---
name: "tpm2_nvrelease"
section: "1"
platform: "linux"
package: "tpm2-tools"
version: "3.1.3-2"
release: "Debian 10 (Buster)"
platforms: ["linux"]
url: "https://new.carta.tech/tpm2_nvrelease"
---

# tpm2\_nvrelease(1)

Release a Non-Volatile (NV) index.

## NAME

[**tpm2\_nvrelease**(1)](/tpm2_nvrelease/1.md) - Release a Non-Volatile (NV) index.

## SYNOPSIS

**tpm2\_nvrelease** \[*OPTIONS*\]

## DESCRIPTION

[**tpm2\_nvrelease**(1)](/tpm2_nvrelease/1.md) - Release a Non-Volatile (NV) index that was previously defined with [tpm2\_nvdefine(1)](/tpm2_nvdefine/1.md).

## OPTIONS

- •

  **-x**, **–index**=*NV\_INDEX*: Specifies the index to release.

- •

  **-a**, **–auth-handle**=*SECRET\_DATA\_FILE*: specifies the handle used to authorize:

  - •

    **0x40000001** for **TPM\_RH\_OWNER**

  - •

    **0x4000000C** for **TPM\_RH\_PLATFORM**

- •

  **-s**, **–size**=*SIZE*: specifies the size of data area in bytes.

- •

  **-P**, **–handle-passwd**=*HANDLE\_PASSWORD*: specifies the password of authHandle. Passwords should follow the “password formatting standards, see section”Password Formatting“.

- •

  **-S**, **–input-session-handle**=*SIZE*: Optional Input session handle from a policy session for authorization.

## COMMON OPTIONS

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

- •

  **-h**, **–help**: Display the tools manpage. This requires the manpages to be installed or on *MANPATH*, See [man(1)](/man/1.md) for more details.

- •

  **-v**, **–version**: Display version information for this tool, supported tctis and exit.

- •

  **-V**, **–verbose**: Increase the information that the tool prints to the console during its execution. When using this option the file and line number are printed.

- •

  **-Q**, **–quiet**: Silence normal tool output to stdout.

- •

  **-Z**, **–enable-errata**: Enable the application of errata fixups. Useful if an errata fixup needs to be applied to commands sent to the TPM. # TCTI ENVIRONMENT

This collection of environment variables that may be used to configure the various TCTI modules available.

The values passed through these variables can be overridden on a per-command basis using the available command line options, see the *TCTI\_OPTIONS* section.

The variables respected depend on how the software was configured.

- •

  *TPM2TOOLS\_TCTI\_NAME*: Select the TCTI used for communication with the next component down the TSS stack. In most configurations this will be the TPM but it could be a simulator or proxy. The current known TCTIs are:

  - •

    tabrmd - The new resource manager, called tabrmd (https://github.com/01org/tpm2-abrmd).

  - •

    socket - Typically used with the old resource manager, or talking directly to a simulator.

  - •

    device - Used when talking directly to a TPM device file.

- •

  *TPM2TOOLS\_DEVICE\_FILE*: When using the device TCTI, specify the TPM device file. The default is “/dev/tpm0”.

  Note: Using the tpm directly requires the users to ensure that concurrent access does not occur and that they manage the tpm resources. These tasks are usually managed by a resource manager. Linux 4.12 and greater supports an in kernel resource manager at “/dev/tpmrm”, typically “/dev/tpmrm0”.

- •

  *TPM2TOOLS\_SOCKET\_ADDRESS*: When using the socket TCTI, specify the domain name or IP address used. The default is 127.0.0.1.

- •

  *TPM2TOOLS\_SOCKET\_PORT*: When using the socket TCTI, specify the port number used. The default is 2321.

## TCTI OPTIONS

This collection of options are used to configure the varous TCTI modules available. They override any environment variables.

- •

  **-T**, **–tcti**=*TCTI\_NAME***\[**:*TCTI\_OPTIONS***\]**: Select the TCTI used for communication with the next component down the TSS stack. In most configurations this will be the resource manager: tabrmd (https://github.com/01org/tpm2-abrmd) Optionally, tcti specific options can appended to *TCTI\_NAME* by appending a **:** to *TCTI\_NAME*.

  - •

    For the device TCTI, the TPM device file for use by the device TCTI can be specified. The default is /dev/tpm0. Example: **-T device:/dev/tpm0**

  - •

    For the socket TCTI, the domain name or IP address and port number used by the socket can be specified. The default are 127.0.0.1 and 2321. Example: **-T socket:127.0.0.1:2321**

  - •

    For the abrmd TCTI, it takes no options. Example: **-T abrmd**

## Password Formatting

Passwords are interpreted in two forms, string and hex-string. A string password is not interpreted, and is directly used for authorization. A hex-string, is converted from a hexidecimal form into a byte array form, thus allowing passwords with non-printable and/or terminal un-friendly characters.

By default passwords are assumed to be in the string form. Password form is specified with special prefix values, they are:

- •

  str: - Used to indicate it is a raw string. Useful for escaping a password that starts with the “hex:” prefix.

- •

  hex: - Used when specifying a password in hex string format.

## EXAMPLES

-

  ```
  tpm2_nvrelease -x 0x1500016 -a 0x40000001 -P passwd
  ```

## RETURNS

0 on success or 1 on failure.

## BUGS

Github Issues (https://github.com/01org/tpm2-tools/issues)

## HELP

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