/**
* Does the actual work for decrypting - if version does not match current cipher then tries the
* previous cipher
*/
private Message decryptMessage(Cipher cipher, Message msg) throws Exception {
EncryptHeader hdr = (EncryptHeader) msg.getHeader(this.id);
if (!Arrays.equals(hdr.getVersion(), getSymVersion())) {
log.warn(
"attempting to use stored cipher as message does not use current encryption version ");
cipher = keyMap.get(new AsciiString(hdr.getVersion()));
if (cipher == null) {
log.warn("unable to find a matching cipher in previous key map");
return null;
}
log.trace("decrypting using previous cipher version");
synchronized (cipher) {
return _decrypt(cipher, msg, hdr.encryptEntireMessage());
}
}
return _decrypt(cipher, msg, hdr.encryptEntireMessage());
}
