xref: /openbsd-src/lib/libcrypto/bn/s2n_bignum.h (revision 78843f4ef558416fa4bd7e0909fbe547e953d26d)
1 // Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
2 //
3 // Permission to use, copy, modify, and/or distribute this software for any
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5 // copyright notice and this permission notice appear in all copies.
6 //
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8 // WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
9 // MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
10 // ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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12 // ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
13 // OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
14 
15 // ----------------------------------------------------------------------------
16 // C prototypes for s2n-bignum functions, so you can use them in C programs via
17 //
18 //  #include "s2n-bignum.h"
19 //
20 // The functions are listed in alphabetical order with a brief description
21 // in comments for each one. For more detailed documentation see the comment
22 // banner at the top of the corresponding assembly (.S) file, and
23 // for the last word in what properties it satisfies see the spec in the
24 // formal proof (the .ml file in the architecture-specific directory).
25 //
26 // For some functions there are additional variants with names ending in
27 // "_alt". These have the same core mathematical functionality as their
28 // non-"alt" versions, but can be better suited to some microarchitectures:
29 //
30 //      - On x86, the "_alt" forms avoid BMI and ADX instruction set
31 //        extensions, so will run on any x86_64 machine, even older ones
32 //
33 //      - On ARM, the "_alt" forms target machines with higher multiplier
34 //        throughput, generally offering higher performance there.
35 // ----------------------------------------------------------------------------
36 
37 // Add, z := x + y
38 // Inputs x[m], y[n]; outputs function return (carry-out) and z[p]
39 extern uint64_t bignum_add (uint64_t p, uint64_t *z, uint64_t m, uint64_t *x, uint64_t n, uint64_t *y);
40 
41 // Add modulo p_25519, z := (x + y) mod p_25519, assuming x and y reduced
42 // Inputs x[4], y[4]; output z[4]
43 extern void bignum_add_p25519 (uint64_t z[static 4], uint64_t x[static 4], uint64_t y[static 4]);
44 
45 // Add modulo p_256, z := (x + y) mod p_256, assuming x and y reduced
46 // Inputs x[4], y[4]; output z[4]
47 extern void bignum_add_p256 (uint64_t z[static 4], uint64_t x[static 4], uint64_t y[static 4]);
48 
49 // Add modulo p_256k1, z := (x + y) mod p_256k1, assuming x and y reduced
50 // Inputs x[4], y[4]; output z[4]
51 extern void bignum_add_p256k1 (uint64_t z[static 4], uint64_t x[static 4], uint64_t y[static 4]);
52 
53 // Add modulo p_384, z := (x + y) mod p_384, assuming x and y reduced
54 // Inputs x[6], y[6]; output z[6]
55 extern void bignum_add_p384 (uint64_t z[static 6], uint64_t x[static 6], uint64_t y[static 6]);
56 
57 // Add modulo p_521, z := (x + y) mod p_521, assuming x and y reduced
58 // Inputs x[9], y[9]; output z[9]
59 extern void bignum_add_p521 (uint64_t z[static 9], uint64_t x[static 9], uint64_t y[static 9]);
60 
61 // Compute "amontification" constant z :== 2^{128k} (congruent mod m)
62 // Input m[k]; output z[k]; temporary buffer t[>=k]
63 extern void bignum_amontifier (uint64_t k, uint64_t *z, uint64_t *m, uint64_t *t);
64 
65 // Almost-Montgomery multiply, z :== (x * y / 2^{64k}) (congruent mod m)
66 // Inputs x[k], y[k], m[k]; output z[k]
67 extern void bignum_amontmul (uint64_t k, uint64_t *z, uint64_t *x, uint64_t *y, uint64_t *m);
68 
69 // Almost-Montgomery reduce, z :== (x' / 2^{64p}) (congruent mod m)
70 // Inputs x[n], m[k], p; output z[k]
71 extern void bignum_amontredc (uint64_t k, uint64_t *z, uint64_t n, uint64_t *x, uint64_t *m, uint64_t p);
72 
73 // Almost-Montgomery square, z :== (x^2 / 2^{64k}) (congruent mod m)
74 // Inputs x[k], m[k]; output z[k]
75 extern void bignum_amontsqr (uint64_t k, uint64_t *z, uint64_t *x, uint64_t *m);
76 
77 // Convert 4-digit (256-bit) bignum to/from big-endian form
78 // Input x[4]; output z[4]
79 extern void bignum_bigendian_4 (uint64_t z[static 4], uint64_t x[static 4]);
80 
81 // Convert 6-digit (384-bit) bignum to/from big-endian form
82 // Input x[6]; output z[6]
83 extern void bignum_bigendian_6 (uint64_t z[static 6], uint64_t x[static 6]);
84 
85 // Select bitfield starting at bit n with length l <= 64
86 // Inputs x[k], n, l; output function return
87 extern uint64_t bignum_bitfield (uint64_t k, uint64_t *x, uint64_t n, uint64_t l);
88 
89 // Return size of bignum in bits
90 // Input x[k]; output function return
91 extern uint64_t bignum_bitsize (uint64_t k, uint64_t *x);
92 
93 // Divide by a single (nonzero) word, z := x / m and return x mod m
94 // Inputs x[n], m; outputs function return (remainder) and z[k]
95 extern uint64_t bignum_cdiv (uint64_t k, uint64_t *z, uint64_t n, uint64_t *x, uint64_t m);
96 
97 // Divide by a single word, z := x / m when known to be exact
98 // Inputs x[n], m; output z[k]
99 extern void bignum_cdiv_exact (uint64_t k, uint64_t *z, uint64_t n, uint64_t *x, uint64_t m);
100 
101 // Count leading zero digits (64-bit words)
102 // Input x[k]; output function return
103 extern uint64_t bignum_cld (uint64_t k, uint64_t *x);
104 
105 // Count leading zero bits
106 // Input x[k]; output function return
107 extern uint64_t bignum_clz (uint64_t k, uint64_t *x);
108 
109 // Multiply-add with single-word multiplier, z := z + c * y
110 // Inputs c, y[n]; outputs function return (carry-out) and z[k]
111 extern uint64_t bignum_cmadd (uint64_t k, uint64_t *z, uint64_t c, uint64_t n, uint64_t *y);
112 
113 // Negated multiply-add with single-word multiplier, z := z - c * y
114 // Inputs c, y[n]; outputs function return (negative carry-out) and z[k]
115 extern uint64_t bignum_cmnegadd (uint64_t k, uint64_t *z, uint64_t c, uint64_t n, uint64_t *y);
116 
117 // Find modulus of bignum w.r.t. single nonzero word m, returning x mod m
118 // Input x[k], m; output function return
119 extern uint64_t bignum_cmod (uint64_t k, uint64_t *x, uint64_t m);
120 
121 // Multiply by a single word, z := c * y
122 // Inputs c, y[n]; outputs function return (carry-out) and z[k]
123 extern uint64_t bignum_cmul (uint64_t k, uint64_t *z, uint64_t c, uint64_t n, uint64_t *y);
124 
125 // Multiply by a single word modulo p_25519, z := (c * x) mod p_25519, assuming x reduced
126 // Inputs c, x[4]; output z[4]
127 extern void bignum_cmul_p25519 (uint64_t z[static 4], uint64_t c, uint64_t x[static 4]);
128 extern void bignum_cmul_p25519_alt (uint64_t z[static 4], uint64_t c, uint64_t x[static 4]);
129 
130 // Multiply by a single word modulo p_256, z := (c * x) mod p_256, assuming x reduced
131 // Inputs c, x[4]; output z[4]
132 extern void bignum_cmul_p256 (uint64_t z[static 4], uint64_t c, uint64_t x[static 4]);
133 extern void bignum_cmul_p256_alt (uint64_t z[static 4], uint64_t c, uint64_t x[static 4]);
134 
135 // Multiply by a single word modulo p_256k1, z := (c * x) mod p_256k1, assuming x reduced
136 // Inputs c, x[4]; output z[4]
137 extern void bignum_cmul_p256k1 (uint64_t z[static 4], uint64_t c, uint64_t x[static 4]);
138 extern void bignum_cmul_p256k1_alt (uint64_t z[static 4], uint64_t c, uint64_t x[static 4]);
139 
140 // Multiply by a single word modulo p_384, z := (c * x) mod p_384, assuming x reduced
141 // Inputs c, x[6]; output z[6]
142 extern void bignum_cmul_p384 (uint64_t z[static 6], uint64_t c, uint64_t x[static 6]);
143 extern void bignum_cmul_p384_alt (uint64_t z[static 6], uint64_t c, uint64_t x[static 6]);
144 
145 // Multiply by a single word modulo p_521, z := (c * x) mod p_521, assuming x reduced
146 // Inputs c, x[9]; output z[9]
147 extern void bignum_cmul_p521 (uint64_t z[static 9], uint64_t c, uint64_t x[static 9]);
148 extern void bignum_cmul_p521_alt (uint64_t z[static 9], uint64_t c, uint64_t x[static 9]);
149 
150 // Test bignums for coprimality, gcd(x,y) = 1
151 // Inputs x[m], y[n]; output function return; temporary buffer t[>=2*max(m,n)]
152 extern uint64_t bignum_coprime (uint64_t m, uint64_t *x, uint64_t n, uint64_t *y, uint64_t *t);
153 
154 // Copy bignum with zero-extension or truncation, z := x
155 // Input x[n]; output z[k]
156 extern void bignum_copy (uint64_t k, uint64_t *z, uint64_t n, uint64_t *x);
157 
158 // Count trailing zero digits (64-bit words)
159 // Input x[k]; output function return
160 extern uint64_t bignum_ctd (uint64_t k, uint64_t *x);
161 
162 // Count trailing zero bits
163 // Input x[k]; output function return
164 extern uint64_t bignum_ctz (uint64_t k, uint64_t *x);
165 
166 // Convert from almost-Montgomery form, z := (x / 2^256) mod p_256
167 // Input x[4]; output z[4]
168 extern void bignum_deamont_p256 (uint64_t z[static 4], uint64_t x[static 4]);
169 extern void bignum_deamont_p256_alt (uint64_t z[static 4], uint64_t x[static 4]);
170 
171 // Convert from almost-Montgomery form, z := (x / 2^256) mod p_256k1
172 // Input x[4]; output z[4]
173 extern void bignum_deamont_p256k1 (uint64_t z[static 4], uint64_t x[static 4]);
174 
175 // Convert from almost-Montgomery form, z := (x / 2^384) mod p_384
176 // Input x[6]; output z[6]
177 extern void bignum_deamont_p384 (uint64_t z[static 6], uint64_t x[static 6]);
178 extern void bignum_deamont_p384_alt (uint64_t z[static 6], uint64_t x[static 6]);
179 
180 // Convert from almost-Montgomery form z := (x / 2^576) mod p_521
181 // Input x[9]; output z[9]
182 extern void bignum_deamont_p521 (uint64_t z[static 9], uint64_t x[static 9]);
183 
184 // Convert from (almost-)Montgomery form z := (x / 2^{64k}) mod m
185 // Inputs x[k], m[k]; output z[k]
186 extern void bignum_demont (uint64_t k, uint64_t *z, uint64_t *x, uint64_t *m);
187 
188 // Convert from Montgomery form z := (x / 2^256) mod p_256, assuming x reduced
189 // Input x[4]; output z[4]
190 extern void bignum_demont_p256 (uint64_t z[static 4], uint64_t x[static 4]);
191 extern void bignum_demont_p256_alt (uint64_t z[static 4], uint64_t x[static 4]);
192 
193 // Convert from Montgomery form z := (x / 2^256) mod p_256k1, assuming x reduced
194 // Input x[4]; output z[4]
195 extern void bignum_demont_p256k1 (uint64_t z[static 4], uint64_t x[static 4]);
196 
197 // Convert from Montgomery form z := (x / 2^384) mod p_384, assuming x reduced
198 // Input x[6]; output z[6]
199 extern void bignum_demont_p384 (uint64_t z[static 6], uint64_t x[static 6]);
200 extern void bignum_demont_p384_alt (uint64_t z[static 6], uint64_t x[static 6]);
201 
202 // Convert from Montgomery form z := (x / 2^576) mod p_521, assuming x reduced
203 // Input x[9]; output z[9]
204 extern void bignum_demont_p521 (uint64_t z[static 9], uint64_t x[static 9]);
205 
206 // Select digit x[n]
207 // Inputs x[k], n; output function return
208 extern uint64_t bignum_digit (uint64_t k, uint64_t *x, uint64_t n);
209 
210 // Return size of bignum in digits (64-bit word)
211 // Input x[k]; output function return
212 extern uint64_t bignum_digitsize (uint64_t k, uint64_t *x);
213 
214 // Divide bignum by 10: z' := z div 10, returning remainder z mod 10
215 // Inputs z[k]; outputs function return (remainder) and z[k]
216 extern uint64_t bignum_divmod10 (uint64_t k, uint64_t *z);
217 
218 // Double modulo p_25519, z := (2 * x) mod p_25519, assuming x reduced
219 // Input x[4]; output z[4]
220 extern void bignum_double_p25519 (uint64_t z[static 4], uint64_t x[static 4]);
221 
222 // Double modulo p_256, z := (2 * x) mod p_256, assuming x reduced
223 // Input x[4]; output z[4]
224 extern void bignum_double_p256 (uint64_t z[static 4], uint64_t x[static 4]);
225 
226 // Double modulo p_256k1, z := (2 * x) mod p_256k1, assuming x reduced
227 // Input x[4]; output z[4]
228 extern void bignum_double_p256k1 (uint64_t z[static 4], uint64_t x[static 4]);
229 
230 // Double modulo p_384, z := (2 * x) mod p_384, assuming x reduced
231 // Input x[6]; output z[6]
232 extern void bignum_double_p384 (uint64_t z[static 6], uint64_t x[static 6]);
233 
234 // Double modulo p_521, z := (2 * x) mod p_521, assuming x reduced
235 // Input x[9]; output z[9]
236 extern void bignum_double_p521 (uint64_t z[static 9], uint64_t x[static 9]);
237 
238 // Extended Montgomery reduce, returning results in input-output buffer
239 // Inputs z[2*k], m[k], w; outputs function return (extra result bit) and z[2*k]
240 extern uint64_t bignum_emontredc (uint64_t k, uint64_t *z, uint64_t *m, uint64_t w);
241 
242 // Extended Montgomery reduce in 8-digit blocks, results in input-output buffer
243 // Inputs z[2*k], m[k], w; outputs function return (extra result bit) and z[2*k]
244 extern uint64_t bignum_emontredc_8n (uint64_t k, uint64_t *z, uint64_t *m, uint64_t w);
245 
246 // Test bignums for equality, x = y
247 // Inputs x[m], y[n]; output function return
248 extern uint64_t bignum_eq (uint64_t m, uint64_t *x, uint64_t n, uint64_t *y);
249 
250 // Test bignum for even-ness
251 // Input x[k]; output function return
252 extern uint64_t bignum_even (uint64_t k, uint64_t *x);
253 
254 // Convert 4-digit (256-bit) bignum from big-endian bytes
255 // Input x[32] (bytes); output z[4]
256 extern void bignum_frombebytes_4 (uint64_t z[static 4], uint8_t x[static 32]);
257 
258 // Convert 6-digit (384-bit) bignum from big-endian bytes
259 // Input x[48] (bytes); output z[6]
260 extern void bignum_frombebytes_6 (uint64_t z[static 6], uint8_t x[static 48]);
261 
262 // Convert 4-digit (256-bit) bignum from little-endian bytes
263 // Input x[32] (bytes); output z[4]
264 extern void bignum_fromlebytes_4 (uint64_t z[static 4], uint8_t x[static 32]);
265 
266 // Convert 6-digit (384-bit) bignum from little-endian bytes
267 // Input x[48] (bytes); output z[6]
268 extern void bignum_fromlebytes_6 (uint64_t z[static 6], uint8_t x[static 48]);
269 
270 // Convert little-endian bytes to 9-digit 528-bit bignum
271 // Input x[66] (bytes); output z[9]
272 extern void bignum_fromlebytes_p521 (uint64_t z[static 9],uint8_t x[static 66]);
273 
274 // Compare bignums, x >= y
275 // Inputs x[m], y[n]; output function return
276 extern uint64_t bignum_ge (uint64_t m, uint64_t *x, uint64_t n, uint64_t *y);
277 
278 // Compare bignums, x > y
279 // Inputs x[m], y[n]; output function return
280 extern uint64_t bignum_gt (uint64_t m, uint64_t *x, uint64_t n, uint64_t *y);
281 
282 // Halve modulo p_256, z := (x / 2) mod p_256, assuming x reduced
283 // Input x[4]; output z[4]
284 extern void bignum_half_p256 (uint64_t z[static 4], uint64_t x[static 4]);
285 
286 // Halve modulo p_256k1, z := (x / 2) mod p_256k1, assuming x reduced
287 // Input x[4]; output z[4]
288 extern void bignum_half_p256k1 (uint64_t z[static 4], uint64_t x[static 4]);
289 
290 // Halve modulo p_384, z := (x / 2) mod p_384, assuming x reduced
291 // Input x[6]; output z[6]
292 extern void bignum_half_p384 (uint64_t z[static 6], uint64_t x[static 6]);
293 
294 // Halve modulo p_521, z := (x / 2) mod p_521, assuming x reduced
295 // Input x[9]; output z[9]
296 extern void bignum_half_p521 (uint64_t z[static 9], uint64_t x[static 9]);
297 
298 // Test bignum for zero-ness, x = 0
299 // Input x[k]; output function return
300 extern uint64_t bignum_iszero (uint64_t k, uint64_t *x);
301 
302 // Multiply z := x * y
303 // Inputs x[16], y[16]; output z[32]; temporary buffer t[>=32]
304 extern void bignum_kmul_16_32 (uint64_t z[static 32], uint64_t x[static 16], uint64_t y[static 16], uint64_t t[static 32]);
305 
306 // Multiply z := x * y
307 // Inputs x[32], y[32]; output z[64]; temporary buffer t[>=96]
308 extern void bignum_kmul_32_64 (uint64_t z[static 64], uint64_t x[static 32], uint64_t y[static 32], uint64_t t[static 96]);
309 
310 // Square, z := x^2
311 // Input x[16]; output z[32]; temporary buffer t[>=24]
312 extern void bignum_ksqr_16_32 (uint64_t z[static 32], uint64_t x[static 16], uint64_t t[static 24]);
313 
314 // Square, z := x^2
315 // Input x[32]; output z[64]; temporary buffer t[>=72]
316 extern void bignum_ksqr_32_64 (uint64_t z[static 64], uint64_t x[static 32], uint64_t t[static 72]);
317 
318 // Compare bignums, x <= y
319 // Inputs x[m], y[n]; output function return
320 extern uint64_t bignum_le (uint64_t m, uint64_t *x, uint64_t n, uint64_t *y);
321 
322 // Convert 4-digit (256-bit) bignum to/from little-endian form
323 // Input x[4]; output z[4]
324 extern void bignum_littleendian_4 (uint64_t z[static 4], uint64_t x[static 4]);
325 
326 // Convert 6-digit (384-bit) bignum to/from little-endian form
327 // Input x[6]; output z[6]
328 extern void bignum_littleendian_6 (uint64_t z[static 6], uint64_t x[static 6]);
329 
330 // Compare bignums, x < y
331 // Inputs x[m], y[n]; output function return
332 extern uint64_t bignum_lt (uint64_t m, uint64_t *x, uint64_t n, uint64_t *y);
333 
334 // Multiply-add, z := z + x * y
335 // Inputs x[m], y[n]; outputs function return (carry-out) and z[k]
336 extern uint64_t bignum_madd (uint64_t k, uint64_t *z, uint64_t m, uint64_t *x, uint64_t n, uint64_t *y);
337 
338 // Reduce modulo group order, z := x mod n_256
339 // Input x[k]; output z[4]
340 extern void bignum_mod_n256 (uint64_t z[static 4], uint64_t k, uint64_t *x);
341 extern void bignum_mod_n256_alt (uint64_t z[static 4], uint64_t k, uint64_t *x);
342 
343 // Reduce modulo group order, z := x mod n_256
344 // Input x[4]; output z[4]
345 extern void bignum_mod_n256_4 (uint64_t z[static 4], uint64_t x[static 4]);
346 
347 // Reduce modulo group order, z := x mod n_256k1
348 // Input x[4]; output z[4]
349 extern void bignum_mod_n256k1_4 (uint64_t z[static 4], uint64_t x[static 4]);
350 
351 // Reduce modulo group order, z := x mod n_384
352 // Input x[k]; output z[6]
353 extern void bignum_mod_n384 (uint64_t z[static 6], uint64_t k, uint64_t *x);
354 extern void bignum_mod_n384_alt (uint64_t z[static 6], uint64_t k, uint64_t *x);
355 
356 // Reduce modulo group order, z := x mod n_384
357 // Input x[6]; output z[6]
358 extern void bignum_mod_n384_6 (uint64_t z[static 6], uint64_t x[static 6]);
359 
360 // Reduce modulo group order, z := x mod n_521
361 // Input x[9]; output z[9]
362 extern void bignum_mod_n521_9 (uint64_t z[static 9], uint64_t x[static 9]);
363 extern void bignum_mod_n521_9_alt (uint64_t z[static 9], uint64_t x[static 9]);
364 
365 // Reduce modulo field characteristic, z := x mod p_25519
366 // Input x[4]; output z[4]
367 extern void bignum_mod_p25519_4 (uint64_t z[static 4], uint64_t x[static 4]);
368 
369 // Reduce modulo field characteristic, z := x mod p_256
370 // Input x[k]; output z[4]
371 extern void bignum_mod_p256 (uint64_t z[static 4], uint64_t k, uint64_t *x);
372 extern void bignum_mod_p256_alt (uint64_t z[static 4], uint64_t k, uint64_t *x);
373 
374 // Reduce modulo field characteristic, z := x mod p_256
375 // Input x[4]; output z[4]
376 extern void bignum_mod_p256_4 (uint64_t z[static 4], uint64_t x[static 4]);
377 
378 // Reduce modulo field characteristic, z := x mod p_256k1
379 // Input x[4]; output z[4]
380 extern void bignum_mod_p256k1_4 (uint64_t z[static 4], uint64_t x[static 4]);
381 
382 // Reduce modulo field characteristic, z := x mod p_384
383 // Input x[k]; output z[6]
384 extern void bignum_mod_p384 (uint64_t z[static 6], uint64_t k, uint64_t *x);
385 extern void bignum_mod_p384_alt (uint64_t z[static 6], uint64_t k, uint64_t *x);
386 
387 // Reduce modulo field characteristic, z := x mod p_384
388 // Input x[6]; output z[6]
389 extern void bignum_mod_p384_6 (uint64_t z[static 6], uint64_t x[static 6]);
390 
391 // Reduce modulo field characteristic, z := x mod p_521
392 // Input x[9]; output z[9]
393 extern void bignum_mod_p521_9 (uint64_t z[static 9], uint64_t x[static 9]);
394 
395 // Add modulo m, z := (x + y) mod m, assuming x and y reduced
396 // Inputs x[k], y[k], m[k]; output z[k]
397 extern void bignum_modadd (uint64_t k, uint64_t *z, uint64_t *x, uint64_t *y, uint64_t *m);
398 
399 // Double modulo m, z := (2 * x) mod m, assuming x reduced
400 // Inputs x[k], m[k]; output z[k]
401 extern void bignum_moddouble (uint64_t k, uint64_t *z, uint64_t *x, uint64_t *m);
402 
403 // Compute "modification" constant z := 2^{64k} mod m
404 // Input m[k]; output z[k]; temporary buffer t[>=k]
405 extern void bignum_modifier (uint64_t k, uint64_t *z, uint64_t *m, uint64_t *t);
406 
407 // Invert modulo m, z = (1/a) mod b, assuming b is an odd number > 1, a coprime to b
408 // Inputs a[k], b[k]; output z[k]; temporary buffer t[>=3*k]
409 extern void bignum_modinv (uint64_t k, uint64_t *z, uint64_t *a, uint64_t *b, uint64_t *t);
410 
411 // Optionally negate modulo m, z := (-x) mod m (if p nonzero) or z := x (if p zero), assuming x reduced
412 // Inputs p, x[k], m[k]; output z[k]
413 extern void bignum_modoptneg (uint64_t k, uint64_t *z, uint64_t p, uint64_t *x, uint64_t *m);
414 
415 // Subtract modulo m, z := (x - y) mod m, assuming x and y reduced
416 // Inputs x[k], y[k], m[k]; output z[k]
417 extern void bignum_modsub (uint64_t k, uint64_t *z, uint64_t *x, uint64_t *y, uint64_t *m);
418 
419 // Compute "montification" constant z := 2^{128k} mod m
420 // Input m[k]; output z[k]; temporary buffer t[>=k]
421 extern void bignum_montifier (uint64_t k, uint64_t *z, uint64_t *m, uint64_t *t);
422 
423 // Montgomery multiply, z := (x * y / 2^{64k}) mod m
424 // Inputs x[k], y[k], m[k]; output z[k]
425 extern void bignum_montmul (uint64_t k, uint64_t *z, uint64_t *x, uint64_t *y, uint64_t *m);
426 
427 // Montgomery multiply, z := (x * y / 2^256) mod p_256
428 // Inputs x[4], y[4]; output z[4]
429 extern void bignum_montmul_p256 (uint64_t z[static 4], uint64_t x[static 4], uint64_t y[static 4]);
430 extern void bignum_montmul_p256_alt (uint64_t z[static 4], uint64_t x[static 4], uint64_t y[static 4]);
431 
432 // Montgomery multiply, z := (x * y / 2^256) mod p_256k1
433 // Inputs x[4], y[4]; output z[4]
434 extern void bignum_montmul_p256k1 (uint64_t z[static 4], uint64_t x[static 4], uint64_t y[static 4]);
435 extern void bignum_montmul_p256k1_alt (uint64_t z[static 4], uint64_t x[static 4], uint64_t y[static 4]);
436 
437 // Montgomery multiply, z := (x * y / 2^384) mod p_384
438 // Inputs x[6], y[6]; output z[6]
439 extern void bignum_montmul_p384 (uint64_t z[static 6], uint64_t x[static 6], uint64_t y[static 6]);
440 extern void bignum_montmul_p384_alt (uint64_t z[static 6], uint64_t x[static 6], uint64_t y[static 6]);
441 
442 // Montgomery multiply, z := (x * y / 2^576) mod p_521
443 // Inputs x[9], y[9]; output z[9]
444 extern void bignum_montmul_p521 (uint64_t z[static 9], uint64_t x[static 9], uint64_t y[static 9]);
445 extern void bignum_montmul_p521_alt (uint64_t z[static 9], uint64_t x[static 9], uint64_t y[static 9]);
446 
447 // Montgomery reduce, z := (x' / 2^{64p}) MOD m
448 // Inputs x[n], m[k], p; output z[k]
449 extern void bignum_montredc (uint64_t k, uint64_t *z, uint64_t n, uint64_t *x, uint64_t *m, uint64_t p);
450 
451 // Montgomery square, z := (x^2 / 2^{64k}) mod m
452 // Inputs x[k], m[k]; output z[k]
453 extern void bignum_montsqr (uint64_t k, uint64_t *z, uint64_t *x, uint64_t *m);
454 
455 // Montgomery square, z := (x^2 / 2^256) mod p_256
456 // Input x[4]; output z[4]
457 extern void bignum_montsqr_p256 (uint64_t z[static 4], uint64_t x[static 4]);
458 extern void bignum_montsqr_p256_alt (uint64_t z[static 4], uint64_t x[static 4]);
459 
460 // Montgomery square, z := (x^2 / 2^256) mod p_256k1
461 // Input x[4]; output z[4]
462 extern void bignum_montsqr_p256k1 (uint64_t z[static 4], uint64_t x[static 4]);
463 extern void bignum_montsqr_p256k1_alt (uint64_t z[static 4], uint64_t x[static 4]);
464 
465 // Montgomery square, z := (x^2 / 2^384) mod p_384
466 // Input x[6]; output z[6]
467 extern void bignum_montsqr_p384 (uint64_t z[static 6], uint64_t x[static 6]);
468 extern void bignum_montsqr_p384_alt (uint64_t z[static 6], uint64_t x[static 6]);
469 
470 // Montgomery square, z := (x^2 / 2^576) mod p_521
471 // Input x[9]; output z[9]
472 extern void bignum_montsqr_p521 (uint64_t z[static 9], uint64_t x[static 9]);
473 extern void bignum_montsqr_p521_alt (uint64_t z[static 9], uint64_t x[static 9]);
474 
475 // Multiply z := x * y
476 // Inputs x[m], y[n]; output z[k]
477 extern void bignum_mul (uint64_t k, uint64_t *z, uint64_t m, uint64_t *x, uint64_t n, uint64_t *y);
478 
479 // Multiply z := x * y
480 // Inputs x[4], y[4]; output z[8]
481 extern void bignum_mul_4_8 (uint64_t z[static 8], uint64_t x[static 4], uint64_t y[static 4]);
482 extern void bignum_mul_4_8_alt (uint64_t z[static 8], uint64_t x[static 4], uint64_t y[static 4]);
483 
484 // Multiply z := x * y
485 // Inputs x[6], y[6]; output z[12]
486 extern void bignum_mul_6_12 (uint64_t z[static 12], uint64_t x[static 6], uint64_t y[static 6]);
487 extern void bignum_mul_6_12_alt (uint64_t z[static 12], uint64_t x[static 6], uint64_t y[static 6]);
488 
489 // Multiply z := x * y
490 // Inputs x[8], y[8]; output z[16]
491 extern void bignum_mul_8_16 (uint64_t z[static 16], uint64_t x[static 8], uint64_t y[static 8]);
492 extern void bignum_mul_8_16_alt (uint64_t z[static 16], uint64_t x[static 8], uint64_t y[static 8]);
493 
494 // Multiply modulo p_25519, z := (x * y) mod p_25519
495 // Inputs x[4], y[4]; output z[4]
496 extern void bignum_mul_p25519 (uint64_t z[static 4], uint64_t x[static 4], uint64_t y[static 4]);
497 extern void bignum_mul_p25519_alt (uint64_t z[static 4], uint64_t x[static 4], uint64_t y[static 4]);
498 
499 // Multiply modulo p_256k1, z := (x * y) mod p_256k1
500 // Inputs x[4], y[4]; output z[4]
501 extern void bignum_mul_p256k1 (uint64_t z[static 4], uint64_t x[static 4], uint64_t y[static 4]);
502 extern void bignum_mul_p256k1_alt (uint64_t z[static 4], uint64_t x[static 4], uint64_t y[static 4]);
503 
504 // Multiply modulo p_521, z := (x * y) mod p_521, assuming x and y reduced
505 // Inputs x[9], y[9]; output z[9]
506 extern void bignum_mul_p521 (uint64_t z[static 9], uint64_t x[static 9], uint64_t y[static 9]);
507 extern void bignum_mul_p521_alt (uint64_t z[static 9], uint64_t x[static 9], uint64_t y[static 9]);
508 
509 // Multiply bignum by 10 and add word: z := 10 * z + d
510 // Inputs z[k], d; outputs function return (carry) and z[k]
511 extern uint64_t bignum_muladd10 (uint64_t k, uint64_t *z, uint64_t d);
512 
513 // Multiplex/select z := x (if p nonzero) or z := y (if p zero)
514 // Inputs p, x[k], y[k]; output z[k]
515 extern void bignum_mux (uint64_t p, uint64_t k, uint64_t *z, uint64_t *x, uint64_t *y);
516 
517 // 256-bit multiplex/select z := x (if p nonzero) or z := y (if p zero)
518 // Inputs p, x[4], y[4]; output z[4]
519 extern void bignum_mux_4 (uint64_t p, uint64_t z[static 4],uint64_t x[static 4], uint64_t y[static 4]);
520 
521 // 384-bit multiplex/select z := x (if p nonzero) or z := y (if p zero)
522 // Inputs p, x[6], y[6]; output z[6]
523 extern void bignum_mux_6 (uint64_t p, uint64_t z[static 6],uint64_t x[static 6], uint64_t y[static 6]);
524 
525 // Select element from 16-element table, z := xs[k*i]
526 // Inputs xs[16*k], i; output z[k]
527 extern void bignum_mux16 (uint64_t k, uint64_t *z, uint64_t *xs, uint64_t i);
528 
529 // Negate modulo p_25519, z := (-x) mod p_25519, assuming x reduced
530 // Input x[4]; output z[4]
531 extern void bignum_neg_p25519 (uint64_t z[static 4], uint64_t x[static 4]);
532 
533 // Negate modulo p_256, z := (-x) mod p_256, assuming x reduced
534 // Input x[4]; output z[4]
535 extern void bignum_neg_p256 (uint64_t z[static 4], uint64_t x[static 4]);
536 
537 // Negate modulo p_256k1, z := (-x) mod p_256k1, assuming x reduced
538 // Input x[4]; output z[4]
539 extern void bignum_neg_p256k1 (uint64_t z[static 4], uint64_t x[static 4]);
540 
541 // Negate modulo p_384, z := (-x) mod p_384, assuming x reduced
542 // Input x[6]; output z[6]
543 extern void bignum_neg_p384 (uint64_t z[static 6], uint64_t x[static 6]);
544 
545 // Negate modulo p_521, z := (-x) mod p_521, assuming x reduced
546 // Input x[9]; output z[9]
547 extern void bignum_neg_p521 (uint64_t z[static 9], uint64_t x[static 9]);
548 
549 // Negated modular inverse, z := (-1/x) mod 2^{64k}
550 // Input x[k]; output z[k]
551 extern void bignum_negmodinv (uint64_t k, uint64_t *z, uint64_t *x);
552 
553 // Test bignum for nonzero-ness x =/= 0
554 // Input x[k]; output function return
555 extern uint64_t bignum_nonzero (uint64_t k, uint64_t *x);
556 
557 // Test 256-bit bignum for nonzero-ness x =/= 0
558 // Input x[4]; output function return
559 extern uint64_t bignum_nonzero_4(uint64_t x[static 4]);
560 
561 // Test 384-bit bignum for nonzero-ness x =/= 0
562 // Input x[6]; output function return
563 extern uint64_t bignum_nonzero_6(uint64_t x[static 6]);
564 
565 // Normalize bignum in-place by shifting left till top bit is 1
566 // Input z[k]; outputs function return (bits shifted left) and z[k]
567 extern uint64_t bignum_normalize (uint64_t k, uint64_t *z);
568 
569 // Test bignum for odd-ness
570 // Input x[k]; output function return
571 extern uint64_t bignum_odd (uint64_t k, uint64_t *x);
572 
573 // Convert single digit to bignum, z := n
574 // Input n; output z[k]
575 extern void bignum_of_word (uint64_t k, uint64_t *z, uint64_t n);
576 
577 // Optionally add, z := x + y (if p nonzero) or z := x (if p zero)
578 // Inputs x[k], p, y[k]; outputs function return (carry-out) and z[k]
579 extern uint64_t bignum_optadd (uint64_t k, uint64_t *z, uint64_t *x, uint64_t p, uint64_t *y);
580 
581 // Optionally negate, z := -x (if p nonzero) or z := x (if p zero)
582 // Inputs p, x[k]; outputs function return (nonzero input) and z[k]
583 extern uint64_t bignum_optneg (uint64_t k, uint64_t *z, uint64_t p, uint64_t *x);
584 
585 // Optionally negate modulo p_25519, z := (-x) mod p_25519 (if p nonzero) or z := x (if p zero), assuming x reduced
586 // Inputs p, x[4]; output z[4]
587 extern void bignum_optneg_p25519 (uint64_t z[static 4], uint64_t p, uint64_t x[static 4]);
588 
589 // Optionally negate modulo p_256, z := (-x) mod p_256 (if p nonzero) or z := x (if p zero), assuming x reduced
590 // Inputs p, x[4]; output z[4]
591 extern void bignum_optneg_p256 (uint64_t z[static 4], uint64_t p, uint64_t x[static 4]);
592 
593 // Optionally negate modulo p_256k1, z := (-x) mod p_256k1 (if p nonzero) or z := x (if p zero), assuming x reduced
594 // Inputs p, x[4]; output z[4]
595 extern void bignum_optneg_p256k1 (uint64_t z[static 4], uint64_t p, uint64_t x[static 4]);
596 
597 // Optionally negate modulo p_384, z := (-x) mod p_384 (if p nonzero) or z := x (if p zero), assuming x reduced
598 // Inputs p, x[6]; output z[6]
599 extern void bignum_optneg_p384 (uint64_t z[static 6], uint64_t p, uint64_t x[static 6]);
600 
601 // Optionally negate modulo p_521, z := (-x) mod p_521 (if p nonzero) or z := x (if p zero), assuming x reduced
602 // Inputs p, x[9]; output z[9]
603 extern void bignum_optneg_p521 (uint64_t z[static 9], uint64_t p, uint64_t x[static 9]);
604 
605 // Optionally subtract, z := x - y (if p nonzero) or z := x (if p zero)
606 // Inputs x[k], p, y[k]; outputs function return (carry-out) and z[k]
607 extern uint64_t bignum_optsub (uint64_t k, uint64_t *z, uint64_t *x, uint64_t p, uint64_t *y);
608 
609 // Optionally subtract or add, z := x + sgn(p) * y interpreting p as signed
610 // Inputs x[k], p, y[k]; outputs function return (carry-out) and z[k]
611 extern uint64_t bignum_optsubadd (uint64_t k, uint64_t *z, uint64_t *x, uint64_t p, uint64_t *y);
612 
613 // Return bignum of power of 2, z := 2^n
614 // Input n; output z[k]
615 extern void bignum_pow2 (uint64_t k, uint64_t *z, uint64_t n);
616 
617 // Shift bignum left by c < 64 bits z := x * 2^c
618 // Inputs x[n], c; outputs function return (carry-out) and z[k]
619 extern uint64_t bignum_shl_small (uint64_t k, uint64_t *z, uint64_t n, uint64_t *x, uint64_t c);
620 
621 // Shift bignum right by c < 64 bits z := floor(x / 2^c)
622 // Inputs x[n], c; outputs function return (bits shifted out) and z[k]
623 extern uint64_t bignum_shr_small (uint64_t k, uint64_t *z, uint64_t n, uint64_t *x, uint64_t c);
624 
625 // Square, z := x^2
626 // Input x[n]; output z[k]
627 extern void bignum_sqr (uint64_t k, uint64_t *z, uint64_t n, uint64_t *x);
628 
629 // Square, z := x^2
630 // Input x[4]; output z[8]
631 extern void bignum_sqr_4_8 (uint64_t z[static 8], uint64_t x[static 4]);
632 extern void bignum_sqr_4_8_alt (uint64_t z[static 8], uint64_t x[static 4]);
633 
634 // Square, z := x^2
635 // Input x[6]; output z[12]
636 extern void bignum_sqr_6_12 (uint64_t z[static 12], uint64_t x[static 6]);
637 extern void bignum_sqr_6_12_alt (uint64_t z[static 12], uint64_t x[static 6]);
638 
639 // Square, z := x^2
640 // Input x[8]; output z[16]
641 extern void bignum_sqr_8_16 (uint64_t z[static 16], uint64_t x[static 8]);
642 extern void bignum_sqr_8_16_alt (uint64_t z[static 16], uint64_t x[static 8]);
643 
644 // Square modulo p_25519, z := (x^2) mod p_25519
645 // Input x[4]; output z[4]
646 extern void bignum_sqr_p25519 (uint64_t z[static 4], uint64_t x[static 4]);
647 extern void bignum_sqr_p25519_alt (uint64_t z[static 4], uint64_t x[static 4]);
648 
649 // Square modulo p_256k1, z := (x^2) mod p_256k1
650 // Input x[4]; output z[4]
651 extern void bignum_sqr_p256k1 (uint64_t z[static 4], uint64_t x[static 4]);
652 extern void bignum_sqr_p256k1_alt (uint64_t z[static 4], uint64_t x[static 4]);
653 
654 // Square modulo p_521, z := (x^2) mod p_521, assuming x reduced
655 // Input x[9]; output z[9]
656 extern void bignum_sqr_p521 (uint64_t z[static 9], uint64_t x[static 9]);
657 extern void bignum_sqr_p521_alt (uint64_t z[static 9], uint64_t x[static 9]);
658 
659 // Subtract, z := x - y
660 // Inputs x[m], y[n]; outputs function return (carry-out) and z[p]
661 extern uint64_t bignum_sub (uint64_t p, uint64_t *z, uint64_t m, uint64_t *x, uint64_t n, uint64_t *y);
662 
663 // Subtract modulo p_25519, z := (x - y) mod p_25519, assuming x and y reduced
664 // Inputs x[4], y[4]; output z[4]
665 extern void bignum_sub_p25519 (uint64_t z[static 4], uint64_t x[static 4], uint64_t y[static 4]);
666 
667 // Subtract modulo p_256, z := (x - y) mod p_256, assuming x and y reduced
668 // Inputs x[4], y[4]; output z[4]
669 extern void bignum_sub_p256 (uint64_t z[static 4], uint64_t x[static 4], uint64_t y[static 4]);
670 
671 // Subtract modulo p_256k1, z := (x - y) mod p_256k1, assuming x and y reduced
672 // Inputs x[4], y[4]; output z[4]
673 extern void bignum_sub_p256k1 (uint64_t z[static 4], uint64_t x[static 4], uint64_t y[static 4]);
674 
675 // Subtract modulo p_384, z := (x - y) mod p_384, assuming x and y reduced
676 // Inputs x[6], y[6]; output z[6]
677 extern void bignum_sub_p384 (uint64_t z[static 6], uint64_t x[static 6], uint64_t y[static 6]);
678 
679 // Subtract modulo p_521, z := (x - y) mod p_521, assuming x and y reduced
680 // Inputs x[9], y[9]; output z[9]
681 extern void bignum_sub_p521 (uint64_t z[static 9], uint64_t x[static 9], uint64_t y[static 9]);
682 
683 // Convert 4-digit (256-bit) bignum to big-endian bytes
684 // Input x[4]; output z[32] (bytes)
685 extern void bignum_tobebytes_4 (uint8_t z[static 32], uint64_t x[static 4]);
686 
687 // Convert 6-digit (384-bit) bignum to big-endian bytes
688 // Input x[6]; output z[48] (bytes)
689 extern void bignum_tobebytes_6 (uint8_t z[static 48], uint64_t x[static 6]);
690 
691 // Convert 4-digit (256-bit) bignum to little-endian bytes
692 // Input x[4]; output z[32] (bytes)
693 extern void bignum_tolebytes_4 (uint8_t z[static 32], uint64_t x[static 4]);
694 
695 // Convert 6-digit (384-bit) bignum to little-endian bytes
696 // Input x[6]; output z[48] (bytes)
697 extern void bignum_tolebytes_6 (uint8_t z[static 48], uint64_t x[static 6]);
698 
699 // Convert 9-digit 528-bit bignum to little-endian bytes
700 // Input x[6]; output z[66] (bytes)
701 extern void bignum_tolebytes_p521 (uint8_t z[static 66], uint64_t x[static 9]);
702 
703 // Convert to Montgomery form z := (2^256 * x) mod p_256
704 // Input x[4]; output z[4]
705 extern void bignum_tomont_p256 (uint64_t z[static 4], uint64_t x[static 4]);
706 extern void bignum_tomont_p256_alt (uint64_t z[static 4], uint64_t x[static 4]);
707 
708 // Convert to Montgomery form z := (2^256 * x) mod p_256k1
709 // Input x[4]; output z[4]
710 extern void bignum_tomont_p256k1 (uint64_t z[static 4], uint64_t x[static 4]);
711 extern void bignum_tomont_p256k1_alt (uint64_t z[static 4], uint64_t x[static 4]);
712 
713 // Convert to Montgomery form z := (2^384 * x) mod p_384
714 // Input x[6]; output z[6]
715 extern void bignum_tomont_p384 (uint64_t z[static 6], uint64_t x[static 6]);
716 extern void bignum_tomont_p384_alt (uint64_t z[static 6], uint64_t x[static 6]);
717 
718 // Convert to Montgomery form z := (2^576 * x) mod p_521
719 // Input x[9]; output z[9]
720 extern void bignum_tomont_p521 (uint64_t z[static 9], uint64_t x[static 9]);
721 
722 // Triple modulo p_256, z := (3 * x) mod p_256
723 // Input x[4]; output z[4]
724 extern void bignum_triple_p256 (uint64_t z[static 4], uint64_t x[static 4]);
725 extern void bignum_triple_p256_alt (uint64_t z[static 4], uint64_t x[static 4]);
726 
727 // Triple modulo p_256k1, z := (3 * x) mod p_256k1
728 // Input x[4]; output z[4]
729 extern void bignum_triple_p256k1 (uint64_t z[static 4], uint64_t x[static 4]);
730 extern void bignum_triple_p256k1_alt (uint64_t z[static 4], uint64_t x[static 4]);
731 
732 // Triple modulo p_384, z := (3 * x) mod p_384
733 // Input x[6]; output z[6]
734 extern void bignum_triple_p384 (uint64_t z[static 6], uint64_t x[static 6]);
735 extern void bignum_triple_p384_alt (uint64_t z[static 6], uint64_t x[static 6]);
736 
737 // Triple modulo p_521, z := (3 * x) mod p_521, assuming x reduced
738 // Input x[9]; output z[9]
739 extern void bignum_triple_p521 (uint64_t z[static 9], uint64_t x[static 9]);
740 extern void bignum_triple_p521_alt (uint64_t z[static 9], uint64_t x[static 9]);
741 
742 // Montgomery ladder step for curve25519
743 // Inputs point[8], pp[16], b; output rr[16]
744 extern void curve25519_ladderstep(uint64_t rr[16],uint64_t point[8],uint64_t pp[16],uint64_t b);
745 extern void curve25519_ladderstep_alt(uint64_t rr[16],uint64_t point[8],uint64_t pp[16],uint64_t b);
746 
747 // Projective scalar multiplication, x coordinate only, for curve25519
748 // Inputs scalar[4], point[4]; output res[8]
749 extern void curve25519_pxscalarmul(uint64_t res[static 8],uint64_t scalar[static 4],uint64_t point[static 4]);
750 extern void curve25519_pxscalarmul_alt(uint64_t res[static 8],uint64_t scalar[static 4],uint64_t point[static 4]);
751 
752 // x25519 function for curve25519
753 // Inputs scalar[4], point[4]; output res[4]
754 extern void curve25519_x25519(uint64_t res[static 4],uint64_t scalar[static 4],uint64_t point[static 4]);
755 extern void curve25519_x25519_alt(uint64_t res[static 4],uint64_t scalar[static 4],uint64_t point[static 4]);
756 
757 // x25519 function for curve25519 on base element 9
758 // Input scalar[4]; output res[4]
759 extern void curve25519_x25519base(uint64_t res[static 4],uint64_t scalar[static 4]);
760 extern void curve25519_x25519base_alt(uint64_t res[static 4],uint64_t scalar[static 4]);
761 
762 // Extended projective addition for edwards25519
763 // Inputs p1[16], p2[16]; output p3[16]
764 extern void edwards25519_epadd(uint64_t p3[static 16],uint64_t p1[static 16],uint64_t p2[static 16]);
765 extern void edwards25519_epadd_alt(uint64_t p3[static 16],uint64_t p1[static 16],uint64_t p2[static 16]);
766 
767 // Extended projective doubling for edwards25519
768 // Inputs p1[12]; output p3[16]
769 extern void edwards25519_epdouble(uint64_t p3[static 16],uint64_t p1[static 12]);
770 extern void edwards25519_epdouble_alt(uint64_t p3[static 16],uint64_t p1[static 12]);
771 
772 // Projective doubling for edwards25519
773 // Inputs p1[12]; output p3[12]
774 extern void edwards25519_pdouble(uint64_t p3[static 12],uint64_t p1[static 12]);
775 extern void edwards25519_pdouble_alt(uint64_t p3[static 12],uint64_t p1[static 12]);
776 
777 // Extended projective + precomputed mixed addition for edwards25519
778 // Inputs p1[16], p2[12]; output p3[16]
779 extern void edwards25519_pepadd(uint64_t p3[static 16],uint64_t p1[static 16],uint64_t p2[static 12]);
780 extern void edwards25519_pepadd_alt(uint64_t p3[static 16],uint64_t p1[static 16],uint64_t p2[static 12]);
781 
782 // Point addition on NIST curve P-256 in Montgomery-Jacobian coordinates
783 // Inputs p1[12], p2[12]; output p3[12]
784 extern void p256_montjadd(uint64_t p3[static 12],uint64_t p1[static 12],uint64_t p2[static 12]);
785 
786 // Point doubling on NIST curve P-256 in Montgomery-Jacobian coordinates
787 // Inputs p1[12]; output p3[12]
788 extern void p256_montjdouble(uint64_t p3[static 12],uint64_t p1[static 12]);
789 
790 // Point mixed addition on NIST curve P-256 in Montgomery-Jacobian coordinates
791 // Inputs p1[12], p2[8]; output p3[12]
792 extern void p256_montjmixadd(uint64_t p3[static 12],uint64_t p1[static 12],uint64_t p2[static 8]);
793 
794 // Point addition on NIST curve P-384 in Montgomery-Jacobian coordinates
795 // Inputs p1[18], p2[18]; output p3[18]
796 extern void p384_montjadd(uint64_t p3[static 18],uint64_t p1[static 18],uint64_t p2[static 18]);
797 
798 // Point doubling on NIST curve P-384 in Montgomery-Jacobian coordinates
799 // Inputs p1[18]; output p3[18]
800 extern void p384_montjdouble(uint64_t p3[static 18],uint64_t p1[static 18]);
801 
802 // Point mixed addition on NIST curve P-384 in Montgomery-Jacobian coordinates
803 // Inputs p1[18], p2[12]; output p3[18]
804 extern void p384_montjmixadd(uint64_t p3[static 18],uint64_t p1[static 18],uint64_t p2[static 12]);
805 
806 // Point addition on NIST curve P-521 in Jacobian coordinates
807 // Inputs p1[27], p2[27]; output p3[27]
808 extern void p521_jadd(uint64_t p3[static 27],uint64_t p1[static 27],uint64_t p2[static 27]);
809 
810 // Point doubling on NIST curve P-521 in Jacobian coordinates
811 // Input p1[27]; output p3[27]
812 extern void p521_jdouble(uint64_t p3[static 27],uint64_t p1[static 27]);
813 
814 // Point mixed addition on NIST curve P-521 in Jacobian coordinates
815 // Inputs p1[27], p2[18]; output p3[27]
816 extern void p521_jmixadd(uint64_t p3[static 27],uint64_t p1[static 27],uint64_t p2[static 18]);
817 
818 // Point addition on SECG curve secp256k1 in Jacobian coordinates
819 // Inputs p1[12], p2[12]; output p3[12]
820 extern void secp256k1_jadd(uint64_t p3[static 12],uint64_t p1[static 12],uint64_t p2[static 12]);
821 
822 // Point doubling on SECG curve secp256k1 in Jacobian coordinates
823 // Input p1[12]; output p3[12]
824 extern void secp256k1_jdouble(uint64_t p3[static 12],uint64_t p1[static 12]);
825 
826 // Point mixed addition on SECG curve secp256k1 in Jacobian coordinates
827 // Inputs p1[12], p2[8]; output p3[12]
828 extern void secp256k1_jmixadd(uint64_t p3[static 12],uint64_t p1[static 12],uint64_t p2[static 8]);
829 
830 // Reverse the bytes in a single word
831 // Input a; output function return
832 extern uint64_t word_bytereverse (uint64_t a);
833 
834 // Count leading zero bits in a single word
835 // Input a; output function return
836 extern uint64_t word_clz (uint64_t a);
837 
838 // Count trailing zero bits in a single word
839 // Input a; output function return
840 extern uint64_t word_ctz (uint64_t a);
841 
842 // Return maximum of two unsigned 64-bit words
843 // Inputs a, b; output function return
844 extern uint64_t word_max (uint64_t a, uint64_t b);
845 
846 // Return minimum of two unsigned 64-bit words
847 // Inputs a, b; output function return
848 extern uint64_t word_min (uint64_t a, uint64_t b);
849 
850 // Single-word negated modular inverse (-1/a) mod 2^64
851 // Input a; output function return
852 extern uint64_t word_negmodinv (uint64_t a);
853 
854 // Single-word reciprocal, 2^64 + ret = ceil(2^128/a) - 1 if MSB of "a" is set
855 // Input a; output function return
856 extern uint64_t word_recip (uint64_t a);
857