kotlincryptocurrencyrippled

Since ripple-lib-java is unmaintained, how do you manually sign a transaction?


Looking for a lightweight way to manually sign an OfferCreate ... it would be clumsy to start some JavaScript engine in order to get it done.


Solution

  • Hmm ... even though it hasn't been maintained for 4 years it looks like it still works.

    Clone ripple-lib-java and do mvn install in ripple-bouncycastle & ripple-core

    Then copy the built JARs into <YourProject>/libs

    Add local dependencies in Gradle Kotlin DSL:

    repositories {
        flatDir {
            dirs("libs")
        }
    }
    
    dependencies {
        implementation(":ripple-bouncycastle-0.0.1-SNAPSHOT")
        implementation(":ripple-core-0.0.1-SNAPSHOT")
    
        runtime("org.json:json:20190722") // No newskool kotlinx-serialization here :(
    }
    

    Create & sign OfferCreate:

    val offerCreate = OfferCreate()
    offerCreate.account(AccountID.fromString("r3jpWpUysF4SAkUNbG4WhDZ5mAJ7rGUDx6"))
    offerCreate.expiration(UInt32(get2MinExpiration()))
    offerCreate.fee(Amount(BigDecimal("0.00001")))
    offerCreate.flags(UInt32(0))
    offerCreate.sequence(UInt32(1))
    val amountXRP = BigDecimal(200)
    val amountBTC = convert(amountXRP, RIPPLE_XRP, BITCOIN)
    offerCreate.takerGets(Amount(amountXRP))
    offerCreate.takerPays(Amount(amountBTC, Currency.fromString(BITCOIN), AccountID.fromString(BITCOIN_TRUSTED_ISSUER)))
    val signedTransaction = offerCreate.sign("[***Secret***]")
    println(offerCreate.toJSON())
    println(signedTransaction.tx_blob)
    

    A bit annoying that you can't do a toJSON() on a SignedTransaction. It can t be a security thing, since sign() only adds public key fields: https://xrpl.org/transaction-common-fields.html#signers-field