1tpm2_commit(1) General Commands Manual tpm2_commit(1)
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6 tpm2_commit(1) - Performs the first part of an ECC anonymous signing
7 operation.
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10 tpm2_commit [OPTIONS]
11
13 tpm2_commit(1) - Performs the first part of an ECC anonymous signing
14 operation. The TPM will perform the point multiplications on the pro‐
15 vided points and return intermediate signing values. The signing key
16 is an ECC key. The key cannot be a sign+decrypt key and must have an
17 anonymous signing scheme. TPM_ALG_ECDAA is the only supported anony‐
18 mous scheme.
19
21 • ARGUMENT=FILE:
22 Specify the input data used to derive the x coordinate of the base‐
24 point.
25 • --basepoint-y=FILE:
27 Specify the y coordinate of the basepoint.
29 • --eccpoint-P=FILE:
31 Specify a point on the curve used by sign handle.
33 • --eccpoint-K=FILE:
35 Output ECC point K ≔ [ds](x2, y2).
37 • --eccpoint-L=FILE:
39 Output ECC point L ≔ [r](x2, y2).
41 • -u, --public=FILE:
43 Output ECC point E ≔ [r]P1.
45 • -t, --counter=FILE
47 Specify file path to save the least-significant 16 bits of commit
49 count.
50 • -p, --auth=AUTH:
52 The authorization value for the created object.
54 • -c, --context=FILE:
56 Context object pointing to the the key used for signing. Either a
58 file or a handle number. See section “Context Object Format”.
59 References
62 Options that take algorithms support “nice-names”.
63 There are two major algorithm specification string classes, simple and
65 complex. Only certain algorithms will be accepted by the TPM, based on
66 usage and conditions.
67 Simple specifiers
69 These are strings with no additional specification data. When creating
70 objects, non-specified portions of an object are assumed to defaults.
71 You can find the list of known “Simple Specifiers Below”.
72 Asymmetric
74 • rsa
75 • ecc
77 Symmetric
79 • aes
80 • camellia
82 Hashing Algorithms
84 • sha1
85 • sha256
87 • sha384
89 • sha512
91 • sm3_256
93 • sha3_256
95 • sha3_384
97 • sha3_512
99 Keyed Hash
101 • hmac
102 • xor
104 Signing Schemes
106 • rsassa
107 • rsapss
109 • ecdsa
111 • ecdaa
113 • ecschnorr
115 Asymmetric Encryption Schemes
117 • oaep
118 • rsaes
120 • ecdh
122 Modes
124 • ctr
125 • ofb
127 • cbc
129 • cfb
131 • ecb
133 Misc
135 • null
136 Complex Specifiers
138 Objects, when specified for creation by the TPM, have numerous algo‐
139 rithms to populate in the public data. Things like type, scheme and
140 asymmetric details, key size, etc. Below is the general format for
141 specifying this data: <type>:<scheme>:<symmetric-details>
142 Type Specifiers
144 This portion of the complex algorithm specifier is required. The re‐
145 maining scheme and symmetric details will default based on the type
146 specified and the type of the object being created.
147 • aes - Default AES: aes128
149 • aes128<mode> - 128 bit AES with optional mode (ctr|ofb|cbc|cfb|ecb).
151 If mode is not specified, defaults to null.
152 • aes192<mode> - Same as aes128<mode>, except for a 192 bit key size.
154 • aes256<mode> - Same as aes128<mode>, except for a 256 bit key size.
156 • ecc - Elliptical Curve, defaults to ecc256.
158 • ecc192 - 192 bit ECC
160 • ecc224 - 224 bit ECC
162 • ecc256 - 256 bit ECC
164 • ecc384 - 384 bit ECC
166 • ecc521 - 521 bit ECC
168 • rsa - Default RSA: rsa2048
170 • rsa1024 - RSA with 1024 bit keysize.
172 • rsa2048 - RSA with 2048 bit keysize.
174 • rsa4096 - RSA with 4096 bit keysize.
176 Scheme Specifiers
178 Next, is an optional field, it can be skipped.
179 Schemes are usually Signing Schemes or Asymmetric Encryption Schemes.
181 Most signing schemes take a hash algorithm directly following the sign‐
182 ing scheme. If the hash algorithm is missing, it defaults to sha256.
183 Some take no arguments, and some take multiple arguments.
184 Hash Optional Scheme Specifiers
186 These scheme specifiers are followed by a dash and a valid hash algo‐
187 rithm, For example: oaep-sha256.
188 • oaep
190 • ecdh
192 • rsassa
194 • rsapss
196 • ecdsa
198 • ecschnorr
200 Multiple Option Scheme Specifiers
202 This scheme specifier is followed by a count (max size UINT16) then
203 followed by a dash(-) and a valid hash algorithm. * ecdaa For example,
204 ecdaa4-sha256. If no count is specified, it defaults to 4.
205 No Option Scheme Specifiers
207 This scheme specifier takes NO arguments. * rsaes
208 Symmetric Details Specifiers
210 This field is optional, and defaults based on the type of object being
211 created and it’s attributes. Generally, any valid Symmetric specifier
212 from the Type Specifiers list should work. If not specified, an asym‐
213 metric objects symmetric details defaults to aes128cfb.
214 Examples
216 Create an rsa2048 key with an rsaes asymmetric encryption scheme
217 tpm2_create -C parent.ctx -G rsa2048:rsaes -u key.pub -r key.priv
218 Create an ecc256 key with an ecdaa signing scheme with a count of 4 and
220 sha384 hash
221 /tpm2_create -C parent.ctx -G ecc256:ecdaa4-sha384 -u key.pub -r
222 key.priv cryptographic algorithms ALGORITHM.
223
225 This collection of options are common to many programs and provide in‐
226 formation that many users may expect.
227 • -h, --help=[man|no-man]: Display the tools manpage. By default, it
229 attempts to invoke the manpager for the tool, however, on failure
230 will output a short tool summary. This is the same behavior if the
231 “man” option argument is specified, however if explicit “man” is re‐
232 quested, the tool will provide errors from man on stderr. If the
233 “no-man” option if specified, or the manpager fails, the short op‐
234 tions will be output to stdout.
235 To successfully use the manpages feature requires the manpages to be
237 installed or on MANPATH, See man(1) for more details.
238 • -v, --version: Display version information for this tool, supported
240 tctis and exit.
241 • -V, --verbose: Increase the information that the tool prints to the
243 console during its execution. When using this option the file and
244 line number are printed.
245 • -Q, --quiet: Silence normal tool output to stdout.
247 • -Z, --enable-errata: Enable the application of errata fixups. Useful
249 if an errata fixup needs to be applied to commands sent to the TPM.
250 Defining the environment TPM2TOOLS_ENABLE_ERRATA is equivalent. in‐
251 formation many users may expect.
252
254 The TCTI or “Transmission Interface” is the communication mechanism
255 with the TPM. TCTIs can be changed for communication with TPMs across
256 different mediums.
257 To control the TCTI, the tools respect:
259 1. The command line option -T or --tcti
261 2. The environment variable: TPM2TOOLS_TCTI.
263 Note: The command line option always overrides the environment vari‐
265 able.
266 The current known TCTIs are:
268 • tabrmd - The resource manager, called tabrmd
270 (https://github.com/tpm2-software/tpm2-abrmd). Note that tabrmd and
271 abrmd as a tcti name are synonymous.
272 • mssim - Typically used for communicating to the TPM software simula‐
274 tor.
275 • device - Used when talking directly to a TPM device file.
277 • none - Do not initalize a connection with the TPM. Some tools allow
279 for off-tpm options and thus support not using a TCTI. Tools that do
280 not support it will error when attempted to be used without a TCTI
281 connection. Does not support ANY options and MUST BE presented as
282 the exact text of “none”.
283 The arguments to either the command line option or the environment
285 variable are in the form:
286 <tcti-name>:<tcti-option-config>
288 Specifying an empty string for either the <tcti-name> or <tcti-op‐
290 tion-config> results in the default being used for that portion respec‐
291 tively.
292 TCTI Defaults
294 When a TCTI is not specified, the default TCTI is searched for using
295 dlopen(3) semantics. The tools will search for tabrmd, device and
296 mssim TCTIs IN THAT ORDER and USE THE FIRST ONE FOUND. You can query
297 what TCTI will be chosen as the default by using the -v option to print
298 the version information. The “default-tcti” key-value pair will indi‐
299 cate which of the aforementioned TCTIs is the default.
300 Custom TCTIs
302 Any TCTI that implements the dynamic TCTI interface can be loaded. The
303 tools internally use dlopen(3), and the raw tcti-name value is used for
304 the lookup. Thus, this could be a path to the shared library, or a li‐
305 brary name as understood by dlopen(3) semantics.
306
308 This collection of options are used to configure the various known TCTI
309 modules available:
310 • device: For the device TCTI, the TPM character device file for use by
312 the device TCTI can be specified. The default is /dev/tpm0.
313 Example: -T device:/dev/tpm0 or export TPM2TOOLS_TCTI=“de‐
315 vice:/dev/tpm0”
316 • mssim: For the mssim TCTI, the domain name or IP address and port
318 number used by the simulator can be specified. The default are
319 127.0.0.1 and 2321.
320 Example: -T mssim:host=localhost,port=2321 or export TPM2TOOLS_TC‐
322 TI=“mssim:host=localhost,port=2321”
323 • abrmd: For the abrmd TCTI, the configuration string format is a se‐
325 ries of simple key value pairs separated by a `,' character. Each
326 key and value string are separated by a `=' character.
327 • TCTI abrmd supports two keys:
329 1. `bus_name' : The name of the tabrmd service on the bus (a
331 string).
332 2. `bus_type' : The type of the dbus instance (a string) limited to
334 `session' and `system'.
335 Specify the tabrmd tcti name and a config string of bus_name=com.ex‐
337 ample.FooBar:
338 \--tcti=tabrmd:bus_name=com.example.FooBar
340 Specify the default (abrmd) tcti and a config string of bus_type=ses‐
342 sion:
343 \--tcti:bus_type=session
345 NOTE: abrmd and tabrmd are synonymous. the various known TCTI mod‐
347 ules.
348
350 tpm2_createprimary -C o -c prim.ctx -Q
351 tpm2_create -C prim.ctx -c key.ctx -u key.pub -r key.priv -G ecc256:ecdaa
353 tpm2_commit -c key.ctx -t count.er \
355 --eccpoint-K K.bin --eccpoint-L L.bin -u E.bin
356
358 Tools can return any of the following codes:
359 • 0 - Success.
361 • 1 - General non-specific error.
363 • 2 - Options handling error.
365 • 3 - Authentication error.
367 • 4 - TCTI related error.
369 • 5 - Non supported scheme. Applicable to tpm2_testparams.
371
373 Github Issues (https://github.com/tpm2-software/tpm2-tools/issues)
374
376 See the Mailing List (https://lists.01.org/mailman/listinfo/tpm2)
377tpm2-tools tpm2_commit(1)