1tpm2_geteccparameters(1) General Commands Manual tpm2_geteccparameters(1)
2
6 tpm2_geteccparameters(1) - Retrieves the parameters of an ECC curve
7 identified by its TCG-assigned curveID.
8
10 tpm2_geteccparameters [OPTIONS]
11
13 tpm2_geteccparameters(1) - Retrieves the parameters of an ECC curve
14 identified by its TCG-assigned curveID.
15
17 • ARGUMENT=ALGORITHM:
18 Specify the ECC curve. Example ecc521.
20 • -o, --output=FILE
22 Specify the file path to save the ECC parameters.
24 References
27 Options that take algorithms support “nice-names”.
28 There are two major algorithm specification string classes, simple and
30 complex. Only certain algorithms will be accepted by the TPM, based on
31 usage and conditions.
32 Simple specifiers
34 These are strings with no additional specification data. When creating
35 objects, non-specified portions of an object are assumed to defaults.
36 You can find the list of known “Simple Specifiers Below”.
37 Asymmetric
39 • rsa
40 • ecc
42 Symmetric
44 • aes
45 • camellia
47 Hashing Algorithms
49 • sha1
50 • sha256
52 • sha384
54 • sha512
56 • sm3_256
58 • sha3_256
60 • sha3_384
62 • sha3_512
64 Keyed Hash
66 • hmac
67 • xor
69 Signing Schemes
71 • rsassa
72 • rsapss
74 • ecdsa
76 • ecdaa
78 • ecschnorr
80 Asymmetric Encryption Schemes
82 • oaep
83 • rsaes
85 • ecdh
87 Modes
89 • ctr
90 • ofb
92 • cbc
94 • cfb
96 • ecb
98 Misc
100 • null
101 Complex Specifiers
103 Objects, when specified for creation by the TPM, have numerous algo‐
104 rithms to populate in the public data. Things like type, scheme and
105 asymmetric details, key size, etc. Below is the general format for
106 specifying this data: <type>:<scheme>:<symmetric-details>
107 Type Specifiers
109 This portion of the complex algorithm specifier is required. The re‐
110 maining scheme and symmetric details will default based on the type
111 specified and the type of the object being created.
112 • aes - Default AES: aes128
114 • aes128<mode> - 128 bit AES with optional mode (ctr|ofb|cbc|cfb|ecb).
116 If mode is not specified, defaults to null.
117 • aes192<mode> - Same as aes128<mode>, except for a 192 bit key size.
119 • aes256<mode> - Same as aes128<mode>, except for a 256 bit key size.
121 • ecc - Elliptical Curve, defaults to ecc256.
123 • ecc192 - 192 bit ECC
125 • ecc224 - 224 bit ECC
127 • ecc256 - 256 bit ECC
129 • ecc384 - 384 bit ECC
131 • ecc521 - 521 bit ECC
133 • rsa - Default RSA: rsa2048
135 • rsa1024 - RSA with 1024 bit keysize.
137 • rsa2048 - RSA with 2048 bit keysize.
139 • rsa4096 - RSA with 4096 bit keysize.
141 Scheme Specifiers
143 Next, is an optional field, it can be skipped.
144 Schemes are usually Signing Schemes or Asymmetric Encryption Schemes.
146 Most signing schemes take a hash algorithm directly following the sign‐
147 ing scheme. If the hash algorithm is missing, it defaults to sha256.
148 Some take no arguments, and some take multiple arguments.
149 Hash Optional Scheme Specifiers
151 These scheme specifiers are followed by a dash and a valid hash algo‐
152 rithm, For example: oaep-sha256.
153 • oaep
155 • ecdh
157 • rsassa
159 • rsapss
161 • ecdsa
163 • ecschnorr
165 Multiple Option Scheme Specifiers
167 This scheme specifier is followed by a count (max size UINT16) then
168 followed by a dash(-) and a valid hash algorithm. * ecdaa For example,
169 ecdaa4-sha256. If no count is specified, it defaults to 4.
170 No Option Scheme Specifiers
172 This scheme specifier takes NO arguments. * rsaes
173 Symmetric Details Specifiers
175 This field is optional, and defaults based on the type of object being
176 created and it’s attributes. Generally, any valid Symmetric specifier
177 from the Type Specifiers list should work. If not specified, an asym‐
178 metric objects symmetric details defaults to aes128cfb.
179 Examples
181 Create an rsa2048 key with an rsaes asymmetric encryption scheme
182 tpm2_create -C parent.ctx -G rsa2048:rsaes -u key.pub -r key.priv
183 Create an ecc256 key with an ecdaa signing scheme with a count of 4 and
185 sha384 hash
186 /tpm2_create -C parent.ctx -G ecc256:ecdaa4-sha384 -u key.pub -r
187 key.priv cryptographic algorithms ALGORITHM.
188
190 This collection of options are common to many programs and provide in‐
191 formation that many users may expect.
192 • -h, --help=[man|no-man]: Display the tools manpage. By default, it
194 attempts to invoke the manpager for the tool, however, on failure
195 will output a short tool summary. This is the same behavior if the
196 “man” option argument is specified, however if explicit “man” is re‐
197 quested, the tool will provide errors from man on stderr. If the
198 “no-man” option if specified, or the manpager fails, the short op‐
199 tions will be output to stdout.
200 To successfully use the manpages feature requires the manpages to be
202 installed or on MANPATH, See man(1) for more details.
203 • -v, --version: Display version information for this tool, supported
205 tctis and exit.
206 • -V, --verbose: Increase the information that the tool prints to the
208 console during its execution. When using this option the file and
209 line number are printed.
210 • -Q, --quiet: Silence normal tool output to stdout.
212 • -Z, --enable-errata: Enable the application of errata fixups. Useful
214 if an errata fixup needs to be applied to commands sent to the TPM.
215 Defining the environment TPM2TOOLS_ENABLE_ERRATA is equivalent. in‐
216 formation many users may expect.
217
219 The TCTI or “Transmission Interface” is the communication mechanism
220 with the TPM. TCTIs can be changed for communication with TPMs across
221 different mediums.
222 To control the TCTI, the tools respect:
224 1. The command line option -T or --tcti
226 2. The environment variable: TPM2TOOLS_TCTI.
228 Note: The command line option always overrides the environment vari‐
230 able.
231 The current known TCTIs are:
233 • tabrmd - The resource manager, called tabrmd
235 (https://github.com/tpm2-software/tpm2-abrmd). Note that tabrmd and
236 abrmd as a tcti name are synonymous.
237 • mssim - Typically used for communicating to the TPM software simula‐
239 tor.
240 • device - Used when talking directly to a TPM device file.
242 • none - Do not initalize a connection with the TPM. Some tools allow
244 for off-tpm options and thus support not using a TCTI. Tools that do
245 not support it will error when attempted to be used without a TCTI
246 connection. Does not support ANY options and MUST BE presented as
247 the exact text of “none”.
248 The arguments to either the command line option or the environment
250 variable are in the form:
251 <tcti-name>:<tcti-option-config>
253 Specifying an empty string for either the <tcti-name> or <tcti-op‐
255 tion-config> results in the default being used for that portion respec‐
256 tively.
257 TCTI Defaults
259 When a TCTI is not specified, the default TCTI is searched for using
260 dlopen(3) semantics. The tools will search for tabrmd, device and
261 mssim TCTIs IN THAT ORDER and USE THE FIRST ONE FOUND. You can query
262 what TCTI will be chosen as the default by using the -v option to print
263 the version information. The “default-tcti” key-value pair will indi‐
264 cate which of the aforementioned TCTIs is the default.
265 Custom TCTIs
267 Any TCTI that implements the dynamic TCTI interface can be loaded. The
268 tools internally use dlopen(3), and the raw tcti-name value is used for
269 the lookup. Thus, this could be a path to the shared library, or a li‐
270 brary name as understood by dlopen(3) semantics.
271
273 This collection of options are used to configure the various known TCTI
274 modules available:
275 • device: For the device TCTI, the TPM character device file for use by
277 the device TCTI can be specified. The default is /dev/tpm0.
278 Example: -T device:/dev/tpm0 or export TPM2TOOLS_TCTI=“de‐
280 vice:/dev/tpm0”
281 • mssim: For the mssim TCTI, the domain name or IP address and port
283 number used by the simulator can be specified. The default are
284 127.0.0.1 and 2321.
285 Example: -T mssim:host=localhost,port=2321 or export TPM2TOOLS_TC‐
287 TI=“mssim:host=localhost,port=2321”
288 • abrmd: For the abrmd TCTI, the configuration string format is a se‐
290 ries of simple key value pairs separated by a `,' character. Each
291 key and value string are separated by a `=' character.
292 • TCTI abrmd supports two keys:
294 1. `bus_name' : The name of the tabrmd service on the bus (a
296 string).
297 2. `bus_type' : The type of the dbus instance (a string) limited to
299 `session' and `system'.
300 Specify the tabrmd tcti name and a config string of bus_name=com.ex‐
302 ample.FooBar:
303 \--tcti=tabrmd:bus_name=com.example.FooBar
305 Specify the default (abrmd) tcti and a config string of bus_type=ses‐
307 sion:
308 \--tcti:bus_type=session
310 NOTE: abrmd and tabrmd are synonymous. the various known TCTI mod‐
312 ules.
313
315 tpm2_geteccparameters ecc256 -o ecc.params
316
318 Tools can return any of the following codes:
319 • 0 - Success.
321 • 1 - General non-specific error.
323 • 2 - Options handling error.
325 • 3 - Authentication error.
327 • 4 - TCTI related error.
329 • 5 - Non supported scheme. Applicable to tpm2_testparams.
331
333 Github Issues (https://github.com/tpm2-software/tpm2-tools/issues)
334
336 See the Mailing List (https://lists.01.org/mailman/listinfo/tpm2)
337tpm2-tools tpm2_geteccparameters(1)