1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
|
% tpm2_stirrandom(1) tpm2-tools | General Commands Manual
# NAME
**tpm2_stirrandom**(1) - Add "additional information" into TPM RNG state.
# SYNOPSIS
**tpm2_stirrandom** [*OPTIONS*] [*ARGUMENT*]
# DESCRIPTION
**tpm2_stirrandom**(1) - Inject "additional information" as bytes into TPM entropy Protected Capability pool.
"Additional information" can be extracted from file specified as argument or
being read from *STDIN* if argument is not specified.
Up to 128 bytes can be injected at once through standard input to **tpm2_stirrandom**(1).
If input file is larger than 128 bytes, **tpm2_stirrandom**(1) will fail.
Adding data through **tpm2_stirrandom**(1) will trigger a reseeding of TPM
DRBG Protected Capability. It is used when performing any sensitive action
on a shielded location such as loading a persistent key or acting on a
Protected Capability like updating TPM firmware.
# OPTIONS
This command has no option
## References
[common options](common/options.md) collection of common options that provide
information many users may expect.
[common tcti options](common/tcti.md) collection of options used to configure
the various known TCTI modules.)
# EXAMPLES
## Inject from stdin using echo
```bash
echo -n "myrandomdata" | tpm2_stirrandom
```
## Inject 64 bytes from stdin using a file
```bash
dd if=/dev/urandom bs=1 count=64 > myrandom.bin
tpm2_stirrandom < ./myrandom.bin
```
## Inject bytes from a file and reading up to 128 bytes
```bash
dd if=/dev/urandom of=./myrandom.bin bs=1 count=42
tpm2_stirrandom ./myrandom.bin
```
# NOTES
Please be aware that even if the "additional information" added
by **tpm2_stirrandom**(1) can be entropy gathered from other DRBG
sources, the TPM has no way of determining if the value has any entropy or not.
As a consequence, it will just be considered as "additional input".
The "additional input" is as defined in [NIST SP800-90A](
https://nvlpubs.nist.gov/nistpubs/Legacy/SP/nistspecialpublication800-90.pdf)
[returns](common/returns.md)
[footer](common/footer.md)
|