Get a (self-signed) SSL certificate for Ubuntu 10.10

getcert

#!/bin/bash

HOSTNAME=$1
TMPFILE=`mktemp`
FNAME=$HOSTNAME.crt

expect_cmd() {
    cmd=$1
    package=$2
    which $cmd &> /dev/null
    if [[ $? != 0 ]]; then
        echo "ERROR: Tool needed: '$cmd'. Try"
        echo "    sudo apt-get install $package"
        exit 1
    fi
}
expect_cmd unix2dos tofrodos
expect_cmd openssl openssl

# We need a "here document" [1] for input (i.e. the QUIT command) and
# a subshell [2] to be able to pipe the output.
# Then we use sed to cut irrelevant lines and convert LFs to CRLFs.
# [1] http://tldp.org/LDP/abs/html/here-docs.html
# [2] http://stackoverflow.com/questions/2128949/how-to-pipe-a-here-document-through-a-command-and-capture-the-result-into-a-varia
(openssl s_client -connect $HOSTNAME:443 << EOF
QUIT
EOF
) 2> /dev/null | sed -n '/-----BEGIN CERTIFICATE-----/,/-----END CERTIFICATE-----/p' | tee | unix2dos > $TMPFILE

echo "copying to /usr/local/share/ca-certificates/, ok?"
read || exit 1

echo "verifying and installing"
openssl verify $TMPFILE && (
    sudo cp $TMPFILE /usr/local/share/ca-certificates/$FNAME
    sudo update-ca-certificates
)