Re: [PATCH 06/10] crypto: omap-aes: gcm: Handle inputs properly

[Lokesh Vutla <lokeshvutla@ti.com>]

On Thursday 02 July 2015 01:34 PM, Felipe Balbi wrote:
> On Thu, Jul 02, 2015 at 10:48:36AM +0530, Lokesh Vutla wrote:
>> Its not necessary that assoc data and plain text is passed always.
>> Add these checks before processing the input.
>>
>> Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
> 
> why can't this be combined with patch which added GCM in the first
> place ?
Yes, my initial patch is all combined. But it was very big.
I tried my best in breaking down into different patches inorder to
help reviewer.
So, I kept the functionality part in one patch, and handled corner case
like these in separate patches.

Thanks and regards,
Lokesh

> 
>> ---
>>  drivers/crypto/omap-aes-gcm.c |   26 ++++++++++++++++++++------
>>  1 file changed, 20 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/crypto/omap-aes-gcm.c b/drivers/crypto/omap-aes-gcm.c
>> index 1be9d91..72815af 100644
>> --- a/drivers/crypto/omap-aes-gcm.c
>> +++ b/drivers/crypto/omap-aes-gcm.c
>> @@ -87,7 +87,7 @@ static int omap_aes_gcm_copy_buffers(struct omap_aes_dev *dd,
>>  				     struct aead_request *req)
>>  {
>>  	void *buf_in;
>> -	int alen, clen;
>> +	int alen, clen, nsg;
>>  	struct crypto_aead *aead = crypto_aead_reqtfm(req);
>>  	unsigned int authlen = crypto_aead_authsize(aead);
>>  	u32 dec = !(dd->flags & FLAGS_ENCRYPT);
>> @@ -97,12 +97,18 @@ static int omap_aes_gcm_copy_buffers(struct omap_aes_dev *dd,
>>  
>>  	dd->sgs_copied = 0;
>>  
>> -	sg_init_table(dd->in_sgl, 2);
>> -	buf_in = sg_virt(req->assoc);
>> -	sg_set_buf(dd->in_sgl, buf_in, alen);
>> +	nsg = 1 + !!(req->assoclen && req->cryptlen);
>>  
>> -	buf_in = sg_virt(req->src);
>> -	sg_set_buf(&dd->in_sgl[1], buf_in, clen);
>> +	sg_init_table(dd->in_sgl, nsg);
>> +	if (req->assoclen) {
>> +		buf_in = sg_virt(req->assoc);
>> +		sg_set_buf(dd->in_sgl, buf_in, alen);
>> +	}
>> +
>> +	if (req->cryptlen) {
>> +		buf_in = sg_virt(req->src);
>> +		sg_set_buf(&dd->in_sgl[nsg - 1], buf_in, clen);
>> +	}
>>  
>>  	dd->in_sg = dd->in_sgl;
>>  	dd->total = clen;
>> @@ -258,6 +264,8 @@ 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;
>> @@ -270,6 +278,12 @@ static int omap_aes_gcm_crypt(struct aead_request *req, unsigned long mode)
>>  	if (err)
>>  		return err;
>>  
>> +	if (req->assoclen + req->cryptlen == 0) {
>> +		scatterwalk_map_and_copy(ctx->auth_tag, req->dst, 0, authlen,
>> +					 1);
>> +		return 0;
>> +	}
>> +
>>  	dd = omap_aes_find_dev(ctx);
>>  	if (!dd)
>>  		return -ENODEV;
>> -- 
>> 1.7.9.5
>>
>> --
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>