Now imagine if someone fed it `find /dev -type b -exec dd if=/dev/urandom of={}`.
I don't want my strings to be able to execute arbitrary code like this.
If you put that into the string variable and execute the line I posted, nothing will happen other than the tokens being placed into the positional parameters. The code in $string will not be executed.
How do you pass parameters over to another script and run the receiving script? .
Here is an example of what I am talking about.
for x in `cat Allx`
do
su myaccount -c "/temp/scripts/temp_script $x" > /dev/null 2>$1 $
done
I was expecting the tem_script to be... (1 Reply)
Hi:- I need to parse a script 3 parameters (file, subject and email address). This is what I currently have:
allargs=$*
argcount=`echo $allargs | awk -F: '{ print NF }' ` # Total Number of arguments
pdffile=`echo $allargs | awk -F: '{ print $1 }' ` # PDF/binary file to be encoded... (4 Replies)
Sceduled backups with vdump have been delayed as a mounted system had crashed while I was away for 2 weeks. Now there are 5 simultaneous vdumps running very slowly. The full system backup usually takes a whole weekend.
Can I safely kill these? (I will have to live without a backup untill next... (4 Replies)
I have a job script that runs with input parms from the command line.
job.sh -p parm1_parm2_parm3_parm4_file_1.dat
The parms are separated by _
The last parm is a file name and can have an _ in the name.
I currently use the following commands to extract the parms
parm1=`eval echo... (3 Replies)
Hi all,
Am writing a script that does a rm/mv if a file exist, however, in one scenario, one of the variables which is supposed to a variable for a directory is undefined/blank so instead of the variable resolving to /tmp/logfile.dmp, it resolves instead to / so the rm translates to a rm /... (2 Replies)
I get a strange problem here, and ask for help.
(gdb)
28 set_file_bit( file, bytePos, bitPos, argv );
(gdb) p argv
$3 = 0xbfffef5c "00"
(gdb) s
set_file_bit (file=0x804b008, bytePos=2, bitPos=2, binary=0x80490e5 "11") at util/file.c:112
... (2 Replies)
Greetings,
I need some help performing a system admin function that I have been tasked with. The request seems simple enough, but my feeling is that it might be more complicated than it seems.
Here is what i've been tasked with:
SunOS 5.10 Generic_142900-15 sun4u sparc SUNW,SPARC-Enterprise... (3 Replies)
I am using:
reboot -- cdrom
However I'm afraid of causing file system errors/corruption. I've seen many threads say that
init 6
is safer, but I need to get to CDROM.
Is there a command that is as safe as init, but can boot to cdrom, or should I not worry so much about the reboot... (5 Replies)
I wanted to know whether all files under /tmp can be safely removed. I guess that /tmp may also have temporary files for applications currently being worked on, so at the most those applications may just shut down.
I hope that my question is clear whether all files under /tmp can be safely... (5 Replies)
Discussion started by: RHCE
5 Replies
LEARN ABOUT OPENSOLARIS
urandom
random(7D) Devices random(7D)NAME
random, urandom - Strong random number generator device
SYNOPSIS
/dev/random
/dev/urandom
DESCRIPTION
The /dev/random and /dev/urandom files are special files that are a source for random bytes generated by the kernel random number generator
device. The /dev/random and /dev/urandom files are suitable for applications requiring high quality random numbers for cryptographic pur-
poses.
The generator device produces random numbers from data and devices available to the kernel and estimates the amount of randomness (or
"entropy") collected from these sources. The entropy level determines the amount of high quality random numbers that are produced at a
given time.
Applications retrieve random bytes by reading /dev/random or /dev/urandom. The /dev/random interface returns random bytes only when suffi-
cient amount of entropy has been collected. If there is no entropy to produce the requested number of bytes, /dev/random blocks until more
entropy can be obtained. Non-blocking I/O mode can be used to disable the blocking behavior. The /dev/random interface also supports
poll(2). Note that using poll(2) will not increase the speed at which random numbers can be read.
Bytes retrieved from /dev/random provide the highest quality random numbers produced by the generator, and can be used to generate long
term keys and other high value keying material.
The /dev/urandom interface returns bytes regardless of the amount of entropy available. It does not block on a read request due to lack of
entropy. While bytes produced by the /dev/urandom interface are of lower quality than bytes produced by /dev/random, they are nonetheless
suitable for less demanding and shorter term cryptographic uses such as short term session keys, paddings, and challenge strings.
Data can be written to /dev/random and /dev/urandom. Data written to either special file is added to the generator's internal state. Data
that is difficult to predict by other users may contribute randomness to the generator state and help improve the quality of future gener-
ated random numbers.
/dev/random collects entropy from providers that are registered with the kernel-level cryptographic framework and implement random number
generation routines. The cryptoadm(1M) utility allows an administrator to configure which providers will be used with /dev/random.
ERRORS
EAGAIN O_NDELAY or O_NONBLOCK was set and no random bytes are available for reading from /dev/random.
EINTR A signal was caught while reading and no data was transferred.
ENOXIO open(2) request failed on /dev/random because no entropy provider is available.
FILES
/dev/random
/dev/urandom
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Availability | SUNWcsr |
|Interface Stability |Evolving |
+-----------------------------+-----------------------------+
SEE ALSO cryptoadm(1M), open(2), poll(2), attributes(5)NOTES
/dev/random can be configured to use only the hardware-based providers registered with the kernel-level cryptographic framework by dis-
abling the software-based provider using cryptoadm(1M). You can also use cryptoadm(1M) to obtain the name of the software-based provider.
Because no entropy is available, disabling all randomness providers causes read(2) and poll(2) on /dev/random to block indefinitely and
results in a warning message being logged and displayed on the system console. However, read(2) and poll(2) on /dev/urandom continue to
work in this case.
An implementation of the /dev/random and /dev/urandom kernel-based random number generator first appeared in Linux 1.3.30.
A /dev/random interface for Solaris first appeared as part of the CryptoRand implementation.
SunOS 5.11 1 Sep 2008 random(7D)