/* SPDX-License-Identifier: Apache-2.0
 * Copyright(c) 2024 Cisco Systems, Inc.
 */

#ifndef included_sha2_h
#define included_sha2_h

#include <vppinfra/clib.h>
#include <vppinfra/vector.h>
#include <vppinfra/string.h>

#define SHA256_ROTR(x, y)   ((x >> y) | (x << (32 - y)))
#define SHA256_CH(a, b, c)  ((a & b) ^ (~a & c))
#define SHA256_MAJ(a, b, c) ((a & b) ^ (a & c) ^ (b & c))
#define SHA256_CSIGMA0(x)                                                     \
  (SHA256_ROTR (x, 2) ^ SHA256_ROTR (x, 13) ^ SHA256_ROTR (x, 22));
#define SHA256_CSIGMA1(x)                                                     \
  (SHA256_ROTR (x, 6) ^ SHA256_ROTR (x, 11) ^ SHA256_ROTR (x, 25));
#define SHA256_SSIGMA0(x) (SHA256_ROTR (x, 7) ^ SHA256_ROTR (x, 18) ^ (x >> 3))
#define SHA256_SSIGMA1(x)                                                     \
  (SHA256_ROTR (x, 17) ^ SHA256_ROTR (x, 19) ^ (x >> 10))

#define SHA256_MSG_SCHED(w, j)                                                \
  {                                                                           \
    w[j] = w[j - 7] + w[j - 16];                                              \
    w[j] += SHA256_SSIGMA0 (w[j - 15]);                                       \
    w[j] += SHA256_SSIGMA1 (w[j - 2]);                                        \
  }

#define SHA256_TRANSFORM(s, w, i, k)                                          \
  {                                                                           \
    __typeof__ (s[0]) t1, t2;                                                 \
    t1 = k + w[i] + s[7];                                                     \
    t1 += SHA256_CSIGMA1 (s[4]);                                              \
    t1 += SHA256_CH (s[4], s[5], s[6]);                                       \
    t2 = SHA256_CSIGMA0 (s[0]);                                               \
    t2 += SHA256_MAJ (s[0], s[1], s[2]);                                      \
    s[7] = s[6];                                                              \
    s[6] = s[5];                                                              \
    s[5] = s[4];                                                              \
    s[4] = s[3] + t1;                                                         \
    s[3] = s[2];                                                              \
    s[2] = s[1];                                                              \
    s[1] = s[0];                                                              \
    s[0] = t1 + t2;                                                           \
  }

#define SHA512_ROTR(x, y)   ((x >> y) | (x << (64 - y)))
#define SHA512_CH(a, b, c)  ((a & b) ^ (~a & c))
#define SHA512_MAJ(a, b, c) ((a & b) ^ (a & c) ^ (b & c))
#define SHA512_CSIGMA0(x)                                                     \
  (SHA512_ROTR (x, 28) ^ SHA512_ROTR (x, 34) ^ SHA512_ROTR (x, 39))
#define SHA512_CSIGMA1(x)                                                     \
  (SHA512_ROTR (x, 14) ^ SHA512_ROTR (x, 18) ^ SHA512_ROTR (x, 41))
#define SHA512_SSIGMA0(x) (SHA512_ROTR (x, 1) ^ SHA512_ROTR (x, 8) ^ (x >> 7))
#define SHA512_SSIGMA1(x)                                                     \
  (SHA512_ROTR (x, 19) ^ SHA512_ROTR (x, 61) ^ (x >> 6))

#define SHA512_MSG_SCHED(w, j)                                                \
  {                                                                           \
    w[j] = w[j - 7] + w[j - 16];                                              \
    w[j] += SHA512_SSIGMA0 (w[j - 15]);                                       \
    w[j] += SHA512_SSIGMA1 (w[j - 2]);                                        \
  }

#define SHA512_TRANSFORM(s, w, i, k)                                          \
  {                                                                           \
    __typeof__ (s[0]) t1, t2;                                                 \
    t1 = k + w[i] + s[7];                                                     \
    t1 += SHA512_CSIGMA1 (s[4]);                                              \
    t1 += SHA512_CH (s[4], s[5], s[6]);                                       \
    t2 = SHA512_CSIGMA0 (s[0]);                                               \
    t2 += SHA512_MAJ (s[0], s[1], s[2]);                                      \
    s[7] = s[6];                                                              \
    s[6] = s[5];                                                              \
    s[5] = s[4];                                                              \
    s[4] = s[3] + t1;                                                         \
    s[3] = s[2];                                                              \
    s[2] = s[1];                                                              \
    s[1] = s[0];                                                              \
    s[0] = t1 + t2;                                                           \
  }

#if defined(__SHA__) && defined(__x86_64__)
#define CLIB_SHA256_ISA_INTEL
#define CLIB_SHA256_ISA
#endif

#ifdef __ARM_FEATURE_SHA2
#define CLIB_SHA256_ISA_ARM
#define CLIB_SHA256_ISA
#endif

static const u32 sha224_h[8] = { 0xc1059ed8, 0x367cd507, 0x3070dd17,
				 0xf70e5939, 0xffc00b31, 0x68581511,
				 0x64f98fa7, 0xbefa4fa4 };

static const u32 sha256_h[8] = { 0x6a09e667, 0xbb67ae85, 0x3c6ef372,
				 0xa54ff53a, 0x510e527f, 0x9b05688c,
				 0x1f83d9ab, 0x5be0cd19 };

static const u32 clib_sha2_256_k[64] = {
  0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1,
  0x923f82a4, 0xab1c5ed5, 0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,
  0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174, 0xe49b69c1, 0xefbe4786,
  0x0fc19dc6, 0x240ca1cc, 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
  0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, 0xc6e00bf3, 0xd5a79147,
  0x06ca6351, 0x14292967, 0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,
  0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85, 0xa2bfe8a1, 0xa81a664b,
  0xc24b8b70, 0xc76c51a3, 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
  0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a,
  0x5b9cca4f, 0x682e6ff3, 0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,
  0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
};

static const u64 sha384_h[8] = { 0xcbbb9d5dc1059ed8, 0x629a292a367cd507,
				 0x9159015a3070dd17, 0x152fecd8f70e5939,
				 0x67332667ffc00b31, 0x8eb44a8768581511,
				 0xdb0c2e0d64f98fa7, 0x47b5481dbefa4fa4 };

static const u64 sha512_h[8] = { 0x6a09e667f3bcc908, 0xbb67ae8584caa73b,
				 0x3c6ef372fe94f82b, 0xa54ff53a5f1d36f1,
				 0x510e527fade682d1, 0x9b05688c2b3e6c1f,
				 0x1f83d9abfb41bd6b, 0x5be0cd19137e2179 };

static const u64 sha512_224_h[8] = { 0x8c3d37c819544da2, 0x73e1996689dcd4d6,
				     0x1dfab7ae32ff9c82, 0x679dd514582f9fcf,
				     0x0f6d2b697bd44da8, 0x77e36f7304c48942,
				     0x3f9d85a86a1d36c8, 0x1112e6ad91d692a1 };

static const u64 sha512_256_h[8] = { 0x22312194fc2bf72c, 0x9f555fa3c84c64c2,
				     0x2393b86b6f53b151, 0x963877195940eabd,
				     0x96283ee2a88effe3, 0xbe5e1e2553863992,
				     0x2b0199fc2c85b8aa, 0x0eb72ddc81c52ca2 };

static const u64 clib_sha2_512_k[80] = {
  0x428a2f98d728ae22, 0x7137449123ef65cd, 0xb5c0fbcfec4d3b2f,
  0xe9b5dba58189dbbc, 0x3956c25bf348b538, 0x59f111f1b605d019,
  0x923f82a4af194f9b, 0xab1c5ed5da6d8118, 0xd807aa98a3030242,
  0x12835b0145706fbe, 0x243185be4ee4b28c, 0x550c7dc3d5ffb4e2,
  0x72be5d74f27b896f, 0x80deb1fe3b1696b1, 0x9bdc06a725c71235,
  0xc19bf174cf692694, 0xe49b69c19ef14ad2, 0xefbe4786384f25e3,
  0x0fc19dc68b8cd5b5, 0x240ca1cc77ac9c65, 0x2de92c6f592b0275,
  0x4a7484aa6ea6e483, 0x5cb0a9dcbd41fbd4, 0x76f988da831153b5,
  0x983e5152ee66dfab, 0xa831c66d2db43210, 0xb00327c898fb213f,
  0xbf597fc7beef0ee4, 0xc6e00bf33da88fc2, 0xd5a79147930aa725,
  0x06ca6351e003826f, 0x142929670a0e6e70, 0x27b70a8546d22ffc,
  0x2e1b21385c26c926, 0x4d2c6dfc5ac42aed, 0x53380d139d95b3df,
  0x650a73548baf63de, 0x766a0abb3c77b2a8, 0x81c2c92e47edaee6,
  0x92722c851482353b, 0xa2bfe8a14cf10364, 0xa81a664bbc423001,
  0xc24b8b70d0f89791, 0xc76c51a30654be30, 0xd192e819d6ef5218,
  0xd69906245565a910, 0xf40e35855771202a, 0x106aa07032bbd1b8,
  0x19a4c116b8d2d0c8, 0x1e376c085141ab53, 0x2748774cdf8eeb99,
  0x34b0bcb5e19b48a8, 0x391c0cb3c5c95a63, 0x4ed8aa4ae3418acb,
  0x5b9cca4f7763e373, 0x682e6ff3d6b2b8a3, 0x748f82ee5defb2fc,
  0x78a5636f43172f60, 0x84c87814a1f0ab72, 0x8cc702081a6439ec,
  0x90befffa23631e28, 0xa4506cebde82bde9, 0xbef9a3f7b2c67915,
  0xc67178f2e372532b, 0xca273eceea26619c, 0xd186b8c721c0c207,
  0xeada7dd6cde0eb1e, 0xf57d4f7fee6ed178, 0x06f067aa72176fba,
  0x0a637dc5a2c898a6, 0x113f9804bef90dae, 0x1b710b35131c471b,
  0x28db77f523047d84, 0x32caab7b40c72493, 0x3c9ebe0a15c9bebc,
  0x431d67c49c100d4c, 0x4cc5d4becb3e42b6, 0x597f299cfc657e2a,
  0x5fcb6fab3ad6faec, 0x6c44198c4a475817
};

typedef enum
{
  CLIB_SHA2_224,
  CLIB_SHA2_256,
  CLIB_SHA2_384,
  CLIB_SHA2_512,
  CLIB_SHA2_512_224,
  CLIB_SHA2_512_256,
} clib_sha2_type_t;

#define CLIB_SHA2_256_BLOCK_SIZE 64
#define CLIB_SHA2_512_BLOCK_SIZE 128
#define SHA2_MAX_BLOCK_SIZE	 CLIB_SHA2_512_BLOCK_SIZE
#define SHA2_MAX_DIGEST_SIZE	 64

static const struct
{
  u8 block_size;
  u8 digest_size;
  const u32 *h32;
  const u64 *h64;
} clib_sha2_variants[] = {
  [CLIB_SHA2_224] = {
    .block_size = CLIB_SHA2_256_BLOCK_SIZE,
    .digest_size = 28,
    .h32 = sha224_h,
  },
  [CLIB_SHA2_256] = {
    .block_size = CLIB_SHA2_256_BLOCK_SIZE,
    .digest_size = 32,
    .h32 = sha256_h,
  },
  [CLIB_SHA2_384] = {
    .block_size = CLIB_SHA2_512_BLOCK_SIZE,
    .digest_size = 48,
    .h64 = sha384_h,
  },
  [CLIB_SHA2_512] = {
    .block_size = CLIB_SHA2_512_BLOCK_SIZE,
    .digest_size = 64,
    .h64 = sha512_h,
  },
  [CLIB_SHA2_512_224] = {
    .block_size = CLIB_SHA2_512_BLOCK_SIZE,
    .digest_size = 28,
    .h64 = sha512_224_h,
  },
  [CLIB_SHA2_512_256] = {
    .block_size = CLIB_SHA2_512_BLOCK_SIZE,
    .digest_size = 32,
    .h64 = sha512_256_h,
  },
};

typedef union
{
  u32 h32[8];
  u64 h64[8];
#ifdef CLIB_SHA256_ISA
  u32x4 h32x4[2];
#endif
} clib_sha2_h_t;

typedef struct
{
  u64 total_bytes;
  u16 n_pending;
  clib_sha2_h_t h;
  union
  {
    u8 as_u8[SHA2_MAX_BLOCK_SIZE];
    u64 as_u64[SHA2_MAX_BLOCK_SIZE / sizeof (u64)];
    uword as_uword[SHA2_MAX_BLOCK_SIZE / sizeof (uword)];
  } pending;
} clib_sha2_state_t;

typedef struct
{
  clib_sha2_type_t type;
  u8 block_size;
  u8 digest_size;
  clib_sha2_state_t state;
} clib_sha2_ctx_t;

static_always_inline void
clib_sha2_state_init (clib_sha2_state_t *state, clib_sha2_type_t type)
{
  clib_sha2_state_t st = {};

  if (clib_sha2_variants[type].block_size == CLIB_SHA2_256_BLOCK_SIZE)
    for (int i = 0; i < 8; i++)
      st.h.h32[i] = clib_sha2_variants[type].h32[i];
  else
    for (int i = 0; i < 8; i++)
      st.h.h64[i] = clib_sha2_variants[type].h64[i];

  *state = st;
}

static_always_inline void
clib_sha2_init (clib_sha2_ctx_t *ctx, clib_sha2_type_t type)
{
  clib_sha2_state_init (&ctx->state, type);
  ctx->block_size = clib_sha2_variants[type].block_size;
  ctx->digest_size = clib_sha2_variants[type].digest_size;
  ctx->type = type;
}

#ifdef CLIB_SHA256_ISA
static inline void
clib_sha256_vec_cycle_w (u32x4 w[], u8 i)
{
  u8 j = (i + 1) % 4;
  u8 k = (i + 2) % 4;
  u8 l = (i + 3) % 4;
#ifdef CLIB_SHA256_ISA_INTEL
  w[i] = (u32x4) _mm_sha256msg1_epu32 ((__m128i) w[i], (__m128i) w[j]);
  w[i] += (u32x4) _mm_alignr_epi8 ((__m128i) w[l], (__m128i) w[k], 4);
  w[i] = (u32x4) _mm_sha256msg2_epu32 ((__m128i) w[i], (__m128i) w[l]);
#elif defined(CLIB_SHA256_ISA_ARM)
  w[i] = vsha256su1q_u32 (vsha256su0q_u32 (w[i], w[j]), w[k], w[l]);
#endif
}

static inline void
clib_sha256_vec_4_rounds (u32x4 w, u8 n, u32x4 s[])
{
#ifdef CLIB_SHA256_ISA_INTEL
  u32x4 r = *(u32x4 *) (clib_sha2_256_k + 4 * n) + w;
  s[0] = (u32x4) _mm_sha256rnds2_epu32 ((__m128i) s[0], (__m128i) s[1],
					(__m128i) r);
  r = (u32x4) u64x2_interleave_hi ((u64x2) r, (u64x2) r);
  s[1] = (u32x4) _mm_sha256rnds2_epu32 ((__m128i) s[1], (__m128i) s[0],
					(__m128i) r);
#elif defined(CLIB_SHA256_ISA_ARM)
  u32x4 r0, s0;
  const u32x4u *k = (u32x4u *) clib_sha2_256_k;

  r0 = w + k[n];
  s0 = s[0];
  s[0] = vsha256hq_u32 (s[0], s[1], r0);
  s[1] = vsha256h2q_u32 (s[1], s0, r0);
#endif
}
#endif

#if defined(CLIB_SHA256_ISA)
static inline u32x4
clib_sha256_vec_load (u32x4 r)
{
#if defined(CLIB_SHA256_ISA_INTEL)
  return u32x4_byte_swap (r);
#elif defined(CLIB_SHA256_ISA_ARM)
  return vreinterpretq_u32_u8 (vrev32q_u8 (vreinterpretq_u8_u32 (r)));
#endif
}

static inline void
clib_sha256_vec_shuffle (u32x4 d[2])
{
#if defined(CLIB_SHA256_ISA_INTEL)
  /* {0, 1, 2, 3}, {4, 5, 6, 7} -> {7, 6, 3, 2}, {5, 4, 1, 0} */
  u32x4 r;
  r = (u32x4) _mm_shuffle_ps ((__m128) d[1], (__m128) d[0], 0xbb);
  d[1] = (u32x4) _mm_shuffle_ps ((__m128) d[1], (__m128) d[0], 0x11);
  d[0] = r;
#endif
}
#endif

static inline void
clib_sha256_block (clib_sha2_state_t *st, const u8 *msg, uword n_blocks)
{
#if defined(CLIB_SHA256_ISA)
  u32x4 h[2];
  u32x4u *m = (u32x4u *) msg;

  h[0] = st->h.h32x4[0];
  h[1] = st->h.h32x4[1];

  clib_sha256_vec_shuffle (h);

  for (; n_blocks; m += 4, n_blocks--)
    {
      u32x4 s[2], w[4];

      s[0] = h[0];
      s[1] = h[1];

      w[0] = clib_sha256_vec_load (m[0]);
      w[1] = clib_sha256_vec_load (m[1]);
      w[2] = clib_sha256_vec_load (m[2]);
      w[3] = clib_sha256_vec_load (m[3]);

      clib_sha256_vec_4_rounds (w[0], 0, s);
      clib_sha256_vec_4_rounds (w[1], 1, s);
      clib_sha256_vec_4_rounds (w[2], 2, s);
      clib_sha256_vec_4_rounds (w[3], 3, s);

      clib_sha256_vec_cycle_w (w, 0);
      clib_sha256_vec_4_rounds (w[0], 4, s);
      clib_sha256_vec_cycle_w (w, 1);
      clib_sha256_vec_4_rounds (w[1], 5, s);
      clib_sha256_vec_cycle_w (w, 2);
      clib_sha256_vec_4_rounds (w[2], 6, s);
      clib_sha256_vec_cycle_w (w, 3);
      clib_sha256_vec_4_rounds (w[3], 7, s);

      clib_sha256_vec_cycle_w (w, 0);
      clib_sha256_vec_4_rounds (w[0], 8, s);
      clib_sha256_vec_cycle_w (w, 1);
      clib_sha256_vec_4_rounds (w[1], 9, s);
      clib_sha256_vec_cycle_w (w, 2);
      clib_sha256_vec_4_rounds (w[2], 10, s);
      clib_sha256_vec_cycle_w (w, 3);
      clib_sha256_vec_4_rounds (w[3], 11, s);

      clib_sha256_vec_cycle_w (w, 0);
      clib_sha256_vec_4_rounds (w[0], 12, s);
      clib_sha256_vec_cycle_w (w, 1);
      clib_sha256_vec_4_rounds (w[1], 13, s);
      clib_sha256_vec_cycle_w (w, 2);
      clib_sha256_vec_4_rounds (w[2], 14, s);
      clib_sha256_vec_cycle_w (w, 3);
      clib_sha256_vec_4_rounds (w[3], 15, s);

      h[0] += s[0];
      h[1] += s[1];
    }

  clib_sha256_vec_shuffle (h);

  st->h.h32x4[0] = h[0];
  st->h.h32x4[1] = h[1];
#else
  u32 w[64], s[8], i;
  clib_sha2_h_t h;

  h = st->h;

  for (; n_blocks; msg += CLIB_SHA2_256_BLOCK_SIZE, n_blocks--)
    {
      for (i = 0; i < 8; i++)
	s[i] = h.h32[i];

      for (i = 0; i < 16; i++)
	{
	  w[i] = clib_net_to_host_u32 ((((u32u *) msg)[i]));
	  SHA256_TRANSFORM (s, w, i, clib_sha2_256_k[i]);
	}

      for (i = 16; i < 64; i++)
	{
	  SHA256_MSG_SCHED (w, i);
	  SHA256_TRANSFORM (s, w, i, clib_sha2_256_k[i]);
	}

      for (i = 0; i < 8; i++)
	h.h32[i] += s[i];
    }

  st->h = h;
#endif
}

static_always_inline void
clib_sha512_block (clib_sha2_state_t *st, const u8 *msg, uword n_blocks)
{
  u64 w[80], s[8], i;
  clib_sha2_h_t h;

  h = st->h;

  for (; n_blocks; msg += CLIB_SHA2_512_BLOCK_SIZE, n_blocks--)
    {
      for (i = 0; i < 8; i++)
	s[i] = h.h64[i];

      for (i = 0; i < 16; i++)
	{
	  w[i] = clib_net_to_host_u64 ((((u64u *) msg)[i]));
	  SHA512_TRANSFORM (s, w, i, clib_sha2_512_k[i]);
	}

      for (i = 16; i < 80; i++)
	{
	  SHA512_MSG_SCHED (w, i);
	  SHA512_TRANSFORM (s, w, i, clib_sha2_512_k[i]);
	}

      for (i = 0; i < 8; i++)
	h.h64[i] += s[i];
    }

  st->h = h;
}

static_always_inline void
clib_sha2_update_internal (clib_sha2_state_t *st, u8 block_size, const u8 *msg,
			   uword n_bytes)
{
  uword n_blocks;
  if (st->n_pending)
    {
      uword n_left = block_size - st->n_pending;
      if (n_bytes < n_left)
	{
	  clib_memcpy_fast (st->pending.as_u8 + st->n_pending, msg, n_bytes);
	  st->n_pending += n_bytes;
	  return;
	}
      else
	{
	  clib_memcpy_fast (st->pending.as_u8 + st->n_pending, msg, n_left);
	  if (block_size == CLIB_SHA2_512_BLOCK_SIZE)
	    clib_sha512_block (st, st->pending.as_u8, 1);
	  else
	    clib_sha256_block (st, st->pending.as_u8, 1);
	  st->n_pending = 0;
	  st->total_bytes += block_size;
	  n_bytes -= n_left;
	  msg += n_left;
	}
    }

  if ((n_blocks = n_bytes / block_size))
    {
      if (block_size == CLIB_SHA2_512_BLOCK_SIZE)
	clib_sha512_block (st, msg, n_blocks);
      else
	clib_sha256_block (st, msg, n_blocks);
      n_bytes -= n_blocks * block_size;
      msg += n_blocks * block_size;
      st->total_bytes += n_blocks * block_size;
    }

  if (n_bytes)
    {
      clib_memset_u8 (st->pending.as_u8, 0, block_size);
      clib_memcpy_fast (st->pending.as_u8, msg, n_bytes);
      st->n_pending = n_bytes;
    }
  else
    st->n_pending = 0;
}

static_always_inline void
clib_sha2_update (clib_sha2_ctx_t *ctx, const u8 *msg, uword n_bytes)
{
  clib_sha2_update_internal (&ctx->state, ctx->block_size, msg, n_bytes);
}

static_always_inline void
clib_sha2_final_internal (clib_sha2_state_t *st, u8 block_size, u8 digest_size,
			  u8 *digest)
{
  int i;

  st->total_bytes += st->n_pending;
  if (st->n_pending == 0)
    {
      clib_memset (st->pending.as_u8, 0, block_size);
      st->pending.as_u8[0] = 0x80;
    }
  else if (st->n_pending + sizeof (u64) + sizeof (u8) > block_size)
    {
      st->pending.as_u8[st->n_pending] = 0x80;
      if (block_size == CLIB_SHA2_512_BLOCK_SIZE)
	clib_sha512_block (st, st->pending.as_u8, 1);
      else
	clib_sha256_block (st, st->pending.as_u8, 1);
      clib_memset (st->pending.as_u8, 0, block_size);
    }
  else
    st->pending.as_u8[st->n_pending] = 0x80;

  st->pending.as_u64[block_size / 8 - 1] =
    clib_net_to_host_u64 (st->total_bytes * 8);

  if (block_size == CLIB_SHA2_512_BLOCK_SIZE)
    {
      clib_sha512_block (st, st->pending.as_u8, 1);
      for (i = 0; i < digest_size / sizeof (u64); i++)
	((u64 *) digest)[i] = clib_net_to_host_u64 (st->h.h64[i]);

      /* sha512-224 case - write half of u64 */
      if (i * sizeof (u64) < digest_size)
	((u32 *) digest)[2 * i] = clib_net_to_host_u32 (st->h.h64[i] >> 32);
    }
  else
    {
      clib_sha256_block (st, st->pending.as_u8, 1);
      for (i = 0; i < digest_size / sizeof (u32); i++)
	*((u32 *) digest + i) = clib_net_to_host_u32 (st->h.h32[i]);
    }
}

static_always_inline void
clib_sha2_final (clib_sha2_ctx_t *ctx, u8 *digest)
{
  clib_sha2_final_internal (&ctx->state, ctx->block_size, ctx->digest_size,
			    digest);
}

static_always_inline void
clib_sha2 (clib_sha2_type_t type, const u8 *msg, uword len, u8 *digest)
{
  clib_sha2_ctx_t ctx;
  clib_sha2_init (&ctx, type);
  clib_sha2_update (&ctx, msg, len);
  clib_sha2_final (&ctx, digest);
}

#define clib_sha224(...)     clib_sha2 (CLIB_SHA2_224, __VA_ARGS__)
#define clib_sha256(...)     clib_sha2 (CLIB_SHA2_256, __VA_ARGS__)
#define clib_sha384(...)     clib_sha2 (CLIB_SHA2_384, __VA_ARGS__)
#define clib_sha512(...)     clib_sha2 (CLIB_SHA2_512, __VA_ARGS__)
#define clib_sha512_224(...) clib_sha2 (CLIB_SHA2_512_224, __VA_ARGS__)
#define clib_sha512_256(...) clib_sha2 (CLIB_SHA2_512_256, __VA_ARGS__)

/*
 *  HMAC
 */

typedef struct
{
  clib_sha2_h_t ipad_h;
  clib_sha2_h_t opad_h;
} clib_sha2_hmac_key_data_t;

typedef struct
{
  clib_sha2_type_t type;
  u8 block_size;
  u8 digest_size;
  clib_sha2_state_t ipad_state;
  clib_sha2_state_t opad_state;
} clib_sha2_hmac_ctx_t;

static_always_inline void
clib_sha2_hmac_key_data (clib_sha2_type_t type, const u8 *key, uword key_len,
			 clib_sha2_hmac_key_data_t *kd)
{
  u8 block_size = clib_sha2_variants[type].block_size;
  u8 data[SHA2_MAX_BLOCK_SIZE] = {};
  u8 ikey[SHA2_MAX_BLOCK_SIZE];
  u8 okey[SHA2_MAX_BLOCK_SIZE];
  clib_sha2_state_t ipad_state;
  clib_sha2_state_t opad_state;

  /* key */
  if (key_len > block_size)
    {
      /* key is longer than block, calculate hash of key */
      clib_sha2_ctx_t ctx;
      clib_sha2_init (&ctx, type);
      clib_sha2_update (&ctx, key, key_len);
      clib_sha2_final (&ctx, (u8 *) data);
    }
  else
    clib_memcpy_fast (data, key, key_len);

  for (int i = 0, w = 0; w < block_size; w += sizeof (uword), i++)
    {
      ((uwordu *) ikey)[i] = ((uwordu *) data)[i] ^ 0x3636363636363636UL;
      ((uwordu *) okey)[i] = ((uwordu *) data)[i] ^ 0x5c5c5c5c5c5c5c5cUL;
    }

  clib_sha2_state_init (&ipad_state, type);
  clib_sha2_state_init (&opad_state, type);

  if (block_size == CLIB_SHA2_512_BLOCK_SIZE)
    {
      clib_sha512_block (&ipad_state, ikey, 1);
      clib_sha512_block (&opad_state, okey, 1);
    }
  else
    {
      clib_sha256_block (&ipad_state, ikey, 1);
      clib_sha256_block (&opad_state, okey, 1);
    }

  kd->ipad_h = ipad_state.h;
  kd->opad_h = opad_state.h;
}

static_always_inline void
clib_sha2_hmac_init (clib_sha2_hmac_ctx_t *ctx, clib_sha2_type_t type,
		     clib_sha2_hmac_key_data_t *kd)
{
  u8 block_size = clib_sha2_variants[type].block_size;
  u8 digest_size = clib_sha2_variants[type].digest_size;

  *ctx = (clib_sha2_hmac_ctx_t) {
    .type = type,
    .block_size = block_size,
    .digest_size = digest_size,
    .ipad_state = {
      .h = kd->ipad_h,
      .total_bytes = block_size,
    },
    .opad_state = {
      .h = kd->opad_h,
      .total_bytes = block_size,
    },
  };
}

static_always_inline void
clib_sha2_hmac_update (clib_sha2_hmac_ctx_t *ctx, const u8 *msg, uword len)
{
  clib_sha2_update_internal (&ctx->ipad_state, ctx->block_size, msg, len);
}

static_always_inline void
clib_sha2_hmac_final (clib_sha2_hmac_ctx_t *ctx, u8 *digest)
{
  u8 i_digest[SHA2_MAX_DIGEST_SIZE];

  clib_sha2_final_internal (&ctx->ipad_state, ctx->block_size,
			    ctx->digest_size, i_digest);
  clib_sha2_update_internal (&ctx->opad_state, ctx->block_size, i_digest,
			     ctx->digest_size);
  clib_sha2_final_internal (&ctx->opad_state, ctx->block_size,
			    ctx->digest_size, digest);
}

static_always_inline void
clib_sha2_hmac (clib_sha2_type_t type, const u8 *key, uword key_len,
		const u8 *msg, uword len, u8 *digest)
{
  clib_sha2_hmac_ctx_t _ctx, *ctx = &_ctx;
  clib_sha2_hmac_key_data_t kd;

  clib_sha2_hmac_key_data (type, key, key_len, &kd);
  clib_sha2_hmac_init (ctx, type, &kd);
  clib_sha2_hmac_update (ctx, msg, len);
  clib_sha2_hmac_final (ctx, digest);
}

#define clib_hmac_sha224(...) clib_sha2_hmac (CLIB_SHA2_224, __VA_ARGS__)
#define clib_hmac_sha256(...) clib_sha2_hmac (CLIB_SHA2_256, __VA_ARGS__)
#define clib_hmac_sha384(...) clib_sha2_hmac (CLIB_SHA2_384, __VA_ARGS__)
#define clib_hmac_sha512(...) clib_sha2_hmac (CLIB_SHA2_512, __VA_ARGS__)
#define clib_hmac_sha512_224(...)                                             \
  clib_sha2_hmac (CLIB_SHA2_512_224, __VA_ARGS__)
#define clib_hmac_sha512_256(...)                                             \
  clib_sha2_hmac (CLIB_SHA2_512_256, __VA_ARGS__)

#endif /* included_sha2_h */