Hi Herbert,
On Wednesday 08 July 2015 09:48 AM, Herbert Xu wrote:
> On Tue, Jul 07, 2015 at 09:01:48PM +0530, Lokesh Vutla wrote:
>>
>> +static int omap_aes_gcm_copy_buffers(struct omap_aes_dev *dd,
>> + struct aead_request *req)
[..snip..]
>> +static int do_encrypt_iv(struct aead_request *req, u32 *tag)
>> +{
>> + struct scatterlist iv_sg;
>> + struct ablkcipher_request *ablk_req;
>> + struct crypto_ablkcipher *tfm;
>> + struct tcrypt_result result;
>> + struct omap_aes_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
>> + int ret = 0;
>> +
>> + tfm = crypto_alloc_ablkcipher("ctr(aes)", 0, 0);
>
> Ugh, you cannot allocate crypto transforms in the data path. You
> should allocate it in init instead. Also using ctr(aes) is overkill.
> Just use aes and do the xor by hand.
>
>> +static int omap_aes_gcm_crypt(struct aead_request *req, unsigned long mode)
>> +{
>> + struct omap_aes_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
>> + struct omap_aes_reqctx *rctx = aead_request_ctx(req);
>> + struct crypto_aead *aead = crypto_aead_reqtfm(req);
>> + unsigned int authlen = crypto_aead_authsize(aead);
>> + struct omap_aes_dev *dd;
>> + __be32 counter = cpu_to_be32(1);
>> + int err;
>> +
>> + memset(ctx->auth_tag, 0, sizeof(ctx->auth_tag));
>
> The ctx is shared memory and you must not write to it as multiple
> requests can be called on the same tfm. Use rctx instead.
May be a dumb question.
If you don't mind can you elaborate more on the usage of rctx and ctx
in the driver?
Thanks and regards,
Lokesh
>
>> + memcpy(req->iv + 12, &counter, 4);
>
> The IV is only 12 bytes long so you're corrupting memory here.
> You should use rctx here too.
>
>> + if (req->assoclen + req->cryptlen == 0) {
>> + scatterwalk_map_and_copy(ctx->auth_tag, req->dst, 0, authlen,
>> + 1);
>> + return 0;
>> + }
>
> How can this be right? Did you enable the selftest?
>
> Cheers,
>
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