add @context value check probe

inspector-vc/src/main/java/org/oneedtech/inspect/vc/OB30Inspector.java

@@ -30,6 +30,8 @@ import org.oneedtech.inspect.util.resource.ResourceType;
 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.ContextPropertyProbe;
 import org.oneedtech.inspect.vc.probe.CredentialParseProbe;
 import org.oneedtech.inspect.vc.probe.ExpirationVerifierProbe;
 import org.oneedtech.inspect.vc.probe.InlineJsonSchemaProbe;
@@ -90,14 +92,15 @@ public class OB30Inspector extends VCInspector {
 				//we expect the above to place a generated object in the context				
 				Credential crd = ctx.getGeneratedObject(Credential.ID);
 								
-				//TODO check context IRIs? the schema doesnt do this 
-				
 				//TODO new check: that subject @id or IdentityObject is available (at least one is the req)
 								
-				//type property
+				//context and type properties
-				probeCount++;
+				Credential.Type type = Type.OpenBadgeCredential;
-				accumulator.add(new TypePropertyProbe(OpenBadgeCredential).run(crd.getJson(), ctx));
+				for(Probe<JsonNode> probe : List.of(new ContextPropertyProbe(type), new TypePropertyProbe(type))) {					
-				if(broken(accumulator)) return abort(ctx, accumulator, probeCount);
+					probeCount++;
+					accumulator.add(probe.run(crd.getJson(), ctx));
+					if(broken(accumulator)) return abort(ctx, accumulator, probeCount);
+				}
 				
 				//canonical schema and inline schemata
 				SchemaKey schema = crd.getSchemaKey().orElseThrow();

inspector-vc/src/main/java/org/oneedtech/inspect/vc/probe/ContextPropertyProbe.java

@@ -0,0 +1,63 @@
+package org.oneedtech.inspect.vc.probe;
+
+import static org.oneedtech.inspect.util.code.Defensives.checkNotNull;
+
+import java.util.List;
+import java.util.Map;
+
+import org.oneedtech.inspect.core.probe.Probe;
+import org.oneedtech.inspect.core.probe.RunContext;
+import org.oneedtech.inspect.core.report.ReportItems;
+import org.oneedtech.inspect.vc.Credential;
+import org.oneedtech.inspect.vc.util.JsonNodeUtil;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.node.ArrayNode;
+import com.google.common.collect.ImmutableMap;
+
+/**
+ * A Probe that verifies a credential's context property.
+ * 
+ * @author mgylling
+ */
+public class ContextPropertyProbe extends Probe<JsonNode> {
+	private final Credential.Type type;
+
+	public ContextPropertyProbe(Credential.Type type) {
+		super(ID);
+		this.type = checkNotNull(type);
+	}
+
+	@Override
+	public ReportItems run(JsonNode root, RunContext ctx) throws Exception {
+
+		ArrayNode contextNode = (ArrayNode) root.get("@context");
+		if (contextNode == null) {
+			return fatal("No @context property", ctx);	
+		}
+			
+		List<String> expected = values.get(type);
+		if(expected == null) {
+			return fatal(type.name() + " not recognized", ctx);
+		}
+		
+		List<String> given = JsonNodeUtil.asStringList(contextNode);
+		int pos = 0;
+		for(String uri : expected) {
+			if((given.size() < pos+1) || !given.get(pos).equals(uri)) {
+				return error("missing required @context uri " + uri + " at position " + (pos+1), ctx);	
+			}
+			pos++;
+		}
+				
+		return success(ctx);
+	}
+
+	private final static Map<Credential.Type, List<String>> values = new ImmutableMap.Builder<Credential.Type, List<String>>()
+	           .put(Credential.Type.OpenBadgeCredential, 
+	        		   List.of("https://www.w3.org/2018/credentials/v1", 
+	        				   "https://imsglobal.github.io/openbadges-specification/context.json")) //TODO will change (https://purl.imsglobal.org/spec/ob/v3p0/context/ob_v3p0.jsonld)
+	           .build();
+	
+	public static final String ID = ContextPropertyProbe.class.getSimpleName();
+}

inspector-vc/src/test/java/org/oneedtech/inspect/vc/OB30Tests.java

@@ -10,6 +10,7 @@ import org.oneedtech.inspect.core.Inspector.Behavior;
 import org.oneedtech.inspect.core.probe.json.JsonSchemaProbe;
 import org.oneedtech.inspect.core.report.Report;
 import org.oneedtech.inspect.test.PrintHelper;
+import org.oneedtech.inspect.vc.probe.ContextPropertyProbe;
 import org.oneedtech.inspect.vc.probe.ExpirationVerifierProbe;
 import org.oneedtech.inspect.vc.probe.InlineJsonSchemaProbe;
 import org.oneedtech.inspect.vc.probe.IssuanceVerifierProbe;
@@ -109,6 +110,17 @@ public class OB30Tests {
 		});	
 	}
 	
+	@Test
+	void testSimpleJsonContextError() {	
+		//removed one of the reqd context uris
+		assertDoesNotThrow(()->{
+			Report report = validator.run(Samples.OB30.JSON.SIMPLE_JSON_ERR_CONTEXT.asFileResource());
+			if(verbose) PrintHelper.print(report, true);
+			assertInvalid(report);
+			assertHasProbeID(report, ContextPropertyProbe.ID, true);
+		});	
+	}
+	
 	@Test
 	void testSimpleJsonSchemaError() throws Exception {
 		//issuer removed

inspector-vc/src/test/java/org/oneedtech/inspect/vc/Samples.java

@@ -17,6 +17,7 @@ public class Samples {
 			public final static Sample SIMPLE_JSON_EXPIRED = new Sample("ob30/simple-err-expired.json", false);
 			public final static Sample SIMPLE_JSON_ISSUED = new Sample("ob30/simple-err-issued.json", false);
 			public final static Sample SIMPLE_JSON_ISSUER = new Sample("ob30/simple-err-issuer.json", false);
+			public final static Sample SIMPLE_JSON_ERR_CONTEXT = new Sample("ob30/simple-err-context.json", false);
 		}
 		public static final class PNG {			
 			public final static Sample SIMPLE_JWT_PNG = new Sample("ob30/simple-jwt.png", true);

inspector-vc/src/test/resources/ob30/simple-err-context.json

@@ -0,0 +1,35 @@
+{
+  "@context": [
+    "https://imsglobal.github.io/openbadges-specification/context.json",
+    "https://w3id.org/security/suites/ed25519-2020/v1"
+  ],
+  "id": "http://example.edu/credentials/3732",
+  "type": [
+    "VerifiableCredential",
+    "OpenBadgeCredential"
+  ],
+  "issuer": {
+    "id": "https://example.edu/issuers/565049",
+    "type": [
+      "Profile"
+    ],
+    "name": "Example University"
+  },
+  "issuanceDate": "2010-01-01T00:00:00Z",
+  "name": "Example University Degree",
+  "credentialSubject": {
+    "id": "did:example:ebfeb1f712ebc6f1c276e12ec21",
+    "type": [
+      "AchievementSubject"
+    ]
+  },
+  "proof": [
+    {
+      "type": "Ed25519Signature2020",
+      "created": "2022-06-28T16:28:36Z",
+      "verificationMethod": "did:key:z6MkkUD3J14nkYzn46QeuaVSnp7dF85QJKwKvJvfsjx79aXj",
+      "proofPurpose": "assertionMethod",
+      "proofValue": "z3MUt2ZuU8Byqivxh6GphEM65AFYyNaGYibm97xLTafM7uGufZQLKvJR8itZwxKskvtFM3CUty46v26DZidMNoQnM"
+    }
+  ]
+}