| Message ID | 1523790224-26083-1-git-send-email-festevam@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Herbert Xu |
| Headers | show |
On Sun, Apr 15, 2018 at 12:03 PM, Fabio Estevam <festevam@gmail.com> wrote: > From: Fabio Estevam <fabio.estevam@nxp.com> > > imx6ul and imx7 report the following error: > > caam_jr 2142000.jr1: 40000789: DECO: desc idx 7: > Protocol Size Error - A protocol has seen an error in size. When > running RSA, pdb size N < (size of F) when no formatting is used; or > pdb size N < (F + 11) when formatting is used. > > ------------[ cut here ]------------ > WARNING: CPU: 0 PID: 1 at crypto/asymmetric_keys/public_key.c:148 > public_key_verify_signature+0x27c/0x2b0 > > This error happens because the signature contains 257 bytes, including > a leading zero as the first element. > > Fix the problem by stripping off the leading zero from input data > before feeding it to the CAAM accelerator. > > Fixes: 8c419778ab57e497b5 ("crypto: caam - add support for RSA algorithm") > Cc: <stable@vger.kernel.org> > Reported-by: Martin Townsend <mtownsend1973@gmail.com> > Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com> > --- > Changes since v1: > - Use a temp pointer > - Assign len to req->src_len , so that more than one leading zero > can be taken into account > > drivers/crypto/caam/caampkc.c | 45 +++++++++++++++++++++++++++++++++++-------- > 1 file changed, 37 insertions(+), 8 deletions(-) > > diff --git a/drivers/crypto/caam/caampkc.c b/drivers/crypto/caam/caampkc.c > index 7a897209..5f3e627 100644 > --- a/drivers/crypto/caam/caampkc.c > +++ b/drivers/crypto/caam/caampkc.c > @@ -166,6 +166,14 @@ static void rsa_priv_f3_done(struct device *dev, u32 *desc, u32 err, > akcipher_request_complete(req, err); > } > > +static void caam_rsa_drop_leading_zeros(const u8 **ptr, size_t *nbytes) > +{ > + while (!**ptr && *nbytes) { > + (*ptr)++; > + (*nbytes)--; > + } > +} > + > static struct rsa_edesc *rsa_edesc_alloc(struct akcipher_request *req, > size_t desclen) > { > @@ -178,7 +186,36 @@ static struct rsa_edesc *rsa_edesc_alloc(struct akcipher_request *req, > int sgc; > int sec4_sg_index, sec4_sg_len = 0, sec4_sg_bytes; > int src_nents, dst_nents; > + const u8 *temp; > + void *buffer; > + size_t len; > + > + buffer = kzalloc(req->src_len, GFP_ATOMIC); > + if (!buffer) > + return ERR_PTR(-ENOMEM); > + > + sg_copy_to_buffer(req->src, sg_nents(req->src), > + buffer, req->src_len); > + temp = (u8 *)buffer; > + len = req->src_len; > > + /* > + * Check if the buffer contains leading zeros and if > + * it does, drop the leading zeros > + */ > + if (temp[0] == 0) { > + caam_rsa_drop_leading_zeros(&temp, &len); Sorry to be a pain but looking at the other use cases for caam_rsa_drop_leading_zeros they check len afterwards which makes more sense to me as temp being NULL after this operation is very unlikely :) and I suppose we are trying to catch the case where the data is all zeroes which wouldn't be a valid signature. > + if (!temp) { > + kfree(buffer); > + return ERR_PTR(-ENOMEM); > + } > + > + req->src_len = len; > + sg_copy_from_buffer(req->src, sg_nents(req->src), > + (void *)temp, req->src_len); > + } > + > + kfree(buffer); > src_nents = sg_nents_for_len(req->src, req->src_len); > dst_nents = sg_nents_for_len(req->dst, req->dst_len); > > @@ -683,14 +720,6 @@ static void caam_rsa_free_key(struct caam_rsa_key *key) > memset(key, 0, sizeof(*key)); > } > > -static void caam_rsa_drop_leading_zeros(const u8 **ptr, size_t *nbytes) > -{ > - while (!**ptr && *nbytes) { > - (*ptr)++; > - (*nbytes)--; > - } > -} > - > /** > * caam_read_rsa_crt - Used for reading dP, dQ, qInv CRT members. > * dP, dQ and qInv could decode to less than corresponding p, q length, as the > -- > 2.7.4 >
On Sun, Apr 15, 2018 at 10:52 AM, Martin Townsend <mtownsend1973@gmail.com> wrote: > Sorry to be a pain but looking at the other use cases for > caam_rsa_drop_leading_zeros they check len afterwards which makes more > sense to me as temp being NULL after this operation is very unlikely > :) and I suppose we are trying to catch the case where the data is all > zeroes which wouldn't be a valid signature. You are right. I have just sent a v3 that checks len after caam_rsa_drop_leading_zeros(). Thanks
diff --git a/drivers/crypto/caam/caampkc.c b/drivers/crypto/caam/caampkc.c index 7a897209..5f3e627 100644 --- a/drivers/crypto/caam/caampkc.c +++ b/drivers/crypto/caam/caampkc.c @@ -166,6 +166,14 @@ static void rsa_priv_f3_done(struct device *dev, u32 *desc, u32 err, akcipher_request_complete(req, err); } +static void caam_rsa_drop_leading_zeros(const u8 **ptr, size_t *nbytes) +{ + while (!**ptr && *nbytes) { + (*ptr)++; + (*nbytes)--; + } +} + static struct rsa_edesc *rsa_edesc_alloc(struct akcipher_request *req, size_t desclen) { @@ -178,7 +186,36 @@ static struct rsa_edesc *rsa_edesc_alloc(struct akcipher_request *req, int sgc; int sec4_sg_index, sec4_sg_len = 0, sec4_sg_bytes; int src_nents, dst_nents; + const u8 *temp; + void *buffer; + size_t len; + + buffer = kzalloc(req->src_len, GFP_ATOMIC); + if (!buffer) + return ERR_PTR(-ENOMEM); + + sg_copy_to_buffer(req->src, sg_nents(req->src), + buffer, req->src_len); + temp = (u8 *)buffer; + len = req->src_len; + /* + * Check if the buffer contains leading zeros and if + * it does, drop the leading zeros + */ + if (temp[0] == 0) { + caam_rsa_drop_leading_zeros(&temp, &len); + if (!temp) { + kfree(buffer); + return ERR_PTR(-ENOMEM); + } + + req->src_len = len; + sg_copy_from_buffer(req->src, sg_nents(req->src), + (void *)temp, req->src_len); + } + + kfree(buffer); src_nents = sg_nents_for_len(req->src, req->src_len); dst_nents = sg_nents_for_len(req->dst, req->dst_len); @@ -683,14 +720,6 @@ static void caam_rsa_free_key(struct caam_rsa_key *key) memset(key, 0, sizeof(*key)); } -static void caam_rsa_drop_leading_zeros(const u8 **ptr, size_t *nbytes) -{ - while (!**ptr && *nbytes) { - (*ptr)++; - (*nbytes)--; - } -} - /** * caam_read_rsa_crt - Used for reading dP, dQ, qInv CRT members. * dP, dQ and qInv could decode to less than corresponding p, q length, as the