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authorIuliana Prodan <iuliana.prodan@nxp.com>2019-05-28 12:52:10 +0300
committerDaniel Thompson <daniel@redfelineninja.org.uk>2019-09-17 16:03:04 +0100
commitb7379d5ce5d61f4e6f3b411820416007a700682f (patch)
treec474930ad241bb71f08629cf1560c39032cde4f3
parent492ac1b512d62fe7efc315711bfdeadc5b7a0bc4 (diff)
downloadlinux-b7379d5ce5d61f4e6f3b411820416007a700682f.tar.gz
crypto: caam - fix pkcs1pad(rsa-caam, sha256) failure because of invalid input
The problem is with the input data size sent to CAAM for encrypt/decrypt. Pkcs1pad is failing due to pkcs1 padding done in SW starting with0x01 instead of 0x00 0x01. CAAM expects an input of modulus size. For this we strip the leading zeros in case the size is more than modulus or pad the input with zeros until the modulus size is reached. Signed-off-by: Iuliana Prodan <iuliana.prodan@nxp.com> Reviewed-by: Horia Geantă <horia.geanta@nxp.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> (cherry picked from commit c3725f7ccc8cae1fb71e97768f03bfbd846f7827) Backported to dash-linux. Signed-off-by: Horia Geantă <horia.geanta@nxp.com>
-rw-r--r--drivers/crypto/caam/caampkc.c87
-rw-r--r--drivers/crypto/caam/caampkc.h2
2 files changed, 74 insertions, 15 deletions
diff --git a/drivers/crypto/caam/caampkc.c b/drivers/crypto/caam/caampkc.c
index d876f2344fd6..30ede9310f79 100644
--- a/drivers/crypto/caam/caampkc.c
+++ b/drivers/crypto/caam/caampkc.c
@@ -24,6 +24,10 @@
sizeof(struct rsa_priv_f2_pdb))
#define DESC_RSA_PRIV_F3_LEN (2 * CAAM_CMD_SZ + \
sizeof(struct rsa_priv_f3_pdb))
+#define CAAM_RSA_MAX_INPUT_SIZE 512 /* for a 4096-bit modulus */
+
+/* buffer filled with zeros, used for padding */
+static u8 *zero_buffer;
static void rsa_io_unmap(struct device *dev, struct rsa_edesc *edesc,
struct akcipher_request *req)
@@ -168,6 +172,13 @@ static void rsa_priv_f3_done(struct device *dev, u32 *desc, u32 err,
akcipher_request_complete(req, err);
}
+/**
+ * Count leading zeros, need it to strip, from a given scatterlist
+ *
+ * @sgl : scatterlist to count zeros from
+ * @nbytes: number of zeros, in bytes, to strip
+ * @flags : operation flags
+ */
static int caam_rsa_count_leading_zeros(struct scatterlist *sgl,
unsigned int nbytes,
unsigned int flags)
@@ -187,7 +198,8 @@ static int caam_rsa_count_leading_zeros(struct scatterlist *sgl,
lzeros = 0;
len = 0;
while (nbytes > 0) {
- while (len && !*buff) {
+ /* do not strip more than given bytes */
+ while (len && !*buff && lzeros < nbytes) {
lzeros++;
len--;
buff++;
@@ -218,6 +230,7 @@ static struct rsa_edesc *rsa_edesc_alloc(struct akcipher_request *req,
struct caam_rsa_ctx *ctx = akcipher_tfm_ctx(tfm);
struct device *dev = ctx->dev;
struct caam_rsa_req_ctx *req_ctx = akcipher_request_ctx(req);
+ struct caam_rsa_key *key = &ctx->key;
struct rsa_edesc *edesc;
gfp_t flags = (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
GFP_KERNEL : GFP_ATOMIC;
@@ -225,20 +238,38 @@ 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;
+ unsigned int diff_size = 0;
int lzeros;
- lzeros = caam_rsa_count_leading_zeros(req->src, req->src_len, sg_flags);
- if (lzeros < 0)
- return ERR_PTR(lzeros);
- req->src_len -= lzeros;
- req->src = scatterwalk_ffwd(req_ctx->src, req->src, lzeros);
+ if (req->src_len > key->n_sz) {
+ /*
+ * strip leading zeros and
+ * return the number of zeros to skip
+ */
+ lzeros = caam_rsa_count_leading_zeros(req->src, req->src_len -
+ key->n_sz, sg_flags);
+ if (lzeros < 0)
+ return ERR_PTR(lzeros);
+
+ req->src_len -= lzeros;
+ req->src = scatterwalk_ffwd(req_ctx->src, req->src, lzeros);
+ } else {
+ /*
+ * input src is less then n key modulus,
+ * so there will be zero padding
+ */
+ diff_size = key->n_sz - req->src_len;
+ }
src_nents = sg_nents_for_len(req->src, req->src_len);
dst_nents = sg_nents_for_len(req->dst, req->dst_len);
- if (src_nents > 1)
- sec4_sg_len = src_nents;
+ if (!diff_size && src_nents == 1)
+ sec4_sg_len = 0; /* no need for an input hw s/g table */
+ else
+ sec4_sg_len = src_nents + !!diff_size;
+ sec4_sg_index = sec4_sg_len;
if (dst_nents > 1)
sec4_sg_len += dst_nents;
@@ -263,12 +294,14 @@ static struct rsa_edesc *rsa_edesc_alloc(struct akcipher_request *req,
}
edesc->sec4_sg = (void *)edesc + sizeof(*edesc) + desclen;
+ if (diff_size)
+ dma_to_sec4_sg_one(edesc->sec4_sg, ctx->padding_dma, diff_size,
+ 0);
+
+ if (sec4_sg_index)
+ sg_to_sec4_sg_last(req->src, src_nents, edesc->sec4_sg +
+ !!diff_size, 0);
- sec4_sg_index = 0;
- if (src_nents > 1) {
- sg_to_sec4_sg_last(req->src, src_nents, edesc->sec4_sg, 0);
- sec4_sg_index += src_nents;
- }
if (dst_nents > 1)
sg_to_sec4_sg_last(req->dst, dst_nents,
edesc->sec4_sg + sec4_sg_index, 0);
@@ -289,6 +322,10 @@ static struct rsa_edesc *rsa_edesc_alloc(struct akcipher_request *req,
edesc->sec4_sg_bytes = sec4_sg_bytes;
+ print_hex_dump_debug("caampkc sec4_sg@" __stringify(__LINE__) ": ",
+ DUMP_PREFIX_ADDRESS, 16, 4, edesc->sec4_sg,
+ edesc->sec4_sg_bytes, 1);
+
return edesc;
sec4_sg_fail:
@@ -978,6 +1015,15 @@ static int caam_rsa_init_tfm(struct crypto_akcipher *tfm)
return PTR_ERR(ctx->dev);
}
+ ctx->padding_dma = dma_map_single(ctx->dev, zero_buffer,
+ CAAM_RSA_MAX_INPUT_SIZE - 1,
+ DMA_TO_DEVICE);
+ if (dma_mapping_error(ctx->dev, ctx->padding_dma)) {
+ dev_err(ctx->dev, "unable to map padding\n");
+ caam_jr_free(ctx->dev);
+ return -ENOMEM;
+ }
+
return 0;
}
@@ -987,6 +1033,8 @@ static void caam_rsa_exit_tfm(struct crypto_akcipher *tfm)
struct caam_rsa_ctx *ctx = akcipher_tfm_ctx(tfm);
struct caam_rsa_key *key = &ctx->key;
+ dma_unmap_single(ctx->dev, ctx->padding_dma, CAAM_RSA_MAX_INPUT_SIZE -
+ 1, DMA_TO_DEVICE);
caam_rsa_free_key(key);
caam_jr_free(ctx->dev);
}
@@ -1029,17 +1077,26 @@ int caam_pkc_init(struct device *ctrldev)
if (!pk_inst)
return 0;
+ /* allocate zero buffer, used for padding input */
+ zero_buffer = kzalloc(CAAM_RSA_MAX_INPUT_SIZE - 1, GFP_DMA |
+ GFP_KERNEL);
+ if (!zero_buffer)
+ return -ENOMEM;
+
err = crypto_register_akcipher(&caam_rsa);
- if (err)
+ if (err) {
+ kfree(zero_buffer);
dev_warn(ctrldev, "%s alg registration failed\n",
caam_rsa.base.cra_driver_name);
- else
+ } else {
dev_info(ctrldev, "caam pkc algorithms registered in /proc/crypto\n");
+ }
return err;
}
void caam_pkc_exit(void)
{
+ kfree(zero_buffer);
crypto_unregister_akcipher(&caam_rsa);
}
diff --git a/drivers/crypto/caam/caampkc.h b/drivers/crypto/caam/caampkc.h
index 82645bcf8b27..5ac72015eba5 100644
--- a/drivers/crypto/caam/caampkc.h
+++ b/drivers/crypto/caam/caampkc.h
@@ -89,10 +89,12 @@ struct caam_rsa_key {
* caam_rsa_ctx - per session context.
* @key : RSA key in DMA zone
* @dev : device structure
+ * @padding_dma : dma address of padding, for adding it to the input
*/
struct caam_rsa_ctx {
struct caam_rsa_key key;
struct device *dev;
+ dma_addr_t padding_dma;
};
/**