RE: [EXT] Re: [PATCH] crypto: caam/jr - fix Chacha20 + Poly1305 self test failure

[Gaurav Jain]

Hi Eric

> -----Original Message-----
> From: Eric Biggers <ebiggers@xxxxxxxxxx>
> Sent: Friday, September 22, 2023 8:11 AM
> To: Gaurav Jain <gaurav.jain@xxxxxxx>
> Cc: Horia Geanta <horia.geanta@xxxxxxx>; Pankaj Gupta
> <pankaj.gupta@xxxxxxx>; Varun Sethi <V.Sethi@xxxxxxx>; Meenakshi
> Aggarwal <meenakshi.aggarwal@xxxxxxx>; Herbert Xu
> <herbert@xxxxxxxxxxxxxxxxxxx>; David S . Miller <davem@xxxxxxxxxxxxx>;
> Aisheng Dong <aisheng.dong@xxxxxxx>; Silvano Di Ninno
> <silvano.dininno@xxxxxxx>; linux-crypto@xxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx; dl-linux-imx <linux-imx@xxxxxxx>
> Subject: [EXT] Re: [PATCH] crypto: caam/jr - fix Chacha20 + Poly1305 self test
> failure
> 
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> 
> On Thu, Sep 21, 2023 at 06:12:37PM +0530, Gaurav Jain wrote:
> > key buffer is not copied in chachapoly_setkey function, results in
> > wrong output for encryption/decryption operation.
> >
> > fix this by memcpy the key in caam_ctx key arrary
> >
> > Fixes: d6bbd4eea243 ("crypto: caam/jr - add support for Chacha20 +
> > Poly1305")
> > Signed-off-by: Gaurav Jain <gaurav.jain@xxxxxxx>
> > ---
> >  drivers/crypto/caam/caamalg.c | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/crypto/caam/caamalg.c
> > b/drivers/crypto/caam/caamalg.c index eba2d750c3b0..066f08a3a040
> > 100644
> > --- a/drivers/crypto/caam/caamalg.c
> > +++ b/drivers/crypto/caam/caamalg.c
> > @@ -575,7 +575,8 @@ static int chachapoly_setkey(struct crypto_aead *aead,
> const u8 *key,
> >       if (keylen != CHACHA_KEY_SIZE + saltlen)
> >               return -EINVAL;
> >
> > -     ctx->cdata.key_virt = key;
> > +     memcpy(ctx->key, key, keylen);
> > +     ctx->cdata.key_virt = ctx->key;
> >       ctx->cdata.keylen = keylen - saltlen;
> >
> 
> Huh, so this driver just ignored the key?  Is anyone using the ChaCha20Poly1305
> support in this driver?  Based on this bug existing, that seems unlikely.  If that's
> the case, wouldn't it be better just to remove the ChaCha20Poly1305 support
> from this driver so that the code doesn't need to be maintained?

This algorithm is used in IPSEC and we are also going to use ChaCha20Poly1305 support for Kernel TLS.
Gaurav
> 
> - Eric