protected void engineSetMode(String mode) {
String modeName = Strings.toUpperCase(mode);
if (modeName.equals("ECB")) {
ivLength = 0;
cipher = new PaddedBufferedBlockCipher(cipher.getUnderlyingCipher());
} else if (modeName.equals("CBC")) {
ivLength = cipher.getUnderlyingCipher().getBlockSize();
cipher = new PaddedBufferedBlockCipher(new CBCBlockCipher(cipher.getUnderlyingCipher()));
} else if (modeName.startsWith("OFB")) {
ivLength = cipher.getUnderlyingCipher().getBlockSize();
if (modeName.length() != 3) {
int wordSize = Integer.parseInt(modeName.substring(3));
cipher =
new PaddedBufferedBlockCipher(
new OFBBlockCipher(cipher.getUnderlyingCipher(), wordSize));
} else {
cipher =
new PaddedBufferedBlockCipher(
new OFBBlockCipher(cipher.getUnderlyingCipher(), 8 * cipher.getBlockSize()));
}
} else if (modeName.startsWith("CFB")) {
ivLength = cipher.getUnderlyingCipher().getBlockSize();
if (modeName.length() != 3) {
int wordSize = Integer.parseInt(modeName.substring(3));
cipher =
new PaddedBufferedBlockCipher(
new CFBBlockCipher(cipher.getUnderlyingCipher(), wordSize));
} else {
cipher =
new PaddedBufferedBlockCipher(
new CFBBlockCipher(cipher.getUnderlyingCipher(), 8 * cipher.getBlockSize()));
}
} else {
throw new IllegalArgumentException("can't support mode " + mode);
}
}
protected int engineGetBlockSize() {
return cipher.getBlockSize();
}