Provided by: openssl_1.0.1f-1ubuntu2.27_amd64 

NAME
c_rehash - Create symbolic links to files named by the hash values
SYNOPSIS
c_rehash [directory] ...
DESCRIPTION
c_rehash scans directories and takes a hash value of each .pem and .crt file in the directory. It then
creates symbolic links for each of the files named by the hash value. This is useful as many programs
require directories to be set up like this in order to find the certificates they require.
If any directories are named on the command line then these directories are processed in turn. If not
then and the environment variable SSL_CERT_DIR is defined then that is consulted. This variable should be
a colon (:) separated list of directories, all of which will be processed. If neither of these conditions
are true then /usr/lib/ssl/certs is processed.
For each directory that is to be processed he user must have write permissions on the directory, if they
do not then nothing will be printed for that directory.
Note that this program deletes all the symbolic links that look like ones that it creates before
processing a directory. Beware that if you run the program on a directory that contains symbolic links
for other purposes that are named in the same format as those created by this program they will be lost.
The hashes for certificate files are of the form <hash>.<n> where n is an integer. If the hash value
already exists then n will be incremented, unless the file is a duplicate. Duplicates are detected using
the fingerprint of the certificate. A warning will be printed if a duplicate is detected. The hashes for
CRL files are of the form <hash>.r<n> and have the same behavior.
The program will also warn if there are files with extension .pem which are not certificate or CRL files.
The program uses the openssl program to compute the hashes and fingerprints. It expects the executable to
be named openssl and be on the PATH, or in the /usr/lib/ssl/bin directory. If the OPENSSL environment
variable is defined then this is used instead as the executable that provides the hashes and
fingerprints. When called as $OPENSSL x509 -hash -fingerprint -noout -in $file it must output the hash of
$file on the first line followed by the fingerprint on the second line, optionally prefixed with some
text and an equals sign (=).
OPTIONS
None
ENVIRONMENT
OPENSSL
The name (and path) of an executable to use to generate hashes and fingerprints (see above).
SSL_CERT_DIR
Colon separated list of directories to operate on. Ignored if directories are listed on the command
line.
SEE ALSO
openssl(1), x509(1)
BUGS
No known bugs
1.0.1f 2018-12-04 C_REHASH(1SSL)