chiark - git - mdw - catacomb/blob - symm/chacha.c

   1 /* -*-c-*-
   2  *
   3  * ChaCha stream cipher
   4  *
   5  * (c) 2015 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 /*----- Header files ------------------------------------------------------*/
  29
  30 #include "config.h"
  31
  32 #include <stdarg.h>
  33
  34 #include <mLib/bits.h>
  35
  36 #include "arena.h"
  37 #include "chacha.h"
  38 #include "chacha-core.h"
  39 #include "dispatch.h"
  40 #include "gcipher.h"
  41 #include "grand.h"
  42 #include "keysz.h"
  43 #include "paranoia.h"
  44
  45 /*----- Global variables --------------------------------------------------*/
  46
  47 const octet chacha_keysz[] = { KSZ_SET, 32, 16, 10, 0 };
  48
  49 /*----- The ChaCha core function and utilities ----------------------------*/
  50
  51 /* --- @core@ --- *
  52  *
  53  * Arguments:   @unsigned r@ = number of rounds
  54  *              @const chacha_matrix src@ = input matrix
  55  *              @chacha_matrix dest@ = where to put the output
  56  *
  57  * Returns:     ---
  58  *
  59  *
  60  * Use:         Apply the ChaCha/r core function to @src@, writing the
  61  *              result to @dest@.  This consists of @r@ rounds followed by
  62  *              the feedforward step.
  63  */
  64
  65 CPU_DISPATCH(static, (void), void, core,
  66              (unsigned r, const chacha_matrix src, chacha_matrix dest),
  67              (r, src, dest), pick_core, simple_core);
  68
  69 static void simple_core(unsigned r, const chacha_matrix src,
  70                         chacha_matrix dest)
  71   { CHACHA_nR(dest, src, r); CHACHA_FFWD(dest, src); }
  72
  73 #if CPUFAM_X86 || CPUFAM_AMD64
  74 extern core__functype chacha_core_x86ish_sse2;
  75 #endif
  76
  77 #if CPUFAM_ARMEL
  78 extern core__functype chacha_core_arm_neon;
  79 #endif
  80
  81 #if CPUFAM_ARM64
  82 extern core__functype chacha_core_arm64;
  83 #endif
  84
  85 static core__functype *pick_core(void)
  86 {
  87 #if CPUFAM_X86 || CPUFAM_AMD64
  88   DISPATCH_PICK_COND(chacha_core, chacha_core_x86ish_sse2,
  89                      cpu_feature_p(CPUFEAT_X86_SSE2));
  90 #endif
  91 #if CPUFAM_ARMEL
  92   DISPATCH_PICK_COND(chacha_core, chacha_core_arm_neon,
  93                      cpu_feature_p(CPUFEAT_ARM_NEON));
  94 #endif
  95 #if CPUFAM_ARM64
  96   DISPATCH_PICK_COND(chacha_core, chacha_core_arm64,
  97                      cpu_feature_p(CPUFEAT_ARM_NEON));
  98 #endif
  99   DISPATCH_PICK_FALLBACK(chacha_core, simple_core);
 100 }
 101
 102 /* --- @populate@ --- *
 103  *
 104  * Arguments:   @chacha_matrix a@ = a matrix to fill in
 105  *              @const void *key@ = pointer to key material
 106  *              @size_t ksz@ = size of key
 107  *
 108  * Returns:     ---
 109  *
 110  * Use:         Fills in a ChaCha matrix from the key, setting the
 111  *              appropriate constants according to the key length.  The nonce
 112  *              and position words are left uninitialized.
 113  */
 114
 115 static void populate(chacha_matrix a, const void *key, size_t ksz)
 116 {
 117   const octet *k = key;
 118
 119   KSZ_ASSERT(chacha, ksz);
 120
 121   a[ 4] = LOAD32_L(k +  0);
 122   a[ 5] = LOAD32_L(k +  4);
 123   if (ksz == 10) {
 124     a[ 6] = LOAD16_L(k +  8);
 125     a[ 7] = 0;
 126   } else {
 127     a[ 6] = LOAD32_L(k +  8);
 128     a[ 7] = LOAD32_L(k + 12);
 129   }
 130   if (ksz <= 16) {
 131     a[ 8] = a[ 4];
 132     a[ 9] = a[ 5];
 133     a[10] = a[ 6];
 134     a[11] = a[ 7];
 135     a[ 0] = CHACHA_A128;
 136     a[ 1] = CHACHA_B128;
 137     a[ 2] = ksz == 10 ? CHACHA_C80 : CHACHA_C128;
 138     a[ 3] = CHACHA_D128;
 139   } else {
 140     a[ 8] = LOAD32_L(k + 16);
 141     a[ 9] = LOAD32_L(k + 20);
 142     a[10] = LOAD32_L(k + 24);
 143     a[11] = LOAD32_L(k + 28);
 144     a[ 0] = CHACHA_A256;
 145     a[ 1] = CHACHA_B256;
 146     a[ 2] = CHACHA_C256;
 147     a[ 3] = CHACHA_D256;
 148   }
 149 }
 150
 151 /*----- ChaCha implementation ---------------------------------------------*/
 152
 153 /* --- @chacha_init@ --- *
 154  *
 155  * Arguments:   @chacha_ctx *ctx@ = context to fill in
 156  *              @const void *key@ = pointer to key material
 157  *              @size_t ksz@ = size of key (either 32 or 16)
 158  *              @const void *nonce@ = initial nonce, or null
 159  *
 160  * Returns:     ---
 161  *
 162  * Use:         Initializes a ChaCha context ready for use.
 163  */
 164
 165 void chacha_init(chacha_ctx *ctx, const void *key, size_t ksz,
 166                   const void *nonce)
 167 {
 168   static const octet zerononce[CHACHA_NONCESZ];
 169
 170   populate(ctx->a, key, ksz);
 171   chacha_setnonce(ctx, nonce ? nonce : zerononce);
 172 }
 173
 174 /* --- @chacha_setnonce{,_ietf}@ --- *
 175  *
 176  * Arguments:   @chacha_ctx *ctx@ = pointer to context
 177  *              @const void *nonce@ = the nonce (@CHACHA_NONCESZ@ or
 178  *                      @CHACHA_IETF_NONCESZ@ bytes)
 179  *
 180  * Returns:     ---
 181  *
 182  * Use:         Set a new nonce in the context @ctx@, e.g., for processing a
 183  *              different message.  The stream position is reset to zero (see
 184  *              @chacha_seek@ etc.).
 185  */
 186
 187 void chacha_setnonce(chacha_ctx *ctx, const void *nonce)
 188 {
 189   const octet *n = nonce;
 190
 191   ctx->a[14] = LOAD32_L(n + 0);
 192   ctx->a[15] = LOAD32_L(n + 4);
 193   chacha_seek(ctx, 0);
 194 }
 195
 196 void chacha_setnonce_ietf(chacha_ctx *ctx, const void *nonce)
 197 {
 198   const octet *n = nonce;
 199
 200   ctx->a[13] = LOAD32_L(n + 0);
 201   ctx->a[14] = LOAD32_L(n + 4);
 202   ctx->a[15] = LOAD32_L(n + 8);
 203   chacha_seek_ietf(ctx, 0);
 204 }
 205
 206 /* --- @chacha_seek{,u64,_ietf}@ --- *
 207  *
 208  * Arguments:   @chacha_ctx *ctx@ = pointer to context
 209  *              @unsigned long i@, @kludge64 i@, @uint32 i@ = new position
 210  *
 211  * Returns:     ---
 212  *
 213  * Use:         Sets a new stream position, in units of Chacha output
 214  *              blocks, which are @CHACHA_OUTSZ@ bytes each.  Byte
 215  *              granularity can be achieved by calling @chachaR_encrypt@
 216  *              appropriately.
 217  */
 218
 219 void chacha_seek(chacha_ctx *ctx, unsigned long i)
 220   { kludge64 ii; ASSIGN64(ii, i); chacha_seeku64(ctx, ii); }
 221
 222 void chacha_seeku64(chacha_ctx *ctx, kludge64 i)
 223 {
 224   ctx->a[12] = LO64(i); ctx->a[13] = HI64(i);
 225   ctx->bufi = CHACHA_OUTSZ;
 226 }
 227
 228 void chacha_seek_ietf(chacha_ctx *ctx, uint32 i)
 229   { ctx->a[12] = i; }
 230
 231 /* --- @chacha_tell{,u64,_ietf}@ --- *
 232  *
 233  * Arguments:   @chacha_ctx *ctx@ = pointer to context
 234  *
 235  * Returns:     The current position in the output stream, in blocks,
 236  *              rounding upwards.
 237  */
 238
 239 unsigned long chacha_tell(chacha_ctx *ctx)
 240   { kludge64 i = chacha_tellu64(ctx); return (GET64(unsigned long, i)); }
 241
 242 kludge64 chacha_tellu64(chacha_ctx *ctx)
 243   { kludge64 i; SET64(i, ctx->a[13], ctx->a[12]); return (i); }
 244
 245 uint32 chacha_tell_ietf(chacha_ctx *ctx)
 246   { return (ctx->a[12]); }
 247
 248 /* --- @chacha{20,12,8}_encrypt@ --- *
 249  *
 250  * Arguments:   @chacha_ctx *ctx@ = pointer to context
 251  *              @const void *src@ = source buffer (or null)
 252  *              @void *dest@ = destination buffer (or null)
 253  *              @size_t sz@ = size of the buffers
 254  *
 255  * Returns:     ---
 256  *
 257  * Use:         Encrypts or decrypts @sz@ bytes of data from @src@ to @dest@.
 258  *              ChaCha works by XORing plaintext with a keystream, so
 259  *              encryption and decryption are the same operation.  If @dest@
 260  *              is null then ignore @src@ and skip @sz@ bytes of the
 261  *              keystream.  If @src@ is null, then just write the keystream
 262  *              to @dest@.
 263  */
 264
 265 #define CHACHA_ENCRYPT(r, ctx, src, dest, sz)                           \
 266   chacha##r##_encrypt(ctx, src, dest, sz)
 267 #define DEFENCRYPT(r)                                                   \
 268   void CHACHA_ENCRYPT(r, chacha_ctx *ctx, const void *src,              \
 269                       void *dest, size_t sz)                            \
 270   {                                                                     \
 271     chacha_matrix b;                                                    \
 272     const octet *s = src;                                               \
 273     octet *d = dest;                                                    \
 274     size_t n;                                                           \
 275     kludge64 pos, delta;                                                \
 276                                                                         \
 277     SALSA20_OUTBUF(ctx, d, s, sz);                                      \
 278     if (!sz) return;                                                    \
 279                                                                         \
 280     if (!dest) {                                                        \
 281       n = sz/CHACHA_OUTSZ;                                              \
 282       pos = chacha_tellu64(ctx);                                        \
 283       ASSIGN64(delta, n);                                               \
 284       ADD64(pos, pos, delta);                                           \
 285       chacha_seeku64(ctx, pos);                                         \
 286       sz = sz%CHACHA_OUTSZ;                                             \
 287     } else if (!src) {                                                  \
 288       while (sz >= CHACHA_OUTSZ) {                                      \
 289         core(r, ctx->a, b);                                             \
 290         CHACHA_STEP(ctx->a);                                            \
 291         SALSA20_GENFULL(b, d);                                          \
 292         sz -= CHACHA_OUTSZ;                                             \
 293       }                                                                 \
 294     } else {                                                            \
 295       while (sz >= CHACHA_OUTSZ) {                                      \
 296         core(r, ctx->a, b);                                             \
 297         CHACHA_STEP(ctx->a);                                            \
 298         SALSA20_MIXFULL(b, d, s);                                       \
 299         sz -= CHACHA_OUTSZ;                                             \
 300       }                                                                 \
 301     }                                                                   \
 302                                                                         \
 303     if (sz) {                                                           \
 304       core(r, ctx->a, b);                                               \
 305       CHACHA_STEP(ctx->a);                                              \
 306       SALSA20_PREPBUF(ctx, b);                                          \
 307       SALSA20_OUTBUF(ctx, d, s, sz);                                    \
 308       assert(!sz);                                                      \
 309     }                                                                   \
 310   }
 311 CHACHA_VARS(DEFENCRYPT)
 312
 313 /*----- HChaCha implementation --------------------------------------------*/
 314
 315 #define HCHACHA_RAW(r, ctx, src, dest) hchacha##r##_raw(ctx, src, dest)
 316 #define HCHACHA_PRF(r, ctx, src, dest) hchacha##r##_prf(ctx, src, dest)
 317
 318 /* --- @hchacha{20,12,8}_prf@ --- *
 319  *
 320  * Arguments:   @chacha_ctx *ctx@ = pointer to context
 321  *              @const void *src@ = the input (@HCHACHA_INSZ@ bytes)
 322  *              @void *dest@ = the output (@HCHACHA_OUTSZ@ bytes)
 323  *
 324  * Returns:     ---
 325  *
 326  * Use:         Apply the HChacha/r pseudorandom function to @src@, writing
 327  *              the result to @out@.
 328  */
 329
 330 #define DEFHCHACHA(r)                                                   \
 331   static void HCHACHA_RAW(r, chacha_matrix k,                           \
 332                           const uint32 *src, uint32 *dest)              \
 333   {                                                                     \
 334     chacha_matrix a;                                                    \
 335     int i;                                                              \
 336                                                                         \
 337     /* --- HChaCha, computed from full ChaCha --- *                     \
 338      *                                                                  \
 339      * The security proof makes use of the fact that HChaCha (i.e.,     \
 340      * without the final feedforward step) can be computed from full    \
 341      * ChaCha using only knowledge of the non-secret input.  I don't    \
 342      * want to compromise the performance of the main function by       \
 343      * making the feedforward step separate, but this operation is less \
 344      * speed critical, so we do it the harder way.                      \
 345      */                                                                 \
 346                                                                         \
 347     for (i = 0; i < 4; i++) k[12 + i] = src[i];                         \
 348     core(r, k, a);                                                      \
 349     for (i = 0; i < 8; i++) dest[i] = a[(i + 4)^4] - k[(i + 4)^4];      \
 350   }                                                                     \
 351                                                                         \
 352   void HCHACHA_PRF(r, chacha_ctx *ctx, const void *src, void *dest)     \
 353   {                                                                     \
 354     const octet *s = src;                                               \
 355     octet *d = dest;                                                    \
 356     uint32 in[4], out[8];                                               \
 357     int i;                                                              \
 358                                                                         \
 359     for (i = 0; i < 4; i++) in[i] = LOAD32_L(s + 4*i);                  \
 360     HCHACHA_RAW(r, ctx->a, in, out);                                    \
 361     for (i = 0; i < 8; i++) STORE32_L(d + 4*i, out[i]);                 \
 362   }
 363 CHACHA_VARS(DEFHCHACHA)
 364
 365 /*----- XChaCha implementation -------------------------------------------*/
 366
 367 /* --- Some convenient macros for naming functions --- *
 368  *
 369  * Because the crypto core is involved in XChaCha/r's per-nonce setup, we
 370  * need to take an interest in the number of rounds in most of the various
 371  * functions, and it will probably help if we distinguish the context
 372  * structures for the various versions.
 373  */
 374
 375 #define XCHACHA_CTX(r) xchacha##r##_ctx
 376 #define XCHACHA_INIT(r, ctx, k, ksz, n) xchacha##r##_init(ctx, k, ksz, n)
 377 #define XCHACHA_SETNONCE(r, ctx, n) xchacha##r##_setnonce(ctx, n)
 378 #define XCHACHA_SEEK(r, ctx, i) xchacha##r##_seek(ctx, i)
 379 #define XCHACHA_SEEKU64(r, ctx, i) xchacha##r##_seeku64(ctx, i)
 380 #define XCHACHA_TELL(r, ctx) xchacha##r##_tell(ctx)
 381 #define XCHACHA_TELLU64(r, ctx) xchacha##r##_tellu64(ctx)
 382 #define XCHACHA_ENCRYPT(r, ctx, src, dest, sz)                          \
 383   xchacha##r##_encrypt(ctx, src, dest, sz)
 384
 385 /* --- @xchacha{20,12,8}_init@ --- *
 386  *
 387  * Arguments:   @xchachaR_ctx *ctx@ = the context to fill in
 388  *              @const void *key@ = pointer to key material
 389  *              @size_t ksz@ = size of key (either 32 or 16)
 390  *              @const void *nonce@ = initial nonce, or null
 391  *
 392  * Returns:     ---
 393  *
 394  * Use:         Initializes an XChaCha/r context ready for use.
 395  *
 396  *              There is a different function for each number of rounds,
 397  *              unlike for plain ChaCha.
 398  */
 399
 400 #define DEFXINIT(r)                                                     \
 401   void XCHACHA_INIT(r, XCHACHA_CTX(r) *ctx,                             \
 402                     const void *key, size_t ksz, const void *nonce)     \
 403   {                                                                     \
 404     static const octet zerononce[XCHACHA_NONCESZ];                      \
 405                                                                         \
 406     populate(ctx->k, key, ksz);                                         \
 407     ctx->s.a[ 0] = CHACHA_A256;                                         \
 408     ctx->s.a[ 1] = CHACHA_B256;                                         \
 409     ctx->s.a[ 2] = CHACHA_C256;                                         \
 410     ctx->s.a[ 3] = CHACHA_D256;                                         \
 411     XCHACHA_SETNONCE(r, ctx, nonce ? nonce : zerononce);                \
 412   }
 413 CHACHA_VARS(DEFXINIT)
 414
 415 /* --- @xchacha{20,12,8}_setnonce@ --- *
 416  *
 417  * Arguments:   @xchachaR_ctx *ctx@ = pointer to context
 418  *              @const void *nonce@ = the nonce (@XCHACHA_NONCESZ@ bytes)
 419  *
 420  * Returns:     ---
 421  *
 422  * Use:         Set a new nonce in the context @ctx@, e.g., for processing a
 423  *              different message.  The stream position is reset to zero (see
 424  *              @chacha_seek@ etc.).
 425  *
 426  *              There is a different function for each number of rounds,
 427  *              unlike for plain ChaCha.
 428  */
 429
 430 #define DEFXNONCE(r)                                                    \
 431   void XCHACHA_SETNONCE(r, XCHACHA_CTX(r) *ctx, const void *nonce)      \
 432   {                                                                     \
 433     const octet *n = nonce;                                             \
 434     uint32 in[4];                                                       \
 435     int i;                                                              \
 436                                                                         \
 437     for (i = 0; i < 4; i++) in[i] = LOAD32_L(n + 4*i);                  \
 438     HCHACHA_RAW(r, ctx->k, in, ctx->s.a + 4);                           \
 439     chacha_setnonce(&ctx->s, n + 16);                                   \
 440   }
 441 CHACHA_VARS(DEFXNONCE)
 442
 443 /* --- @xchacha{20,12,8}_seek{,u64}@ --- *
 444  *
 445  * Arguments:   @xchachaR_ctx *ctx@ = pointer to context
 446  *              @unsigned long i@, @kludge64 i@ = new position to set
 447  *
 448  * Returns:     ---
 449  *
 450  * Use:         Sets a new stream position, in units of ChaCha output
 451  *              blocks, which are @XCHACHA_OUTSZ@ bytes each.  Byte
 452  *              granularity can be achieved by calling @xchachaR_encrypt@
 453  *              appropriately.
 454  *
 455  *              There is a different function for each number of rounds,
 456  *              unlike for plain ChaCha, because the context structures are
 457  *              different.
 458  */
 459
 460 /* --- @xchacha{20,12,8}_tell{,u64}@ --- *
 461  *
 462  * Arguments:   @chacha_ctx *ctx@ = pointer to context
 463  *
 464  * Returns:     The current position in the output stream, in blocks,
 465  *              rounding upwards.
 466  *
 467  *              There is a different function for each number of rounds,
 468  *              unlike for plain ChaCha, because the context structures are
 469  *              different.
 470  */
 471
 472 /* --- @xchacha{20,12,8}_encrypt@ --- *
 473  *
 474  * Arguments:   @xchachaR_ctx *ctx@ = pointer to context
 475  *              @const void *src@ = source buffer (or null)
 476  *              @void *dest@ = destination buffer (or null)
 477  *              @size_t sz@ = size of the buffers
 478  *
 479  * Returns:     ---
 480  *
 481  * Use:         Encrypts or decrypts @sz@ bytes of data from @src@ to @dest@.
 482  *              XChaCha works by XORing plaintext with a keystream, so
 483  *              encryption and decryption are the same operation.  If @dest@
 484  *              is null then ignore @src@ and skip @sz@ bytes of the
 485  *              keystream.  If @src@ is null, then just write the keystream
 486  *              to @dest@.
 487  */
 488
 489 #define DEFXPASSTHRU(r)                                                 \
 490   void XCHACHA_SEEK(r, XCHACHA_CTX(r) *ctx, unsigned long i)            \
 491     { chacha_seek(&ctx->s, i); }                                        \
 492   void XCHACHA_SEEKU64(r, XCHACHA_CTX(r) *ctx, kludge64 i)              \
 493     { chacha_seeku64(&ctx->s, i); }                                     \
 494   unsigned long XCHACHA_TELL(r, XCHACHA_CTX(r) *ctx)                    \
 495     { return chacha_tell(&ctx->s); }                                    \
 496   kludge64 XCHACHA_TELLU64(r, XCHACHA_CTX(r) *ctx)                      \
 497     { return chacha_tellu64(&ctx->s); }                                 \
 498   void XCHACHA_ENCRYPT(r, XCHACHA_CTX(r) *ctx,                          \
 499                         const void *src, void *dest, size_t sz)         \
 500     { CHACHA_ENCRYPT(r, &ctx->s, src, dest, sz); }
 501 CHACHA_VARS(DEFXPASSTHRU)
 502
 503 /*----- Generic cipher interface ------------------------------------------*/
 504
 505 typedef struct gctx { gcipher c; chacha_ctx ctx; } gctx;
 506
 507 static void gsetiv(gcipher *c, const void *iv)
 508   { gctx *g = (gctx *)c; chacha_setnonce(&g->ctx, iv); }
 509
 510 static void gsetiv_ietf(gcipher *c, const void *iv)
 511   { gctx *g = (gctx *)c; chacha_setnonce_ietf(&g->ctx, iv); }
 512
 513 static void gdestroy(gcipher *c)
 514   { gctx *g = (gctx *)c; BURN(*g); S_DESTROY(g); }
 515
 516 static gcipher *ginit(const void *k, size_t sz, const gcipher_ops *ops)
 517 {
 518   gctx *g = S_CREATE(gctx);
 519   g->c.ops = ops;
 520   chacha_init(&g->ctx, k, sz, 0);
 521   return (&g->c);
 522 }
 523
 524 #define DEFGCIPHER(r)                                                   \
 525                                                                         \
 526   static const gcipher_ops gops_##r, gops_##r##_ietf;                   \
 527                                                                         \
 528   static gcipher *ginit_##r(const void *k, size_t sz)                   \
 529     { return (ginit(k, sz, &gops_##r)); }                               \
 530                                                                         \
 531   static gcipher *ginit_##r##_ietf(const void *k, size_t sz)            \
 532     { return (ginit(k, sz, &gops_##r##_ietf)); }                        \
 533                                                                         \
 534   static void gencrypt_##r(gcipher *c, const void *s,                   \
 535                            void *t, size_t sz)                          \
 536     { gctx *g = (gctx *)c; CHACHA_ENCRYPT(r, &g->ctx, s, t, sz); }      \
 537                                                                         \
 538   static const gcipher_ops gops_##r = {                                 \
 539     &chacha##r,                                                         \
 540     gencrypt_##r, gencrypt_##r, gdestroy, gsetiv, 0                     \
 541   };                                                                    \
 542                                                                         \
 543   static const gcipher_ops gops_##r##_ietf = {                          \
 544     &chacha##r##_ietf,                                                  \
 545     gencrypt_##r, gencrypt_##r, gdestroy, gsetiv_ietf, 0                \
 546   };                                                                    \
 547                                                                         \
 548   const gccipher chacha##r = {                                          \
 549     "chacha" #r, chacha_keysz,                                          \
 550     CHACHA_NONCESZ, ginit_##r                                           \
 551   };                                                                    \
 552                                                                         \
 553   const gccipher chacha##r##_ietf = {                                   \
 554     "chacha" #r "-ietf", chacha_keysz,                                  \
 555     CHACHA_IETF_NONCESZ, ginit_##r##_ietf                               \
 556   };
 557
 558 CHACHA_VARS(DEFGCIPHER)
 559
 560 #define DEFGXCIPHER(r)                                                  \
 561                                                                         \
 562   typedef struct { gcipher c; XCHACHA_CTX(r) ctx; } gxctx_##r;          \
 563                                                                         \
 564   static void gxsetiv_##r(gcipher *c, const void *iv)                   \
 565     { gxctx_##r *g = (gxctx_##r *)c; XCHACHA_SETNONCE(r, &g->ctx, iv); } \
 566                                                                         \
 567   static void gxdestroy_##r(gcipher *c)                                 \
 568     { gxctx_##r *g = (gxctx_##r *)c; BURN(*g); S_DESTROY(g); }          \
 569                                                                         \
 570   static const gcipher_ops gxops_##r;                                   \
 571                                                                         \
 572   static gcipher *gxinit_##r(const void *k, size_t sz)                  \
 573   {                                                                     \
 574     gxctx_##r *g = S_CREATE(gxctx_##r);                                 \
 575     g->c.ops = &gxops_##r;                                              \
 576     XCHACHA_INIT(r, &g->ctx, k, sz, 0);                                 \
 577     return (&g->c);                                                     \
 578   }                                                                     \
 579                                                                         \
 580   static void gxencrypt_##r(gcipher *c, const void *s,                  \
 581                             void *t, size_t sz)                         \
 582   {                                                                     \
 583     gxctx_##r *g = (gxctx_##r *)c;                                      \
 584     XCHACHA_ENCRYPT(r, &g->ctx, s, t, sz);                              \
 585   }                                                                     \
 586                                                                         \
 587   static const gcipher_ops gxops_##r = {                                \
 588     &xchacha##r,                                                        \
 589     gxencrypt_##r, gxencrypt_##r, gxdestroy_##r, gxsetiv_##r, 0         \
 590   };                                                                    \
 591                                                                         \
 592   const gccipher xchacha##r = {                                         \
 593     "xchacha" #r, chacha_keysz,                                         \
 594     XCHACHA_NONCESZ, gxinit_##r                                         \
 595   };
 596
 597 CHACHA_VARS(DEFGXCIPHER)
 598
 599 /*----- Generic random number generator interface -------------------------*/
 600
 601 typedef struct grops {
 602   size_t noncesz;
 603   void (*seek)(void *, kludge64);
 604   kludge64 (*tell)(void *);
 605   void (*setnonce)(void *, const void *);
 606   void (*generate)(void *, void *, size_t);
 607 } grops;
 608
 609 typedef struct grbasectx {
 610   grand r;
 611   const grops *ops;
 612 } grbasectx;
 613
 614 static int grmisc(grand *r, unsigned op, ...)
 615 {
 616   octet buf[XCHACHA_NONCESZ];
 617   grbasectx *g = (grbasectx *)r;
 618   grand *rr;
 619   const octet *p;
 620   size_t sz;
 621   uint32 i;
 622   unsigned long ul;
 623   kludge64 pos;
 624   va_list ap;
 625   int rc = 0;
 626
 627   va_start(ap, op);
 628
 629   switch (op) {
 630     case GRAND_CHECK:
 631       switch (va_arg(ap, unsigned)) {
 632         case GRAND_CHECK:
 633         case GRAND_SEEDINT:
 634         case GRAND_SEEDUINT32:
 635         case GRAND_SEEDBLOCK:
 636         case GRAND_SEEDRAND:
 637         case CHACHA_SEEK:
 638         case CHACHA_SEEKU64:
 639         case CHACHA_TELL:
 640         case CHACHA_TELLU64:
 641           rc = 1;
 642           break;
 643         default:
 644           rc = 0;
 645           break;
 646       }
 647       break;
 648
 649     case GRAND_SEEDINT:
 650       i = va_arg(ap, unsigned); STORE32_L(buf, i);
 651       memset(buf + 4, 0, g->ops->noncesz - 4);
 652       g->ops->setnonce(g, buf);
 653       break;
 654     case GRAND_SEEDUINT32:
 655       i = va_arg(ap, uint32); STORE32_L(buf, i);
 656       memset(buf + 4, 0, g->ops->noncesz - 4);
 657       g->ops->setnonce(g, buf);
 658       break;
 659     case GRAND_SEEDBLOCK:
 660       p = va_arg(ap, const void *);
 661       sz = va_arg(ap, size_t);
 662       if (sz < g->ops->noncesz) {
 663         memcpy(buf, p, sz);
 664         memset(buf + sz, 0, g->ops->noncesz - sz);
 665         p = buf;
 666       }
 667       g->ops->setnonce(g, p);
 668       break;
 669     case GRAND_SEEDRAND:
 670       rr = va_arg(ap, grand *);
 671       rr->ops->fill(rr, buf, g->ops->noncesz);
 672       g->ops->setnonce(g, buf);
 673       break;
 674     case CHACHA_SEEK:
 675       ul = va_arg(ap, unsigned long); ASSIGN64(pos, ul);
 676       g->ops->seek(g, pos);
 677       break;
 678     case CHACHA_SEEKU64:
 679       pos = va_arg(ap, kludge64);
 680       g->ops->seek(g, pos);
 681       break;
 682     case CHACHA_TELL:
 683       pos = g->ops->tell(g);
 684       *va_arg(ap, unsigned long *) = GET64(unsigned long, pos);
 685       break;
 686     case CHACHA_TELLU64:
 687       *va_arg(ap, kludge64 *) = g->ops->tell(g);
 688       break;
 689     default:
 690       GRAND_BADOP;
 691       break;
 692   }
 693
 694   return (rc);
 695 }
 696
 697 static octet grbyte(grand *r)
 698 {
 699   grbasectx *g = (grbasectx *)r;
 700   octet o;
 701   g->ops->generate(g, &o, 1);
 702   return (o);
 703 }
 704
 705 static uint32 grword(grand *r)
 706 {
 707   grbasectx *g = (grbasectx *)r;
 708   octet b[4];
 709   g->ops->generate(g, b, sizeof(b));
 710   return (LOAD32_L(b));
 711 }
 712
 713 static void grfill(grand *r, void *p, size_t sz)
 714 {
 715   grbasectx *g = (grbasectx *)r;
 716   g->ops->generate(r, p, sz);
 717 }
 718
 719 typedef struct grctx {
 720   grbasectx r;
 721   chacha_ctx ctx;
 722 } grctx;
 723
 724 static void gr_seek(void *r, kludge64 pos)
 725   { grctx *g = r; chacha_seeku64(&g->ctx, pos); }
 726
 727 static void gr_seek_ietf(void *r, kludge64 pos)
 728   { grctx *g = r; chacha_seek_ietf(&g->ctx, LO64(pos)); }
 729
 730 static kludge64 gr_tell(void *r)
 731   { grctx *g = r; return (chacha_tellu64(&g->ctx)); }
 732
 733 static kludge64 gr_tell_ietf(void *r)
 734 {
 735   grctx *g = r;
 736   kludge64 pos;
 737
 738   SET64(pos, 0, chacha_tell_ietf(&g->ctx));
 739   return (pos);
 740 }
 741
 742 static void gr_setnonce(void *r, const void *n)
 743   { grctx *g = r; chacha_setnonce(&g->ctx, n); }
 744
 745 static void gr_setnonce_ietf(void *r, const void *n)
 746   { grctx *g = r; chacha_setnonce_ietf(&g->ctx, n); }
 747
 748 static void grdestroy(grand *r)
 749   { grctx *g = (grctx *)r; BURN(*g); S_DESTROY(g); }
 750
 751 static grand *grinit(const void *k, size_t ksz, const void *n,
 752                      const grand_ops *ops, const grops *myops)
 753 {
 754     grctx *g = S_CREATE(grctx);
 755     g->r.r.ops = ops;
 756     g->r.ops = myops;
 757     chacha_init(&g->ctx, k, ksz, 0);
 758     if (n) myops->setnonce(g, n);
 759     return (&g->r.r);
 760 }
 761
 762 #define DEFGRAND(rr)                                                    \
 763                                                                         \
 764   static void gr_generate_##rr(void *r, void *b, size_t sz)             \
 765     { grctx *g = r; CHACHA_ENCRYPT(rr, &g->ctx, 0, b, sz); }            \
 766                                                                         \
 767   static const grops grops_##rr =                                       \
 768     { CHACHA_NONCESZ, gr_seek, gr_tell,                                 \
 769       gr_setnonce, gr_generate_##rr };                                  \
 770                                                                         \
 771   static const grops grops_##rr##_ietf =                                \
 772     { CHACHA_IETF_NONCESZ, gr_seek_ietf, gr_tell_ietf,                  \
 773       gr_setnonce_ietf, gr_generate_##rr };                             \
 774                                                                         \
 775   static const grand_ops grops_rand_##rr = {                            \
 776     "chacha" #rr, GRAND_CRYPTO, 0,                                      \
 777     grmisc, grdestroy, grword,                                          \
 778     grbyte, grword, grand_defaultrange, grfill                          \
 779   };                                                                    \
 780                                                                         \
 781   static const grand_ops grops_rand_##rr##_ietf = {                     \
 782     "chacha" #rr "-ietf", GRAND_CRYPTO, 0,                              \
 783     grmisc, grdestroy, grword,                                          \
 784     grbyte, grword, grand_defaultrange, grfill                          \
 785   };                                                                    \
 786                                                                         \
 787   grand *chacha##rr##_rand(const void *k, size_t ksz, const void *n)    \
 788     { return (grinit(k, ksz, n, &grops_rand_##rr, &grops_##rr)); }      \
 789                                                                         \
 790   grand *chacha##rr##_ietf_rand(const void *k, size_t ksz,              \
 791                                 const void *n)                          \
 792   {                                                                     \
 793     return (grinit(k, ksz, n,                                           \
 794                    &grops_rand_##rr##_ietf,                             \
 795                    &grops_##rr##_ietf));                                \
 796   }
 797
 798 CHACHA_VARS(DEFGRAND)
 799
 800 #define DEFXGRAND(rr)                                                   \
 801                                                                         \
 802   typedef struct grxctx_##rr {                                          \
 803     grbasectx r;                                                        \
 804     XCHACHA_CTX(rr) ctx;                                                \
 805   } grxctx_##rr;                                                        \
 806                                                                         \
 807   static void grx_seek_##rr(void *r, kludge64 pos)                      \
 808     { grxctx_##rr *g = r; XCHACHA_SEEKU64(rr, &g->ctx, pos); }          \
 809                                                                         \
 810   static kludge64 grx_tell_##rr(void *r)                                \
 811     { grxctx_##rr *g = r; return (XCHACHA_TELLU64(rr, &g->ctx)); }      \
 812                                                                         \
 813   static void grx_setnonce_##rr(void *r, const void *n)                 \
 814     { grxctx_##rr *g = r; XCHACHA_SETNONCE(rr, &g->ctx, n); }           \
 815                                                                         \
 816   static void grxdestroy_##rr(grand *r)                                 \
 817     { grxctx_##rr *g = (grxctx_##rr *)r; BURN(*g); S_DESTROY(g); }      \
 818                                                                         \
 819   static void grx_generate_##rr(void *r, void *b, size_t sz)            \
 820     { grxctx_##rr *g = r; XCHACHA_ENCRYPT(rr, &g->ctx, 0, b, sz); }     \
 821                                                                         \
 822   static const grops grxops_##rr =                                      \
 823     { XCHACHA_NONCESZ, grx_seek_##rr, grx_tell_##rr,                    \
 824       grx_setnonce_##rr, grx_generate_##rr };                           \
 825                                                                         \
 826   static const grand_ops grxops_rand_##rr = {                           \
 827     "xchacha" #rr, GRAND_CRYPTO, 0,                                     \
 828     grmisc, grxdestroy_##rr, grword,                                    \
 829     grbyte, grword, grand_defaultrange, grfill                          \
 830   };                                                                    \
 831                                                                         \
 832   grand *xchacha##rr##_rand(const void *k, size_t ksz, const void *n)   \
 833   {                                                                     \
 834     grxctx_##rr *g = S_CREATE(grxctx_##rr);                             \
 835     g->r.r.ops = &grxops_rand_##rr;                                     \
 836     g->r.ops = &grxops_##rr;                                            \
 837     XCHACHA_INIT(rr, &g->ctx, k, ksz, n);                               \
 838     return (&g->r.r);                                                   \
 839   }
 840 CHACHA_VARS(DEFXGRAND)
 841
 842 /*----- Test rig ----------------------------------------------------------*/
 843
 844 #ifdef TEST_RIG
 845
 846 #include <stdio.h>
 847 #include <string.h>
 848
 849 #include <mLib/quis.h>
 850 #include <mLib/testrig.h>
 851
 852 #define DEFVCORE(r)                                                     \
 853   static int v_core_##r(dstr *v)                                        \
 854   {                                                                     \
 855     chacha_matrix a, b;                                                 \
 856     dstr d = DSTR_INIT;                                                 \
 857     int i, n;                                                           \
 858     int ok = 1;                                                         \
 859                                                                         \
 860     DENSURE(&d, CHACHA_OUTSZ); d.len = CHACHA_OUTSZ;                    \
 861     n = *(int *)v[0].buf;                                               \
 862     for (i = 0; i < CHACHA_OUTSZ/4; i++)                                \
 863       a[i] = LOAD32_L(v[1].buf + 4*i);                                  \
 864     for (i = 0; i < n; i++) {                                           \
 865       core(r, a, b);                                                    \
 866       memcpy(a, b, sizeof(a));                                          \
 867     }                                                                   \
 868     for (i = 0; i < CHACHA_OUTSZ/4; i++) STORE32_L(d.buf + 4*i, a[i]);  \
 869                                                                         \
 870     if (d.len != v[2].len || memcmp(d.buf, v[2].buf, v[2].len) != 0) {  \
 871       ok = 0;                                                           \
 872       printf("\nfail core:"                                             \
 873              "\n\titerations = %d"                                      \
 874              "\n\tin       = ", n);                                     \
 875       type_hex.dump(&v[1], stdout);                                     \
 876       printf("\n\texpected   = ");                                      \
 877       type_hex.dump(&v[2], stdout);                                     \
 878       printf("\n\tcalculated = ");                                      \
 879       type_hex.dump(&d, stdout);                                        \
 880       putchar('\n');                                                    \
 881     }                                                                   \
 882                                                                         \
 883     dstr_destroy(&d);                                                   \
 884     return (ok);                                                        \
 885   }
 886 CHACHA_VARS(DEFVCORE)
 887
 888 #define CHACHA_CTX(r) chacha_ctx
 889
 890 #define CHACHA_TESTSETUP(r, ctx, k, ksz, n, nsz, p, psz) do {           \
 891   kludge64 pos64;                                                       \
 892   chacha_init(ctx, k, ksz, 0);                                          \
 893   if (nsz == 8) chacha_setnonce(ctx, n);                                \
 894   else if (nsz == 12) chacha_setnonce_ietf(ctx, n);                     \
 895   if (psz == 8) { LOAD64_(pos64, p); chacha_seeku64(ctx, pos64); }      \
 896   else if (psz == 4) chacha_seek_ietf(ctx, LOAD32(p));                  \
 897 } while (0)
 898
 899 #define XCHACHA_TESTSETUP(r, ctx, k, ksz, n, nsz, p, psz) do {          \
 900   kludge64 pos64;                                                       \
 901   XCHACHA_INIT(r, ctx, k, ksz, 0);                                      \
 902   if (nsz == 24) XCHACHA_SETNONCE(r, ctx, n);                           \
 903   if (psz == 8) { LOAD64_(pos64, p); xchacha##r##_seeku64(ctx, pos64); } \
 904 } while (0)
 905
 906 #define DEFxVENC(base, BASE, r)                                         \
 907   static int v_encrypt_##base##_##r(dstr *v)                            \
 908   {                                                                     \
 909     BASE##_CTX(r) ctx;                                                  \
 910     dstr d = DSTR_INIT;                                                 \
 911     const octet *p, *p0;                                                \
 912     octet *q;                                                           \
 913     size_t sz, sz0, step;                                               \
 914     unsigned long skip;                                                 \
 915     int ok = 1;                                                         \
 916                                                                         \
 917     if (v[4].len) { p0 = (const octet *)v[4].buf; sz0 = v[4].len; }     \
 918     else { p0 = 0; sz0 = v[5].len; }                                    \
 919     DENSURE(&d, sz0); d.len = sz0;                                      \
 920     skip = *(unsigned long *)v[3].buf;                                  \
 921                                                                         \
 922     step = 0;                                                           \
 923     while (step < sz0 + skip) {                                         \
 924       step = step ? 3*step + 4 : 1;                                     \
 925       if (step > sz0 + skip) step = sz0 + skip;                         \
 926       BASE##_TESTSETUP(r, &ctx, v[0].buf, v[0].len,                     \
 927                        v[1].buf, v[1].len, v[2].buf, v[2].len);         \
 928                                                                         \
 929       for (sz = skip; sz >= step; sz -= step)                           \
 930         BASE##_ENCRYPT(r, &ctx, 0, 0, step);                            \
 931       if (sz) BASE##_ENCRYPT(r, &ctx, 0, 0, sz);                        \
 932       for (p = p0, q = (octet *)d.buf, sz = sz0;                        \
 933            sz >= step;                                                  \
 934            sz -= step, q += step) {                                     \
 935         BASE##_ENCRYPT(r, &ctx, p, q, step);                            \
 936         if (p) p += step;                                               \
 937       }                                                                 \
 938       if (sz) BASE##_ENCRYPT(r, &ctx, p, q, sz);                        \
 939                                                                         \
 940       if (d.len != v[5].len || memcmp(d.buf, v[5].buf, v[5].len) != 0) { \
 941         ok = 0;                                                         \
 942         printf("\nfail encrypt:"                                        \
 943                "\n\tstep           = %lu"                               \
 944                "\n\tkey    = ", (unsigned long)step);                   \
 945         type_hex.dump(&v[0], stdout);                                   \
 946         printf("\n\tnonce          = ");                                \
 947         type_hex.dump(&v[1], stdout);                                   \
 948         printf("\n\tposition   = ");                                    \
 949         type_hex.dump(&v[2], stdout);                                   \
 950         printf("\n\tskip           = %lu", skip);                       \
 951         printf("\n\tmessage    = ");                                    \
 952         type_hex.dump(&v[4], stdout);                                   \
 953         printf("\n\texpected   = ");                                    \
 954         type_hex.dump(&v[5], stdout);                                   \
 955         printf("\n\tcalculated = ");                                    \
 956         type_hex.dump(&d, stdout);                                      \
 957         putchar('\n');                                                  \
 958       }                                                                 \
 959     }                                                                   \
 960                                                                         \
 961     dstr_destroy(&d);                                                   \
 962     return (ok);                                                        \
 963   }
 964 #define DEFVENC(r) DEFxVENC(chacha, CHACHA, r)
 965 #define DEFXVENC(r) DEFxVENC(xchacha, XCHACHA, r)
 966 CHACHA_VARS(DEFVENC)
 967 CHACHA_VARS(DEFXVENC)
 968
 969 static test_chunk defs[] = {
 970 #define DEFxTAB(base, r)                                                \
 971   { #base #r, v_encrypt_##base##_##r,                                   \
 972     { &type_hex, &type_hex, &type_hex, &type_ulong,                     \
 973       &type_hex, &type_hex, 0 } },
 974 #define DEFTAB(r)                                                       \
 975   { "chacha" #r "-core", v_core_##r,                                    \
 976     { &type_int, &type_hex, &type_hex, 0 } },                           \
 977   DEFxTAB(chacha, r)
 978 #define DEFXTAB(r) DEFxTAB(xchacha, r)
 979 CHACHA_VARS(DEFTAB)
 980 CHACHA_VARS(DEFXTAB)
 981   { 0, 0, { 0 } }
 982 };
 983
 984 int main(int argc, char *argv[])
 985 {
 986   test_run(argc, argv, defs, SRCDIR"/t/chacha");
 987   return (0);
 988 }
 989
 990 #endif
 991
 992 /*----- That's all, folks -------------------------------------------------*/