halkyon/tool/with_signing_keys.sh

#!/usr/bin/env bash
# Runs a release with its signing keys fetched from Proton Pass, where alone they are
# kept (vault "Infra · Signing"): the app's Android keystore and the F-Droid index's,
# each a note's attachment, downloaded into a folder in memory ($XDG_RUNTIME_DIR, a
# tmpfs only the own user reads), handed to the release tool by the variables it reads
# their paths from, and removed however the run ends. Their passwords, each item's hidden
# field "Password", go to it in its environment (<keystore variable>_PASSWORD), so it
# asks for none; a dry run asks for no secret, and gets none.
#
#   tool/with_signing_keys.sh <app> [release.dart's arguments]
#   tool/with_signing_keys.sh train minor --dry-run
#
# Needs pass-cli, logged in (pass-cli login), and jq. Reads of the items take their IDs,
# their attachments' names and, but for a dry run, the field "Password", which goes
# nowhere but into the release tool's environment.
set -euo pipefail
cd "$(git rev-parse --show-toplevel)"

readonly vault='Infra · Signing'

fail() {
  echo "✗ $*" >&2
  exit 1
}

[ $# -ge 1 ] || fail 'Usage: tool/with_signing_keys.sh <app> [release arguments]'
app="$1"
shift

# Each app released (tool/src/release/apps.dart): the variable its keystore's path goes
# in (its AndroidSigning's keystoreVariable) and the item keeping it.
case "$app" in
  learn) app_variable=HALKYON_ANDROID_KEYSTORE app_item='Halkyon Learn – Android release keystore' ;;
  train) app_variable=HALKYON_TRAIN_ANDROID_KEYSTORE app_item='Halkyon Train – Android release keystore' ;;
  *) fail "No signing key known for $app." ;;
esac
# The F-Droid repository's index key, the same for every app listed there.
readonly fdroid_item='Halkyon Learn – F-Droid index keystore'

for tool in pass-cli jq; do
  command -v "$tool" >/dev/null || fail "$tool is missing."
done
[ -n "${XDG_RUNTIME_DIR:-}" ] && [ -d "$XDG_RUNTIME_DIR" ] ||
  fail 'No $XDG_RUNTIME_DIR to keep the keys in memory.'

keys=$(mktemp -d -p "$XDG_RUNTIME_DIR")
trap 'rm -rf "$keys"' EXIT
trap 'exit 130' INT TERM HUP

# Downloads the attachment named $2 of the item titled $1 to $3.
fetch() {
  local item="$1" name="$2" to="$3" ids
  ids=$(pass-cli item view --vault-name "$vault" --item-title "$item" --output json |
    jq -r --arg name "$name" \
      '[.item.share_id, .item.id, (.attachments[] | select(.content.name == $name) | .id)]
       | select(length == 3) | @tsv') ||
    fail "Can't read the item \"$item\" in $vault (pass-cli login?)."
  [ -n "$ids" ] || fail "The item \"$item\" in $vault has no attachment $name."
  local share item_id attachment
  IFS=$'\t' read -r share item_id attachment <<<"$ids"
  pass-cli item attachment download --share-id "$share" --item-id "$item_id" \
    --attachment-id "$attachment" --output "$to" >/dev/null
  [ -s "$to" ] || fail "The attachment $name of \"$item\" came empty."
}

# The hidden field "Password" of the item titled $1.
password() {
  local item="$1" value
  value=$(pass-cli item view --vault-name "$vault" --item-title "$item" --output json |
    jq -r '.item.content.extra_fields[]? | select(.name == "Password") | .content.Hidden // empty') ||
    fail "Can't read the item \"$item\" in $vault (pass-cli login?)."
  [ -n "$value" ] || fail "The item \"$item\" in $vault has no field Password."
  printf '%s' "$value"
}

echo "▸ Fetching the signing keys from $vault"
fetch "$app_item" android-release.p12 "$keys/android-release.p12"
fetch "$fdroid_item" fdroid-index.p12 "$keys/fdroid-index.p12"

export "$app_variable=$keys/android-release.p12"
export HALKYON_FDROID_KEYSTORE="$keys/fdroid-index.p12"
dry_run=false
for argument in "$@"; do
  [ "$argument" = --dry-run ] && dry_run=true
done
if ! $dry_run; then
  app_password=$(password "$app_item")
  fdroid_password=$(password "$fdroid_item")
  export "${app_variable}_PASSWORD=$app_password"
  export HALKYON_FDROID_KEYSTORE_PASSWORD="$fdroid_password"
  unset app_password fdroid_password
fi
status=0
dart run tool/release.dart "$app" "$@" || status=$?
exit "$status"