RT1941: c_rehash.pod is missing

=pod

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Original text by James Westby, contributed under the OpenSSL license.

=head1 NAME

c_rehash - Create symbolic links to files named by the hash values

=head1 SYNOPSIS

B<c_rehash>

[ I<directory>...]

=head1 DESCRIPTION

B<c_rehash> scans directories and calculates a hash value of each C<.pem>

file in the specified directory list and creates symbolic links

for each file, where the name of the link is the hash value.

This utility is useful as many programs that use OpenSSL require

directories to be set up like this in order to find certificates.

If any directories are named on the command line, then those are

processed in turn. If not, then the B<SSL_CERT_DIR> environment variable

is consulted; this shold be a colon-separated list of directories,

like the Unix B<PATH> variable.

If that is not set then the default directory (installation-specific

but often B</usr/local/ssl/certs>) is processed.

In order for a directory to be processed, the user must have write

permissions on that directory, otherwise it will be skipped.

The links created are of the form C<HHHHHHHH.D>, where each B<H>

is a hexadecimal character and B<D> is a single decimal digit.

When processing a directory, B<c_rehash> will first remove all links

that have a name in that syntax. If you have links in that format

used for other purposes, they will be removed.

Hashes for CRL's look similar except the letter B<r> appears after

the period, like this: C<HHHHHHHH.rD>.

Multiple objects may have the same hash; they will be indicated by

incrementing the B<D> value. Duplicates are found by comparing the

full SHA-1 fingerprint. A warning will be displayed if a duplicate

is found.

A warning will also be displayed if there are B<.pem> files that

cannot be parsed as either a certificate or a CRL.

The program uses the B<openssl> program to compute the hashes and

fingerprints. If not found in the user's B<PATH>, then set the

B<OPENSSL> environment variable to the full pathname.

Any program can be used, it will be invoked as follows for either

a certificate or CRL:

  $OPENSSL x509 -hash -fingerprint -noout -in FFFFFF

  $OPENSSL crl -hash -fingerprint -noout -in FFFFFF

where B<FFFFFF> is the filename. It must output the hash of the

file on the first line, and the fingerprint on the second,

optionally prefixed with some text and an equals sign.

=head1 ENVIRONMENT

=over

=item B<OPENSSL>

The path to an executable to use to generate hashes and

fingerprints (see above).

=item B<SSL_CERT_DIR>

Colon separated list of directories to operate on.

Ignored if directories are listed on the command line.

=back

=head1 SEE ALSO

L<openssl(1)|openssl(1)>,

L<crl(1)|crl(1)>.

L<x509(1)|x509(1)>.