SHA256 / Base64 fingerprint now used to print certificates on ui

Author: thsc42

src/main/java/net/sharksystem/asap/ASAPEncounterManagerImpl.java

@@ -48,7 +48,8 @@ public class ASAPEncounterManagerImpl implements ASAPEncounterManager, ASAPEncou
     /** remember remote address of peers (they can have more than one): peerID -> remote address */
     private Map<CharSequence, Set<CharSequence>> peerRemoteAddresses = new HashMap<>();
 
-    public ASAPEncounterManagerImpl(ASAPConnectionHandler asapConnectionHandler, CharSequence peerID) throws SharkException, IOException {
+    public ASAPEncounterManagerImpl(ASAPConnectionHandler asapConnectionHandler, CharSequence peerID)
+            throws SharkException, IOException {
         this(asapConnectionHandler, peerID, DEFAULT_WAIT_BEFORE_RECONNECT_TIME);
     }
 

src/main/java/net/sharksystem/asap/crypto/ASAPCryptoAlgorithms.java

@@ -8,6 +8,7 @@
 import javax.crypto.spec.SecretKeySpec;
 import java.io.*;
 import java.security.*;
+import java.util.Base64;
 
 public class ASAPCryptoAlgorithms {
     /**
@@ -250,4 +251,17 @@ public static boolean verify(byte[] signedData, byte[] signatureBytes, String se
             throw new ASAPSecurityException("verifying failed: " + ASAPKeyStore.getAsymmetricSigningAlgorithm(), e);
         }
     }
+
+    /**
+     * Produces a Base 64 fingerprint with SHA256.
+     * This fingerprint is not necessarily identical to others.
+     * It an ASAP standard, though.
+     * @param publicKey
+     * @return
+     */
+    public static String getFingerprint(PublicKey publicKey) throws NoSuchAlgorithmException {
+        MessageDigest digest = MessageDigest.getInstance("SHA-256");
+        byte[] result = digest.digest(publicKey.getEncoded());
+        return Base64.getEncoder().encodeToString(result);
+    }
 }

src/test/java/net/sharksystem/asap/crypto/CryptoUsage.java

@@ -7,6 +7,7 @@
 import org.junit.Test;
 
 import java.io.IOException;
+import java.security.NoSuchAlgorithmException;
 
 import static net.sharksystem.utils.testsupport.TestConstants.ALICE_ID;
 import static net.sharksystem.utils.testsupport.TestConstants.BOB_ID;
@@ -25,6 +26,12 @@ public void setupASAPKeyStores() throws ASAPSecurityException {
         this.bobKeyStorage.addKeyPair(ALICE_ID, aliceKeyStorage.getKeyPair());
     }
 
+    @Test
+    public void printFingerprint() throws ASAPSecurityException, NoSuchAlgorithmException {
+        System.out.println(ASAPCryptoAlgorithms.getFingerprint(aliceKeyStorage.getPublicKey()));
+    }
+
+
     @Test
     public void signVerifyUsage() throws ASAPSecurityException {
         String messageString = "From Alice signed";