Пример #1
0
void
g_eli_auth_read(struct g_eli_softc *sc, struct bio *bp)
{
	struct g_consumer *cp;
	struct bio *cbp, *cbp2;
	size_t size;
	off_t nsec;

	bp->bio_pflags = 0;

	cp = LIST_FIRST(&sc->sc_geom->consumer);
	cbp = bp->bio_driver1;
	bp->bio_driver1 = NULL;
	cbp->bio_to = cp->provider;
	cbp->bio_done = g_eli_read_done;

	/* Number of sectors from decrypted provider, eg. 1. */
	nsec = bp->bio_length / bp->bio_to->sectorsize;
	/* Number of sectors from encrypted provider, eg. 9. */
	nsec = (nsec * sc->sc_bytes_per_sector) / cp->provider->sectorsize;

	cbp->bio_length = cp->provider->sectorsize * nsec;
	size = cbp->bio_length;
	size += sc->sc_alen * nsec;
	size += sizeof(struct cryptop) * nsec;
	size += sizeof(struct cryptodesc) * nsec * 2;
	size += G_ELI_AUTH_SECKEYLEN * nsec;
	size += sizeof(struct uio) * nsec;
	size += sizeof(struct iovec) * nsec;
	cbp->bio_offset = (bp->bio_offset / bp->bio_to->sectorsize) * sc->sc_bytes_per_sector;
	bp->bio_driver2 = malloc(size, M_ELI, M_WAITOK);
	cbp->bio_data = bp->bio_driver2;

	/*
	 * We read more than what is requested, so we have to be ready to read
	 * more than MAXPHYS.
	 */
	cbp2 = NULL;
	if (cbp->bio_length > MAXPHYS) {
		cbp2 = g_duplicate_bio(bp);
		cbp2->bio_length = cbp->bio_length - MAXPHYS;
		cbp2->bio_data = cbp->bio_data + MAXPHYS;
		cbp2->bio_offset = cbp->bio_offset + MAXPHYS;
		cbp2->bio_to = cp->provider;
		cbp2->bio_done = g_eli_read_done;
		cbp->bio_length = MAXPHYS;
	}
	/*
	 * Read encrypted data from provider.
	 */
	G_ELI_LOGREQ(2, cbp, "Sending request.");
	g_io_request(cbp, cp);
	if (cbp2 != NULL) {
		G_ELI_LOGREQ(2, cbp2, "Sending request.");
		g_io_request(cbp2, cp);
	}
}
Пример #2
0
/*
 * The function is called after data encryption.
 *
 * g_eli_start -> g_eli_crypto_run -> G_ELI_CRYPTO_WRITE_DONE -> g_io_request -> g_eli_write_done -> g_io_deliver
 */
static int
g_eli_crypto_write_done(struct cryptop *crp)
{
	struct g_eli_softc *sc;
	struct g_geom *gp;
	struct g_consumer *cp;
	struct bio *bp, *cbp;

	if (crp->crp_etype == EAGAIN) {
		if (g_eli_crypto_rerun(crp) == 0)
			return (0);
	}
	bp = (struct bio *)crp->crp_opaque;
	bp->bio_inbed++;
	if (crp->crp_etype == 0) {
		G_ELI_DEBUG(3, "Crypto WRITE request done (%d/%d).",
		    bp->bio_inbed, bp->bio_children);
	} else {
		G_ELI_DEBUG(1, "Crypto WRITE request failed (%d/%d) error=%d.",
		    bp->bio_inbed, bp->bio_children, crp->crp_etype);
		if (bp->bio_error == 0)
			bp->bio_error = crp->crp_etype;
	}
	gp = bp->bio_to->geom;
	sc = gp->softc;
	g_eli_key_drop(sc, crp->crp_desc->crd_key);
	/*
	 * All sectors are already encrypted?
	 */
	if (bp->bio_inbed < bp->bio_children)
		return (0);
	bp->bio_inbed = 0;
	bp->bio_children = 1;
	cbp = bp->bio_driver1;
	bp->bio_driver1 = NULL;
	if (bp->bio_error != 0) {
		G_ELI_LOGREQ(0, bp, "Crypto WRITE request failed (error=%d).",
		    bp->bio_error);
		free(bp->bio_driver2, M_ELI);
		bp->bio_driver2 = NULL;
		g_destroy_bio(cbp);
		g_io_deliver(bp, bp->bio_error);
		atomic_subtract_int(&sc->sc_inflight, 1);
		return (0);
	}
	cbp->bio_data = bp->bio_driver2;
	cbp->bio_done = g_eli_write_done;
	cp = LIST_FIRST(&gp->consumer);
	cbp->bio_to = cp->provider;
	G_ELI_LOGREQ(2, cbp, "Sending request.");
	/*
	 * Send encrypted data to the provider.
	 */
	g_io_request(cbp, cp);
	return (0);
}
Пример #3
0
/*
 * The function is called after we read and decrypt data.
 *
 * g_eli_start -> g_eli_crypto_read -> g_io_request -> g_eli_read_done -> g_eli_crypto_run -> G_ELI_CRYPTO_READ_DONE -> g_io_deliver
 */
static int
g_eli_crypto_read_done(struct cryptop *crp)
{
	struct g_eli_softc *sc;
	struct bio *bp;

	if (crp->crp_etype == EAGAIN) {
		if (g_eli_crypto_rerun(crp) == 0)
			return (0);
	}
	bp = (struct bio *)crp->crp_opaque;
	bp->bio_inbed++;
	if (crp->crp_etype == 0) {
		G_ELI_DEBUG(3, "Crypto READ request done (%d/%d).",
		    bp->bio_inbed, bp->bio_children);
		bp->bio_completed += crp->crp_olen;
	} else {
		G_ELI_DEBUG(1, "Crypto READ request failed (%d/%d) error=%d.",
		    bp->bio_inbed, bp->bio_children, crp->crp_etype);
		if (bp->bio_error == 0)
			bp->bio_error = crp->crp_etype;
	}
	sc = bp->bio_to->geom->softc;
	g_eli_key_drop(sc, crp->crp_desc->crd_key);
	/*
	 * Do we have all sectors already?
	 */
	if (bp->bio_inbed < bp->bio_children)
		return (0);
	free(bp->bio_driver2, M_ELI);
	bp->bio_driver2 = NULL;
	if (bp->bio_error != 0) {
		G_ELI_LOGREQ(0, bp, "Crypto READ request failed (error=%d).",
		    bp->bio_error);
		bp->bio_completed = 0;
	}
	/*
	 * Read is finished, send it up.
	 */
	g_io_deliver(bp, bp->bio_error);
	atomic_subtract_int(&sc->sc_inflight, 1);
	return (0);
}
Пример #4
0
/*
 * The function is called to read encrypted data.
 *
 * g_eli_start -> G_ELI_CRYPTO_READ -> g_io_request -> g_eli_read_done -> g_eli_crypto_run -> g_eli_crypto_read_done -> g_io_deliver
 */
void
g_eli_crypto_read(struct g_eli_softc *sc, struct bio *bp, boolean_t fromworker)
{
	struct g_consumer *cp;
	struct bio *cbp;

	if (!fromworker) {
		/*
		 * We are not called from the worker thread, so check if
		 * device is suspended.
		 */
		mtx_lock(&sc->sc_queue_mtx);
		if (sc->sc_flags & G_ELI_FLAG_SUSPEND) {
			/*
			 * If device is suspended, we place the request onto
			 * the queue, so it can be handled after resume.
			 */
			G_ELI_DEBUG(0, "device suspended, move onto queue");
			bioq_insert_tail(&sc->sc_queue, bp);
			mtx_unlock(&sc->sc_queue_mtx);
			wakeup(sc);
			return;
		}
		atomic_add_int(&sc->sc_inflight, 1);
		mtx_unlock(&sc->sc_queue_mtx);
	}
	bp->bio_pflags = 0;
	bp->bio_driver2 = NULL;
	cbp = bp->bio_driver1;
	cbp->bio_done = g_eli_read_done;
	cp = LIST_FIRST(&sc->sc_geom->consumer);
	cbp->bio_to = cp->provider;
	G_ELI_LOGREQ(2, cbp, "Sending request.");
	/*
	 * Read encrypted data from provider.
	 */
	g_io_request(cbp, cp);
}
Пример #5
0
/*
 * This is the main function responsible for cryptography (ie. communication
 * with crypto(9) subsystem).
 *
 * BIO_READ:
 *	g_eli_start -> g_eli_crypto_read -> g_io_request -> g_eli_read_done -> G_ELI_CRYPTO_RUN -> g_eli_crypto_read_done -> g_io_deliver
 * BIO_WRITE:
 *	g_eli_start -> G_ELI_CRYPTO_RUN -> g_eli_crypto_write_done -> g_io_request -> g_eli_write_done -> g_io_deliver
 */
void
g_eli_crypto_run(struct g_eli_worker *wr, struct bio *bp)
{
	struct g_eli_softc *sc;
	struct cryptop *crp;
	struct cryptodesc *crd;
	u_int i, nsec, secsize;
	int err, error;
	off_t dstoff;
	size_t size;
	u_char *p, *data;

	G_ELI_LOGREQ(3, bp, "%s", __func__);

	bp->bio_pflags = wr->w_number;
	sc = wr->w_softc;
	secsize = LIST_FIRST(&sc->sc_geom->provider)->sectorsize;
	nsec = bp->bio_length / secsize;

	/*
	 * Calculate how much memory do we need.
	 * We need separate crypto operation for every single sector.
	 * It is much faster to calculate total amount of needed memory here and
	 * do the allocation once instead of allocating memory in pieces (many,
	 * many pieces).
	 */
	size = sizeof(*crp) * nsec;
	size += sizeof(*crd) * nsec;
	/*
	 * If we write the data we cannot destroy current bio_data content,
	 * so we need to allocate more memory for encrypted data.
	 */
	if (bp->bio_cmd == BIO_WRITE)
		size += bp->bio_length;
	p = malloc(size, M_ELI, M_WAITOK);

	bp->bio_inbed = 0;
	bp->bio_children = nsec;
	bp->bio_driver2 = p;

	if (bp->bio_cmd == BIO_READ)
		data = bp->bio_data;
	else {
		data = p;
		p += bp->bio_length;
		bcopy(bp->bio_data, data, bp->bio_length);
	}

	error = 0;
	for (i = 0, dstoff = bp->bio_offset; i < nsec; i++, dstoff += secsize) {
		crp = (struct cryptop *)p;	p += sizeof(*crp);
		crd = (struct cryptodesc *)p;	p += sizeof(*crd);

		crp->crp_sid = wr->w_sid;
		crp->crp_ilen = secsize;
		crp->crp_olen = secsize;
		crp->crp_opaque = (void *)bp;
		crp->crp_buf = (void *)data;
		data += secsize;
		if (bp->bio_cmd == BIO_WRITE)
			crp->crp_callback = g_eli_crypto_write_done;
		else /* if (bp->bio_cmd == BIO_READ) */
			crp->crp_callback = g_eli_crypto_read_done;
		crp->crp_flags = CRYPTO_F_CBIFSYNC;
		if (g_eli_batch)
			crp->crp_flags |= CRYPTO_F_BATCH;
		crp->crp_desc = crd;

		crd->crd_skip = 0;
		crd->crd_len = secsize;
		crd->crd_flags = CRD_F_IV_EXPLICIT | CRD_F_IV_PRESENT;
		if ((sc->sc_flags & G_ELI_FLAG_SINGLE_KEY) == 0)
			crd->crd_flags |= CRD_F_KEY_EXPLICIT;
		if (bp->bio_cmd == BIO_WRITE)
			crd->crd_flags |= CRD_F_ENCRYPT;
		crd->crd_alg = sc->sc_ealgo;
		crd->crd_key = g_eli_key_hold(sc, dstoff, secsize);
		crd->crd_klen = sc->sc_ekeylen;
		if (sc->sc_ealgo == CRYPTO_AES_XTS)
			crd->crd_klen <<= 1;
		g_eli_crypto_ivgen(sc, dstoff, crd->crd_iv,
		    sizeof(crd->crd_iv));
		crd->crd_next = NULL;

		crp->crp_etype = 0;
		err = crypto_dispatch(crp);
		if (error == 0)
			error = err;
	}
	if (bp->bio_error == 0)
		bp->bio_error = error;
}
Пример #6
0
/*
 * This is the main function responsible for cryptography (ie. communication
 * with crypto(9) subsystem).
 *
 * BIO_READ:
 *	g_eli_start -> g_eli_auth_read -> g_io_request -> g_eli_read_done -> G_ELI_AUTH_RUN -> g_eli_auth_read_done -> g_io_deliver
 * BIO_WRITE:
 *	g_eli_start -> G_ELI_AUTH_RUN -> g_eli_auth_write_done -> g_io_request -> g_eli_write_done -> g_io_deliver
 */
void
g_eli_auth_run(struct g_eli_worker *wr, struct bio *bp)
{
	struct g_eli_softc *sc;
	struct cryptop *crp;
	struct cryptodesc *crde, *crda;
	struct uio *uio;
	struct iovec *iov;
	u_int i, lsec, nsec, data_secsize, decr_secsize, encr_secsize;
	off_t dstoff;
	int err, error;
	u_char *p, *data, *auth, *authkey, *plaindata;

	G_ELI_LOGREQ(3, bp, "%s", __func__);

	bp->bio_pflags = wr->w_number;
	sc = wr->w_softc;
	/* Sectorsize of decrypted provider eg. 4096. */
	decr_secsize = bp->bio_to->sectorsize;
	/* The real sectorsize of encrypted provider, eg. 512. */
	encr_secsize = LIST_FIRST(&sc->sc_geom->consumer)->provider->sectorsize;
	/* Number of data bytes in one encrypted sector, eg. 480. */
	data_secsize = sc->sc_data_per_sector;
	/* Number of sectors from decrypted provider, eg. 2. */
	nsec = bp->bio_length / decr_secsize;
	/* Number of sectors from encrypted provider, eg. 18. */
	nsec = (nsec * sc->sc_bytes_per_sector) / encr_secsize;
	/* Last sector number in every big sector, eg. 9. */
	lsec = sc->sc_bytes_per_sector / encr_secsize;
	/* Destination offset, used for IV generation. */
	dstoff = (bp->bio_offset / bp->bio_to->sectorsize) * sc->sc_bytes_per_sector;

	auth = NULL;	/* Silence compiler warning. */
	plaindata = bp->bio_data;
	if (bp->bio_cmd == BIO_READ) {
		data = bp->bio_driver2;
		auth = data + encr_secsize * nsec;
		p = auth + sc->sc_alen * nsec;
	} else {
		size_t size;

		size = encr_secsize * nsec;
		size += sizeof(*crp) * nsec;
		size += sizeof(*crde) * nsec;
		size += sizeof(*crda) * nsec;
		size += G_ELI_AUTH_SECKEYLEN * nsec;
		size += sizeof(*uio) * nsec;
		size += sizeof(*iov) * nsec;
		data = malloc(size, M_ELI, M_WAITOK);
		bp->bio_driver2 = data;
		p = data + encr_secsize * nsec;
	}
	bp->bio_inbed = 0;
	bp->bio_children = nsec;

	error = 0;
	for (i = 1; i <= nsec; i++, dstoff += encr_secsize) {
		crp = (struct cryptop *)p;	p += sizeof(*crp);
		crde = (struct cryptodesc *)p;	p += sizeof(*crde);
		crda = (struct cryptodesc *)p;	p += sizeof(*crda);
		authkey = (u_char *)p;		p += G_ELI_AUTH_SECKEYLEN;
		uio = (struct uio *)p;		p += sizeof(*uio);
		iov = (struct iovec *)p;	p += sizeof(*iov);

		data_secsize = sc->sc_data_per_sector;
		if ((i % lsec) == 0)
			data_secsize = decr_secsize % data_secsize;

		if (bp->bio_cmd == BIO_READ) {
			/* Remember read HMAC. */
			bcopy(data, auth, sc->sc_alen);
			auth += sc->sc_alen;
			/* TODO: bzero(9) can be commented out later. */
			bzero(data, sc->sc_alen);
		} else {
			bcopy(plaindata, data + sc->sc_alen, data_secsize);
			plaindata += data_secsize;
		}

		iov->iov_len = sc->sc_alen + data_secsize;
		iov->iov_base = data;
		data += encr_secsize;

		uio->uio_iov = iov;
		uio->uio_iovcnt = 1;
		uio->uio_segflg = UIO_SYSSPACE;
		uio->uio_resid = iov->iov_len;

		crp->crp_sid = wr->w_sid;
		crp->crp_ilen = uio->uio_resid;
		crp->crp_olen = data_secsize;
		crp->crp_opaque = (void *)bp;
		crp->crp_buf = (void *)uio;
		crp->crp_flags = CRYPTO_F_IOV | CRYPTO_F_CBIFSYNC | CRYPTO_F_REL;
		if (g_eli_batch)
			crp->crp_flags |= CRYPTO_F_BATCH;
		if (bp->bio_cmd == BIO_WRITE) {
			crp->crp_callback = g_eli_auth_write_done;
			crp->crp_desc = crde;
			crde->crd_next = crda;
			crda->crd_next = NULL;
		} else {
			crp->crp_callback = g_eli_auth_read_done;
			crp->crp_desc = crda;
			crda->crd_next = crde;
			crde->crd_next = NULL;
		}

		crde->crd_skip = sc->sc_alen;
		crde->crd_len = data_secsize;
		crde->crd_flags = CRD_F_IV_EXPLICIT | CRD_F_IV_PRESENT;
		if ((sc->sc_flags & G_ELI_FLAG_FIRST_KEY) == 0)
			crde->crd_flags |= CRD_F_KEY_EXPLICIT;
		if (bp->bio_cmd == BIO_WRITE)
			crde->crd_flags |= CRD_F_ENCRYPT;
		crde->crd_alg = sc->sc_ealgo;
		crde->crd_key = g_eli_key_hold(sc, dstoff, encr_secsize);
		crde->crd_klen = sc->sc_ekeylen;
		if (sc->sc_ealgo == CRYPTO_AES_XTS)
			crde->crd_klen <<= 1;
		g_eli_crypto_ivgen(sc, dstoff, crde->crd_iv,
		    sizeof(crde->crd_iv));

		crda->crd_skip = sc->sc_alen;
		crda->crd_len = data_secsize;
		crda->crd_inject = 0;
		crda->crd_flags = CRD_F_KEY_EXPLICIT;
		crda->crd_alg = sc->sc_aalgo;
		g_eli_auth_keygen(sc, dstoff, authkey);
		crda->crd_key = authkey;
		crda->crd_klen = G_ELI_AUTH_SECKEYLEN * 8;

		crp->crp_etype = 0;
		err = crypto_dispatch(crp);
		if (err != 0 && error == 0)
			error = err;
	}
	if (bp->bio_error == 0)
		bp->bio_error = error;
}
Пример #7
0
/*
 * The function is called after data encryption.
 *
 * g_eli_start -> g_eli_auth_run -> G_ELI_AUTH_WRITE_DONE -> g_io_request -> g_eli_write_done -> g_io_deliver
 */
static int
g_eli_auth_write_done(struct cryptop *crp)
{
	struct g_eli_softc *sc;
	struct g_consumer *cp;
	struct bio *bp, *cbp, *cbp2;
	u_int nsec;

	if (crp->crp_etype == EAGAIN) {
		if (g_eli_crypto_rerun(crp) == 0)
			return (0);
	}
	bp = (struct bio *)crp->crp_opaque;
	bp->bio_inbed++;
	if (crp->crp_etype == 0) {
		G_ELI_DEBUG(3, "Crypto WRITE request done (%d/%d).",
		    bp->bio_inbed, bp->bio_children);
	} else {
		G_ELI_DEBUG(1, "Crypto WRITE request failed (%d/%d) error=%d.",
		    bp->bio_inbed, bp->bio_children, crp->crp_etype);
		if (bp->bio_error == 0)
			bp->bio_error = crp->crp_etype;
	}
	sc = bp->bio_to->geom->softc;
	g_eli_key_drop(sc, crp->crp_desc->crd_key);
	/*
	 * All sectors are already encrypted?
	 */
	if (bp->bio_inbed < bp->bio_children)
		return (0);
	if (bp->bio_error != 0) {
		G_ELI_LOGREQ(0, bp, "Crypto WRITE request failed (error=%d).",
		    bp->bio_error);
		free(bp->bio_driver2, M_ELI);
		bp->bio_driver2 = NULL;
		cbp = bp->bio_driver1;
		bp->bio_driver1 = NULL;
		g_destroy_bio(cbp);
		g_io_deliver(bp, bp->bio_error);
		atomic_subtract_int(&sc->sc_inflight, 1);
		return (0);
	}
	cp = LIST_FIRST(&sc->sc_geom->consumer);
	cbp = bp->bio_driver1;
	bp->bio_driver1 = NULL;
	cbp->bio_to = cp->provider;
	cbp->bio_done = g_eli_write_done;

	/* Number of sectors from decrypted provider, eg. 1. */
	nsec = bp->bio_length / bp->bio_to->sectorsize;
	/* Number of sectors from encrypted provider, eg. 9. */
	nsec = (nsec * sc->sc_bytes_per_sector) / cp->provider->sectorsize;

	cbp->bio_length = cp->provider->sectorsize * nsec;
	cbp->bio_offset = (bp->bio_offset / bp->bio_to->sectorsize) * sc->sc_bytes_per_sector;
	cbp->bio_data = bp->bio_driver2;

	/*
	 * We write more than what is requested, so we have to be ready to write
	 * more than MAXPHYS.
	 */
	cbp2 = NULL;
	if (cbp->bio_length > MAXPHYS) {
		cbp2 = g_duplicate_bio(bp);
		cbp2->bio_length = cbp->bio_length - MAXPHYS;
		cbp2->bio_data = cbp->bio_data + MAXPHYS;
		cbp2->bio_offset = cbp->bio_offset + MAXPHYS;
		cbp2->bio_to = cp->provider;
		cbp2->bio_done = g_eli_write_done;
		cbp->bio_length = MAXPHYS;
	}
	/*
	 * Send encrypted data to the provider.
	 */
	G_ELI_LOGREQ(2, cbp, "Sending request.");
	bp->bio_inbed = 0;
	bp->bio_children = (cbp2 != NULL ? 2 : 1);
	g_io_request(cbp, cp);
	if (cbp2 != NULL) {
		G_ELI_LOGREQ(2, cbp2, "Sending request.");
		g_io_request(cbp2, cp);
	}
	return (0);
}
Пример #8
0
/*
 * The function is called after we read and decrypt data.
 *
 * g_eli_start -> g_eli_auth_read -> g_io_request -> g_eli_read_done -> g_eli_auth_run -> G_ELI_AUTH_READ_DONE -> g_io_deliver
 */
static int
g_eli_auth_read_done(struct cryptop *crp)
{
	struct g_eli_softc *sc;
	struct bio *bp;

	if (crp->crp_etype == EAGAIN) {
		if (g_eli_crypto_rerun(crp) == 0)
			return (0);
	}
	bp = (struct bio *)crp->crp_opaque;
	bp->bio_inbed++;
	if (crp->crp_etype == 0) {
		bp->bio_completed += crp->crp_olen;
		G_ELI_DEBUG(3, "Crypto READ request done (%d/%d) (add=%jd completed=%jd).",
		    bp->bio_inbed, bp->bio_children, (intmax_t)crp->crp_olen, (intmax_t)bp->bio_completed);
	} else {
		G_ELI_DEBUG(1, "Crypto READ request failed (%d/%d) error=%d.",
		    bp->bio_inbed, bp->bio_children, crp->crp_etype);
		if (bp->bio_error == 0)
			bp->bio_error = crp->crp_etype;
	}
	sc = bp->bio_to->geom->softc;
	g_eli_key_drop(sc, crp->crp_desc->crd_next->crd_key);
	/*
	 * Do we have all sectors already?
	 */
	if (bp->bio_inbed < bp->bio_children)
		return (0);
	if (bp->bio_error == 0) {
		u_int i, lsec, nsec, data_secsize, decr_secsize, encr_secsize;
		u_char *srcdata, *dstdata, *auth;
		off_t coroff, corsize;

		/*
		 * Verify data integrity based on calculated and read HMACs.
		 */
		/* Sectorsize of decrypted provider eg. 4096. */
		decr_secsize = bp->bio_to->sectorsize;
		/* The real sectorsize of encrypted provider, eg. 512. */
		encr_secsize = LIST_FIRST(&sc->sc_geom->consumer)->provider->sectorsize;
		/* Number of data bytes in one encrypted sector, eg. 480. */
		data_secsize = sc->sc_data_per_sector;
		/* Number of sectors from decrypted provider, eg. 2. */
		nsec = bp->bio_length / decr_secsize;
		/* Number of sectors from encrypted provider, eg. 18. */
		nsec = (nsec * sc->sc_bytes_per_sector) / encr_secsize;
		/* Last sector number in every big sector, eg. 9. */
		lsec = sc->sc_bytes_per_sector / encr_secsize;

		srcdata = bp->bio_driver2;
		dstdata = bp->bio_data;
		auth = srcdata + encr_secsize * nsec;
		coroff = -1;
		corsize = 0;

		for (i = 1; i <= nsec; i++) {
			data_secsize = sc->sc_data_per_sector;
			if ((i % lsec) == 0)
				data_secsize = decr_secsize % data_secsize;
			if (bcmp(srcdata, auth, sc->sc_alen) != 0) {
				/*
				 * Curruption detected, remember the offset if
				 * this is the first corrupted sector and
				 * increase size.
				 */
				if (bp->bio_error == 0)
					bp->bio_error = -1;
				if (coroff == -1) {
					coroff = bp->bio_offset +
					    (dstdata - (u_char *)bp->bio_data);
				}
				corsize += data_secsize;
			} else {
				/*
				 * No curruption, good.
				 * Report previous corruption if there was one.
				 */
				if (coroff != -1) {
					G_ELI_DEBUG(0, "%s: Failed to authenticate %jd "
					    "bytes of data at offset %jd.",
					    sc->sc_name, (intmax_t)corsize,
					    (intmax_t)coroff);
					coroff = -1;
					corsize = 0;
				}
				bcopy(srcdata + sc->sc_alen, dstdata,
				    data_secsize);
			}
			srcdata += encr_secsize;
			dstdata += data_secsize;
			auth += sc->sc_alen;
		}
		/* Report previous corruption if there was one. */
		if (coroff != -1) {
			G_ELI_DEBUG(0, "%s: Failed to authenticate %jd "
			    "bytes of data at offset %jd.",
			    sc->sc_name, (intmax_t)corsize, (intmax_t)coroff);
		}
	}
	free(bp->bio_driver2, M_ELI);
	bp->bio_driver2 = NULL;
	if (bp->bio_error != 0) {
		if (bp->bio_error == -1)
			bp->bio_error = EINVAL;
		else {
			G_ELI_LOGREQ(0, bp,
			    "Crypto READ request failed (error=%d).",
			    bp->bio_error);
		}
		bp->bio_completed = 0;
	}
	/*
	 * Read is finished, send it up.
	 */
	g_io_deliver(bp, bp->bio_error);
	atomic_subtract_int(&sc->sc_inflight, 1);
	return (0);
}