tpm2_incrementalselftest(1)

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💅 tpm2_incrementalselftest(1) 💅 (General Commands Manual)

✨ NAME ✨

tpm2_incrementalselftest(1) — request testing of specified algorithm list 💖

🌸 SYNOPSIS 🌸

tpm2_incrementalselftest [OPTIONS] ALG_SPEC_LIST

🦋 DESCRIPTION 🦋

Okay bestie, so tpm2_incrementalselftest(1) asks the TPM to perform testing on the algorithm you specify, and then it prints a list of algorithms scheduled to be tested OR algorithms that remain to be tested but are not scheduled. 💅

The main-character reason this command exists? It helps reduce delays that might happen on cryptographic operations, because the TPM must test the algorithm prior to using it. 🔥

🎀 ALG_SPEC_LIST 🎀

This is a space-separated list of algorithm suite to be tested. Algorithms should follow the “formatting standards” — see the section “Algorithm Specifiers”. Also, see the section “Supported Hash Algorithms” for a list of supported hash algorithms. ✨

If ALG_SPEC_LIST is left empty, tpm2_incrementalselftest(1) will return the list of algorithms left to be tested. Please note that in this case these algorithms are NOT scheduled to be tested. 🫶

If ALG_SPEC_LIST is not empty, tpm2_incrementalselftest(1) will return the list of algorithms that remains to be tested. This list contains algorithms scheduled for testing AND algorithms that remains to be tested and not yet scheduled. This can occur for instance if all AES mode have not been already tested yet. 👑

🌈 Output 🌈

The list of algorithms to be tested (implying scheduled) or remain to be tested (not scheduled) is also printed in YAML format. 🍓

If none of the specified algorithm is printed, that means both that they are already tested AND that these algorithms won’t be tested again. 💀

💖 OPTIONS 💖

This tool accepts no tool specific options. Literally none, bestie. 🎀

📚 References 📚

🧮 Algorithm Specifiers 🧮

Options that take algorithms support “nice-names”. 💅

There are two major algorithm specification string classes: simple and complex. Only certain algorithms will be accepted by the TPM, based on usage and conditions. ✨

Simple specifiers

These are strings with no additional specification data. When creating objects, non-specified portions of an object are assumed to defaults. You can find the list of known “Simple Specifiers” below. 🦋

Asymmetric

  • rsa
  • ecc

Symmetric

  • aes
  • camellia
  • sm4

Hashing Algorithms

  • sha1
  • sha256
  • sha384
  • sha512
  • sm3_256
  • sha3_256
  • sha3_384
  • sha3_512

Keyed Hash

  • hmac
  • xor

Signing Schemes

  • rsassa
  • rsapss
  • ecdsa
  • ecdaa
  • ecschnorr
  • sm2

Asymmetric Encryption Schemes

  • oaep
  • rsaes
  • ecdh

Modes

  • ctr
  • ofb
  • cbc
  • cfb
  • ecb

Misc

  • null

Complex Specifiers

Objects, when specified for creation by the TPM, have numerous algorithms to populate in the public data. Things like type, scheme and asymmetric details, key size, etc. Below is the general format for specifying this data: <type>:<scheme>:<symmetric-details> 🌟

Type Specifiers

This portion of the complex algorithm specifier is required. The remaining scheme and symmetric details will default based on the type specified and the type of the object being created. 💖

  • aes — Default AES: aes128
  • aes128<mode> — 128 bit AES with optional mode (ctr|ofb|cbc|cfb|ecb). If mode is not specified, defaults to null.
  • aes192<mode> — Same as aes128<mode>, except for a 192 bit key size.
  • aes256<mode> — Same as aes128<mode>, except for a 256 bit key size.
  • sm4 — Default SM4: sm4128
  • sm4128 or sm4_128 <mode> — 128 bit SM4 with optional mode (ctr|ofb|cbc|cfb|ecb). If mode is not specified, defaults to null.
  • ecc — Elliptical Curve, defaults to ecc256.
  • ecc192 or ecc_nist_p192 — 192 bit ECC NIST curve
  • ecc224 or ecc_nist_p224 — 224 bit ECC NIST curve
  • ecc256 or ecc_nist_p256 — 256 bit ECC NIST curve
  • ecc384 or ecc_nist_p384 — 384 bit ECC NIST curve
  • ecc521 or ecc_nist_p521 — 521 bit ECC NIST curve
  • ecc_sm2 or ecc_sm2_p256 — 256 bit SM2 curve
  • rsa — Default RSA: rsa2048
  • rsa1024 — RSA with 1024 bit keysize.
  • rsa2048 — RSA with 2048 bit keysize.
  • rsa3072 — RSA with 3072 bit keysize.
  • rsa4096 — RSA with 4096 bit keysize.

Scheme Specifiers

Next, is an optional field — it can be skipped. 👀

Schemes are usually Signing Schemes or Asymmetric Encryption Schemes. Most signing schemes take a hash algorithm directly following the signing scheme. If the hash algorithm is missing, it defaults to sha256. Some take no arguments, and some take multiple arguments. 💫

Hash Optional Scheme Specifiers

These scheme specifiers are followed by a dash and a valid hash algorithm. For example: oaep-sha256. 🌸

  • oaep
  • ecdh
  • rsassa
  • rsapss
  • ecdsa
  • ecschnorr
  • sm2

Multiple Option Scheme Specifiers

This scheme specifier is followed by a count (max size UINT16) then followed by a dash(-) and a valid hash algorithm.

  • ecdaa

For example, ecdaa4-sha256. If no count is specified, it defaults to 4. 🔢

No Option Scheme Specifiers

This scheme specifier takes NO arguments.

  • rsaes

Symmetric Details Specifiers

This field is optional, and defaults based on the type of object being created and it’s attributes. Generally, any valid Symmetric specifier from the Type Specifiers list should work. If not specified, an asymmetric objects symmetric details defaults to aes128cfb. 🎀

Examples

Create an rsa2048 key with an rsaes asymmetric encryption scheme

tpm2_create -C parent.ctx -G rsa2048:rsaes -u key.pub -r key.priv

Create an ecc256 key with an ecdaa signing scheme with a count of 4 and sha384 hash

/tpm2_create -C parent.ctx -G ecc256:ecdaa4-sha384 -u key.pub -r
key.priv cryptographic algorithms ALGORITHM.

💜 COMMON OPTIONS 💜

This collection of options are common to many programs and provide information that many users may expect. 🫶

  • -h, --help=[man|no-man] — Display the tool’s manpage. By default, it attempts to invoke the manpager for the tool, however, on failure will output a short tool summary. This is 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 if specified, or the manpager fails, the short options will be output to stdout.

To successfully use the manpages feature requires the manpages 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 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. information many users may expect.

🦋 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 🌈

okay bestie so this lil collection of options is how you set up the different known TCTI modules, and there's a few of them, so buckle up 💅

  • device — for the device TCTI, you can tell it which TPM character device file to use. the default is /dev/tpm0, iconic behaviour honestly.

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

  • mssim — for the mssim TCTI, you can specify the domain name or IP address and the port number that the simulator is using. the defaults are 127.0.0.1 and 2321, no cap.

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 literally just a series of simple key value pairs, separated by a , character. each key and value string gets separated by a = character. slay.

the TCTI abrmd supports two keys, and yes there's only two:

  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) — and it's limited to session and system, so don't get creative 🎀

so if you wanna specify the tabrmd tcti name plus a config string of bus_name=com.example.FooBar, you'd do:

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

and if you wanna specify the default (abrmd) tcti plus a config string of bus_type=session:

--tcti:bus_type=session
NOTE: abrmd and tabrmd are synonymous. it's giving "two names, one vibe" fr fr. (this is the part where the original text about the various known TCTI modules trails off — that's just how it is, bestie, we don't gatekeep.) 🦋

✨ EXAMPLES ✨

Request testing of RSA algorithm

tpm2_incrementalselftest rsa

Request testing of multiple algorithms

tpm2_incrementalselftest rsa ecc xor aes cbc

look at that, five whole algorithms in one go, main character energy 👑

🌸 NOTES 🌸

so the algorithm suite you specify can imply either testing the combination or the complete suite — and that depends on the TPM manufacturer implementation. it's not you, it's them 😭

for example: one TPM might only test AES with CTR mode if “aes ctr” is specified. an other might also test the complete AES mode list AND test ctr mode. same command, different energy. iykyk.

also important, bestie: if an algorithm has already been tested, this command won't permit re-executing the test. no do-overs 🫶 the only way to force re-testing is by issuing tpm2_selftest(1) in full-test mode enabled. that's the only key to that door.

💜 Returns 💜

tools can return any of the following codes, and yes you should actually check them:

  • 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 — that's where you go, that's where the lore lives.

🧚 HELP 🧚

See the Mailing List.

⭐ License ⭐

this work is licensed under the Creative Commons Attribution 4.0 International License (CC BY 4.0). go forth, share, attribute, thrive ✨

aaaand that's the whole page, bestie!! this was tpm2-tools, the tpm2_incrementalselftest(1) manual page — and the original page drops its date down at the bottom next to the source/version line, so consider this your cute lil sign-off where that footer would be 🎀💖 you're gonna do amazing incremental self-tests, i believe in you, periodt. 💅🌸

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