Hi,
I'm writing a KSH script, and at one point, I have to call a new shell and perform some variable assignments.
I noticed that the assignment is not working.
Please see two samples below:
Command 1:
#>ksh "i=2;echo I is $i"
Output:
#>I is
Command 2:
#>ksh <<EOF
> i=2
> echo I... (7 Replies)
I have a very tough shell program to do. Here is the assignment:
Write a non-interactive script that takes in any number of directory names as arguments and calculates and outputs the total number of blocks of disk space occupied by the ordinary files in all the directories. For example, the... (0 Replies)
Doubt #1
I have a program that I want the user to input date. When the user inputs the date, is it able to format it to system date dd-mm-yyy and then echo the value into a text file?
Doubt#2
If the above is not going to work, I tried to have the system date appear in the user input field and... (6 Replies)
Hi guys,
I'm basically looking for some help with a bash script I've written. It's purpose is to assign process to individual CPU cores once that process hits 15% CPU usage or more. If it drops below 15%, it's unassigned again (using taskset).
My problem is that I can't think of a way to... (2 Replies)
Here's the assignment. I'll bold the parts that are rough for me. Unfortunately, that's quite a bit lol. The syntax is, of course, where my issues lie, for the most part. I don't have a lot of programming experience at all :/. I'd post what I've already done, but I'm so lost I really don't know... (1 Reply)
I am going to provide a chunks of codes that I do not understand. Please help with them in a layman's terms.
1) ${DEBUG:-0}
--------------------------------------------------------------------------
2) print "${1}"
... (7 Replies)
Suppose I have a file named Stuff in the same directory as my script. Does the following assign the file Stuff to a variable?
Var="Stuff"
Why doesn't this just assign the string Stuff? Or rather how would I assign the string Stuff to a variable in this situation?
Also, what exactly is... (3 Replies)
I have come across a weird behaviour in bash and would love to get to the bottom of it. If I execute echo -e "\na\nb\nc\n" at the command line, I get:
a
b
c
However, if I wrap it in an assignment such as:
A="$( echo -e "\na\nb\nc\n" )"then I get
a
b
cIt doesn't show very well,... (4 Replies)
I have a little code block (executing on AIX 7.1) that I cannot understand why the NOTFREE=0 does not appear to be assigned even though it goes through that block. This causes a unary operator issue.
#!/bin/bash
PLATFORM="AIX"
NEEDSPC=3000
set -x
if ; then
lsvg | grep -v rootvg | while... (6 Replies)
Discussion started by: port43
6 Replies
LEARN ABOUT CENTOS
tpm_quote_tools
TPM QUOTE TOOLS(8) TPM QUOTE TOOLS(8)NAME
TPM Quote Tools
PROGRAMS
tpm_mkuuid, tpm_mkaik, tpm_loadkey, tpm_unloadkey, tpm_getpcrhash, tpm_updatepcrhash, tpm_getquote, tpm_verifyquote
DESCRIPTION
TPM Quote Tools is a collection of programs that provide support for TPM based attestation using the TPM quote operation.
A TPM contains a set of Platform Configuration Registers (PCRs). In a well configured machine, some of these registers are set to known
values during the boot up process or at other times. For example, a PCR might contain the hash of a boot loader in memory before it is
run.
The TPM quote operation is used to authoritatively verify the contents of a TPM's Platform Configuration Registers (PCRs). During provi-
sioning, a composite hash of a selected set of PCRs is computed. The TPM quote operation produces a composite hash that can be compared
with the one computed while provisioning.
To use the TPM quote operation, keys must be generated. During provisioning, an Attestation Identity Key (AIK) is generated for each TPM,
and the public part of the key is made available to entities that validate quotes.
The TPM quote operation returns signed data and a signature. The data that is signed contains the PCRs selected for the operation, the
composite hash for the selected PCRs, and a nonce provided as input, and used to prevent replay attacks. At provisioning time, the data
that is signed is stored, not just the composite hash. The signature is discarded.
An entity that wishes to evaluate a machine generates a nonce, and sends it along with the set of PCR used to generate the composite PCR
hash at provisioning time. For this use of the TPM quote operation, the signed data is ignored, and the signature returned is used to val-
idate the state of the TPM's PCRs. Given the signature, the evaluating entity replaces the nonce in the signed data generated at provi-
sioning time, and checks to see if the signature is valid for the data. If so, this check ensures the selected PCRs contain values that
match the ones measured during provisioning.
A typical scenario for an enterprise using these tools follows. The tools expect AIKs to be referenced via one enterprise-wide Universally
Unique Identifier (UUID). The program tpm_mkuuid creates one.
For each machine being checked, an AIK is created using tpm_mkaik. The key blob produced is bound to the UUID on its machine using
tpm_loadkey. The public key associated with the AIK is sent to the entities that verify quotes. Finally, the expected PCR composite hash
is obtained using tpm_getpcrhash. When the expected PCR values change, a new hash can be generated with tpm_updatepcrhash.
The program to obtain a quote, and thus measure the current state of the PCRs is tpm_getquote. The program that verifies the quote
describes the same PCR composite hash as was measured initially is tpm_verifyquote.
SEE ALSO tpm_mkuuid(8), tpm_mkaik(8), tpm_loadkey(8), tpm_unloadkey(8), tpm_getpcrhash(8), tpm_updatepcrhash(8), tpm_getquote(8), tpm_verifyquote(8)
Oct 2010 TPM QUOTE TOOLS(8)