Provided by: tpm2-tools_3.1.3-2_amd64 bug


       tpm2_verifysignature(1) - Validates a signature using the TPM.


       tpm2_verifysignature [OPTIONS]


       tpm2_verifysignature(1)  uses  loaded  keys  to validate a signature on a message with the
       message digest passed to the TPM.  If the signature check  succeeds,  then  the  TPM  will
       produce  a  TPMT_TK_VERIFIED.   Otherwise,  the  TPM  shall  return  TPM_RC_SIGNATURE.  If
       KEY_HANDLE references an asymmetric key, only the public portion of the key  needs  to  be
       loaded.   If  KEY_HANDLE  references a symmetric key, both the public and private portions
       need to be loaded.


       · -k, –key-handle=KEY_HANDLE:

         Handle of key that will used in the validation.

       · -c, –key-context=KEY_CONTEXT_FILE:

         Filename of the key context used for the operation.

       · -g, –halg=HASH_ALGORITHM:

         The hash algorithm used to digest the message.  Algorithms should follow the “formatting
         standards,   see   section”Algorithm   Specifiers“.  Also,  see  section”Supported  Hash
         Algorithms" for a list of supported hash algorithms.

       · -m, –msg=MSG_FILE:

         The message file, containing the content to be digested.

       · -D, –digest=DIGEST_FILE:

         The input hash file, containing the hash of the message.  If this  option  is  selected,
         then the message (-m) and algorithm (-g) options do not need to be specified.

       · -s, –sig=SIG_FILE:

         The input signature file of the signature to be validated.

       · -r, –raw:

         Set the input signature file to raw type.  The default is TPMT_SIGNATURE.

       · -t, –ticket=TICKET_FILE:

         The ticket file to record the validation structure.

       · -S, –input-session-handle=SESSION_HANDLE:

         Optional Input session handle from a policy session for authorization.


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

       · -h, –help: Display the tools manpage.  This 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.  # TCTI ENVIRONMENT

       This  collection  of  environment variables that may be used to configure the various TCTI
       modules available.

       The values passed through these variables can be overridden on a per-command  basis  using
       the available command line options, see the TCTI_OPTIONS section.

       The variables respected depend on how the software was configured.

       · TPM2TOOLS_TCTI_NAME: Select the TCTI used for communication with the next component down
         the TSS stack.  In most configurations this will be the TPM but it could be a  simulator
         or proxy.  The current known TCTIs are:

         · tabrmd       -       The       new      resource      manager,      called      tabrmd

         · socket - Typically used with the old  resource  manager,  or  talking  directly  to  a

         · device - Used when talking directly to a TPM device file.

       · TPM2TOOLS_DEVICE_FILE:  When  using  the  device TCTI, specify the TPM device file.  The
         default is “/dev/tpm0”.

         Note: Using the tpm directly requires the users to ensure that  concurrent  access  does
         not  occur and that they manage the tpm resources.  These tasks are usually managed by a
         resource manager.  Linux 4.12 and greater supports an  in  kernel  resource  manager  at
         “/dev/tpmrm”, typically “/dev/tpmrm0”.

       · TPM2TOOLS_SOCKET_ADDRESS:  When  using  the  socket  TCTI, specify the domain name or IP
         address used.  The default is

       · TPM2TOOLS_SOCKET_PORT: When using the socket TCTI, specify the port  number  used.   The
         default is 2321.


       This  collection of options are used to configure the varous TCTI modules available.  They
       override any environment variables.

       · -T, –tcti=TCTI_NAME[:TCTI_OPTIONS]: Select the TCTI used for communication with the next
         component down the TSS stack.  In most configurations this will be the resource manager:
         tabrmd  (  Optionally,  tcti  specific  options  can
         appended to TCTI_NAME by appending a : to TCTI_NAME.

         · For  the device TCTI, the TPM device file for use by the device TCTI can be specified.
           The default is /dev/tpm0.  Example: -T device:/dev/tpm0

         · For the socket TCTI, the domain name or IP address and port number used by the  socket
           can   be   specified.    The   default   are   and   2321.    Example:  -T

         · For the abrmd TCTI, it takes no options.  Example: -T abrmd

Password Formatting

       Passwords are interpreted in two forms, string and hex-string.  A string password  is  not
       interpreted,  and  is  directly used for authorization.  A hex-string, is converted from a
       hexidecimal form into a byte array form, thus allowing passwords with non-printable and/or
       terminal un-friendly characters.

       By  default  passwords  are  assumed to be in the string form.  Password form is specified
       with special prefix values, they are:

       · str: - Used to indicate it is a raw string.  Useful for escaping a password that  starts
         with the “hex:” prefix.

       · hex: - Used when specifying a password in hex string format.

Supported Hash Algorithms

       Supported hash algorithms are:

       · 0x4 or sha1 for TPM_ALG_SHA1 (default)

       · 0xB or sha256 for TPM_ALG_SHA256

       · 0xC or sha384 for TPM_ALG_SHA384

       · 0xD or sha512 for TPM_ALG_SHA512

       · 0x12 or sm3_256 for TPM_ALG_SM3_256

       NOTE: Your TPM may not support all algorithms.

Algorithm Specfiers

       Options  that  take algorithms support “nice-names”.  Nice names, like sha1 can be used in
       place of the raw hex for sha1: 0x4.  The nice names are converted by stripping the leading
       TPM_ALG_  from  the  Algorithm  Name  field and converting it to lower case.  For instance
       TPM_ALG_SHA3_256 becomes sha3_256.

       The    algorithms    can    be    found     at:     <


              tpm2_verifysignature -k 0x81010001 -g sha256 -m <filePath> -s <filePath> -t <filePath>
              tpm2_verifysignature -k 0x81010001 -D <filePath> -s <filePath> -t <filePath>
              tpm2_verifysignature -c key.context -g sha256 -m <filePath> -s <filePath> -t <filePath>


       0 on success or 1 on failure.


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