Check mandatory headers of Berlin Group

obp-api/src/main/resources/props/sample.props.template

@@ -1120,6 +1120,10 @@ default_auth_context_update_request_key=CUSTOMER_NUMBER
 # Show the path inside of Berlin Group error message
 #berlin_group_error_message_show_path = true
 
+# Check presence of the mandatory headers
+#berlin_group_mandatory_headers = X-Request-ID,PSU-IP-Address,PSU-Device-ID,PSU-Device-Name
+#berlin_group_mandatory_header_consent = TPP-Redirect-URL
+
 ## Berlin Group Create Consent Frequency per Day Upper Limit
 #berlin_group_frequency_per_day_upper_limit = 4
 

obp-api/src/main/scala/code/api/util/APIUtil.scala

@@ -3244,8 +3244,8 @@ object APIUtil extends MdcLoggable with CustomJsonFormats{
       val verb = result._2.map(_.verb).getOrElse("None")
       val body = result._2.flatMap(_.httpBody)
       val reqHeaders = result._2.map(_.requestHeaders).getOrElse(Nil)
-      // Verify signed request (Berlin Group)
-      BerlinGroupSigning.verifySignedRequest(body, verb, url, reqHeaders, result)
+      // Berlin Group checks
+      BerlinGroupCheck.validate(body, verb, url, reqHeaders, result)
     } map {
       result =>
         val excludeFunctions = getPropsValue("rate_limiting.exclude_endpoints", "root").split(",").toList
@@ -3300,8 +3300,8 @@ object APIUtil extends MdcLoggable with CustomJsonFormats{
       val verb = result._2.map(_.verb).getOrElse("None")
       val body = result._2.flatMap(_.httpBody)
       val reqHeaders = result._2.map(_.requestHeaders).getOrElse(Nil)
-      // Verify signed request if need be
-      BerlinGroupSigning.verifySignedRequest(body, verb, url, reqHeaders, result)
+      // Berlin Group checks
+      BerlinGroupCheck.validate(body, verb, url, reqHeaders, result)
     } map { result =>
       result._1 match {
         case Empty if result._2.flatMap(_.consumer).isDefined => // There is no error and Consumer is defined

obp-api/src/main/scala/code/api/util/BerlinGroupCheck.scala

@@ -0,0 +1,44 @@
+package code.api.util
+
+import code.api.RequestHeader
+import com.openbankproject.commons.model.User
+import net.liftweb.common.{Box, Empty, Failure}
+import net.liftweb.http.provider.HTTPParam
+
+object BerlinGroupCheck {
+
+  // Parse mandatory headers from a comma-separated string
+  private val berlinGroupMandatoryHeaders: List[String] = APIUtil.getPropsValue("berlin_group_mandatory_headers", defaultValue = "X-Request-ID,PSU-IP-Address,PSU-Device-ID,PSU-Device-Name")
+    .split(",")
+    .map(_.trim.toLowerCase)
+    .toList.filterNot(_.isEmpty)
+  private val berlinGroupMandatoryHeaderConsent = APIUtil.getPropsValue("berlin_group_mandatory_header_consent", defaultValue = "TPP-Redirect-URL")
+    .split(",")
+    .map(_.trim.toLowerCase)
+    .toList.filterNot(_.isEmpty)
+
+  private def validateHeaders(verb: String, url: String, reqHeaders: List[HTTPParam], forwardResult: (Box[User], Option[CallContext])): (Box[User], Option[CallContext]) = {
+    val headerMap = reqHeaders.map(h => h.name.toLowerCase -> h).toMap
+    val missingHeaders = if(url.contains("berlin-group") && url.endsWith("/consent"))
+      berlinGroupMandatoryHeaders.filterNot(headerMap.contains)
+    else
+      (berlinGroupMandatoryHeaders ++ berlinGroupMandatoryHeaderConsent).filterNot(headerMap.contains)
+
+    if (missingHeaders.isEmpty) {
+      forwardResult // All mandatory headers are present
+    } else {
+      (Failure(s"Missing mandatory headers: ${missingHeaders.mkString(", ")}"), forwardResult._2)
+    }
+  }
+
+  def validate(body: Box[String], verb: String, url: String, reqHeaders: List[HTTPParam], forwardResult: (Box[User], Option[CallContext])): (Box[User], Option[CallContext]) = {
+    validateHeaders(verb, url, reqHeaders, forwardResult) match {
+      case (user, _) if user.isDefined || user == Empty => // All good. Chain another check
+        // Verify signed request (Berlin Group)
+        BerlinGroupSigning.verifySignedRequest(body, verb, url, reqHeaders, forwardResult)
+      case forwardError => // Forward error case
+        forwardError
+    }
+  }
+
+}