On Thu, 5 Jun 2008 15:22:24 +1000
Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> wrote:
> On Fri, May 30, 2008 at 06:58:30PM -0500, Kim Phillips wrote:
> >
> > + /* get random IV */
> > + get_random_bytes(req->giv, crypto_aead_ivsize(authenc));
>
> Sorry but this is unworkable given our current RNG infrastructure.
> Draining 16 bytes for every packet is going to make /dev/random
> unuseable (if it wasn't already :).
it is :). I'm working on it :).
> Perhaps just use eseqiv (it should be pretty cheap sinec it just
> tacks on an extra block to the encryption) for now until we have
> a PRNG?
the h/w has a IV out feature we should probably be using. How about
something like this (UNTESTED):
diff --git a/drivers/crypto/talitos.c b/drivers/crypto/talitos.c
index cf2e6f3..5ebb0f1 100644
--- a/drivers/crypto/talitos.c
+++ b/drivers/crypto/talitos.c
@@ -566,6 +566,7 @@ struct talitos_ctx {
struct device *dev;
__be32 desc_hdr_template;
u8 key[TALITOS_MAX_KEY_SIZE];
+ u8 iv[TALITOS_AES_IV_LENGTH];
unsigned int keylen;
unsigned int enckeylen;
unsigned int authkeylen;
@@ -873,8 +874,9 @@ static int ipsec_esp(struct ipsec_esp_edesc *edesc, struct aead_request *areq,
edesc->dma_len, DMA_BIDIRECTIONAL);
}
- /* optional iv out - entry points use random IVs instead */
- desc->ptr[6].len = 0;
+ /* iv out */
+ map_single_talitos_ptr(dev, &desc->ptr[6], ivsize, ctx->iv, 0,
+ DMA_FROM_DEVICE);
return talitos_submit(dev, desc, callback, areq);
}
@@ -1020,8 +1022,7 @@ static int aes_cbc_sha1_hmac_authenc_givencrypt(
/* set encrypt */
edesc->desc.hdr = ctx->desc_hdr_template | DESC_HDR_MODE0_AESU_ENC;
- /* get random IV */
- get_random_bytes(req->giv, crypto_aead_ivsize(authenc));
+ memcpy(req->giv, ctx->iv, crypto_aead_ivsize(authenc));
return ipsec_esp(edesc, areq, req->giv, req->seq,
ipsec_esp_encrypt_done);
@@ -1081,6 +1082,9 @@ static int talitos_cra_init(struct crypto_tfm *tfm)
/* copy descriptor header template value */
ctx->desc_hdr_template = talitos_alg->desc_hdr_template;
+ /* random first IV */
+ get_random_bytes(ctx->iv, TALITOS_AES_IV_LENGTH);
+
return 0;
}
Kim
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