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-rw-r--r--drivers/crypto/caam/caampkc.c89
-rw-r--r--drivers/crypto/caam/caampkc.h2
2 files changed, 74 insertions, 17 deletions
diff --git a/drivers/crypto/caam/caampkc.c b/drivers/crypto/caam/caampkc.c
index 34e37f9bd828..2bd3a17fd4da 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;
@@ -225,21 +238,37 @@ 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 += pad_sg_nents(dst_nents);
else
@@ -266,12 +295,14 @@ 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);
@@ -292,6 +323,10 @@ 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:
@@ -981,6 +1016,15 @@ 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;
}
@@ -990,6 +1034,8 @@ 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);
}
@@ -1030,17 +1076,26 @@ 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;
};
/**