Encoding a password with argon2 and save on PostgreSQL - kotlin

Question

I'm trying to encox user password to save in postgresql database. Using kotlin and argon2. I did the functions and in the tests, it works perfectly. But when I save it in the database, and I try to compare the passwords, it always gives an error. Could anyone help?
I created the following functions:
private val argon2 = Argon2Factory.create(Argon2Factory.Argon2Types.ARGON2id, 32, 64)
fun String.encode(): String = argon2.hash(3, 64 * 1024, 1, this.toCharArray())
fun String.checkEncoding(hash: String): Boolean = argon2.verify(hash, this.toCharArray())
and in tests, everything works perfectly
class HashingTest : ShouldSpec({
context("Encoding a string") {
should("encode correctly") {
val dataOne = "S#!sc_%kah"
val encondeOne = dataOne.encode()
val dataTwo = "S#!sc_%kah"
dataTwo.checkEncoding(encondeOne) shouldBe true // works fine!
}
}
})
When I save to the database, and try to compare, I always get an error
//ENTITY
data class User(
override val id: UUID,
val username: String,
val password: String,
) : IEntity
//INSERT SCRITP -> EXPOSED FRAMEWORK
private fun newUser(schema: String, entity: User) {
val table = toUserTable(schema)
table
.insert {
it[id] = entity.id
it[username] = entity.username
it[password] = entity.password.encode()
}
}
//FIND USER
fun findUser(schema: String, model: SignInModel): User? {
val table = toUserTable(schema)
val user = table
.select { table.username eq model.username }
.firstNotNullOfOrNull { toUser(schema, it) }
val verifying = model.password.checkEncoding(user!!.password) // ERROR HERE, ALWAYS RETURNS FALSE
return when (verifying) {
true -> user
false -> null
}
}

Answer 1

I don't know if you used your findUser() and newUser() in a transaction but queries must be called in a transaction like below:
private fun newUser(schema: String, entity: User) {
val table = toUserTable(schema)
transaction {
table
.insert {
it[id] = entity.id
it[username] = entity.username
it[password] = entity.password.encode()
}
}
}
and:
fun findUser(schema: String, model: SignInModel): User? {
val table = toUserTable(schema)
val user = transaction {
table
.select { table.username eq model.username }
.firstNotNullOfOrNull { toUser(schema, it) }
}
val verifying = model.password.checkEncoding(user!!.password)
return when (verifying) {
true -> user
false -> null
}
}