| 1 | /* -*-c-*- |
| 2 | * |
| 3 | * The SHA3 algorithm family |
| 4 | * |
| 5 | * (c) 2017 Straylight/Edgeware |
| 6 | */ |
| 7 | |
| 8 | /*----- Licensing notice --------------------------------------------------* |
| 9 | * |
| 10 | * This file is part of Catacomb. |
| 11 | * |
| 12 | * Catacomb is free software; you can redistribute it and/or modify |
| 13 | * it under the terms of the GNU Library General Public License as |
| 14 | * published by the Free Software Foundation; either version 2 of the |
| 15 | * License, or (at your option) any later version. |
| 16 | * |
| 17 | * Catacomb is distributed in the hope that it will be useful, |
| 18 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 19 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 20 | * GNU Library General Public License for more details. |
| 21 | * |
| 22 | * You should have received a copy of the GNU Library General Public |
| 23 | * License along with Catacomb; if not, write to the Free |
| 24 | * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, |
| 25 | * MA 02111-1307, USA. |
| 26 | */ |
| 27 | |
| 28 | #ifndef CATACOMB_SHA3_H |
| 29 | #define CATACOMB_SHA3_H |
| 30 | |
| 31 | #ifdef __cplusplus |
| 32 | extern "C" { |
| 33 | #endif |
| 34 | |
| 35 | /*----- Notes on the SHA3 algorithm family --------------------------------* |
| 36 | * |
| 37 | * The winner of the SHA3 competition was Keccak, designed by Guido Bertoni, |
| 38 | * Joan Daemen, Michaƫl Peeters, and Gilles Van Assche. The algorithm uses |
| 39 | * their `sponge construction', based on a fixed attempt to instantiate an |
| 40 | * `ideal permutation'. The construction is rather versatile, and NIST has |
| 41 | * standardized a number of algorithms based on it. |
| 42 | * |
| 43 | * The basic offerings are the drop-in replacements for the SHA2 family. |
| 44 | * These are slower than is ideal, because of the decision to provide O(2^n) |
| 45 | * resistance to second-preimage attacks for the n-bit hash function, which |
| 46 | * means that, effectively, the capacity parameter is set unnecessarily |
| 47 | * large. (There was a major fuss when NIST tried to change this in a draft |
| 48 | * of te standard.) All of the obvious hash modes, e.g., HMAC, MGF, can be |
| 49 | * applied to the SHA3 hash functions, though I can't really recommend this: |
| 50 | * there's almost certainly a better way of doing whatever it is. |
| 51 | * |
| 52 | * Other members of the family are: SHAKE and cSHAKE, `extendable-output |
| 53 | * funnctions' which can be used directly in place of MGFs; and KMAC, a |
| 54 | * message authentication code with arbitrary-length key, message, and tag, |
| 55 | * which can therefore be used as a key-derivation function. The cSHAKE |
| 56 | * construction, on which KMAC is based, introduces a personalization string |
| 57 | * which can be used for domain separation. |
| 58 | */ |
| 59 | |
| 60 | /*----- Header files ------------------------------------------------------*/ |
| 61 | |
| 62 | #include <mLib/bits.h> |
| 63 | |
| 64 | #ifndef CATACOMB_KECCAK1600_H |
| 65 | # include "keccak1600.h" |
| 66 | #endif |
| 67 | |
| 68 | #ifndef CATACOMB_GCIPHER_H |
| 69 | # include "gcipher.h" |
| 70 | #endif |
| 71 | |
| 72 | #ifndef CATACOMB_GHASH_H |
| 73 | # include "ghash.h" |
| 74 | #endif |
| 75 | |
| 76 | #ifndef CATACOMB_GMAC_H |
| 77 | # include "gmac.h" |
| 78 | #endif |
| 79 | |
| 80 | #ifndef CATACOMB_GRAND_H |
| 81 | # include "grand.h" |
| 82 | #endif |
| 83 | |
| 84 | /*----- The SHA3 hash function family -------------------------------------*/ |
| 85 | |
| 86 | typedef struct sha3_ctx { |
| 87 | keccak1600_state s; |
| 88 | unsigned r, w, n; |
| 89 | octet buf[200]; |
| 90 | } sha3_ctx; |
| 91 | #define sha3_224_ctx sha3_ctx |
| 92 | #define sha3_256_ctx sha3_ctx |
| 93 | #define sha3_384_ctx sha3_ctx |
| 94 | #define sha3_512_ctx sha3_ctx |
| 95 | |
| 96 | #define SHA3_224_HASHSZ 28 |
| 97 | #define SHA3_256_HASHSZ 32 |
| 98 | #define SHA3_384_HASHSZ 48 |
| 99 | #define SHA3_512_HASHSZ 64 |
| 100 | |
| 101 | #define SHA3_224_BUFSZ 144 |
| 102 | #define SHA3_256_BUFSZ 136 |
| 103 | #define SHA3_384_BUFSZ 104 |
| 104 | #define SHA3_512_BUFSZ 72 |
| 105 | |
| 106 | #define SHA3_STATESZ (sizeof(sha3_ctx)) |
| 107 | #define SHA3_224_STATESZ SHA3_STATESZ |
| 108 | #define SHA3_256_STATESZ SHA3_STATESZ |
| 109 | #define SHA3_384_STATESZ SHA3_STATESZ |
| 110 | #define SHA3_512_STATESZ SHA3_STATESZ |
| 111 | |
| 112 | /* --- @sha3_{224,256,384,512}_init@ --- * |
| 113 | * |
| 114 | * Arguments: @sha3_ctx *ctx@ = pointer to context block to initialize |
| 115 | * |
| 116 | * Returns: --- |
| 117 | * |
| 118 | * Use: Initializes a SHA3 hashing context for use. |
| 119 | */ |
| 120 | |
| 121 | extern void sha3_224_init(sha3_ctx */*ctx*/); |
| 122 | extern void sha3_256_init(sha3_ctx */*ctx*/); |
| 123 | extern void sha3_384_init(sha3_ctx */*ctx*/); |
| 124 | extern void sha3_512_init(sha3_ctx */*ctx*/); |
| 125 | |
| 126 | /* --- @sha3_hash@ --- * |
| 127 | * |
| 128 | * Arguments: @sha3_ctx *ctx@ = pointer to context bock |
| 129 | * @const void *p@ = pointer to data to hash |
| 130 | * @size_t sz@ = size of buffer to hash |
| 131 | * |
| 132 | * Returns: --- |
| 133 | * |
| 134 | * Use: Hashes a buffer of data. The buffer may be of any size and |
| 135 | * alignment. |
| 136 | */ |
| 137 | |
| 138 | #define sha3_224_hash sha3_hash |
| 139 | #define sha3_256_hash sha3_hash |
| 140 | #define sha3_384_hash sha3_hash |
| 141 | #define sha3_512_hash sha3_hash |
| 142 | |
| 143 | extern void sha3_hash(sha3_ctx */*ctx*/, const void */*p*/, size_t /*sz*/); |
| 144 | |
| 145 | /* --- @sha3_done@ --- * |
| 146 | * |
| 147 | * Arguments: @sha3_ctx *ctx@ = pointer to context block |
| 148 | * @void *hash@ = pointer to output buffer |
| 149 | * |
| 150 | * Returns: --- |
| 151 | * |
| 152 | * Use: Returns the hash of the data read so far. |
| 153 | */ |
| 154 | |
| 155 | #define sha3_224_done sha3_done |
| 156 | #define sha3_256_done sha3_done |
| 157 | #define sha3_384_done sha3_done |
| 158 | #define sha3_512_done sha3_done |
| 159 | |
| 160 | extern void sha3_done(sha3_ctx */*ctx*/, void */*hash*/); |
| 161 | |
| 162 | /* --- @sha3_{224,256,384,512}_set@ --- * |
| 163 | * |
| 164 | * Arguments: @sha3_ctx *ctx@ = pointer to context block |
| 165 | * @const void *buf@ = pointer to state buffer |
| 166 | * @unsigned long count@ = current count of bytes processed |
| 167 | * |
| 168 | * Returns: --- |
| 169 | * |
| 170 | * Use: Initializes a context block from a given state. This is |
| 171 | * something of a kludge for the benefit of HMAC, but there are |
| 172 | * better ways to use SHA3 as a MAC. |
| 173 | * |
| 174 | * Furthermore, the @count@ argument is expected to be zero or |
| 175 | * be the output of @sha3_state@ below. Doing anything else |
| 176 | * won't work properly. |
| 177 | */ |
| 178 | |
| 179 | extern void sha3_224_set(sha3_ctx */*ctx*/, |
| 180 | const void */*buf*/, unsigned long /*count*/); |
| 181 | extern void sha3_256_set(sha3_ctx */*ctx*/, |
| 182 | const void */*buf*/, unsigned long /*count*/); |
| 183 | extern void sha3_384_set(sha3_ctx */*ctx*/, |
| 184 | const void */*buf*/, unsigned long /*count*/); |
| 185 | extern void sha3_512_set(sha3_ctx */*ctx*/, |
| 186 | const void */*buf*/, unsigned long /*count*/); |
| 187 | |
| 188 | /* --- @sha3_state@ --- * |
| 189 | * |
| 190 | * Arguments: @sha3_ctx *ctx@ = pointer to context block |
| 191 | * @void *state@ = pointer to buffer for current state |
| 192 | * |
| 193 | * Returns: A value which is meaningful to @sha3_..._set@. |
| 194 | * |
| 195 | * Use: Returns the current state of the hash function such that it |
| 196 | * can be passed to @sha3_..._set@. |
| 197 | */ |
| 198 | |
| 199 | #define sha3_224_state sha3_state |
| 200 | #define sha3_256_state sha3_state |
| 201 | #define sha3_384_state sha3_state |
| 202 | #define sha3_512_state sha3_state |
| 203 | |
| 204 | extern unsigned long sha3_state(sha3_ctx */*ctx*/, void */*state*/); |
| 205 | |
| 206 | /* --- Generic hash interface --- */ |
| 207 | |
| 208 | extern const gchash sha3_224, sha3_256, sha3_384, sha3_512; |
| 209 | |
| 210 | /*----- The cSHAKE XOF algorithm ------------------------------------------*/ |
| 211 | |
| 212 | typedef struct shake_ctx { |
| 213 | sha3_ctx h; |
| 214 | unsigned st, op; |
| 215 | } shake_ctx; |
| 216 | #define shake128_ctx shake_ctx |
| 217 | #define shake256_ctx shake_ctx |
| 218 | |
| 219 | #define SHAKE128_KEYSZ 16 |
| 220 | #define SHAKE256_KEYSZ 32 |
| 221 | |
| 222 | #define SHAKE128_HASHSZ 32 /* Somewhat arbitrary... */ |
| 223 | #define SHAKE256_HASHSZ 64 |
| 224 | |
| 225 | extern const octet shake128_keysz[], shake256_keysz[]; |
| 226 | |
| 227 | /* --- @cshake{128,256}_init@ --- * |
| 228 | * |
| 229 | * Arguments: @shake_ctx *ctx@ = pointer to context to initialize |
| 230 | * @const void *func@ = NIST-allocated function name |
| 231 | * @size_t fsz@ = length of function name |
| 232 | * @const void *perso@ = user personalization string |
| 233 | * @size_t psz@ = length of personalization string |
| 234 | * |
| 235 | * Returns: --- |
| 236 | * |
| 237 | * Use: Initializes a cSHAKE context. The context is initially in |
| 238 | * the `absorbing' state: feed it data with @shake_hash@. |
| 239 | */ |
| 240 | |
| 241 | extern void cshake128_init(shake_ctx */*ctx*/, |
| 242 | const void */*func*/, size_t /*fsz*/, |
| 243 | const void */*perso*/, size_t /*psz*/); |
| 244 | |
| 245 | extern void cshake256_init(shake_ctx */*ctx*/, |
| 246 | const void */*func*/, size_t /*fsz*/, |
| 247 | const void */*perso*/, size_t /*psz*/); |
| 248 | |
| 249 | /* --- @shake{128,256}_init@ --- * |
| 250 | * |
| 251 | * Arguments: @sha3_ctx *ctx@ = pointer to context to initialize |
| 252 | * |
| 253 | * Returns: --- |
| 254 | * |
| 255 | * Use: Initializes a SHAKE context. The context is initially in |
| 256 | * the `absorbing' state: feed it data with @shake_hash@. |
| 257 | */ |
| 258 | |
| 259 | extern void shake128_init(shake_ctx */*ctx*/); |
| 260 | extern void shake256_init(shake_ctx */*ctx*/); |
| 261 | |
| 262 | /* --- @shake_hash@ --- * |
| 263 | * |
| 264 | * Arguments: @shake_ctx *ctx@ = context to update |
| 265 | * @const void *p@ = input buffer |
| 266 | * @size_t sz@ = size of input |
| 267 | * |
| 268 | * Returns: --- |
| 269 | * |
| 270 | * Use: Feeds input data into a SHAKE context. The context must be |
| 271 | * in `absorbing' state. |
| 272 | */ |
| 273 | |
| 274 | extern void shake_hash(shake_ctx */*ctx*/, const void */*p*/, size_t /*sz*/); |
| 275 | |
| 276 | /* --- @shake_xof@ --- * |
| 277 | * |
| 278 | * Arguments: @shake_ctx *ctx@ = context to update |
| 279 | * |
| 280 | * Returns: --- |
| 281 | * |
| 282 | * Use: Switches the context into `squeezing' state. Use @shake_get@ |
| 283 | * or @shake_mask@ to extract data. |
| 284 | */ |
| 285 | |
| 286 | extern void shake_xof(shake_ctx */*ctx*/); |
| 287 | |
| 288 | /* --- @shake_get@ --- * |
| 289 | * |
| 290 | * Arguments: @shake_ctx *ctx@ = context to update |
| 291 | * @void *p@ = output buffer |
| 292 | * @size_t sz@ = size of output |
| 293 | * |
| 294 | * Returns: --- |
| 295 | * |
| 296 | * Use: Extracts output from a SHAKE context. The context must be |
| 297 | * in `squeezing' state. |
| 298 | */ |
| 299 | |
| 300 | extern void shake_get(shake_ctx */*ctx*/, void */*p*/, size_t /*sz*/); |
| 301 | |
| 302 | /* --- @shake_mask@ --- * |
| 303 | * |
| 304 | * Arguments: @shake_ctx *ctx@ = context to update |
| 305 | * @const void *src@ = pointer to source data, or null |
| 306 | * @void *dest@ = output buffer |
| 307 | * @size_t sz@ = size of output |
| 308 | * |
| 309 | * Returns: --- |
| 310 | * |
| 311 | * Use: Mask the @src@ data by XORing it with output from the SHAKE |
| 312 | * context, writing the result to @dest@. The @src@ and @dest |
| 313 | * buffers may be equal but must not otherwise overlap. The |
| 314 | * context must be in `squeezing' state. |
| 315 | */ |
| 316 | |
| 317 | extern void shake_mask(shake_ctx */*ctx*/, |
| 318 | const void */*src*/, void */*dest*/, size_t /*sz*/); |
| 319 | |
| 320 | /* --- @shake_done@ --- * |
| 321 | * |
| 322 | * Arguments: @shake_ctx *ctx@ = context to update |
| 323 | * @void *h@ = where to write the hash |
| 324 | * @size_t hsz@ = size of the hash to make |
| 325 | * |
| 326 | * Returns: --- |
| 327 | * |
| 328 | * Use: Switches the context into `squeezing' state. Use @shake_get@ |
| 329 | * or @shake_mask@ to extract data. |
| 330 | */ |
| 331 | |
| 332 | extern void shake_done(shake_ctx */*ctx*/, void */*h*/, size_t /*hsz*/); |
| 333 | |
| 334 | /* --- @shake{128,256}_rand@ --- * |
| 335 | * |
| 336 | * Arguments: @const void *k@ = pointer to seed material |
| 337 | * @size_t sz@ = size of the seed |
| 338 | * |
| 339 | * Returns: A pseudorandom generator with the given seed. |
| 340 | */ |
| 341 | |
| 342 | extern grand *shake128_rand(const void */*k*/, size_t /*sz*/); |
| 343 | extern grand *shake256_rand(const void */*k*/, size_t /*sz*/); |
| 344 | |
| 345 | /* --- @cshake{128,256}_rand@ --- * |
| 346 | * |
| 347 | * Arguments: @const void *func@ = function name |
| 348 | * @size_t fsz@ = length of function name |
| 349 | * @const void *perso@ = personalization string |
| 350 | * @size_t psz@ = length of personalization string |
| 351 | * @const void *k@ = pointer to seed material |
| 352 | * @size_t sz@ = size of the seed |
| 353 | * |
| 354 | * Returns: A pseudorandom generator with the given seed. |
| 355 | * |
| 356 | * Use: Note that with null @func@ and @perso@ strings, this is |
| 357 | * equivalent to @shake128_rand@ or @shake256_rand@. |
| 358 | */ |
| 359 | |
| 360 | extern grand *cshake128_rand(const void */*func*/, size_t /*fsz*/, |
| 361 | const void */*perso*/, size_t /*psz*/, |
| 362 | const void */*k*/, size_t /*sz*/); |
| 363 | |
| 364 | extern grand *cshake256_rand(const void */*func*/, size_t /*fsz*/, |
| 365 | const void */*perso*/, size_t /*psz*/, |
| 366 | const void */*k*/, size_t /*sz*/); |
| 367 | |
| 368 | /* --- Generic cipher interface --- */ |
| 369 | |
| 370 | extern const gccipher shake128_xof, shake256_xof; |
| 371 | extern const gchash shake128, shake256; |
| 372 | |
| 373 | /*----- The KMAC variable-length PRF --------------------------------------*/ |
| 374 | |
| 375 | typedef shake_ctx kmac_ctx; |
| 376 | |
| 377 | #define KMAC128_KEYSZ SHAKE128_KEYSZ |
| 378 | #define KMAC256_KEYSZ SHAKE256_KEYSZ |
| 379 | |
| 380 | #define KMAC128_TAGSZ 16 |
| 381 | #define KMAC256_TAGSZ 32 |
| 382 | |
| 383 | #define kmac128_keysz shake128_keysz |
| 384 | #define kmac256_keysz shake256_keysz |
| 385 | |
| 386 | /* --- @kmac{128,256}_init@ --- * |
| 387 | * |
| 388 | * Arguments: @kmac_ctx *ctx@ = pointer to context to fill in |
| 389 | * @const void *perso@ = personalization string, or null |
| 390 | * @size_t psz@ = length of personalization string |
| 391 | * @const void *k@ = pointer to key material |
| 392 | * @size_t sz@ = size of key material |
| 393 | * |
| 394 | * Returns: --- |
| 395 | * |
| 396 | * Use: Sets up a KMAC context. Set @tsz@ to zero for a flexible- |
| 397 | * length tag, which can be read using @kmac_get@. Use |
| 398 | * @kmac_hash@ to feed in the input message. |
| 399 | */ |
| 400 | |
| 401 | extern void kmac128_init(kmac_ctx */*ctx*/, |
| 402 | const void */*perso*/, size_t /*psz*/, |
| 403 | const void */*k*/, size_t /*sz*/); |
| 404 | extern void kmac256_init(kmac_ctx */*ctx*/, |
| 405 | const void */*perso*/, size_t /*psz*/, |
| 406 | const void */*k*/, size_t /*sz*/); |
| 407 | |
| 408 | /* --- @kmac_xof@ --- * |
| 409 | * |
| 410 | * Arguments: @kmac_ctx *ctx@ = pointer to context |
| 411 | * |
| 412 | * Returns: --- |
| 413 | * |
| 414 | * Use: Marks the end of the message to be processed. The output can |
| 415 | * be read using @kmac_get@. |
| 416 | */ |
| 417 | |
| 418 | void kmac_xof(kmac_ctx */*ctx*/); |
| 419 | |
| 420 | /* --- @kmac_done@ --- * |
| 421 | * |
| 422 | * Arguments: @kmac_ctx *ctx@ = pointer to context |
| 423 | * @void *h@ = where to put the tag |
| 424 | * @size_t hsz@ = size of tag to produce |
| 425 | * |
| 426 | * Returns: --- |
| 427 | * |
| 428 | * Use: Marks the end of the message to be processed and returns a |
| 429 | * tag. Note that the tag value is dependent on the output |
| 430 | * size. |
| 431 | */ |
| 432 | |
| 433 | void kmac_done(kmac_ctx */*ctx*/, void */*h*/, size_t /*hsz*/); |
| 434 | |
| 435 | /* --- Convenience aliases --- */ |
| 436 | |
| 437 | #define kmac_hash shake_hash |
| 438 | #define kmac_get shake_get |
| 439 | #define kmac_mask shake_mask |
| 440 | |
| 441 | /* --- @kmac{128,256}_rand@ --- * |
| 442 | * |
| 443 | * Arguments: @const void *perso@ = personalization string, or null |
| 444 | * @size_t psz@ = length of personalization string |
| 445 | * @const void *k@ = pointer to seed material |
| 446 | * @size_t sz@ = size of the seed |
| 447 | * |
| 448 | * Returns: A pseudorandom generator with the given key. |
| 449 | * |
| 450 | * Use: The generator processes an empty message by default, but this |
| 451 | * can be changed by seeding it. |
| 452 | */ |
| 453 | |
| 454 | extern grand *kmac128_rand(const void */*perso*/, size_t /*psz*/, |
| 455 | const void */*k*/, size_t /*sz*/); |
| 456 | extern grand *kmac256_rand(const void */*perso*/, size_t /*psz*/, |
| 457 | const void */*k*/, size_t /*sz*/); |
| 458 | |
| 459 | /* --- Generic MAC interface --- */ |
| 460 | |
| 461 | extern const gcmac kmac128, kmac256; |
| 462 | |
| 463 | /*----- That's all, folks -------------------------------------------------*/ |
| 464 | |
| 465 | #ifdef __cplusplus |
| 466 | } |
| 467 | #endif |
| 468 | |
| 469 | #endif |