1 files changed, 27 insertions, 3 deletions
diff --git a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/util/KeyFormattingUtils.java b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/util/KeyFormattingUtils.java
index 91a7d361a..0b80b5fe9 100644
--- a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/util/KeyFormattingUtils.java
+++ b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/util/KeyFormattingUtils.java
@@ -227,6 +227,14 @@ public class KeyFormattingUtils {
         return buf.getLong();
     }
 
+    public static int getShortKeyIdFromFingerprint(byte[] fingerprint) {
+        ByteBuffer buf = ByteBuffer.wrap(fingerprint);
+        // skip first 16 bytes of the fingerprint
+        buf.position(16);
+        // the last four bytes are the short key id (big endian, which is default order in ByteBuffer)
+        return buf.getInt();
+    }
+
     /**
      * Convert key id from long to 64 bit hex string
      * <p/>
@@ -238,16 +246,24 @@ public class KeyFormattingUtils {
      * @return
      */
     public static String convertKeyIdToHex(long keyId) {
+        return convertKeyIdToHex(keyId, true);
+    }
+
+    public static String convertKeyIdToHex(long keyId, boolean header) {
         long upper = keyId >> 32;
         if (upper == 0) {
             // this is a short key id
-            return convertKeyIdToHexShort(keyId);
+            return convertKeyIdToHexShort(keyId, header);
         }
-        return "0x" + convertKeyIdToHex32bit(keyId >> 32) + convertKeyIdToHex32bit(keyId);
+        return header?"0x":"" + convertKeyIdToHex32bit(keyId >> 32) + convertKeyIdToHex32bit(keyId);
     }
 
     public static String convertKeyIdToHexShort(long keyId) {
-        return "0x" + convertKeyIdToHex32bit(keyId);
+        return convertKeyIdToHexShort(keyId, true);
+    }
+
+    public static String convertKeyIdToHexShort(long keyId, boolean header) {
+        return header?"0x":"" + convertKeyIdToHex32bit(keyId);
     }
 
     private static String convertKeyIdToHex32bit(long keyId) {
@@ -258,6 +274,14 @@ public class KeyFormattingUtils {
         return hexString;
     }
 
+    public static String getKeyIdAsHexFromFingerprint(byte[] fingerprint, boolean header) {
+        return convertKeyIdToHex(getKeyIdFromFingerprint(fingerprint), header);
+    }
+
+    public static String getShortKeyIdAsHexFromFingerprint(byte[] fingerprint, boolean header) {
+        return convertKeyIdToHex(getShortKeyIdFromFingerprint(fingerprint), header);
+    }
+
     /**
      * Makes a human-readable version of a key ID, which is usually 64 bits: lower-case, no
      * leading 0x, space-separated quartets (for keys whose length in hex is divisible by 4)