tpm2_duplicate(1)

📦
version 5.8 · 10 versions
, in arch rolling

💖 tpm2_duplicate(1) 💖

okay bestie, so this is from the General Commands Manual — welcome to the tpm2_duplicate(1) glow-up ✨

🌸 NAME 🌸

tpm2_duplicate(1) — Duplicates a loaded object so that it may be used in a different hierarchy.

🎀 SYNOPSIS 🎀

tpm2_duplicate [OPTIONS]

🦋 DESCRIPTION 🦋

tpm2_duplicate(1) — okay so here's the tea 🫖: this tool duplicates a loaded object so that it may be used in a different hierarchy. The new parent key for the duplicate may be on the same or different TPM, or TPM_RH_NULL. Literally so flexible. Not me being obsessed with object portability 💅

✨ OPTIONS ✨

These options control the key importation process:

  • -G, --wrapper-algorithm=ALGORITHM — the symmetric algorithm to be used for the inner wrapper if -U is not used. Supports:
    • aes — AES 128 in CFB mode.
    • null — none. The key algorithm associated with the public parent if -U is used.
  • -G, --key-algorithm=ALGORITHM — the key algorithm associated with the public parent if -U is used. (yes bestie, -G shows up twice in this list — that's canon, don't come for me 🙈)
  • -i, --encryptionkey-in=FILE — specifies the filename of the symmetric key (128 bit data) to be used for the inner wrapper. Valid only when specified symmetric algorithm is not null.
  • -o, --encryptionkey-out=FILE — specifies the filename to store the symmetric key (128 bit data) that was used for the inner wrapper. Valid only when specified symmetric algorithm is not null and --input-key-file is not specified. The TPM generates the key in this case 👑
  • -C, --parent-context=OBJECT — the parent key object.
  • -U, --parent-public=FILE — specifies the file path to the public key of the parent object on the destination TPM. This should be a TPM2B_PUBLIC formatted file. This public key is used for the wrapping of a PEM or DER key which will be exported for a remote TPM.
  • -k, --private-key=FILE — specifies the file path to the external private key be encrypted for the remote TPM. This should be a PEM format private key.
  • -r, --private=FILE — specifies the file path to save the private portion of the duplicated object.

🔒 Protection Details

Objects that can move outside of TPM need to be protected (confidentiality and integrity). For instance, transient objects require that TPM protected data (key or seal material) be stored outside of the TPM. This is seen in tools like tpm2_create(1), where the -r option outputs this protected data. This blob contains the sensitive portions of the object. The sensitive portions of the object are protected by the parent object, using the parent's symmetric encryption details to encrypt the sensitive data and HMAC it. 🔐

In-depth details can be found in sections 23 of:

Notably Figure 20 is relevant, even though it's specifically referring to duplication blobs — the process is identical. no cap 🧚

If the output is from tpm2_duplicate(1), the output will be slightly different, as described fully in section 23.

  • -u, --public=FILE — specifies the file path to save the public portion of the duplicated object, if an external key is being duplicated.
  • -s, --encrypted-seed=FILE — the file to save the encrypted seed of the duplicated object.
  • -p, --auth=AUTH — the authorization value for the key, optional.
  • -L, --policy=FILE — the input policy file, optional.
  • -c, --key-context=OBJECT — the object to be duplicated. main character energy fr fr ⭐
  • -a, --attributes=ATTRIBUTES — the object attributes, optional. The default for created objects is:
TPMA_OBJECT_SIGN_ENCRYPT|TPMA_OBJECT_DECRYPT|TPMA_OBJECT_USERWITHAUTH
Note: If a policy is specified without an auth value then TPMA_OBJECT_USERWITHAUTH is turned down.
  • --cphash=FILE — file path to record the hash of the command parameters. This is commonly termed as cpHash.
NOTE: When this option is selected, the tool will not actually execute the command, it simply returns a cpHash. like it literally just hands you the hash and dips 💀

🌈 References 🌈

🎯 Context Object Format

The type of a context object — whether it is a handle or file name — is determined according to the following logic in-order:

  • If the argument is a file path, then the file is loaded as a restored TPM transient object.
  • If the argument is a prefix match on one of:
    • owner: the owner hierarchy
    • platform: the platform hierarchy
    • endorsement: the endorsement hierarchy
    • lockout: the lockout control persistent object
  • If the argument argument can be loaded as a number it will be treat as a handle, e.g. 0x81010013 and used directly._OBJECT_

🔑 Authorization Formatting

Authorization for use of an object in TPM2.0 can come in 3 different forms:

  1. Password
  2. HMAC
  3. Sessions
NOTE: "Authorizations default to the EMPTY PASSWORD when not specified".

For authentication with auth values, the tool commands implicitly generate an HMAC session. Thus passwords are not transmitted unencrypted. This does not apply to passwords defined for objects. In this case, an HMAC session should be used (see tpm2_startauthsession(1)).

🍓 Passwords

Passwords are interpreted in the following forms below using prefix identifiers.

Note: By default passwords are assumed to be in the string form when they do not have a prefix.

💜 String

A string password, specified by prefix str: or it's absence (raw string without prefix) is not interpreted, and is directly used for authorization.

🧚 Examples

foobar
str:foobar

🌸 Hex-string

A hex-string password, specified by prefix hex: is converted from a hexidecimal form into a byte array form, thus allowing passwords with non-printable and/or terminal un-friendly characters.

⭐ Example

hex:1122334455667788

🎀 File

A file based password, specified be prefix file: should be the path of a file containing the password to be read by the tool or a - to use stdin. Storing passwords in files prevents information leakage — passwords passed as options can be read from the process list or common shell history features. big yikes, protect ur secrets bestie 🫶

🌈 Examples

# to use stdin and be prompted
file:-

# to use a file from a path
file:path/to/password/file

# to echo a password via stdin:
echo foobar | tpm2_tool -p file:-

# to use a bash here-string via stdin:

tpm2_tool -p file:- <<< foobar

👑 Sessions

When using a policy session to authorize the use of an object, prefix the option argument with the session keyword. Then indicate a path to a session file that was created with tpm2_startauthsession(1). Optionally, if the session requires an auth value to be sent with the session handle (eg policy password), then append a + and a string as described in the Passwords section.

💅 Examples

To use a session context file called session.ctx.

session:session.ctx

To use a session context file called session.ctx AND send the authvalue mypassword.

session:session.ctx+mypassword

To use a session context file called session.ctx AND send the HEX authvalue 0x11223344.

session:session.ctx+hex:11223344

🦋 PCR Authorizations

You can satisfy a PCR policy using the pcr: prefix and the PCR minilanguage. The PCR minilanguage is as follows:

<pcr-spec>=<raw-pcr-file>

The PCR spec is documented in in the section "PCR bank specifiers".

The raw-pcr-file is an optional argument that contains the output of the raw PCR contents as returned by tpm2_pcrread(1).

🍓 PCR bank specifiers

✨ Examples

To satisfy a PCR policy of sha256 on banks 0, 1, 2 and 3 use a specifier of:

pcr:sha256:0,1,2,3

specifying AUTH.

✨ Algorithm Specifiers ✨

So like, every option that takes an algorithm? It speaks "nice-names" 💅. That's the whole vibe.

There are two big algorithm-specifier string classes: simple and complex. And no cap — only certain algorithms will be accepted by the TPM, depending on usage and conditions. It's giving "it depends" energy but fr fr.

🌸 Simple specifiers 🌸

These are strings with absolutely zero additional specification data. Just the name, that's it, main character energy ✨. When you're creating objects, the non-specified portions of an object are assumed to be defaults. And the list of known "Simple Specifiers" is right below, bestie 👇

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 🦋

Okay so when objects get specified for creation by the TPM, they've got numerous algorithms to populate in the public data. Think type, scheme, asymmetric details, key size, etc. — the whole fit 💅. The general format for specifying all this data is:

<type>:<scheme>:<symmetric-details>

👑 Type Specifiers 👑

This portion of the complex algorithm specifier is required — can't skip it, bestie. The remaining scheme and symmetric details will default based on the type specified and the type of 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 up is an optional field — you can literally just skip it, no stress 🫶.

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 (the default of all defaults, honestly iconic). Some take no arguments, and some take multiple arguments.

Hash Optional Scheme Specifiers

These scheme specifiers get 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. Like, none. Zero. 🙅

  • 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. (that trailing bit is just vibing there in the page, bestie — leave it be 🙈)

🔥 COMMON OPTIONS 🔥

This collection of options are common to many programs and provide information that many users may expect. It's the shared group chat of flags 👑

  • -h, --help=[man|no-man] — Display the tools 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 is set to yes or true. information many users may expect.
💀 Fair warning, bestie: -z sends a clear text password to the TPM. And if you're using auth values, a salted session should be used for authentication — that part's not a suggestion.

🌈 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. It's basically the aux cord to your TPM 🎧

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. Periodt.

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 — like, it's not subtle about it 🔍.

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. Build your own, slay 💅

💖 TCTI OPTIONS 💖

This collection of options are 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 default 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.
    • 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.

✨ EXAMPLES ✨

💅 Example-1: Duplicate a key created with a policy that allows for duplication 💅

okay bestie, this is the whole recipe for duplicating a key when the policy literally says duplication is allowed:

tpm2_startauthsession -S session.dat
tpm2_policycommandcode -S session.dat -L policy.dat TPM2_CC_Duplicate
tpm2_flushcontext session.dat

tpm2_createprimary -C o -g sha256 -G rsa -c primary.ctxt
tpm2_create -C primary.ctxt -g sha256 -G rsa -r key.prv -u key.pub  -c key.ctxt \
-L policy.dat -a "sensitivedataorigin|userwithauth|decrypt|sign"

tpm2_createprimary -C o -g sha256 -G ecc -c new_parent.ctxt

tpm2_startauthsession \--policy-session -S session.dat
tpm2_policycommandcode -S session.dat -L policy.dat TPM2_CC_Duplicate
tpm2_duplicate -C new_parent.ctxt -c key.ctxt -G null -p "session:session.dat" \
-r duprv.bin -s seed.dat
tpm2_flushcontext session.dat

🦋 Example-2: end-to-end transfer of an RSA key from TPM-A to TPM-B 🦋

As an end-to-end example, the following will transfer an RSA key generated on TPM-A to TPM-B. Main character energy: two TPMs, one key, no cap.

🌸 On TPM-B 🌸

Create a parent object that will be used to wrap/transfer the key.

tpm2_createprimary -C o -g sha256 -G rsa -c primary.ctx

tpm2_create  -C primary.ctx -g sha256 -G rsa \
-r new_parent.prv  -u new_parent.pub \
-a "restricted|sensitivedataorigin|decrypt|userwithauth"

Copy new_parent.pub to TPM-A.

💖 On TPM-A 💖

Create root object and auth policy allows duplication only.

tpm2_createprimary -C o -g sha256 -G rsa -c primary.ctx

tpm2_startauthsession -S session.dat

tpm2_policycommandcode -S session.dat -L dpolicy.dat TPM2_CC_Duplicate

tpm2_flushcontext session.dat

rm session.dat

Generate an RSA keypair on TPM-A that will be duplicated (note the passphrase is foo).

tpm2_create -C primary.ctx -g sha256 -G rsa -p foo -r key.prv \
-u key.pub  -L dpolicy.dat -a "sensitivedataorigin|userwithauth|decrypt|sign"

tpm2_load -C primary.ctx -r key.prv -u key.pub -c key.ctx

tpm2_readpublic -c key.ctx -o dup.pub

Test sign and encryption locally (so we can compare later that the same key was transferred).

echo "meet me at.." >file.txt
tpm2_rsaencrypt -c key.ctx  -o data.encrypted file.txt
tpm2_sign -c key.ctx -g sha256 -f plain -p foo -o sign.raw file.txt

Compare the signature hash (we will use this later to confirm the key was transferred to TPM-B):

sha256sum sign.raw

a1b4e3fbaa29e6e46d95cff498150b6b8e7d9fd21182622e8f5a3ddde257879e

Start an auth session and policy command to allow duplication.

tpm2_startauthsession --policy-session -S session.dat

tpm2_policycommandcode -S session.dat -L dpolicy.dat TPM2_CC_Duplicate

Load the new_parent.pub file transferred from TPM-B.

tpm2_loadexternal -C o -u new_parent.pub -c new_parent.ctx

Start the duplication.

tpm2_duplicate -C new_parent.ctx -c key.ctx -G null  \
-p "session:session.dat" -r dup.dpriv -s dup.seed

Copy the following files to TPM-B: dup.pub, dup.dpriv, dup.seed, and optionally data.encrypted just to test decryption.

🫶 On TPM-B 🫶

Start an auth,policy session.

tpm2_startauthsession --policy-session -S session.dat

tpm2_policycommandcode -S session.dat -L dpolicy.dat TPM2_CC_Duplicate

Load the context we used to transfer.

tpm2_flushcontext --transient-object

tpm2_load -C primary.ctx -u new_parent.pub -r new_parent.prv -c new_parent.ctx

Import the duplicated context against the parent we used.

tpm2_import -C new_parent.ctx -u dup.pub -i dup.dpriv \
-r dup.prv -s dup.seed -L dpolicy.dat

Load the duplicated key context.

tpm2_flushcontext --transient-object

tpm2_load -C new_parent.ctx -u dup.pub -r dup.prv -c dup.ctx

Test the imported key matches.

  • Sign:
echo "meet me at.." >file.txt

tpm2_sign -c dup.ctx -g sha256 -o sig.rss -p foo file.txt

dd if=sig.rss of=sign.raw bs=1 skip=6 count=256

Compare the signature file hash:

$ sha256sum sign.raw

a1b4e3fbaa29e6e46d95cff498150b6b8e7d9fd21182622e8f5a3ddde257879e
  • Decryption:
tpm2_flushcontext --transient-object

tpm2_rsadecrypt -p foo -c dup.ctx -o data.ptext data.encrypted

# cat data.ptext
meet me at..

🌈 Example-3: Exporting an OpenSSL RSA key for a remote TPM 🌈

To securely send an OpenSSL generated RSA key to a remote TPM such that only that remote TPM will be able to load it, and without exposing the private key to the host operating system on the remote machine:

  • On the destination TPM-B, create a primary context and read its public key, then send primary.pub to the source machine:
tpm2_createprimary -c primary.ctx
tpm2_readpublic -c primary.ctx -o primary.pub
  • On the source machine create the RSA private key and wrap it for the destination TPM's public key. Similar to tpm2_makecredential, this step should not require a TPM.
openssl genrsa -out rsa.pem
tpm2_duplicate -U primary.pub -G rsa -k rsa.pem -u rsa.pub -r rsa.dpriv -s rsa.seed
  • Send the rsa.pub, rsa.dpriv and rsa.seed to the destination TPM-B and import the files, which will decrypt them using the primary.ctx to produce rsa.priv, which can then be loaded and used as a TPM key:
tpm2_import -C primary.ctx -G rsa -i rsa.dpriv -s rsa.seed -u rsa.pub -r rsa.priv
tpm2_load -C primary.ctx -c rsa.ctx -u rsa.pub -r rsa.priv

🔥 Example-4: Exporting an HMAC key for a remote TPM and restrict it from further exports 🔥

This procedure will export an HMAC key created inside TPM-A only to TPM-B and with a policy that prevents TPM-B from allowing any further exports.

  • On the destination TPM-B, create a primary context:
tpm2_createprimary -C o -g sha256 -G rsa -c primary.ctx
tpm2_create  -C primary.ctx -g sha256 -G rsa -r new_parent.prv \
    -u new_parent.pub -a "fixedtpm|fixedparent|restricted|sensitivedataorigin|decrypt|userwithauth"

Copy new_parent.pub to TPM-A.

  • On source TPM-A

load the remote key and save its “name”.

tpm2_loadexternal -C o -u new_parent.pub -c new_parent.ctx -n new_parent.name

Create a primary object and a policy that restricts duplication to just TPM-B parent.

tpm2_createprimary -C o -g sha256 -G rsa -c primary.ctx
tpm2_startauthsession -S session.dat
tpm2_policyduplicationselect -S session.dat  -N new_parent.name -L dpolicy.dat
tpm2_flushcontext session.dat

Create an HMAC key with that policy.

tpm2_create -C primary.ctx -g sha256 -G hmac -r key.prv -u key.pub \
   -L dpolicy.dat -a "sensitivedataorigin|userwithauth|sign"

Load the key and save its “name”. Generate a test HMAC.

tpm2_load -C primary.ctx -r key.prv -u key.pub -c key.ctx
tpm2_readpublic -c key.ctx -n dupkey.name

export plain="foo"
echo -n $plain | tpm2_hmac -g sha256 -c key.ctx | xxd -p -c 256
   42a1fad918fa0e4cbea94d759da89ccdfac5a640672d0170f4930cafe14d179c

Start auth session for duplication with tpm2_policyduplicationselect.

tpm2_startauthsession --policy-session -S session.dat
tpm2_policyduplicationselect -S session.dat  -N new_parent.name \
   -L dpolicy.dat  -n dupkey.name

tpm2_duplicate -C new_parent.ctx -c key.ctx -G null \
   -p "session:session.dat" -r dup.dup -s dup.seed

Copy dup.dup dup.seed key.pub to TPM-B.

  • On destination TPM-B

Reload the original new parent and import the key.

tpm2_load -C primary.ctx -u new_parent.pub -r new_parent.prv -c new_parent.ctx

tpm2_import -C new_parent.ctx -u key.pub -i dup.dup  -r dup.prv -s dup.seed
tpm2_load -C new_parent.ctx -u key.pub -r dup.prv -c dup.ctx

Generate a sample HMAC.

export plain="foo"
echo -n $plain | tpm2_hmac -g sha256 -c dup.ctx | xxd -p -c 256
   42a1fad918fa0e4cbea94d759da89ccdfac5a640672d0170f4930cafe14d179c

💖 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. That's the whole vibe.

🌈 HELP 🌈

See the Mailing List.

🎀 License 🎀

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

Source/version: tpm2-tools. Page: tpm2_duplicate(1). Date: the footer didn’t print one, so I’m not inventing it, bestie — no extra lore today 💅✨

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