blake2s.c

/*
   BLAKE2 reference source code package - reference C implementations

   Copyright 2012, Samuel Neves <sneves@dei.uc.pt>.  You may use this under the
   terms of the CC0, the OpenSSL Licence, or the Apache Public License 2.0, at
   your option.  The terms of these licenses can be found at:

   - CC0 1.0 Universal : http://creativecommons.org/publicdomain/zero/1.0
   - OpenSSL license   : https://www.openssl.org/source/license.html
   - Apache 2.0        : http://www.apache.org/licenses/LICENSE-2.0

   More information about the BLAKE2 hash function can be found at
   https://blake2.net.
*/

#include <string.h>

#include "blake2_common.h"
#include "blake2s.h"
#include "memzero.h"
#include "options.h"

typedef struct blake2s_param__ {
  uint8_t digest_length; /* 1 */
  uint8_t key_length;    /* 2 */
  uint8_t fanout;        /* 3 */
  uint8_t depth;         /* 4 */
  uint32_t leaf_length;  /* 8 */
  uint32_t node_offset;  /* 12 */
  uint16_t xof_length;   /* 14 */
  uint8_t node_depth;    /* 15 */
  uint8_t inner_length;  /* 16 */
  /* uint8_t  reserved[0]; */
  uint8_t salt[BLAKE2S_SALTBYTES];         /* 24 */
  uint8_t personal[BLAKE2S_PERSONALBYTES]; /* 32 */
} __attribute__((packed)) blake2s_param;

static const uint32_t blake2s_IV[8] = {0x6A09E667UL, 0xBB67AE85UL, 0x3C6EF372UL,
                                       0xA54FF53AUL, 0x510E527FUL, 0x9B05688CUL,
                                       0x1F83D9ABUL, 0x5BE0CD19UL};

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},
};

static void blake2s_set_lastnode(blake2s_state *S) { S->f[1] = (uint32_t)-1; }

/* Some helper functions, not necessarily useful */
static int blake2s_is_lastblock(const blake2s_state *S) { return S->f[0] != 0; }

static void blake2s_set_lastblock(blake2s_state *S) {
  if (S->last_node) blake2s_set_lastnode(S);

  S->f[0] = (uint32_t)-1;
}

static void blake2s_increment_counter(blake2s_state *S, const uint32_t inc) {
  S->t[0] += inc;
  S->t[1] += (S->t[0] < inc);
}

static void blake2s_init0(blake2s_state *S) {
  size_t i = 0;
  memzero(S, sizeof(blake2s_state));

  for (i = 0; i < 8; ++i) S->h[i] = blake2s_IV[i];
}

/* init2 xors IV with input parameter block */
int blake2s_init_param(blake2s_state *S, const blake2s_param *P) {
  const unsigned char *p = (const unsigned char *)(P);
  size_t i = 0;

  blake2s_init0(S);

  /* IV XOR ParamBlock */
  for (i = 0; i < 8; ++i) S->h[i] ^= load32(&p[i * 4]);

  S->outlen = P->digest_length;
  return 0;
}

/* Sequential blake2s initialization */
int blake2s_Init(blake2s_state *S, size_t outlen) {
  blake2s_param P[1] = {0};

  if ((!outlen) || (outlen > BLAKE2S_OUTBYTES)) return -1;

  P->digest_length = (uint8_t)outlen;
  P->key_length = 0;
  P->fanout = 1;
  P->depth = 1;
  store32(&P->leaf_length, 0);
  store32(&P->node_offset, 0);
  store16(&P->xof_length, 0);
  P->node_depth = 0;
  P->inner_length = 0;
  /* memzero(P->reserved, sizeof(P->reserved) ); */
  memzero(P->salt, sizeof(P->salt));
  memzero(P->personal, sizeof(P->personal));
  return blake2s_init_param(S, P);
}

int blake2s_InitPersonal(blake2s_state *S, size_t outlen, const void *personal,
                         size_t personal_len) {
  blake2s_param P[1] = {0};

  if ((!outlen) || (outlen > BLAKE2S_OUTBYTES)) return -1;
  if ((!personal) || (personal_len != BLAKE2S_PERSONALBYTES)) return -1;

  P->digest_length = (uint8_t)outlen;
  P->key_length = 0;
  P->fanout = 1;
  P->depth = 1;
  store32(&P->leaf_length, 0);
  store32(&P->node_offset, 0);
  store16(&P->xof_length, 0);
  P->node_depth = 0;
  P->inner_length = 0;
  /* memzero(P->reserved, sizeof(P->reserved) ); */
  memzero(P->salt, sizeof(P->salt));
  memcpy(P->personal, personal, BLAKE2S_PERSONALBYTES);
  return blake2s_init_param(S, P);
}

int blake2s_InitKey(blake2s_state *S, size_t outlen, const void *key,
                    size_t keylen) {
  blake2s_param P[1] = {0};

  if ((!outlen) || (outlen > BLAKE2S_OUTBYTES)) return -1;

  if (!key || !keylen || keylen > BLAKE2S_KEYBYTES) return -1;

  P->digest_length = (uint8_t)outlen;
  P->key_length = (uint8_t)keylen;
  P->fanout = 1;
  P->depth = 1;
  store32(&P->leaf_length, 0);
  store32(&P->node_offset, 0);
  store16(&P->xof_length, 0);
  P->node_depth = 0;
  P->inner_length = 0;
  /* memzero(P->reserved, sizeof(P->reserved) ); */
  memzero(P->salt, sizeof(P->salt));
  memzero(P->personal, sizeof(P->personal));

  if (blake2s_init_param(S, P) < 0) return -1;

  {
    uint8_t block[BLAKE2S_BLOCKBYTES] = {0};
    memzero(block, BLAKE2S_BLOCKBYTES);
    memcpy(block, key, keylen);
    blake2s_Update(S, block, BLAKE2S_BLOCKBYTES);
    memzero(block, BLAKE2S_BLOCKBYTES); /* Burn the key from stack */
  }
  return 0;
}

#define G(m, 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)

#if OPTIMIZE_SIZE_BLAKE2S
static void g(uint32_t *m, int r, int i, uint32_t *a, uint32_t *b, uint32_t *c,
              uint32_t *d) {
  G(m, r, i, a, b, c, d);
}
#else
#define g(m, r, i, a, b, c, d) G(m, r, i, a, b, c, d)
#endif

#define ROUND(m, v, r)                        \
  do {                                        \
    g(m, r, 0, v + 0, v + 4, v + 8, v + 12);  \
    g(m, r, 1, v + 1, v + 5, v + 9, v + 13);  \
    g(m, r, 2, v + 2, v + 6, v + 10, v + 14); \
    g(m, r, 3, v + 3, v + 7, v + 11, v + 15); \
    g(m, r, 4, v + 0, v + 5, v + 10, v + 15); \
    g(m, r, 5, v + 1, v + 6, v + 11, v + 12); \
    g(m, r, 6, v + 2, v + 7, v + 8, v + 13);  \
    g(m, r, 7, v + 3, v + 4, v + 9, v + 14);  \
  } while (0)

static void blake2s_compress(blake2s_state *S,
                             const uint8_t in[BLAKE2S_BLOCKBYTES]) {
  uint32_t m[16] = {0};
  uint32_t v[16] = {0};
  size_t i = 0;

  for (i = 0; i < 16; ++i) {
    m[i] = load32(in + i * sizeof(m[i]));
  }

  for (i = 0; i < 8; ++i) {
    v[i] = S->h[i];
  }

  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];

#if OPTIMIZE_SIZE_BLAKE2S
  for (int r = 0; r < 10; r++) {
    ROUND(m, v, r);
  }
#else
  ROUND(m, v, 0);
  ROUND(m, v, 1);
  ROUND(m, v, 2);
  ROUND(m, v, 3);
  ROUND(m, v, 4);
  ROUND(m, v, 5);
  ROUND(m, v, 6);
  ROUND(m, v, 7);
  ROUND(m, v, 8);
  ROUND(m, v, 9);
#endif

  for (i = 0; i < 8; ++i) {
    S->h[i] = S->h[i] ^ v[i] ^ v[i + 8];
  }
}

#undef G
#undef ROUND

int blake2s_Update(blake2s_state *S, const void *pin, size_t inlen) {
  const unsigned char *in = (const unsigned char *)pin;
  if (inlen > 0) {
    size_t left = S->buflen;
    size_t fill = BLAKE2S_BLOCKBYTES - left;
    if (inlen > fill) {
      S->buflen = 0;
      memcpy(S->buf + left, in, fill); /* Fill buffer */
      blake2s_increment_counter(S, BLAKE2S_BLOCKBYTES);
      blake2s_compress(S, S->buf); /* Compress */
      in += fill;
      inlen -= fill;
      while (inlen > BLAKE2S_BLOCKBYTES) {
        blake2s_increment_counter(S, BLAKE2S_BLOCKBYTES);
        blake2s_compress(S, in);
        in += BLAKE2S_BLOCKBYTES;
        inlen -= BLAKE2S_BLOCKBYTES;
      }
    }
    memcpy(S->buf + S->buflen, in, inlen);
    S->buflen += inlen;
  }
  return 0;
}

int blake2s_Final(blake2s_state *S, void *out, size_t outlen) {
  uint8_t buffer[BLAKE2S_OUTBYTES] = {0};
  size_t i = 0;

  if (out == NULL || outlen < S->outlen) return -1;

  if (blake2s_is_lastblock(S)) return -1;

  blake2s_increment_counter(S, (uint32_t)S->buflen);
  blake2s_set_lastblock(S);
  memzero(S->buf + S->buflen, BLAKE2S_BLOCKBYTES - S->buflen); /* Padding */
  blake2s_compress(S, S->buf);

  for (i = 0; i < 8; ++i) /* Output full hash to temp buffer */
    store32(buffer + sizeof(S->h[i]) * i, S->h[i]);

  memcpy(out, buffer, outlen);
  memzero(buffer, sizeof(buffer));
  return 0;
}

int blake2s(const uint8_t *msg, uint32_t msg_len, void *out, size_t outlen) {
  BLAKE2S_CTX ctx;
  if (0 != blake2s_Init(&ctx, outlen)) return -1;
  if (0 != blake2s_Update(&ctx, msg, msg_len)) return -1;
  if (0 != blake2s_Final(&ctx, out, outlen)) return -1;
  return 0;
}

int blake2s_Key(const uint8_t *msg, uint32_t msg_len, const void *key,
                size_t keylen, void *out, size_t outlen) {
  BLAKE2S_CTX ctx;
  if (0 != blake2s_InitKey(&ctx, outlen, key, keylen)) return -1;
  if (0 != blake2s_Update(&ctx, msg, msg_len)) return -1;
  if (0 != blake2s_Final(&ctx, out, outlen)) return -1;
  return 0;
}