Commit 1a098379 authored by Harsh Jain's avatar Harsh Jain Committed by Herbert Xu
Browse files

crypto: xilinx-trng - Add CTR_DRBG DF processing of seed 



Versal TRNG IP does not support Derivation Function (DF) of seed.
Add DF processing for CTR_DRBG mode.

Signed-off-by: default avatarHarsh Jain <h.jain@amd.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent ba0570bd

drivers/crypto/xilinx/xilinx-trng.c

+31 −6
Original line number Diff line number Diff line
@@ -8,7 +8,6 @@ 
#include <linux/clk.h>

#include <linux/crypto.h>

#include <linux/delay.h>

#include <linux/errno.h>

#include <linux/firmware/xlnx-zynqmp.h>

#include <linux/hw_random.h>

#include <linux/io.h>
@@ -18,10 +17,11 @@ 
#include <linux/mutex.h>

#include <linux/mod_devicetable.h>

#include <linux/platform_device.h>

#include <linux/string.h>

#include <crypto/aes.h>

#include <crypto/df_sp80090a.h>

#include <crypto/internal/drbg.h>

#include <crypto/internal/cipher.h>

#include <crypto/internal/rng.h>

#include <crypto/aes.h>



/* TRNG Registers Offsets */

#define TRNG_STATUS_OFFSET			0x4U
@@ -59,6 +59,8 @@ 
struct xilinx_rng {

	void __iomem *rng_base;

	struct device *dev;

	unsigned char *scratchpadbuf;

	struct crypto_aes_ctx *aesctx;

	struct mutex lock;	/* Protect access to TRNG device */

	struct hwrng trng;

};
@@ -182,9 +184,13 @@ static void xtrng_enable_entropy(struct xilinx_rng *rng) 
static int xtrng_reseed_internal(struct xilinx_rng *rng)

{

	u8 entropy[TRNG_ENTROPY_SEED_LEN_BYTES];

	struct drbg_string data;

	LIST_HEAD(seedlist);

	u32 val;

	int ret;



	drbg_string_fill(&data, entropy, TRNG_SEED_LEN_BYTES);

	list_add_tail(&data.list, &seedlist);

	memset(entropy, 0, sizeof(entropy));

	xtrng_enable_entropy(rng);
@@ -192,9 +198,14 @@ static int xtrng_reseed_internal(struct xilinx_rng *rng) 
	ret = xtrng_collect_random_data(rng, entropy, TRNG_SEED_LEN_BYTES, true);

	if (ret != TRNG_SEED_LEN_BYTES)

		return -EINVAL;

	ret = crypto_drbg_ctr_df(rng->aesctx, rng->scratchpadbuf,

				 TRNG_SEED_LEN_BYTES, &seedlist, AES_BLOCK_SIZE,

				 TRNG_SEED_LEN_BYTES);

	if (ret)

		return ret;



	xtrng_write_multiple_registers(rng->rng_base + TRNG_EXT_SEED_OFFSET,

				       (u32 *)entropy, TRNG_NUM_INIT_REGS);

				       (u32 *)rng->scratchpadbuf, TRNG_NUM_INIT_REGS);

	/* select reseed operation */

	iowrite32(TRNG_CTRL_PRNGXS_MASK, rng->rng_base + TRNG_CTRL_OFFSET);
@@ -324,6 +335,7 @@ static void xtrng_hwrng_unregister(struct hwrng *trng) 
static int xtrng_probe(struct platform_device *pdev)

{

	struct xilinx_rng *rng;

	size_t sb_size;

	int ret;



	rng = devm_kzalloc(&pdev->dev, sizeof(*rng), GFP_KERNEL);
@@ -337,11 +349,22 @@ static int xtrng_probe(struct platform_device *pdev) 
		return PTR_ERR(rng->rng_base);

	}



	rng->aesctx = devm_kzalloc(&pdev->dev, sizeof(*rng->aesctx), GFP_KERNEL);

	if (!rng->aesctx)

		return -ENOMEM;



	sb_size = crypto_drbg_ctr_df_datalen(TRNG_SEED_LEN_BYTES, AES_BLOCK_SIZE);

	rng->scratchpadbuf = devm_kzalloc(&pdev->dev, sb_size, GFP_KERNEL);

	if (!rng->scratchpadbuf) {

		ret = -ENOMEM;

		goto end;

	}



	xtrng_trng_reset(rng->rng_base);

	ret = xtrng_reseed_internal(rng);

	if (ret) {

		dev_err(&pdev->dev, "TRNG Seed fail\n");

		return ret;

		goto end;

	}



	xilinx_rng_dev = rng;
@@ -349,8 +372,9 @@ static int xtrng_probe(struct platform_device *pdev) 
	ret = crypto_register_rng(&xtrng_trng_alg);

	if (ret) {

		dev_err(&pdev->dev, "Crypto Random device registration failed: %d\n", ret);

		return ret;

		goto end;

	}



	ret = xtrng_hwrng_register(&rng->trng);

	if (ret) {

		dev_err(&pdev->dev, "HWRNG device registration failed: %d\n", ret);
@@ -363,6 +387,7 @@ static int xtrng_probe(struct platform_device *pdev) 
crypto_rng_free:

	crypto_unregister_rng(&xtrng_trng_alg);



end:

	return ret;

}