1tpm2_nvsetbits(1) General Commands Manual tpm2_nvsetbits(1)
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6 tpm2_nvsetbits(1) - Bitwise OR bits into a Non-Volatile (NV).
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9 tpm2_nvsetbits [OPTIONS] [ARGUMENT]
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12 tpm2_nvsetbits(1) - Bitwise OR bits into a Non-Volatile (NV). The NV
13 index must be of type “bits” which is specified via the “nt” field when
14 creating the NV space with tpm2_nvdefine(1). The index can be speci‐
15 fied as raw handle or an offset value to the NV handle range
16 “TPM2_HR_NV_INDEX”.
17
19 • -C, --hierarchy=OBJECT:
20 Specifies the hierarchy used to authorize. Supported options are:
21 • o for TPM_RH_OWNER
23 • p for TPM_RH_PLATFORM
25 • <num> where a hierarchy handle or nv-index may be used.
27 When -C isn’t explicitly passed the index handle will be used to au‐
29 thorize against the index. The index auth value is set via the -p
30 option to tpm2_nvdefine(1).
31 • -P, --auth=AUTH:
33 Specifies the authorization value for the hierarchy.
35 • -i, --bits=BITS:
37 Specifies the bit value as a number to bitwise OR into the current
39 value of the NV index.
40 • --cphash=FILE
42 File path to record the hash of the command parameters. This is com‐
44 monly termed as cpHash. NOTE: When this option is selected, The tool
45 will not actually execute the command, it simply returns a cpHash,
46 unless rphash is also required.
47 • --rphash=FILE
49 File path to record the hash of the response parameters. This is
51 commonly termed as rpHash.
52 • -S, --session=FILE:
54 The session created using tpm2_startauthsession. This can be used to
56 specify an auxiliary session for auditing and or encryption/decryp‐
57 tion of the parameters.
58 • -n, --name=FILE:
60 The name of the NV index that must be provided when only calculating
62 the cpHash without actually dispatching the command to the TPM.
63 • ARGUMENT the command line argument specifies the NV index or offset
65 number.
66 References
69 The type of a context object, whether it is a handle or file name, is
70 determined according to the following logic in-order:
71 • If the argument is a file path, then the file is loaded as a restored
73 TPM transient object.
74 • If the argument is a prefix match on one of:
76 • owner: the owner hierarchy
78 • platform: the platform hierarchy
80 • endorsement: the endorsement hierarchy
82 • lockout: the lockout control persistent object
84 • If the argument argument can be loaded as a number it will be treat
86 as a handle, e.g. 0x81010013 and used directly._OBJECT_.
87
89 Authorization for use of an object in TPM2.0 can come in 3 different
90 forms: 1. Password 2. HMAC 3. Sessions
91 NOTE: “Authorizations default to the EMPTY PASSWORD when not speci‐
93 fied”.
94 Passwords
96 Passwords are interpreted in the following forms below using prefix
97 identifiers.
98 Note: By default passwords are assumed to be in the string form when
100 they do not have a prefix.
101 String
103 A string password, specified by prefix “str:” or it’s absence (raw
104 string without prefix) is not interpreted, and is directly used for au‐
105 thorization.
106 Examples
108 foobar
109 str:foobar
110 Hex-string
112 A hex-string password, specified by prefix “hex:” is converted from a
113 hexidecimal form into a byte array form, thus allowing passwords with
114 non-printable and/or terminal un-friendly characters.
115 Example
117 hex:1122334455667788
118 File
120 A file based password, specified be prefix “file:” should be the path
121 of a file containing the password to be read by the tool or a “-” to
122 use stdin. Storing passwords in files prevents information leakage,
123 passwords passed as options can be read from the process list or common
124 shell history features.
125 Examples
127 # to use stdin and be prompted
128 file:-
129 # to use a file from a path
131 file:path/to/password/file
132 # to echo a password via stdin:
134 echo foobar | tpm2_tool -p file:-
135 # to use a bash here-string via stdin:
137 tpm2_tool -p file:- <<< foobar
139 Sessions
141 When using a policy session to authorize the use of an object, prefix
142 the option argument with the session keyword. Then indicate a path to
143 a session file that was created with tpm2_startauthsession(1). Option‐
144 ally, if the session requires an auth value to be sent with the session
145 handle (eg policy password), then append a + and a string as described
146 in the Passwords section.
147 Examples
149 To use a session context file called session.ctx.
150 session:session.ctx
152 To use a session context file called session.ctx AND send the authvalue
154 mypassword.
155 session:session.ctx+mypassword
157 To use a session context file called session.ctx AND send the HEX auth‐
159 value 0x11223344.
160 session:session.ctx+hex:11223344
162 PCR Authorizations
164 You can satisfy a PCR policy using the “pcr:” prefix and the PCR mini‐
165 language. The PCR minilanguage is as follows:
166 <pcr-spec>=<raw-pcr-file>
167 The PCR spec is documented in in the section “PCR bank specifiers”.
169 The raw-pcr-file is an optional argument that contains the output of
171 the raw PCR contents as returned by tpm2_pcrread(1).
172 PCR bank specifiers (pcr.md)
174 Examples
176 To satisfy a PCR policy of sha256 on banks 0, 1, 2 and 3 use a specifi‐
177 er of:
178 pcr:sha256:0,1,2,3
180 specifying AUTH.
182
184 This collection of options are common to many programs and provide in‐
185 formation that many users may expect.
186 • -h, --help=[man|no-man]: Display the tools manpage. By default, it
188 attempts to invoke the manpager for the tool, however, on failure
189 will output a short tool summary. This is the same behavior if the
190 “man” option argument is specified, however if explicit “man” is re‐
191 quested, the tool will provide errors from man on stderr. If the
192 “no-man” option if specified, or the manpager fails, the short op‐
193 tions will be output to stdout.
194 To successfully use the manpages feature requires the manpages to be
196 installed or on MANPATH, See man(1) for more details.
197 • -v, --version: Display version information for this tool, supported
199 tctis and exit.
200 • -V, --verbose: Increase the information that the tool prints to the
202 console during its execution. When using this option the file and
203 line number are printed.
204 • -Q, --quiet: Silence normal tool output to stdout.
206 • -Z, --enable-errata: Enable the application of errata fixups. Useful
208 if an errata fixup needs to be applied to commands sent to the TPM.
209 Defining the environment TPM2TOOLS_ENABLE_ERRATA is equivalent. in‐
210 formation many users may expect.
211
213 The TCTI or “Transmission Interface” is the communication mechanism
214 with the TPM. TCTIs can be changed for communication with TPMs across
215 different mediums.
216 To control the TCTI, the tools respect:
218 1. The command line option -T or --tcti
220 2. The environment variable: TPM2TOOLS_TCTI.
222 Note: The command line option always overrides the environment vari‐
224 able.
225 The current known TCTIs are:
227 • tabrmd - The resource manager, called tabrmd
229 (https://github.com/tpm2-software/tpm2-abrmd). Note that tabrmd and
230 abrmd as a tcti name are synonymous.
231 • mssim - Typically used for communicating to the TPM software simula‐
233 tor.
234 • device - Used when talking directly to a TPM device file.
236 • none - Do not initalize a connection with the TPM. Some tools allow
238 for off-tpm options and thus support not using a TCTI. Tools that do
239 not support it will error when attempted to be used without a TCTI
240 connection. Does not support ANY options and MUST BE presented as
241 the exact text of “none”.
242 The arguments to either the command line option or the environment
244 variable are in the form:
245 <tcti-name>:<tcti-option-config>
247 Specifying an empty string for either the <tcti-name> or <tcti-op‐
249 tion-config> results in the default being used for that portion respec‐
250 tively.
251 TCTI Defaults
253 When a TCTI is not specified, the default TCTI is searched for using
254 dlopen(3) semantics. The tools will search for tabrmd, device and
255 mssim TCTIs IN THAT ORDER and USE THE FIRST ONE FOUND. You can query
256 what TCTI will be chosen as the default by using the -v option to print
257 the version information. The “default-tcti” key-value pair will indi‐
258 cate which of the aforementioned TCTIs is the default.
259 Custom TCTIs
261 Any TCTI that implements the dynamic TCTI interface can be loaded. The
262 tools internally use dlopen(3), and the raw tcti-name value is used for
263 the lookup. Thus, this could be a path to the shared library, or a li‐
264 brary name as understood by dlopen(3) semantics.
265
267 This collection of options are used to configure the various known TCTI
268 modules available:
269 • device: For the device TCTI, the TPM character device file for use by
271 the device TCTI can be specified. The default is /dev/tpm0.
272 Example: -T device:/dev/tpm0 or export TPM2TOOLS_TCTI=“de‐
274 vice:/dev/tpm0”
275 • mssim: For the mssim TCTI, the domain name or IP address and port
277 number used by the simulator can be specified. The default are
278 127.0.0.1 and 2321.
279 Example: -T mssim:host=localhost,port=2321 or export TPM2TOOLS_TC‐
281 TI=“mssim:host=localhost,port=2321”
282 • abrmd: For the abrmd TCTI, the configuration string format is a se‐
284 ries of simple key value pairs separated by a `,' character. Each
285 key and value string are separated by a `=' character.
286 • TCTI abrmd supports two keys:
288 1. `bus_name' : The name of the tabrmd service on the bus (a
290 string).
291 2. `bus_type' : The type of the dbus instance (a string) limited to
293 `session' and `system'.
294 Specify the tabrmd tcti name and a config string of bus_name=com.ex‐
296 ample.FooBar:
297 \--tcti=tabrmd:bus_name=com.example.FooBar
299 Specify the default (abrmd) tcti and a config string of bus_type=ses‐
301 sion:
302 \--tcti:bus_type=session
304 NOTE: abrmd and tabrmd are synonymous. the various known TCTI mod‐
306 ules.
307
309 OR 0xbadc0de into an index of 0’s
310 tpm2_nvdefine -C o -a "nt=bits|ownerread|policywrite|ownerwrite|writedefine" 1
311 tpm2_nvsetbits -C o -i 0xbadc0de 1
313 tpm2_nvread -C o 1 | xxd -p | sed s/'^0*'/0x/
315 0xbadc0de
316
318 Tools can return any of the following codes:
319 • 0 - Success.
321 • 1 - General non-specific error.
323 • 2 - Options handling error.
325 • 3 - Authentication error.
327 • 4 - TCTI related error.
329 • 5 - Non supported scheme. Applicable to tpm2_testparams.
331
333 Github Issues (https://github.com/tpm2-software/tpm2-tools/issues)
334
336 See the Mailing List (https://lists.linuxfoundation.org/mailman/listin‐
337 fo/tpm2)
338tpm2-tools tpm2_nvsetbits(1)