1tpm2_flushcontext(1) General Commands Manual tpm2_flushcontext(1)
2
6 tpm2_flushcontext(1) - Remove a specified handle, or all contexts asso‐
7 ciated with a transient object, loaded session or saved session from
8 the TPM.
9
11 tpm2_flushcontext [OPTIONS] [ARGUMENT]
12
14 tpm2_flushcontext(1) - Remove a specified handle, or all contexts asso‐
15 ciated with a transient object, loaded session or saved session from
16 the TPM. The object to be flushed is specified as the first argument
17 to the tool and is in one of the following forms: - The handle of the
18 object to be flushed from the TPM. Must be a valid handle number. -
19 Flush a session via a session file. A session file is generated from
20 tpm2_startauthsession(1)’s -S option.
21
23 • -t, --transient-object:
24 Remove all transient objects.
26 • -l, --loaded-session:
28 Remove all loaded sessions.
30 • -s, --saved-session:
32 Remove all saved sessions.
34 • ARGUMENT the command line argument specifies the OBJECT to be removed
36 from the TPM resident memory.
37
39 This collection of options are common to many programs and provide in‐
40 formation that many users may expect.
41 • -h, --help=[man|no-man]: Display the tools manpage. By default, it
43 attempts to invoke the manpager for the tool, however, on failure
44 will output a short tool summary. This is the same behavior if the
45 “man” option argument is specified, however if explicit “man” is re‐
46 quested, the tool will provide errors from man on stderr. If the
47 “no-man” option if specified, or the manpager fails, the short op‐
48 tions will be output to stdout.
49 To successfully use the manpages feature requires the manpages to be
51 installed or on MANPATH, See man(1) for more details.
52 • -v, --version: Display version information for this tool, supported
54 tctis and exit.
55 • -V, --verbose: Increase the information that the tool prints to the
57 console during its execution. When using this option the file and
58 line number are printed.
59 • -Q, --quiet: Silence normal tool output to stdout.
61 • -Z, --enable-errata: Enable the application of errata fixups. Useful
63 if an errata fixup needs to be applied to commands sent to the TPM.
64 Defining the environment TPM2TOOLS_ENABLE_ERRATA is equivalent.
65
67 The TCTI or “Transmission Interface” is the communication mechanism
68 with the TPM. TCTIs can be changed for communication with TPMs across
69 different mediums.
70 To control the TCTI, the tools respect:
72 1. The command line option -T or --tcti
74 2. The environment variable: TPM2TOOLS_TCTI.
76 Note: The command line option always overrides the environment vari‐
78 able.
79 The current known TCTIs are:
81 • tabrmd - The resource manager, called tabrmd
83 (https://github.com/tpm2-software/tpm2-abrmd). Note that tabrmd and
84 abrmd as a tcti name are synonymous.
85 • mssim - Typically used for communicating to the TPM software simula‐
87 tor.
88 • device - Used when talking directly to a TPM device file.
90 • none - Do not initalize a connection with the TPM. Some tools allow
92 for off-tpm options and thus support not using a TCTI. Tools that do
93 not support it will error when attempted to be used without a TCTI
94 connection. Does not support ANY options and MUST BE presented as
95 the exact text of “none”.
96 The arguments to either the command line option or the environment
98 variable are in the form:
99 <tcti-name>:<tcti-option-config>
101 Specifying an empty string for either the <tcti-name> or <tcti-op‐
103 tion-config> results in the default being used for that portion respec‐
104 tively.
105 TCTI Defaults
107 When a TCTI is not specified, the default TCTI is searched for using
108 dlopen(3) semantics. The tools will search for tabrmd, device and
109 mssim TCTIs IN THAT ORDER and USE THE FIRST ONE FOUND. You can query
110 what TCTI will be chosen as the default by using the -v option to print
111 the version information. The “default-tcti” key-value pair will indi‐
112 cate which of the aforementioned TCTIs is the default.
113 Custom TCTIs
115 Any TCTI that implements the dynamic TCTI interface can be loaded. The
116 tools internally use dlopen(3), and the raw tcti-name value is used for
117 the lookup. Thus, this could be a path to the shared library, or a li‐
118 brary name as understood by dlopen(3) semantics.
119
121 This collection of options are used to configure the various known TCTI
122 modules available:
123 • device: For the device TCTI, the TPM character device file for use by
125 the device TCTI can be specified. The default is /dev/tpm0.
126 Example: -T device:/dev/tpm0 or export TPM2TOOLS_TCTI=“de‐
128 vice:/dev/tpm0”
129 • mssim: For the mssim TCTI, the domain name or IP address and port
131 number used by the simulator can be specified. The default are
132 127.0.0.1 and 2321.
133 Example: -T mssim:host=localhost,port=2321 or export TPM2TOOLS_TC‐
135 TI=“mssim:host=localhost,port=2321”
136 • abrmd: For the abrmd TCTI, the configuration string format is a se‐
138 ries of simple key value pairs separated by a `,' character. Each
139 key and value string are separated by a `=' character.
140 • TCTI abrmd supports two keys:
142 1. `bus_name' : The name of the tabrmd service on the bus (a
144 string).
145 2. `bus_type' : The type of the dbus instance (a string) limited to
147 `session' and `system'.
148 Specify the tabrmd tcti name and a config string of bus_name=com.ex‐
150 ample.FooBar:
151 \--tcti=tabrmd:bus_name=com.example.FooBar
153 Specify the default (abrmd) tcti and a config string of bus_type=ses‐
155 sion:
156 \--tcti:bus_type=session
158 NOTE: abrmd and tabrmd are synonymous.
160
162 Flushing a Transient Object
163 Typically, when using the TPM, the interactions occur through a re‐
164 source manager, like tpm2-abrmd(8). When the process exits, transient
165 object handles are flushed. Thus, flushing transient objects through
166 the command line is not required. However, when interacting with the
167 TPM directly, this scenario is possible. The below example assumes di‐
168 rect TPM access not brokered by a resource manager. Specifically we
169 will use the simulator.
170 tpm2_createprimary -Tmssim -c primary.ctx
172 tpm2_getcap -T mssim handles-transient
174 - 0x80000000
175 tpm2_flushcontext -T mssim 0x80000000
177 Flush All the Transient Objects
179 tpm2_flushcontext \--transient-object
180 Flush a Session
182 tpm2_startauthsession -S session.dat
183 tpm2_flushcontext session.dat
185
187 Tools can return any of the following codes:
188 • 0 - Success.
190 • 1 - General non-specific error.
192 • 2 - Options handling error.
194 • 3 - Authentication error.
196 • 4 - TCTI related error.
198 • 5 - Non supported scheme. Applicable to tpm2_testparams.
200
202 Github Issues (https://github.com/tpm2-software/tpm2-tools/issues)
203
205 See the Mailing List (https://lists.01.org/mailman/listinfo/tpm2)
206tpm2-tools tpm2_flushcontext(1)