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
185 and sha384 hash
186 /tpm2_create -C parent.ctx -G ecc256:ec‐
188 daa4-sha384 -u key.pub -r key.priv cryptographic algorithms ALGORITHM.
189
191 This collection of options are common to many programs and provide in‐
192 formation that many users may expect.
193 • -h, --help=[man|no-man]: Display the tools manpage. By default, it
195 attempts to invoke the manpager for the tool, however, on failure
196 will output a short tool summary. This is the same behavior if the
197 "man" option argument is specified, however if explicit "man" is re‐
198 quested, the tool will provide errors from man on stderr. If the
199 "no-man" option if specified, or the manpager fails, the short op‐
200 tions will be output to stdout.
201 To successfully use the manpages feature requires the manpages to be
203 installed or on MANPATH, See man(1) for more details.
204 • -v, --version: Display version information for this tool, supported
206 tctis and exit.
207 • -V, --verbose: Increase the information that the tool prints to the
209 console during its execution. When using this option the file and
210 line number are printed.
211 • -Q, --quiet: Silence normal tool output to stdout.
213 • -Z, --enable-errata: Enable the application of errata fixups. Useful
215 if an errata fixup needs to be applied to commands sent to the TPM.
216 Defining the environment TPM2TOOLS_ENABLE_ERRATA is equivalent. in‐
217 formation many users may expect.
218
220 The TCTI or "Transmission Interface" is the communication mechanism
221 with the TPM. TCTIs can be changed for communication with TPMs across
222 different mediums.
223 To control the TCTI, the tools respect:
225 1. The command line option -T or --tcti
227 2. The environment variable: TPM2TOOLS_TCTI.
229 Note: The command line option always overrides the environment vari‐
231 able.
232 The current known TCTIs are:
234 • tabrmd - The resource manager, called tabrmd
236 (https://github.com/tpm2-software/tpm2-abrmd). Note that tabrmd and
237 abrmd as a tcti name are synonymous.
238 • mssim - Typically used for communicating to the TPM software simula‐
240 tor.
241 • device - Used when talking directly to a TPM device file.
243 • none - Do not initalize a connection with the TPM. Some tools allow
245 for off-tpm options and thus support not using a TCTI. Tools that do
246 not support it will error when attempted to be used without a TCTI
247 connection. Does not support ANY options and MUST BE presented as
248 the exact text of "none".
249 The arguments to either the command line option or the environment
251 variable are in the form:
252 <tcti-name>:<tcti-option-config>
254 Specifying an empty string for either the <tcti-name> or <tcti-op‐
256 tion-config> results in the default being used for that portion respec‐
257 tively.
258 TCTI Defaults
260 When a TCTI is not specified, the default TCTI is searched for using
261 dlopen(3) semantics. The tools will search for tabrmd, device and
262 mssim TCTIs IN THAT ORDER and USE THE FIRST ONE FOUND. You can query
263 what TCTI will be chosen as the default by using the -v option to print
264 the version information. The "default-tcti" key-value pair will indi‐
265 cate which of the aforementioned TCTIs is the default.
266 Custom TCTIs
268 Any TCTI that implements the dynamic TCTI interface can be loaded. The
269 tools internally use dlopen(3), and the raw tcti-name value is used for
270 the lookup. Thus, this could be a path to the shared library, or a li‐
271 brary name as understood by dlopen(3) semantics.
272
274 This collection of options are used to configure the various known TCTI
275 modules available:
276 • device: For the device TCTI, the TPM character device file for use by
278 the device TCTI can be specified. The default is /dev/tpm0.
279 Example: -T device:/dev/tpm0 or export TPM2TOOLS_TCTI="de‐
281 vice:/dev/tpm0"
282 • mssim: For the mssim TCTI, the domain name or IP address and port
284 number used by the simulator can be specified. The default are
285 127.0.0.1 and 2321.
286 Example: -T mssim:host=localhost,port=2321 or export TPM2TOOLS_TC‐
288 TI="mssim:host=localhost,port=2321"
289 • abrmd: For the abrmd TCTI, the configuration string format is a se‐
291 ries of simple key value pairs separated by a ',' character. Each
292 key and value string are separated by a '=' character.
293 • TCTI abrmd supports two keys:
295 1. 'bus_name' : The name of the tabrmd service on the bus (a
297 string).
298 2. 'bus_type' : The type of the dbus instance (a string) limited to
300 'session' and 'system'.
301 Specify the tabrmd tcti name and a config string of bus_name=com.ex‐
303 ample.FooBar:
304 \--tcti=tabrmd:bus_name=com.example.FooBar
306 Specify the default (abrmd) tcti and a config string of bus_type=ses‐
308 sion:
309 \--tcti:bus_type=session
311 NOTE: abrmd and tabrmd are synonymous. the various known TCTI mod‐
313 ules.
314
316 tpm2_geteccparameters ecc256 -o ecc.params
317
319 Tools can return any of the following codes:
320 • 0 - Success.
322 • 1 - General non-specific error.
324 • 2 - Options handling error.
326 • 3 - Authentication error.
328 • 4 - TCTI related error.
330 • 5 - Non supported scheme. Applicable to tpm2_testparams.
332
334 Github Issues (https://github.com/tpm2-software/tpm2-tools/issues)
335
337 See the Mailing List (https://lists.01.org/mailman/listinfo/tpm2)
338tpm2-tools tpm2_geteccparameters(1)