Breaking apart the PSK creation to an interface

Netflix · May 21, 2024 · e906fb9 · e906fb9
1 parent 29124da
commit e906fb9
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Showing 5 changed files with 68 additions and 7 deletions.
diff --git a/build.gradle b/build.gradle
@@ -86,7 +86,8 @@ subprojects {
                 mockito: 'org.mockito:mockito-core:5.+',
                 slf4j: "org.slf4j:slf4j-api:1.7.36",
                 truth: 'com.google.truth:truth:1.1.5',
-                awaitility: 'org.awaitility:awaitility:4.2.0'
+                awaitility: 'org.awaitility:awaitility:4.2.0',
+                lombok: 'org.projectlombok:lombok:1.18.30'
         ]
     }
 

diff --git a/zuul-core/build.gradle b/zuul-core/build.gradle
@@ -3,6 +3,9 @@ apply plugin: "java-library"
 
 dependencies {
 
+    compileOnly libraries.lombok
+    annotationProcessor(libraries.lombok)
+
     implementation libraries.guava
     // TODO(carl-mastrangelo): this can be implementation; remove Logger from public api points.
     api libraries.slf4j

diff --git a/zuul-core/src/main/java/com/netflix/zuul/netty/server/psk/ExternalTlsPskProvider.java b/zuul-core/src/main/java/com/netflix/zuul/netty/server/psk/ExternalTlsPskProvider.java
@@ -16,10 +16,6 @@
 
 package com.netflix.zuul.netty.server.psk;
 
-import org.bouncycastle.tls.TlsPSKExternal;
-
-import java.util.Vector;
-
 public interface ExternalTlsPskProvider {
-    TlsPSKExternal provide(Vector clientPskIdentities);
+    byte[] provide(byte[] clientPskIdentity, byte[] clientRandom) throws PskCreationFailureException;
 }
diff --git a/zuul-core/src/main/java/com/netflix/zuul/netty/server/psk/PskCreationFailureException.java b/zuul-core/src/main/java/com/netflix/zuul/netty/server/psk/PskCreationFailureException.java
@@ -0,0 +1,31 @@
+package com.netflix.zuul.netty.server.psk;
+
+public class PskCreationFailureException extends Exception {
+
+    public enum TlsAlertMessage {
+        /**
+         * The server does not recognize the (client) PSK identity
+         */
+        unknown_psk_identity,
+        /**
+         * The (client) PSK identity existed but the key was incorrect
+         */
+        decrypt_error,
+    }
+
+    private final TlsAlertMessage tlsAlertMessage;
+
+    public PskCreationFailureException(TlsAlertMessage tlsAlertMessage, String message) {
+        super(message);
+        this.tlsAlertMessage = tlsAlertMessage;
+    }
+
+    public PskCreationFailureException(TlsAlertMessage tlsAlertMessage, String message, Throwable cause) {
+        super(message, cause);
+        this.tlsAlertMessage = tlsAlertMessage;
+    }
+
+    public TlsAlertMessage getTlsAlertMessage() {
+        return tlsAlertMessage;
+    }
+}
diff --git a/zuul-core/src/main/java/com/netflix/zuul/netty/server/psk/TlsPskHandler.java b/zuul-core/src/main/java/com/netflix/zuul/netty/server/psk/TlsPskHandler.java
@@ -28,18 +28,23 @@
 import io.netty.handler.codec.ByteToMessageDecoder;
 import io.netty.handler.ssl.SslHandshakeCompletionEvent;
 import io.netty.util.ReferenceCountUtil;
+import lombok.SneakyThrows;
 import org.bouncycastle.tls.AbstractTlsServer;
 import org.bouncycastle.tls.AlertDescription;
 import org.bouncycastle.tls.AlertLevel;
+import org.bouncycastle.tls.BasicTlsPSKExternal;
 import org.bouncycastle.tls.CipherSuite;
+import org.bouncycastle.tls.PRFAlgorithm;
 import org.bouncycastle.tls.ProtocolName;
 import org.bouncycastle.tls.ProtocolVersion;
+import org.bouncycastle.tls.PskIdentity;
 import org.bouncycastle.tls.TlsCredentials;
 import org.bouncycastle.tls.TlsFatalAlert;
 import org.bouncycastle.tls.TlsPSKExternal;
 import org.bouncycastle.tls.TlsServerProtocol;
 import org.bouncycastle.tls.TlsUtils;
 import org.bouncycastle.tls.crypto.TlsCrypto;
+import org.bouncycastle.tls.crypto.TlsSecret;
 import org.bouncycastle.tls.crypto.impl.jcajce.JcaTlsCryptoProvider;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -291,8 +296,21 @@ public ProtocolVersion getServerVersion() throws IOException {
         }
 
         @Override
+        @SneakyThrows // TODO: Ask BC folks to see if getExternalPSK can throw a checked exception
         public TlsPSKExternal getExternalPSK(Vector clientPskIdentities) {
-            return externalTlsPskProvider.provide(clientPskIdentities);
+            byte[] clientPskIdentity = ((PskIdentity)clientPskIdentities.get(0)).getIdentity();
+            byte[] psk;
+            try{
+                psk = externalTlsPskProvider.provide(clientPskIdentity, this.context.getSecurityParametersHandshake().getClientRandom());
+            }catch (PskCreationFailureException e) {
+                throw switch (e.getTlsAlertMessage()) {
+                    case unknown_psk_identity -> new TlsFatalAlert(AlertDescription.unknown_psk_identity, "Unknown or null client PSk identity");
+                    case decrypt_error -> new TlsFatalAlert(AlertDescription.decrypt_error, "Invalid or expired client PSk identity");
+                };
+            }
+            TlsSecret pskTlsSecret = getCrypto().createSecret(psk);
+            int prfAlgorithm = getPRFAlgorithm13(getSelectedCipherSuite());
+            return new BasicTlsPSKExternal(clientPskIdentity, pskTlsSecret, prfAlgorithm);
         }
 
         @Override
@@ -348,6 +366,18 @@ public String getApplicationProtocol() {
             }
             return null;
         }
+
+        private static int getPRFAlgorithm13(int cipherSuite) {
+            return switch (cipherSuite) {
+                case CipherSuite.TLS_AES_128_CCM_SHA256,
+                        CipherSuite.TLS_AES_128_CCM_8_SHA256,
+                        CipherSuite.TLS_AES_128_GCM_SHA256,
+                        CipherSuite.TLS_CHACHA20_POLY1305_SHA256 -> PRFAlgorithm.tls13_hkdf_sha256;
+                case CipherSuite.TLS_AES_256_GCM_SHA384 -> PRFAlgorithm.tls13_hkdf_sha384;
+                case CipherSuite.TLS_SM4_CCM_SM3, CipherSuite.TLS_SM4_GCM_SM3 -> PRFAlgorithm.tls13_hkdf_sm3;
+                default -> -1;
+            };
+        }
     }
 
     static class TlsPskServerProtocol extends TlsServerProtocol {