1 files changed, 95 insertions, 0 deletions
diff --git a/jdisc-security-filters/src/main/java/com/yahoo/jdisc/http/filter/security/athenz/AthenzPrincipalFilter.java b/jdisc-security-filters/src/main/java/com/yahoo/jdisc/http/filter/security/athenz/AthenzPrincipalFilter.java
new file mode 100644
index 00000000000..ad6c82138e1
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+++ b/jdisc-security-filters/src/main/java/com/yahoo/jdisc/http/filter/security/athenz/AthenzPrincipalFilter.java
@@ -0,0 +1,95 @@
+// Copyright 2018 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.jdisc.http.filter.security.athenz;
+
+import com.google.inject.Inject;
+import com.yahoo.jdisc.Response;
+import com.yahoo.jdisc.http.filter.DiscFilterRequest;
+import com.yahoo.jdisc.http.filter.security.cors.CorsFilterConfig;
+import com.yahoo.jdisc.http.filter.security.cors.CorsRequestFilterBase;
+import com.yahoo.vespa.athenz.api.AthenzPrincipal;
+import com.yahoo.vespa.athenz.api.NToken;
+import com.yahoo.vespa.athenz.utils.AthenzIdentities;
+import com.yahoo.vespa.athenz.utils.ntoken.NTokenValidator;
+
+import java.nio.file.Paths;
+import java.security.cert.X509Certificate;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Optional;
+import java.util.Set;
+
+
+/**
+ * Authenticates Athenz principal, either through:
+ *  1. TLS client authentication (based on Athenz x509 identity certficiate).
+ *  2. The principal token (NToken) header.
+ * The TLS authentication is based on the following assumptions:
+ *  - The underlying connector is configured with 'clientAuth' set to either WANT_AUTH or NEED_AUTH.
+ *  - The trust store is configured with the Athenz CA certificates only.
+ *
+ * @author bjorncs
+ */
+public class AthenzPrincipalFilter extends CorsRequestFilterBase {
+
+    private final NTokenValidator validator;
+    private final String principalTokenHeader;
+
+    @Inject
+    public AthenzPrincipalFilter(AthenzPrincipalFilterConfig athenzPrincipalFilterConfig, CorsFilterConfig corsConfig) {
+        this(new NTokenValidator(Paths.get(athenzPrincipalFilterConfig.athenzConfFile())),
+             athenzPrincipalFilterConfig.principalHeaderName(),
+             new HashSet<>(corsConfig.allowedUrls()));
+    }
+
+    AthenzPrincipalFilter(NTokenValidator validator,
+                          String principalTokenHeader,
+                          Set<String> corsAllowedUrls) {
+        super(corsAllowedUrls);
+        this.validator = validator;
+        this.principalTokenHeader = principalTokenHeader;
+    }
+
+    @Override
+    public Optional<ErrorResponse> filterRequest(DiscFilterRequest request) {
+        try {
+            Optional<AthenzPrincipal> certificatePrincipal = getClientCertificate(request)
+                    .map(AthenzIdentities::from)
+                    .map(AthenzPrincipal::new);
+            Optional<AthenzPrincipal> nTokenPrincipal = getPrincipalToken(request, principalTokenHeader)
+                    .map(validator::validate);
+
+            if (!certificatePrincipal.isPresent() && !nTokenPrincipal.isPresent()) {
+                String errorMessage = "Unable to authenticate Athenz identity. " +
+                        "Either client certificate or principal token is required.";
+                return Optional.of(new ErrorResponse(Response.Status.UNAUTHORIZED, errorMessage));
+            }
+            if (certificatePrincipal.isPresent() && nTokenPrincipal.isPresent()
+                    && !certificatePrincipal.get().getIdentity().equals(nTokenPrincipal.get().getIdentity())) {
+                String errorMessage = String.format(
+                        "Identity in principal token does not match x509 CN: token-identity=%s, cert-identity=%s",
+                        nTokenPrincipal.get().getIdentity().getFullName(),
+                        certificatePrincipal.get().getIdentity().getFullName());
+                return Optional.of(new ErrorResponse(Response.Status.UNAUTHORIZED, errorMessage));
+            }
+            AthenzPrincipal principal = nTokenPrincipal.orElseGet(certificatePrincipal::get);
+            request.setUserPrincipal(principal);
+            request.setRemoteUser(principal.getName());
+            return Optional.empty();
+        } catch (Exception e) {
+            return Optional.of(new ErrorResponse(Response.Status.UNAUTHORIZED, e.getMessage()));
+        }
+    }
+
+    private static Optional<X509Certificate> getClientCertificate(DiscFilterRequest request) {
+        List<X509Certificate> chain = request.getClientCertificateChain();
+        if (chain.isEmpty()) return Optional.empty();
+        return Optional.of(chain.get(0));
+    }
+
+    private static Optional<NToken> getPrincipalToken(DiscFilterRequest request, String principalTokenHeaderName) {
+        return Optional.ofNullable(request.getHeader(principalTokenHeaderName))
+                .filter(token -> !token.isEmpty())
+                .map(NToken::new);
+    }
+
+}