1tpm2_getrandom(1)           General Commands Manual          tpm2_getrandom(1)
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4

NAME

6       tpm2_getrandom(1) - Retrieves random bytes from the TPM.
7

SYNOPSIS

9       tpm2_getrandom [OPTIONS] SIZE
10

DESCRIPTION

12       tpm2_getrandom(1) - Returns the next SIZE octets from the random number
13       generator.  The SIZE parameter is expected as the only argument to  the
14       tool.
15

OPTIONS

17       · -o,  –output=FILE  specifies the filename to output the raw bytes to.
18         Defaults to stdout as a hex string.
19

COMMON OPTIONS

21       This collection of options are common to many programs and provide  in‐
22       formation that many users may expect.
23
24       · -h,  –help: Display the tools manpage.  This requires the manpages to
25         be installed or on MANPATH, See man(1) for more details.
26
27       · -v, –version: Display version information for  this  tool,  supported
28         tctis and exit.
29
30       · -V,  –verbose:  Increase  the information that the tool prints to the
31         console during its execution.  When using this option  the  file  and
32         line number are printed.
33
34       · -Q, –quiet: Silence normal tool output to stdout.
35
36       · -Z,  –enable-errata: Enable the application of errata fixups.  Useful
37         if an errata fixup needs to be applied to commands sent to  the  TPM.
38         # TCTI ENVIRONMENT
39
40       This  collection of environment variables that may be used to configure
41       the various TCTI modules available.
42
43       The values passed through  these  variables  can  be  overridden  on  a
44       per-command basis using the available command line options, see the TC‐
45       TI_OPTIONS section.
46
47       The variables respected depend on how the software was configured.
48
49       · TPM2TOOLS_TCTI_NAME: Select the TCTI used for communication with  the
50         next  component down the TSS stack.  In most configurations this will
51         be the TPM but it could be a simulator or proxy.  The  current  known
52         TCTIs are:
53
54         · tabrmd    -    The    new    resource    manager,   called   tabrmd
55           (https://github.com/01org/tpm2-abrmd).
56
57         · socket - Typically used with the old resource manager,  or  talking
58           directly to a simulator.
59
60         · device - Used when talking directly to a TPM device file.
61
62       · TPM2TOOLS_DEVICE_FILE:  When  using  the device TCTI, specify the TPM
63         device file.  The default is “/dev/tpm0”.
64
65         Note: Using the tpm directly requires the users to ensure  that  con‐
66         current access does not occur and that they manage the tpm resources.
67         These tasks are usually managed by a resource  manager.   Linux  4.12
68         and  greater  supports an in kernel resource manager at “/dev/tpmrm”,
69         typically “/dev/tpmrm0”.
70
71       · TPM2TOOLS_SOCKET_ADDRESS: When using the socket TCTI, specify the do‐
72         main name or IP address used.  The default is 127.0.0.1.
73
74       · TPM2TOOLS_SOCKET_PORT:  When  using the socket TCTI, specify the port
75         number used.  The default is 2321.
76

TCTI OPTIONS

78       This collection of options are used to configure the varous  TCTI  mod‐
79       ules available.  They override any environment variables.
80
81       · -T, –tcti=TCTI_NAME[:TCTI_OPTIONS]: Select the TCTI used for communi‐
82         cation with the next component down the TSS stack.  In most  configu‐
83         rations    this    will    be    the    resource    manager:   tabrmd
84         (https://github.com/01org/tpm2-abrmd) Optionally, tcti  specific  op‐
85         tions can appended to TCTI_NAME by appending a : to TCTI_NAME.
86
87         · For the device TCTI, the TPM device file for use by the device TCTI
88           can be specified.  The  default  is  /dev/tpm0.   Example:  -T  de‐
89           vice:/dev/tpm0
90
91         · For  the socket TCTI, the domain name or IP address and port number
92           used by the socket can be specified.  The default are 127.0.0.1 and
93           2321.  Example: -T socket:127.0.0.1:2321
94
95         · For the abrmd TCTI, it takes no options.  Example: -T abrmd
96

EXAMPLES

98       Generate a random 20 bytes and output the binary data to a file:
99
100              tpm2_getrandom -o random.out 20
101
102       Generate a random 8 bytes and output the hex formated data to stdout:
103
104              tpm2_getrandom 8
105

RETURNS

107       0 on success or 1 on failure.
108

BUGS

110       Github Issues (https://github.com/01org/tpm2-tools/issues)
111

HELP

113       See the Mailing List (https://lists.01.org/mailman/listinfo/tpm2)
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117tpm2-tools                      SEPTEMBER 2017               tpm2_getrandom(1)