Examples with EncryptionHeader org.apache.poi.poifs.crypt.EncryptionHeader used on opensource projects

Example 1 with EncryptionHeader

use of org.apache.poi.poifs.crypt.EncryptionHeader in project poi by apache.

the class StandardDecryptor method getCipher.

private Cipher getCipher(SecretKey key) {
    EncryptionHeader em = getEncryptionInfo().getHeader();
    ChainingMode cm = em.getChainingMode();
    assert (cm == ChainingMode.ecb);
    return CryptoFunctions.getCipher(key, em.getCipherAlgorithm(), cm, null, Cipher.DECRYPT_MODE);
}

Example 2 with EncryptionHeader

use of org.apache.poi.poifs.crypt.EncryptionHeader in project poi by apache.

the class AgileDecryptor method initCipherForBlock.

protected static Cipher initCipherForBlock(Cipher existing, int block, boolean lastChunk, EncryptionInfo encryptionInfo, SecretKey skey, int encryptionMode) throws GeneralSecurityException {
    EncryptionHeader header = encryptionInfo.getHeader();
    String padding = (lastChunk ? "PKCS5Padding" : "NoPadding");
    if (existing == null || !existing.getAlgorithm().endsWith(padding)) {
        existing = getCipher(skey, header.getCipherAlgorithm(), header.getChainingMode(), header.getKeySalt(), encryptionMode, padding);
    }
    byte[] blockKey = new byte[4];
    LittleEndian.putInt(blockKey, 0, block);
    byte[] iv = generateIv(header.getHashAlgorithm(), header.getKeySalt(), blockKey, header.getBlockSize());
    AlgorithmParameterSpec aps;
    if (header.getCipherAlgorithm() == CipherAlgorithm.rc2) {
        aps = new RC2ParameterSpec(skey.getEncoded().length * 8, iv);
    } else {
        aps = new IvParameterSpec(iv);
    }
    existing.init(encryptionMode, skey, aps);
    return existing;
}

Example 3 with EncryptionHeader

use of org.apache.poi.poifs.crypt.EncryptionHeader in project poi by apache.

the class CryptoAPIDecryptor method initCipherForBlock.

protected static Cipher initCipherForBlock(Cipher cipher, int block, EncryptionInfo encryptionInfo, SecretKey skey, int encryptMode) throws GeneralSecurityException {
    EncryptionVerifier ver = encryptionInfo.getVerifier();
    HashAlgorithm hashAlgo = ver.getHashAlgorithm();
    byte[] blockKey = new byte[4];
    LittleEndian.putUInt(blockKey, 0, block);
    MessageDigest hashAlg = CryptoFunctions.getMessageDigest(hashAlgo);
    hashAlg.update(skey.getEncoded());
    byte[] encKey = hashAlg.digest(blockKey);
    EncryptionHeader header = encryptionInfo.getHeader();
    int keyBits = header.getKeySize();
    encKey = CryptoFunctions.getBlock0(encKey, keyBits / 8);
    if (keyBits == 40) {
        encKey = CryptoFunctions.getBlock0(encKey, 16);
    }
    SecretKey key = new SecretKeySpec(encKey, skey.getAlgorithm());
    if (cipher == null) {
        cipher = CryptoFunctions.getCipher(key, header.getCipherAlgorithm(), null, null, encryptMode);
    } else {
        cipher.init(encryptMode, key);
    }
    return cipher;
}