fix #473: ROT13 on String or Spannable, including new test

1 files changed, 113 insertions, 0 deletions

diff --git a/main/src/cgeo/geocaching/utils/CryptUtils.java b/main/src/cgeo/geocaching/utils/CryptUtils.java
new file mode 100644
index 0000000..a2927aa
--- /dev/null
+++ b/main/src/cgeo/geocaching/utils/CryptUtils.java
@@ -0,0 +1,113 @@
+package cgeo.geocaching.utils;
+
+import cgeo.geocaching.cgSettings;
+
+import android.text.Spannable;
+import android.text.SpannableStringBuilder;
+import android.util.Log;
+
+import java.math.BigInteger;
+import java.security.MessageDigest;
+
+import javax.crypto.Mac;
+import javax.crypto.spec.SecretKeySpec;
+
+public final class CryptUtils {
+    public static String rot13(String text) {
+        if (text == null) {
+            return "";
+        }
+        final StringBuilder result = new StringBuilder();
+        // plaintext flag (do not convert)
+        boolean plaintext = false;
+
+        final int length = text.length();
+        int c;
+        int capitalized;
+        for (int index = 0; index < length; index++) {
+            c = text.charAt(index);
+            if (c == '[') {
+                plaintext = true;
+            } else if (c == ']') {
+                plaintext = false;
+            } else if (!plaintext) {
+                capitalized = c & 32;
+                c &= ~capitalized;
+                c = ((c >= 'A') && (c <= 'Z') ? ((c - 'A' + 13) % 26 + 'A') : c)
+                        | capitalized;
+            }
+            result.append((char) c);
+        }
+        return result.toString();
+    }
+
+    public static String md5(String text) {
+        String hashed = "";
+
+        try {
+            final MessageDigest digest = MessageDigest.getInstance("MD5");
+            digest.update(text.getBytes(), 0, text.length());
+            hashed = new BigInteger(1, digest.digest()).toString(16);
+        } catch (Exception e) {
+            Log.e(cgSettings.tag, "cgBase.md5: " + e.toString());
+        }
+
+        return hashed;
+    }
+
+    public static String sha1(String text) {
+        String hashed = "";
+
+        try {
+            final MessageDigest digest = MessageDigest.getInstance("SHA-1");
+            digest.update(text.getBytes(), 0, text.length());
+            hashed = new BigInteger(1, digest.digest()).toString(16);
+        } catch (Exception e) {
+            Log.e(cgSettings.tag, "cgBase.sha1: " + e.toString());
+        }
+
+        return hashed;
+    }
+
+    public static byte[] hashHmac(String text, String salt) {
+        byte[] macBytes = {};
+
+        try {
+            final SecretKeySpec secretKeySpec = new SecretKeySpec(salt.getBytes(), "HmacSHA1");
+            final Mac mac = Mac.getInstance("HmacSHA1");
+            mac.init(secretKeySpec);
+            macBytes = mac.doFinal(text.getBytes());
+        } catch (Exception e) {
+            Log.e(cgSettings.tag, "cgBase.hashHmac: " + e.toString());
+        }
+
+        return macBytes;
+    }
+
+    public static CharSequence rot13(final Spannable span) {
+        // I needed to re-implement the rot13(String) encryption here because we must work on
+        // a SpannableStringBuilder instead of the pure text and we must replace each character inline.
+        // Otherwise we loose all the images, colors and so on...
+        final SpannableStringBuilder buffer = new SpannableStringBuilder(span);
+        boolean plaintext = false;
+
+        final int length = span.length();
+        int c;
+        int capitalized;
+        for (int index = 0; index < length; index++) {
+            c = span.charAt(index);
+            if (c == '[') {
+                plaintext = true;
+            } else if (c == ']') {
+                plaintext = false;
+            } else if (!plaintext) {
+                capitalized = c & 32;
+                c &= ~capitalized;
+                c = ((c >= 'A') && (c <= 'Z') ? ((c - 'A' + 13) % 26 + 'A') : c)
+                        | capitalized;
+            }
+            buffer.replace(index, index + 1, String.valueOf((char) c));
+        }
+        return buffer;
+    }
+}