Using flock for SSL key generation

flock demo

#!/bin/bash
set -eu
set -o pipefail


MY_CRT=temp.crt
MY_KEY=temp.key
MY_CSR=temp.csr
CLIENTID=`sed -e 's/://g' /sys/class/net/eth0/address`
SUBJECT="/C=XX/ST=TESTING/L=Testing/O=Test Inc/OU=Test Dept/CN=$CLIENTID"

echo $SUBJECT
export SUBJECT MY_CRT MY_KEY MY_CSR

# define a gencsr function
gencsr(){
    # Returns != 0 if this fails
    if ! openssl pkey -noout -in $MY_KEY &>/dev/null
    then
        rm -f $MY_KEY $MY_CRT $MY_CSR
        openssl genrsa -out $MY_KEY 2048 &>/dev/null
    fi
    # Validate the CSR is from the same key. and not invalid.
    if ! openssl req -noout -verify -in $MY_CSR -key $MY_KEY &>/dev/null
    then
        rm -f $MY_CSR $MY_CRT
        openssl req -sha256 -utf8 -new -key $MY_KEY -out $MY_CSR -subj "$SUBJECT" &>/dev/null
    fi
}
export -f gencsr
flock -xn $MY_KEY -c '/bin/bash -c gencsr'

wow thats nice
many thanks
such ssl 😄