Make CertificateUtils to use other key algorithms (#8609)

core/src/main/java/io/grpc/util/CertificateUtils.java

@@ -56,7 +56,8 @@ public final class CertificateUtils {
 
   /**
    * Generates a {@link PrivateKey} from a PEM file.
-   * The key should be PKCS #8 formatted.
+   * The key should be PKCS #8 formatted. The key algorithm should be "RSA", "DiffieHellman",
+   * "DSA", or "EC".
    * The PEM file should contain one item in Base64 encoding, with plain-text headers and footers
    * (e.g. -----BEGIN PRIVATE KEY----- and -----END PRIVATE KEY-----).
    *
@@ -80,9 +81,20 @@ public final class CertificateUtils {
       keyContent.append(line);
     }
     byte[] decodedKeyBytes = BaseEncoding.base64().decode(keyContent.toString());
-    KeyFactory keyFactory = KeyFactory.getInstance("RSA");
     PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(decodedKeyBytes);
-    return keyFactory.generatePrivate(keySpec);
+    try {
+      return KeyFactory.getInstance("RSA").generatePrivate(keySpec);
+    } catch (InvalidKeySpecException ignore) {
+      try {
+        return KeyFactory.getInstance("DSA").generatePrivate(keySpec);
+      } catch (InvalidKeySpecException ignore2) {
+        try {
+          return KeyFactory.getInstance("EC").generatePrivate(keySpec);
+        } catch (InvalidKeySpecException e) {
+          throw new InvalidKeySpecException("Neither RSA, DSA nor EC worked", e);
+        }
+      }
+    }
   }
 }
 

core/src/test/java/io/grpc/util/CertificateUtilsTest.java

@@ -43,6 +43,7 @@ public class CertificateUtilsTest {
   public static final String BAD_PEM_CONTENT = "----BEGIN PRIVATE KEY-----\n"
       + "MIIEvgIBADANBgkqhkiG9w0BAQEFAASCBKgwggSkAgEAAoIBAQDvdzKDTYvRgjBO\n"
       + "-----END PRIVATE KEY-----";
+  public static final String ECDSA_KEY_FILE = "ecdsa.key";
 
   @Test
   public void readPemCertFile() throws CertificateException, IOException {
@@ -101,4 +102,13 @@ public class CertificateUtilsTest {
     }
   }
 
+  @Test
+  public void readEcdsaKeyFile() throws Exception {
+    InputStream in = TestUtils.class.getResourceAsStream("/certs/" + ECDSA_KEY_FILE);
+    PrivateKey key = CertificateUtils.getPrivateKey(in);
+    // Checks some information on the test key.
+    assertThat(key.getAlgorithm()).isEqualTo("EC");
+    assertThat(key.getFormat()).isEqualTo("PKCS#8");
+  }
+
 }

testing/src/main/resources/certs/README

@@ -62,6 +62,11 @@ common name which is set to *.test.google.com.
 $ openssl x509 -req -CA ca.pem -CAkey ca.key -CAcreateserial -in server1.csr \
   -out server1.pem -extensions req_ext -extfile server1-openssl.cnf -days 3650
 
+ecdsa.key is used to test keys with algorithm other than RSA:
+----------------------------------------------------------------------------
+$ openssl ecparam -name secp256k1 -genkey -noout -out ecdsa.pem
+$ openssl pkcs8 -topk8 -in ecdsa.pem -out ecdsa.key -nocrypt
+
 Clean up:
 ---------
 $ rm *.rsa

testing/src/main/resources/certs/ecdsa.key

@@ -0,0 +1,5 @@
+-----BEGIN PRIVATE KEY-----
+MIGEAgEAMBAGByqGSM49AgEGBSuBBAAKBG0wawIBAQQgS0hDYghCuDnBobsToMW6
+vGqwulbAGUX8Oku4ysWMa4qhRANCAAThAMij1tkl4/7RQpZg3w7z1McGSS9q01+4
+3bDcF/Ge2gATx/SNYT5TqaSx7Rka/sJAGaX47ExWLca4gz9KGHih
+-----END PRIVATE KEY-----