static apr_status_t crypto_cipher_mechanism()

in crypto/apr_crypto_commoncrypto.c [337:433]

• 76 lines of code
• 11 McCabe index (conditional complexity)

static apr_status_t crypto_cipher_mechanism(apr_crypto_key_t *key,
        const apr_crypto_block_key_type_e type,
        const apr_crypto_block_key_mode_e mode, const int doPad, apr_pool_t *p)
{
    /* handle padding */
    key->options = doPad ? kCCOptionPKCS7Padding : 0;

    /* determine the algorithm to be used */
    switch (type) {

    case (APR_KEY_3DES_192):

        /* A 3DES key */
        if (mode == APR_MODE_CBC) {
            key->algorithm = kCCAlgorithm3DES;
            key->keyLen = kCCKeySize3DES;
            key->ivSize = kCCBlockSize3DES;
            key->blockSize = kCCBlockSize3DES;
        }
        else {
            key->algorithm = kCCAlgorithm3DES;
            key->options += kCCOptionECBMode;
            key->keyLen = kCCKeySize3DES;
            key->ivSize = 0;
            key->blockSize = kCCBlockSize3DES;
        }
        break;

    case (APR_KEY_AES_128):

        if (mode == APR_MODE_CBC) {
            key->algorithm = kCCAlgorithmAES128;
            key->keyLen = kCCKeySizeAES128;
            key->ivSize = kCCBlockSizeAES128;
            key->blockSize = kCCBlockSizeAES128;
        }
        else {
            key->algorithm = kCCAlgorithmAES128;
            key->options += kCCOptionECBMode;
            key->keyLen = kCCKeySizeAES128;
            key->ivSize = 0;
            key->blockSize = kCCBlockSizeAES128;
        }
        break;

    case (APR_KEY_AES_192):

        if (mode == APR_MODE_CBC) {
            key->algorithm = kCCAlgorithmAES128;
            key->keyLen = kCCKeySizeAES192;
            key->ivSize = kCCBlockSizeAES128;
            key->blockSize = kCCBlockSizeAES128;
        }
        else {
            key->algorithm = kCCAlgorithmAES128;
            key->options += kCCOptionECBMode;
            key->keyLen = kCCKeySizeAES192;
            key->ivSize = 0;
            key->blockSize = kCCBlockSizeAES128;
        }
        break;

    case (APR_KEY_AES_256):

        if (mode == APR_MODE_CBC) {
            key->algorithm = kCCAlgorithmAES128;
            key->keyLen = kCCKeySizeAES256;
            key->ivSize = kCCBlockSizeAES128;
            key->blockSize = kCCBlockSizeAES128;
        }
        else {
            key->algorithm = kCCAlgorithmAES128;
            key->options += kCCOptionECBMode;
            key->keyLen = kCCKeySizeAES256;
            key->ivSize = 0;
            key->blockSize = kCCBlockSizeAES128;
        }
        break;

    default:

        /* TODO: Support CAST, Blowfish */

        /* unknown key type, give up */
        return APR_EKEYTYPE;

    }

    /* make space for the key */
    key->key = apr_palloc(p, key->keyLen);
    if (!key->key) {
        return APR_ENOMEM;
    }
    apr_crypto_clear(p, key->key, key->keyLen);

    return APR_SUCCESS;
}