Provided by: tpm2-tools_5.4-1_amd64 bug

NAME

       tpm2_nvcertify(1) - Provides attestation of the contents of an NV index.

SYNOPSIS

       tpm2_nvcertify [OPTIONS] [ARGUMENTS]

DESCRIPTION

       tpm2_nvcertify(1) - Provides attestation of the contents of an NV index.  NOTE: As part of
       the attestation output, the NV index contents are revealed.

OPTIONS

       These options control the certification:

       • -C, --signingkey-context=OBJECT:

         The key object that signs the attestation structure.

       • -P, --signingkey-auth=AUTH:

         The authorization value provided for the object specified with -C.

       • -c, --nvauthobj-context=OBJECT:

         The object that is the authorization handle for the NV object.   It  is  either  the  NV
         index  handle  itself  or  the  platform/  owner  hierarchy handle.  If not specified it
         defaults to the NV index handle.

       • -p, --nvauthobj-auth=AUTH:

         The authorization value provided for the object specified with -c.

       • -g, --hash-algorithm=ALGORITHM:

         The hash algorithm to use in signature generation.

       • -s, --scheme=ALGORITHM:

         The signing scheme used to sign the attestation data.

       • -f, --format=FORMAT:

         Format selection for the signature output file.

       • -o, --signature=FILE:

         Output file name for the signature data.

       • -q, --qualification=FILE_OR_HEX_STR:

         Optional, the policy qualifier data that  the  signer  can  choose  to  include  in  the
         signature.  Can be either a hex string or path.

       • --size=NATURAL_NUMBER:

         Specifies  the  size  of  data  to  be  read  in bytes, starting from 0 if offset is not
         specified.  If not specified, the size of the data as reported by the public portion  of
         the index will be used.

       • --offset=NATURAL_NUMBER:

         The offset within the NV index to start reading from.

       • –attestation=FILE:

         The attestation data of the type TPM2_CREATION_INFO signed with signing key.

       • --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 unless rphash is also required.

       • --rphash=FILE

         File  path  to  record  the hash of the response parameters.  This is commonly termed as
         rpHash.

       • -S, --session=FILE:

         The session created using  tpm2_startauthsession.   This  can  be  used  to  specify  an
         auxiliary session for auditing and or encryption/decryption of the parameters.

       • -n, --name=FILE:

         The  name of the NV index that must be provided when only calculating the cpHash without
         actually dispatching the command to the TPM.

       • -signer-name=FILE:

         The name of the signing key that must be  provided  when  only  calculating  the  cpHash
         without actually dispatching the command to the TPM.

       • ARGUMENT the command line argument specifies the NV index or offset number.

   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”.

   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.

   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

       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.

Signature Format Specifiers

       Format selection for the signature output file.  tss (the default) will  output  a  binary
       blob  according  to  the  TPM  2.0  specification and any potential compiler padding.  The
       option plain will output the plain signature data as defined  by  the  used  cryptographic
       algorithm.  signature FORMAT.

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_nvdefine -s 32 -a "authread|authwrite" 1

              dd if=/dev/urandom bs=1 count=32 status=none| \

              tpm2_nvwrite 1 -i-
              tpm2_createprimary -C o -c primary.ctx -Q

              tpm2_create -G rsa -u rsa.pub -r rsa.priv -C primary.ctx -c signing_key.ctx -Q

              tpm2_readpublic -c signing_key.ctx -f pem -o sslpub.pem -Q

              tpm2_nvcertify -C signing_key.ctx -g sha256 -f plain -s rsassa \
              -o signature.bin --attestation attestation.bin --size 32 1

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.linuxfoundation.org/mailman/listinfo/tpm2)