8355779: When no "signature_algorithms_cert" extension is present we do not apply certificate scope constraints to algorithms in "signature_algorithms" extension

Backport-of: 34807df7627b067f750578987c941213a5f8336a

Author: GoeLin

src/java.base/share/classes/sun/security/ssl/SignatureAlgorithmsExtension.java

@@ -25,6 +25,7 @@
 
 package sun.security.ssl;
 
+import static sun.security.ssl.SignatureScheme.CERTIFICATE_SCOPE;
 import static sun.security.ssl.SignatureScheme.HANDSHAKE_SCOPE;
 
 import java.io.IOException;
@@ -33,6 +34,7 @@
 import java.util.Arrays;
 import java.util.List;
 import java.util.Locale;
+import javax.net.ssl.SSLException;
 import javax.net.ssl.SSLProtocolException;
 import sun.security.ssl.SSLExtension.ExtensionConsumer;
 import sun.security.ssl.SSLExtension.SSLExtensionSpec;
@@ -276,30 +278,8 @@ public void consume(ConnectionContext context,
                 return;
             }
 
-            // update the context
-            List<SignatureScheme> sss =
-                    SignatureScheme.getSupportedAlgorithms(
-                            shc.sslConfig,
-                            shc.algorithmConstraints, shc.negotiatedProtocol,
-                            spec.signatureSchemes,
-                            HANDSHAKE_SCOPE);
-
-            if (sss == null || sss.isEmpty()) {
-                throw shc.conContext.fatal(Alert.HANDSHAKE_FAILURE,
-                        "No supported signature algorithm");
-            }
-            shc.peerRequestedSignatureSchemes = sss;
-
-            // If no "signature_algorithms_cert" extension is present, then
-            // the "signature_algorithms" extension also applies to
-            // signatures appearing in certificates.
-            SignatureSchemesSpec certSpec =
-                    (SignatureSchemesSpec)shc.handshakeExtensions.get(
-                            SSLExtension.CH_SIGNATURE_ALGORITHMS_CERT);
-            if (certSpec == null) {
-                shc.peerRequestedCertSignSchemes = sss;
-                shc.handshakeSession.setPeerSupportedSignatureAlgorithms(sss);
-            }
+            updateHandshakeContext(shc, spec.signatureSchemes,
+                    SSLExtension.CH_SIGNATURE_ALGORITHMS_CERT);
 
             if (!shc.isResumption &&
                     shc.negotiatedProtocol.useTLS13PlusSpec()) {
@@ -507,30 +487,8 @@ public void consume(ConnectionContext context,
                 return;
             }
 
-            // update the context
-            List<SignatureScheme> sss =
-                    SignatureScheme.getSupportedAlgorithms(
-                            chc.sslConfig,
-                            chc.algorithmConstraints, chc.negotiatedProtocol,
-                            spec.signatureSchemes,
-                            HANDSHAKE_SCOPE);
-
-            if (sss == null || sss.isEmpty()) {
-                throw chc.conContext.fatal(Alert.HANDSHAKE_FAILURE,
-                        "No supported signature algorithm");
-            }
-            chc.peerRequestedSignatureSchemes = sss;
-
-            // If no "signature_algorithms_cert" extension is present, then
-            // the "signature_algorithms" extension also applies to
-            // signatures appearing in certificates.
-            SignatureSchemesSpec certSpec =
-                    (SignatureSchemesSpec)chc.handshakeExtensions.get(
-                            SSLExtension.CR_SIGNATURE_ALGORITHMS_CERT);
-            if (certSpec == null) {
-                chc.peerRequestedCertSignSchemes = sss;
-                chc.handshakeSession.setPeerSupportedSignatureAlgorithms(sss);
-            }
+            updateHandshakeContext(chc, spec.signatureSchemes,
+                    SSLExtension.CR_SIGNATURE_ALGORITHMS_CERT);
         }
     }
 
@@ -553,4 +511,49 @@ public void absent(ConnectionContext context,
                     "received CertificateRequest handshake message");
         }
     }
+
+    // Updates given HandshakeContext with peer signature schemes.
+    private static void updateHandshakeContext(HandshakeContext hc,
+            int[] signatureSchemes, SSLExtension signatureAlgorithmsCertExt)
+            throws SSLException {
+        List<SignatureScheme> handshakeSS =
+                SignatureScheme.getSupportedAlgorithms(
+                        hc.sslConfig,
+                        hc.algorithmConstraints,
+                        hc.negotiatedProtocol,
+                        signatureSchemes,
+                        HANDSHAKE_SCOPE);
+
+        if (handshakeSS.isEmpty()) {
+            throw hc.conContext.fatal(Alert.HANDSHAKE_FAILURE,
+                    "No supported signature algorithm");
+        }
+
+        hc.peerRequestedSignatureSchemes = handshakeSS;
+
+        // If no "signature_algorithms_cert" extension is present, then
+        // the "signature_algorithms" extension also applies to
+        // signatures appearing in certificates.
+        SignatureSchemesSpec certSpec =
+                (SignatureSchemesSpec) hc.handshakeExtensions.get(
+                        signatureAlgorithmsCertExt);
+
+        if (certSpec == null) {
+            List<SignatureScheme> certSS =
+                    SignatureScheme.getSupportedAlgorithms(
+                            hc.sslConfig,
+                            hc.algorithmConstraints,
+                            hc.negotiatedProtocol,
+                            signatureSchemes,
+                            CERTIFICATE_SCOPE);
+
+            if (certSS.isEmpty()) {
+                throw hc.conContext.fatal(Alert.HANDSHAKE_FAILURE,
+                        "No supported signature algorithm");
+            }
+
+            hc.peerRequestedCertSignSchemes = certSS;
+            hc.handshakeSession.setPeerSupportedSignatureAlgorithms(certSS);
+        }
+    }
 }