text: /*
   * Copyright 2016-2019 The OpenSSL Project Authors. All Rights Reserved.
   *
   * Licensed under the Apache License 2.0 (the "License").  You may not use
   * this file except in compliance with the License.  You can obtain a copy
   * in the file LICENSE in the source distribution or at
   * https://www.openssl.org/source/license.html
   */
  
  /*
   * Derived from the BLAKE2 reference implementation written by Samuel Neves.
   * Copyright 2012, Samuel Neves <sneves@dei.uc.pt>
   * More information about the BLAKE2 hash function and its implementations
   * can be found at https://blake2.net.
   */
  
  #include <assert.h>
  #include <string.h>
  #include <openssl/crypto.h>
  #include "blake2_impl.h"
  #include "prov/blake2.h"
  
  static const uint32_t blake2s_IV[8] =
  {
      0x6A09E667U, 0xBB67AE85U, 0x3C6EF372U, 0xA54FF53AU,
      0x510E527FU, 0x9B05688CU, 0x1F83D9ABU, 0x5BE0CD19U
  };
  
  static const uint8_t blake2s_sigma[10][16] =
  {
      {  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15 } ,
      { 14, 10,  4,  8,  9, 15, 13,  6,  1, 12,  0,  2, 11,  7,  5,  3 } ,
      { 11,  8, 12,  0,  5,  2, 15, 13, 10, 14,  3,  6,  7,  1,  9,  4 } ,
      {  7,  9,  3,  1, 13, 12, 11, 14,  2,  6,  5, 10,  4,  0, 15,  8 } ,
      {  9,  0,  5,  7,  2,  4, 10, 15, 14,  1, 11, 12,  6,  8,  3, 13 } ,
      {  2, 12,  6, 10,  0, 11,  8,  3,  4, 13,  7,  5, 15, 14,  1,  9 } ,
      { 12,  5,  1, 15, 14, 13,  4, 10,  0,  7,  6,  3,  9,  2,  8, 11 } ,
      { 13, 11,  7, 14, 12,  1,  3,  9,  5,  0, 15,  4,  8,  6,  2, 10 } ,
      {  6, 15, 14,  9, 11,  3,  0,  8, 12,  2, 13,  7,  1,  4, 10,  5 } ,
      { 10,  2,  8,  4,  7,  6,  1,  5, 15, 11,  9, 14,  3, 12, 13 , 0 } ,
  };
  
  /* Set that it's the last block we'll compress */
  static ossl_inline void blake2s_set_lastblock(BLAKE2S_CTX *S)
  {
      S->f[0] = -1;
  }
  
  /* Initialize the hashing state. */
  static ossl_inline void blake2s_init0(BLAKE2S_CTX *S)
  {
      int i;
  
      memset(S, 0, sizeof(BLAKE2S_CTX));
      for (i = 0; i < 8; ++i) {
          S->h[i] = blake2s_IV[i];
      }
  }
  
  /* init xors IV with input parameter block and sets the output length */
  static void blake2s_init_param(BLAKE2S_CTX *S, const BLAKE2S_PARAM *P)
  {
      size_t i;
      const uint8_t *p = (const uint8_t *)(P);
  
      blake2s_init0(S);
      S->outlen = P->digest_length;
  
      /* The param struct is carefully hand packed, and should be 32 bytes on
       * every platform. */
      assert(sizeof(BLAKE2S_PARAM) == 32);
      /* IV XOR ParamBlock */
      for (i = 0; i < 8; ++i) {
          S->h[i] ^= load32(&p[i*4]);
      }
  }
  
  void blake2s_param_init(BLAKE2S_PARAM *P)
  {
      P->digest_length = BLAKE2S_DIGEST_LENGTH;
      P->key_length    = 0;
      P->fanout        = 1;
      P->depth         = 1;
      store32(P->leaf_length, 0);
      store48(P->node_offset, 0);
      P->node_depth    = 0;
      P->inner_length  = 0;
      memset(P->salt,     0, sizeof(P->salt));
      memset(P->personal, 0, sizeof(P->personal));
  }
  
  void blake2s_param_set_digest_length(BLAKE2S_PARAM *P, uint8_t outlen)
  {
      P->digest_length = outlen;
  }
  
  void blake2s_param_set_key_length(BLAKE2S_PARAM *P, uint8_t keylen)
  {
      P->key_length = keylen;
  }
  
  void blake2s_param_set_personal(BLAKE2S_PARAM *P, const uint8_t *personal, size_t len)
  {
      memcpy(P->personal, personal, len);
      memset(P->personal + len, 0, BLAKE2S_PERSONALBYTES - len);
  }
  
  void blake2s_param_set_salt(BLAKE2S_PARAM *P, const uint8_t *salt, size_t len)
  {
      memcpy(P->salt, salt, len);
      memset(P->salt + len, 0, BLAKE2S_SALTBYTES - len);}
  
  /*
   * Initialize the hashing context with the given parameter block.
   * Always returns 1.
   */
  int blake2s_init(BLAKE2S_CTX *c, const BLAKE2S_PARAM *P)
  {
      blake2s_init_param(c, P);
      return 1;
  }
  
  /*
   * Initialize the hashing context with the given parameter block and key.
   * Always returns 1.
   */
  int blake2s_init_key(BLAKE2S_CTX *c, const BLAKE2S_PARAM *P, const void *key)
  {
      blake2s_init_param(c, P);
  
      /* Pad the key to form first data block */
      {
          uint8_t block[BLAKE2S_BLOCKBYTES] = {0};
  
          memcpy(block, key, P->key_length);
          blake2s_update(c, block, BLAKE2S_BLOCKBYTES);
          OPENSSL_cleanse(block, BLAKE2S_BLOCKBYTES);
      }
  
      return 1;
  }
  
  /* Permute the state while xoring in the block of data. */
  static void blake2s_compress(BLAKE2S_CTX *S,
                              const uint8_t *blocks,
                              size_t len)
  {
      uint32_t m[16];
      uint32_t v[16];
      size_t i;
      size_t increment;
  
      /*
       * There are two distinct usage vectors for this function:
       *
       * a) BLAKE2s_Update uses it to process complete blocks,
       *    possibly more than one at a time;
       *
       * b) BLAK2s_Final uses it to process last block, always
       *    single but possibly incomplete, in which case caller
       *    pads input with zeros.
       */
      assert(len < BLAKE2S_BLOCKBYTES || len % BLAKE2S_BLOCKBYTES == 0);
  
      /*
       * Since last block is always processed with separate call,
       * |len| not being multiple of complete blocks can be observed
       * only with |len| being less than BLAKE2S_BLOCKBYTES ("less"
       * including even zero), which is why following assignment doesn't
       * have to reside inside the main loop below.
       */
      increment = len < BLAKE2S_BLOCKBYTES ? len : BLAKE2S_BLOCKBYTES;
  
      for (i = 0; i < 8; ++i) {
          v[i] = S->h[i];
      }
  
      do {
          for (i = 0; i < 16; ++i) {
              m[i] = load32(blocks + i * sizeof(m[i]));
          }
  
          /* blake2s_increment_counter */
          S->t[0] += increment;
          S->t[1] += (S->t[0] < increment);
  
          v[ 8] = blake2s_IV[0];
          v[ 9] = blake2s_IV[1];
          v[10] = blake2s_IV[2];
          v[11] = blake2s_IV[3];
          v[12] = S->t[0] ^ blake2s_IV[4];
          v[13] = S->t[1] ^ blake2s_IV[5];
          v[14] = S->f[0] ^ blake2s_IV[6];
          v[15] = S->f[1] ^ blake2s_IV[7];
  #define G(r,i,a,b,c,d) \
          do { \
              a = a + b + m[blake2s_sigma[r][2*i+0]]; \
              d = rotr32(d ^ a, 16); \
              c = c + d; \
              b = rotr32(b ^ c, 12); \
              a = a + b + m[blake2s_sigma[r][2*i+1]]; \
              d = rotr32(d ^ a, 8); \
              c = c + d; \
              b = rotr32(b ^ c, 7); \
          } while (0)
  #define ROUND(r)  \
          do { \
              G(r,0,v[ 0],v[ 4],v[ 8],v[12]); \
              G(r,1,v[ 1],v[ 5],v[ 9],v[13]); \
              G(r,2,v[ 2],v[ 6],v[10],v[14]); \
              G(r,3,v[ 3],v[ 7],v[11],v[15]); \
              G(r,4,v[ 0],v[ 5],v[10],v[15]); \
              G(r,5,v[ 1],v[ 6],v[11],v[12]); \
              G(r,6,v[ 2],v[ 7],v[ 8],v[13]); \
              G(r,7,v[ 3],v[ 4],v[ 9],v[14]); \
          } while (0)
  #if defined(OPENSSL_SMALL_FOOTPRINT)
          /* almost 3x reduction on x86_64, 4.5x on ARMv8, 4x on ARMv4 */
          for (i = 0; i < 10; i++) {
              ROUND(i);
          }
  #else
          ROUND(0);
          ROUND(1);
          ROUND(2);
          ROUND(3);
          ROUND(4);
          ROUND(5);
          ROUND(6);
          ROUND(7);
          ROUND(8);
          ROUND(9);
  #endif
  
          for (i = 0; i < 8; ++i) {
              S->h[i] = v[i] ^= v[i + 8] ^ S->h[i];
          }
  #undef G
  #undef ROUND
          blocks += increment;
          len -= increment;
      } while (len);
  }
  
  /* Absorb the input data into the hash state.  Always returns 1. */
  int blake2s_update(BLAKE2S_CTX *c, const void *data, size_t datalen)
  {
      const uint8_t *in = (const uint8_t *)data;
      size_t fill;
  
      /*
       * Intuitively one would expect intermediate buffer, c->buf, to
       * store incomplete blocks. But in this case we are interested to
       * temporarily stash even complete blocks, because last one in the
       * stream has to be treated in special way, and at this point we
       * don't know if last block in *this* call is last one "ever". This
       * is the reason for why |datalen| is compared as >, and not >=.
       */
      fill = sizeof(c->buf) - c->buflen;
      if (datalen > fill) {
          if (c->buflen) {
              memcpy(c->buf + c->buflen, in, fill); /* Fill buffer */
              blake2s_compress(c, c->buf, BLAKE2S_BLOCKBYTES);
              c->buflen = 0;
              in += fill;
              datalen -= fill;
          }
          if (datalen > BLAKE2S_BLOCKBYTES) {
              size_t stashlen = datalen % BLAKE2S_BLOCKBYTES;
              /*
               * If |datalen| is a multiple of the blocksize, stash
               * last complete block, it can be final one...
               */
              stashlen = stashlen ? stashlen : BLAKE2S_BLOCKBYTES;
              datalen -= stashlen;
              blake2s_compress(c, in, datalen);
              in += datalen;
              datalen = stashlen;
          }
      }
  
      assert(datalen <= BLAKE2S_BLOCKBYTES);
  
      memcpy(c->buf + c->buflen, in, datalen);
      c->buflen += datalen; /* Be lazy, do not compress */
  
      return 1;
  }
  
  /*
   * Calculate the final hash and save it in md.
   * Always returns 1.
   */
  int blake2s_final(unsigned char *md, BLAKE2S_CTX *c)
  {
      uint8_t outbuffer[BLAKE2S_OUTBYTES] = {0};
      uint8_t *target = outbuffer;
      int iter = (int)((c->outlen + 3) / 4);
      int i;
  
      /* Avoid writing to the temporary buffer if possible */
      if ((c->outlen % sizeof(c->h[0])) == 0)
          target = md;
  
      blake2s_set_lastblock(c);
      /* Padding */
      memset(c->buf + c->buflen, 0, sizeof(c->buf) - c->buflen);
      blake2s_compress(c, c->buf, c->buflen);
  
      /* Output full hash to buffer */
      for (i = 0; i < iter; ++i)
          store32(target + sizeof(c->h[i]) * i, c->h[i]);
  
      if (target != md)
          memcpy(md, target, c->outlen);
  
      OPENSSL_cleanse(c, sizeof(BLAKE2S_CTX));
      return 1;
  }
  