1tpm2_nvread(1) General Commands Manual tpm2_nvread(1)
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6 tpm2_nvread(1) - Read the data stored in a Non-Volatile (NV)s index.
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9 tpm2_nvread [OPTIONS]
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12 tpm2_nvread(1) - Read the data stored in a Non-Volatile (NV)s index.
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15 · -x, –index=NV_INDEX: Specifies the index to define the space at.
16 · -a, –auth-handle=SECRET_DATA_FILE: specifies the handle used to au‐
18 thorize:
19 · 0x40000001 for TPM_RH_OWNER
21 · 0x4000000C for TPM_RH_PLATFORM
23 · -f, –output=FILE: file to write data
25 · -P, –handle-passwd=HANDLE_PASSWORD: specifies the password of auth‐
27 Handle. Passwords should follow the “password formatting standards,
28 see section”Password Formatting“.
29 · -s, –size=SIZE: Specifies the size of data to be read in bytes,
31 starting from 0 if offset is not specified. If not specified, the
32 size of the data as reported by the public portion of the index will
33 be used.
34 · -o, –offset=OFFSET: The offset within the NV index to start reading
36 from.
37 · -S, –input-session-handle=SIZE: Optional Input session handle from a
39 policy session for authorization.
40 · -L, –set-list==PCR_SELECTION_LIST:
42 The list of pcr banks and selected PCRs' ids. PCR_SELECTION_LIST
44 values should follow the pcr bank specifiers standards, see section
45 “PCR Bank Specfiers”.
46 · -F,**–pcr-input-file=PCR_INPUT_FILE
48 Optional Path or Name of the file containing expected pcr values for
50 the specified index. Default is to read the current PCRs per the set
51 list.
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54 This collection of options are common to many programs and provide in‐
55 formation that many users may expect.
56 · -h, –help: Display the tools manpage. This requires the manpages to
58 be installed or on MANPATH, See man(1) for more details.
59 · -v, –version: Display version information for this tool, supported
61 tctis and exit.
62 · -V, –verbose: Increase the information that the tool prints to the
64 console during its execution. When using this option the file and
65 line number are printed.
66 · -Q, –quiet: Silence normal tool output to stdout.
68 · -Z, –enable-errata: Enable the application of errata fixups. Useful
70 if an errata fixup needs to be applied to commands sent to the TPM.
71 # TCTI ENVIRONMENT
72 This collection of environment variables that may be used to configure
74 the various TCTI modules available.
75 The values passed through these variables can be overridden on a
77 per-command basis using the available command line options, see the TC‐
78 TI_OPTIONS section.
79 The variables respected depend on how the software was configured.
81 · TPM2TOOLS_TCTI_NAME: Select the TCTI used for communication with the
83 next component down the TSS stack. In most configurations this will
84 be the TPM but it could be a simulator or proxy. The current known
85 TCTIs are:
86 · tabrmd - The new resource manager, called tabrmd
88 (https://github.com/01org/tpm2-abrmd).
89 · socket - Typically used with the old resource manager, or talking
91 directly to a simulator.
92 · device - Used when talking directly to a TPM device file.
94 · TPM2TOOLS_DEVICE_FILE: When using the device TCTI, specify the TPM
96 device file. The default is “/dev/tpm0”.
97 Note: Using the tpm directly requires the users to ensure that con‐
99 current access does not occur and that they manage the tpm resources.
100 These tasks are usually managed by a resource manager. Linux 4.12
101 and greater supports an in kernel resource manager at “/dev/tpmrm”,
102 typically “/dev/tpmrm0”.
103 · TPM2TOOLS_SOCKET_ADDRESS: When using the socket TCTI, specify the do‐
105 main name or IP address used. The default is 127.0.0.1.
106 · TPM2TOOLS_SOCKET_PORT: When using the socket TCTI, specify the port
108 number used. The default is 2321.
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111 This collection of options are used to configure the varous TCTI mod‐
112 ules available. They override any environment variables.
113 · -T, –tcti=TCTI_NAME[:TCTI_OPTIONS]: Select the TCTI used for communi‐
115 cation with the next component down the TSS stack. In most configu‐
116 rations this will be the resource manager: tabrmd
117 (https://github.com/01org/tpm2-abrmd) Optionally, tcti specific op‐
118 tions can appended to TCTI_NAME by appending a : to TCTI_NAME.
119 · For the device TCTI, the TPM device file for use by the device TCTI
121 can be specified. The default is /dev/tpm0. Example: -T de‐
122 vice:/dev/tpm0
123 · For the socket TCTI, the domain name or IP address and port number
125 used by the socket can be specified. The default are 127.0.0.1 and
126 2321. Example: -T socket:127.0.0.1:2321
127 · For the abrmd TCTI, it takes no options. Example: -T abrmd
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131 Passwords are interpreted in two forms, string and hex-string. A
132 string password is not interpreted, and is directly used for authoriza‐
133 tion. A hex-string, is converted from a hexidecimal form into a byte
134 array form, thus allowing passwords with non-printable and/or terminal
135 un-friendly characters.
136 By default passwords are assumed to be in the string form. Password
138 form is specified with special prefix values, they are:
139 · str: - Used to indicate it is a raw string. Useful for escaping a
141 password that starts with the “hex:” prefix.
142 · hex: - Used when specifying a password in hex string format.
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146 To read 32 bytes from an index starting at offset 0:
147 tpm2_nvread -x 0x1500016 -a 0x40000001 -s 32
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151 0 on success or 1 on failure.
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154 Github Issues (https://github.com/01org/tpm2-tools/issues)
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157 See the Mailing List (https://lists.01.org/mailman/listinfo/tpm2)
158tpm2-tools SEPTEMBER 2017 tpm2_nvread(1)