diff options
Diffstat (limited to 'app/src/main/java/com/wireguard/android/widget/KeyInputFilter.java')
-rw-r--r-- | app/src/main/java/com/wireguard/android/widget/KeyInputFilter.java | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/app/src/main/java/com/wireguard/android/widget/KeyInputFilter.java b/app/src/main/java/com/wireguard/android/widget/KeyInputFilter.java new file mode 100644 index 00000000..45652ed5 --- /dev/null +++ b/app/src/main/java/com/wireguard/android/widget/KeyInputFilter.java @@ -0,0 +1,47 @@ +package com.wireguard.android.widget; + +import android.text.InputFilter; +import android.text.SpannableStringBuilder; +import android.text.Spanned; + +import com.wireguard.crypto.KeyEncoding; + +/** + * InputFilter for entering WireGuard private/public keys encoded with base64. + */ + +public class KeyInputFilter implements InputFilter { + public static KeyInputFilter newInstance() { + return new KeyInputFilter(); + } + + @Override + public CharSequence filter(final CharSequence source, + final int sStart, final int sEnd, + final Spanned dest, + final int dStart, final int dEnd) { + SpannableStringBuilder replacement = null; + int rIndex = 0; + final int dLength = dest.length(); + for (int sIndex = sStart; sIndex < sEnd; ++sIndex) { + final char c = source.charAt(sIndex); + final int dIndex = dStart + (sIndex - sStart); + // Restrict characters to the base64 character set. + // Ensure adding this character does not push the length over the limit. + if (((dIndex + 1 < KeyEncoding.KEY_LENGTH_BASE64 && isAllowed(c)) || + (dIndex + 1 == KeyEncoding.KEY_LENGTH_BASE64 && c == '=')) && + dLength + (sIndex - sStart) < KeyEncoding.KEY_LENGTH_BASE64) { + ++rIndex; + } else { + if (replacement == null) + replacement = new SpannableStringBuilder(source, sStart, sEnd); + replacement.delete(rIndex, rIndex + 1); + } + } + return replacement; + } + + private boolean isAllowed(final char c) { + return Character.isLetterOrDigit(c) || c == '+' || c == '/'; + } +} |