From e1d4f76046488cb3a3b131c777e1e61de6d29ac3 Mon Sep 17 00:00:00 2001
From: Markus Gylling <markus.gylling@gmail.com>
Date: Wed, 31 Aug 2022 22:44:22 +0200
Subject: [PATCH] add credential subject probe

---
 .../oneedtech/inspect/vc/OB30Inspector.java   |  7 ++--
 .../vc/probe/CredentialSubjectProbe.java      | 42 +++++++++++++++++++
 2 files changed, 46 insertions(+), 3 deletions(-)
 create mode 100644 inspector-vc/src/main/java/org/oneedtech/inspect/vc/probe/CredentialSubjectProbe.java

diff --git a/inspector-vc/src/main/java/org/oneedtech/inspect/vc/OB30Inspector.java b/inspector-vc/src/main/java/org/oneedtech/inspect/vc/OB30Inspector.java
index 02d532f..c49bd80 100644
--- a/inspector-vc/src/main/java/org/oneedtech/inspect/vc/OB30Inspector.java
+++ b/inspector-vc/src/main/java/org/oneedtech/inspect/vc/OB30Inspector.java
@@ -31,6 +31,7 @@ import org.oneedtech.inspect.util.resource.UriResource;
 import org.oneedtech.inspect.util.resource.context.ResourceContext;
 import org.oneedtech.inspect.util.spec.Specification;
 import org.oneedtech.inspect.vc.Credential.Type;
+import org.oneedtech.inspect.vc.probe.CredentialSubjectProbe;
 import org.oneedtech.inspect.vc.probe.ContextPropertyProbe;
 import org.oneedtech.inspect.vc.probe.CredentialParseProbe;
 import org.oneedtech.inspect.vc.probe.ExpirationVerifierProbe;
@@ -91,9 +92,7 @@ public class OB30Inspector extends VCInspector {
 				
 				//we expect the above to place a generated object in the context				
 				Credential crd = ctx.getGeneratedObject(Credential.ID);
-								
-				//TODO new check: that subject @id or IdentityObject is available (at least one is the req)
-								
+																				
 				//context and type properties
 				Credential.Type type = Type.OpenBadgeCredential;
 				for(Probe<JsonNode> probe : List.of(new ContextPropertyProbe(type), new TypePropertyProbe(type))) {					
@@ -110,6 +109,8 @@ public class OB30Inspector extends VCInspector {
 					if(broken(accumulator)) return abort(ctx, accumulator, probeCount);
 				}
 				
+				accumulator.add(new CredentialSubjectProbe().run(crd.getJson(), ctx));
+				
 				//signatures, proofs
 				probeCount++;
 				if(crd.getJwt().isPresent()){
diff --git a/inspector-vc/src/main/java/org/oneedtech/inspect/vc/probe/CredentialSubjectProbe.java b/inspector-vc/src/main/java/org/oneedtech/inspect/vc/probe/CredentialSubjectProbe.java
new file mode 100644
index 0000000..2932563
--- /dev/null
+++ b/inspector-vc/src/main/java/org/oneedtech/inspect/vc/probe/CredentialSubjectProbe.java
@@ -0,0 +1,42 @@
+package org.oneedtech.inspect.vc.probe;
+
+import org.oneedtech.inspect.core.probe.Probe;
+import org.oneedtech.inspect.core.probe.RunContext;
+import org.oneedtech.inspect.core.report.ReportItems;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.node.ArrayNode;
+
+/**
+ * A Probe that checks credential subject specifics not capturable by schemata.
+ * 
+ * @author mgylling
+ */
+public class CredentialSubjectProbe extends Probe<JsonNode> {
+	
+	public CredentialSubjectProbe() {
+		super(ID);
+	}
+
+	@Override
+	public ReportItems run(JsonNode root, RunContext ctx) throws Exception {
+
+		JsonNode subject = root.get("credentialSubject");
+		if(subject == null) return notRun("no credentialSubject node found", ctx); //error reported by schema
+
+		/*
+		 * Check that we have either .id or .identifier populated 
+		 */
+		JsonNode id = root.get("id");
+		if (id != null && id.textValue().strip().length() > 0) return success(ctx);
+				
+		JsonNode identifier = root.get("identifier");		
+		if(identifier != null && identifier instanceof ArrayNode 
+				&& ((ArrayNode)identifier).size() > 0) return success(ctx);
+					
+		return error("no id in credentialSubject", ctx);
+				
+	}
+
+	public static final String ID = CredentialSubjectProbe.class.getSimpleName();
+}