# phpman > man > update-ca-certificates(8)

[UPDATE-CA-CERTIFICATES(8)](https://www.chedong.com/phpMan.php/man/UPDATE-CA-CERTIFICATES/8/markdown)              System Manager's Manual             [UPDATE-CA-CERTIFICATES(8)](https://www.chedong.com/phpMan.php/man/UPDATE-CA-CERTIFICATES/8/markdown)



## NAME
       update-ca-certificates - update /etc/ssl/certs and ca-certificates.crt

## SYNOPSIS
       **update-ca-certificates** [_options_]

## DESCRIPTION
       This manual page documents briefly the **update-ca-certificates** command.

       **update-ca-certificates**  is  a  program  that updates the directory /etc/ssl/certs to hold SSL
       certificates and generates ca-certificates.crt, a concatenated single-file list  of  certifi‐
       cates.

       It  reads  the file /etc/ca-certificates.conf. Each line gives a pathname of a CA certificate
       under /usr/share/ca-certificates that should be trusted.  Lines that begin with "#" are  com‐
       ment lines and thus ignored.  Lines that begin with "!" are deselected, causing the deactiva‐
       tion of the CA certificate in question. Certificates must have a .crt extension in  order  to
       be included by update-ca-certificates.

       Furthermore  all  certificates with a .crt extension found below /usr/local/share/ca-certifi‐
       cates are also included as implicitly trusted.

       Before terminating, **update-ca-certificates** invokes **run-parts** on /etc/ca-certificates/update.d
       and calls each hook with a list of certificates: those added are prefixed with a +, those re‐
       moved are prefixed with a -.

## OPTIONS
       A summary of options is included below.

### -h, --help
              Show summary of options.

### -v, --verbose
              Be verbose. Output **openssl** **rehash**.

### -f, --fresh
              Fresh updates.  Remove symlinks in /etc/ssl/certs directory.

## FILES
       _/etc/ca-certificates.conf_
              A configuration file.

       _/etc/ssl/certs/ca-certificates.crt_
              A single-file version of CA certificates.  This holds all CA certificates that you ac‐
              tivated in /etc/ca-certificates.conf.

       _/usr/share/ca-certificates_
              Directory of CA certificates.

       _/usr/local/share/ca-certificates_
              Directory of local CA certificates (with .crt extension).

## SEE ALSO
       [**openssl**(1)](https://www.chedong.com/phpMan.php/man/openssl/1/markdown)

## AUTHOR
       This  manual  page  was written by Fumitoshi UKAI <<ukai@debian.or.jp>>, for the Debian project
       (but may be used by others).



                                            20 April 2003                  [UPDATE-CA-CERTIFICATES(8)](https://www.chedong.com/phpMan.php/man/UPDATE-CA-CERTIFICATES/8/markdown)