1tpm2_encryptdecrypt(1) General Commands Manual tpm2_encryptdecrypt(1)
2
6 tpm2_encryptdecrypt(1) - Performs symmetric encryption or decryption.
7
9 tpm2_encryptdecrypt [OPTIONS] [ARGUMENT]
10
12 tpm2_encryptdecrypt(1) - Performs symmetric encryption or decryption
13 with a specified symmetric key on the contents of FILE. If FILE is not
14 specified, defaults to stdin.
15
17 • -c, --key-context=OBJECT:
18 The encryption key object.
20 • -p, --auth=AUTH:
22 The authorization value for the encryption key object.
24 • -d, --decrypt:
26 Perform a decrypt operation. Defaults to encryption when this option
28 is not specified.
29 • -e, --pad:
31 Enable pkcs7 padding for applicable AES encryption modes cfb/cbc/ecb.
33 Applicable only to encryption and for input data with last block
34 shorter than encryption block length.
35 • -o, --output=FILE or STDOUT:
37 The output file path for either the encrypted or decrypted data. If
39 not specified, defaults to stdout.
40 • -G, --mode=ALGORITHM:
42 The key algorithm associated with this object. Defaults to object
44 properties or CFB if not defined.
45 • -t, --iv=FILE:
47 Optional initialization vector to use. Defaults to 0’s. Syntax al‐
49 lows for an input file and output file source to be specified. The
50 input file path is first, optionally followed by a colon “:” and the
51 output iv path. This output iv can be saved for subsequent calls
52 when chaining.
53 • --cphash=FILE
55 File path to record the hash of the command parameters. This is com‐
57 monly termed as cpHash. NOTE: When this option is selected, The tool
58 will not actually execute the command, it simply returns a cpHash.
59 • ARGUMENT the command line argument specifies the input file path FILE
61 of the data to encrypt or decrypt.
62 References
65 The type of a context object, whether it is a handle or file name, is
66 determined according to the following logic in-order:
67 • If the argument is a file path, then the file is loaded as a restored
69 TPM transient object.
70 • If the argument is a prefix match on one of:
72 • owner: the owner hierarchy
74 • platform: the platform hierarchy
76 • endorsement: the endorsement hierarchy
78 • lockout: the lockout control persistent object
80 • If the argument argument can be loaded as a number it will be treat
82 as a handle, e.g. 0x81010013 and used directly._OBJECT_.
83
85 Authorization for use of an object in TPM2.0 can come in 3 different
86 forms: 1. Password 2. HMAC 3. Sessions
87 NOTE: “Authorizations default to the EMPTY PASSWORD when not speci‐
89 fied”.
90 Passwords
92 Passwords are interpreted in the following forms below using prefix
93 identifiers.
94 Note: By default passwords are assumed to be in the string form when
96 they do not have a prefix.
97 String
99 A string password, specified by prefix “str:” or it’s absence (raw
100 string without prefix) is not interpreted, and is directly used for au‐
101 thorization.
102 Examples
104 foobar
105 str:foobar
106 Hex-string
108 A hex-string password, specified by prefix “hex:” is converted from a
109 hexidecimal form into a byte array form, thus allowing passwords with
110 non-printable and/or terminal un-friendly characters.
111 Example
113 hex:1122334455667788
114 File
116 A file based password, specified be prefix “file:” should be the path
117 of a file containing the password to be read by the tool or a “-” to
118 use stdin. Storing passwords in files prevents information leakage,
119 passwords passed as options can be read from the process list or common
120 shell history features.
121 Examples
123 # to use stdin and be prompted
124 file:-
125 # to use a file from a path
127 file:path/to/password/file
128 # to echo a password via stdin:
130 echo foobar | tpm2_tool -p file:-
131 # to use a bash here-string via stdin:
133 tpm2_tool -p file:- <<< foobar
135 Sessions
137 When using a policy session to authorize the use of an object, prefix
138 the option argument with the session keyword. Then indicate a path to
139 a session file that was created with tpm2_startauthsession(1). Option‐
140 ally, if the session requires an auth value to be sent with the session
141 handle (eg policy password), then append a + and a string as described
142 in the Passwords section.
143 Examples
145 To use a session context file called session.ctx.
146 session:session.ctx
148 To use a session context file called session.ctx AND send the authvalue
150 mypassword.
151 session:session.ctx+mypassword
153 To use a session context file called session.ctx AND send the HEX auth‐
155 value 0x11223344.
156 session:session.ctx+hex:11223344
158 PCR Authorizations
160 You can satisfy a PCR policy using the “pcr:” prefix and the PCR mini‐
161 language. The PCR minilanguage is as follows:
162 <pcr-spec>=<raw-pcr-file>
163 The PCR spec is documented in in the section “PCR bank specifiers”.
165 The raw-pcr-file is an optional argument that contains the output of
167 the raw PCR contents as returned by tpm2_pcrread(1).
168 PCR bank specifiers (pcr.md)
170 Examples
172 To satisfy a PCR policy of sha256 on banks 0, 1, 2 and 3 use a specifi‐
173 er of:
174 pcr:sha256:0,1,2,3
176 specifying AUTH.
178
180 Options that take algorithms support “nice-names”.
181 There are two major algorithm specification string classes, simple and
183 complex. Only certain algorithms will be accepted by the TPM, based on
184 usage and conditions.
185 Simple specifiers
187 These are strings with no additional specification data. When creating
188 objects, non-specified portions of an object are assumed to defaults.
189 You can find the list of known “Simple Specifiers” below.
190 Asymmetric
192 • rsa
193 • ecc
195 Symmetric
197 • aes
198 • camellia
200 • sm4
202 Hashing Algorithms
204 • sha1
205 • sha256
207 • sha384
209 • sha512
211 • sm3_256
213 • sha3_256
215 • sha3_384
217 • sha3_512
219 Keyed Hash
221 • hmac
222 • xor
224 Signing Schemes
226 • rsassa
227 • rsapss
229 • ecdsa
231 • ecdaa
233 • ecschnorr
235 • sm2
237 Asymmetric Encryption Schemes
239 • oaep
240 • rsaes
242 • ecdh
244 Modes
246 • ctr
247 • ofb
249 • cbc
251 • cfb
253 • ecb
255 Misc
257 • null
258 Complex Specifiers
260 Objects, when specified for creation by the TPM, have numerous algo‐
261 rithms to populate in the public data. Things like type, scheme and
262 asymmetric details, key size, etc. Below is the general format for
263 specifying this data: <type>:<scheme>:<symmetric-details>
264 Type Specifiers
266 This portion of the complex algorithm specifier is required. The re‐
267 maining scheme and symmetric details will default based on the type
268 specified and the type of the object being created.
269 • aes - Default AES: aes128
271 • aes128<mode> - 128 bit AES with optional mode (ctr|ofb|cbc|cfb|ecb).
273 If mode is not specified, defaults to null.
274 • aes192<mode> - Same as aes128<mode>, except for a 192 bit key size.
276 • aes256<mode> - Same as aes128<mode>, except for a 256 bit key size.
278 • sm4 - Default SM4: sm4128
280 • sm4128 or sm4_128 <mode> - 128 bit SM4 with optional mode
282 (ctr|ofb|cbc|cfb|ecb). If mode is not specified, defaults to null.
283 • ecc - Elliptical Curve, defaults to ecc256.
285 • ecc192 or ecc_nist_p192 - 192 bit ECC NIST curve
287 • ecc224 or ecc_nist_p224 - 224 bit ECC NIST curve
289 • ecc256 or ecc_nist_p256 - 256 bit ECC NIST curve
291 • ecc384 or ecc_nist_p384 - 384 bit ECC NIST curve
293 • ecc521 or ecc_nist_p521 - 521 bit ECC NIST curve
295 • ecc_sm2 or ecc_sm2_p256 - 256 bit SM2 curve
297 • rsa - Default RSA: rsa2048
299 • rsa1024 - RSA with 1024 bit keysize.
301 • rsa2048 - RSA with 2048 bit keysize.
303 • rsa3072 - RSA with 3072 bit keysize.
305 • rsa4096 - RSA with 4096 bit keysize.
307 Scheme Specifiers
309 Next, is an optional field, it can be skipped.
310 Schemes are usually Signing Schemes or Asymmetric Encryption Schemes.
312 Most signing schemes take a hash algorithm directly following the sign‐
313 ing scheme. If the hash algorithm is missing, it defaults to sha256.
314 Some take no arguments, and some take multiple arguments.
315 Hash Optional Scheme Specifiers
317 These scheme specifiers are followed by a dash and a valid hash algo‐
318 rithm, For example: oaep-sha256.
319 • oaep
321 • ecdh
323 • rsassa
325 • rsapss
327 • ecdsa
329 • ecschnorr
331 • sm2
333 Multiple Option Scheme Specifiers
335 This scheme specifier is followed by a count (max size UINT16) then
336 followed by a dash(-) and a valid hash algorithm. * ecdaa For example,
337 ecdaa4-sha256. If no count is specified, it defaults to 4.
338 No Option Scheme Specifiers
340 This scheme specifier takes NO arguments. * rsaes
341 Symmetric Details Specifiers
343 This field is optional, and defaults based on the type of object being
344 created and it’s attributes. Generally, any valid Symmetric specifier
345 from the Type Specifiers list should work. If not specified, an asym‐
346 metric objects symmetric details defaults to aes128cfb.
347 Examples
349 Create an rsa2048 key with an rsaes asymmetric encryption scheme
350 tpm2_create -C parent.ctx -G rsa2048:rsaes -u key.pub -r key.priv
351 Create an ecc256 key with an ecdaa signing scheme with a count of 4 and
353 sha384 hash
354 /tpm2_create -C parent.ctx -G ecc256:ecdaa4-sha384 -u key.pub -r
355 key.priv cryptographic algorithms ALGORITHM.
356
358 This collection of options are common to many programs and provide in‐
359 formation that many users may expect.
360 • -h, --help=[man|no-man]: Display the tools manpage. By default, it
362 attempts to invoke the manpager for the tool, however, on failure
363 will output a short tool summary. This is the same behavior if the
364 “man” option argument is specified, however if explicit “man” is re‐
365 quested, the tool will provide errors from man on stderr. If the
366 “no-man” option if specified, or the manpager fails, the short op‐
367 tions will be output to stdout.
368 To successfully use the manpages feature requires the manpages to be
370 installed or on MANPATH, See man(1) for more details.
371 • -v, --version: Display version information for this tool, supported
373 tctis and exit.
374 • -V, --verbose: Increase the information that the tool prints to the
376 console during its execution. When using this option the file and
377 line number are printed.
378 • -Q, --quiet: Silence normal tool output to stdout.
380 • -Z, --enable-errata: Enable the application of errata fixups. Useful
382 if an errata fixup needs to be applied to commands sent to the TPM.
383 Defining the environment TPM2TOOLS_ENABLE_ERRATA is equivalent. in‐
384 formation many users may expect.
385
387 The TCTI or “Transmission Interface” is the communication mechanism
388 with the TPM. TCTIs can be changed for communication with TPMs across
389 different mediums.
390 To control the TCTI, the tools respect:
392 1. The command line option -T or --tcti
394 2. The environment variable: TPM2TOOLS_TCTI.
396 Note: The command line option always overrides the environment vari‐
398 able.
399 The current known TCTIs are:
401 • tabrmd - The resource manager, called tabrmd
403 (https://github.com/tpm2-software/tpm2-abrmd). Note that tabrmd and
404 abrmd as a tcti name are synonymous.
405 • mssim - Typically used for communicating to the TPM software simula‐
407 tor.
408 • device - Used when talking directly to a TPM device file.
410 • none - Do not initalize a connection with the TPM. Some tools allow
412 for off-tpm options and thus support not using a TCTI. Tools that do
413 not support it will error when attempted to be used without a TCTI
414 connection. Does not support ANY options and MUST BE presented as
415 the exact text of “none”.
416 The arguments to either the command line option or the environment
418 variable are in the form:
419 <tcti-name>:<tcti-option-config>
421 Specifying an empty string for either the <tcti-name> or <tcti-op‐
423 tion-config> results in the default being used for that portion respec‐
424 tively.
425 TCTI Defaults
427 When a TCTI is not specified, the default TCTI is searched for using
428 dlopen(3) semantics. The tools will search for tabrmd, device and
429 mssim TCTIs IN THAT ORDER and USE THE FIRST ONE FOUND. You can query
430 what TCTI will be chosen as the default by using the -v option to print
431 the version information. The “default-tcti” key-value pair will indi‐
432 cate which of the aforementioned TCTIs is the default.
433 Custom TCTIs
435 Any TCTI that implements the dynamic TCTI interface can be loaded. The
436 tools internally use dlopen(3), and the raw tcti-name value is used for
437 the lookup. Thus, this could be a path to the shared library, or a li‐
438 brary name as understood by dlopen(3) semantics.
439
441 This collection of options are used to configure the various known TCTI
442 modules available:
443 • device: For the device TCTI, the TPM character device file for use by
445 the device TCTI can be specified. The default is /dev/tpm0.
446 Example: -T device:/dev/tpm0 or export TPM2TOOLS_TCTI=“de‐
448 vice:/dev/tpm0”
449 • mssim: For the mssim TCTI, the domain name or IP address and port
451 number used by the simulator can be specified. The default are
452 127.0.0.1 and 2321.
453 Example: -T mssim:host=localhost,port=2321 or export TPM2TOOLS_TC‐
455 TI=“mssim:host=localhost,port=2321”
456 • abrmd: For the abrmd TCTI, the configuration string format is a se‐
458 ries of simple key value pairs separated by a `,' character. Each
459 key and value string are separated by a `=' character.
460 • TCTI abrmd supports two keys:
462 1. `bus_name' : The name of the tabrmd service on the bus (a
464 string).
465 2. `bus_type' : The type of the dbus instance (a string) limited to
467 `session' and `system'.
468 Specify the tabrmd tcti name and a config string of bus_name=com.ex‐
470 ample.FooBar:
471 \--tcti=tabrmd:bus_name=com.example.FooBar
473 Specify the default (abrmd) tcti and a config string of bus_type=ses‐
475 sion:
476 \--tcti:bus_type=session
478 NOTE: abrmd and tabrmd are synonymous. the various known TCTI mod‐
480 ules.
481
484 tpm2_createprimary -c primary.ctx
485 tpm2_create -C primary.ctx -Gaes128 -u key.pub -r key.priv
486 tpm2_load -C primary.ctx -u key.pub -r key.priv -c key.ctx
487
489 echo "my secret" > secret.dat
490 tpm2_encryptdecrypt -c key.ctx -o secret.enc secret.dat
491 tpm2_encryptdecrypt -d -c key.ctx -o secret.dec secret.enc
492 cat secret.dec
493 my secret
494
496 Tools can return any of the following codes:
497 • 0 - Success.
499 • 1 - General non-specific error.
501 • 2 - Options handling error.
503 • 3 - Authentication error.
505 • 4 - TCTI related error.
507 • 5 - Non supported scheme. Applicable to tpm2_testparams.
509
511 Github Issues (https://github.com/tpm2-software/tpm2-tools/issues)
512
514 See the Mailing List (https://lists.linuxfoundation.org/mailman/listin‐
515 fo/tpm2)
516tpm2-tools tpm2_encryptdecrypt(1)