> zImage.epapr signed with imprinting keys. Do you remember how you >>>> built (and signed) the zImage.epapr? >>>> >>> >>> Yeah, on current upstream op-build, add this patch >>> https://github.com/open-power/op-build/pull/1988 to enable >>> secureboot and build signed imprint PNOR, before build we will add >>> some custom patches to linux in openpower/linux folder >>> and then do full op-build. Then try to flash the BOOTKERNEL which is >>> extracted from full PNOR image built, then we >>> will hit it. >>> Does this happen if you flash the full PNOR image or only if try to >>> flash the partition individually? If just the latter, maybe the >>> partition reflash does not work exactly as we expect. >> >> Claudio, correct me if I'm wrong but I think flashing the zImage.epapr >> will not work here because that is not a complete, signed container; >> it is only the payload. >> > > I have tried both payload image(zImage.epapr), BOOTKERNEL > partition(signed container) extracted > from full PNOR. Both are failed. And regarding full PNOR image, which is > long ago bug system won't > boot due to SBE's are messed up. > The zImage.epapr in the output/images directory is just the payload, not the full container. There is a file by the same name in the openpower_pnor_scratch/ directory that is a full container. You can check the files using the 'file' command, or examine them with print-container. Here is where I'm a little unsure: If you run print-container with the --validate option you will see that it fails validation. There is another file in openpower_pnor_scratch, the "rand-xxxxxxxxxx.BOOTKERNEL.temp.hdr.bin" file, that *does* validate. The difference is, the "hdr.bin" file has no padding applied, and the zImage.epapr has the padding. I'm not sure which is the correct file to flash. Probably it is the zImage.epapr with padding. Perhaps it does not matter. It would matter only if the secure boot code reads beyond the payload size, when loading the file. The padding ensures the remainder of the PNOR partition, after the end of payload, is all nulls. (At least, I *think* that's right). >> >>> Thanks >>> Pridhiviraj >>> >>>> Claudio >>>> >>>>> >>>>>> >>>>>> Thanks, >>>>>> Claudio >>>>>> >>>>>>> so we need a way to force >>>>>>> disable it, like the way >>>>>>> we have for enabling it via nvram. Otherwise debugging petitboot >>>>>>> kernels >>>>>>> on such systems >>>>>>> became really hard. >>>>>>> >>>>>>> Thanks >>>>>>> Pridhiviraj >>>>>>> >>>>>>>> >>>>>>>> Thanks & Regards, >>>>>>>> - Nayna >>>>>>>> >>>>> >>>>> _______________________________________________ >>>>> Skiboot mailing list >>>>> Skiboot@lists.ozlabs.org >>>>> https://lists.ozlabs.org/listinfo/skiboot
On 11/05/2018 12:46, hellerda wrote: > > On 5/11/2018 10:29 AM, ppaidipe wrote: >> On 2018-05-11 18:49, hellerda wrote: >>> On 5/11/2018 9:09 AM, ppaidipe wrote: >>>> On 2018-05-11 18:24, Claudio Carvalho wrote: >>>>> On 11/05/2018 09:33, ppaidipe wrote: >>>>>> On 2018-05-11 17:47, Claudio Carvalho wrote: >>>>>>> --- >>>>>>> Claudio Carvalho >>>>>>> Linux Security Development - IBM LTC >>>>>>> >>>>>>>> ----- Original message ----- >>>>>>>> From: ppaidipe <ppaidipe@linux.vnet.ibm.com> >>>>>>>> To: Nayna Jain <nayna@linux.vnet.ibm.com> >>>>>>>> Cc: skiboot@lists.ozlabs.org, George Wilson <gcwilson@us.ibm.com>, >>>>>>>> Claudio Carvalho/Brazil/IBM@IBMBR, hellerda@us.ibm.com, >>>>>>>> erichte@us.ibm.com, sarahw@us.ibm.com >>>>>>>> Subject: Re: [Skiboot] [PATCH] libstb/secureboot: Disable >>>>>>>> secureboot >>>>>>>> in OPAL by nvram >>>>>>>> Date: Fri, May 11, 2018 9:04 AM >>>>>>>> >>>>>>>> On 2018-05-11 16:52, Nayna Jain wrote: >>>>>>>>> On 05/09/2018 02:40 PM, Pridhiviraj Paidipeddi wrote: >>>>>>>>>> Currently custom debug petitboot kernels failed to boot on >>>>>>>> secureboot >>>>>>>>>> enabled systems as the key verification fails results in >>>>>>>> enforcing the >>>>>>>>>> boot. Due to which debugging any problems in petitboot kernel in >>>>>>>>>> secure >>>>>>>>>> boot enabled systems become hard. >>>>>>>>>> This patch provides a way to disable secureboot in OPAL by using >>>>>>>> below >>>>>>>>>> nvram command. >>>>>>>>> >>>>>>>>> Petitboot verification should not be disabled if firmware secure >>>>>>>> boot >>>>>>>>> is on. Its only Host OS kernel >>>>>>>>> for which we can have the switch. >>>>>>>>> >>>>>>>>> This patch can result in a loophole where someone as application >>>>>>>> user >>>>>>>>> can disable >>>>>>>>> verification of petitboot kernel using nvram utility. >>>>>>>> >>>>>>>> Yeah, agree, but this is really a debug hack, without that >>>>>>>> there are >>>>>>>> bugs related to keys >>>>>>>> in upstream vs vendor released firmware, due to which verification >>>>>>>> fails >>>>>>>> and boot enforce >>>>>>>> happening on secureboot enabled systems, >>>>>>> >>>>>>> I'm not sure if I know what bug you are talking about here. Can you >>>>>>> elaborate more on that? >>>>>> >>>>>> Yes, Lets say p9dsu system is having latest supermicro released >>>>>> firmware(having imprint keys) >>>>>> and secureboot mode is enabled in the system. If we compile >>>>>> custom kernel in upstream op-build >>>>>> using development mode in signed mode and flash that on that >>>>>> failed secureboot system. so when >>>>>> we boot with that kernel, keys verification is failing, i am not >>>>>> sure why it is failing now, earlier >>>>>> it works when doing testing. The kernel tried from both the >>>>>> places one is zImage.epapr and another >>>>>> one is extracted BOOTKERNEL partition from full PNOR built in >>>>>> signed imprint mode. Using both the images >>>>>> verification is failing now. >>>>> >>>>> Hmm ... as long as the system trusts the imprinting keys (not any >>>>> production key), you should still be able to build and boot custom >>>>> zImage.epapr signed with imprinting keys. Do you remember how you >>>>> built (and signed) the zImage.epapr? >>>>> >>>> >>>> Yeah, on current upstream op-build, add this patch >>>> https://github.com/open-power/op-build/pull/1988 to enable >>>> secureboot and build signed imprint PNOR, before build we will add >>>> some custom patches to linux in openpower/linux folder >>>> and then do full op-build. Then try to flash the BOOTKERNEL which >>>> is extracted from full PNOR image built, then we >>>> will hit it. >>>> Does this happen if you flash the full PNOR image or only if try to >>>> flash the partition individually? If just the latter, maybe the >>>> partition reflash does not work exactly as we expect. >>> >>> Claudio, correct me if I'm wrong but I think flashing the zImage.epapr >>> will not work here because that is not a complete, signed container; >>> it is only the payload. >>> >> >> I have tried both payload image(zImage.epapr), BOOTKERNEL >> partition(signed container) extracted >> from full PNOR. Both are failed. And regarding full PNOR image, which >> is long ago bug system won't >> boot due to SBE's are messed up. >> > The zImage.epapr in the output/images directory is just the payload, > not the full container. There is a file by the same name in the > openpower_pnor_scratch/ directory that is a full container. You can > check the files using the 'file' command, or examine them with > print-container. > > Here is where I'm a little unsure: If you run print-container with the > --validate option you will see that it fails validation. There is > another file in openpower_pnor_scratch, the > "rand-xxxxxxxxxx.BOOTKERNEL.temp.hdr.bin" file, that *does* validate. > The difference is, the "hdr.bin" file has no padding applied, and the > zImage.epapr has the padding. > > I'm not sure which is the correct file to flash. Probably it is the > zImage.epapr with padding. Perhaps it does not matter. It would > matter only if the secure boot code reads beyond the payload size, > when loading the file. The padding ensures the remainder of the PNOR > partition, after the end of payload, is all nulls. (At least, I > *think* that's right). Does the payload size stored in the container consider the padding? The secure rom code will use that to validate the container. Claudio > >>> >>>> Thanks >>>> Pridhiviraj >>>> >>>>> Claudio >>>>> >>>>>> >>>>>>> >>>>>>> Thanks, >>>>>>> Claudio >>>>>>> >>>>>>>> so we need a way to force >>>>>>>> disable it, like the way >>>>>>>> we have for enabling it via nvram. Otherwise debugging petitboot >>>>>>>> kernels >>>>>>>> on such systems >>>>>>>> became really hard. >>>>>>>> >>>>>>>> Thanks >>>>>>>> Pridhiviraj >>>>>>>> >>>>>>>>> >>>>>>>>> Thanks & Regards, >>>>>>>>> - Nayna >>>>>>>>> >>>>>> >>>>>> _______________________________________________ >>>>>> Skiboot mailing list >>>>>> Skiboot@lists.ozlabs.org >>>>>> https://lists.ozlabs.org/listinfo/skiboot >
On 5/11/2018 12:20 PM, Claudio Carvalho wrote: > > > On 11/05/2018 12:46, hellerda wrote: >> >> On 5/11/2018 10:29 AM, ppaidipe wrote: >>> On 2018-05-11 18:49, hellerda wrote: >>>> On 5/11/2018 9:09 AM, ppaidipe wrote: >>>>> On 2018-05-11 18:24, Claudio Carvalho wrote: >>>>>> On 11/05/2018 09:33, ppaidipe wrote: >>>>>>> On 2018-05-11 17:47, Claudio Carvalho wrote: >>>>>>>> --- >>>>>>>> Claudio Carvalho >>>>>>>> Linux Security Development - IBM LTC >>>>>>>> >>>>>>>>> ----- Original message ----- >>>>>>>>> From: ppaidipe <ppaidipe@linux.vnet.ibm.com> >>>>>>>>> To: Nayna Jain <nayna@linux.vnet.ibm.com> >>>>>>>>> Cc: skiboot@lists.ozlabs.org, George Wilson <gcwilson@us.ibm.com>, >>>>>>>>> Claudio Carvalho/Brazil/IBM@IBMBR, hellerda@us.ibm.com, >>>>>>>>> erichte@us.ibm.com, sarahw@us.ibm.com >>>>>>>>> Subject: Re: [Skiboot] [PATCH] libstb/secureboot: Disable >>>>>>>>> secureboot >>>>>>>>> in OPAL by nvram >>>>>>>>> Date: Fri, May 11, 2018 9:04 AM >>>>>>>>> >>>>>>>>> On 2018-05-11 16:52, Nayna Jain wrote: >>>>>>>>>> On 05/09/2018 02:40 PM, Pridhiviraj Paidipeddi wrote: >>>>>>>>>>> Currently custom debug petitboot kernels failed to boot on >>>>>>>>> secureboot >>>>>>>>>>> enabled systems as the key verification fails results in >>>>>>>>> enforcing the >>>>>>>>>>> boot. Due to which debugging any problems in petitboot kernel in >>>>>>>>>>> secure >>>>>>>>>>> boot enabled systems become hard. >>>>>>>>>>> This patch provides a way to disable secureboot in OPAL by using >>>>>>>>> below >>>>>>>>>>> nvram command. >>>>>>>>>> >>>>>>>>>> Petitboot verification should not be disabled if firmware secure >>>>>>>>> boot >>>>>>>>>> is on. Its only Host OS kernel >>>>>>>>>> for which we can have the switch. >>>>>>>>>> >>>>>>>>>> This patch can result in a loophole where someone as application >>>>>>>>> user >>>>>>>>>> can disable >>>>>>>>>> verification of petitboot kernel using nvram utility. >>>>>>>>> >>>>>>>>> Yeah, agree, but this is really a debug hack, without that >>>>>>>>> there are >>>>>>>>> bugs related to keys >>>>>>>>> in upstream vs vendor released firmware, due to which verification >>>>>>>>> fails >>>>>>>>> and boot enforce >>>>>>>>> happening on secureboot enabled systems, >>>>>>>> >>>>>>>> I'm not sure if I know what bug you are talking about here. Can you >>>>>>>> elaborate more on that? >>>>>>> >>>>>>> Yes, Lets say p9dsu system is having latest supermicro released >>>>>>> firmware(having imprint keys) >>>>>>> and secureboot mode is enabled in the system. If we compile >>>>>>> custom kernel in upstream op-build >>>>>>> using development mode in signed mode and flash that on that >>>>>>> failed secureboot system. so when >>>>>>> we boot with that kernel, keys verification is failing, i am not >>>>>>> sure why it is failing now, earlier >>>>>>> it works when doing testing. The kernel tried from both the >>>>>>> places one is zImage.epapr and another >>>>>>> one is extracted BOOTKERNEL partition from full PNOR built in >>>>>>> signed imprint mode. Using both the images >>>>>>> verification is failing now. >>>>>> >>>>>> Hmm ... as long as the system trusts the imprinting keys (not any >>>>>> production key), you should still be able to build and boot custom >>>>>> zImage.epapr signed with imprinting keys. Do you remember how you >>>>>> built (and signed) the zImage.epapr? >>>>>> >>>>> >>>>> Yeah, on current upstream op-build, add this patch >>>>> https://github.com/open-power/op-build/pull/1988 to enable >>>>> secureboot and build signed imprint PNOR, before build we will add >>>>> some custom patches to linux in openpower/linux folder >>>>> and then do full op-build. Then try to flash the BOOTKERNEL which >>>>> is extracted from full PNOR image built, then we >>>>> will hit it. >>>>> Does this happen if you flash the full PNOR image or only if try to >>>>> flash the partition individually? If just the latter, maybe the >>>>> partition reflash does not work exactly as we expect. >>>> >>>> Claudio, correct me if I'm wrong but I think flashing the zImage.epapr >>>> will not work here because that is not a complete, signed container; >>>> it is only the payload. >>>> >>> >>> I have tried both payload image(zImage.epapr), BOOTKERNEL >>> partition(signed container) extracted >>> from full PNOR. Both are failed. And regarding full PNOR image, which >>> is long ago bug system won't >>> boot due to SBE's are messed up. >>> >> The zImage.epapr in the output/images directory is just the payload, >> not the full container. There is a file by the same name in the >> openpower_pnor_scratch/ directory that is a full container. You can >> check the files using the 'file' command, or examine them with >> print-container. >> >> Here is where I'm a little unsure: If you run print-container with the >> --validate option you will see that it fails validation. There is >> another file in openpower_pnor_scratch, the >> "rand-xxxxxxxxxx.BOOTKERNEL.temp.hdr.bin" file, that *does* validate. >> The difference is, the "hdr.bin" file has no padding applied, and the >> zImage.epapr has the padding. >> >> I'm not sure which is the correct file to flash. Probably it is the >> zImage.epapr with padding. Perhaps it does not matter. It would >> matter only if the secure boot code reads beyond the payload size, >> when loading the file. The padding ensures the remainder of the PNOR >> partition, after the end of payload, is all nulls. (At least, I >> *think* that's right). > > Does the payload size stored in the container consider the padding? The > secure rom code will use that to validate the container. > > The payload size in the header does not include the padding. (which is why the padded file fails validation with print-container, while the unpadded file passes. I should add an option to print-container to make it consider only payload_size bytes when doing the payload hash calculation, so it could be used to check the padded as well as unpadded files). -Dave > Claudio > > >> >>>> >>>>> Thanks >>>>> Pridhiviraj >>>>> >>>>>> Claudio >>>>>> >>>>>>> >>>>>>>> >>>>>>>> Thanks, >>>>>>>> Claudio >>>>>>>> >>>>>>>>> so we need a way to force >>>>>>>>> disable it, like the way >>>>>>>>> we have for enabling it via nvram. Otherwise debugging petitboot >>>>>>>>> kernels >>>>>>>>> on such systems >>>>>>>>> became really hard. >>>>>>>>> >>>>>>>>> Thanks >>>>>>>>> Pridhiviraj >>>>>>>>> >>>>>>>>>> >>>>>>>>>> Thanks & Regards, >>>>>>>>>> - Nayna >>>>>>>>>> >>>>>>> >>>>>>> _______________________________________________ >>>>>>> Skiboot mailing list >>>>>>> Skiboot@lists.ozlabs.org >>>>>>> https://lists.ozlabs.org/listinfo/skiboot >> >
On 5/11/2018 12:40 PM, hellerda wrote: > On 5/11/2018 12:20 PM, Claudio Carvalho wrote: >> >> >> On 11/05/2018 12:46, hellerda wrote: >>> >>> On 5/11/2018 10:29 AM, ppaidipe wrote: >>>> On 2018-05-11 18:49, hellerda wrote: >>>>> On 5/11/2018 9:09 AM, ppaidipe wrote: >>>>>> On 2018-05-11 18:24, Claudio Carvalho wrote: >>>>>>> On 11/05/2018 09:33, ppaidipe wrote: >>>>>>>> On 2018-05-11 17:47, Claudio Carvalho wrote: >>>>>>>>> --- >>>>>>>>> Claudio Carvalho >>>>>>>>> Linux Security Development - IBM LTC >>>>>>>>> >>>>>>>>>> ----- Original message ----- >>>>>>>>>> From: ppaidipe <ppaidipe@linux.vnet.ibm.com> >>>>>>>>>> To: Nayna Jain <nayna@linux.vnet.ibm.com> >>>>>>>>>> Cc: skiboot@lists.ozlabs.org, George Wilson >>>>>>>>>> <gcwilson@us.ibm.com>, >>>>>>>>>> Claudio Carvalho/Brazil/IBM@IBMBR, hellerda@us.ibm.com, >>>>>>>>>> erichte@us.ibm.com, sarahw@us.ibm.com >>>>>>>>>> Subject: Re: [Skiboot] [PATCH] libstb/secureboot: Disable >>>>>>>>>> secureboot >>>>>>>>>> in OPAL by nvram >>>>>>>>>> Date: Fri, May 11, 2018 9:04 AM >>>>>>>>>> >>>>>>>>>> On 2018-05-11 16:52, Nayna Jain wrote: >>>>>>>>>>> On 05/09/2018 02:40 PM, Pridhiviraj Paidipeddi wrote: >>>>>>>>>>>> Currently custom debug petitboot kernels failed to boot on >>>>>>>>>> secureboot >>>>>>>>>>>> enabled systems as the key verification fails results in >>>>>>>>>> enforcing the >>>>>>>>>>>> boot. Due to which debugging any problems in petitboot >>>>>>>>>>>> kernel in >>>>>>>>>>>> secure >>>>>>>>>>>> boot enabled systems become hard. >>>>>>>>>>>> This patch provides a way to disable secureboot in OPAL by >>>>>>>>>>>> using >>>>>>>>>> below >>>>>>>>>>>> nvram command. >>>>>>>>>>> >>>>>>>>>>> Petitboot verification should not be disabled if firmware secure >>>>>>>>>> boot >>>>>>>>>>> is on. Its only Host OS kernel >>>>>>>>>>> for which we can have the switch. >>>>>>>>>>> >>>>>>>>>>> This patch can result in a loophole where someone as application >>>>>>>>>> user >>>>>>>>>>> can disable >>>>>>>>>>> verification of petitboot kernel using nvram utility. >>>>>>>>>> >>>>>>>>>> Yeah, agree, but this is really a debug hack, without that >>>>>>>>>> there are >>>>>>>>>> bugs related to keys >>>>>>>>>> in upstream vs vendor released firmware, due to which >>>>>>>>>> verification >>>>>>>>>> fails >>>>>>>>>> and boot enforce >>>>>>>>>> happening on secureboot enabled systems, >>>>>>>>> >>>>>>>>> I'm not sure if I know what bug you are talking about here. Can >>>>>>>>> you >>>>>>>>> elaborate more on that? >>>>>>>> >>>>>>>> Yes, Lets say p9dsu system is having latest supermicro released >>>>>>>> firmware(having imprint keys) >>>>>>>> and secureboot mode is enabled in the system. If we compile >>>>>>>> custom kernel in upstream op-build >>>>>>>> using development mode in signed mode and flash that on that >>>>>>>> failed secureboot system. so when >>>>>>>> we boot with that kernel, keys verification is failing, i am not >>>>>>>> sure why it is failing now, earlier >>>>>>>> it works when doing testing. The kernel tried from both the >>>>>>>> places one is zImage.epapr and another >>>>>>>> one is extracted BOOTKERNEL partition from full PNOR built in >>>>>>>> signed imprint mode. Using both the images >>>>>>>> verification is failing now. >>>>>>> >>>>>>> Hmm ... as long as the system trusts the imprinting keys (not any >>>>>>> production key), you should still be able to build and boot custom >>>>>>> zImage.epapr signed with imprinting keys. Do you remember how you >>>>>>> built (and signed) the zImage.epapr? >>>>>>> >>>>>> >>>>>> Yeah, on current upstream op-build, add this patch >>>>>> https://github.com/open-power/op-build/pull/1988 to enable >>>>>> secureboot and build signed imprint PNOR, before build we will add >>>>>> some custom patches to linux in openpower/linux folder >>>>>> and then do full op-build. Then try to flash the BOOTKERNEL which >>>>>> is extracted from full PNOR image built, then we >>>>>> will hit it. >>>>>> Does this happen if you flash the full PNOR image or only if try >>>>>> to flash the partition individually? If just the latter, maybe >>>>>> the partition reflash does not work exactly as we expect. >>>>> >>>>> Claudio, correct me if I'm wrong but I think flashing the zImage.epapr >>>>> will not work here because that is not a complete, signed container; >>>>> it is only the payload. >>>>> >>>> >>>> I have tried both payload image(zImage.epapr), BOOTKERNEL >>>> partition(signed container) extracted >>>> from full PNOR. Both are failed. And regarding full PNOR image, >>>> which is long ago bug system won't >>>> boot due to SBE's are messed up. >>>> >>> The zImage.epapr in the output/images directory is just the payload, >>> not the full container. There is a file by the same name in the >>> openpower_pnor_scratch/ directory that is a full container. You can >>> check the files using the 'file' command, or examine them with >>> print-container. >>> >>> Here is where I'm a little unsure: If you run print-container with >>> the --validate option you will see that it fails validation. There is >>> another file in openpower_pnor_scratch, the >>> "rand-xxxxxxxxxx.BOOTKERNEL.temp.hdr.bin" file, that *does* validate. >>> The difference is, the "hdr.bin" file has no padding applied, and the >>> zImage.epapr has the padding. >>> >>> I'm not sure which is the correct file to flash. Probably it is the >>> zImage.epapr with padding. Perhaps it does not matter. It would >>> matter only if the secure boot code reads beyond the payload size, >>> when loading the file. The padding ensures the remainder of the PNOR >>> partition, after the end of payload, is all nulls. (At least, I >>> *think* that's right). >> >> Does the payload size stored in the container consider the padding? >> The secure rom code will use that to validate the container. >> > > The payload size in the header does not include the padding. (which is > why the padded file fails validation with print-container, while the > unpadded file passes. I should add an option to print-container to make > it consider only payload_size bytes when doing the payload hash > calculation, so it could be used to check the padded as well as unpadded > files). -Dave > I just added the option --validate-ignore-remainder to print-container. With this you should be able to validate padded files, including the zImage.epapr in the openpower_pnor_scratch directory. You can try it at https://github.com/open-power/sb-signing-utils/pull/25. > >> Claudio >> >> >>> >>>>> >>>>>> Thanks >>>>>> Pridhiviraj >>>>>> >>>>>>> Claudio >>>>>>> >>>>>>>> >>>>>>>>> >>>>>>>>> Thanks, >>>>>>>>> Claudio >>>>>>>>> >>>>>>>>>> so we need a way to force >>>>>>>>>> disable it, like the way >>>>>>>>>> we have for enabling it via nvram. Otherwise debugging petitboot >>>>>>>>>> kernels >>>>>>>>>> on such systems >>>>>>>>>> became really hard. >>>>>>>>>> >>>>>>>>>> Thanks >>>>>>>>>> Pridhiviraj >>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> Thanks & Regards, >>>>>>>>>>> - Nayna >>>>>>>>>>> >>>>>>>> >>>>>>>> _______________________________________________ >>>>>>>> Skiboot mailing list >>>>>>>> Skiboot@lists.ozlabs.org >>>>>>>> https://lists.ozlabs.org/listinfo/skiboot >>> >> > > _______________________________________________ > Skiboot mailing list > Skiboot@lists.ozlabs.org > https://lists.ozlabs.org/listinfo/skiboot
hellerda <hellerda@linux.vnet.ibm.com> writes: > On 5/11/2018 10:29 AM, ppaidipe wrote: >> On 2018-05-11 18:49, hellerda wrote: >>> On 5/11/2018 9:09 AM, ppaidipe wrote: >>>> On 2018-05-11 18:24, Claudio Carvalho wrote: >>>>> On 11/05/2018 09:33, ppaidipe wrote: >>>>>> On 2018-05-11 17:47, Claudio Carvalho wrote: >>>>>>> --- >>>>>>> Claudio Carvalho >>>>>>> Linux Security Development - IBM LTC >>>>>>> >>>>>>>> ----- Original message ----- >>>>>>>> From: ppaidipe <ppaidipe@linux.vnet.ibm.com> >>>>>>>> To: Nayna Jain <nayna@linux.vnet.ibm.com> >>>>>>>> Cc: skiboot@lists.ozlabs.org, George Wilson <gcwilson@us.ibm.com>, >>>>>>>> Claudio Carvalho/Brazil/IBM@IBMBR, hellerda@us.ibm.com, >>>>>>>> erichte@us.ibm.com, sarahw@us.ibm.com >>>>>>>> Subject: Re: [Skiboot] [PATCH] libstb/secureboot: Disable secureboot >>>>>>>> in OPAL by nvram >>>>>>>> Date: Fri, May 11, 2018 9:04 AM >>>>>>>> >>>>>>>> On 2018-05-11 16:52, Nayna Jain wrote: >>>>>>>>> On 05/09/2018 02:40 PM, Pridhiviraj Paidipeddi wrote: >>>>>>>>>> Currently custom debug petitboot kernels failed to boot on >>>>>>>> secureboot >>>>>>>>>> enabled systems as the key verification fails results in >>>>>>>> enforcing the >>>>>>>>>> boot. Due to which debugging any problems in petitboot kernel in >>>>>>>>>> secure >>>>>>>>>> boot enabled systems become hard. >>>>>>>>>> This patch provides a way to disable secureboot in OPAL by using >>>>>>>> below >>>>>>>>>> nvram command. >>>>>>>>> >>>>>>>>> Petitboot verification should not be disabled if firmware secure >>>>>>>> boot >>>>>>>>> is on. Its only Host OS kernel >>>>>>>>> for which we can have the switch. >>>>>>>>> >>>>>>>>> This patch can result in a loophole where someone as application >>>>>>>> user >>>>>>>>> can disable >>>>>>>>> verification of petitboot kernel using nvram utility. >>>>>>>> >>>>>>>> Yeah, agree, but this is really a debug hack, without that there are >>>>>>>> bugs related to keys >>>>>>>> in upstream vs vendor released firmware, due to which verification >>>>>>>> fails >>>>>>>> and boot enforce >>>>>>>> happening on secureboot enabled systems, >>>>>>> >>>>>>> I'm not sure if I know what bug you are talking about here. Can you >>>>>>> elaborate more on that? >>>>>> >>>>>> Yes, Lets say p9dsu system is having latest supermicro released >>>>>> firmware(having imprint keys) >>>>>> and secureboot mode is enabled in the system. If we compile custom >>>>>> kernel in upstream op-build >>>>>> using development mode in signed mode and flash that on that failed >>>>>> secureboot system. so when >>>>>> we boot with that kernel, keys verification is failing, i am not >>>>>> sure why it is failing now, earlier >>>>>> it works when doing testing. The kernel tried from both the places >>>>>> one is zImage.epapr and another >>>>>> one is extracted BOOTKERNEL partition from full PNOR built in >>>>>> signed imprint mode. Using both the images >>>>>> verification is failing now. >>>>> >>>>> Hmm ... as long as the system trusts the imprinting keys (not any >>>>> production key), you should still be able to build and boot custom >>>>> zImage.epapr signed with imprinting keys. Do you remember how you >>>>> built (and signed) the zImage.epapr? >>>>> >>>> >>>> Yeah, on current upstream op-build, add this patch >>>> https://github.com/open-power/op-build/pull/1988 to enable >>>> secureboot and build signed imprint PNOR, before build we will add >>>> some custom patches to linux in openpower/linux folder >>>> and then do full op-build. Then try to flash the BOOTKERNEL which is >>>> extracted from full PNOR image built, then we >>>> will hit it. >>>> Does this happen if you flash the full PNOR image or only if try to >>>> flash the partition individually? If just the latter, maybe the >>>> partition reflash does not work exactly as we expect. >>> >>> Claudio, correct me if I'm wrong but I think flashing the zImage.epapr >>> will not work here because that is not a complete, signed container; >>> it is only the payload. >>> >> >> I have tried both payload image(zImage.epapr), BOOTKERNEL >> partition(signed container) extracted >> from full PNOR. Both are failed. And regarding full PNOR image, which is >> long ago bug system won't >> boot due to SBE's are messed up. >> > The zImage.epapr in the output/images directory is just the payload, not > the full container. There is a file by the same name in the > openpower_pnor_scratch/ directory that is a full container. You can > check the files using the 'file' command, or examine them with > print-container. > > Here is where I'm a little unsure: If you run print-container with the > --validate option you will see that it fails validation. There is > another file in openpower_pnor_scratch, the > "rand-xxxxxxxxxx.BOOTKERNEL.temp.hdr.bin" file, that *does* validate. > The difference is, the "hdr.bin" file has no padding applied, and the > zImage.epapr has the padding. > > I'm not sure which is the correct file to flash. Probably it is the > zImage.epapr with padding. Perhaps it does not matter. It would matter > only if the secure boot code reads beyond the payload size, when loading > the file. The padding ensures the remainder of the PNOR partition, > after the end of payload, is all nulls. (At least, I *think* that's > right). It shouldn't make a difference as the signature should just be across the content of the partition and not the full thing, otherwise we certainly have a decent sized bug.
Pridhiviraj Paidipeddi <ppaidipe@linux.vnet.ibm.com> writes: > Currently custom debug petitboot kernels failed to boot on secureboot > enabled systems as the key verification fails results in enforcing the > boot. Due to which debugging any problems in petitboot kernel in secure > boot enabled systems become hard. > This patch provides a way to disable secureboot in OPAL by using below > nvram command. > nvram -p ibm,skiboot --update-config force-secure-mode=false As mentioned by others, this isn't something I can take for upstream as it really does bypass the point of secure mode.
diff --git a/libstb/secureboot.c b/libstb/secureboot.c index 348acf5..8c8a9d6 100644 --- a/libstb/secureboot.c +++ b/libstb/secureboot.c @@ -107,6 +107,9 @@ void secureboot_init(void) if (nvram_query_eq("force-secure-mode", "always")) { secure_mode = true; prlog(PR_NOTICE, "secure mode on (FORCED by nvram)\n"); + } else if (nvram_query_eq("force-secure-mode", "false")) { + secure_mode = false; + prlog(PR_NOTICE, "secure mode off (FORCED by nvram)\n"); } else { secure_mode = dt_has_node_property(node, "secure-enabled", NULL); prlog(PR_NOTICE, "secure mode %s\n",
Currently custom debug petitboot kernels failed to boot on secureboot enabled systems as the key verification fails results in enforcing the boot. Due to which debugging any problems in petitboot kernel in secure boot enabled systems become hard. This patch provides a way to disable secureboot in OPAL by using below nvram command. nvram -p ibm,skiboot --update-config force-secure-mode=false Signed-off-by: Pridhiviraj Paidipeddi <ppaidipe@linux.vnet.ibm.com> --- libstb/secureboot.c | 3 +++ 1 file changed, 3 insertions(+)