pem-foreach

#! /bin/sh
# pem-foreach (Bourne shell script) -- run openssl on each cert in a .pem file

OUTDIR=/tmp/pem-$$

set -e

mkdir $OUTDIR
echo $OUTDIR >&2

# open a given file (if supplied) as stdin
if [ $# -gt 0 ] ; then
  if [ "x$1" != x- -a "x$1" != x-- ] ; then
    # it's a filename
    exec < "$1"
  fi
  shift
  if [ "x$1" = x-- ] ; then
    # this accounts for the case where a filename or - was present before the --
    # (if not, the -- was already removed above)
    shift
  fi
fi


count=0
started=n
while read line
do
  if [ "$line" = "-----BEGIN CERTIFICATE-----" ] ; then
    # switch output filenames
    count=$(expr $count + 1)
    filename=$OUTDIR/$count.crt
    exec 5> $filename
    started=y
  fi

  if [ $started = y ] ; then
    echo "$line" >&5
  fi

  # if the cert is finished and any command line arguments were present other
  # than a filename, invoke OpenSSL on the cert
  if [ $# -gt 0 -a "$line" = "-----END CERTIFICATE-----" ] ; then
    # close the file
    exec 5> /dev/null
    started=n
    openssl x509 "$@" -noout -in $filename
  fi
done