tpm2_nvreadpublic man page

tpm2_nvreadpublic(1) ā€” Display all defined Non-Volatile (NV)s indices.

Synopsis

tpm2_nvreadpublic [Options]

Description

tpm2_nvreadpublic(1) - Display all defined Non-Volatile (NV)s indices to stdout in a YAML format.

Display metadata for all defined NV indices. Metadata includes:

Example Output

``` 0x1500015: hash algorithm: friendly: sha256 value: 0xB attributes: friendly: ownerwrite|ownerread value: 0x2000200 size: 32 authorization policy:

0x1500017: hash algorithm: friendly: sha256 value: 0xB attributes: friendly: ownerwrite|ownerread value: 0x2000200 size: 32 authorization policy: ```

Options

This tool takes no tool specific options.

Common Options

This collection of options are common to many programs and provide information that many users may expect.

TCTI Configuration

The TCTI or "Transmission Interface" is the communication mechanism with the TPM. TCTIs can be changed for communication with TPMs across different mediums.

To control the TCTI, the tools respect:

  1. The command line option -T or --tcti
  2. The environment variable: TPM2TOOLS_TCTI.

Note: The command line option always overrides the environment variable.

The current known TCTIs are:

The arguments to either the command line option or the environment variable are in the form:

<tcti-name>:<tcti-option-config>

Specifying an empty string for either the <tcti-name> or <tcti-option-config> results in the default being used for that portion respectively.

TCTI Defaults

When a TCTI is not specified, the default TCTI is searched for using dlopen(3) semantics. The tools will search for tabrmd, device and mssim TCTIs IN THAT ORDER and USE THE FIRST ONE FOUND. You can query what TCTI will be chosen as the default by using the -v option to print the version information. The "default-tcti" key-value pair will indicate which of the aforementioned TCTIs is the default.

Custom TCTIs

Any TCTI that implements the dynamic TCTI interface can be loaded. The tools internally use dlopen(3), and the raw tcti-name value is used for the lookup. Thus, this could be a path to the shared library, or a library name as understood by dlopen(3) semantics.

Tcti Options

This collection of options are used to configure the various known TCTI modules available:

NV Attributes

NV Attributes are used to control various properties of the NV defined space. When specified as an option, either the raw bitfield mask or "nice-names" may be used. The values can be found in Table 204 Part 2 of the TPM2.0 specification, which can be found here:

<https://trustedcomputinggroup.org/wp-content/uploads/TPM-Rev-2.0-Part-2-Structures-01.38.pdf>

Nice names are calculated by taking the name field of table 204 and removing the prefix TPMA_NV_ and lowercasing the result. Thus, TPMA_NV_PPWRITE becomes ppwrite. Nice names can be joined using the bitwise or "|" symbol.

Note that the TPM_NT field is 4 bits wide, and thus can be set via nt= format. For instance, to set The fields TPMA_NV_OWNERREAD, TPMA_NV_OWNERWRITE, TPMA_NV_POLICYWRITE, and TPMA_NT = 0x2, the argument would be:

ownerread|ownerwrite|policywrite|nt=0x2

Additionally, the NT field, which denotes the type of the NV index, can also be specified via friendly names: * ordinary - Ordinary contains data that is opaque to the TPM that can only be modified using TPM2_NV_Write. * counter - Counter contains an 8-octet value that is to be used as a counter and can only be modified with TPM2_NV_Increment * bits - Bit Field contains an 8-octet value to be used as a bit field and can only be modified with TPM2_NV_SetBits. * pinfail - PIN Fail contains an 8-octet pinCount that increments on a PIN authorization failure and a pinLimit. * pinpass - PIN Pass contains an 8-octet pinCount that increments on a PIN authorization success and a pinLimit.

For instance, to set The fields TPMA_NV_OWNERREAD, TPMA_NV_OWNERWRITE, TPMA_NV_POLICYWRITE, and TPMA_NT = bits, the argument would be:

ownerread|ownerwrite|policywrite|nt=bits

Examples

List the defined NV indices to stdout

tpm2_nvreadpublic

Returns

Tools can return any of the following codes:

Bugs

Github Issues (https://github.com/tpm2-software/tpm2-tools/issues)

Help

See the Mailing List (https://lists.01.org/mailman/listinfo/tpm2)

Info

tpm2-tools General Commands Manual