February 2020 - tpm2 - Ml01.01.Org

OpenSSL TLS using tpm2-pkcs11 doesn't work on newer versions

by Ignacio Jaureguiberry

I was trying to make wpa_supplicant use a tpm2-pkcs11 stored private key to authenticate against a RADIUS server, I mentioned about it on this discussion: https://lists.01.org/hyperkitty/list/tpm2@lists.01.org/message/AYUBCAFCCX... With some fixes on tpm2-pkcs11, TLS is working and there is an integration test for that here: https://github.com/tpm2-software/tpm2-pkcs11/blob/master/test/integration... I wasn't able to reproduce this on Ubuntu 18, and noted that the test cases ran on top of an Ubuntu 16.04 image. I tried Ubuntu 16.04 and TLS works as in the integration test. I also checked that using latest version of wpa_supplicant, it does work with tpm2-pkcs11 and creates an EAP-TLS connection using the TPM. I've debugged a bit in both OS versions and found that openssl is calling pkey_rsa_sign with different padding modes: RSA_PKCS1_PADDING in Ubuntu 16, and RSA_PKCS1_PSS_PADDING in Ubuntu 18. The consequence is that in tpm2-pkcs11, sign_init is being called using CKM_RSA_PKCS as mechanism on Ubuntu 16, but in Ubuntu 18 it is being called with CKM_RSA_X_509, which is not supported. I think I have to file a bug to OpenSSL, but I don't know too much about the PKCS11 specs to support the claims. I'd appreciate any help to file a decent issue. Also, any workaround is welcome, as replacing OpenSSL in any distribution is very hard given all the software that depends on it.

2 years, 5 months

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tpm2_createek and transient EK problem

by Martin Townsend

Hi, I'm trying out the tpm2_createek tool and in the manual https://github.com/tpm2-software/tpm2-tools/blob/master/man/tpm2_createek... It explains how to create a transient EK, I following these instructions but can't get them to work. I've taken ownership of the TPM and created a SRK. I then ran the command as listed in the manual page: tpm2_createek -G rsa -u ek.pub ERROR: Expected option -c Usage: tpm2_createek [<options>] Where <options> are: [ -P | --eh-auth=<value>] [ -w | --owner-auth=<value>] [ -p | --ek-auth=<value>] [ -G | --key-algorithm=<value>] [ -u | --public=<value>] [ -f | --format=<value>] [ -c | --ek-context=<value>] [ -t | --template=<value>] So I added the -c to save the context to disk and provide the EH authorisation: tpm2_createek -G rsa -u ek.pub -c ek.ctx -P xxx echo $? 0 so it looks like it's succeeded but I then try the to list the transient objects with tpm2_getcap handles-transient and I get nothing. The files have been created ls -la ek* -rw-r--r-- 1 root root 1287 Feb 28 2020 ek.ctx -rw-r--r-- 1 root root 316 Feb 28 2020 ek.pub Any ideas as to why this is not working for me, do I need to perform some other step first? Many Thanks, Martin.

2 years, 6 months

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Made an ZFS root pool auto-unlock, please give review of method

by Garrett Fields

Back in the end of July, I wrote a message on this discussion list titled "PCR Policy enforcement when using nvram". In that, I asked for a way to have both a PCR check AND a password lock an nvram range (not an OR). I really appreciated everyone's help, especially William Roberts, who gave some sample code of using a session to accomplish this goal. Now that Ubuntu has updated its repositories for the upcoming 20.04 LTS release and included TPM-tools v4.x, I figured it was time to take another look. My goal is to provide a method to auto-unlock a ZFS encrypted root filesystem. Currently, ZFS allows for unlocking via a prompt or file containing a raw, hex, or passphrase values. The mechanisms are already inplace to prompt on startup. So far I have just done a proof of concept. It probably loads of bad code and tons of polish needed: https://github.com/ghfields/zfs/compare/master...ghfields:tpm2-autounlock I forked the zfs project, expanded the its initramfs hooks to include the required tpm2-tools binaries, and added another stanza to init script's decrypting section. I also created a pair of scripts that configures the system and tests readback. The nvram index and the PCRs used are stored/read from the zfs filesystem properties. I used the filesytem's GUID as the required password as another check to verify the NVRAM range was intended for that filesystem. I also intend to issue an nvreadlock to prevent snooping once the key is used. I'd be interested in a critique of the method overall I expect there ways to make this more secure. With enough effort, one could issue a break=premount on the kernel line and manually extract the password from the TPM. Any way to tighten that up? I'm a total novice at TPM in general, but am completely open to advise and guidance. Thanks, Garrett Fields

2 years, 6 months

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Question about RSA 2048 AK key size

by Chenxi Z

I created a 2048 RSA AK by using the command below : tpm2_createak -C 0x81010001 -c ak.ctx -u ak.pub -r ak.priv -n ak.name -P dummypwd -p dummypwd ak.priv file size = 224 bytes #stat --printf="%s" ak.priv 224 ak.pub file size = 282 bytes. $stat --printf="%s" ak.pub 282 Question: Do the AK private key and public key always have the same key sizes, ie, 224 and 282? Is there any possibility that the key size could be changed because of random number or big prime number changes during key generation? TPM2 tools version: tpm2-tools-4.1.1 tpm2-abrmd-2.3.1 tpm2-tss-2.3.2

2 years, 7 months

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How can I get EK certificate?

by Chenxi Z

Anyone knows how to get EK certificate? I am able to get EK public key by using the command below, but not sure how to get EK cert. #tpm2_readpublic -c 0x81010001 -o ek.pub.pem -f pem TPM2 tools version: tpm2-tools-4.1.1 tpm2-abrmd-2.3.1 tpm2-tss-2.3.2

2 years, 7 months

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tpm2-tss v2.4.0-rc3

by Tadeusz Struk

Hello, Another release candidate-rc3 for tpm2-tss v2.4.0 is out. https://github.com/tpm2-software/tpm2-tss/releases/tag/2.4.0-rc3 All changes and fixes are listed in the CHANGELOG.md file. Any feedback welcomed. Thanks, -- Tadeusz

2 years, 7 months

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[RC] tpm2-pkcs11: 1.1.0-RC0

by Roberts, William C

Hello, I'd like to announce tpm2-pkcs11 release candidate 1.1.0-RC0 https://github.com/tpm2-software/tpm2-pkcs11/releases/tag/1.1.0-RC0 BACKUP YOUR DB WHEN UPGRADING. Although the code was designed to upgrade a copy And only swap the DB when the upgrade path succeeds, I always recommend keeping a backup of your store for those just in case situations. Changelog: 1.1.0-RC0 - 2020-02-24 * DB Schema Change from 1 to 3. - **Backup your DB before upgrading** * Support C_InitToken interface. * Add Java PKCS11 Keystore support for RSA/ECB/RSAPKCS1.5 via public encrypt and private decrypt. * Decouple handles from db primary keys. Key handles are no longer stable between runs. * tpm2_ptool objmod: - Support adding an attribute. - Fix bug in variable name vtype over type. * C_Sign: support mechanism CKM_RSA_X_509. * C_GetTokenInfo: add missing mechanism CKM_SHA512_RSA_PKCS. * Fix store search logic to fail when TPM2_PKCS11_STORE cannot be accessed. * Fix potential double free in token_free() logic. * Fix -Werror=format-truncation with GCC >= 7 #415

2 years, 7 months

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Infineon SLB 9670 lifetime

by Tomasz Przybysz

Hi, Do you know ? From data sheet: SLB 9670 TPM2.0 SLB 9670 TCG Family 2 Level 00 Rev. 01.16 Data Sheet, Revision 1.0, 2015-11-05: 1.1 Power Management In the SLB 9670, power management is handled internally; no explicit power-down or standby mode is available. The device automatically enters a low-power state after each successful command/response transaction. If a transaction is started on the SPI bus from the host platform, the device will wake immediately and will return to the low-power mode after the transaction has been finished. 4.2 Functional Operating Range 1) The useful lifetime of the device is 5 (five) years with a duty cycle (that means, a power-on time) of 100%. A useful lifetime of 7 (seven) years can be guaranteed for a duty cycle of 70%. For both scenarios, it is assumed that the device will be used for calculations for approximately 5% of the maximum useful lifetime. Is it true? This is disqualification. Industrial equipment should work much longer, 15-20 years. It's not suitable for industrial equipment. It's good for ink toner cartridge. Best regards, Tom

2 years, 7 months

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Re: Infineon SLB 9670 lifetime

by Florian.Schreiner＠infineon.com

Hello Tom, thanks for your interest and to bring up the topics. I would like to provide some additional information on that. The document you mention is a datasheet, which only contains basic information. Some sections in particular to the integrated firmware is not included in the datasheet, because it is described in the full Databook document. You can get the databook via your distributor, who will grant you access on an Infineon portal for the distribution of such documents. There you will find also more recent documents from 2019. 1.1 Power management In chapter 4.3 of the document you can find another sleep mode, which is activated when CS# pin is inactive. This is an explicit power-down or standby mode that can be activated by the user. The very low current consumption shows, that in this mode almost everything inside the TPM is deactivated to reduce the power consumption to a very low value. 4.2 Functional Operational Range The SLB 9670 is the consumer variant of TPM, so therefore the lifetime is similar to consumer devices, which also have a much more limited lifetime (e.g. PC, workstation, tablet). There are other TPM variants for industrial - SLM 9670 - and for automotive - SLI 9670 -. The industrial SLM 9670 has a lifetime for 20 years, see https://www.infineon.com/cms/de/product/security-smart-card-solutions/opt... The datasheet is in the top right corner. I hope this helps to clarify these topics. Best regards, Florian

2 years, 7 months

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tpm2-tss v2.3.3

by Tadeusz Struk

Hello, A new bugfix release tpm2-tss v2.3.3 is out. https://github.com/tpm2-software/tpm2-tss/releases/tag/2.3.3 All changes and fixes are listed in the CHANGELOG.md file. Thanks, -- Tadeusz

2 years, 7 months

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tpm2 February 2020