AuthAwareTokenConverter.kt

package uk.gov.justice.hmpps.probationsearch.security

import org.springframework.core.convert.converter.Converter
import org.springframework.security.authentication.AbstractAuthenticationToken
import org.springframework.security.core.GrantedAuthority
import org.springframework.security.core.authority.SimpleGrantedAuthority
import org.springframework.security.oauth2.jwt.Jwt
import org.springframework.security.oauth2.server.resource.authentication.JwtAuthenticationToken
import org.springframework.security.oauth2.server.resource.authentication.JwtGrantedAuthoritiesConverter

class AuthAwareTokenConverter : Converter<Jwt, AbstractAuthenticationToken> {
  private val jwtGrantedAuthoritiesConverter: Converter<Jwt, Collection<GrantedAuthority>> =
    JwtGrantedAuthoritiesConverter()

  override fun convert(jwt: Jwt): AbstractAuthenticationToken {
    return AuthAwareAuthenticationToken(
      jwt = jwt,
      clientOnly = jwt.subject == jwt.claims["client_id"],
      subject = jwt.subject,
      deliusUser = "delius" == jwt.claims["auth_source"],
      authorities = extractAuthorities(jwt),
    )
  }

  private fun extractAuthorities(jwt: Jwt): Collection<GrantedAuthority> {
    val authorities = mutableListOf<GrantedAuthority>().apply { addAll(jwtGrantedAuthoritiesConverter.convert(jwt)!!) }
    if (jwt.claims.containsKey("authorities")) {
      @Suppress("UNCHECKED_CAST")
      val claimAuthorities = (jwt.claims["authorities"] as Collection<String>).toList()
      authorities.addAll(claimAuthorities.map(::SimpleGrantedAuthority))
    }
    return authorities.toSet()
  }
}

class AuthAwareAuthenticationToken(
  jwt: Jwt,
  val clientOnly: Boolean,
  val deliusUser: Boolean,
  val subject: String,
  authorities: Collection<GrantedAuthority>,
) : JwtAuthenticationToken(jwt, authorities)