On Thu, Jan 21, 2016 at 03:51:37PM +0800, Fam Zheng wrote:
> On Wed, 01/20 17:38, Daniel P. Berrange wrote:
> > +static int qcrypto_ivgen_essiv_init(QCryptoIVGen *ivgen,
> > + const uint8_t *key, size_t nkey,
> > + Error **errp)
> > +{
> > + uint8_t *salt;
> > + size_t nhash;
> > + QCryptoIVGenESSIV *essiv = g_new0(QCryptoIVGenESSIV, 1);
> > +
> > + nhash = qcrypto_hash_digest_len(ivgen->hash);
> > + /* Salt must be larger of hash size or key size */
> > + salt = g_new0(uint8_t, nhash > nkey ? nhash : nkey);
> > +
> > + if (qcrypto_hash_bytes(ivgen->hash, (const gchar *)key, nkey,
> > + &salt, &nhash,
> > + errp) < 0) {
> > + g_free(essiv);
> > + return -1;
> > + }
> > +
> > + essiv->cipher = qcrypto_cipher_new(ivgen->cipher,
> > + QCRYPTO_CIPHER_MODE_ECB,
> > + salt, nkey,
> > + errp);
> > + if (!essiv->cipher) {
> > + g_free(essiv);
> > + g_free(salt);
> > + return -1;
> > + }
> > +
> > + g_free(salt);
> > + ivgen->private = essiv;
> > +
> > + return 0;
> > +}
> > +
> > +static int qcrypto_ivgen_essiv_calculate(QCryptoIVGen *ivgen,
> > + uint64_t sector,
> > + uint8_t *iv, size_t niv,
> > + Error **errp)
> > +{
> > + QCryptoIVGenESSIV *essiv = ivgen->private;
> > + size_t ndata = qcrypto_cipher_get_block_len(ivgen->cipher);
> > + uint8_t *data = g_new(uint8_t, ndata);
> > +
> > + sector = cpu_to_le64((uint32_t)sector);
>
> Why casting to 32 bit?
Bugtastic.
> > + memcpy(data, (uint8_t *)§or, ndata);
> > + if (sizeof(sector) < ndata) {
> > + memset(data + sizeof(sector), 0, ndata - sizeof(sector));
> > + }
> > +
> > + if (qcrypto_cipher_encrypt(essiv->cipher,
> > + data,
> > + data,
> > + ndata,
> > + errp) < 0) {
> > + g_free(data);
> > + return -1;
> > + }
> > +
> > + if (ndata > niv) {
> > + ndata = niv;
> > + }
> > + memcpy(iv, data, ndata);
> > + if (ndata < niv) {
> > + memset(iv + ndata, 0, niv - ndata);
> > + }
> > + g_free(data);
> > + return 0;
> > +}
> > +
> > +static void qcrypto_ivgen_essiv_cleanup(QCryptoIVGen *ivgen)
> > +{
> > + QCryptoIVGenESSIV *essiv = ivgen->private;
> > +
> > + qcrypto_cipher_free(essiv->cipher);
> > + g_free(essiv);
> > +}
> > +
> > +
> > +struct QCryptoIVGenDriver qcrypto_ivgen_essiv = {
> > + qcrypto_ivgen_essiv_init,
>
> It'd be more readable to explicitly write
>
> .init = qcrypto_ivgen_essiv_init,
> .calculate = ...,
> .cleanup = ...
>
> but it is fine since there are only three operations now.
Yeah, I normally do it that way anyway, so will change it.
Regards,
Daniel
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