Hi Dimi, Sorry to bother you. By installing the latest version of tpm2-tools, encrypted communication is possible. Seal/unseal was possible as shown below. But I have one question. How can I detect if a MITM attack occurs during the seal/unseal process? After establishing a session, is there any way to get the EK certificate of that session? It seems that the tpm2_getekcertificate command can only get certificates created via the createek command. I'd like to know if the TPM I've made a session with is genuine. Seal: > tpm2_createprimary -c prim.ctx > tpm2_startauthsession --hmac-session -c prim.ctx -S sess.ctx > tpm2_create -Q -g sha256 -u seal.pub -r seal.priv -i temp.key -C prim.ctx -S sess.ctx > tpm2_load -Q -C prim.ctx -u seal.pub -r seal.priv -n seal.name -c sealctx > tpm2_evictcontrol -C o -c seal.ctx 0x81010001 > tpm2_flushcontext sess.ctx Unseal: > tpm2_startauthsession --hmac-session -c prim.ctx -S sess.ctx > tpm2_unseal -c seal.ctx -S sess.ctx -o out.key > tpm2_flushcontext sess.ctx Thanks & Regards, Joseph ------ Original Message ------ 보낸 사람: "Joseph Lee (ZeronsoftN)" <joseph(a)zeronsoftn.com&gt; 받는 사람: "Dimitar Tomov" <dimi(a)designfirst.ee&gt;; &quot;tpm2(a)lists.01.org&quot; < tpm2(a)lists.01.org&gt; 보낸 날짜: 2021-08-02 오전 6:27:36 제목: [tpm2] Re: Is the tpm2_create command safe against sniffing attacks? Hi Dimi, Thank you for your kind answer. Looking at the link you gave, I think I can get more ideas. I've been trying session encryption via tpm2-tools all weekend. But I haven't found a way to create an encrypted session in tpm2-tools yet. Maybe tpm2-tools doesn't support encrypted sessions? If this is clear, I will implement parameter encryption through tpm2-tools with referring to wolfTPM Thanks & Regards, Joseph ------ Original Message ------ 보낸 사람: "Dimitar Tomov" <dimi(a)designfirst.ee&gt; 받는 사람: &quot;tpm2(a)lists.01.org&quot; <tpm2(a)lists.01.org&gt;; "Joseph Lee (ZeronsoftN)" <joseph(a)zeronsoftn.com&gt; 보낸 날짜: 2021-08-02 오전 4:33:02 제목: [tpm2] Re: Is the tpm2_create command safe against sniffing attacks? Hi Joseph, TPM 2.0 offers Parameter Encryption capability and HMAC sessions as measures against Man-in-the-middle attacks Examples in wolfTPM demonstrate how to enable Parameter Encryption https://github.com/wolfSSL/wolfTPM/blob/b0a65e44b8a25be88b2f9ff4e35fbf083... There is also Keygen , Key import and Key loading examples with Parameter Encryption https://github.com/wolfSSL/wolfTPM/blob/b0a65e44b8a25be88b2f9ff4e35fbf083... Last week we discussed the Dolos Group story about a stolen laptop with TPM https://developers.tpm.dev/posts/15883726 If Parameter Encryption and HMAC session have been used, this story would have developed differently. Hope this helps. Dimi -- Founder of TPM.dev ------------------------------ *From:* Joseph Lee (ZeronsoftN) <joseph@zeronsoftncom <joseph(a)zeronsoftn.com&gt;&gt; *Sent:* Saturday, July 31, 2021 2:09 AM *To:* tpm2(a)lists.01.org <tpm2(a)lists.01.org&gt; *Subject:* [tpm2] Is the tpm2_create command safe against sniffing attacks? Hello, https://pulsesecurity.co.nz/articles/TPM-sniffing In this article, can see that communication with the TPM is vulnerable to sniffing if not careful. https://tpm2-software.github.io/2020/04/13/Disk-Encryption.html Is the disk encryption described in tpm2-software's blog safe against these attacks? 1. tpm2_createprimary -Q -C o -c prim.ctx 2. dd if=/dev/urandom bs=1 count=32 status=none | tpm2_create -Q -g sha256 -u seal.pub -r seal.priv -i- -C prim.ctx 3. tpm2_load -Q -C prim.ctx -u seal.pub -r seal.priv -n seal.name -c seal.ctx 4. tpm2_evictcontrol -C o -c seal.ctx 0x81010001 My question is: 1. Is there a tool in linux that can sniff communication with the current system's TPM? 2. How to encrypt communications if the methods described above are not secure? It seems that encryption is possible through tpm2_startauthsession , but I do not know how to apply it to tpm2_create . (The -S option simply did not work.) Thank you. _______________________________________________ tpm2 mailing list -- tpm2(a)lists.01.org To unsubscribe send an email to tpm2-leave(a)lists.01.org %(web_page_url)slistinfo%(cgiext)s/%(_internal_name)s

"Steven Clark" < davolfman(a)gmail.com&gt; wrote on 08/02/2021 01:26:56 PM: I think it may be an optional standard but my TPM has some certs permanently stored in nv-indices in the 0x1c0000x range that can be checked against the manufacturer cert.  I haven't learned how to leverage those into trusted parameter encryption keys yet but they should be able to verify there's a real TPM at the other end at the very least (and more if you learn to use them correctly). The EK certificates in NV are in theory optional, but every TPM I have encountered has them. Checking the certificate against the manufacturer's CA is a standard crypto library function. Once you have an authentic EK, create a salted session using the EK. Once you have the salted session, set the encrypt and/or decrypt bit when running the command. Underneath, there's some complicated crypto, but it's all hidden from the application. _______________________________________________ tpm2 mailing list -- tpm2(a)lists.01.org To unsubscribe send an email to tpm2-leave(a)lists.01.org %(web_page_url)slistinfo%(cgiext)s/%(_internal_name)s

tpm2_startauthsession -S session.ctx tpm2_policypcr -Q -S session.ctx -l sha256:0,2,4 -L pcrs.sha256.policy tpm2_flushcontext session.ctx tpm2_createprimary -C o -c tpm-primary.ctx tpm2_startauthsession --hmac-session -c tpm-primary.ctx -S session.ctx tpm2_create -g sha256 -u seal.pub -r seal.priv -i INPUT_KEY -C tpm-primary.ctx -S session.ctx -L pcrs.sha256.policy tpm2_load -C tpm-primary.ctx -u seal.pub -r seal.priv -n seal.name -c tpm-seal.ctx tpm2_evictcontrol -C o -c tpm-seal.ctx 0x81000002 tpm2_flushcontext session.ctx

tpm2_startauthsession --policy-session -S session.ctx tpm2_policypcr -S session.ctx -l sha256:0,2,4 tpm2_unseal -p session:session.ctx -c 0x81000002 -o OUTPUT_KEY tpm2_flushcontext session.ctx

I think it may be an optional standard but my TPM has some certs permanently stored in nv-indices in the 0x1c0000x range that can be checked against the manufacturer cert. I haven't learned how to leverage those into trusted parameter encryption keys yet but they should be able to verify there's a real TPM at the other end at the very least (and more if you learn to use them correctly).