Security is the degree of resistance to, or protection from, harm. It applies to any vulnerable and valuable asset, such as a person, dwelling, community, nation, or organization.
Identify a scam
How do I identify a scam message ?
The first 3 necessity for a person is food, shelter and clothing. But now internet is the 4th important necessity in people’s life. The usage of internet is widely used for seeking numbers to all kind of information. But the biggest disadvantage is that you might get caught by scam mails. The scam mailsare sent by the scam companies which are listed on the internet. Try avoiding this website which can be harmful for your computers. To avoid this kind of scam messages download a fee version of anti-scam software from the internet. These stop the scam mail to enter your inbox.
The scam companies can send you a message which has an interesting subject like how to avoid cancer? Or let say about earning money in 15 days. The most usual scams found are the Nigerian. These letters contains generally of transferring money. For example a person claimed to be a widower and asked to transfer money to your bank account. It is better if you don’t give them any personal information. You will never know when you will be bankrupt. These types of letters are otherwise known as 419 scams. How will you find out if the person is a scammer or not? Here are some points which will help you in identifying the scammer.
– Scammer never uses his original name or any other personal identification.
– They always write in capital letter and write to you in formal method like referring you with Mr. or miss in each letter.
– There are always a friendless words like my dear or greeting to you in the letter.
– The body of the letter is mostly filled with financial term like lottery, funds etc.
– You can identify the scammer from their e-mail address.
– They register the e-mail address in a formal name for example email@example.com. This shows that they are fake address.
Some of the popular messages are listed below :
Gain lot of money by working from your place. There is no such company who allows you to work from your place. Another type of message is you have won a price from so and so company which you have never heard of. It is highly dangerous if you give your account data to a stranger. Never trust an unknown person who might offer you a job with higher salary. There are many companies who literally steal the money from you via internet. It is safer if you don’t open an unknown scam messages. There is a possibility of hacking your computer through these scam messages. So to stay on a safer side you can download free trial or buy the original anti-scam software which can block all the scam messages.
xinetd – the extended Internet services daemon
xinetd performs the same function as inetd: it starts programs that
provide Internet services. Instead of having such servers started at
system initialization time, and be dormant until a connection request
arrives, xinetd is the only daemon process started and it listens on
all service ports for the services listed in its configuration file.
When a request comes in, xinetd starts the appropriate server. Because
of the way it operates, xinetd (as well as inetd) is also referred to
as a super-server.
The services listed in xinetd’s configuration file can be separated
into two groups. Services in the first group are called multi-threaded
and they require the forking of a new server process for each new con-
nection request. The new server then handles that connection. For
such services, xinetd keeps listening for new requests so that it can
spawn new servers. On the other hand, the second group includes ser-
vices for which the service daemon is responsible for handling all new
connection requests. Such services are called single-threaded and
xinetd will stop handling new requests for them until the server dies.
Services in this group are usually datagram-based.
So far, the only reason for the existence of a super-server was to con-
serve system resources by avoiding to fork a lot of processes which
might be dormant for most of their lifetime. While fulfilling this
function, xinetd takes advantage of the idea of a super-server to pro-
vide features such as access control and logging. Furthermore, xinetd
is not limited to services listed in /etc/services. Therefore, anybody
can use xinetd to start special-purpose servers.
-d Enables debug mode. This produces a lot of debugging output, and
it makes it possible to use a debugger on xinetd.
This option enables syslog logging of xinetd-produced messages
using the specified syslog facility. The following facility
names are supported: daemon, auth, user, local[0-7] (check sys-
log.conf(5) for their meanings). This option is ineffective in
debug mode since all relevant messages are sent to the terminal.
xinetd-produced messages will be placed in the specified file.
Messages are always appended to the file. If the file does not
exist, it will be created. This option is ineffective in debug
mode since all relevant messages are sent to the terminal.
Determines the file that xinetd uses for configuration. The
default is /etc/xinetd.conf.
The process ID is written to the file. This option is ineffec-
tive in debug mode.
Tells xinetd to stay in the foreground rather than detaching
itself, to support being run from init or daemontools. This
option automatically sets -stayalive (see below).
Tells xinetd to stay running even if no services are specified.
This option places a limit on the number of concurrently running
processes that can be started by xinetd. Its purpose is to pre-
vent process table overflows.
This option places a limit on the number of concurrently running
servers for remote userid acquisition.
This option causes xinetd to print out its version information.
This option causes xinetd to read /etc/inetd.conf in addition to
the standard xinetd config files. /etc/inetd.conf is read after
the standard xinetd config files.
This option instructs xinetd to perform periodic consistency
checks on its internal state every interval seconds.
The syslog and filelog options are mutually exclusive. If none is
specified, the default is syslog using the daemon facility. You should
not confuse xinetd messages with messages related to service logging.
The latter are logged only if this is specified via the configuration
xinetd performs certain actions when it receives certain signals. The
actions associated with the specific signals can be redefined by edit-
ing config.h and recompiling.
SIGHUP causes a hard reconfiguration, which means that xinetd
re-reads the configuration file and terminates the
servers for services that are no longer available.
Access control is performed again on running servers by
checking the remote location, access times and server
instances. If the number of server instances is lowered,
some arbitrarily picked servers will be killed to sat-
isfy the limit; this will happen after any servers are
terminated because of failing the remote location or
access time checks. Also, if the INTERCEPT flag was
clear and is set, any running servers for that service
will be terminated; the purpose of this is to ensure
that after a hard reconfiguration there will be no run-
ning servers that can accept packets from addresses that
do not meet the access control criteria.
SIGQUIT causes program termination.
SIGTERM terminates all running servers before terminating
SIGUSR1 causes an internal state dump (the default dump file is
/var/run/xinetd.dump; to change the filename, edit con-
fig.h and recompile).
SIGIOT causes an internal consistency check to verify that the
data structures used by the program have not been cor-
rupted. When the check is completed xinetd will gener-
ate a message that says if the check was successful or
On reconfiguration the log files are closed and reopened. This allows
removal of old log files.
/etc/xinetd.conf default configuration file
/var/run/xinetd.dump default dump file
Panos Tsirigotis, CS Dept, University of Colorado, Boulder Rob Braun
evp – high-level cryptographic functions
The EVP library provides a high-level interface to cryptographic func-
EVP_Seal… and EVP_Open… provide public key encryption and decryp-
tion to implement digital „envelopes“.
The EVP_Sign… and EVP_Verify… functions implement digital signa-
Symmetric encryption is available with the EVP_Encrypt… functions.
The EVP_Digest… functions provide message digests.
Algorithms are loaded with OpenSSL_add_all_algorithms(3).
All the symmetric algorithms (ciphers) and digests can be replaced by
ENGINE modules providing alternative implementations. If ENGINE imple-
mentations of ciphers or digests are registered as defaults, then the
various EVP functions will automatically use those implementations
automatically in preference to built in software implementations. For
more information, consult the engine(3) man page.