.\" Automatically generated by Pandoc 2.5
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.TH "tpm2_sign" "1" "" "tpm2\-tools" "General Commands Manual"
.hy
.SH NAME
.PP
\f[B]tpm2_sign\f[R](1) \- Sign a hash or message using the TPM.
.SH SYNOPSIS
.PP
\f[B]tpm2_sign\f[R] [\f[I]OPTIONS\f[R]] [\f[I]ARGUMENT\f[R]]
.SH DESCRIPTION
.PP
\f[B]tpm2_sign\f[R](1) \- Generates signature of specified message or
message\-digest using the specified symmetric or asymmetric signing key.
.PP
When signing a message, \f[B]tpm2_sign\f[R] utility first calculates the
digest of the message similar to the \f[B]tpm2_hash\f[R] command.
It also generates a validation ticket under TPM2_RH_NULL or
TPM2_RH_OWNER hierarchies respectively for unrestricted or the
restricted signing keys.
.PP
While signing messages is a provision in this tool it is recommended to
use the \f[B]tpm2_hash\f[R] tool first and pass the digest and
validation ticket.
.PP
NOTE: If the signing key is a restricted signing key, then validation
and digest must be provided via the \f[B]\-t\f[R] input.
The ticket indicates that the TPM performed the hash of the message.
.SH OPTIONS
.IP \[bu] 2
\f[B]\-c\f[R], \f[B]\-\-key\-context\f[R]=\f[I]OBJECT\f[R]:
.RS 2
.PP
Context object pointing to the the key used for signing.
Either a file or a handle number.
See section \[lq]Context Object Format\[rq].
.RE
.IP \[bu] 2
\f[B]\-p\f[R], \f[B]\-\-auth\f[R]_AUTH_:
.RS 2
.PP
Optional authorization value to use the key specified by \f[B]\-c\f[R].
Authorization values should follow the \[lq]authorization formatting
standards\[rq], see section \[lq]Authorization Formatting\[rq].
.RE
.IP \[bu] 2
\f[B]\-g\f[R], \f[B]\-\-hash\-algorithm\f[R]=\f[I]ALGORITHM\f[R]:
.RS 2
.PP
The hash algorithm used to digest the message.
Algorithms should follow the \[lq]formatting standards\[rq], see section
\[lq]Algorithm Specifiers\[rq].
Also, see section \[lq]Supported Hash Algorithms\[rq] for a list of
supported hash algorithms.
.RE
.IP \[bu] 2
\f[B]\-s\f[R], \f[B]\-\-scheme\f[R]=\f[I]ALGORITHM\f[R]:
.RS 2
.PP
The signing scheme used to sign the message.
Optional.
.PP
Signing schemes should follow the \[lq]formatting standards\[rq], see
section \[lq]Algorithm Specifiers\[rq].
.PP
If specified, the signature scheme must match the key type.
If left unspecified, a default signature scheme for the key type will be
used.
.RE
.IP \[bu] 2
\f[B]\-d\f[R], \f[B]\-\-digest\f[R]:
.RS 2
.PP
Indicate that \f[I]FILE\f[R] is a file containing the digest of the
message.
When this option and \f[B]\-t\f[R] is specified, a warning is generated
and the \f[B]validation ticket (\-t) is ignored\f[R].
You cannot use this option to sign a digest against a restricted signing
key.
.RE
.IP \[bu] 2
\f[B]\-t\f[R], \f[B]\-\-ticket\f[R]=\f[I]FILE\f[R]:
.RS 2
.PP
The ticket file, containing the validation structure, optional.
.RE
.IP \[bu] 2
\f[B]\-o\f[R], \f[B]\-\-signature\f[R]=\f[I]FILE\f[R]:
.RS 2
.PP
The signature file, records the signature structure.
.RE
.IP \[bu] 2
\f[B]\-f\f[R], \f[B]\-\-format\f[R]=\f[I]FORMAT\f[R]:
.RS 2
.PP
Format selection for the signature output file.
See section \[lq]Signature Format Specifiers\[rq].
.RE
.IP \[bu] 2
\f[B]\-\-cphash\f[R]=\f[I]FILE\f[R]
.RS 2
.PP
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.
.RE
.IP \[bu] 2
\f[B]\-\-commit\-index\f[R]=\f[I]NATURALNUMBER\f[R]
.RS 2
.PP
The commit counter value to determine the key index to use in an ECDAA
signing scheme.
The default counter value is 0.
.RE
.IP \[bu] 2
\f[B]ARGUMENT\f[R] the command line argument specifies the file data for
sign.
.SS References
.SH Context Object Format
.PP
The type of a context object, whether it is a handle or file name, is
determined according to the following logic \f[I]in\-order\f[R]:
.IP \[bu] 2
If the argument is a file path, then the file is loaded as a restored
TPM transient object.
.IP \[bu] 2
If the argument is a \f[I]prefix\f[R] match on one of:
.RS 2
.IP \[bu] 2
owner: the owner hierarchy
.IP \[bu] 2
platform: the platform hierarchy
.IP \[bu] 2
endorsement: the endorsement hierarchy
.IP \[bu] 2
lockout: the lockout control persistent object
.RE
.IP \[bu] 2
If the argument argument can be loaded as a number it will be treat as a
handle, e.g.\ 0x81010013 and used directly._OBJECT_.
.SH Authorization Formatting
.PP
Authorization for use of an object in TPM2.0 can come in 3 different
forms: 1.
Password 2.
HMAC 3.
Sessions
.PP
\f[B]NOTE:\f[R] \[lq]Authorizations default to the \f[B]EMPTY
PASSWORD\f[R] when not specified\[rq].
.SS Passwords
.PP
Passwords are interpreted in the following forms below using prefix
identifiers.
.PP
\f[B]Note\f[R]: By default passwords are assumed to be in the string
form when they do not have a prefix.
.SS String
.PP
A string password, specified by prefix \[lq]str:\[rq] or it\[cq]s
absence (raw string without prefix) is not interpreted, and is directly
used for authorization.
.SS Examples
.IP
.nf
\f[C]
foobar
str:foobar
\f[R]
.fi
.SS Hex\-string
.PP
A hex\-string password, specified by prefix \[lq]hex:\[rq] is converted
from a hexidecimal form into a byte array form, thus allowing passwords
with non\-printable and/or terminal un\-friendly characters.
.SS Example
.IP
.nf
\f[C]
hex:0x1122334455667788
\f[R]
.fi
.SS File
.PP
A file based password, specified be prefix \[lq]file:\[rq] should be the
path of a file containing the password to be read by the tool or a
\[lq]\-\[rq] 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.
.SS Examples
.IP
.nf
\f[C]
# 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
\f[R]
.fi
.SS Sessions
.PP
When using a policy session to authorize the use of an object, prefix
the option argument with the \f[I]session\f[R] 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 \f[B]Passwords\f[R] section.
.SS Examples
.PP
To use a session context file called \f[I]session.ctx\f[R].
.IP
.nf
\f[C]
session:session.ctx
\f[R]
.fi
.PP
To use a session context file called \f[I]session.ctx\f[R] \f[B]AND\f[R]
send the authvalue mypassword.
.IP
.nf
\f[C]
session:session.ctx+mypassword
\f[R]
.fi
.PP
To use a session context file called \f[I]session.ctx\f[R] \f[B]AND\f[R]
send the \f[I]HEX\f[R] authvalue 0x11223344.
.IP
.nf
\f[C]
session:session.ctx+hex:11223344
\f[R]
.fi
.SS PCR Authorizations
.PP
You can satisfy a PCR policy using the \[lq]pcr:\[rq] prefix and the PCR
minilanguage.
The PCR minilanguage is as follows:
\f[C]<pcr\-spec>=<raw\-pcr\-file>\f[R]
.PP
The PCR spec is documented in in the section \[lq]PCR bank
specifiers\[rq].
.PP
The \f[C]raw\-pcr\-file\f[R] is an \f[B]optional\f[R] argument that
contains the output of the raw PCR contents as returned by
\f[I]tpm2_pcrread(1)\f[R].
.PP
PCR bank specifiers (pcr.md)
.SS Examples
.PP
To satisfy a PCR policy of sha256 on banks 0, 1, 2 and 3 use a specifier
of:
.IP
.nf
\f[C]
pcr:sha256:0,1,2,3
\f[R]
.fi
.PP
specifying \f[I]AUTH\f[R].
.SH Algorithm Specifiers
.PP
Options that take algorithms support \[lq]nice\-names\[rq].
.PP
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.
.SS Simple specifiers
.PP
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 \[lq]Simple Specifiers Below\[rq].
.SS Asymmetric
.IP \[bu] 2
rsa
.IP \[bu] 2
ecc
.SS Symmetric
.IP \[bu] 2
aes
.IP \[bu] 2
camellia
.SS Hashing Algorithms
.IP \[bu] 2
sha1
.IP \[bu] 2
sha256
.IP \[bu] 2
sha384
.IP \[bu] 2
sha512
.IP \[bu] 2
sm3_256
.IP \[bu] 2
sha3_256
.IP \[bu] 2
sha3_384
.IP \[bu] 2
sha3_512
.SS Keyed Hash
.IP \[bu] 2
hmac
.IP \[bu] 2
xor
.SS Signing Schemes
.IP \[bu] 2
rsassa
.IP \[bu] 2
rsapss
.IP \[bu] 2
ecdsa
.IP \[bu] 2
ecdaa
.IP \[bu] 2
ecschnorr
.SS Asymmetric Encryption Schemes
.IP \[bu] 2
oaep
.IP \[bu] 2
rsaes
.IP \[bu] 2
ecdh
.SS Modes
.IP \[bu] 2
ctr
.IP \[bu] 2
ofb
.IP \[bu] 2
cbc
.IP \[bu] 2
cfb
.IP \[bu] 2
ecb
.SS Misc
.IP \[bu] 2
null
.SS Complex Specifiers
.PP
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:
\f[C]<type>:<scheme>:<symmetric\-details>\f[R]
.SS Type Specifiers
.PP
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.
.IP \[bu] 2
aes \- Default AES: aes128
.IP \[bu] 2
aes128\f[C]<mode>\f[R] \- 128 bit AES with optional mode
(\f[I]ctr\f[R]|\f[I]ofb\f[R]|\f[I]cbc\f[R]|\f[I]cfb\f[R]|\f[I]ecb\f[R]).
If mode is not specified, defaults to \f[I]null\f[R].
.IP \[bu] 2
aes192\f[C]<mode>\f[R] \- Same as aes128\f[C]<mode>\f[R], except for a
192 bit key size.
.IP \[bu] 2
aes256\f[C]<mode>\f[R] \- Same as aes128\f[C]<mode>\f[R], except for a
256 bit key size.
.IP \[bu] 2
ecc \- Elliptical Curve, defaults to ecc256.
.IP \[bu] 2
ecc192 \- 192 bit ECC
.IP \[bu] 2
ecc224 \- 224 bit ECC
.IP \[bu] 2
ecc256 \- 256 bit ECC
.IP \[bu] 2
ecc384 \- 384 bit ECC
.IP \[bu] 2
ecc521 \- 521 bit ECC
.IP \[bu] 2
rsa \- Default RSA: rsa2048
.IP \[bu] 2
rsa1024 \- RSA with 1024 bit keysize.
.IP \[bu] 2
rsa2048 \- RSA with 2048 bit keysize.
.IP \[bu] 2
rsa4096 \- RSA with 4096 bit keysize.
.SS Scheme Specifiers
.PP
Next, is an optional field, it can be skipped.
.PP
Schemes are usually \f[B]Signing Schemes\f[R] or \f[B]Asymmetric
Encryption Schemes\f[R].
Most signing schemes take a hash algorithm directly following the
signing scheme.
If the hash algorithm is missing, it defaults to \f[I]sha256\f[R].
Some take no arguments, and some take multiple arguments.
.SS Hash Optional Scheme Specifiers
.PP
These scheme specifiers are followed by a dash and a valid hash
algorithm, For example: \f[C]oaep\-sha256\f[R].
.IP \[bu] 2
oaep
.IP \[bu] 2
ecdh
.IP \[bu] 2
rsassa
.IP \[bu] 2
rsapss
.IP \[bu] 2
ecdsa
.IP \[bu] 2
ecschnorr
.SS Multiple Option Scheme Specifiers
.PP
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.
.SS No Option Scheme Specifiers
.PP
This scheme specifier takes NO arguments.
* rsaes
.SS Symmetric Details Specifiers
.PP
This field is optional, and defaults based on the \f[I]type\f[R] of
object being created and it\[cq]s attributes.
Generally, any valid \f[B]Symmetric\f[R] specifier from the \f[B]Type
Specifiers\f[R] list should work.
If not specified, an asymmetric objects symmetric details defaults to
\f[I]aes128cfb\f[R].
.SS Examples
.SS Create an rsa2048 key with an rsaes asymmetric encryption scheme
.PP
\f[C]tpm2_create \-C parent.ctx \-G rsa2048:rsaes \-u key.pub \-r key.priv\f[R]
.SS Create an ecc256 key with an ecdaa signing scheme with a count of 4 and sha384 hash
.PP
\f[C]/tpm2_create \-C parent.ctx \-G ecc256:ecdaa4\-sha384 \-u key.pub \-r key.priv\f[R]
cryptographic algorithms \f[I]ALGORITHM\f[R].
.SH COMMON OPTIONS
.PP
This collection of options are common to many programs and provide
information that many users may expect.
.IP \[bu] 2
\f[B]\-h\f[R], \f[B]\-\-help=[man|no\-man]\f[R]: 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 \[lq]man\[rq] option argument is
specified, however if explicit \[lq]man\[rq] is requested, the tool will
provide errors from man on stderr.
If the \[lq]no\-man\[rq] option if specified, or the manpager fails, the
short options will be output to stdout.
.RS 2
.PP
To successfully use the manpages feature requires the manpages to be
installed or on \f[I]MANPATH\f[R], See man(1) for more details.
.RE
.IP \[bu] 2
\f[B]\-v\f[R], \f[B]\-\-version\f[R]: Display version information for
this tool, supported tctis and exit.
.IP \[bu] 2
\f[B]\-V\f[R], \f[B]\-\-verbose\f[R]: Increase the information that the
tool prints to the console during its execution.
When using this option the file and line number are printed.
.IP \[bu] 2
\f[B]\-Q\f[R], \f[B]\-\-quiet\f[R]: Silence normal tool output to
stdout.
.IP \[bu] 2
\f[B]\-Z\f[R], \f[B]\-\-enable\-errata\f[R]: 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.
information many users may expect.
.SH TCTI Configuration
.PP
The TCTI or \[lq]Transmission Interface\[rq] is the communication
mechanism with the TPM.
TCTIs can be changed for communication with TPMs across different
mediums.
.PP
To control the TCTI, the tools respect:
.IP "1." 3
The command line option \f[B]\-T\f[R] or \f[B]\-\-tcti\f[R]
.IP "2." 3
The environment variable: \f[I]TPM2TOOLS_TCTI\f[R].
.PP
\f[B]Note:\f[R] The command line option always overrides the environment
variable.
.PP
The current known TCTIs are:
.IP \[bu] 2
tabrmd \- The resource manager, called
tabrmd (https://github.com/tpm2-software/tpm2-abrmd).
Note that tabrmd and abrmd as a tcti name are synonymous.
.IP \[bu] 2
mssim \- Typically used for communicating to the TPM software simulator.
.IP \[bu] 2
device \- Used when talking directly to a TPM device file.
.IP \[bu] 2
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 \f[I]ANY\f[R] options and \f[I]MUST BE\f[R] presented
as the exact text of \[lq]none\[rq].
.PP
The arguments to either the command line option or the environment
variable are in the form:
.PP
\f[C]<tcti\-name>:<tcti\-option\-config>\f[R]
.PP
Specifying an empty string for either the \f[C]<tcti\-name>\f[R] or
\f[C]<tcti\-option\-config>\f[R] results in the default being used for
that portion respectively.
.SS TCTI Defaults
.PP
When a TCTI is not specified, the default TCTI is searched for using
\f[I]dlopen(3)\f[R] semantics.
The tools will search for \f[I]tabrmd\f[R], \f[I]device\f[R] and
\f[I]mssim\f[R] TCTIs \f[B]IN THAT ORDER\f[R] and \f[B]USE THE FIRST ONE
FOUND\f[R].
You can query what TCTI will be chosen as the default by using the
\f[B]\-v\f[R] option to print the version information.
The \[lq]default\-tcti\[rq] key\-value pair will indicate which of the
aforementioned TCTIs is the default.
.SS Custom TCTIs
.PP
Any TCTI that implements the dynamic TCTI interface can be loaded.
The tools internally use \f[I]dlopen(3)\f[R], and the raw
\f[I]tcti\-name\f[R] value is used for the lookup.
Thus, this could be a path to the shared library, or a library name as
understood by \f[I]dlopen(3)\f[R] semantics.
.SH TCTI OPTIONS
.PP
This collection of options are used to configure the various known TCTI
modules available:
.IP \[bu] 2
\f[B]device\f[R]: For the device TCTI, the TPM character device file for
use by the device TCTI can be specified.
The default is \f[I]/dev/tpm0\f[R].
.RS 2
.PP
Example: \f[B]\-T device:/dev/tpm0\f[R] or \f[B]export
\f[BI]TPM2TOOLS_TCTI\f[B]=\[lq]device:/dev/tpm0\[rq]\f[R]
.RE
.IP \[bu] 2
\f[B]mssim\f[R]: 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.
.RS 2
.PP
Example: \f[B]\-T mssim:host=localhost,port=2321\f[R] or \f[B]export
\f[BI]TPM2TOOLS_TCTI\f[B]=\[lq]mssim:host=localhost,port=2321\[rq]\f[R]
.RE
.IP \[bu] 2
\f[B]abrmd\f[R]: 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.
.RS 2
.IP \[bu] 2
TCTI abrmd supports two keys:
.RS 2
.IP "1." 3
`bus_name' : The name of the tabrmd service on the bus (a string).
.IP "2." 3
`bus_type' : The type of the dbus instance (a string) limited to
`session' and `system'.
.RE
.PP
Specify the tabrmd tcti name and a config string of
\f[C]bus_name=com.example.FooBar\f[R]:
.IP
.nf
\f[C]
\[rs]\-\-tcti=tabrmd:bus_name=com.example.FooBar
\f[R]
.fi
.PP
Specify the default (abrmd) tcti and a config string of
\f[C]bus_type=session\f[R]:
.IP
.nf
\f[C]
\[rs]\-\-tcti:bus_type=session
\f[R]
.fi
.PP
\f[B]NOTE\f[R]: abrmd and tabrmd are synonymous.
the various known TCTI modules.
.RE
.SH Signature Format Specifiers
.PP
Format selection for the signature output file.
\f[B]tss\f[R] (the default) will output a binary blob according to the
TPM 2.0 specification and any potential compiler padding.
The option \f[B]plain\f[R] will output the plain signature data as
defined by the used cryptographic algorithm.
.SH EXAMPLES
.SS Sign and verify with the TPM using the \f[I]endorsement\f[R] hierarchy
.IP
.nf
\f[C]
tpm2_createprimary \-C e \-c primary.ctx

tpm2_create \-G rsa \-u rsa.pub \-r rsa.priv \-C primary.ctx

tpm2_load \-C primary.ctx \-u rsa.pub \-r rsa.priv \-c rsa.ctx

echo \[dq]my message\[dq] > message.dat

tpm2_sign \-c rsa.ctx \-g sha256 \-o sig.rssa message.dat

tpm2_verifysignature \-c rsa.ctx \-g sha256 \-s sig.rssa \-m message.dat
\f[R]
.fi
.SS Sign with the TPM and verify with OSSL
.IP
.nf
\f[C]
openssl ecparam \-name prime256v1 \-genkey \-noout \-out private.ecc.pem

openssl ec \-in private.ecc.pem \-out public.ecc.pem \-pubout

# Generate a hash to sign
echo \[dq]data to sign\[dq] > data.in.raw

sha256sum data.in.raw | awk \[aq]{ print \[dq]000000 \[dq] $1 }\[aq] | \[rs]
xxd \-r \-c 32 > data.in.digest

# Load the private key for signing
tpm2_loadexternal \-Q \-G ecc \-r private.ecc.pem \-c key.ctx

# Sign in the TPM and verify with OSSL
tpm2_sign \-Q \-c key.ctx \-g sha256 \-d \-f plain \-o data.out.signed data.in.digest

openssl dgst \-verify public.ecc.pem \-keyform pem \-sha256 \[rs]
\-signature data.out.signed data.in.raw
\f[R]
.fi
.SH Returns
.PP
Tools can return any of the following codes:
.IP \[bu] 2
0 \- Success.
.IP \[bu] 2
1 \- General non\-specific error.
.IP \[bu] 2
2 \- Options handling error.
.IP \[bu] 2
3 \- Authentication error.
.IP \[bu] 2
4 \- TCTI related error.
.IP \[bu] 2
5 \- Non supported scheme.
Applicable to tpm2_testparams.
.SH BUGS
.PP
Github Issues (https://github.com/tpm2-software/tpm2-tools/issues)
.SH HELP
.PP
See the Mailing List (https://lists.01.org/mailman/listinfo/tpm2)
