check Linux password from /etc/shadow and C language
Hi.
I want to write a C Program that get a user name and password , then compare it with encrypted password in /etc/shadow.
I start with below program:
And then compile that:
The out put of compile is:
What is the problem?
Does anyone know how to remove a stanza in the shadow password file if the user account has already been removed on an AIX box? I know it can be done by editing the file itself but I would prefer not to do it that way.
cheers
gizaa (2 Replies)
Hi,
I want to append password into /etc/shadow file using a shell script.
My below script does add the users to both /etc/passwd and /etc/shadow but how can I add the hordcoded passwords to /etc/shadow file can some one help me ?
# To add the groups into /etc/group file
for a_user... (5 Replies)
hi,
I had to reset a lost root password by editing the /etc/passwd and /etc/shadow files ( this is a xen vm file, so i mounted and chrooted the file )
after the reboot with an empty password on root , i have set a new password with passwd but
it only changed the /etc/passwd file.... (0 Replies)
We are currently using a script to copy the same encrypted password between our HP-UX and Solaris servers editing the trusted and shadow files directly. The encrypted password is only 13 characters long on both servers and decrypts the same way. Is there a way to copy this same string to Linux... (5 Replies)
Hello,
I want to know the reason behing the scene why some systems have hashed password in /etc/shadow file as "x" not the alienoid language like A1Dksxi3kaA.. (13 characters)
As far as I understand, etc/password will show password as "x" and move all hashed password to etc/shadow.... (8 Replies)
Hi
I wonder whether is possible to generate enrypted passwd for some user and paste it into /etc/shadow file ?
What kind of encryption is used in /etc/shadow file ?
ths for help. (1 Reply)
Today i was going through some of security guides written on linux .
Under shadow file security following points were mentioned.
1)The encrypted password stored under /etc/shadow file should have more than 14-25 characters.
2)Usernames in shadow file must satisfy to all the same rules as... (14 Replies)
Hello,
I have to do a script which returns users who have never changed their password from /etc/shadow.
Here is what have I done and I'm not sure if it's ok.
I tried to return just users who doesn;t have password set or are locked.
Can be there other kind of user who never changed the... (3 Replies)
i have an application that uses the encrypted password that's in the /etc/shadow file.
i copied the line for the particular username i was interested it in from shadow file and i pasted it into the password file of the application. the application is nagios.
this application allowed that... (5 Replies)
Discussion started by: SkySmart
5 Replies
LEARN ABOUT MINIX
pwdauth
PWDAUTH() PWDAUTH()
NAME
pwdauth - password authentication program
SYNOPSIS
/usr/lib/pwdauth
DESCRIPTION
Pwdauth is a program that is used by the crypt(3) function to do the hard work. It is a setuid root utility so that it is able to read the
shadow password file.
Pwdauth expects on standard input two null terminated strings, the password typed by the user, and the salt. That is, the two arguments of
the crypt function. The input read in a single read call must be 1024 characters or less including the nulls. Pwdauth takes one of two
actions depending on the salt.
If the salt has the form "##user" then the user is used to index the shadow password file to obtain the encrypted password. The input
password is encrypted with the one-way encryption function contained within pwdauth and compared to the encrypted password from the shadow
password file. If equal then pwdauth returns the string "##user" with exit code 0, otherwise exit code 2 to signal failure. The string
"##user" is also returned if both the shadow password and the input password are null strings to allow a password-less login.
If the salt is not of the form "##user" then the password is encrypted and the result of the encryption is returned. If salt and password
are null strings then a null string is returned.
The return value is written to standard output as a null terminated string of 1024 characters or less including the null.
The exit code is 1 on any error.
SEE ALSO crypt(3), passwd(5).
NOTES
A password must be checked like in this example:
pw_ok = (strcmp(crypt(key, pw->pw_passwd), pw->pw_passwd) == 0);
The second argument of crypt must be the entire encrypted password and not just the two character salt.
AUTHOR
Kees J. Bot (kjb@cs.vu.nl)
PWDAUTH()