This script generates the SMS Retriever API hash code required by Android applications.

sms_retriever_hash.sh

#!/bin/sh
set -euf

VERSION=0.1.1
USAGE="Usage: sms_retriever_hash.sh --package <package_name> --keystore <keystore_file>"

# --- helpers ---
die() { printf '%s\n' "Error: $*" >&2; exit 1; }
need() { command -v "$1" >/dev/null 2>&1 || die "Missing dependency: $1"; }

# --- parse args ---
pkg=""
keystore=""

while [ "$#" -gt 0 ]; do
  case "$1" in
    --package)
      [ "$#" -ge 2 ] || die "Missing value for --package"
      pkg=$2; shift 2 ;;
    --keystore)
      [ "$#" -ge 2 ] || die "Missing value for --keystore"
      keystore=$2; shift 2 ;;
    -h|--help)
      printf '%s\n' "$USAGE"; exit 0 ;;
    *)
      die "Unknown argument: $1";;
  esac
done

[ -n "${pkg}" ] || die "Package name is required. $USAGE"
[ -n "${keystore}" ] || die "Keystore file is required. $USAGE"

# reject paths that start with '-'
case "$keystore" in
  -*) die "Keystore path must not start with '-'";;
esac

# --- dependencies ---
need keytool
need sed
need tr
need xxd
need shasum
need base64
need awk
need cut

# macOS vs GNU base64 flag
if base64 --help 2>/dev/null | grep -q -- '--decode'; then
  B64_DEC='--decode'
else
  B64_DEC='-D'
fi

# --- validations ---
[ -f "$keystore" ] || die "File not found: $keystore"

printf '\npackage name: %s\nkeystore file: %s\n\n' "$pkg" "$keystore"

# --- extract certificate (hex) safely ---
# Pull PEM body between BEGIN/END CERTIFICATE, remove spaces/newlines, base64-decode, then to hex
cert_hex=$(
  keytool -list -rfc -keystore "$keystore" 2>/dev/null \
  | awk '/BEGIN CERTIFICATE/{f=1;next} /END CERTIFICATE/{f=0} f' \
  | tr -d ' \n' \
  | base64 $B64_DEC \
  | xxd -p -c 256 \
  | tr -d ' \n'
)

[ -n "$cert_hex" ] || die "Failed to extract certificate from keystore (wrong password or invalid keystore?)"

printf '\ncertificate in hex: %s\n' "$cert_hex"

# --- compute SHA-256 over "pkg + space + cert_hex" ---
input="${pkg} ${cert_hex}"
sha256_hex=$(printf '%s' "$input" | shasum -a 256 | cut -c1-64)

printf '\nSHA-256 output in hex: %s\n' "$sha256_hex"

# first 18 hex chars (9 bytes)
first18=$(printf '%s' "$sha256_hex" | cut -c1-18)

# convert to bytes then base64 and take first 11 chars
hash11=$(printf '%s' "$first18" | xxd -r -p | base64 | cut -c1-11)

printf '\nFirst 8 bytes encoded by base64: %s\n' "$hash11"
printf '\nSMS Retriever hash code:  %s\n\n' "$hash11"