io.github.binaryfoo.decoders.apdu.InternalAuthenticateAPDUDecoder.kt Maven / Gradle / Ivy

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Some decoders for the data used in EMV credit card transactions.

There is a newer version: 0.1.8

package io.github.binaryfoo.decoders.apdu

import io.github.binaryfoo.DecodedData
import io.github.binaryfoo.decoders.DecodeSession
import io.github.binaryfoo.decoders.PopulatedDOLDecoder
import io.github.binaryfoo.EmvTags
import java.util.logging.Logger
import kotlin.collections.listOf
import kotlin.text.substring

class InternalAuthenticateAPDUDecoder : CommandAPDUDecoder {
    override fun getCommand(): APDUCommand {
        return APDUCommand.InternalAuthenticate
    }

    override fun decode(input: String, startIndexInBytes: Int, session: DecodeSession): DecodedData {
        val length = Integer.parseInt(input.substring(8, 10), 16)
        val data = input.substring(10, 10 + length * 2)
        val ddolValues = decodeDDOLElements(session, data, startIndexInBytes + 5)
        return DecodedData.constructed("C-APDU: Internal Authenticate", data, startIndexInBytes, startIndexInBytes + 6 + length, ddolValues)
    }

    private fun decodeDDOLElements(session: DecodeSession, populatedDdol: String, startIndexInBytes: Int): List {
        val cdol = session[EmvTags.DDOL]
        if (cdol != null) {
            try {
                return PopulatedDOLDecoder().decode(cdol, populatedDdol, startIndexInBytes, session)
            } catch (e: Exception) {
                LOG.throwing(GenerateACAPDUDecoder::class.java.simpleName, "decodeDDOLElements", e)
            }

        }
        return listOf()
    }

    companion object {
        private val LOG = Logger.getLogger(InternalAuthenticateAPDUDecoder::class.java.name)
    }

}