1tpm2_policyauthorizenv(1) General Commands Manual tpm2_policyauthorizenv(1)
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6 tpm2_policyauthorizenv(1) - Allows for mutable policies by referencing
7 to a policy from an NV index.
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10 tpm2_policyauthorizenv [OPTIONS] [ARGUMENT]
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13 tpm2_policyauthorizenv(1) - This command allows for policies to change
14 by referencing the authorization policy written to an NV index. The NV
15 index containing the authorization policy should remain readable even
16 for trial session. The index can be specified as raw handle or an off‐
17 set value to the nv handle range "TPM2_HR_NV_INDEX".
18
20 · -C, --hierarchy=OBJECT:
21 Specifies the hierarchy used to authorize. Supported options are:
22 · o for TPM_RH_OWNER
24 · p for TPM_RH_PLATFORM
26 · <num> where a hierarchy handle or nv-index may be used.
28 When -C isn't explicitly passed the index handle will be used to au‐
30 thorize against the index. The index auth value is set via the -p
31 option to tpm2_nvdefine(1).
32 · -P, --auth=AUTH:
34 Specifies the authorization value for the hierarchy.
36 · -L, --policy=FILE:
38 File to save the policy digest.
40 · -S, --session=FILE:
42 The policy session file generated via the -S option to tpm2_star‐
44 tauthsession(1).
45 References
48 This collection of options are common to many programs and provide in‐
49 formation that many users may expect.
50 · -h, --help=[man|no-man]: Display the tools manpage. By default, it
52 attempts to invoke the manpager for the tool, however, on failure
53 will output a short tool summary. This is the same behavior if the
54 "man" option argument is specified, however if explicit "man" is re‐
55 quested, the tool will provide errors from man on stderr. If the
56 "no-man" option if specified, or the manpager fails, the short op‐
57 tions will be output to stdout.
58 To successfully use the manpages feature requires the manpages to be
60 installed or on MANPATH, See man(1) for more details.
61 · -v, --version: Display version information for this tool, supported
63 tctis and exit.
64 · -V, --verbose: Increase the information that the tool prints to the
66 console during its execution. When using this option the file and
67 line number are printed.
68 · -Q, --quiet: Silence normal tool output to stdout.
70 · -Z, --enable-errata: Enable the application of errata fixups. Useful
72 if an errata fixup needs to be applied to commands sent to the TPM.
73 Defining the environment TPM2TOOLS_ENABLE_ERRATA is equivalent. in‐
74 formation many users may expect.
75
77 The TCTI or "Transmission Interface" is the communication mechanism
78 with the TPM. TCTIs can be changed for communication with TPMs across
79 different mediums.
80 To control the TCTI, the tools respect:
82 1. The command line option -T or --tcti
84 2. The environment variable: TPM2TOOLS_TCTI.
86 Note: The command line option always overrides the environment vari‐
88 able.
89 The current known TCTIs are:
91 · tabrmd - The resource manager, called tabrmd
93 (https://github.com/tpm2-software/tpm2-abrmd). Note that tabrmd and
94 abrmd as a tcti name are synonymous.
95 · mssim - Typically used for communicating to the TPM software simula‐
97 tor.
98 · device - Used when talking directly to a TPM device file.
100 · none - Do not initalize a connection with the TPM. Some tools allow
102 for off-tpm options and thus support not using a TCTI. Tools that do
103 not support it will error when attempted to be used without a TCTI
104 connection. Does not support ANY options and MUST BE presented as
105 the exact text of "none".
106 The arguments to either the command line option or the environment
108 variable are in the form:
109 <tcti-name>:<tcti-option-config>
111 Specifying an empty string for either the <tcti-name> or <tcti-op‐
113 tion-config> results in the default being used for that portion respec‐
114 tively.
115 TCTI Defaults
117 When a TCTI is not specified, the default TCTI is searched for using
118 dlopen(3) semantics. The tools will search for tabrmd, device and
119 mssim TCTIs IN THAT ORDER and USE THE FIRST ONE FOUND. You can query
120 what TCTI will be chosen as the default by using the -v option to print
121 the version information. The "default-tcti" key-value pair will indi‐
122 cate which of the aforementioned TCTIs is the default.
123 Custom TCTIs
125 Any TCTI that implements the dynamic TCTI interface can be loaded. The
126 tools internally use dlopen(3), and the raw tcti-name value is used for
127 the lookup. Thus, this could be a path to the shared library, or a li‐
128 brary name as understood by dlopen(3) semantics.
129
131 This collection of options are used to configure the various known TCTI
132 modules available:
133 · device: For the device TCTI, the TPM character device file for use by
135 the device TCTI can be specified. The default is /dev/tpm0.
136 Example: -T device:/dev/tpm0 or export TPM2TOOLS_TCTI="de‐
138 vice:/dev/tpm0"
139 · mssim: For the mssim TCTI, the domain name or IP address and port
141 number used by the simulator can be specified. The default are
142 127.0.0.1 and 2321.
143 Example: -T mssim:host=localhost,port=2321 or export TPM2TOOLS_TC‐
145 TI="mssim:host=localhost,port=2321"
146 · abrmd: For the abrmd TCTI, the configuration string format is a se‐
148 ries of simple key value pairs separated by a ',' character. Each
149 key and value string are separated by a '=' character.
150 · TCTI abrmd supports two keys:
152 1. 'bus_name' : The name of the tabrmd service on the bus (a
154 string).
155 2. 'bus_type' : The type of the dbus instance (a string) limited to
157 'session' and 'system'.
158 Specify the tabrmd tcti name and a config string of bus_name=com.ex‐
160 ample.FooBar:
161 \--tcti=tabrmd:bus_name=com.example.FooBar
163 Specify the default (abrmd) tcti and a config string of bus_type=ses‐
165 sion:
166 \--tcti:bus_type=session
168 NOTE: abrmd and tabrmd are synonymous. the various known TCTI mod‐
170 ules.
171
173 Create a policypassword and write the policy digest to an NV Index.
174 Build a policyauthorizenv policy referencing the NV index in a trial
175 session. The resultant policy digest is then used in creation of ob‐
176 jects.
177 In a policy authorization session, first satisfy the policy written to
179 the NV index. Then run the policyauthorizenv which satisfies the au‐
180 thorization for the object.
181 Define the test NV Index to store the auth policy
183 nv_test_index=0x01500001
184 tpm2_nvdefine -C o -p nvpass $nv_test_index -a "authread|authwrite" -s 34
185 Define the auth policy
187 tpm2_startauthsession -S session.ctx
188 tpm2_policypassword -S session.ctx -L policy.pass
189 tpm2_flushcontext session.ctx
190 Write the auth policy to the NV Index
192 echo "000b" | xxd -p -r | cat - policy.pass | \
193 tpm2_nvwrite -C $nv_test_index -P nvpass $nv_test_index -i-
194 Define the policyauthorizenv
196 tpm2_startauthsession -S session.ctx
197 tpm2_policyauthorizenv -S session.ctx -C $nv_test_index -P nvpass \
198 -L policyauthorizenv.1500001 $nv_test_index
199 tpm2_flushcontext session.ctx
200 Create and load a sealing object with auth policy =
202 policyauthorizenv
203 tpm2_createprimary -C o -c prim.ctx
205 echo "secretdata" | \
207 tpm2_create -C prim.ctx -u key.pub -r key.priv \
208 -a "fixedtpm|fixedparent|adminwithpolicy" -L policyauthorizenv.1500001 -i-
209 tpm2_load -C prim.ctx -u key.pub -r key.priv -c key.ctx
211 Satisfy the auth policy stored in the NV Index and thus
213 policyauthorizenv
214 tpm2_startauthsession -S session.ctx --policy-session
216 tpm2_policypassword -S session.ctx
217 tpm2_policyauthorizenv -S session.ctx -C $nv_test_index -P nvpass $nv_test_index
218 tpm2_unseal -c key.ctx -p session:session.ctx
219 tpm2_flushcontext session.ctx
220
222 Tools can return any of the following codes:
223 · 0 - Success.
225 · 1 - General non-specific error.
227 · 2 - Options handling error.
229 · 3 - Authentication error.
231 · 4 - TCTI related error.
233 · 5 - Non supported scheme. Applicable to tpm2_testparams.
235
237 It expects a session to be already established via tpm2_startauthses‐
238 sion(1) and requires one of the following:
239 · direct device access
241 · extended session support with tpm2-abrmd.
243 Without it, most resource managers will not save session state between
245 command invocations.
246
248 Github Issues (https://github.com/tpm2-software/tpm2-tools/issues)
249
251 See the Mailing List (https://lists.01.org/mailman/listinfo/tpm2)
252tpm2-tools tpm2_policyauthorizenv(1)