umac.c

   1 /* $OpenBSD: umac.c,v 1.3 2008/05/12 20:52:20 pvalchev Exp $ */
   2 /* -----------------------------------------------------------------------
   3  *
   4  * umac.c -- C Implementation UMAC Message Authentication
   5  *
   6  * Version 0.93b of rfc4418.txt -- 2006 July 18
   7  *
   8  * For a full description of UMAC message authentication see the UMAC
   9  * world-wide-web page at http://www.cs.ucdavis.edu/~rogaway/umac
  10  * Please report bugs and suggestions to the UMAC webpage.
  11  *
  12  * Copyright (c) 1999-2006 Ted Krovetz
  13  *
  14  * Permission to use, copy, modify, and distribute this software and
  15  * its documentation for any purpose and with or without fee, is hereby
  16  * granted provided that the above copyright notice appears in all copies
  17  * and in supporting documentation, and that the name of the copyright
  18  * holder not be used in advertising or publicity pertaining to
  19  * distribution of the software without specific, written prior permission.
  20  *
  21  * Comments should be directed to Ted Krovetz (tdk@acm.org)
  22  *
  23  * ---------------------------------------------------------------------- */
  24
  25  /* ////////////////////// IMPORTANT NOTES /////////////////////////////////
  26   *
  27   * 1) This version does not work properly on messages larger than 16MB
  28   *
  29   * 2) If you set the switch to use SSE2, then all data must be 16-byte
  30   *    aligned
  31   *
  32   * 3) When calling the function umac(), it is assumed that msg is in
  33   * a writable buffer of length divisible by 32 bytes. The message itself
  34   * does not have to fill the entire buffer, but bytes beyond msg may be
  35   * zeroed.
  36   *
  37   * 4) Three free AES implementations are supported by this implementation of
  38   * UMAC. Paulo Barreto's version is in the public domain and can be found
  39   * at http://www.esat.kuleuven.ac.be/~rijmen/rijndael/ (search for
  40   * "Barreto"). The only two files needed are rijndael-alg-fst.c and
  41   * rijndael-alg-fst.h. Brian Gladman's version is distributed with the GNU
  42   * Public lisence at http://fp.gladman.plus.com/AES/index.htm. It
  43   * includes a fast IA-32 assembly version. The OpenSSL crypo library is
  44   * the third.
  45   *
  46   * 5) With FORCE_C_ONLY flags set to 0, incorrect results are sometimes
  47   * produced under gcc with optimizations set -O3 or higher. Dunno why.
  48   *
  49   /////////////////////////////////////////////////////////////////////// */
  50
  51 /* ---------------------------------------------------------------------- */
  52 /* --- User Switches ---------------------------------------------------- */
  53 /* ---------------------------------------------------------------------- */
  54
  55 #define UMAC_OUTPUT_LEN     8  /* Alowable: 4, 8, 12, 16                  */
  56 /* #define FORCE_C_ONLY        1  ANSI C and 64-bit integers req'd        */
  57 /* #define AES_IMPLEMENTAION   1  1 = OpenSSL, 2 = Barreto, 3 = Gladman   */
  58 /* #define SSE2                0  Is SSE2 is available?                   */
  59 /* #define RUN_TESTS           0  Run basic correctness/speed tests       */
  60 /* #define UMAC_AE_SUPPORT     0  Enable auhthenticated encrytion         */
  61
  62 /* ---------------------------------------------------------------------- */
  63 /* -- Global Includes --------------------------------------------------- */
  64 /* ---------------------------------------------------------------------- */
  65
  66 #include "includes.h"
  67 #include <sys/types.h>
  68
  69 #include "xmalloc.h"
  70 #include "umac.h"
  71 #include <string.h>
  72 #include <stdlib.h>
  73 #include <stddef.h>
  74
  75 /* ---------------------------------------------------------------------- */
  76 /* --- Primitive Data Types ---                                           */
  77 /* ---------------------------------------------------------------------- */
  78
  79 /* The following assumptions may need change on your system */
  80 typedef u_int8_t        UINT8;  /* 1 byte   */
  81 typedef u_int16_t       UINT16; /* 2 byte   */
  82 typedef u_int32_t       UINT32; /* 4 byte   */
  83 typedef u_int64_t       UINT64; /* 8 bytes  */
  84 typedef unsigned int    UWORD;  /* Register */
  85
  86 /* ---------------------------------------------------------------------- */
  87 /* --- Constants -------------------------------------------------------- */
  88 /* ---------------------------------------------------------------------- */
  89
  90 #define UMAC_KEY_LEN           16  /* UMAC takes 16 bytes of external key */
  91
  92 /* Message "words" are read from memory in an endian-specific manner.     */
  93 /* For this implementation to behave correctly, __LITTLE_ENDIAN__ must    */
  94 /* be set true if the host computer is little-endian.                     */
  95
  96 #if BYTE_ORDER == LITTLE_ENDIAN
  97 #define __LITTLE_ENDIAN__ 1
  98 #else
  99 #define __LITTLE_ENDIAN__ 0
 100 #endif
 101
 102 /* ---------------------------------------------------------------------- */
 103 /* ---------------------------------------------------------------------- */
 104 /* ----- Architecture Specific ------------------------------------------ */
 105 /* ---------------------------------------------------------------------- */
 106 /* ---------------------------------------------------------------------- */
 107
 108
 109 /* ---------------------------------------------------------------------- */
 110 /* ---------------------------------------------------------------------- */
 111 /* ----- Primitive Routines --------------------------------------------- */
 112 /* ---------------------------------------------------------------------- */
 113 /* ---------------------------------------------------------------------- */
 114
 115
 116 /* ---------------------------------------------------------------------- */
 117 /* --- 32-bit by 32-bit to 64-bit Multiplication ------------------------ */
 118 /* ---------------------------------------------------------------------- */
 119
 120 #define MUL64(a,b) ((UINT64)((UINT64)(UINT32)(a) * (UINT64)(UINT32)(b)))
 121
 122 /* ---------------------------------------------------------------------- */
 123 /* --- Endian Conversion --- Forcing assembly on some platforms           */
 124 /* ---------------------------------------------------------------------- */
 125
 126 #if HAVE_SWAP32
 127 #define LOAD_UINT32_REVERSED(p)         (swap32(*(UINT32 *)(p)))
 128 #define STORE_UINT32_REVERSED(p,v)      (*(UINT32 *)(p) = swap32(v))
 129 #else /* HAVE_SWAP32 */
 130
 131 static UINT32 LOAD_UINT32_REVERSED(void *ptr)
 132 {
 133     UINT32 temp = *(UINT32 *)ptr;
 134     temp = (temp >> 24) | ((temp & 0x00FF0000) >> 8 )
 135          | ((temp & 0x0000FF00) << 8 ) | (temp << 24);
 136     return (UINT32)temp;
 137 }
 138
 139 static void STORE_UINT32_REVERSED(void *ptr, UINT32 x)
 140 {
 141     UINT32 i = (UINT32)x;
 142     *(UINT32 *)ptr = (i >> 24) | ((i & 0x00FF0000) >> 8 )
 143                    | ((i & 0x0000FF00) << 8 ) | (i << 24);
 144 }
 145 #endif /* HAVE_SWAP32 */
 146
 147 /* The following definitions use the above reversal-primitives to do the right
 148  * thing on endian specific load and stores.
 149  */
 150
 151 #if (__LITTLE_ENDIAN__)
 152 #define LOAD_UINT32_LITTLE(ptr)     (*(UINT32 *)(ptr))
 153 #define STORE_UINT32_BIG(ptr,x)     STORE_UINT32_REVERSED(ptr,x)
 154 #else
 155 #define LOAD_UINT32_LITTLE(ptr)     LOAD_UINT32_REVERSED(ptr)
 156 #define STORE_UINT32_BIG(ptr,x)     (*(UINT32 *)(ptr) = (UINT32)(x))
 157 #endif
 158
 159 /* ---------------------------------------------------------------------- */
 160 /* ---------------------------------------------------------------------- */
 161 /* ----- Begin KDF & PDF Section ---------------------------------------- */
 162 /* ---------------------------------------------------------------------- */
 163 /* ---------------------------------------------------------------------- */
 164
 165 /* UMAC uses AES with 16 byte block and key lengths */
 166 #define AES_BLOCK_LEN  16
 167
 168 /* OpenSSL's AES */
 169 #include "openbsd-compat/openssl-compat.h"
 170 #ifndef USE_BUILTIN_RIJNDAEL
 171 # include <openssl/aes.h>
 172 #endif
 173 typedef AES_KEY aes_int_key[1];
 174 #define aes_encryption(in,out,int_key)                  \
 175   AES_encrypt((u_char *)(in),(u_char *)(out),(AES_KEY *)int_key)
 176 #define aes_key_setup(key,int_key)                      \
 177   AES_set_encrypt_key((u_char *)(key),UMAC_KEY_LEN*8,int_key)
 178
 179 /* The user-supplied UMAC key is stretched using AES in a counter
 180  * mode to supply all random bits needed by UMAC. The kdf function takes
 181  * an AES internal key representation 'key' and writes a stream of
 182  * 'nbytes' bytes to the memory pointed at by 'buffer_ptr'. Each distinct
 183  * 'ndx' causes a distinct byte stream.
 184  */
 185 static void kdf(void *buffer_ptr, aes_int_key key, UINT8 ndx, int nbytes)
 186 {
 187     UINT8 in_buf[AES_BLOCK_LEN] = {0};
 188     UINT8 out_buf[AES_BLOCK_LEN];
 189     UINT8 *dst_buf = (UINT8 *)buffer_ptr;
 190     int i;
 191
 192     /* Setup the initial value */
 193     in_buf[AES_BLOCK_LEN-9] = ndx;
 194     in_buf[AES_BLOCK_LEN-1] = i = 1;
 195
 196     while (nbytes >= AES_BLOCK_LEN) {
 197         aes_encryption(in_buf, out_buf, key);
 198         memcpy(dst_buf,out_buf,AES_BLOCK_LEN);
 199         in_buf[AES_BLOCK_LEN-1] = ++i;
 200         nbytes -= AES_BLOCK_LEN;
 201         dst_buf += AES_BLOCK_LEN;
 202     }
 203     if (nbytes) {
 204         aes_encryption(in_buf, out_buf, key);
 205         memcpy(dst_buf,out_buf,nbytes);
 206     }
 207 }
 208
 209 /* The final UHASH result is XOR'd with the output of a pseudorandom
 210  * function. Here, we use AES to generate random output and
 211  * xor the appropriate bytes depending on the last bits of nonce.
 212  * This scheme is optimized for sequential, increasing big-endian nonces.
 213  */
 214
 215 typedef struct {
 216     UINT8 cache[AES_BLOCK_LEN];  /* Previous AES output is saved      */
 217     UINT8 nonce[AES_BLOCK_LEN];  /* The AES input making above cache  */
 218     aes_int_key prf_key;         /* Expanded AES key for PDF          */
 219 } pdf_ctx;
 220
 221 static void pdf_init(pdf_ctx *pc, aes_int_key prf_key)
 222 {
 223     UINT8 buf[UMAC_KEY_LEN];
 224
 225     kdf(buf, prf_key, 0, UMAC_KEY_LEN);
 226     aes_key_setup(buf, pc->prf_key);
 227
 228     /* Initialize pdf and cache */
 229     memset(pc->nonce, 0, sizeof(pc->nonce));
 230     aes_encryption(pc->nonce, pc->cache, pc->prf_key);
 231 }
 232
 233 static void pdf_gen_xor(pdf_ctx *pc, UINT8 nonce[8], UINT8 buf[8])
 234 {
 235     /* 'ndx' indicates that we'll be using the 0th or 1st eight bytes
 236      * of the AES output. If last time around we returned the ndx-1st
 237      * element, then we may have the result in the cache already.
 238      */
 239
 240 #if (UMAC_OUTPUT_LEN == 4)
 241 #define LOW_BIT_MASK 3
 242 #elif (UMAC_OUTPUT_LEN == 8)
 243 #define LOW_BIT_MASK 1
 244 #elif (UMAC_OUTPUT_LEN > 8)
 245 #define LOW_BIT_MASK 0
 246 #endif
 247
 248     UINT8 tmp_nonce_lo[4];
 249 #if LOW_BIT_MASK != 0
 250     int ndx = nonce[7] & LOW_BIT_MASK;
 251 #endif
 252     *(UINT32 *)tmp_nonce_lo = ((UINT32 *)nonce)[1];
 253     tmp_nonce_lo[3] &= ~LOW_BIT_MASK; /* zero last bit */
 254
 255     if ( (((UINT32 *)tmp_nonce_lo)[0] != ((UINT32 *)pc->nonce)[1]) ||
 256          (((UINT32 *)nonce)[0] != ((UINT32 *)pc->nonce)[0]) )
 257     {
 258         ((UINT32 *)pc->nonce)[0] = ((UINT32 *)nonce)[0];
 259         ((UINT32 *)pc->nonce)[1] = ((UINT32 *)tmp_nonce_lo)[0];
 260         aes_encryption(pc->nonce, pc->cache, pc->prf_key);
 261     }
 262
 263 #if (UMAC_OUTPUT_LEN == 4)
 264     *((UINT32 *)buf) ^= ((UINT32 *)pc->cache)[ndx];
 265 #elif (UMAC_OUTPUT_LEN == 8)
 266     *((UINT64 *)buf) ^= ((UINT64 *)pc->cache)[ndx];
 267 #elif (UMAC_OUTPUT_LEN == 12)
 268     ((UINT64 *)buf)[0] ^= ((UINT64 *)pc->cache)[0];
 269     ((UINT32 *)buf)[2] ^= ((UINT32 *)pc->cache)[2];
 270 #elif (UMAC_OUTPUT_LEN == 16)
 271     ((UINT64 *)buf)[0] ^= ((UINT64 *)pc->cache)[0];
 272     ((UINT64 *)buf)[1] ^= ((UINT64 *)pc->cache)[1];
 273 #endif
 274 }
 275
 276 /* ---------------------------------------------------------------------- */
 277 /* ---------------------------------------------------------------------- */
 278 /* ----- Begin NH Hash Section ------------------------------------------ */
 279 /* ---------------------------------------------------------------------- */
 280 /* ---------------------------------------------------------------------- */
 281
 282 /* The NH-based hash functions used in UMAC are described in the UMAC paper
 283  * and specification, both of which can be found at the UMAC website.
 284  * The interface to this implementation has two
 285  * versions, one expects the entire message being hashed to be passed
 286  * in a single buffer and returns the hash result immediately. The second
 287  * allows the message to be passed in a sequence of buffers. In the
 288  * muliple-buffer interface, the client calls the routine nh_update() as
 289  * many times as necessary. When there is no more data to be fed to the
 290  * hash, the client calls nh_final() which calculates the hash output.
 291  * Before beginning another hash calculation the nh_reset() routine
 292  * must be called. The single-buffer routine, nh(), is equivalent to
 293  * the sequence of calls nh_update() and nh_final(); however it is
 294  * optimized and should be prefered whenever the multiple-buffer interface
 295  * is not necessary. When using either interface, it is the client's
 296  * responsability to pass no more than L1_KEY_LEN bytes per hash result.
 297  *
 298  * The routine nh_init() initializes the nh_ctx data structure and
 299  * must be called once, before any other PDF routine.
 300  */
 301
 302  /* The "nh_aux" routines do the actual NH hashing work. They
 303   * expect buffers to be multiples of L1_PAD_BOUNDARY. These routines
 304   * produce output for all STREAMS NH iterations in one call,
 305   * allowing the parallel implementation of the streams.
 306   */
 307
 308 #define STREAMS (UMAC_OUTPUT_LEN / 4) /* Number of times hash is applied  */
 309 #define L1_KEY_LEN         1024     /* Internal key bytes                 */
 310 #define L1_KEY_SHIFT         16     /* Toeplitz key shift between streams */
 311 #define L1_PAD_BOUNDARY      32     /* pad message to boundary multiple   */
 312 #define ALLOC_BOUNDARY       16     /* Keep buffers aligned to this       */
 313 #define HASH_BUF_BYTES       64     /* nh_aux_hb buffer multiple          */
 314
 315 typedef struct {
 316     UINT8  nh_key [L1_KEY_LEN + L1_KEY_SHIFT * (STREAMS - 1)]; /* NH Key */
 317     UINT8  data   [HASH_BUF_BYTES];    /* Incomming data buffer           */
 318     int next_data_empty;    /* Bookeeping variable for data buffer.       */
 319     int bytes_hashed;        /* Bytes (out of L1_KEY_LEN) incorperated.   */
 320     UINT64 state[STREAMS];               /* on-line state     */
 321 } nh_ctx;
 322
 323
 324 #if (UMAC_OUTPUT_LEN == 4)
 325
 326 static void nh_aux(void *kp, void *dp, void *hp, UINT32 dlen)
 327 /* NH hashing primitive. Previous (partial) hash result is loaded and
 328 * then stored via hp pointer. The length of the data pointed at by "dp",
 329 * "dlen", is guaranteed to be divisible by L1_PAD_BOUNDARY (32).  Key
 330 * is expected to be endian compensated in memory at key setup.
 331 */
 332 {
 333     UINT64 h;
 334     UWORD c = dlen / 32;
 335     UINT32 *k = (UINT32 *)kp;
 336     UINT32 *d = (UINT32 *)dp;
 337     UINT32 d0,d1,d2,d3,d4,d5,d6,d7;
 338     UINT32 k0,k1,k2,k3,k4,k5,k6,k7;
 339
 340     h = *((UINT64 *)hp);
 341     do {
 342         d0 = LOAD_UINT32_LITTLE(d+0); d1 = LOAD_UINT32_LITTLE(d+1);
 343         d2 = LOAD_UINT32_LITTLE(d+2); d3 = LOAD_UINT32_LITTLE(d+3);
 344         d4 = LOAD_UINT32_LITTLE(d+4); d5 = LOAD_UINT32_LITTLE(d+5);
 345         d6 = LOAD_UINT32_LITTLE(d+6); d7 = LOAD_UINT32_LITTLE(d+7);
 346         k0 = *(k+0); k1 = *(k+1); k2 = *(k+2); k3 = *(k+3);
 347         k4 = *(k+4); k5 = *(k+5); k6 = *(k+6); k7 = *(k+7);
 348         h += MUL64((k0 + d0), (k4 + d4));
 349         h += MUL64((k1 + d1), (k5 + d5));
 350         h += MUL64((k2 + d2), (k6 + d6));
 351         h += MUL64((k3 + d3), (k7 + d7));
 352
 353         d += 8;
 354         k += 8;
 355     } while (--c);
 356   *((UINT64 *)hp) = h;
 357 }
 358
 359 #elif (UMAC_OUTPUT_LEN == 8)
 360
 361 static void nh_aux(void *kp, void *dp, void *hp, UINT32 dlen)
 362 /* Same as previous nh_aux, but two streams are handled in one pass,
 363  * reading and writing 16 bytes of hash-state per call.
 364  */
 365 {
 366   UINT64 h1,h2;
 367   UWORD c = dlen / 32;
 368   UINT32 *k = (UINT32 *)kp;
 369   UINT32 *d = (UINT32 *)dp;
 370   UINT32 d0,d1,d2,d3,d4,d5,d6,d7;
 371   UINT32 k0,k1,k2,k3,k4,k5,k6,k7,
 372         k8,k9,k10,k11;
 373
 374   h1 = *((UINT64 *)hp);
 375   h2 = *((UINT64 *)hp + 1);
 376   k0 = *(k+0); k1 = *(k+1); k2 = *(k+2); k3 = *(k+3);
 377   do {
 378     d0 = LOAD_UINT32_LITTLE(d+0); d1 = LOAD_UINT32_LITTLE(d+1);
 379     d2 = LOAD_UINT32_LITTLE(d+2); d3 = LOAD_UINT32_LITTLE(d+3);
 380     d4 = LOAD_UINT32_LITTLE(d+4); d5 = LOAD_UINT32_LITTLE(d+5);
 381     d6 = LOAD_UINT32_LITTLE(d+6); d7 = LOAD_UINT32_LITTLE(d+7);
 382     k4 = *(k+4); k5 = *(k+5); k6 = *(k+6); k7 = *(k+7);
 383     k8 = *(k+8); k9 = *(k+9); k10 = *(k+10); k11 = *(k+11);
 384
 385     h1 += MUL64((k0 + d0), (k4 + d4));
 386     h2 += MUL64((k4 + d0), (k8 + d4));
 387
 388     h1 += MUL64((k1 + d1), (k5 + d5));
 389     h2 += MUL64((k5 + d1), (k9 + d5));
 390
 391     h1 += MUL64((k2 + d2), (k6 + d6));
 392     h2 += MUL64((k6 + d2), (k10 + d6));
 393
 394     h1 += MUL64((k3 + d3), (k7 + d7));
 395     h2 += MUL64((k7 + d3), (k11 + d7));
 396
 397     k0 = k8; k1 = k9; k2 = k10; k3 = k11;
 398
 399     d += 8;
 400     k += 8;
 401   } while (--c);
 402   ((UINT64 *)hp)[0] = h1;
 403   ((UINT64 *)hp)[1] = h2;
 404 }
 405
 406 #elif (UMAC_OUTPUT_LEN == 12)
 407
 408 static void nh_aux(void *kp, void *dp, void *hp, UINT32 dlen)
 409 /* Same as previous nh_aux, but two streams are handled in one pass,
 410  * reading and writing 24 bytes of hash-state per call.
 411 */
 412 {
 413     UINT64 h1,h2,h3;
 414     UWORD c = dlen / 32;
 415     UINT32 *k = (UINT32 *)kp;
 416     UINT32 *d = (UINT32 *)dp;
 417     UINT32 d0,d1,d2,d3,d4,d5,d6,d7;
 418     UINT32 k0,k1,k2,k3,k4,k5,k6,k7,
 419         k8,k9,k10,k11,k12,k13,k14,k15;
 420
 421     h1 = *((UINT64 *)hp);
 422     h2 = *((UINT64 *)hp + 1);
 423     h3 = *((UINT64 *)hp + 2);
 424     k0 = *(k+0); k1 = *(k+1); k2 = *(k+2); k3 = *(k+3);
 425     k4 = *(k+4); k5 = *(k+5); k6 = *(k+6); k7 = *(k+7);
 426     do {
 427         d0 = LOAD_UINT32_LITTLE(d+0); d1 = LOAD_UINT32_LITTLE(d+1);
 428         d2 = LOAD_UINT32_LITTLE(d+2); d3 = LOAD_UINT32_LITTLE(d+3);
 429         d4 = LOAD_UINT32_LITTLE(d+4); d5 = LOAD_UINT32_LITTLE(d+5);
 430         d6 = LOAD_UINT32_LITTLE(d+6); d7 = LOAD_UINT32_LITTLE(d+7);
 431         k8 = *(k+8); k9 = *(k+9); k10 = *(k+10); k11 = *(k+11);
 432         k12 = *(k+12); k13 = *(k+13); k14 = *(k+14); k15 = *(k+15);
 433
 434         h1 += MUL64((k0 + d0), (k4 + d4));
 435         h2 += MUL64((k4 + d0), (k8 + d4));
 436         h3 += MUL64((k8 + d0), (k12 + d4));
 437
 438         h1 += MUL64((k1 + d1), (k5 + d5));
 439         h2 += MUL64((k5 + d1), (k9 + d5));
 440         h3 += MUL64((k9 + d1), (k13 + d5));
 441
 442         h1 += MUL64((k2 + d2), (k6 + d6));
 443         h2 += MUL64((k6 + d2), (k10 + d6));
 444         h3 += MUL64((k10 + d2), (k14 + d6));
 445
 446         h1 += MUL64((k3 + d3), (k7 + d7));
 447         h2 += MUL64((k7 + d3), (k11 + d7));
 448         h3 += MUL64((k11 + d3), (k15 + d7));
 449
 450         k0 = k8; k1 = k9; k2 = k10; k3 = k11;
 451         k4 = k12; k5 = k13; k6 = k14; k7 = k15;
 452
 453         d += 8;
 454         k += 8;
 455     } while (--c);
 456     ((UINT64 *)hp)[0] = h1;
 457     ((UINT64 *)hp)[1] = h2;
 458     ((UINT64 *)hp)[2] = h3;
 459 }
 460
 461 #elif (UMAC_OUTPUT_LEN == 16)
 462
 463 static void nh_aux(void *kp, void *dp, void *hp, UINT32 dlen)
 464 /* Same as previous nh_aux, but two streams are handled in one pass,
 465  * reading and writing 24 bytes of hash-state per call.
 466 */
 467 {
 468     UINT64 h1,h2,h3,h4;
 469     UWORD c = dlen / 32;
 470     UINT32 *k = (UINT32 *)kp;
 471     UINT32 *d = (UINT32 *)dp;
 472     UINT32 d0,d1,d2,d3,d4,d5,d6,d7;
 473     UINT32 k0,k1,k2,k3,k4,k5,k6,k7,
 474         k8,k9,k10,k11,k12,k13,k14,k15,
 475         k16,k17,k18,k19;
 476
 477     h1 = *((UINT64 *)hp);
 478     h2 = *((UINT64 *)hp + 1);
 479     h3 = *((UINT64 *)hp + 2);
 480     h4 = *((UINT64 *)hp + 3);
 481     k0 = *(k+0); k1 = *(k+1); k2 = *(k+2); k3 = *(k+3);
 482     k4 = *(k+4); k5 = *(k+5); k6 = *(k+6); k7 = *(k+7);
 483     do {
 484         d0 = LOAD_UINT32_LITTLE(d+0); d1 = LOAD_UINT32_LITTLE(d+1);
 485         d2 = LOAD_UINT32_LITTLE(d+2); d3 = LOAD_UINT32_LITTLE(d+3);
 486         d4 = LOAD_UINT32_LITTLE(d+4); d5 = LOAD_UINT32_LITTLE(d+5);
 487         d6 = LOAD_UINT32_LITTLE(d+6); d7 = LOAD_UINT32_LITTLE(d+7);
 488         k8 = *(k+8); k9 = *(k+9); k10 = *(k+10); k11 = *(k+11);
 489         k12 = *(k+12); k13 = *(k+13); k14 = *(k+14); k15 = *(k+15);
 490         k16 = *(k+16); k17 = *(k+17); k18 = *(k+18); k19 = *(k+19);
 491
 492         h1 += MUL64((k0 + d0), (k4 + d4));
 493         h2 += MUL64((k4 + d0), (k8 + d4));
 494         h3 += MUL64((k8 + d0), (k12 + d4));
 495         h4 += MUL64((k12 + d0), (k16 + d4));
 496
 497         h1 += MUL64((k1 + d1), (k5 + d5));
 498         h2 += MUL64((k5 + d1), (k9 + d5));
 499         h3 += MUL64((k9 + d1), (k13 + d5));
 500         h4 += MUL64((k13 + d1), (k17 + d5));
 501
 502         h1 += MUL64((k2 + d2), (k6 + d6));
 503         h2 += MUL64((k6 + d2), (k10 + d6));
 504         h3 += MUL64((k10 + d2), (k14 + d6));
 505         h4 += MUL64((k14 + d2), (k18 + d6));
 506
 507         h1 += MUL64((k3 + d3), (k7 + d7));
 508         h2 += MUL64((k7 + d3), (k11 + d7));
 509         h3 += MUL64((k11 + d3), (k15 + d7));
 510         h4 += MUL64((k15 + d3), (k19 + d7));
 511
 512         k0 = k8; k1 = k9; k2 = k10; k3 = k11;
 513         k4 = k12; k5 = k13; k6 = k14; k7 = k15;
 514         k8 = k16; k9 = k17; k10 = k18; k11 = k19;
 515
 516         d += 8;
 517         k += 8;
 518     } while (--c);
 519     ((UINT64 *)hp)[0] = h1;
 520     ((UINT64 *)hp)[1] = h2;
 521     ((UINT64 *)hp)[2] = h3;
 522     ((UINT64 *)hp)[3] = h4;
 523 }
 524
 525 /* ---------------------------------------------------------------------- */
 526 #endif  /* UMAC_OUTPUT_LENGTH */
 527 /* ---------------------------------------------------------------------- */
 528
 529
 530 /* ---------------------------------------------------------------------- */
 531
 532 static void nh_transform(nh_ctx *hc, UINT8 *buf, UINT32 nbytes)
 533 /* This function is a wrapper for the primitive NH hash functions. It takes
 534  * as argument "hc" the current hash context and a buffer which must be a
 535  * multiple of L1_PAD_BOUNDARY. The key passed to nh_aux is offset
 536  * appropriately according to how much message has been hashed already.
 537  */
 538 {
 539     UINT8 *key;
 540
 541     key = hc->nh_key + hc->bytes_hashed;
 542     nh_aux(key, buf, hc->state, nbytes);
 543 }
 544
 545 /* ---------------------------------------------------------------------- */
 546
 547 static void endian_convert(void *buf, UWORD bpw, UINT32 num_bytes)
 548 /* We endian convert the keys on little-endian computers to               */
 549 /* compensate for the lack of big-endian memory reads during hashing.     */
 550 {
 551     UWORD iters = num_bytes / bpw;
 552     if (bpw == 4) {
 553         UINT32 *p = (UINT32 *)buf;
 554         do {
 555             *p = LOAD_UINT32_REVERSED(p);
 556             p++;
 557         } while (--iters);
 558     } else if (bpw == 8) {
 559         UINT32 *p = (UINT32 *)buf;
 560         UINT32 t;
 561         do {
 562             t = LOAD_UINT32_REVERSED(p+1);
 563             p[1] = LOAD_UINT32_REVERSED(p);
 564             p[0] = t;
 565             p += 2;
 566         } while (--iters);
 567     }
 568 }
 569 #if (__LITTLE_ENDIAN__)
 570 #define endian_convert_if_le(x,y,z) endian_convert((x),(y),(z))
 571 #else
 572 #define endian_convert_if_le(x,y,z) do{}while(0)  /* Do nothing */
 573 #endif
 574
 575 /* ---------------------------------------------------------------------- */
 576
 577 static void nh_reset(nh_ctx *hc)
 578 /* Reset nh_ctx to ready for hashing of new data */
 579 {
 580     hc->bytes_hashed = 0;
 581     hc->next_data_empty = 0;
 582     hc->state[0] = 0;
 583 #if (UMAC_OUTPUT_LEN >= 8)
 584     hc->state[1] = 0;
 585 #endif
 586 #if (UMAC_OUTPUT_LEN >= 12)
 587     hc->state[2] = 0;
 588 #endif
 589 #if (UMAC_OUTPUT_LEN == 16)
 590     hc->state[3] = 0;
 591 #endif
 592
 593 }
 594
 595 /* ---------------------------------------------------------------------- */
 596
 597 static void nh_init(nh_ctx *hc, aes_int_key prf_key)
 598 /* Generate nh_key, endian convert and reset to be ready for hashing.   */
 599 {
 600     kdf(hc->nh_key, prf_key, 1, sizeof(hc->nh_key));
 601     endian_convert_if_le(hc->nh_key, 4, sizeof(hc->nh_key));
 602     nh_reset(hc);
 603 }
 604
 605 /* ---------------------------------------------------------------------- */
 606
 607 static void nh_update(nh_ctx *hc, UINT8 *buf, UINT32 nbytes)
 608 /* Incorporate nbytes of data into a nh_ctx, buffer whatever is not an    */
 609 /* even multiple of HASH_BUF_BYTES.                                       */
 610 {
 611     UINT32 i,j;
 612
 613     j = hc->next_data_empty;
 614     if ((j + nbytes) >= HASH_BUF_BYTES) {
 615         if (j) {
 616             i = HASH_BUF_BYTES - j;
 617             memcpy(hc->data+j, buf, i);
 618             nh_transform(hc,hc->data,HASH_BUF_BYTES);
 619             nbytes -= i;
 620             buf += i;
 621             hc->bytes_hashed += HASH_BUF_BYTES;
 622         }
 623         if (nbytes >= HASH_BUF_BYTES) {
 624             i = nbytes & ~(HASH_BUF_BYTES - 1);
 625             nh_transform(hc, buf, i);
 626             nbytes -= i;
 627             buf += i;
 628             hc->bytes_hashed += i;
 629         }
 630         j = 0;
 631     }
 632     memcpy(hc->data + j, buf, nbytes);
 633     hc->next_data_empty = j + nbytes;
 634 }
 635
 636 /* ---------------------------------------------------------------------- */
 637
 638 static void zero_pad(UINT8 *p, int nbytes)
 639 {
 640 /* Write "nbytes" of zeroes, beginning at "p" */
 641     if (nbytes >= (int)sizeof(UWORD)) {
 642         while ((ptrdiff_t)p % sizeof(UWORD)) {
 643             *p = 0;
 644             nbytes--;
 645             p++;
 646         }
 647         while (nbytes >= (int)sizeof(UWORD)) {
 648             *(UWORD *)p = 0;
 649             nbytes -= sizeof(UWORD);
 650             p += sizeof(UWORD);
 651         }
 652     }
 653     while (nbytes) {
 654         *p = 0;
 655         nbytes--;
 656         p++;
 657     }
 658 }
 659
 660 /* ---------------------------------------------------------------------- */
 661
 662 static void nh_final(nh_ctx *hc, UINT8 *result)
 663 /* After passing some number of data buffers to nh_update() for integration
 664  * into an NH context, nh_final is called to produce a hash result. If any
 665  * bytes are in the buffer hc->data, incorporate them into the
 666  * NH context. Finally, add into the NH accumulation "state" the total number
 667  * of bits hashed. The resulting numbers are written to the buffer "result".
 668  * If nh_update was never called, L1_PAD_BOUNDARY zeroes are incorporated.
 669  */
 670 {
 671     int nh_len, nbits;
 672
 673     if (hc->next_data_empty != 0) {
 674         nh_len = ((hc->next_data_empty + (L1_PAD_BOUNDARY - 1)) &
 675                                                 ~(L1_PAD_BOUNDARY - 1));
 676         zero_pad(hc->data + hc->next_data_empty,
 677                                           nh_len - hc->next_data_empty);
 678         nh_transform(hc, hc->data, nh_len);
 679         hc->bytes_hashed += hc->next_data_empty;
 680     } else if (hc->bytes_hashed == 0) {
 681         nh_len = L1_PAD_BOUNDARY;
 682         zero_pad(hc->data, L1_PAD_BOUNDARY);
 683         nh_transform(hc, hc->data, nh_len);
 684     }
 685
 686     nbits = (hc->bytes_hashed << 3);
 687     ((UINT64 *)result)[0] = ((UINT64 *)hc->state)[0] + nbits;
 688 #if (UMAC_OUTPUT_LEN >= 8)
 689     ((UINT64 *)result)[1] = ((UINT64 *)hc->state)[1] + nbits;
 690 #endif
 691 #if (UMAC_OUTPUT_LEN >= 12)
 692     ((UINT64 *)result)[2] = ((UINT64 *)hc->state)[2] + nbits;
 693 #endif
 694 #if (UMAC_OUTPUT_LEN == 16)
 695     ((UINT64 *)result)[3] = ((UINT64 *)hc->state)[3] + nbits;
 696 #endif
 697     nh_reset(hc);
 698 }
 699
 700 /* ---------------------------------------------------------------------- */
 701
 702 static void nh(nh_ctx *hc, UINT8 *buf, UINT32 padded_len,
 703                UINT32 unpadded_len, UINT8 *result)
 704 /* All-in-one nh_update() and nh_final() equivalent.
 705  * Assumes that padded_len is divisible by L1_PAD_BOUNDARY and result is
 706  * well aligned
 707  */
 708 {
 709     UINT32 nbits;
 710
 711     /* Initialize the hash state */
 712     nbits = (unpadded_len << 3);
 713
 714     ((UINT64 *)result)[0] = nbits;
 715 #if (UMAC_OUTPUT_LEN >= 8)
 716     ((UINT64 *)result)[1] = nbits;
 717 #endif
 718 #if (UMAC_OUTPUT_LEN >= 12)
 719     ((UINT64 *)result)[2] = nbits;
 720 #endif
 721 #if (UMAC_OUTPUT_LEN == 16)
 722     ((UINT64 *)result)[3] = nbits;
 723 #endif
 724
 725     nh_aux(hc->nh_key, buf, result, padded_len);
 726 }
 727
 728 /* ---------------------------------------------------------------------- */
 729 /* ---------------------------------------------------------------------- */
 730 /* ----- Begin UHASH Section -------------------------------------------- */
 731 /* ---------------------------------------------------------------------- */
 732 /* ---------------------------------------------------------------------- */
 733
 734 /* UHASH is a multi-layered algorithm. Data presented to UHASH is first
 735  * hashed by NH. The NH output is then hashed by a polynomial-hash layer
 736  * unless the initial data to be hashed is short. After the polynomial-
 737  * layer, an inner-product hash is used to produce the final UHASH output.
 738  *
 739  * UHASH provides two interfaces, one all-at-once and another where data
 740  * buffers are presented sequentially. In the sequential interface, the
 741  * UHASH client calls the routine uhash_update() as many times as necessary.
 742  * When there is no more data to be fed to UHASH, the client calls
 743  * uhash_final() which
 744  * calculates the UHASH output. Before beginning another UHASH calculation
 745  * the uhash_reset() routine must be called. The all-at-once UHASH routine,
 746  * uhash(), is equivalent to the sequence of calls uhash_update() and
 747  * uhash_final(); however it is optimized and should be
 748  * used whenever the sequential interface is not necessary.
 749  *
 750  * The routine uhash_init() initializes the uhash_ctx data structure and
 751  * must be called once, before any other UHASH routine.
 752  */
 753
 754 /* ---------------------------------------------------------------------- */
 755 /* ----- Constants and uhash_ctx ---------------------------------------- */
 756 /* ---------------------------------------------------------------------- */
 757
 758 /* ---------------------------------------------------------------------- */
 759 /* ----- Poly hash and Inner-Product hash Constants --------------------- */
 760 /* ---------------------------------------------------------------------- */
 761
 762 /* Primes and masks */
 763 #define p36    ((UINT64)0x0000000FFFFFFFFBull)              /* 2^36 -  5 */
 764 #define p64    ((UINT64)0xFFFFFFFFFFFFFFC5ull)              /* 2^64 - 59 */
 765 #define m36    ((UINT64)0x0000000FFFFFFFFFull)  /* The low 36 of 64 bits */
 766
 767
 768 /* ---------------------------------------------------------------------- */
 769
 770 typedef struct uhash_ctx {
 771     nh_ctx hash;                          /* Hash context for L1 NH hash  */
 772     UINT64 poly_key_8[STREAMS];           /* p64 poly keys                */
 773     UINT64 poly_accum[STREAMS];           /* poly hash result             */
 774     UINT64 ip_keys[STREAMS*4];            /* Inner-product keys           */
 775     UINT32 ip_trans[STREAMS];             /* Inner-product translation    */
 776     UINT32 msg_len;                       /* Total length of data passed  */
 777                                           /* to uhash */
 778 } uhash_ctx;
 779 typedef struct uhash_ctx *uhash_ctx_t;
 780
 781 /* ---------------------------------------------------------------------- */
 782
 783
 784 /* The polynomial hashes use Horner's rule to evaluate a polynomial one
 785  * word at a time. As described in the specification, poly32 and poly64
 786  * require keys from special domains. The following implementations exploit
 787  * the special domains to avoid overflow. The results are not guaranteed to
 788  * be within Z_p32 and Z_p64, but the Inner-Product hash implementation
 789  * patches any errant values.
 790  */
 791
 792 static UINT64 poly64(UINT64 cur, UINT64 key, UINT64 data)
 793 {
 794     UINT32 key_hi = (UINT32)(key >> 32),
 795            key_lo = (UINT32)key,
 796            cur_hi = (UINT32)(cur >> 32),
 797            cur_lo = (UINT32)cur,
 798            x_lo,
 799            x_hi;
 800     UINT64 X,T,res;
 801
 802     X =  MUL64(key_hi, cur_lo) + MUL64(cur_hi, key_lo);
 803     x_lo = (UINT32)X;
 804     x_hi = (UINT32)(X >> 32);
 805
 806     res = (MUL64(key_hi, cur_hi) + x_hi) * 59 + MUL64(key_lo, cur_lo);
 807
 808     T = ((UINT64)x_lo << 32);
 809     res += T;
 810     if (res < T)
 811         res += 59;
 812
 813     res += data;
 814     if (res < data)
 815         res += 59;
 816
 817     return res;
 818 }
 819
 820
 821 /* Although UMAC is specified to use a ramped polynomial hash scheme, this
 822  * implementation does not handle all ramp levels. Because we don't handle
 823  * the ramp up to p128 modulus in this implementation, we are limited to
 824  * 2^14 poly_hash() invocations per stream (for a total capacity of 2^24
 825  * bytes input to UMAC per tag, ie. 16MB).
 826  */
 827 static void poly_hash(uhash_ctx_t hc, UINT32 data_in[])
 828 {
 829     int i;
 830     UINT64 *data=(UINT64*)data_in;
 831
 832     for (i = 0; i < STREAMS; i++) {
 833         if ((UINT32)(data[i] >> 32) == 0xfffffffful) {
 834             hc->poly_accum[i] = poly64(hc->poly_accum[i],
 835                                        hc->poly_key_8[i], p64 - 1);
 836             hc->poly_accum[i] = poly64(hc->poly_accum[i],
 837                                        hc->poly_key_8[i], (data[i] - 59));
 838         } else {
 839             hc->poly_accum[i] = poly64(hc->poly_accum[i],
 840                                        hc->poly_key_8[i], data[i]);
 841         }
 842     }
 843 }
 844
 845
 846 /* ---------------------------------------------------------------------- */
 847
 848
 849 /* The final step in UHASH is an inner-product hash. The poly hash
 850  * produces a result not neccesarily WORD_LEN bytes long. The inner-
 851  * product hash breaks the polyhash output into 16-bit chunks and
 852  * multiplies each with a 36 bit key.
 853  */
 854
 855 static UINT64 ip_aux(UINT64 t, UINT64 *ipkp, UINT64 data)
 856 {
 857     t = t + ipkp[0] * (UINT64)(UINT16)(data >> 48);
 858     t = t + ipkp[1] * (UINT64)(UINT16)(data >> 32);
 859     t = t + ipkp[2] * (UINT64)(UINT16)(data >> 16);
 860     t = t + ipkp[3] * (UINT64)(UINT16)(data);
 861
 862     return t;
 863 }
 864
 865 static UINT32 ip_reduce_p36(UINT64 t)
 866 {
 867 /* Divisionless modular reduction */
 868     UINT64 ret;
 869
 870     ret = (t & m36) + 5 * (t >> 36);
 871     if (ret >= p36)
 872         ret -= p36;
 873
 874     /* return least significant 32 bits */
 875     return (UINT32)(ret);
 876 }
 877
 878
 879 /* If the data being hashed by UHASH is no longer than L1_KEY_LEN, then
 880  * the polyhash stage is skipped and ip_short is applied directly to the
 881  * NH output.
 882  */
 883 static void ip_short(uhash_ctx_t ahc, UINT8 *nh_res, u_char *res)
 884 {
 885     UINT64 t;
 886     UINT64 *nhp = (UINT64 *)nh_res;
 887
 888     t  = ip_aux(0,ahc->ip_keys, nhp[0]);
 889     STORE_UINT32_BIG((UINT32 *)res+0, ip_reduce_p36(t) ^ ahc->ip_trans[0]);
 890 #if (UMAC_OUTPUT_LEN >= 8)
 891     t  = ip_aux(0,ahc->ip_keys+4, nhp[1]);
 892     STORE_UINT32_BIG((UINT32 *)res+1, ip_reduce_p36(t) ^ ahc->ip_trans[1]);
 893 #endif
 894 #if (UMAC_OUTPUT_LEN >= 12)
 895     t  = ip_aux(0,ahc->ip_keys+8, nhp[2]);
 896     STORE_UINT32_BIG((UINT32 *)res+2, ip_reduce_p36(t) ^ ahc->ip_trans[2]);
 897 #endif
 898 #if (UMAC_OUTPUT_LEN == 16)
 899     t  = ip_aux(0,ahc->ip_keys+12, nhp[3]);
 900     STORE_UINT32_BIG((UINT32 *)res+3, ip_reduce_p36(t) ^ ahc->ip_trans[3]);
 901 #endif
 902 }
 903
 904 /* If the data being hashed by UHASH is longer than L1_KEY_LEN, then
 905  * the polyhash stage is not skipped and ip_long is applied to the
 906  * polyhash output.
 907  */
 908 static void ip_long(uhash_ctx_t ahc, u_char *res)
 909 {
 910     int i;
 911     UINT64 t;
 912
 913     for (i = 0; i < STREAMS; i++) {
 914         /* fix polyhash output not in Z_p64 */
 915         if (ahc->poly_accum[i] >= p64)
 916             ahc->poly_accum[i] -= p64;
 917         t  = ip_aux(0,ahc->ip_keys+(i*4), ahc->poly_accum[i]);
 918         STORE_UINT32_BIG((UINT32 *)res+i,
 919                          ip_reduce_p36(t) ^ ahc->ip_trans[i]);
 920     }
 921 }
 922
 923
 924 /* ---------------------------------------------------------------------- */
 925
 926 /* ---------------------------------------------------------------------- */
 927
 928 /* Reset uhash context for next hash session */
 929 static int uhash_reset(uhash_ctx_t pc)
 930 {
 931     nh_reset(&pc->hash);
 932     pc->msg_len = 0;
 933     pc->poly_accum[0] = 1;
 934 #if (UMAC_OUTPUT_LEN >= 8)
 935     pc->poly_accum[1] = 1;
 936 #endif
 937 #if (UMAC_OUTPUT_LEN >= 12)
 938     pc->poly_accum[2] = 1;
 939 #endif
 940 #if (UMAC_OUTPUT_LEN == 16)
 941     pc->poly_accum[3] = 1;
 942 #endif
 943     return 1;
 944 }
 945
 946 /* ---------------------------------------------------------------------- */
 947
 948 /* Given a pointer to the internal key needed by kdf() and a uhash context,
 949  * initialize the NH context and generate keys needed for poly and inner-
 950  * product hashing. All keys are endian adjusted in memory so that native
 951  * loads cause correct keys to be in registers during calculation.
 952  */
 953 static void uhash_init(uhash_ctx_t ahc, aes_int_key prf_key)
 954 {
 955     int i;
 956     UINT8 buf[(8*STREAMS+4)*sizeof(UINT64)];
 957
 958     /* Zero the entire uhash context */
 959     memset(ahc, 0, sizeof(uhash_ctx));
 960
 961     /* Initialize the L1 hash */
 962     nh_init(&ahc->hash, prf_key);
 963
 964     /* Setup L2 hash variables */
 965     kdf(buf, prf_key, 2, sizeof(buf));    /* Fill buffer with index 1 key */
 966     for (i = 0; i < STREAMS; i++) {
 967         /* Fill keys from the buffer, skipping bytes in the buffer not
 968          * used by this implementation. Endian reverse the keys if on a
 969          * little-endian computer.
 970          */
 971         memcpy(ahc->poly_key_8+i, buf+24*i, 8);
 972         endian_convert_if_le(ahc->poly_key_8+i, 8, 8);
 973         /* Mask the 64-bit keys to their special domain */
 974         ahc->poly_key_8[i] &= ((UINT64)0x01ffffffu << 32) + 0x01ffffffu;
 975         ahc->poly_accum[i] = 1;  /* Our polyhash prepends a non-zero word */
 976     }
 977
 978     /* Setup L3-1 hash variables */
 979     kdf(buf, prf_key, 3, sizeof(buf)); /* Fill buffer with index 2 key */
 980     for (i = 0; i < STREAMS; i++)
 981           memcpy(ahc->ip_keys+4*i, buf+(8*i+4)*sizeof(UINT64),
 982                                                  4*sizeof(UINT64));
 983     endian_convert_if_le(ahc->ip_keys, sizeof(UINT64),
 984                                                   sizeof(ahc->ip_keys));
 985     for (i = 0; i < STREAMS*4; i++)
 986         ahc->ip_keys[i] %= p36;  /* Bring into Z_p36 */
 987
 988     /* Setup L3-2 hash variables    */
 989     /* Fill buffer with index 4 key */
 990     kdf(ahc->ip_trans, prf_key, 4, STREAMS * sizeof(UINT32));
 991     endian_convert_if_le(ahc->ip_trans, sizeof(UINT32),
 992                          STREAMS * sizeof(UINT32));
 993 }
 994
 995 /* ---------------------------------------------------------------------- */
 996
 997 #if 0
 998 static uhash_ctx_t uhash_alloc(u_char key[])
 999 {
1000 /* Allocate memory and force to a 16-byte boundary. */
1001     uhash_ctx_t ctx;
1002     u_char bytes_to_add;
1003     aes_int_key prf_key;
1004
1005     ctx = (uhash_ctx_t)malloc(sizeof(uhash_ctx)+ALLOC_BOUNDARY);
1006     if (ctx) {
1007         if (ALLOC_BOUNDARY) {
1008             bytes_to_add = ALLOC_BOUNDARY -
1009                               ((ptrdiff_t)ctx & (ALLOC_BOUNDARY -1));
1010             ctx = (uhash_ctx_t)((u_char *)ctx + bytes_to_add);
1011             *((u_char *)ctx - 1) = bytes_to_add;
1012         }
1013         aes_key_setup(key,prf_key);
1014         uhash_init(ctx, prf_key);
1015     }
1016     return (ctx);
1017 }
1018 #endif
1019
1020 /* ---------------------------------------------------------------------- */
1021
1022 #if 0
1023 static int uhash_free(uhash_ctx_t ctx)
1024 {
1025 /* Free memory allocated by uhash_alloc */
1026     u_char bytes_to_sub;
1027
1028     if (ctx) {
1029         if (ALLOC_BOUNDARY) {
1030             bytes_to_sub = *((u_char *)ctx - 1);
1031             ctx = (uhash_ctx_t)((u_char *)ctx - bytes_to_sub);
1032         }
1033         free(ctx);
1034     }
1035     return (1);
1036 }
1037 #endif
1038 /* ---------------------------------------------------------------------- */
1039
1040 static int uhash_update(uhash_ctx_t ctx, u_char *input, long len)
1041 /* Given len bytes of data, we parse it into L1_KEY_LEN chunks and
1042  * hash each one with NH, calling the polyhash on each NH output.
1043  */
1044 {
1045     UWORD bytes_hashed, bytes_remaining;
1046     UINT64 result_buf[STREAMS];
1047     UINT8 *nh_result = (UINT8 *)&result_buf;
1048
1049     if (ctx->msg_len + len <= L1_KEY_LEN) {
1050         nh_update(&ctx->hash, (UINT8 *)input, len);
1051         ctx->msg_len += len;
1052     } else {
1053
1054          bytes_hashed = ctx->msg_len % L1_KEY_LEN;
1055          if (ctx->msg_len == L1_KEY_LEN)
1056              bytes_hashed = L1_KEY_LEN;
1057
1058          if (bytes_hashed + len >= L1_KEY_LEN) {
1059
1060              /* If some bytes have been passed to the hash function      */
1061              /* then we want to pass at most (L1_KEY_LEN - bytes_hashed) */
1062              /* bytes to complete the current nh_block.                  */
1063              if (bytes_hashed) {
1064                  bytes_remaining = (L1_KEY_LEN - bytes_hashed);
1065                  nh_update(&ctx->hash, (UINT8 *)input, bytes_remaining);
1066                  nh_final(&ctx->hash, nh_result);
1067                  ctx->msg_len += bytes_remaining;
1068                  poly_hash(ctx,(UINT32 *)nh_result);
1069                  len -= bytes_remaining;
1070                  input += bytes_remaining;
1071              }
1072
1073              /* Hash directly from input stream if enough bytes */
1074              while (len >= L1_KEY_LEN) {
1075                  nh(&ctx->hash, (UINT8 *)input, L1_KEY_LEN,
1076                                    L1_KEY_LEN, nh_result);
1077                  ctx->msg_len += L1_KEY_LEN;
1078                  len -= L1_KEY_LEN;
1079                  input += L1_KEY_LEN;
1080                  poly_hash(ctx,(UINT32 *)nh_result);
1081              }
1082          }
1083
1084          /* pass remaining < L1_KEY_LEN bytes of input data to NH */
1085          if (len) {
1086              nh_update(&ctx->hash, (UINT8 *)input, len);
1087              ctx->msg_len += len;
1088          }
1089      }
1090
1091     return (1);
1092 }
1093
1094 /* ---------------------------------------------------------------------- */
1095
1096 static int uhash_final(uhash_ctx_t ctx, u_char *res)
1097 /* Incorporate any pending data, pad, and generate tag */
1098 {
1099     UINT64 result_buf[STREAMS];
1100     UINT8 *nh_result = (UINT8 *)&result_buf;
1101
1102     if (ctx->msg_len > L1_KEY_LEN) {
1103         if (ctx->msg_len % L1_KEY_LEN) {
1104             nh_final(&ctx->hash, nh_result);
1105             poly_hash(ctx,(UINT32 *)nh_result);
1106         }
1107         ip_long(ctx, res);
1108     } else {
1109         nh_final(&ctx->hash, nh_result);
1110         ip_short(ctx,nh_result, res);
1111     }
1112     uhash_reset(ctx);
1113     return (1);
1114 }
1115
1116 /* ---------------------------------------------------------------------- */
1117
1118 #if 0
1119 static int uhash(uhash_ctx_t ahc, u_char *msg, long len, u_char *res)
1120 /* assumes that msg is in a writable buffer of length divisible by */
1121 /* L1_PAD_BOUNDARY. Bytes beyond msg[len] may be zeroed.           */
1122 {
1123     UINT8 nh_result[STREAMS*sizeof(UINT64)];
1124     UINT32 nh_len;
1125     int extra_zeroes_needed;
1126
1127     /* If the message to be hashed is no longer than L1_HASH_LEN, we skip
1128      * the polyhash.
1129      */
1130     if (len <= L1_KEY_LEN) {
1131         if (len == 0)                  /* If zero length messages will not */
1132                 nh_len = L1_PAD_BOUNDARY;  /* be seen, comment out this case   */
1133         else
1134                 nh_len = ((len + (L1_PAD_BOUNDARY - 1)) & ~(L1_PAD_BOUNDARY - 1));
1135         extra_zeroes_needed = nh_len - len;
1136         zero_pad((UINT8 *)msg + len, extra_zeroes_needed);
1137         nh(&ahc->hash, (UINT8 *)msg, nh_len, len, nh_result);
1138         ip_short(ahc,nh_result, res);
1139     } else {
1140         /* Otherwise, we hash each L1_KEY_LEN chunk with NH, passing the NH
1141          * output to poly_hash().
1142          */
1143         do {
1144             nh(&ahc->hash, (UINT8 *)msg, L1_KEY_LEN, L1_KEY_LEN, nh_result);
1145             poly_hash(ahc,(UINT32 *)nh_result);
1146             len -= L1_KEY_LEN;
1147             msg += L1_KEY_LEN;
1148         } while (len >= L1_KEY_LEN);
1149         if (len) {
1150             nh_len = ((len + (L1_PAD_BOUNDARY - 1)) & ~(L1_PAD_BOUNDARY - 1));
1151             extra_zeroes_needed = nh_len - len;
1152             zero_pad((UINT8 *)msg + len, extra_zeroes_needed);
1153             nh(&ahc->hash, (UINT8 *)msg, nh_len, len, nh_result);
1154             poly_hash(ahc,(UINT32 *)nh_result);
1155         }
1156
1157         ip_long(ahc, res);
1158     }
1159
1160     uhash_reset(ahc);
1161     return 1;
1162 }
1163 #endif
1164
1165 /* ---------------------------------------------------------------------- */
1166 /* ---------------------------------------------------------------------- */
1167 /* ----- Begin UMAC Section --------------------------------------------- */
1168 /* ---------------------------------------------------------------------- */
1169 /* ---------------------------------------------------------------------- */
1170
1171 /* The UMAC interface has two interfaces, an all-at-once interface where
1172  * the entire message to be authenticated is passed to UMAC in one buffer,
1173  * and a sequential interface where the message is presented a little at a
1174  * time. The all-at-once is more optimaized than the sequential version and
1175  * should be preferred when the sequential interface is not required.
1176  */
1177 struct umac_ctx {
1178     uhash_ctx hash;          /* Hash function for message compression    */
1179     pdf_ctx pdf;             /* PDF for hashed output                    */
1180     void *free_ptr;          /* Address to free this struct via          */
1181 } umac_ctx;
1182
1183 /* ---------------------------------------------------------------------- */
1184
1185 #if 0
1186 int umac_reset(struct umac_ctx *ctx)
1187 /* Reset the hash function to begin a new authentication.        */
1188 {
1189     uhash_reset(&ctx->hash);
1190     return (1);
1191 }
1192 #endif
1193
1194 /* ---------------------------------------------------------------------- */
1195
1196 int umac_delete(struct umac_ctx *ctx)
1197 /* Deallocate the ctx structure */
1198 {
1199     if (ctx) {
1200         if (ALLOC_BOUNDARY)
1201             ctx = (struct umac_ctx *)ctx->free_ptr;
1202         xfree(ctx);
1203     }
1204     return (1);
1205 }
1206
1207 /* ---------------------------------------------------------------------- */
1208
1209 struct umac_ctx *umac_new(u_char key[])
1210 /* Dynamically allocate a umac_ctx struct, initialize variables,
1211  * generate subkeys from key. Align to 16-byte boundary.
1212  */
1213 {
1214     struct umac_ctx *ctx, *octx;
1215     size_t bytes_to_add;
1216     aes_int_key prf_key;
1217
1218     octx = ctx = xmalloc(sizeof(*ctx) + ALLOC_BOUNDARY);
1219     if (ctx) {
1220         if (ALLOC_BOUNDARY) {
1221             bytes_to_add = ALLOC_BOUNDARY -
1222                               ((ptrdiff_t)ctx & (ALLOC_BOUNDARY - 1));
1223             ctx = (struct umac_ctx *)((u_char *)ctx + bytes_to_add);
1224         }
1225         ctx->free_ptr = octx;
1226         aes_key_setup(key,prf_key);
1227         pdf_init(&ctx->pdf, prf_key);
1228         uhash_init(&ctx->hash, prf_key);
1229     }
1230
1231     return (ctx);
1232 }
1233
1234 /* ---------------------------------------------------------------------- */
1235
1236 int umac_final(struct umac_ctx *ctx, u_char tag[], u_char nonce[8])
1237 /* Incorporate any pending data, pad, and generate tag */
1238 {
1239     uhash_final(&ctx->hash, (u_char *)tag);
1240     pdf_gen_xor(&ctx->pdf, (UINT8 *)nonce, (UINT8 *)tag);
1241
1242     return (1);
1243 }
1244
1245 /* ---------------------------------------------------------------------- */
1246
1247 int umac_update(struct umac_ctx *ctx, u_char *input, long len)
1248 /* Given len bytes of data, we parse it into L1_KEY_LEN chunks and   */
1249 /* hash each one, calling the PDF on the hashed output whenever the hash- */
1250 /* output buffer is full.                                                 */
1251 {
1252     uhash_update(&ctx->hash, input, len);
1253     return (1);
1254 }
1255
1256 /* ---------------------------------------------------------------------- */
1257
1258 #if 0
1259 int umac(struct umac_ctx *ctx, u_char *input,
1260          long len, u_char tag[],
1261          u_char nonce[8])
1262 /* All-in-one version simply calls umac_update() and umac_final().        */
1263 {
1264     uhash(&ctx->hash, input, len, (u_char *)tag);
1265     pdf_gen_xor(&ctx->pdf, (UINT8 *)nonce, (UINT8 *)tag);
1266
1267     return (1);
1268 }
1269 #endif
1270
1271 /* ---------------------------------------------------------------------- */
1272 /* ---------------------------------------------------------------------- */
1273 /* ----- End UMAC Section ----------------------------------------------- */
1274 /* ---------------------------------------------------------------------- */
1275 /* ---------------------------------------------------------------------- */