aboutsummaryrefslogtreecommitdiff
path: root/vendor/monocypher/monocypher.h
blob: cf635e88e4f5851e1f58a9e2b3e85b8029a73861 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
// Monocypher version __git__
//
// This file is dual-licensed.  Choose whichever licence you want from
// the two licences listed below.
//
// The first licence is a regular 2-clause BSD licence.  The second licence
// is the CC-0 from Creative Commons. It is intended to release Monocypher
// to the public domain.  The BSD licence serves as a fallback option.
//
// SPDX-License-Identifier: BSD-2-Clause OR CC0-1.0
//
// ------------------------------------------------------------------------
//
// Copyright (c) 2017-2019, Loup Vaillant
// All rights reserved.
//
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// 1. Redistributions of source code must retain the above copyright
//    notice, this list of conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright
//    notice, this list of conditions and the following disclaimer in the
//    documentation and/or other materials provided with the
//    distribution.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// ------------------------------------------------------------------------
//
// Written in 2017-2019 by Loup Vaillant
//
// To the extent possible under law, the author(s) have dedicated all copyright
// and related neighboring rights to this software to the public domain
// worldwide.  This software is distributed without any warranty.
//
// You should have received a copy of the CC0 Public Domain Dedication along
// with this software.  If not, see
// <https://creativecommons.org/publicdomain/zero/1.0/>

#ifndef MONOCYPHER_H
#define MONOCYPHER_H

#include <stddef.h>
#include <stdint.h>

#ifdef MONOCYPHER_CPP_NAMESPACE
namespace MONOCYPHER_CPP_NAMESPACE {
#elif defined(__cplusplus)
extern "C" {
#endif

// Constant time comparisons
// -------------------------

// Return 0 if a and b are equal, -1 otherwise
int crypto_verify16(const uint8_t a[16], const uint8_t b[16]);
int crypto_verify32(const uint8_t a[32], const uint8_t b[32]);
int crypto_verify64(const uint8_t a[64], const uint8_t b[64]);


// Erase sensitive data
// --------------------
void crypto_wipe(void *secret, size_t size);


// Authenticated encryption
// ------------------------
void crypto_aead_lock(uint8_t       *cipher_text,
                      uint8_t        mac  [16],
                      const uint8_t  key  [32],
                      const uint8_t  nonce[24],
                      const uint8_t *ad,         size_t ad_size,
                      const uint8_t *plain_text, size_t text_size);
int crypto_aead_unlock(uint8_t       *plain_text,
                       const uint8_t  mac  [16],
                       const uint8_t  key  [32],
                       const uint8_t  nonce[24],
                       const uint8_t *ad,          size_t ad_size,
                       const uint8_t *cipher_text, size_t text_size);

// Authenticated stream
// --------------------
typedef struct {
	uint64_t counter;
	uint8_t  key[32];
	uint8_t  nonce[8];
} crypto_aead_ctx;

void crypto_aead_init_x(crypto_aead_ctx *ctx,
                        const uint8_t key[32], const uint8_t nonce[24]);
void crypto_aead_init_djb(crypto_aead_ctx *ctx,
                          const uint8_t key[32], const uint8_t nonce[8]);
void crypto_aead_init_ietf(crypto_aead_ctx *ctx,
                           const uint8_t key[32], const uint8_t nonce[12]);

void crypto_aead_write(crypto_aead_ctx *ctx,
                       uint8_t         *cipher_text,
                       uint8_t          mac[16],
                       const uint8_t   *ad        , size_t ad_size,
                       const uint8_t   *plain_text, size_t text_size);
int crypto_aead_read(crypto_aead_ctx *ctx,
                     uint8_t         *plain_text,
                     const uint8_t    mac[16],
                     const uint8_t   *ad        , size_t ad_size,
                     const uint8_t   *cipher_text, size_t text_size);


// General purpose hash (BLAKE2b)
// ------------------------------

// Direct interface
void crypto_blake2b(uint8_t *hash,          size_t hash_size,
                    const uint8_t *message, size_t message_size);

void crypto_blake2b_keyed(uint8_t *hash,          size_t hash_size,
                          const uint8_t *key,     size_t key_size,
                          const uint8_t *message, size_t message_size);

// Incremental interface
typedef struct {
	// Do not rely on the size or contents of this type,
	// for they may change without notice.
	uint64_t hash[8];
	uint64_t input_offset[2];
	uint64_t input[16];
	size_t   input_idx;
	size_t   hash_size;
} crypto_blake2b_ctx;

void crypto_blake2b_init(crypto_blake2b_ctx *ctx, size_t hash_size);
void crypto_blake2b_keyed_init(crypto_blake2b_ctx *ctx, size_t hash_size,
                               const uint8_t *key, size_t key_size);
void crypto_blake2b_update(crypto_blake2b_ctx *ctx,
                           const uint8_t *message, size_t message_size);
void crypto_blake2b_final(crypto_blake2b_ctx *ctx, uint8_t *hash);


// Password key derivation (Argon2)
// --------------------------------
#define CRYPTO_ARGON2_D  0
#define CRYPTO_ARGON2_I  1
#define CRYPTO_ARGON2_ID 2

typedef struct {
	uint32_t algorithm;  // Argon2d, Argon2i, Argon2id
	uint32_t nb_blocks;  // memory hardness, >= 8 * nb_lanes
	uint32_t nb_passes;  // CPU hardness, >= 1 (>= 3 recommended for Argon2i)
	uint32_t nb_lanes;   // parallelism level (single threaded anyway)
} crypto_argon2_config;

typedef struct {
	const uint8_t *pass;
	const uint8_t *salt;
	uint32_t pass_size;
	uint32_t salt_size;  // 16 bytes recommended
} crypto_argon2_inputs;

typedef struct {
	const uint8_t *key; // may be NULL if no key
	const uint8_t *ad;  // may be NULL if no additional data
	uint32_t key_size;  // 0 if no key (32 bytes recommended otherwise)
	uint32_t ad_size;   // 0 if no additional data
} crypto_argon2_extras;

extern const crypto_argon2_extras crypto_argon2_no_extras;

void crypto_argon2(uint8_t *hash, uint32_t hash_size, void *work_area,
                   crypto_argon2_config config,
                   crypto_argon2_inputs inputs,
                   crypto_argon2_extras extras);


// Key exchange (X-25519)
// ----------------------

// Shared secrets are not quite random.
// Hash them to derive an actual shared key.
void crypto_x25519_public_key(uint8_t       public_key[32],
                              const uint8_t secret_key[32]);
void crypto_x25519(uint8_t       raw_shared_secret[32],
                   const uint8_t your_secret_key  [32],
                   const uint8_t their_public_key [32]);

// Conversion to EdDSA
void crypto_x25519_to_eddsa(uint8_t eddsa[32], const uint8_t x25519[32]);

// scalar "division"
// Used for OPRF.  Be aware that exponential blinding is less secure
// than Diffie-Hellman key exchange.
void crypto_x25519_inverse(uint8_t       blind_salt [32],
                           const uint8_t private_key[32],
                           const uint8_t curve_point[32]);

// "Dirty" versions of x25519_public_key().
// Use with crypto_elligator_rev().
// Leaks 3 bits of the private key.
void crypto_x25519_dirty_small(uint8_t pk[32], const uint8_t sk[32]);
void crypto_x25519_dirty_fast (uint8_t pk[32], const uint8_t sk[32]);


// Signatures
// ----------

// EdDSA with curve25519 + BLAKE2b
void crypto_eddsa_key_pair(uint8_t secret_key[64],
                           uint8_t public_key[32],
                           uint8_t seed[32]);
void crypto_eddsa_sign(uint8_t        signature [64],
                       const uint8_t  secret_key[64],
                       const uint8_t *message, size_t message_size);
int crypto_eddsa_check(const uint8_t  signature [64],
                       const uint8_t  public_key[32],
                       const uint8_t *message, size_t message_size);

// Conversion to X25519
void crypto_eddsa_to_x25519(uint8_t x25519[32], const uint8_t eddsa[32]);

// EdDSA building blocks
void crypto_eddsa_trim_scalar(uint8_t out[32], const uint8_t in[32]);
void crypto_eddsa_reduce(uint8_t reduced[32], const uint8_t expanded[64]);
void crypto_eddsa_mul_add(uint8_t r[32],
                          const uint8_t a[32],
                          const uint8_t b[32],
                          const uint8_t c[32]);
void crypto_eddsa_scalarbase(uint8_t point[32], const uint8_t scalar[32]);
int crypto_eddsa_check_equation(const uint8_t signature[64],
                                const uint8_t public_key[32],
                                const uint8_t h_ram[32]);


// Chacha20
// --------

// Specialised hash.
// Used to hash X25519 shared secrets.
void crypto_chacha20_h(uint8_t       out[32],
                       const uint8_t key[32],
                       const uint8_t in [16]);

// Unauthenticated stream cipher.
// Don't forget to add authentication.
uint64_t crypto_chacha20_djb(uint8_t       *cipher_text,
                             const uint8_t *plain_text,
                             size_t         text_size,
                             const uint8_t  key[32],
                             const uint8_t  nonce[8],
                             uint64_t       ctr);
uint32_t crypto_chacha20_ietf(uint8_t       *cipher_text,
                              const uint8_t *plain_text,
                              size_t         text_size,
                              const uint8_t  key[32],
                              const uint8_t  nonce[12],
                              uint32_t       ctr);
uint64_t crypto_chacha20_x(uint8_t       *cipher_text,
                           const uint8_t *plain_text,
                           size_t         text_size,
                           const uint8_t  key[32],
                           const uint8_t  nonce[24],
                           uint64_t       ctr);


// Poly 1305
// ---------

// This is a *one time* authenticator.
// Disclosing the mac reveals the key.
// See crypto_lock() on how to use it properly.

// Direct interface
void crypto_poly1305(uint8_t        mac[16],
                     const uint8_t *message, size_t message_size,
                     const uint8_t  key[32]);

// Incremental interface
typedef struct {
	// Do not rely on the size or contents of this type,
	// for they may change without notice.
	uint8_t  c[16];  // chunk of the message
	size_t   c_idx;  // How many bytes are there in the chunk.
	uint32_t r  [4]; // constant multiplier (from the secret key)
	uint32_t pad[4]; // random number added at the end (from the secret key)
	uint32_t h  [5]; // accumulated hash
} crypto_poly1305_ctx;

void crypto_poly1305_init  (crypto_poly1305_ctx *ctx, const uint8_t key[32]);
void crypto_poly1305_update(crypto_poly1305_ctx *ctx,
                            const uint8_t *message, size_t message_size);
void crypto_poly1305_final (crypto_poly1305_ctx *ctx, uint8_t mac[16]);


// Elligator 2
// -----------

// Elligator mappings proper
void crypto_elligator_map(uint8_t curve [32], const uint8_t hidden[32]);
int  crypto_elligator_rev(uint8_t hidden[32], const uint8_t curve [32],
                          uint8_t tweak);

// Easy to use key pair generation
void crypto_elligator_key_pair(uint8_t hidden[32], uint8_t secret_key[32],
                               uint8_t seed[32]);

#ifdef __cplusplus
}
#endif

#endif // MONOCYPHER_H