Provided by: tpm2-tools_5.2-1build1_amd64 bug

NAME

       tpm2_geteccparameters(1) - Retrieves the parameters of an ECC curve identified by its TCG-
       assigned curveID.

SYNOPSIS

       tpm2_geteccparameters [OPTIONS]

DESCRIPTION

       tpm2_geteccparameters(1) - Retrieves the parameters of an ECC curve identified by its TCG-
       assigned curveID.

OPTIONS

ARGUMENT=ALGORITHM:

         Specify the ECC curve.  Example ecc521.

       • -o, --output=FILE

         Specify the file path to save the ECC parameters.

   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

   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

   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.

       • ecc - Elliptical Curve, defaults to ecc256.

       • ecc192 - 192 bit ECC

       • ecc224 - 224 bit ECC

       • ecc256 - 256 bit ECC

       • ecc384 - 384 bit ECC

       • ecc521 - 521 bit ECC

       • rsa - Default RSA: rsa2048

       • rsa1024 - RSA with 1024 bit keysize.

       • rsa2048 - RSA with 2048 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

   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 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.  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
         (https://github.com/tpm2-software/tpm2-abrmd).   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 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

              tpm2_geteccparameters ecc256 -o ecc.params

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 (https://github.com/tpm2-software/tpm2-tools/issues)

HELP

       See the Mailing List (https://lists.01.org/mailman/listinfo/tpm2)