Hi,
I am having a trivial doubt. Please see the below pipeline code sequence.
command1 | (command 2; commend 3)
I am aware that the command that follows pipe will run in the sub shell by the Unix kernel. But how about here? Since these set of commands are grouped under "parantheses", will... (6 Replies)
I have a cron on a Linux server that isn't executing properly.
CRON (with specific info replaced):
MAILTO=emailaddress@server.com
*/2 * * * * python /data/site/cron.py
OUTPUT:
python: can't open file '/data/site/cron.py
': No such file or directoryAdditional info
- The python path is... (3 Replies)
Hi Guys,
Just a question about subprocesses.. Lately one of our servers has started to throw out the following error:
SYSTEM ERROR: Too many subprocesses, cannot fork. Errno=12
We've already increased the threshold twice. Its now up to 8000 and the swap space has also been increased. We... (6 Replies)
Hi,
I am trying to run a shell script using subprocess in python.
I can run simple script with arguments using subprocess.But I am not able to embed xterm in subrocess command.
#!/usr/bin/python
import subprocess
subprocess.call()
Above code gives me error.
Please help me in... (2 Replies)
Hi guys,
I'm learning python and perl and i was trying to run from python a perl script using the subprocess module.
I have an issue that i don't understand regarding this.
I run this code:
#!/usr/bin/python
import subprocess
p2 = subprocess.Popen(,stdout=subprocess.PIPE)
output2 =... (2 Replies)
Greetings!
I set up a basic threading specimen which does the job:#!/usr/bin/python
import threading
class a(threading.Thread):
def __init__(self):
threading.Thread.__init__(self)
def run(self):
print("thread a finished")
class b(threading.Thread):
... (0 Replies)
Hi Experts,
Good morning.
I am trying to convert my hello.py to hello .exe file.
I followed the steps as mentioned in the documentation but getting errors in the end. Please help.
What I did as below--
Created hello.py file
print ("Hello world!")
raw_input('')
Then... (0 Replies)
I have a string like below
Note: I have have a single to any number of comma "," seperated string assigned to jdbc_trgt variable.
I need to split jdbc_trgt using comma(,) as the delimiter.
I tried the below but it fails as i dont know how can i read each split string iterately.
for... (4 Replies)
Discussion started by: mohtashims
4 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)