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