1tpm2_nvundefine(1) General Commands Manual tpm2_nvundefine(1)
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6 tpm2_nvundefine(1) - Undefine a Non-Volatile (NV) index.
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9 tpm2_nvundefine [OPTIONS] [ARGUMENT]
10
12 tpm2_nvundefine(1) - Undefine a Non-Volatile (NV) index that was previ‐
13 ously defined with tpm2_nvdefine(1). The index is specified as an ar‐
14 gument. It can be specified as raw handle or an offset value to the nv
15 handle range "TPM2_HR_NV_INDEX".
16
18 · -C, --hierarchy=OBJECT:
19 Specifies the hierarchy used to authorize. Supported options are:
20 · o for TPM_RH_OWNER
22 · p for TPM_RH_PLATFORM
24 · <num> where a hierarchy handle may be specified.
26 · -P, --auth=AUTH:
28 Specifies the authorization value for the hierarchy.
30 · ARGUMENT the command line argument specifies the NV index or offset
32 number.
33 References
36 The type of a context object, whether it is a handle or file name, is
37 determined according to the following logic in-order:
38 · If the argument is a file path, then the file is loaded as a restored
40 TPM transient object.
41 · If the argument is a prefix match on one of:
43 · owner: the owner hierarchy
45 · platform: the platform hierarchy
47 · endorsement: the endorsement hierarchy
49 · lockout: the lockout control persistent object
51 · If the argument argument can be loaded as a number it will be treat
53 as a handle, e.g. 0x81010013 and used directly.OBJECT.
54
56 Authorization for use of an object in TPM2.0 can come in 3 different
57 forms: 1. Password 2. HMAC 3. Sessions
58 NOTE: "Authorizations default to the EMPTY PASSWORD when not speci‐
60 fied".
61 Passwords
63 Passwords are interpreted in the following forms below using prefix
64 identifiers.
65 Note: By default passwords are assumed to be in the string form when
67 they do not have a prefix.
68 String
70 A string password, specified by prefix "str:" or it's absence (raw
71 string without prefix) is not interpreted, and is directly used for au‐
72 thorization.
73 Examples
75 foobar
76 str:foobar
77 Hex-string
79 A hex-string password, specified by prefix "hex:" is converted from a
80 hexidecimal form into a byte array form, thus allowing passwords with
81 non-printable and/or terminal un-friendly characters.
82 Example
84 hex:0x1122334455667788
85 File
87 A file based password, specified be prefix "file:" should be the path
88 of a file containing the password to be read by the tool or a "-" to
89 use stdin. Storing passwords in files prevents information leakage,
90 passwords passed as options can be read from the process list or common
91 shell history features.
92 Examples
94 # to use stdin and be prompted
95 file:-
96 # to use a file from a path
98 file:path/to/password/file
99 # to echo a password via stdin:
101 echo foobar | tpm2_tool -p file:-
102 # to use a bash here-string via stdin:
104 tpm2_tool -p file:- <<< foobar
106 Sessions
108 When using a policy session to authorize the use of an object, prefix
109 the option argument with the session keyword. Then indicate a path to
110 a session file that was created with tpm2_startauthsession(1). Option‐
111 ally, if the session requires an auth value to be sent with the session
112 handle (eg policy password), then append a + and a string as described
113 in the Passwords section.
114 Examples
116 To use a session context file called session.ctx.
117 session:session.ctx
119 To use a session context file called session.ctx AND send the authvalue
121 mypassword.
122 session:session.ctx+mypassword
124 To use a session context file called session.ctx AND send the HEX auth‐
126 value 0x11223344.
127 session:session.ctx+hex:11223344
129 PCR Authorizations
131 You can satisfy a PCR policy using the "pcr:" prefix and the PCR mini‐
132 language. The PCR minilanguage is as follows:
133 <pcr-spec>=<raw-pcr-file>
134 The PCR spec is documented in in the section "PCR bank specifiers".
136 The raw-pcr-file is an optional the output of the raw PCR contents as
138 returned by tpm2_pcrread(1).
139 PCR bank specifiers (common/pcr.md)
141 Examples
143 To satisfy a PCR policy of sha256 on banks 0, 1, 2 and 3 use a specifi‐
144 er of:
145 pcr:sha256:0,1,2,3
147 specifying AUTH.
149
151 This collection of options are common to many programs and provide in‐
152 formation that many users may expect.
153 · -h, --help=[man|no-man]: Display the tools manpage. By default, it
155 attempts to invoke the manpager for the tool, however, on failure
156 will output a short tool summary. This is the same behavior if the
157 "man" option argument is specified, however if explicit "man" is re‐
158 quested, the tool will provide errors from man on stderr. If the
159 "no-man" option if specified, or the manpager fails, the short op‐
160 tions will be output to stdout.
161 To successfully use the manpages feature requires the manpages to be
163 installed or on MANPATH, See man(1) for more details.
164 · -v, --version: Display version information for this tool, supported
166 tctis and exit.
167 · -V, --verbose: Increase the information that the tool prints to the
169 console during its execution. When using this option the file and
170 line number are printed.
171 · -Q, --quiet: Silence normal tool output to stdout.
173 · -Z, --enable-errata: Enable the application of errata fixups. Useful
175 if an errata fixup needs to be applied to commands sent to the TPM.
176 Defining the environment TPM2TOOLS_ENABLE_ERRATA is equivalent. in‐
177 formation many users may expect.
178
180 The TCTI or "Transmission Interface" is the communication mechanism
181 with the TPM. TCTIs can be changed for communication with TPMs across
182 different mediums.
183 To control the TCTI, the tools respect:
185 1. The command line option -T or --tcti
187 2. The environment variable: TPM2TOOLS_TCTI.
189 Note: The command line option always overrides the environment vari‐
191 able.
192 The current known TCTIs are:
194 · tabrmd - The resource manager, called tabrmd
196 (https://github.com/tpm2-software/tpm2-abrmd). Note that tabrmd and
197 abrmd as a tcti name are synonymous.
198 · mssim - Typically used for communicating to the TPM software simula‐
200 tor.
201 · device - Used when talking directly to a TPM device file.
203 · none - Do not initalize a connection with the TPM. Some tools allow
205 for off-tpm options and thus support not using a TCTI. Tools that do
206 not support it will error when attempted to be used without a TCTI
207 connection. Does not support ANY options and MUST BE presented as
208 the exact text of "none".
209 The arguments to either the command line option or the environment
211 variable are in the form:
212 <tcti-name>:<tcti-option-config>
214 Specifying an empty string for either the <tcti-name> or <tcti-op‐
216 tion-config> results in the default being used for that portion respec‐
217 tively.
218 TCTI Defaults
220 When a TCTI is not specified, the default TCTI is searched for using
221 dlopen(3) semantics. The tools will search for tabrmd, device and
222 mssim TCTIs IN THAT ORDER and USE THE FIRST ONE FOUND. You can query
223 what TCTI will be chosen as the default by using the -v option to print
224 the version information. The "default-tcti" key-value pair will indi‐
225 cate which of the aforementioned TCTIs is the default.
226 Custom TCTIs
228 Any TCTI that implements the dynamic TCTI interface can be loaded. The
229 tools internally use dlopen(3), and the raw tcti-name value is used for
230 the lookup. Thus, this could be a path to the shared library, or a li‐
231 brary name as understood by dlopen(3) semantics.
232
234 This collection of options are used to configure the various known TCTI
235 modules available:
236 · device: For the device TCTI, the TPM character device file for use by
238 the device TCTI can be specified. The default is /dev/tpm0.
239 Example: -T device:/dev/tpm0 or export TPM2TOOLS_TCTI="de‐
241 vice:/dev/tpm0"
242 · mssim: For the mssim TCTI, the domain name or IP address and port
244 number used by the simulator can be specified. The default are
245 127.0.0.1 and 2321.
246 Example: -T mssim:host=localhost,port=2321 or export TPM2TOOLS_TC‐
248 TI="mssim:host=localhost,port=2321"
249 · abrmd: For the abrmd TCTI, the configuration string format is a se‐
251 ries of simple key value pairs separated by a ',' character. Each
252 key and value string are separated by a '=' character.
253 · TCTI abrmd supports two keys:
255 1. 'bus_name' : The name of the tabrmd service on the bus (a
257 string).
258 2. 'bus_type' : The type of the dbus instance (a string) limited to
260 'session' and 'system'.
261 Specify the tabrmd tcti name and a config string of bus_name=com.ex‐
263 ample.FooBar:
264 \--tcti=tabrmd:bus_name=com.example.FooBar
266 Specify the default (abrmd) tcti and a config string of bus_type=ses‐
268 sion:
269 \--tcti:bus_type=session
271 NOTE: abrmd and tabrmd are synonymous. the various known TCTI mod‐
273 ules.
274
276 tpm2_nvdefine 0x1500016 -C 0x40000001 -s 32 -a 0x2000A
277 tpm2_nvundefine 0x1500016 -C 0x40000001
279
281 Tools can return any of the following codes:
282 · 0 - Success.
284 · 1 - General non-specific error.
286 · 2 - Options handling error.
288 · 3 - Authentication error.
290 · 4 - TCTI related error.
292 · 5 - Non supported scheme. Applicable to tpm2_testparams.
294
296 Github Issues (https://github.com/tpm2-software/tpm2-tools/issues)
297
299 See the Mailing List (https://lists.01.org/mailman/listinfo/tpm2)
300tpm2-tools tpm2_nvundefine(1)