openssl rehash -help

[saolasosme]

Create symbolic links to certificate and CRL files named by the hash values.

$ openssl rehash -help
Usage: rehash [options] [cert-directory...]
Valid options are:
 -help    Display this summary
 -h       Display this summary
 -compat  Create both new- and old-style hash links
 -old     Use old-style hash to generate links
 -n       Do not remove existing links
 -v       Verbose output