1a745d3acSDaniele Alessandrelli /*
2a745d3acSDaniele Alessandrelli * Copyright (c) 2013, Kenneth MacKay
3a745d3acSDaniele Alessandrelli * All rights reserved.
4a745d3acSDaniele Alessandrelli *
5a745d3acSDaniele Alessandrelli * Redistribution and use in source and binary forms, with or without
6a745d3acSDaniele Alessandrelli * modification, are permitted provided that the following conditions are
7a745d3acSDaniele Alessandrelli * met:
8a745d3acSDaniele Alessandrelli * * Redistributions of source code must retain the above copyright
9a745d3acSDaniele Alessandrelli * notice, this list of conditions and the following disclaimer.
10a745d3acSDaniele Alessandrelli * * Redistributions in binary form must reproduce the above copyright
11a745d3acSDaniele Alessandrelli * notice, this list of conditions and the following disclaimer in the
12a745d3acSDaniele Alessandrelli * documentation and/or other materials provided with the distribution.
13a745d3acSDaniele Alessandrelli *
14a745d3acSDaniele Alessandrelli * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
15a745d3acSDaniele Alessandrelli * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
16a745d3acSDaniele Alessandrelli * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
17a745d3acSDaniele Alessandrelli * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
18a745d3acSDaniele Alessandrelli * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
19a745d3acSDaniele Alessandrelli * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
20a745d3acSDaniele Alessandrelli * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21a745d3acSDaniele Alessandrelli * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22a745d3acSDaniele Alessandrelli * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23a745d3acSDaniele Alessandrelli * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
24a745d3acSDaniele Alessandrelli * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25a745d3acSDaniele Alessandrelli */
26a745d3acSDaniele Alessandrelli #ifndef _CRYPTO_ECC_H
27a745d3acSDaniele Alessandrelli #define _CRYPTO_ECC_H
28a745d3acSDaniele Alessandrelli
29a745d3acSDaniele Alessandrelli #include <crypto/ecc_curve.h>
30a745d3acSDaniele Alessandrelli #include <asm/unaligned.h>
31a745d3acSDaniele Alessandrelli
32a745d3acSDaniele Alessandrelli /* One digit is u64 qword. */
33a745d3acSDaniele Alessandrelli #define ECC_CURVE_NIST_P192_DIGITS 3
34a745d3acSDaniele Alessandrelli #define ECC_CURVE_NIST_P256_DIGITS 4
35a745d3acSDaniele Alessandrelli #define ECC_CURVE_NIST_P384_DIGITS 6
36e7fb0627SStefan Berger #define ECC_CURVE_NIST_P521_DIGITS 9
37e7fb0627SStefan Berger #define ECC_MAX_DIGITS DIV_ROUND_UP(521, 64) /* NIST P521 */
38a745d3acSDaniele Alessandrelli
39a745d3acSDaniele Alessandrelli #define ECC_DIGITS_TO_BYTES_SHIFT 3
40a745d3acSDaniele Alessandrelli
41a745d3acSDaniele Alessandrelli #define ECC_MAX_BYTES (ECC_MAX_DIGITS << ECC_DIGITS_TO_BYTES_SHIFT)
42a745d3acSDaniele Alessandrelli
43a745d3acSDaniele Alessandrelli #define ECC_POINT_INIT(x, y, ndigits) (struct ecc_point) { x, y, ndigits }
44a745d3acSDaniele Alessandrelli
45a745d3acSDaniele Alessandrelli /**
46a745d3acSDaniele Alessandrelli * ecc_swap_digits() - Copy ndigits from big endian array to native array
47a745d3acSDaniele Alessandrelli * @in: Input array
48a745d3acSDaniele Alessandrelli * @out: Output array
49a745d3acSDaniele Alessandrelli * @ndigits: Number of digits to copy
50a745d3acSDaniele Alessandrelli */
ecc_swap_digits(const void * in,u64 * out,unsigned int ndigits)51a745d3acSDaniele Alessandrelli static inline void ecc_swap_digits(const void *in, u64 *out, unsigned int ndigits)
52a745d3acSDaniele Alessandrelli {
53a745d3acSDaniele Alessandrelli const __be64 *src = (__force __be64 *)in;
54a745d3acSDaniele Alessandrelli int i;
55a745d3acSDaniele Alessandrelli
56a745d3acSDaniele Alessandrelli for (i = 0; i < ndigits; i++)
57a745d3acSDaniele Alessandrelli out[i] = get_unaligned_be64(&src[ndigits - 1 - i]);
58a745d3acSDaniele Alessandrelli }
59a745d3acSDaniele Alessandrelli
60a745d3acSDaniele Alessandrelli /**
61d67c96fbSStefan Berger * ecc_digits_from_bytes() - Create ndigits-sized digits array from byte array
62d67c96fbSStefan Berger * @in: Input byte array
63d67c96fbSStefan Berger * @nbytes Size of input byte array
64d67c96fbSStefan Berger * @out Output digits array
65d67c96fbSStefan Berger * @ndigits: Number of digits to create from byte array
66d67c96fbSStefan Berger */
67*c6ab5c91SStefan Berger void ecc_digits_from_bytes(const u8 *in, unsigned int nbytes,
68*c6ab5c91SStefan Berger u64 *out, unsigned int ndigits);
69d67c96fbSStefan Berger
70d67c96fbSStefan Berger /**
71a745d3acSDaniele Alessandrelli * ecc_is_key_valid() - Validate a given ECDH private key
72a745d3acSDaniele Alessandrelli *
73a745d3acSDaniele Alessandrelli * @curve_id: id representing the curve to use
74a745d3acSDaniele Alessandrelli * @ndigits: curve's number of digits
75a745d3acSDaniele Alessandrelli * @private_key: private key to be used for the given curve
76a745d3acSDaniele Alessandrelli * @private_key_len: private key length
77a745d3acSDaniele Alessandrelli *
78a745d3acSDaniele Alessandrelli * Returns 0 if the key is acceptable, a negative value otherwise
79a745d3acSDaniele Alessandrelli */
80a745d3acSDaniele Alessandrelli int ecc_is_key_valid(unsigned int curve_id, unsigned int ndigits,
81a745d3acSDaniele Alessandrelli const u64 *private_key, unsigned int private_key_len);
82a745d3acSDaniele Alessandrelli
83a745d3acSDaniele Alessandrelli /**
84a745d3acSDaniele Alessandrelli * ecc_gen_privkey() - Generates an ECC private key.
85a745d3acSDaniele Alessandrelli * The private key is a random integer in the range 0 < random < n, where n is a
86a745d3acSDaniele Alessandrelli * prime that is the order of the cyclic subgroup generated by the distinguished
87a745d3acSDaniele Alessandrelli * point G.
88a745d3acSDaniele Alessandrelli * @curve_id: id representing the curve to use
89a745d3acSDaniele Alessandrelli * @ndigits: curve number of digits
90a745d3acSDaniele Alessandrelli * @private_key: buffer for storing the generated private key
91a745d3acSDaniele Alessandrelli *
92a745d3acSDaniele Alessandrelli * Returns 0 if the private key was generated successfully, a negative value
93a745d3acSDaniele Alessandrelli * if an error occurred.
94a745d3acSDaniele Alessandrelli */
9501474b70SStefan Berger int ecc_gen_privkey(unsigned int curve_id, unsigned int ndigits,
9601474b70SStefan Berger u64 *private_key);
97a745d3acSDaniele Alessandrelli
98a745d3acSDaniele Alessandrelli /**
99a745d3acSDaniele Alessandrelli * ecc_make_pub_key() - Compute an ECC public key
100a745d3acSDaniele Alessandrelli *
101a745d3acSDaniele Alessandrelli * @curve_id: id representing the curve to use
102a745d3acSDaniele Alessandrelli * @ndigits: curve's number of digits
103a745d3acSDaniele Alessandrelli * @private_key: pregenerated private key for the given curve
104a745d3acSDaniele Alessandrelli * @public_key: buffer for storing the generated public key
105a745d3acSDaniele Alessandrelli *
106a745d3acSDaniele Alessandrelli * Returns 0 if the public key was generated successfully, a negative value
107a745d3acSDaniele Alessandrelli * if an error occurred.
108a745d3acSDaniele Alessandrelli */
109a745d3acSDaniele Alessandrelli int ecc_make_pub_key(const unsigned int curve_id, unsigned int ndigits,
110a745d3acSDaniele Alessandrelli const u64 *private_key, u64 *public_key);
111a745d3acSDaniele Alessandrelli
112a745d3acSDaniele Alessandrelli /**
113a745d3acSDaniele Alessandrelli * crypto_ecdh_shared_secret() - Compute a shared secret
114a745d3acSDaniele Alessandrelli *
115a745d3acSDaniele Alessandrelli * @curve_id: id representing the curve to use
116a745d3acSDaniele Alessandrelli * @ndigits: curve's number of digits
117a745d3acSDaniele Alessandrelli * @private_key: private key of part A
118a745d3acSDaniele Alessandrelli * @public_key: public key of counterpart B
119a745d3acSDaniele Alessandrelli * @secret: buffer for storing the calculated shared secret
120a745d3acSDaniele Alessandrelli *
121a745d3acSDaniele Alessandrelli * Note: It is recommended that you hash the result of crypto_ecdh_shared_secret
122a745d3acSDaniele Alessandrelli * before using it for symmetric encryption or HMAC.
123a745d3acSDaniele Alessandrelli *
124a745d3acSDaniele Alessandrelli * Returns 0 if the shared secret was generated successfully, a negative value
125a745d3acSDaniele Alessandrelli * if an error occurred.
126a745d3acSDaniele Alessandrelli */
127a745d3acSDaniele Alessandrelli int crypto_ecdh_shared_secret(unsigned int curve_id, unsigned int ndigits,
128a745d3acSDaniele Alessandrelli const u64 *private_key, const u64 *public_key,
129a745d3acSDaniele Alessandrelli u64 *secret);
130a745d3acSDaniele Alessandrelli
131a745d3acSDaniele Alessandrelli /**
132a745d3acSDaniele Alessandrelli * ecc_is_pubkey_valid_partial() - Partial public key validation
133a745d3acSDaniele Alessandrelli *
134a745d3acSDaniele Alessandrelli * @curve: elliptic curve domain parameters
135a745d3acSDaniele Alessandrelli * @pk: public key as a point
136a745d3acSDaniele Alessandrelli *
137a745d3acSDaniele Alessandrelli * Valdiate public key according to SP800-56A section 5.6.2.3.4 ECC Partial
138a745d3acSDaniele Alessandrelli * Public-Key Validation Routine.
139a745d3acSDaniele Alessandrelli *
140a745d3acSDaniele Alessandrelli * Note: There is no check that the public key is in the correct elliptic curve
141a745d3acSDaniele Alessandrelli * subgroup.
142a745d3acSDaniele Alessandrelli *
143a745d3acSDaniele Alessandrelli * Return: 0 if validation is successful, -EINVAL if validation is failed.
144a745d3acSDaniele Alessandrelli */
145a745d3acSDaniele Alessandrelli int ecc_is_pubkey_valid_partial(const struct ecc_curve *curve,
146a745d3acSDaniele Alessandrelli struct ecc_point *pk);
147a745d3acSDaniele Alessandrelli
148a745d3acSDaniele Alessandrelli /**
149a745d3acSDaniele Alessandrelli * ecc_is_pubkey_valid_full() - Full public key validation
150a745d3acSDaniele Alessandrelli *
151a745d3acSDaniele Alessandrelli * @curve: elliptic curve domain parameters
152a745d3acSDaniele Alessandrelli * @pk: public key as a point
153a745d3acSDaniele Alessandrelli *
154a745d3acSDaniele Alessandrelli * Valdiate public key according to SP800-56A section 5.6.2.3.3 ECC Full
155a745d3acSDaniele Alessandrelli * Public-Key Validation Routine.
156a745d3acSDaniele Alessandrelli *
157a745d3acSDaniele Alessandrelli * Return: 0 if validation is successful, -EINVAL if validation is failed.
158a745d3acSDaniele Alessandrelli */
159a745d3acSDaniele Alessandrelli int ecc_is_pubkey_valid_full(const struct ecc_curve *curve,
160a745d3acSDaniele Alessandrelli struct ecc_point *pk);
161a745d3acSDaniele Alessandrelli
162a745d3acSDaniele Alessandrelli /**
163a745d3acSDaniele Alessandrelli * vli_is_zero() - Determine is vli is zero
164a745d3acSDaniele Alessandrelli *
165a745d3acSDaniele Alessandrelli * @vli: vli to check.
166a745d3acSDaniele Alessandrelli * @ndigits: length of the @vli
167a745d3acSDaniele Alessandrelli */
168a745d3acSDaniele Alessandrelli bool vli_is_zero(const u64 *vli, unsigned int ndigits);
169a745d3acSDaniele Alessandrelli
170a745d3acSDaniele Alessandrelli /**
171a745d3acSDaniele Alessandrelli * vli_cmp() - compare left and right vlis
172a745d3acSDaniele Alessandrelli *
173a745d3acSDaniele Alessandrelli * @left: vli
174a745d3acSDaniele Alessandrelli * @right: vli
175a745d3acSDaniele Alessandrelli * @ndigits: length of both vlis
176a745d3acSDaniele Alessandrelli *
177a745d3acSDaniele Alessandrelli * Returns sign of @left - @right, i.e. -1 if @left < @right,
178a745d3acSDaniele Alessandrelli * 0 if @left == @right, 1 if @left > @right.
179a745d3acSDaniele Alessandrelli */
180a745d3acSDaniele Alessandrelli int vli_cmp(const u64 *left, const u64 *right, unsigned int ndigits);
181a745d3acSDaniele Alessandrelli
182a745d3acSDaniele Alessandrelli /**
183a745d3acSDaniele Alessandrelli * vli_sub() - Subtracts right from left
184a745d3acSDaniele Alessandrelli *
185a745d3acSDaniele Alessandrelli * @result: where to write result
186a745d3acSDaniele Alessandrelli * @left: vli
187a745d3acSDaniele Alessandrelli * @right vli
188a745d3acSDaniele Alessandrelli * @ndigits: length of all vlis
189a745d3acSDaniele Alessandrelli *
190a745d3acSDaniele Alessandrelli * Note: can modify in-place.
191a745d3acSDaniele Alessandrelli *
192a745d3acSDaniele Alessandrelli * Return: carry bit.
193a745d3acSDaniele Alessandrelli */
194a745d3acSDaniele Alessandrelli u64 vli_sub(u64 *result, const u64 *left, const u64 *right,
195a745d3acSDaniele Alessandrelli unsigned int ndigits);
196a745d3acSDaniele Alessandrelli
197a745d3acSDaniele Alessandrelli /**
198a745d3acSDaniele Alessandrelli * vli_from_be64() - Load vli from big-endian u64 array
199a745d3acSDaniele Alessandrelli *
200a745d3acSDaniele Alessandrelli * @dest: destination vli
201a745d3acSDaniele Alessandrelli * @src: source array of u64 BE values
202a745d3acSDaniele Alessandrelli * @ndigits: length of both vli and array
203a745d3acSDaniele Alessandrelli */
204a745d3acSDaniele Alessandrelli void vli_from_be64(u64 *dest, const void *src, unsigned int ndigits);
205a745d3acSDaniele Alessandrelli
206a745d3acSDaniele Alessandrelli /**
207a745d3acSDaniele Alessandrelli * vli_from_le64() - Load vli from little-endian u64 array
208a745d3acSDaniele Alessandrelli *
209a745d3acSDaniele Alessandrelli * @dest: destination vli
210a745d3acSDaniele Alessandrelli * @src: source array of u64 LE values
211a745d3acSDaniele Alessandrelli * @ndigits: length of both vli and array
212a745d3acSDaniele Alessandrelli */
213a745d3acSDaniele Alessandrelli void vli_from_le64(u64 *dest, const void *src, unsigned int ndigits);
214a745d3acSDaniele Alessandrelli
215a745d3acSDaniele Alessandrelli /**
216a745d3acSDaniele Alessandrelli * vli_mod_inv() - Modular inversion
217a745d3acSDaniele Alessandrelli *
218a745d3acSDaniele Alessandrelli * @result: where to write vli number
219a745d3acSDaniele Alessandrelli * @input: vli value to operate on
220a745d3acSDaniele Alessandrelli * @mod: modulus
221a745d3acSDaniele Alessandrelli * @ndigits: length of all vlis
222a745d3acSDaniele Alessandrelli */
223a745d3acSDaniele Alessandrelli void vli_mod_inv(u64 *result, const u64 *input, const u64 *mod,
224a745d3acSDaniele Alessandrelli unsigned int ndigits);
225a745d3acSDaniele Alessandrelli
226a745d3acSDaniele Alessandrelli /**
227a745d3acSDaniele Alessandrelli * vli_mod_mult_slow() - Modular multiplication
228a745d3acSDaniele Alessandrelli *
229a745d3acSDaniele Alessandrelli * @result: where to write result value
230a745d3acSDaniele Alessandrelli * @left: vli number to multiply with @right
231a745d3acSDaniele Alessandrelli * @right: vli number to multiply with @left
232a745d3acSDaniele Alessandrelli * @mod: modulus
233a745d3acSDaniele Alessandrelli * @ndigits: length of all vlis
234a745d3acSDaniele Alessandrelli *
235a745d3acSDaniele Alessandrelli * Note: Assumes that mod is big enough curve order.
236a745d3acSDaniele Alessandrelli */
237a745d3acSDaniele Alessandrelli void vli_mod_mult_slow(u64 *result, const u64 *left, const u64 *right,
238a745d3acSDaniele Alessandrelli const u64 *mod, unsigned int ndigits);
239a745d3acSDaniele Alessandrelli
240a745d3acSDaniele Alessandrelli /**
241eaffe377SDaniele Alessandrelli * vli_num_bits() - Counts the number of bits required for vli.
242eaffe377SDaniele Alessandrelli *
243eaffe377SDaniele Alessandrelli * @vli: vli to check.
244eaffe377SDaniele Alessandrelli * @ndigits: Length of the @vli
245eaffe377SDaniele Alessandrelli *
246eaffe377SDaniele Alessandrelli * Return: The number of bits required to represent @vli.
247eaffe377SDaniele Alessandrelli */
248eaffe377SDaniele Alessandrelli unsigned int vli_num_bits(const u64 *vli, unsigned int ndigits);
249eaffe377SDaniele Alessandrelli
250eaffe377SDaniele Alessandrelli /**
251eaffe377SDaniele Alessandrelli * ecc_aloc_point() - Allocate ECC point.
252eaffe377SDaniele Alessandrelli *
253eaffe377SDaniele Alessandrelli * @ndigits: Length of vlis in u64 qwords.
254eaffe377SDaniele Alessandrelli *
255eaffe377SDaniele Alessandrelli * Return: Pointer to the allocated point or NULL if allocation failed.
256eaffe377SDaniele Alessandrelli */
257eaffe377SDaniele Alessandrelli struct ecc_point *ecc_alloc_point(unsigned int ndigits);
258eaffe377SDaniele Alessandrelli
259eaffe377SDaniele Alessandrelli /**
260eaffe377SDaniele Alessandrelli * ecc_free_point() - Free ECC point.
261eaffe377SDaniele Alessandrelli *
262eaffe377SDaniele Alessandrelli * @p: The point to free.
263eaffe377SDaniele Alessandrelli */
264eaffe377SDaniele Alessandrelli void ecc_free_point(struct ecc_point *p);
265eaffe377SDaniele Alessandrelli
266eaffe377SDaniele Alessandrelli /**
267eaffe377SDaniele Alessandrelli * ecc_point_is_zero() - Check if point is zero.
268eaffe377SDaniele Alessandrelli *
269eaffe377SDaniele Alessandrelli * @p: Point to check for zero.
270eaffe377SDaniele Alessandrelli *
271eaffe377SDaniele Alessandrelli * Return: true if point is the point at infinity, false otherwise.
272eaffe377SDaniele Alessandrelli */
273eaffe377SDaniele Alessandrelli bool ecc_point_is_zero(const struct ecc_point *point);
274eaffe377SDaniele Alessandrelli
275eaffe377SDaniele Alessandrelli /**
276a745d3acSDaniele Alessandrelli * ecc_point_mult_shamir() - Add two points multiplied by scalars
277a745d3acSDaniele Alessandrelli *
278a745d3acSDaniele Alessandrelli * @result: resulting point
279a745d3acSDaniele Alessandrelli * @x: scalar to multiply with @p
280a745d3acSDaniele Alessandrelli * @p: point to multiply with @x
281a745d3acSDaniele Alessandrelli * @y: scalar to multiply with @q
282a745d3acSDaniele Alessandrelli * @q: point to multiply with @y
283a745d3acSDaniele Alessandrelli * @curve: curve
284a745d3acSDaniele Alessandrelli *
285a745d3acSDaniele Alessandrelli * Returns result = x * p + x * q over the curve.
286a745d3acSDaniele Alessandrelli * This works faster than two multiplications and addition.
287a745d3acSDaniele Alessandrelli */
288a745d3acSDaniele Alessandrelli void ecc_point_mult_shamir(const struct ecc_point *result,
289a745d3acSDaniele Alessandrelli const u64 *x, const struct ecc_point *p,
290a745d3acSDaniele Alessandrelli const u64 *y, const struct ecc_point *q,
291a745d3acSDaniele Alessandrelli const struct ecc_curve *curve);
292eaffe377SDaniele Alessandrelli
293a745d3acSDaniele Alessandrelli #endif
294