1tpm2_pcrevent(1) General Commands Manual tpm2_pcrevent(1)
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6 tpm2_pcrevent(1) - Hashes a file and optionally extends a pcr.
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9 tpm2_pcrevent [OPTIONS] FILE PCR_INDEX
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12 tpm2_pcrevent(1) - Hashes FILE if specified or stdin. It uses all of
13 the hashing algorithms that the TPM supports.
14 Optionally, if a PCR index is specified, it extends that PCR for all
16 supported algorithms with the hash digest. FILE and _PCR_INDEX_ argu‐
17 ments don’t need to come in any particular order.
18 In either case, it outputs to stdout the hash algorithm used and the
20 digest value, one per line:
21 alg:digest
23 Where alg is the algorithm used (like sha1) and digest is the digest
25 resulting from the hash computation of alg on the data.
26 See sections 23.1 and sections 17 of the TPM2.0 Specification
28 (https://trustedcomputinggroup.org/wp-content/uploads/TPM-
29 Rev-2.0-Part-3-Commands-01.38.pdf)
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32 These options control extending the pcr:
33 • -P, --auth=AUTH:
35 Specifies the authorization value for PCR.
37
39 This collection of options are common to many programs and provide in‐
40 formation that many users may expect.
41 • -h, --help=[man|no-man]: Display the tools manpage. By default, it
43 attempts to invoke the manpager for the tool, however, on failure
44 will output a short tool summary. This is the same behavior if the
45 “man” option argument is specified, however if explicit “man” is re‐
46 quested, the tool will provide errors from man on stderr. If the
47 “no-man” option if specified, or the manpager fails, the short op‐
48 tions will be output to stdout.
49 To successfully use the manpages feature requires the manpages to be
51 installed or on MANPATH, See man(1) for more details.
52 • -v, --version: Display version information for this tool, supported
54 tctis and exit.
55 • -V, --verbose: Increase the information that the tool prints to the
57 console during its execution. When using this option the file and
58 line number are printed.
59 • -Q, --quiet: Silence normal tool output to stdout.
61 • -Z, --enable-errata: Enable the application of errata fixups. Useful
63 if an errata fixup needs to be applied to commands sent to the TPM.
64 Defining the environment TPM2TOOLS_ENABLE_ERRATA is equivalent.
65
67 The TCTI or “Transmission Interface” is the communication mechanism
68 with the TPM. TCTIs can be changed for communication with TPMs across
69 different mediums.
70 To control the TCTI, the tools respect:
72 1. The command line option -T or --tcti
74 2. The environment variable: TPM2TOOLS_TCTI.
76 Note: The command line option always overrides the environment vari‐
78 able.
79 The current known TCTIs are:
81 • tabrmd - The resource manager, called tabrmd
83 (https://github.com/tpm2-software/tpm2-abrmd). Note that tabrmd and
84 abrmd as a tcti name are synonymous.
85 • mssim - Typically used for communicating to the TPM software simula‐
87 tor.
88 • device - Used when talking directly to a TPM device file.
90 • none - Do not initalize a connection with the TPM. Some tools allow
92 for off-tpm options and thus support not using a TCTI. Tools that do
93 not support it will error when attempted to be used without a TCTI
94 connection. Does not support ANY options and MUST BE presented as
95 the exact text of “none”.
96 The arguments to either the command line option or the environment
98 variable are in the form:
99 <tcti-name>:<tcti-option-config>
101 Specifying an empty string for either the <tcti-name> or <tcti-op‐
103 tion-config> results in the default being used for that portion respec‐
104 tively.
105 TCTI Defaults
107 When a TCTI is not specified, the default TCTI is searched for using
108 dlopen(3) semantics. The tools will search for tabrmd, device and
109 mssim TCTIs IN THAT ORDER and USE THE FIRST ONE FOUND. You can query
110 what TCTI will be chosen as the default by using the -v option to print
111 the version information. The “default-tcti” key-value pair will indi‐
112 cate which of the aforementioned TCTIs is the default.
113 Custom TCTIs
115 Any TCTI that implements the dynamic TCTI interface can be loaded. The
116 tools internally use dlopen(3), and the raw tcti-name value is used for
117 the lookup. Thus, this could be a path to the shared library, or a li‐
118 brary name as understood by dlopen(3) semantics.
119
121 This collection of options are used to configure the various known TCTI
122 modules available:
123 • device: For the device TCTI, the TPM character device file for use by
125 the device TCTI can be specified. The default is /dev/tpm0.
126 Example: -T device:/dev/tpm0 or export TPM2TOOLS_TCTI=“de‐
128 vice:/dev/tpm0”
129 • mssim: For the mssim TCTI, the domain name or IP address and port
131 number used by the simulator can be specified. The default are
132 127.0.0.1 and 2321.
133 Example: -T mssim:host=localhost,port=2321 or export TPM2TOOLS_TC‐
135 TI=“mssim:host=localhost,port=2321”
136 • abrmd: For the abrmd TCTI, the configuration string format is a se‐
138 ries of simple key value pairs separated by a `,' character. Each
139 key and value string are separated by a `=' character.
140 • TCTI abrmd supports two keys:
142 1. `bus_name' : The name of the tabrmd service on the bus (a
144 string).
145 2. `bus_type' : The type of the dbus instance (a string) limited to
147 `session' and `system'.
148 Specify the tabrmd tcti name and a config string of bus_name=com.ex‐
150 ample.FooBar:
151 \--tcti=tabrmd:bus_name=com.example.FooBar
153 Specify the default (abrmd) tcti and a config string of bus_type=ses‐
155 sion:
156 \--tcti:bus_type=session
158 NOTE: abrmd and tabrmd are synonymous.
160
162 Authorization for use of an object in TPM2.0 can come in 3 different
163 forms: 1. Password 2. HMAC 3. Sessions
164 NOTE: “Authorizations default to the EMPTY PASSWORD when not speci‐
166 fied”.
167 Passwords
169 Passwords are interpreted in the following forms below using prefix
170 identifiers.
171 Note: By default passwords are assumed to be in the string form when
173 they do not have a prefix.
174 String
176 A string password, specified by prefix “str:” or it’s absence (raw
177 string without prefix) is not interpreted, and is directly used for au‐
178 thorization.
179 Examples
181 foobar
182 str:foobar
183 Hex-string
185 A hex-string password, specified by prefix “hex:” is converted from a
186 hexidecimal form into a byte array form, thus allowing passwords with
187 non-printable and/or terminal un-friendly characters.
188 Example
190 hex:0x1122334455667788
191 File
193 A file based password, specified be prefix “file:” should be the path
194 of a file containing the password to be read by the tool or a “-” to
195 use stdin. Storing passwords in files prevents information leakage,
196 passwords passed as options can be read from the process list or common
197 shell history features.
198 Examples
200 # to use stdin and be prompted
201 file:-
202 # to use a file from a path
204 file:path/to/password/file
205 # to echo a password via stdin:
207 echo foobar | tpm2_tool -p file:-
208 # to use a bash here-string via stdin:
210 tpm2_tool -p file:- <<< foobar
212 Sessions
214 When using a policy session to authorize the use of an object, prefix
215 the option argument with the session keyword. Then indicate a path to
216 a session file that was created with tpm2_startauthsession(1). Option‐
217 ally, if the session requires an auth value to be sent with the session
218 handle (eg policy password), then append a + and a string as described
219 in the Passwords section.
220 Examples
222 To use a session context file called session.ctx.
223 session:session.ctx
225 To use a session context file called session.ctx AND send the authvalue
227 mypassword.
228 session:session.ctx+mypassword
230 To use a session context file called session.ctx AND send the HEX auth‐
232 value 0x11223344.
233 session:session.ctx+hex:11223344
235 PCR Authorizations
237 You can satisfy a PCR policy using the “pcr:” prefix and the PCR mini‐
238 language. The PCR minilanguage is as follows:
239 <pcr-spec>=<raw-pcr-file>
240 The PCR spec is documented in in the section “PCR bank specifiers”.
242 The raw-pcr-file is an optional argument that contains the output of
244 the raw PCR contents as returned by tpm2_pcrread(1).
245 PCR bank specifiers (pcr.md)
247 Examples
249 To satisfy a PCR policy of sha256 on banks 0, 1, 2 and 3 use a specifi‐
250 er of:
251 pcr:sha256:0,1,2,3
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255 Hash a file
256 echo "foo" > data
257 tpm2_pcrevent data
258 Hash a file and extend PCR 8
260 echo "foo" > data
261 tpm2_pcrevent 8 data
262
264 Tools can return any of the following codes:
265 • 0 - Success.
267 • 1 - General non-specific error.
269 • 2 - Options handling error.
271 • 3 - Authentication error.
273 • 4 - TCTI related error.
275 • 5 - Non supported scheme. Applicable to tpm2_testparams.
277
279 Github Issues (https://github.com/tpm2-software/tpm2-tools/issues)
280
282 See the Mailing List (https://lists.01.org/mailman/listinfo/tpm2)
283tpm2-tools tpm2_pcrevent(1)