1tpm2_nvincrement(1) General Commands Manual tpm2_nvincrement(1)
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6 tpm2_nvincrement(1) - Increment counter in a Non-Volatile (NV) index.
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9 tpm2_nvincrement [OPTIONS] [ARGUMENT]
10
12 tpm2_nvincrement(1) - Increment value of a Non-Volatile (NV) index set‐
13 up as a counter. The index can be specified as raw handle or an offset
14 value to the nv handle range “TPM2_HR_NV_INDEX”.
15
17 • -C, --hierarchy=OBJECT:
18 Specifies the hierarchy used to authorize. Supported options are:
19 • o for TPM_RH_OWNER
21 • p for TPM_RH_PLATFORM
23 • <num> where a hierarchy handle or nv-index may be used.
25 When -C isn’t explicitly passed the index handle will be used to au‐
27 thorize against the index. The index auth value is set via the -p
28 option to tpm2_nvdefine(1).
29 • -P, --auth=AUTH:
31 Specifies the authorization value for the hierarchy.
33 • --cphash=FILE
35 File path to record the hash of the command parameters. This is com‐
37 monly termed as cpHash. NOTE: When this option is selected, The tool
38 will not actually execute the command, it simply returns a cpHash un‐
39 less rphash is also required.
40 • --rphash=FILE
42 File path to record the hash of the response parameters. This is
44 commonly termed as rpHash.
45 • -S, --session=FILE:
47 The session created using tpm2_startauthsession. This can be used to
49 specify an auxiliary session for auditing and or encryption/decryp‐
50 tion of the parameters.
51 • -n, --name=FILE:
53 The name of the NV index that must be provided when only calculating
55 the cpHash without actually dispatching the command to the TPM.
56 • ARGUMENT the command line argument specifies the NV index or offset
58 number.
59 References
62 The type of a context object, whether it is a handle or file name, is
63 determined according to the following logic in-order:
64 • If the argument is a file path, then the file is loaded as a restored
66 TPM transient object.
67 • If the argument is a prefix match on one of:
69 • owner: the owner hierarchy
71 • platform: the platform hierarchy
73 • endorsement: the endorsement hierarchy
75 • lockout: the lockout control persistent object
77 • If the argument argument can be loaded as a number it will be treat
79 as a handle, e.g. 0x81010013 and used directly._OBJECT_.
80
82 Authorization for use of an object in TPM2.0 can come in 3 different
83 forms: 1. Password 2. HMAC 3. Sessions
84 NOTE: “Authorizations default to the EMPTY PASSWORD when not speci‐
86 fied”.
87 Passwords
89 Passwords are interpreted in the following forms below using prefix
90 identifiers.
91 Note: By default passwords are assumed to be in the string form when
93 they do not have a prefix.
94 String
96 A string password, specified by prefix “str:” or it’s absence (raw
97 string without prefix) is not interpreted, and is directly used for au‐
98 thorization.
99 Examples
101 foobar
102 str:foobar
103 Hex-string
105 A hex-string password, specified by prefix “hex:” is converted from a
106 hexidecimal form into a byte array form, thus allowing passwords with
107 non-printable and/or terminal un-friendly characters.
108 Example
110 hex:1122334455667788
111 File
113 A file based password, specified be prefix “file:” should be the path
114 of a file containing the password to be read by the tool or a “-” to
115 use stdin. Storing passwords in files prevents information leakage,
116 passwords passed as options can be read from the process list or common
117 shell history features.
118 Examples
120 # to use stdin and be prompted
121 file:-
122 # to use a file from a path
124 file:path/to/password/file
125 # to echo a password via stdin:
127 echo foobar | tpm2_tool -p file:-
128 # to use a bash here-string via stdin:
130 tpm2_tool -p file:- <<< foobar
132 Sessions
134 When using a policy session to authorize the use of an object, prefix
135 the option argument with the session keyword. Then indicate a path to
136 a session file that was created with tpm2_startauthsession(1). Option‐
137 ally, if the session requires an auth value to be sent with the session
138 handle (eg policy password), then append a + and a string as described
139 in the Passwords section.
140 Examples
142 To use a session context file called session.ctx.
143 session:session.ctx
145 To use a session context file called session.ctx AND send the authvalue
147 mypassword.
148 session:session.ctx+mypassword
150 To use a session context file called session.ctx AND send the HEX auth‐
152 value 0x11223344.
153 session:session.ctx+hex:11223344
155 PCR Authorizations
157 You can satisfy a PCR policy using the “pcr:” prefix and the PCR mini‐
158 language. The PCR minilanguage is as follows:
159 <pcr-spec>=<raw-pcr-file>
160 The PCR spec is documented in in the section “PCR bank specifiers”.
162 The raw-pcr-file is an optional argument that contains the output of
164 the raw PCR contents as returned by tpm2_pcrread(1).
165 PCR bank specifiers (pcr.md)
167 Examples
169 To satisfy a PCR policy of sha256 on banks 0, 1, 2 and 3 use a specifi‐
170 er of:
171 pcr:sha256:0,1,2,3
173 specifying AUTH.
175
177 This collection of options are common to many programs and provide in‐
178 formation that many users may expect.
179 • -h, --help=[man|no-man]: Display the tools manpage. By default, it
181 attempts to invoke the manpager for the tool, however, on failure
182 will output a short tool summary. This is the same behavior if the
183 “man” option argument is specified, however if explicit “man” is re‐
184 quested, the tool will provide errors from man on stderr. If the
185 “no-man” option if specified, or the manpager fails, the short op‐
186 tions will be output to stdout.
187 To successfully use the manpages feature requires the manpages to be
189 installed or on MANPATH, See man(1) for more details.
190 • -v, --version: Display version information for this tool, supported
192 tctis and exit.
193 • -V, --verbose: Increase the information that the tool prints to the
195 console during its execution. When using this option the file and
196 line number are printed.
197 • -Q, --quiet: Silence normal tool output to stdout.
199 • -Z, --enable-errata: Enable the application of errata fixups. Useful
201 if an errata fixup needs to be applied to commands sent to the TPM.
202 Defining the environment TPM2TOOLS_ENABLE_ERRATA is equivalent. in‐
203 formation many users may expect.
204
206 The TCTI or “Transmission Interface” is the communication mechanism
207 with the TPM. TCTIs can be changed for communication with TPMs across
208 different mediums.
209 To control the TCTI, the tools respect:
211 1. The command line option -T or --tcti
213 2. The environment variable: TPM2TOOLS_TCTI.
215 Note: The command line option always overrides the environment vari‐
217 able.
218 The current known TCTIs are:
220 • tabrmd - The resource manager, called tabrmd
222 (https://github.com/tpm2-software/tpm2-abrmd). Note that tabrmd and
223 abrmd as a tcti name are synonymous.
224 • mssim - Typically used for communicating to the TPM software simula‐
226 tor.
227 • device - Used when talking directly to a TPM device file.
229 • none - Do not initalize a connection with the TPM. Some tools allow
231 for off-tpm options and thus support not using a TCTI. Tools that do
232 not support it will error when attempted to be used without a TCTI
233 connection. Does not support ANY options and MUST BE presented as
234 the exact text of “none”.
235 The arguments to either the command line option or the environment
237 variable are in the form:
238 <tcti-name>:<tcti-option-config>
240 Specifying an empty string for either the <tcti-name> or <tcti-op‐
242 tion-config> results in the default being used for that portion respec‐
243 tively.
244 TCTI Defaults
246 When a TCTI is not specified, the default TCTI is searched for using
247 dlopen(3) semantics. The tools will search for tabrmd, device and
248 mssim TCTIs IN THAT ORDER and USE THE FIRST ONE FOUND. You can query
249 what TCTI will be chosen as the default by using the -v option to print
250 the version information. The “default-tcti” key-value pair will indi‐
251 cate which of the aforementioned TCTIs is the default.
252 Custom TCTIs
254 Any TCTI that implements the dynamic TCTI interface can be loaded. The
255 tools internally use dlopen(3), and the raw tcti-name value is used for
256 the lookup. Thus, this could be a path to the shared library, or a li‐
257 brary name as understood by dlopen(3) semantics.
258
260 This collection of options are used to configure the various known TCTI
261 modules available:
262 • device: For the device TCTI, the TPM character device file for use by
264 the device TCTI can be specified. The default is /dev/tpm0.
265 Example: -T device:/dev/tpm0 or export TPM2TOOLS_TCTI=“de‐
267 vice:/dev/tpm0”
268 • mssim: For the mssim TCTI, the domain name or IP address and port
270 number used by the simulator can be specified. The default are
271 127.0.0.1 and 2321.
272 Example: -T mssim:host=localhost,port=2321 or export TPM2TOOLS_TC‐
274 TI=“mssim:host=localhost,port=2321”
275 • abrmd: For the abrmd TCTI, the configuration string format is a se‐
277 ries of simple key value pairs separated by a `,' character. Each
278 key and value string are separated by a `=' character.
279 • TCTI abrmd supports two keys:
281 1. `bus_name' : The name of the tabrmd service on the bus (a
283 string).
284 2. `bus_type' : The type of the dbus instance (a string) limited to
286 `session' and `system'.
287 Specify the tabrmd tcti name and a config string of bus_name=com.ex‐
289 ample.FooBar:
290 \--tcti=tabrmd:bus_name=com.example.FooBar
292 Specify the default (abrmd) tcti and a config string of bus_type=ses‐
294 sion:
295 \--tcti:bus_type=session
297 NOTE: abrmd and tabrmd are synonymous. the various known TCTI mod‐
299 ules.
300
302 To increment the counter at index 0x150016
303 tpm2_nvdefine -C o -s 8 -a "ownerread|authread|authwrite|nt=1" 0x1500016 -p index
304 tpm2_nvincrement -C 0x1500016 0x1500016 -P "index"
306 tpm2_nvread 0x1500016 -P index | xxd -p
308
310 Tools can return any of the following codes:
311 • 0 - Success.
313 • 1 - General non-specific error.
315 • 2 - Options handling error.
317 • 3 - Authentication error.
319 • 4 - TCTI related error.
321 • 5 - Non supported scheme. Applicable to tpm2_testparams.
323
325 Github Issues (https://github.com/tpm2-software/tpm2-tools/issues)
326
328 See the Mailing List (https://lists.linuxfoundation.org/mailman/listin‐
329 fo/tpm2)
330tpm2-tools tpm2_nvincrement(1)