Shell script that takes android /data/system/packages.xml as input and print the containing certificates

packagexml_certs.sh

#!/bin/bash
input="$1"
while IFS= read -r line
do
  line1=`echo "$line" | egrep 'cert index="[0-9]+" key="[0-9a-z]+"'`
  if [ $? -eq 0 ]
  then
	  index=`echo $line1 | grep -oP 'index="\K\d+'`
	  hex=`echo $line1 | grep -oP 'key="\K[0-9a-z]+'`
	  sslinfo=`echo $hex | xxd -p -r | openssl x509 -inform DER -in /dev/stdin -text`
	  email=`echo "$sslinfo" | grep emailAddress`
	  pubkeycert=`echo $hex | xxd -p -r | openssl x509 -inform DER -in /dev/stdin -pubkey`
	  pubkey=`echo "$pubkeycert" | pcregrep -M -- '-----BEGIN PUBLIC KEY-----(\n|.)*-----END PUBLIC KEY-----'`
	  pubkey=`echo "$pubkey" | tr -d '\n'`

	  if [ -n "$email" ]
	  then
		  echo "$index : $email"
		  echo "$pubkey"
	  fi
  fi
done < "$input"

pems_pubkey.sh

#!/bin/bash

for f in /tmp/*.pem
do
    echo "===============$f=============="
    openssl x509 -inform PEM -in $f -pubkey
done