1tpm2_nvextend(1) General Commands Manual tpm2_nvextend(1)
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6 tpm2_nvextend(1) - Extend an Non-Volatile (NV) index like it was a PCR.
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9 tpm2_nvextend [OPTIONS] [ARGUMENT]
10
12 tpm2_nvextend(1) - Extend an Non-Volatile (NV) index like it was a PCR.
13 The NV index must be of type "extend" which is specified via the "nt"
14 field when creating the NV space with tpm2_nvdefine(1). The index can
15 be specified as raw handle or an offset value to the NV handle range
16 "TPM2_HR_NV_INDEX" as an argument.
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, --input=FILE:
37 Specifies the input file with data to extend to the NV index.
39 • --cphash=FILE
41 File path to record the hash of the command parameters. This is com‐
43 monly termed as cpHash. NOTE: When this option is selected, The tool
44 will not actually execute the command, it simply returns a cpHash,
45 unless rphash is also required.
46 • --rphash=FILE
48 File path to record the hash of the response parameters. This is
50 commonly termed as rpHash.
51 • -S, --session=FILE:
53 The session created using tpm2_startauthsession. Multiple of these
55 can be specified. For example, you can have one session for auditing
56 and another for encryption/decryption of the parameters.
57 • ARGUMENT the command line argument specifies the NV index or offset
59 number.
60 References
63 The type of a context object, whether it is a handle or file name, is
64 determined according to the following logic in-order:
65 • If the argument is a file path, then the file is loaded as a restored
67 TPM transient object.
68 • If the argument is a prefix match on one of:
70 • owner: the owner hierarchy
72 • platform: the platform hierarchy
74 • endorsement: the endorsement hierarchy
76 • lockout: the lockout control persistent object
78 • If the argument argument can be loaded as a number it will be treat
80 as a handle, e.g. 0x81010013 and used directly.OBJECT.
81
83 Authorization for use of an object in TPM2.0 can come in 3 different
84 forms: 1. Password 2. HMAC 3. Sessions
85 NOTE: "Authorizations default to the EMPTY PASSWORD when not speci‐
87 fied".
88 Passwords
90 Passwords are interpreted in the following forms below using prefix
91 identifiers.
92 Note: By default passwords are assumed to be in the string form when
94 they do not have a prefix.
95 String
97 A string password, specified by prefix "str:" or it's absence (raw
98 string without prefix) is not interpreted, and is directly used for au‐
99 thorization.
100 Examples
102 foobar
103 str:foobar
104 Hex-string
106 A hex-string password, specified by prefix "hex:" is converted from a
107 hexidecimal form into a byte array form, thus allowing passwords with
108 non-printable and/or terminal un-friendly characters.
109 Example
111 hex:0x1122334455667788
112 File
114 A file based password, specified be prefix "file:" should be the path
115 of a file containing the password to be read by the tool or a "-" to
116 use stdin. Storing passwords in files prevents information leakage,
117 passwords passed as options can be read from the process list or common
118 shell history features.
119 Examples
121 # to use stdin and be prompted
122 file:-
123 # to use a file from a path
125 file:path/to/password/file
126 # to echo a password via stdin:
128 echo foobar | tpm2_tool -p file:-
129 # to use a bash here-string via stdin:
131 tpm2_tool -p file:- <<< foobar
133 Sessions
135 When using a policy session to authorize the use of an object, prefix
136 the option argument with the session keyword. Then indicate a path to
137 a session file that was created with tpm2_startauthsession(1). Option‐
138 ally, if the session requires an auth value to be sent with the session
139 handle (eg policy password), then append a + and a string as described
140 in the Passwords section.
141 Examples
143 To use a session context file called session.ctx.
144 session:session.ctx
146 To use a session context file called session.ctx AND send the authvalue
148 mypassword.
149 session:session.ctx+mypassword
151 To use a session context file called session.ctx AND send the HEX auth‐
153 value 0x11223344.
154 session:session.ctx+hex:11223344
156 PCR Authorizations
158 You can satisfy a PCR policy using the "pcr:" prefix and the PCR mini‐
159 language. The PCR minilanguage is as follows:
160 <pcr-spec>=<raw-pcr-file>
161 The PCR spec is documented in in the section "PCR bank specifiers".
163 The raw-pcr-file is an optional the output of the raw PCR contents as
165 returned by tpm2_pcrread(1).
166 PCR bank specifiers (common/pcr.md)
168 Examples
170 To satisfy a PCR policy of sha256 on banks 0, 1, 2 and 3 use a specifi‐
171 er of:
172 pcr:sha256:0,1,2,3
174 specifying AUTH.
176
178 This collection of options are common to many programs and provide in‐
179 formation that many users may expect.
180 • -h, --help=[man|no-man]: Display the tools manpage. By default, it
182 attempts to invoke the manpager for the tool, however, on failure
183 will output a short tool summary. This is the same behavior if the
184 "man" option argument is specified, however if explicit "man" is re‐
185 quested, the tool will provide errors from man on stderr. If the
186 "no-man" option if specified, or the manpager fails, the short op‐
187 tions will be output to stdout.
188 To successfully use the manpages feature requires the manpages to be
190 installed or on MANPATH, See man(1) for more details.
191 • -v, --version: Display version information for this tool, supported
193 tctis and exit.
194 • -V, --verbose: Increase the information that the tool prints to the
196 console during its execution. When using this option the file and
197 line number are printed.
198 • -Q, --quiet: Silence normal tool output to stdout.
200 • -Z, --enable-errata: Enable the application of errata fixups. Useful
202 if an errata fixup needs to be applied to commands sent to the TPM.
203 Defining the environment TPM2TOOLS_ENABLE_ERRATA is equivalent. in‐
204 formation many users may expect.
205
207 The TCTI or "Transmission Interface" is the communication mechanism
208 with the TPM. TCTIs can be changed for communication with TPMs across
209 different mediums.
210 To control the TCTI, the tools respect:
212 1. The command line option -T or --tcti
214 2. The environment variable: TPM2TOOLS_TCTI.
216 Note: The command line option always overrides the environment vari‐
218 able.
219 The current known TCTIs are:
221 • tabrmd - The resource manager, called tabrmd
223 (https://github.com/tpm2-software/tpm2-abrmd). Note that tabrmd and
224 abrmd as a tcti name are synonymous.
225 • mssim - Typically used for communicating to the TPM software simula‐
227 tor.
228 • device - Used when talking directly to a TPM device file.
230 • none - Do not initalize a connection with the TPM. Some tools allow
232 for off-tpm options and thus support not using a TCTI. Tools that do
233 not support it will error when attempted to be used without a TCTI
234 connection. Does not support ANY options and MUST BE presented as
235 the exact text of "none".
236 The arguments to either the command line option or the environment
238 variable are in the form:
239 <tcti-name>:<tcti-option-config>
241 Specifying an empty string for either the <tcti-name> or <tcti-op‐
243 tion-config> results in the default being used for that portion respec‐
244 tively.
245 TCTI Defaults
247 When a TCTI is not specified, the default TCTI is searched for using
248 dlopen(3) semantics. The tools will search for tabrmd, device and
249 mssim TCTIs IN THAT ORDER and USE THE FIRST ONE FOUND. You can query
250 what TCTI will be chosen as the default by using the -v option to print
251 the version information. The "default-tcti" key-value pair will indi‐
252 cate which of the aforementioned TCTIs is the default.
253 Custom TCTIs
255 Any TCTI that implements the dynamic TCTI interface can be loaded. The
256 tools internally use dlopen(3), and the raw tcti-name value is used for
257 the lookup. Thus, this could be a path to the shared library, or a li‐
258 brary name as understood by dlopen(3) semantics.
259
261 This collection of options are used to configure the various known TCTI
262 modules available:
263 • device: For the device TCTI, the TPM character device file for use by
265 the device TCTI can be specified. The default is /dev/tpm0.
266 Example: -T device:/dev/tpm0 or export TPM2TOOLS_TCTI="de‐
268 vice:/dev/tpm0"
269 • mssim: For the mssim TCTI, the domain name or IP address and port
271 number used by the simulator can be specified. The default are
272 127.0.0.1 and 2321.
273 Example: -T mssim:host=localhost,port=2321 or export TPM2TOOLS_TC‐
275 TI="mssim:host=localhost,port=2321"
276 • abrmd: For the abrmd TCTI, the configuration string format is a se‐
278 ries of simple key value pairs separated by a ',' character. Each
279 key and value string are separated by a '=' character.
280 • TCTI abrmd supports two keys:
282 1. 'bus_name' : The name of the tabrmd service on the bus (a
284 string).
285 2. 'bus_type' : The type of the dbus instance (a string) limited to
287 'session' and 'system'.
288 Specify the tabrmd tcti name and a config string of bus_name=com.ex‐
290 ample.FooBar:
291 \--tcti=tabrmd:bus_name=com.example.FooBar
293 Specify the default (abrmd) tcti and a config string of bus_type=ses‐
295 sion:
296 \--tcti:bus_type=session
298 NOTE: abrmd and tabrmd are synonymous. the various known TCTI mod‐
300 ules.
301
303 OR 0xbadc0de into an index of 0's
304 tpm2_nvdefine -C o -a "nt=extend|ownerread|policywrite|ownerwrite|writedefine" 1
305 echo 'my data' | tpm2_nvextend -C o -i- 1
307 tpm2_nvread -C o 1 | xxd -p -c32
309 db7472e3fe3309b011ec11565bce4ea6668cc8ecdef7e6fdcda5206687af3f43
310
312 Tools can return any of the following codes:
313 • 0 - Success.
315 • 1 - General non-specific error.
317 • 2 - Options handling error.
319 • 3 - Authentication error.
321 • 4 - TCTI related error.
323 • 5 - Non supported scheme. Applicable to tpm2_testparams.
325
327 Github Issues (https://github.com/tpm2-software/tpm2-tools/issues)
328
330 See the Mailing List (https://lists.01.org/mailman/listinfo/tpm2)
331tpm2-tools tpm2_nvextend(1)