Test GnuPG verification of a detached signature

test-detached-verification.bash

command_status() {
    if [ $1 = '0' ]; then
        echo $'\e[1;32m'Result: Success$'\e[0m'
    else
        echo $'\e[1;31m'Result: Failure \(exit code = $1\)$'\e[0m'
    fi
}

GPG=gpg2
rm -rf keys
mkdir -p keys
chmod 0700 keys
killall gpg-agent > /dev/null 2>&1
cat << EOF > key_data.txt
Key-Type: DSA
Key-Length: 1024
Subkey-Type: ELG-E
Subkey-Length: 2048
Name-Comment: A test user
Name-Real: Andrew Able
Name-Email: andrew.able@example.com
Passphrase: aable
Expire-Date: 0
%commit
EOF
COMMON_ARGS="--status-fd 2 --no-tty --no-verbose --fixed-list-mode --batch --with-colons --homedir keys"
echo $'\e[1;33m'GPG version ...$'\e[0m'
${GPG} ${COMMON_ARGS} --version | head -1
echo $'\e[1;33m'Generating a key ...$'\e[0m'
${GPG} ${COMMON_ARGS} --gen-key < key_data.txt 2>&1 | tee key_info.txt
command_status $?
KEYID=$(tail -1 key_info.txt | awk  '{ print $(NF)}')
# echo $'\e[1;33m'Key ID: ${KEYID}$'\e[0m'
rm key_data.txt key_info.txt
echo $'\e[1;33m'Creating random data to sign ...$'\e[0m'
dd if=/dev/urandom of=data-to-sign bs=1 count=1024 > /dev/null 2>&1
echo $'\e[1;33m'Signing data, asking for a detached signature ...$'\e[0m'
echo aable | ${GPG} --pinentry-mode loopback ${COMMON_ARGS} --passphrase-fd 0 -sa --detach-sign --default-key ${KEYID} | tee sig.asc
command_status $?
echo $'\e[1;33m'Trying to verify data ...$'\e[0m'
${GPG} ${COMMON_ARGS} --verify sig.asc data-to-sign
command_status $?