authencesn compatibility problemn between software crypto and talitos driver

[Chaoxing Lin <Chaoxing.Lin@xxxxxxxxxxxxxx>]

1. Can any one point me which RFC describe how exactly authencesn should work?

2. I test Ipsec with "esp=aes256-sha512-esn!" options and found compatibility issue between kernel software crypto and talitos driver.
Talitos <---->talitos				Good
Soft crypto<---->soft crypto			Good
Soft crypto<---->talitos			link established but no traffic can pass through.

3. Looking at source code of latest stable kernel 3.8.2, I found that these two implementations don't agree on what's to be hashed in ESN case.
Talitos driver is more intuitive in that  "assoc (SPI, SN-hi, SN-low) + IV + payload" are hashed.
Kernel software crypto is counter-intuitive in that "hsg(SPI, SN-low) + sg(IV + payload) + tsg(SN-hi" are hashed.
I copy codelet from kernel 3.8.2 in the end.

Please let me know whether I read the code right. And which way is the right way.

Thanks

Chaoxing
 
Code from latest stable kernel 3.8.2

path: root/drivers/crypto/talitos.c

969: /* hmac data */
970:	desc->ptr[1].len = cpu_to_be16(areq->assoclen + ivsize);
	if (edesc->assoc_nents) {
		int tbl_off = edesc->src_nents + edesc->dst_nents + 2;
		struct talitos_ptr *tbl_ptr = &edesc->link_tbl[tbl_off];

		to_talitos_ptr(&desc->ptr[1], edesc->dma_link_tbl + tbl_off *
			       sizeof(struct talitos_ptr));
		desc->ptr[1].j_extent = DESC_PTR_LNKTBL_JUMP;

		/* assoc_nents - 1 entries for assoc, 1 for IV */
		sg_count = sg_to_link_tbl(areq->assoc, edesc->assoc_nents - 1,
					  areq->assoclen, tbl_ptr);

		/* add IV to link table */
		tbl_ptr += sg_count - 1;
		tbl_ptr->j_extent = 0;
		tbl_ptr++;
		to_talitos_ptr(tbl_ptr, edesc->iv_dma);
		tbl_ptr->len = cpu_to_be16(ivsize);
		tbl_ptr->j_extent = DESC_PTR_LNKTBL_RETURN;

		dma_sync_single_for_device(dev, edesc->dma_link_tbl,
					   edesc->dma_len, DMA_BIDIRECTIONAL);
	} else {
		to_talitos_ptr(&desc->ptr[1], sg_dma_address(areq->assoc));
		desc->ptr[1].j_extent = 0;
996:	}



path: root/crypto/authencesn.c

372:	err = crypto_ahash_init(ahreq);
373:	if (err)
		return ERR_PTR(err);

	ahash_request_set_crypt(ahreq, areq_ctx->hsg, hash, areq_ctx->headlen);
	ahash_request_set_callback(ahreq, aead_request_flags(req) & flags,
				   areq_ctx->update_complete, req);

	err = crypto_ahash_update(ahreq);
	if (err)
		return ERR_PTR(err);

	ahash_request_set_crypt(ahreq, areq_ctx->sg, hash, areq_ctx->cryptlen);
	ahash_request_set_callback(ahreq, aead_request_flags(req) & flags,
				   areq_ctx->update_complete2, req);

	err = crypto_ahash_update(ahreq);
	if (err)
		return ERR_PTR(err);

	ahash_request_set_crypt(ahreq, areq_ctx->tsg, hash,
				areq_ctx->trailen);
	ahash_request_set_callback(ahreq, aead_request_flags(req) & flags,
				   areq_ctx->complete, req);

397:	err = crypto_ahash_finup(ahreq);
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