CHPASSWD(8) (System Management Commands) (NAME) chpasswd - (SYNOPSIS) chpasswd [] (DESCRIPTION) chpasswd . : user_name:password chpasswd . . PAM ( ) -e -c . PAM chpasswd . PAM ( ) chpasswd . . (OPTIONS) chpasswd : -c, --crypt-method METHOD . : SHA256 SHA512 YESCRYPT NONE libc . PAM . -e, --encrypted . -h, --help . -R, --root CHROOT_DIR CHROOT_DIR CHROOT_DIR. . SELinux . -P, --prefix PREFIX_DIR PREFIX_DIR. chroot . : / NIS LDAP . PAM . SELinux . -s, --sha-rounds ROUNDS . : SHA256 SHA512 YESCRYPT SHA256 SHA512 SHA_CRYPT_MIN_ROUNDS SHA_CRYPT_MAX_ROUNDS /etc/login.defs . 1000 999,999,999 SHA256 SHA512 . 5000 . YESCRYPT YESCRYPT_COST_FACTOR /etc/login.defs . 1 11 YESCRYPT . 5 . (CAVEATS) umask . (CONFIGURATION) /etc/login.defs : SHA_CRYPT_MIN_ROUNDS () SHA_CRYPT_MAX_ROUNDS () ENCRYPT_METHOD SHA256 SHA512 SHA ( ). . . libc (5000) . 1000 999,999,999 . SHA_CRYPT_MIN_ROUNDS SHA_CRYPT_MAX_ROUNDS . SHA_CRYPT_MIN_ROUNDS > SHA_CRYPT_MAX_ROUNDS . : . PAM PAM . PAM . YESCRYPT_COST_FACTOR () ENCRYPT_METHOD YESCRYPT ( ). . . 1 11 . : . PAM PAM . PAM . (FILES) /etc/passwd . /etc/shadow . /etc/login.defs Shadow. /etc/pam.d/chpasswd PAM chpasswd. (SEE ALSO) passwd(1) newusers(8) login.defs(5) useradd(8). shadow-utils 4.20.0 07/30/2026 CHPASSWD(8)