1tpm2_nvreadlock(1) General Commands Manual tpm2_nvreadlock(1)
2
6 tpm2_nvreadlock(1) - Lock the Non-Volatile (NV) index for further
7 reads.
8
10 tpm2_nvreadlock [OPTIONS] [ARGUMENT]
11
13 tpm2_nvreadlock(1) - Lock the Non-Volatile (NV) index for further
14 reads. The lock on the NN index is unlocked when the TPM is restarted
15 and the NV index becomes readable again. The index can be specified as
16 raw handle or an offset value to the nv handle range "TPM2_HR_NV_IN‐
17 DEX".
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 · ARGUMENT the command line argument specifies the NV index or offset
38 number.
39 References
42 The type of a context object, whether it is a handle or file name, is
43 determined according to the following logic in-order:
44 · If the argument is a file path, then the file is loaded as a restored
46 TPM transient object.
47 · If the argument is a prefix match on one of:
49 · owner: the owner hierarchy
51 · platform: the platform hierarchy
53 · endorsement: the endorsement hierarchy
55 · lockout: the lockout control persistent object
57 · If the argument argument can be loaded as a number it will be treat
59 as a handle, e.g. 0x81010013 and used directly.OBJECT.
60
62 Authorization for use of an object in TPM2.0 can come in 3 different
63 forms: 1. Password 2. HMAC 3. Sessions
64 NOTE: "Authorizations default to the EMPTY PASSWORD when not speci‐
66 fied".
67 Passwords
69 Passwords are interpreted in the following forms below using prefix
70 identifiers.
71 Note: By default passwords are assumed to be in the string form when
73 they do not have a prefix.
74 String
76 A string password, specified by prefix "str:" or it's absence (raw
77 string without prefix) is not interpreted, and is directly used for au‐
78 thorization.
79 Examples
81 foobar
82 str:foobar
83 Hex-string
85 A hex-string password, specified by prefix "hex:" is converted from a
86 hexidecimal form into a byte array form, thus allowing passwords with
87 non-printable and/or terminal un-friendly characters.
88 Example
90 hex:0x1122334455667788
91 File
93 A file based password, specified be prefix "file:" should be the path
94 of a file containing the password to be read by the tool or a "-" to
95 use stdin. Storing passwords in files prevents information leakage,
96 passwords passed as options can be read from the process list or common
97 shell history features.
98 Examples
100 # to use stdin and be prompted
101 file:-
102 # to use a file from a path
104 file:path/to/password/file
105 # to echo a password via stdin:
107 echo foobar | tpm2_tool -p file:-
108 # to use a bash here-string via stdin:
110 tpm2_tool -p file:- <<< foobar
112 Sessions
114 When using a policy session to authorize the use of an object, prefix
115 the option argument with the session keyword. Then indicate a path to
116 a session file that was created with tpm2_startauthsession(1). Option‐
117 ally, if the session requires an auth value to be sent with the session
118 handle (eg policy password), then append a + and a string as described
119 in the Passwords section.
120 Examples
122 To use a session context file called session.ctx.
123 session:session.ctx
125 To use a session context file called session.ctx AND send the authvalue
127 mypassword.
128 session:session.ctx+mypassword
130 To use a session context file called session.ctx AND send the HEX auth‐
132 value 0x11223344.
133 session:session.ctx+hex:11223344
135 PCR Authorizations
137 You can satisfy a PCR policy using the "pcr:" prefix and the PCR mini‐
138 language. The PCR minilanguage is as follows:
139 <pcr-spec>=<raw-pcr-file>
140 The PCR spec is documented in in the section "PCR bank specifiers".
142 The raw-pcr-file is an optional the output of the raw PCR contents as
144 returned by tpm2_pcrread(1).
145 PCR bank specifiers (common/pcr.md)
147 Examples
149 To satisfy a PCR policy of sha256 on banks 0, 1, 2 and 3 use a specifi‐
150 er of:
151 pcr:sha256:0,1,2,3
153 specifying AUTH.
155
157 This collection of options are common to many programs and provide in‐
158 formation that many users may expect.
159 · -h, --help=[man|no-man]: Display the tools manpage. By default, it
161 attempts to invoke the manpager for the tool, however, on failure
162 will output a short tool summary. This is the same behavior if the
163 "man" option argument is specified, however if explicit "man" is re‐
164 quested, the tool will provide errors from man on stderr. If the
165 "no-man" option if specified, or the manpager fails, the short op‐
166 tions will be output to stdout.
167 To successfully use the manpages feature requires the manpages to be
169 installed or on MANPATH, See man(1) for more details.
170 · -v, --version: Display version information for this tool, supported
172 tctis and exit.
173 · -V, --verbose: Increase the information that the tool prints to the
175 console during its execution. When using this option the file and
176 line number are printed.
177 · -Q, --quiet: Silence normal tool output to stdout.
179 · -Z, --enable-errata: Enable the application of errata fixups. Useful
181 if an errata fixup needs to be applied to commands sent to the TPM.
182 Defining the environment TPM2TOOLS_ENABLE_ERRATA is equivalent. in‐
183 formation many users may expect.
184
186 The TCTI or "Transmission Interface" is the communication mechanism
187 with the TPM. TCTIs can be changed for communication with TPMs across
188 different mediums.
189 To control the TCTI, the tools respect:
191 1. The command line option -T or --tcti
193 2. The environment variable: TPM2TOOLS_TCTI.
195 Note: The command line option always overrides the environment vari‐
197 able.
198 The current known TCTIs are:
200 · tabrmd - The resource manager, called tabrmd
202 (https://github.com/tpm2-software/tpm2-abrmd). Note that tabrmd and
203 abrmd as a tcti name are synonymous.
204 · mssim - Typically used for communicating to the TPM software simula‐
206 tor.
207 · device - Used when talking directly to a TPM device file.
209 · none - Do not initalize a connection with the TPM. Some tools allow
211 for off-tpm options and thus support not using a TCTI. Tools that do
212 not support it will error when attempted to be used without a TCTI
213 connection. Does not support ANY options and MUST BE presented as
214 the exact text of "none".
215 The arguments to either the command line option or the environment
217 variable are in the form:
218 <tcti-name>:<tcti-option-config>
220 Specifying an empty string for either the <tcti-name> or <tcti-op‐
222 tion-config> results in the default being used for that portion respec‐
223 tively.
224 TCTI Defaults
226 When a TCTI is not specified, the default TCTI is searched for using
227 dlopen(3) semantics. The tools will search for tabrmd, device and
228 mssim TCTIs IN THAT ORDER and USE THE FIRST ONE FOUND. You can query
229 what TCTI will be chosen as the default by using the -v option to print
230 the version information. The "default-tcti" key-value pair will indi‐
231 cate which of the aforementioned TCTIs is the default.
232 Custom TCTIs
234 Any TCTI that implements the dynamic TCTI interface can be loaded. The
235 tools internally use dlopen(3), and the raw tcti-name value is used for
236 the lookup. Thus, this could be a path to the shared library, or a li‐
237 brary name as understood by dlopen(3) semantics.
238
240 This collection of options are used to configure the various known TCTI
241 modules available:
242 · device: For the device TCTI, the TPM character device file for use by
244 the device TCTI can be specified. The default is /dev/tpm0.
245 Example: -T device:/dev/tpm0 or export TPM2TOOLS_TCTI="de‐
247 vice:/dev/tpm0"
248 · mssim: For the mssim TCTI, the domain name or IP address and port
250 number used by the simulator can be specified. The default are
251 127.0.0.1 and 2321.
252 Example: -T mssim:host=localhost,port=2321 or export TPM2TOOLS_TC‐
254 TI="mssim:host=localhost,port=2321"
255 · abrmd: For the abrmd TCTI, the configuration string format is a se‐
257 ries of simple key value pairs separated by a ',' character. Each
258 key and value string are separated by a '=' character.
259 · TCTI abrmd supports two keys:
261 1. 'bus_name' : The name of the tabrmd service on the bus (a
263 string).
264 2. 'bus_type' : The type of the dbus instance (a string) limited to
266 'session' and 'system'.
267 Specify the tabrmd tcti name and a config string of bus_name=com.ex‐
269 ample.FooBar:
270 \--tcti=tabrmd:bus_name=com.example.FooBar
272 Specify the default (abrmd) tcti and a config string of bus_type=ses‐
274 sion:
275 \--tcti:bus_type=session
277 NOTE: abrmd and tabrmd are synonymous. the various known TCTI mod‐
279 ules.
280
282 Lock an index
283 tpm2_nvdefine -Q 1 -C o -s 32 \
284 -a "ownerread|policywrite|ownerwrite|read_stclear"
285 echo "foobar" > nv.readlock
287 tpm2_nvwrite -Q 0x01000001 -C o -i nv.readlock
289 tpm2_nvread -Q 1 -C o -s 6 -o 0
291 tpm2_nvreadlock -Q 1 -C o
293
295 Tools can return any of the following codes:
296 · 0 - Success.
298 · 1 - General non-specific error.
300 · 2 - Options handling error.
302 · 3 - Authentication error.
304 · 4 - TCTI related error.
306 · 5 - Non supported scheme. Applicable to tpm2_testparams.
308
310 Github Issues (https://github.com/tpm2-software/tpm2-tools/issues)
311
313 See the Mailing List (https://lists.01.org/mailman/listinfo/tpm2)
314tpm2-tools tpm2_nvreadlock(1)