now rsa

config RSA

	bool "Use RSA Library"

	select RSA_FREESCALE_EXP if FSL_CAAM && !ARCH_MX7 && !ARCH_MX6 && !ARCH_MX5

	select RSA_SOFTWARE_EXP if !RSA_FREESCALE_EXP

	help

	  RSA support. This enables the RSA algorithm used for FIT image

	  verification in U-Boot.

	  See doc/uImage.FIT/signature.txt for more details.

	  The Modular Exponentiation algorithm in RSA is implemented using

	  driver model. So CONFIG_DM needs to be enabled by default for this

	  library to function.

	  The signing part is build into mkimage regardless of this

	  option. The software based modular exponentiation is built into

	  mkimage irrespective of this option.

if RSA

config SPL_RSA

	bool "Use RSA Library within SPL"

config RSA_SOFTWARE_EXP

	bool "Enable driver for RSA Modular Exponentiation in software"

	depends on DM

	help

	  Enables driver for modular exponentiation in software. This is a RSA

	  algorithm used in FIT image verification. It required RSA Key as

	  input.

	  See doc/uImage.FIT/signature.txt for more details.

config RSA_FREESCALE_EXP

	bool "Enable RSA Modular Exponentiation with FSL crypto accelerator"

	depends on DM && FSL_CAAM && !ARCH_MX7 && !ARCH_MX6 && !ARCH_MX5

	help

	Enables driver for RSA modular exponentiation using Freescale cryptographic

	accelerator - CAAM.

endif

# SPDX-License-Identifier: GPL-2.0+

#

# Copyright (c) 2013, Google Inc.

#

# (C) Copyright 2000-2007

# Wolfgang Denk, DENX Software Engineering, wd@denx.de.

obj-$(CONFIG_$(SPL_)FIT_SIGNATURE) += rsa-verify.o rsa-checksum.o

obj-$(CONFIG_RSA_SOFTWARE_EXP) += rsa-mod-exp.o

// SPDX-License-Identifier: GPL-2.0+

/*

 * Copyright (c) 2013, Andreas Oetken.

 */

#ifndef USE_HOSTCC

#include <common.h>

#include <fdtdec.h>

#include <asm/byteorder.h>

#include <linux/errno.h>

#include <asm/unaligned.h>

#include <hash.h>

#else

#include "fdt_host.h"

#endif

#include <u-boot/rsa.h>

int hash_calculate(const char *name,

		    const struct image_region region[],

		    int region_count, uint8_t *checksum)

{

	struct hash_algo *algo;

	int ret = 0;

	void *ctx;

	uint32_t i;

	i = 0;

	ret = hash_progressive_lookup_algo(name, &algo);

	if (ret)

		return ret;

	ret = algo->hash_init(algo, &ctx);

	if (ret)

		return ret;

	for (i = 0; i < region_count - 1; i++) {

		ret = algo->hash_update(algo, ctx, region[i].data,

					region[i].size, 0);

		if (ret)

			return ret;

	}

	ret = algo->hash_update(algo, ctx, region[i].data, region[i].size, 1);

	if (ret)

		return ret;

	ret = algo->hash_finish(algo, ctx, checksum, algo->digest_size);

	if (ret)

		return ret;

	return 0;

}

// SPDX-License-Identifier: GPL-2.0+

/*

 * Copyright (c) 2013, Google Inc.

 */

#ifndef USE_HOSTCC

#include <common.h>

#include <fdtdec.h>

#include <asm/types.h>

#include <asm/byteorder.h>

#include <linux/errno.h>

#include <asm/types.h>

#include <asm/unaligned.h>

#else

#include "fdt_host.h"

#include "mkimage.h"

#include <fdt_support.h>

#endif

#include <u-boot/rsa.h>

#include <u-boot/rsa-mod-exp.h>

#define UINT64_MULT32(v, multby)  (((uint64_t)(v)) * ((uint32_t)(multby)))

#define get_unaligned_be32(a) fdt32_to_cpu(*(uint32_t *)a)

#define put_unaligned_be32(a, b) (*(uint32_t *)(b) = cpu_to_fdt32(a))

/* Default public exponent for backward compatibility */

#define RSA_DEFAULT_PUBEXP	65537

/**

 * subtract_modulus() - subtract modulus from the given value

 *

 * @key:	Key containing modulus to subtract

 * @num:	Number to subtract modulus from, as little endian word array

 */

static void subtract_modulus(const struct rsa_public_key *key, uint32_t num[])

{

	int64_t acc = 0;

	uint i;

	for (i = 0; i < key->len; i++) {

		acc += (uint64_t)num[i] - key->modulus[i];

		num[i] = (uint32_t)acc;

		acc >>= 32;

	}

}

/**

 * greater_equal_modulus() - check if a value is >= modulus

 *

 * @key:	Key containing modulus to check

 * @num:	Number to check against modulus, as little endian word array

 * @return 0 if num < modulus, 1 if num >= modulus

 */

static int greater_equal_modulus(const struct rsa_public_key *key,

				 uint32_t num[])

{

	int i;

	for (i = (int)key->len - 1; i >= 0; i--) {

		if (num[i] < key->modulus[i])

			return 0;

		if (num[i] > key->modulus[i])

			return 1;

	}

	return 1;  /* equal */

}

/**

 * montgomery_mul_add_step() - Perform montgomery multiply-add step

 *

 * Operation: montgomery result[] += a * b[] / n0inv % modulus

 *

 * @key:	RSA key

 * @result:	Place to put result, as little endian word array

 * @a:		Multiplier

 * @b:		Multiplicand, as little endian word array

 */

static void montgomery_mul_add_step(const struct rsa_public_key *key,

		uint32_t result[], const uint32_t a, const uint32_t b[])

{

	uint64_t acc_a, acc_b;

	uint32_t d0;

	uint i;

	acc_a = (uint64_t)a * b[0] + result[0];

	d0 = (uint32_t)acc_a * key->n0inv;

	acc_b = (uint64_t)d0 * key->modulus[0] + (uint32_t)acc_a;

	for (i = 1; i < key->len; i++) {

		acc_a = (acc_a >> 32) + (uint64_t)a * b[i] + result[i];

		acc_b = (acc_b >> 32) + (uint64_t)d0 * key->modulus[i] +

				(uint32_t)acc_a;

		result[i - 1] = (uint32_t)acc_b;

	}

	acc_a = (acc_a >> 32) + (acc_b >> 32);

	result[i - 1] = (uint32_t)acc_a;

	if (acc_a >> 32)

		subtract_modulus(key, result);

}

/**

 * montgomery_mul() - Perform montgomery mutitply

 *

 * Operation: montgomery result[] = a[] * b[] / n0inv % modulus

 *

 * @key:	RSA key

 * @result:	Place to put result, as little endian word array

 * @a:		Multiplier, as little endian word array

 * @b:		Multiplicand, as little endian word array

 */

static void montgomery_mul(const struct rsa_public_key *key,

		uint32_t result[], uint32_t a[], const uint32_t b[])

{

	uint i;

	for (i = 0; i < key->len; ++i)

		result[i] = 0;

	for (i = 0; i < key->len; ++i)

		montgomery_mul_add_step(key, result, a[i], b);

}

/**

 * num_pub_exponent_bits() - Number of bits in the public exponent

 *

 * @key:	RSA key

 * @num_bits:	Storage for the number of public exponent bits

 */

static int num_public_exponent_bits(const struct rsa_public_key *key,

		int *num_bits)

{

	uint64_t exponent;

	int exponent_bits;

	const uint max_bits = (sizeof(exponent) * 8);

	exponent = key->exponent;

	exponent_bits = 0;

	if (!exponent) {

		*num_bits = exponent_bits;

		return 0;

	}

	for (exponent_bits = 1; exponent_bits < max_bits + 1; ++exponent_bits)

		if (!(exponent >>= 1)) {

			*num_bits = exponent_bits;

			return 0;

		}

	return -EINVAL;

}

/**

 * is_public_exponent_bit_set() - Check if a bit in the public exponent is set

 *

 * @key:	RSA key

 * @pos:	The bit position to check

 */

static int is_public_exponent_bit_set(const struct rsa_public_key *key,

		int pos)

{

	return key->exponent & (1ULL << pos);

}

/**

 * pow_mod() - in-place public exponentiation

 *

 * @key:	RSA key

 * @inout:	Big-endian word array containing value and result

 */

static int pow_mod(const struct rsa_public_key *key, uint32_t *inout)

{

	uint32_t *result, *ptr;

	uint i;

	int j, k;

	/* Sanity check for stack size - key->len is in 32-bit words */

	if (key->len > RSA_MAX_KEY_BITS / 32) {

		debug("RSA key words %u exceeds maximum %d\n", key->len,

		      RSA_MAX_KEY_BITS / 32);

		return -EINVAL;

	}

	uint32_t val[key->len], acc[key->len], tmp[key->len];

	uint32_t a_scaled[key->len];

	result = tmp;  /* Re-use location. */

	/* Convert from big endian byte array to little endian word array. */

	for (i = 0, ptr = inout + key->len - 1; i < key->len; i++, ptr--)

		val[i] = get_unaligned_be32(ptr);

	if (0 != num_public_exponent_bits(key, &k))

		return -EINVAL;

	if (k < 2) {

		debug("Public exponent is too short (%d bits, minimum 2)\n",

		      k);

		return -EINVAL;

	}

	if (!is_public_exponent_bit_set(key, 0)) {

		debug("LSB of RSA public exponent must be set.\n");

		return -EINVAL;

	}

	/* the bit at e[k-1] is 1 by definition, so start with: C := M */

	montgomery_mul(key, acc, val, key->rr); /* acc = a * RR / R mod n */

	/* retain scaled version for intermediate use */

	memcpy(a_scaled, acc, key->len * sizeof(a_scaled[0]));

	for (j = k - 2; j > 0; --j) {

		montgomery_mul(key, tmp, acc, acc); /* tmp = acc^2 / R mod n */

		if (is_public_exponent_bit_set(key, j)) {

			/* acc = tmp * val / R mod n */

			montgomery_mul(key, acc, tmp, a_scaled);

		} else {

			/* e[j] == 0, copy tmp back to acc for next operation */

			memcpy(acc, tmp, key->len * sizeof(acc[0]));

		}

	}

	/* the bit at e[0] is always 1 */

	montgomery_mul(key, tmp, acc, acc); /* tmp = acc^2 / R mod n */

	montgomery_mul(key, acc, tmp, val); /* acc = tmp * a / R mod M */

	memcpy(result, acc, key->len * sizeof(result[0]));

	/* Make sure result < mod; result is at most 1x mod too large. */

	if (greater_equal_modulus(key, result))

		subtract_modulus(key, result);

	/* Convert to bigendian byte array */

	for (i = key->len - 1, ptr = inout; (int)i >= 0; i--, ptr++)

		put_unaligned_be32(result[i], ptr);

	return 0;

}

static void rsa_convert_big_endian(uint32_t *dst, const uint32_t *src, int len)

{

	int i;

	for (i = 0; i < len; i++)

		dst[i] = fdt32_to_cpu(src[len - 1 - i]);

}

int rsa_mod_exp_sw(const uint8_t *sig, uint32_t sig_len,

		struct key_prop *prop, uint8_t *out)

{

	struct rsa_public_key key;

	int ret;

	if (!prop) {

		debug("%s: Skipping invalid prop", __func__);

		return -EBADF;

	}

	key.n0inv = prop->n0inv;

	key.len = prop->num_bits;

	if (!prop->public_exponent)

		key.exponent = RSA_DEFAULT_PUBEXP;

	else

		key.exponent =

			fdt64_to_cpu(*((uint64_t *)(prop->public_exponent)));

	if (!key.len || !prop->modulus || !prop->rr) {

		debug("%s: Missing RSA key info", __func__);

		return -EFAULT;

	}

	/* Sanity check for stack size */

	if (key.len > RSA_MAX_KEY_BITS || key.len < RSA_MIN_KEY_BITS) {

		debug("RSA key bits %u outside allowed range %d..%d\n",

		      key.len, RSA_MIN_KEY_BITS, RSA_MAX_KEY_BITS);

		return -EFAULT;

	}

	key.len /= sizeof(uint32_t) * 8;

	uint32_t key1[key.len], key2[key.len];

	key.modulus = key1;

	key.rr = key2;

	rsa_convert_big_endian(key.modulus, (uint32_t *)prop->modulus, key.len);

	rsa_convert_big_endian(key.rr, (uint32_t *)prop->rr, key.len);

	if (!key.modulus || !key.rr) {

		debug("%s: Out of memory", __func__);

		return -ENOMEM;

	}

	uint32_t buf[sig_len / sizeof(uint32_t)];

	memcpy(buf, sig, sig_len);

	ret = pow_mod(&key, buf);

	if (ret)

		return ret;

	memcpy(out, buf, sig_len);

	return 0;

}

#if defined(CONFIG_CMD_ZYNQ_RSA)

/**

 * zynq_pow_mod - in-place public exponentiation

 *

 * @keyptr:	RSA key

 * @inout:	Big-endian word array containing value and result

 * @return 0 on successful calculation, otherwise failure error code

 *

 * FIXME: Use pow_mod() instead of zynq_pow_mod()

 *        pow_mod calculation required for zynq is bit different from

 *        pw_mod above here, hence defined zynq specific routine.

 */

int zynq_pow_mod(u32 *keyptr, u32 *inout)

{

	u32 *result, *ptr;

	uint i;

	struct rsa_public_key *key;

	u32 val[RSA2048_BYTES], acc[RSA2048_BYTES], tmp[RSA2048_BYTES];

	key = (struct rsa_public_key *)keyptr;

	/* Sanity check for stack size - key->len is in 32-bit words */

	if (key->len > RSA_MAX_KEY_BITS / 32) {

		debug("RSA key words %u exceeds maximum %d\n", key->len,

		      RSA_MAX_KEY_BITS / 32);

		return -EINVAL;

	}

	result = tmp;  /* Re-use location. */

	for (i = 0, ptr = inout; i < key->len; i++, ptr++)

		val[i] = *(ptr);

	montgomery_mul(key, acc, val, key->rr);  /* axx = a * RR / R mod M */

	for (i = 0; i < 16; i += 2) {

		montgomery_mul(key, tmp, acc, acc); /* tmp = acc^2 / R mod M */

		montgomery_mul(key, acc, tmp, tmp); /* acc = tmp^2 / R mod M */

	}

	montgomery_mul(key, result, acc, val);  /* result = XX * a / R mod M */

	/* Make sure result < mod; result is at most 1x mod too large. */

	if (greater_equal_modulus(key, result))

		subtract_modulus(key, result);

	for (i = 0, ptr = inout; i < key->len; i++, ptr++)

		*ptr = result[i];

	return 0;

}

#endif