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	ecdsa_set_pub_key() makes an u64 pointer at 1 byte offset of the key.
This results in an unaligned u64 pointer. This pointer is passed to
ecc_swap_digits() which assumes natural alignment.
This causes a kernel crash on an armv7 platform:
[    0.409022] Unhandled fault: alignment exception (0x001) at 0xc2a0a6a9
...
[    0.416982] PC is at ecdsa_set_pub_key+0xdc/0x120
...
[    0.491492] Backtrace:
[    0.492059] [<c07c266c>] (ecdsa_set_pub_key) from [<c07c75d4>] (test_akcipher_one+0xf4/0x6c0)
Handle unaligned input buffer in ecc_swap_digits() by replacing
be64_to_cpu() to get_unaligned_be64(). Change type of in pointer to
void to reflect it doesn’t necessarily need to be aligned.
Fixes: 4e6602916b ("crypto: ecdsa - Add support for ECDSA signature verification")
Reported-by: Guillaume Gardet <guillaume.gardet@arm.com>
Suggested-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Mian Yousaf Kaukab <ykaukab@suse.de>
Tested-by: Stefan Berger <stefanb@linux.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
		
	
			
		
			
				
	
	
		
			246 lines
		
	
	
		
			7.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			246 lines
		
	
	
		
			7.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * Copyright (c) 2013, Kenneth MacKay
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 * All rights reserved.
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 *
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 * Redistribution and use in source and binary forms, with or without
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 * modification, are permitted provided that the following conditions are
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 * met:
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 *  * Redistributions of source code must retain the above copyright
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 *   notice, this list of conditions and the following disclaimer.
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 *  * Redistributions in binary form must reproduce the above copyright
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 *    notice, this list of conditions and the following disclaimer in the
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 *    documentation and/or other materials provided with the distribution.
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 *
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 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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 * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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 */
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#ifndef _CRYPTO_ECC_H
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#define _CRYPTO_ECC_H
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#include <crypto/ecc_curve.h>
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#include <asm/unaligned.h>
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/* One digit is u64 qword. */
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#define ECC_CURVE_NIST_P192_DIGITS  3
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#define ECC_CURVE_NIST_P256_DIGITS  4
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#define ECC_CURVE_NIST_P384_DIGITS  6
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#define ECC_MAX_DIGITS              (512 / 64) /* due to ecrdsa */
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#define ECC_DIGITS_TO_BYTES_SHIFT 3
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#define ECC_MAX_BYTES (ECC_MAX_DIGITS << ECC_DIGITS_TO_BYTES_SHIFT)
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#define ECC_POINT_INIT(x, y, ndigits)	(struct ecc_point) { x, y, ndigits }
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/**
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 * ecc_swap_digits() - Copy ndigits from big endian array to native array
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 * @in:       Input array
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 * @out:      Output array
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 * @ndigits:  Number of digits to copy
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 */
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static inline void ecc_swap_digits(const void *in, u64 *out, unsigned int ndigits)
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{
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	const __be64 *src = (__force __be64 *)in;
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	int i;
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	for (i = 0; i < ndigits; i++)
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		out[i] = get_unaligned_be64(&src[ndigits - 1 - i]);
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}
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/**
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 * ecc_is_key_valid() - Validate a given ECDH private key
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 *
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 * @curve_id:		id representing the curve to use
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 * @ndigits:		curve's number of digits
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 * @private_key:	private key to be used for the given curve
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 * @private_key_len:	private key length
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 *
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 * Returns 0 if the key is acceptable, a negative value otherwise
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 */
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int ecc_is_key_valid(unsigned int curve_id, unsigned int ndigits,
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		     const u64 *private_key, unsigned int private_key_len);
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/**
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 * ecc_gen_privkey() -  Generates an ECC private key.
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 * The private key is a random integer in the range 0 < random < n, where n is a
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 * prime that is the order of the cyclic subgroup generated by the distinguished
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 * point G.
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 * @curve_id:		id representing the curve to use
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 * @ndigits:		curve number of digits
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 * @private_key:	buffer for storing the generated private key
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 *
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 * Returns 0 if the private key was generated successfully, a negative value
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 * if an error occurred.
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 */
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int ecc_gen_privkey(unsigned int curve_id, unsigned int ndigits, u64 *privkey);
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/**
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 * ecc_make_pub_key() - Compute an ECC public key
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 *
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 * @curve_id:		id representing the curve to use
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 * @ndigits:		curve's number of digits
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 * @private_key:	pregenerated private key for the given curve
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 * @public_key:		buffer for storing the generated public key
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 *
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 * Returns 0 if the public key was generated successfully, a negative value
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 * if an error occurred.
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 */
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int ecc_make_pub_key(const unsigned int curve_id, unsigned int ndigits,
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		     const u64 *private_key, u64 *public_key);
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/**
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 * crypto_ecdh_shared_secret() - Compute a shared secret
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 *
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 * @curve_id:		id representing the curve to use
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 * @ndigits:		curve's number of digits
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 * @private_key:	private key of part A
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 * @public_key:		public key of counterpart B
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 * @secret:		buffer for storing the calculated shared secret
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 *
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 * Note: It is recommended that you hash the result of crypto_ecdh_shared_secret
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 * before using it for symmetric encryption or HMAC.
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 *
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 * Returns 0 if the shared secret was generated successfully, a negative value
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 * if an error occurred.
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 */
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int crypto_ecdh_shared_secret(unsigned int curve_id, unsigned int ndigits,
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			      const u64 *private_key, const u64 *public_key,
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			      u64 *secret);
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/**
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 * ecc_is_pubkey_valid_partial() - Partial public key validation
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 *
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 * @curve:		elliptic curve domain parameters
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 * @pk:			public key as a point
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 *
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 * Valdiate public key according to SP800-56A section 5.6.2.3.4 ECC Partial
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 * Public-Key Validation Routine.
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 *
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 * Note: There is no check that the public key is in the correct elliptic curve
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 * subgroup.
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 *
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 * Return: 0 if validation is successful, -EINVAL if validation is failed.
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 */
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int ecc_is_pubkey_valid_partial(const struct ecc_curve *curve,
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				struct ecc_point *pk);
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/**
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 * ecc_is_pubkey_valid_full() - Full public key validation
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 *
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 * @curve:		elliptic curve domain parameters
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 * @pk:			public key as a point
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 *
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 * Valdiate public key according to SP800-56A section 5.6.2.3.3 ECC Full
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 * Public-Key Validation Routine.
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 *
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 * Return: 0 if validation is successful, -EINVAL if validation is failed.
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 */
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int ecc_is_pubkey_valid_full(const struct ecc_curve *curve,
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			     struct ecc_point *pk);
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/**
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 * vli_is_zero() - Determine is vli is zero
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 *
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 * @vli:		vli to check.
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 * @ndigits:		length of the @vli
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 */
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bool vli_is_zero(const u64 *vli, unsigned int ndigits);
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/**
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 * vli_cmp() - compare left and right vlis
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 *
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 * @left:		vli
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 * @right:		vli
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 * @ndigits:		length of both vlis
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 *
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 * Returns sign of @left - @right, i.e. -1 if @left < @right,
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 * 0 if @left == @right, 1 if @left > @right.
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 */
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int vli_cmp(const u64 *left, const u64 *right, unsigned int ndigits);
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/**
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 * vli_sub() - Subtracts right from left
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 *
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 * @result:		where to write result
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 * @left:		vli
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 * @right		vli
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 * @ndigits:		length of all vlis
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 *
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 * Note: can modify in-place.
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 *
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 * Return: carry bit.
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 */
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u64 vli_sub(u64 *result, const u64 *left, const u64 *right,
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	    unsigned int ndigits);
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/**
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 * vli_from_be64() - Load vli from big-endian u64 array
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 *
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 * @dest:		destination vli
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 * @src:		source array of u64 BE values
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 * @ndigits:		length of both vli and array
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 */
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void vli_from_be64(u64 *dest, const void *src, unsigned int ndigits);
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/**
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 * vli_from_le64() - Load vli from little-endian u64 array
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 *
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 * @dest:		destination vli
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 * @src:		source array of u64 LE values
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 * @ndigits:		length of both vli and array
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 */
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void vli_from_le64(u64 *dest, const void *src, unsigned int ndigits);
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/**
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 * vli_mod_inv() - Modular inversion
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 *
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 * @result:		where to write vli number
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 * @input:		vli value to operate on
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 * @mod:		modulus
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 * @ndigits:		length of all vlis
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 */
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void vli_mod_inv(u64 *result, const u64 *input, const u64 *mod,
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		 unsigned int ndigits);
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/**
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 * vli_mod_mult_slow() - Modular multiplication
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 *
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 * @result:		where to write result value
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 * @left:		vli number to multiply with @right
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 * @right:		vli number to multiply with @left
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 * @mod:		modulus
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 * @ndigits:		length of all vlis
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 *
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 * Note: Assumes that mod is big enough curve order.
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 */
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void vli_mod_mult_slow(u64 *result, const u64 *left, const u64 *right,
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		       const u64 *mod, unsigned int ndigits);
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/**
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 * ecc_point_mult_shamir() - Add two points multiplied by scalars
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 *
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 * @result:		resulting point
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 * @x:			scalar to multiply with @p
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 * @p:			point to multiply with @x
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 * @y:			scalar to multiply with @q
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 * @q:			point to multiply with @y
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 * @curve:		curve
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 *
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 * Returns result = x * p + x * q over the curve.
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 * This works faster than two multiplications and addition.
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 */
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void ecc_point_mult_shamir(const struct ecc_point *result,
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			   const u64 *x, const struct ecc_point *p,
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			   const u64 *y, const struct ecc_point *q,
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			   const struct ecc_curve *curve);
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#endif
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