CRYPT(3C) Standard C Library Functions CRYPT(3C)
NAME
crypt - string encoding function
SYNOPSIS
#include <crypt.h>
char *crypt(
const char *key,
const char *salt);
Standard conforming
#include <unistd.h>
char *crypt(
const char *key,
const char *salt);
DESCRIPTION
The
crypt() function encodes strings suitable for secure storage as
passwords. It generates the password hash given the
key and
salt.
The
key argument is the plain text password to be encrypted.
If the first character of
salt is "$",
crypt() uses
crypt.conf(5) to
determine which shared module to load for the encryption algorithm. The
algorithm name
crypt() uses to search in
crypt.conf is the string between
the first and second "$", or between the first "$" and first "," if a ","
comes before the second "$".
If the first character of
salt is not "$", the algorithm described on
crypt_unix(7) is used.
RETURN VALUES
Upon successful completion,
crypt() returns a pointer to the encoded
string. Otherwise it returns a null pointer and sets
errno to indicate
the error.
The return value points to static data that is overwritten by each call.
ERRORS
The
crypt() function will fail if:
EINVAL An entry in
crypt.conf is invalid.
ELIBACC The required shared library was not found.
ENOMEM There is insufficient memory to generate the hash.
ENOSYS The functionality is not supported on this system.
USAGE
The values returned by this function might not be portable among
standard-conforming systems. See
standards(7).
Applications should not use
crypt() to store or verify user passwords but
should use the functions described on
pam(3PAM) instead.
ATTRIBUTES
See
attributes(7) for descriptions of the following attributes:
+--------------------+-----------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-----------------+
|Interface Stability | Standard |
+--------------------+-----------------+
|MT-Level | MT-Safe |
+--------------------+-----------------+
SEE ALSO
passwd(1),
crypt_genhash_impl(3C),
crypt_gensalt(3C),
crypt_gensalt_impl(3C),
getpassphrase(3C),
pam(3PAM),
passwd(5),
policy.conf(5),
attributes(7),
crypt_unix(7),
standards(7) September 28, 2004
CRYPT(3C)