get signature

SignUtils.kt

// https://stackoverflow.com/a/53407183
fun Context.getApplicationSignature(packageName: String): List<String> {
    val signatureList: List<String>
    try {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P) {
            // New signature
            val sig = packageManager.getPackageInfo(packageName, PackageManager.GET_SIGNING_CERTIFICATES).signingInfo
            signatureList = if (sig.hasMultipleSigners()) {
                // Send all with apkContentsSigners
                sig.apkContentsSigners.map {
                    val digest = MessageDigest.getInstance("SHA")
                    digest.update(it.toByteArray())
                    digest.digest().toHexString()
                }
            } else {
                // Send one with signingCertificateHistory
                sig.signingCertificateHistory.map {
                    val digest = MessageDigest.getInstance("SHA")
                    digest.update(it.toByteArray())
                    digest.digest().toHexString()
                }
            }
        } else {
            val sig = packageManager.getPackageInfo(packageName, PackageManager.GET_SIGNATURES).signatures
            signatureList = sig.map {
                val digest = MessageDigest.getInstance("SHA")
                digest.update(it.toByteArray())
                digest.digest().toHexString()
            }
        }

        return signatureList
    } catch (e: Exception) {
        // Handle error
    }
    return emptyList()
}

fun ByteArray.toHexString() = joinToString("") { "%02x".format(it).toUpperCase(Locale.ROOT) }