tpm2_getekcertificate(1)

📦
version 5.8 · 10 versions
, in arch rolling

💖 tpm2_getekcertificate(1) 💖

hiii bestie 🫶 so this is the manual page for tpm2_getekcertificate(1) — it lives in the General Commands Manual section, and it's literally named after the tool itself, which honestly is kind of iconic of it 💅

🎀 NAME 🎀

tpm2_getekcertificate(1) — Retrieve the Endorsement key Certificate.

🦋 SYNOPSIS 🦋

tpm2_getekcertificate [OPTIONS] [ARGUMENT]

🌸 DESCRIPTION 🌸

tpm2_getekcertificate(1) — it retrieves the endorsement key certificate, periodt. ✨ And here's the tea: that certificate is chilling in one of two places — either on the TCG specified TPM NV indices, OR on the TPM manufacturer's endorsement certificate hosting server. Which one it goes for depends on the conditions below, so pay attention bestie 📝

  1. NV-Index:

This is the default search location when ARGUMENT is not specified. 🏠

  1. Intel-EK-certificate-server:

This is the search location when the EK certificate could not be found in the NV index AND the tpmEPSgenerated bit is CLEAR AND the manufacturer is INTC.

  1. Intel-EK-Re-certification-server:

This is the search location when the EK certificate could not be found in the NV index AND the tpmEPSgenerated bit is SET AND the manufacturer is INTC.

Note:

In this operation information is provided regarding additional software to be run as part of the re-provisioning/re-certification service.

After the re-provisioning/recertification process is complete, EK certificates can be read from the NV indexes by running another instance of tpm2_getekcertificate. 🔁

  1. Generic or other EK-certificate-server:

This is the search location when ARGUMENT specifies the EK certificate web hosting address. 🌐

💅 OPTIONS 💅

  • -o, --ek-certificate=FILE or STDOUT — the file where you save the Endorsement key certificate. When EK certificates are found in the TPM NV indices, you can specify this option additional times to save the RSA and ECC EK certificates in order 🔢. The tool will warn you if additional EK certificates are found on the TPM NV indices and only a single output file is specified ⚠️. And if the option isn't specified at all, all the EK certificates retrieved — either from the manufacturer web hosting or from the TPM NV indices — are output to stdout 📤.
  • -X, --allow-unverified — tells it to attempt connecting with the TPM manufacturer provisioning server without verifying the server certificate. This option is irrelevant when EK certificates are found on the TPM NV indices.
WARNING: this option should be used only on platforms with older CA certificates. fr fr, don't just leave this on 🙈
  • -u, --ek-public=FILE — specifies the file path for the endorsement key public portion in tss format 🔑.
  • -x, --offline — flags the tool to operate in an offline mode. In that mode, the certificates can be retrieved for a supplied EK public that does not belong to the platform the tool is run on. Super useful in factory provisioning of multiple platforms that are not individually connected to the Internet 🌍. In such a scenario a single Internet facing provisioning server can utilize this tool in this mode. Heads up: this forces the tool to not look for the EK certificates on the NV indices 🚫.
  • –raw — flags the tool to output the EK certificate as is received from the source: NV/Web-Hosting 📦.
  • -E, --encoding=ENCODING — specifies the encoding format to use explicitly. Normally, the default method is the one used by Intel unless an AMD fTPM is detected, in which case the AMD-specific encoding is used. Use a for AMD and i for Intel 🔤.
  • -t, --x509-trunc — flags the tool to parse certificates read from TPM NV indices with a X509 parser, and truncate the trailing data before output ✂️. Useful when dealing with TPMs that output certificates with trailing data padded to a fixed length.
  • ARGUMENT — the command line argument that specifies the URL address for the EK certificate portal. This forces the tool to not look for the EK certificates on the NV indices 🚫.

References

(yes bestie, this subsection is literally just sitting there empty in the original — no refs listed, so there's nothing to summarize 💀)

🌈 COMMON OPTIONS 🌈

This collection of options is common to many programs and provides information that many users may expect. iykyk 🫶

  • -h, --help=[man|no-man] — Display the tool's manpage 📖. By default it attempts to invoke the manpager for the tool, but on failure it will output a short tool summary. That's the same behavior if the “man” option argument is specified — however, if explicit “man” is requested, the tool will provide errors from man on stderr. If the “no-man” option is specified, or the manpager fails, the short options will be output to stdout.

To successfully use the manpages feature, the manpages need to be installed or on MANPATH — see man(1) for more details 👀

  • -v, --version — Display version information for this tool, supported tctis, and exit ✌️
  • -V, --verbose — Increase the information that the tool prints to the console during its execution 🗣️. When using this option, the file and line number are printed.
  • -Q, --quiet — Silence normal tool output to stdout 🤫
  • -Z, --enable-errata — Enable the application of errata fixups. Useful if an errata fixup needs to be applied to commands sent to the TPM. Defining the environment TPM2TOOLS_ENABLE_ERRATA is equivalent 🔧
  • -z, --pwd-session — Use a password session instead of a HMAC session for authentication. A clear text password is passed to the TPM to authorize the action. This option can be used to avoid problems when unsalted sessions are used in OpenSSL FIPS mode. If auth values are used, a salted session should be used for authentication 🔐
  • -R, --autoflush — Enable autoflush for transient objects created by the command. If a parent object is loaded from a context file, also the transient parent object will be flushed 🚽. Autoflush can also be activated if the environment variable TPM2TOOLS_AUTOFLUSH is set to yes or true. (the original page also says "information many users may expect." right at the end of this bullet — yeah, that's just how it ends 😭)

TCTI Configuration

The TCTI, or “Transmission Interface,” is the communication mechanism with the TPM 🔌. TCTIs can be changed for communication with TPMs across different mediums.

To control the TCTI, the tools respect:

  1. The command line option -T or --tcti
  2. The environment variable: TPM2TOOLS_TCTI
Note: the command line option always overrides the environment variable 👑

The current known TCTIs are:

  • tabrmd — The resource manager, called tabrmd. Note that tabrmd and abrmd as a tcti name are synonymous.
  • mssim — Typically used for communicating to the TPM software simulator 🧪.
  • device — Used when talking directly to a TPM device file.
  • none — Do not initalize a connection with the TPM. Some tools allow for off-tpm options and thus support not using a TCTI. Tools that do not support it will error when attempted to be used without a TCTI connection. Does not support ANY options and MUST BE presented as the exact text of "none" 🚫.

The arguments to either the command line option or the environment variable are in the form:

<tcti-name>:<tcti-option-config>

Specifying an empty string for either the <tcti-name> or <tcti-option-config> results in the default being used for that portion respectively ✨.

TCTI Defaults

When a TCTI is not specified, the default TCTI is searched for using dlopen(3) semantics 🔎. The tools will search for tabrmd, device and mssim TCTIs IN THAT ORDER and USE THE FIRST ONE FOUND. You can query what TCTI will be chosen as the default by using the -v option to print the version information. The default-tcti key-value pair will indicate which of the aforementioned TCTIs is the default 👑.

Custom TCTIs

Any TCTI that implements the dynamic TCTI interface can be loaded 🧩. The tools internally use dlopen(3), and the raw tcti-name value is used for the lookup. Thus, this could be a path to the shared library, or a library name as understood by dlopen(3) semantics.

🔥 TCTI OPTIONS 🔥

This collection of options is used to configure the various known TCTI modules available:

  • device — For the device TCTI, the TPM character device file for use by the device TCTI can be specified. The default is /dev/tpm0 💾

Example: -T device:/dev/tpm0 or export TPM2TOOLS_TCTI=“device:/dev/tpm0”

  • mssim — For the mssim TCTI, the domain name or IP address and port number used by the simulator can be specified. The defaults are 127.0.0.1 and 2321 🌐

Example: -T mssim:host=localhost,port=2321 or export TPM2TOOLS_TCTI=“mssim:host=localhost,port=2321”

  • abrmd — For the abrmd TCTI, the configuration string format is a series of simple key value pairs separated by a , character. Each key and value string are separated by a = character 🔑
    • The TCTI abrmd supports two keys:
      1. bus_name : The name of the tabrmd service on the bus (a string).
      2. bus_type : The type of the dbus instance (a string) limited to session and system.

Specify the tabrmd tcti name and a config string of bus_name=com.example.FooBar:

\--tcti=tabrmd:bus_name=com.example.FooBar

Specify the default (abrmd) tcti and a config string of bus_type=session:

\--tcti:bus_type=session
NOTE: abrmd and tabrmd are synonymous. the various known TCTI modules. (that trailing fragment is just how the original ends that note, bestie — I'm not hiding anything from you 😭)

📝 NOTES 📝

When the verbose option is specified, additional curl debugging information is provided by setting the curl mode verbose — see https://curl.haxx.se/libcurl/c/CURLOPT_VERBOSE.html for more information 🔍

🍓 EXAMPLES 🍓

Retrieve EK certificate from TPM manufacturer backend by supplying EK public.

tpm2_createek -G rsa -u ek.pub -c key.ctx

tpm2_getekcertificate -X -o ECcert.bin -u ek.pub \
https://tpm.manufacturer.com/ekcertserver/

Retrieve EK certificate from Intel backend if certificate not found on NV.

tpm2_createek -G rsa -u ek.pub -c key.ctx

tpm2_getekcertificate -X -o ECcert.bin -u ek.pub

Retrieve EK certificate from Intel backend for an offline platform.

tpm2_getekcertificate -X -x -o ECcert.bin -u ek.pub

Retrieve EK certificate from TPM NV indices only, fail otherwise.

tpm2_getekcertificate -o ECcert.bin

Retrieve EK certificate from TPM NV indices for an EK public key, fail otherwise.

tpm2_createek -G ecc384 -u ek_ecc384.pub -c ek_ecc384.ctx
tpm2_getekcertificate -o ek_ecc384.cert -u ek_ecc384.pub

Retrieve multiple EK certificates from TPM NV indices only, fail otherwise.

tpm2_getekcertificate -o RSA_EK_cert.bin -o ECC_EK_cert.bin

✅ Returns ✅

Tools can return any of the following codes:

  • 0 — Success 🎉
  • 1 — General non-specific error.
  • 2 — Options handling error.
  • 3 — Authentication error.
  • 4 — TCTI related error.
  • 5 — Non supported scheme. Applicable to tpm2_testparams.

🐛 BUGS 🐛

Github Issues 🫶

🆘 HELP 🆘

See the Mailing List 📬

👑 License 👑

This work is licensed under the Creative Commons Attribution 4.0 International License (CC BY 4.0).

and that's the whole page, bestie ✨ this one ships as part of tpm2-tools, and the page itself is tpm2_getekcertificate(1) — go get those certificates, ily, drink water 💜🎀🦋

📦 where this page comes from