The passwd command computes the hash of a password typed at run-time or the hash of each password in a list. The password list is taken from the named file for option -in file, from stdin for option -stdin, or from the command line, or from the terminal otherwise. The Unix standard algorithm crypt and the MD5-based BSD password algorithm 1 and its Apache variant apr1 are available.
Use the crypt algorithm (default).
Use the MD5 based BSD password algorithm 1.
Use the apr1 algorithm (Apache variant of the BSD algorithm).
Use the specified salt. When reading a password from the terminal, this implies -noverify.
Read passwords from file.
Read passwords from stdin.
Don’t verify when reading a password from the terminal.
Don’t output warnings when passwords given at the command line are truncated.
In the output list, prepend the cleartext password and a TAB character to each password hash.
openssl passwd -crypt -salt xx password prints xxj31ZMTZzkVA.
openssl passwd -1 -salt xxxxxxxx password prints $1$xxxxxxxx$UYCIxa628.9qXjpQCjM4a..
openssl passwd -apr1 -salt xxxxxxxx password prints $apr1$xxxxxxxx$dxHfLAsjHkDRmG83UXe8K0.