crypto/poly1305/poly1305.c - boringssl - Git at Google

 /* Copyright (c) 2014, Google Inc.
  *
  * Permission to use, copy, modify, and/or distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
  * copyright notice and this permission notice appear in all copies.
  *
  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
  * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
  * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
  * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */

 /* This implementation of poly1305 is by Andrew Moon
  * (https://github.com/floodyberry/poly1305-donna) and released as public
  * domain. */

 #include <openssl/poly1305.h>

 #include <string.h>

 #include <openssl/cpu.h>


 #if defined(OPENSSL_WINDOWS) || !defined(OPENSSL_X86_64)

 #if defined(OPENSSL_X86) || defined(OPENSSL_X86_64) || defined(OPENSSL_ARM)
 /* We can assume little-endian. */
 static uint32_t U8TO32_LE(const uint8_t *m) {
   uint32_t r;
   memcpy(&r, m, sizeof(r));
   return r;
 }

 static void U32TO8_LE(uint8_t *m, uint32_t v) { memcpy(m, &v, sizeof(v)); }
 #else
 static uint32_t U8TO32_LE(const uint8_t *m) {
   return (uint32_t)m[0] | (uint32_t)m[1] << 8 | (uint32_t)m[2] << 16 |
          (uint32_t)m[3] << 24;
 }

 static void U32TO8_LE(uint8_t *m, uint32_t v) {
   m[0] = v;
   m[1] = v >> 8;
   m[2] = v >> 16;
   m[3] = v >> 24;
 }
 #endif

 #if defined(OPENSSL_ARM) && !defined(OPENSSL_NO_ASM)
 void CRYPTO_poly1305_init_neon(poly1305_state *state, const uint8_t key[32]);

 void CRYPTO_poly1305_update_neon(poly1305_state *state, const uint8_t *in,
                                  size_t in_len);

 void CRYPTO_poly1305_finish_neon(poly1305_state *state, uint8_t mac[16]);
 #endif

 static uint64_t mul32x32_64(uint32_t a, uint32_t b) { return (uint64_t)a * b; }

 struct poly1305_state_st {
   uint32_t r0, r1, r2, r3, r4;
   uint32_t s1, s2, s3, s4;
   uint32_t h0, h1, h2, h3, h4;
   uint8_t buf[16];
   unsigned int buf_used;
   uint8_t key[16];
 };

 /* poly1305_blocks updates |state| given some amount of input data. This
  * function may only be called with a |len| that is not a multiple of 16 at the
  * end of the data. Otherwise the input must be buffered into 16 byte blocks. */
 static void poly1305_update(struct poly1305_state_st *state, const uint8_t *in,
                             size_t len) {
   uint32_t t0, t1, t2, t3;
   uint64_t t[5];
   uint32_t b;
   uint64_t c;
   size_t j;
   uint8_t mp[16];

   if (len < 16) {
     goto poly1305_donna_atmost15bytes;
   }

 poly1305_donna_16bytes:
   t0 = U8TO32_LE(in);
   t1 = U8TO32_LE(in + 4);
   t2 = U8TO32_LE(in + 8);
   t3 = U8TO32_LE(in + 12);

   in += 16;
   len -= 16;

   state->h0 += t0 & 0x3ffffff;
   state->h1 += ((((uint64_t)t1 << 32) | t0) >> 26) & 0x3ffffff;
   state->h2 += ((((uint64_t)t2 << 32) | t1) >> 20) & 0x3ffffff;
   state->h3 += ((((uint64_t)t3 << 32) | t2) >> 14) & 0x3ffffff;
   state->h4 += (t3 >> 8) | (1 << 24);

 poly1305_donna_mul:
   t[0] = mul32x32_64(state->h0, state->r0) + mul32x32_64(state->h1, state->s4) +
          mul32x32_64(state->h2, state->s3) + mul32x32_64(state->h3, state->s2) +
          mul32x32_64(state->h4, state->s1);
   t[1] = mul32x32_64(state->h0, state->r1) + mul32x32_64(state->h1, state->r0) +
          mul32x32_64(state->h2, state->s4) + mul32x32_64(state->h3, state->s3) +
          mul32x32_64(state->h4, state->s2);
   t[2] = mul32x32_64(state->h0, state->r2) + mul32x32_64(state->h1, state->r1) +
          mul32x32_64(state->h2, state->r0) + mul32x32_64(state->h3, state->s4) +
          mul32x32_64(state->h4, state->s3);
   t[3] = mul32x32_64(state->h0, state->r3) + mul32x32_64(state->h1, state->r2) +
          mul32x32_64(state->h2, state->r1) + mul32x32_64(state->h3, state->r0) +
          mul32x32_64(state->h4, state->s4);
   t[4] = mul32x32_64(state->h0, state->r4) + mul32x32_64(state->h1, state->r3) +
          mul32x32_64(state->h2, state->r2) + mul32x32_64(state->h3, state->r1) +
          mul32x32_64(state->h4, state->r0);

   state->h0 = (uint32_t)t[0] & 0x3ffffff;
   c = (t[0] >> 26);
   t[1] += c;
   state->h1 = (uint32_t)t[1] & 0x3ffffff;
   b = (uint32_t)(t[1] >> 26);
   t[2] += b;
   state->h2 = (uint32_t)t[2] & 0x3ffffff;
   b = (uint32_t)(t[2] >> 26);
   t[3] += b;
   state->h3 = (uint32_t)t[3] & 0x3ffffff;
   b = (uint32_t)(t[3] >> 26);
   t[4] += b;
   state->h4 = (uint32_t)t[4] & 0x3ffffff;
   b = (uint32_t)(t[4] >> 26);
   state->h0 += b * 5;

   if (len >= 16) {
     goto poly1305_donna_16bytes;
   }

 /* final bytes */
 poly1305_donna_atmost15bytes:
   if (!len) {
     return;
   }

   for (j = 0; j < len; j++) {
     mp[j] = in[j];
   }
   mp[j++] = 1;
   for (; j < 16; j++) {
     mp[j] = 0;
   }
   len = 0;

   t0 = U8TO32_LE(mp + 0);
   t1 = U8TO32_LE(mp + 4);
   t2 = U8TO32_LE(mp + 8);
   t3 = U8TO32_LE(mp + 12);

   state->h0 += t0 & 0x3ffffff;
   state->h1 += ((((uint64_t)t1 << 32) | t0) >> 26) & 0x3ffffff;
   state->h2 += ((((uint64_t)t2 << 32) | t1) >> 20) & 0x3ffffff;
   state->h3 += ((((uint64_t)t3 << 32) | t2) >> 14) & 0x3ffffff;
   state->h4 += (t3 >> 8);

   goto poly1305_donna_mul;
 }

 void CRYPTO_poly1305_init(poly1305_state *statep, const uint8_t key[32]) {
   struct poly1305_state_st *state = (struct poly1305_state_st *)statep;
   uint32_t t0, t1, t2, t3;

 #if defined(OPENSSL_ARM) && !defined(OPENSSL_NO_ASM)
   if (CRYPTO_is_NEON_functional()) {
     CRYPTO_poly1305_init_neon(statep, key);
     return;
   }
 #endif

   t0 = U8TO32_LE(key + 0);
   t1 = U8TO32_LE(key + 4);
   t2 = U8TO32_LE(key + 8);
   t3 = U8TO32_LE(key + 12);

   /* precompute multipliers */
   state->r0 = t0 & 0x3ffffff;
   t0 >>= 26;
   t0 |= t1 << 6;
   state->r1 = t0 & 0x3ffff03;
   t1 >>= 20;
   t1 |= t2 << 12;
   state->r2 = t1 & 0x3ffc0ff;
   t2 >>= 14;
   t2 |= t3 << 18;
   state->r3 = t2 & 0x3f03fff;
   t3 >>= 8;
   state->r4 = t3 & 0x00fffff;

   state->s1 = state->r1 * 5;
   state->s2 = state->r2 * 5;
   state->s3 = state->r3 * 5;
   state->s4 = state->r4 * 5;

   /* init state */
   state->h0 = 0;
   state->h1 = 0;
   state->h2 = 0;
   state->h3 = 0;
   state->h4 = 0;

   state->buf_used = 0;
   memcpy(state->key, key + 16, sizeof(state->key));
 }

 void CRYPTO_poly1305_update(poly1305_state *statep, const uint8_t *in,
                             size_t in_len) {
   unsigned int i;
   struct poly1305_state_st *state = (struct poly1305_state_st *)statep;

 #if defined(OPENSSL_ARM) && !defined(OPENSSL_NO_ASM)
   if (CRYPTO_is_NEON_functional()) {
     CRYPTO_poly1305_update_neon(statep, in, in_len);
     return;
   }
 #endif

   if (state->buf_used) {
     unsigned int todo = 16 - state->buf_used;
     if (todo > in_len) {
       todo = in_len;
     }
     for (i = 0; i < todo; i++) {
       state->buf[state->buf_used + i] = in[i];
     }
     state->buf_used += todo;
     in_len -= todo;
     in += todo;

     if (state->buf_used == 16) {
       poly1305_update(state, state->buf, 16);
       state->buf_used = 0;
     }
   }

   if (in_len >= 16) {
     size_t todo = in_len & ~0xf;
     poly1305_update(state, in, todo);
     in += todo;
     in_len &= 0xf;
   }

   if (in_len) {
     for (i = 0; i < in_len; i++) {
       state->buf[i] = in[i];
     }
     state->buf_used = in_len;
   }
 }

 void CRYPTO_poly1305_finish(poly1305_state *statep, uint8_t mac[16]) {
   struct poly1305_state_st *state = (struct poly1305_state_st *)statep;
   uint64_t f0, f1, f2, f3;
   uint32_t g0, g1, g2, g3, g4;
   uint32_t b, nb;

 #if defined(OPENSSL_ARM) && !defined(OPENSSL_NO_ASM)
   if (CRYPTO_is_NEON_functional()) {
     CRYPTO_poly1305_finish_neon(statep, mac);
     return;
   }
 #endif

   if (state->buf_used) {
     poly1305_update(state, state->buf, state->buf_used);
   }

   b = state->h0 >> 26;
   state->h0 = state->h0 & 0x3ffffff;
   state->h1 += b;
   b = state->h1 >> 26;
   state->h1 = state->h1 & 0x3ffffff;
   state->h2 += b;
   b = state->h2 >> 26;
   state->h2 = state->h2 & 0x3ffffff;
   state->h3 += b;
   b = state->h3 >> 26;
   state->h3 = state->h3 & 0x3ffffff;
   state->h4 += b;
   b = state->h4 >> 26;
   state->h4 = state->h4 & 0x3ffffff;
   state->h0 += b * 5;

   g0 = state->h0 + 5;
   b = g0 >> 26;
   g0 &= 0x3ffffff;
   g1 = state->h1 + b;
   b = g1 >> 26;
   g1 &= 0x3ffffff;
   g2 = state->h2 + b;
   b = g2 >> 26;
   g2 &= 0x3ffffff;
   g3 = state->h3 + b;
   b = g3 >> 26;
   g3 &= 0x3ffffff;
   g4 = state->h4 + b - (1 << 26);

   b = (g4 >> 31) - 1;
   nb = ~b;
   state->h0 = (state->h0 & nb) | (g0 & b);
   state->h1 = (state->h1 & nb) | (g1 & b);
   state->h2 = (state->h2 & nb) | (g2 & b);
   state->h3 = (state->h3 & nb) | (g3 & b);
   state->h4 = (state->h4 & nb) | (g4 & b);

   f0 = ((state->h0) | (state->h1 << 26)) + (uint64_t)U8TO32_LE(&state->key[0]);
   f1 = ((state->h1 >> 6) | (state->h2 << 20)) +
        (uint64_t)U8TO32_LE(&state->key[4]);
   f2 = ((state->h2 >> 12) | (state->h3 << 14)) +
        (uint64_t)U8TO32_LE(&state->key[8]);
   f3 = ((state->h3 >> 18) | (state->h4 << 8)) +
        (uint64_t)U8TO32_LE(&state->key[12]);

   U32TO8_LE(&mac[0], f0);
   f1 += (f0 >> 32);
   U32TO8_LE(&mac[4], f1);
   f2 += (f1 >> 32);
   U32TO8_LE(&mac[8], f2);
   f3 += (f2 >> 32);
   U32TO8_LE(&mac[12], f3);
 }

 #endif  /* OPENSSL_WINDOWS || !OPENSSL_X86_64 */
	/* Copyright (c) 2014, Google Inc.
	*
	* Permission to use, copy, modify, and/or distribute this software for any
	* purpose with or without fee is hereby granted, provided that the above
	* copyright notice and this permission notice appear in all copies.
	*
	* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
	* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
	* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
	* SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
	* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
	* OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
	* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */

	/* This implementation of poly1305 is by Andrew Moon
	* (https://github.com/floodyberry/poly1305-donna) and released as public
	* domain. */

	#include <openssl/poly1305.h>

	#include <string.h>

	#include <openssl/cpu.h>


	#if defined(OPENSSL_WINDOWS) \|\| !defined(OPENSSL_X86_64)

	#if defined(OPENSSL_X86) \|\| defined(OPENSSL_X86_64) \|\| defined(OPENSSL_ARM)
	/* We can assume little-endian. */
	static uint32_t U8TO32_LE(const uint8_t *m) {
	uint32_t r;
	memcpy(&r, m, sizeof(r));
	return r;
	}

	static void U32TO8_LE(uint8_t *m, uint32_t v) { memcpy(m, &v, sizeof(v)); }
	#else
	static uint32_t U8TO32_LE(const uint8_t *m) {
	return (uint32_t)m[0] \| (uint32_t)m[1] << 8 \| (uint32_t)m[2] << 16 \|
	(uint32_t)m[3] << 24;
	}

	static void U32TO8_LE(uint8_t *m, uint32_t v) {
	m[0] = v;
	m[1] = v >> 8;
	m[2] = v >> 16;
	m[3] = v >> 24;
	}
	#endif

	#if defined(OPENSSL_ARM) && !defined(OPENSSL_NO_ASM)
	void CRYPTO_poly1305_init_neon(poly1305_state *state, const uint8_t key[32]);

	void CRYPTO_poly1305_update_neon(poly1305_state state, const uint8_t in,
	size_t in_len);

	void CRYPTO_poly1305_finish_neon(poly1305_state *state, uint8_t mac[16]);
	#endif

	static uint64_t mul32x32_64(uint32_t a, uint32_t b) { return (uint64_t)a * b; }

	struct poly1305_state_st {
	uint32_t r0, r1, r2, r3, r4;
	uint32_t s1, s2, s3, s4;
	uint32_t h0, h1, h2, h3, h4;
	uint8_t buf[16];
	unsigned int buf_used;
	uint8_t key[16];
	};

	/* poly1305_blocks updates \|state\| given some amount of input data. This
	* function may only be called with a \|len\| that is not a multiple of 16 at the
	* end of the data. Otherwise the input must be buffered into 16 byte blocks. */
	static void poly1305_update(struct poly1305_state_st state, const uint8_t in,
	size_t len) {
	uint32_t t0, t1, t2, t3;
	uint64_t t[5];
	uint32_t b;
	uint64_t c;
	size_t j;
	uint8_t mp[16];

	if (len < 16) {
	goto poly1305_donna_atmost15bytes;
	}

	poly1305_donna_16bytes:
	t0 = U8TO32_LE(in);
	t1 = U8TO32_LE(in + 4);
	t2 = U8TO32_LE(in + 8);
	t3 = U8TO32_LE(in + 12);

	in += 16;
	len -= 16;

	state->h0 += t0 & 0x3ffffff;
	state->h1 += ((((uint64_t)t1 << 32) \| t0) >> 26) & 0x3ffffff;
	state->h2 += ((((uint64_t)t2 << 32) \| t1) >> 20) & 0x3ffffff;
	state->h3 += ((((uint64_t)t3 << 32) \| t2) >> 14) & 0x3ffffff;
	state->h4 += (t3 >> 8) \| (1 << 24);

	poly1305_donna_mul:
	t[0] = mul32x32_64(state->h0, state->r0) + mul32x32_64(state->h1, state->s4) +
	mul32x32_64(state->h2, state->s3) + mul32x32_64(state->h3, state->s2) +
	mul32x32_64(state->h4, state->s1);
	t[1] = mul32x32_64(state->h0, state->r1) + mul32x32_64(state->h1, state->r0) +
	mul32x32_64(state->h2, state->s4) + mul32x32_64(state->h3, state->s3) +
	mul32x32_64(state->h4, state->s2);
	t[2] = mul32x32_64(state->h0, state->r2) + mul32x32_64(state->h1, state->r1) +
	mul32x32_64(state->h2, state->r0) + mul32x32_64(state->h3, state->s4) +
	mul32x32_64(state->h4, state->s3);
	t[3] = mul32x32_64(state->h0, state->r3) + mul32x32_64(state->h1, state->r2) +
	mul32x32_64(state->h2, state->r1) + mul32x32_64(state->h3, state->r0) +
	mul32x32_64(state->h4, state->s4);
	t[4] = mul32x32_64(state->h0, state->r4) + mul32x32_64(state->h1, state->r3) +
	mul32x32_64(state->h2, state->r2) + mul32x32_64(state->h3, state->r1) +
	mul32x32_64(state->h4, state->r0);

	state->h0 = (uint32_t)t[0] & 0x3ffffff;
	c = (t[0] >> 26);
	t[1] += c;
	state->h1 = (uint32_t)t[1] & 0x3ffffff;
	b = (uint32_t)(t[1] >> 26);
	t[2] += b;
	state->h2 = (uint32_t)t[2] & 0x3ffffff;
	b = (uint32_t)(t[2] >> 26);
	t[3] += b;
	state->h3 = (uint32_t)t[3] & 0x3ffffff;
	b = (uint32_t)(t[3] >> 26);
	t[4] += b;
	state->h4 = (uint32_t)t[4] & 0x3ffffff;
	b = (uint32_t)(t[4] >> 26);
	state->h0 += b * 5;

	if (len >= 16) {
	goto poly1305_donna_16bytes;
	}

	/* final bytes */
	poly1305_donna_atmost15bytes:
	if (!len) {
	return;
	}

	for (j = 0; j < len; j++) {
	mp[j] = in[j];
	}
	mp[j++] = 1;
	for (; j < 16; j++) {
	mp[j] = 0;
	}
	len = 0;

	t0 = U8TO32_LE(mp + 0);
	t1 = U8TO32_LE(mp + 4);
	t2 = U8TO32_LE(mp + 8);
	t3 = U8TO32_LE(mp + 12);

	state->h0 += t0 & 0x3ffffff;
	state->h1 += ((((uint64_t)t1 << 32) \| t0) >> 26) & 0x3ffffff;
	state->h2 += ((((uint64_t)t2 << 32) \| t1) >> 20) & 0x3ffffff;
	state->h3 += ((((uint64_t)t3 << 32) \| t2) >> 14) & 0x3ffffff;
	state->h4 += (t3 >> 8);

	goto poly1305_donna_mul;
	}

	void CRYPTO_poly1305_init(poly1305_state *statep, const uint8_t key[32]) {
	struct poly1305_state_st state = (struct poly1305_state_st )statep;
	uint32_t t0, t1, t2, t3;

	#if defined(OPENSSL_ARM) && !defined(OPENSSL_NO_ASM)
	if (CRYPTO_is_NEON_functional()) {
	CRYPTO_poly1305_init_neon(statep, key);
	return;
	}
	#endif

	t0 = U8TO32_LE(key + 0);
	t1 = U8TO32_LE(key + 4);
	t2 = U8TO32_LE(key + 8);
	t3 = U8TO32_LE(key + 12);

	/* precompute multipliers */
	state->r0 = t0 & 0x3ffffff;
	t0 >>= 26;
	t0 \|= t1 << 6;
	state->r1 = t0 & 0x3ffff03;
	t1 >>= 20;
	t1 \|= t2 << 12;
	state->r2 = t1 & 0x3ffc0ff;
	t2 >>= 14;
	t2 \|= t3 << 18;
	state->r3 = t2 & 0x3f03fff;
	t3 >>= 8;
	state->r4 = t3 & 0x00fffff;

	state->s1 = state->r1 * 5;
	state->s2 = state->r2 * 5;
	state->s3 = state->r3 * 5;
	state->s4 = state->r4 * 5;

	/* init state */
	state->h0 = 0;
	state->h1 = 0;
	state->h2 = 0;
	state->h3 = 0;
	state->h4 = 0;

	state->buf_used = 0;
	memcpy(state->key, key + 16, sizeof(state->key));
	}

	void CRYPTO_poly1305_update(poly1305_state statep, const uint8_t in,
	size_t in_len) {
	unsigned int i;
	struct poly1305_state_st state = (struct poly1305_state_st )statep;

	#if defined(OPENSSL_ARM) && !defined(OPENSSL_NO_ASM)
	if (CRYPTO_is_NEON_functional()) {
	CRYPTO_poly1305_update_neon(statep, in, in_len);
	return;
	}
	#endif

	if (state->buf_used) {
	unsigned int todo = 16 - state->buf_used;
	if (todo > in_len) {
	todo = in_len;
	}
	for (i = 0; i < todo; i++) {
	state->buf[state->buf_used + i] = in[i];
	}
	state->buf_used += todo;
	in_len -= todo;
	in += todo;

	if (state->buf_used == 16) {
	poly1305_update(state, state->buf, 16);
	state->buf_used = 0;
	}
	}

	if (in_len >= 16) {
	size_t todo = in_len & ~0xf;
	poly1305_update(state, in, todo);
	in += todo;
	in_len &= 0xf;
	}

	if (in_len) {
	for (i = 0; i < in_len; i++) {
	state->buf[i] = in[i];
	}
	state->buf_used = in_len;
	}
	}

	void CRYPTO_poly1305_finish(poly1305_state *statep, uint8_t mac[16]) {
	struct poly1305_state_st state = (struct poly1305_state_st )statep;
	uint64_t f0, f1, f2, f3;
	uint32_t g0, g1, g2, g3, g4;
	uint32_t b, nb;

	#if defined(OPENSSL_ARM) && !defined(OPENSSL_NO_ASM)
	if (CRYPTO_is_NEON_functional()) {
	CRYPTO_poly1305_finish_neon(statep, mac);
	return;
	}
	#endif

	if (state->buf_used) {
	poly1305_update(state, state->buf, state->buf_used);
	}

	b = state->h0 >> 26;
	state->h0 = state->h0 & 0x3ffffff;
	state->h1 += b;
	b = state->h1 >> 26;
	state->h1 = state->h1 & 0x3ffffff;
	state->h2 += b;
	b = state->h2 >> 26;
	state->h2 = state->h2 & 0x3ffffff;
	state->h3 += b;
	b = state->h3 >> 26;
	state->h3 = state->h3 & 0x3ffffff;
	state->h4 += b;
	b = state->h4 >> 26;
	state->h4 = state->h4 & 0x3ffffff;
	state->h0 += b * 5;

	g0 = state->h0 + 5;
	b = g0 >> 26;
	g0 &= 0x3ffffff;
	g1 = state->h1 + b;
	b = g1 >> 26;
	g1 &= 0x3ffffff;
	g2 = state->h2 + b;
	b = g2 >> 26;
	g2 &= 0x3ffffff;
	g3 = state->h3 + b;
	b = g3 >> 26;
	g3 &= 0x3ffffff;
	g4 = state->h4 + b - (1 << 26);

	b = (g4 >> 31) - 1;
	nb = ~b;
	state->h0 = (state->h0 & nb) \| (g0 & b);
	state->h1 = (state->h1 & nb) \| (g1 & b);
	state->h2 = (state->h2 & nb) \| (g2 & b);
	state->h3 = (state->h3 & nb) \| (g3 & b);
	state->h4 = (state->h4 & nb) \| (g4 & b);

	f0 = ((state->h0) \| (state->h1 << 26)) + (uint64_t)U8TO32_LE(&state->key[0]);
	f1 = ((state->h1 >> 6) \| (state->h2 << 20)) +
	(uint64_t)U8TO32_LE(&state->key[4]);
	f2 = ((state->h2 >> 12) \| (state->h3 << 14)) +
	(uint64_t)U8TO32_LE(&state->key[8]);
	f3 = ((state->h3 >> 18) \| (state->h4 << 8)) +
	(uint64_t)U8TO32_LE(&state->key[12]);

	U32TO8_LE(&mac[0], f0);
	f1 += (f0 >> 32);
	U32TO8_LE(&mac[4], f1);
	f2 += (f1 >> 32);
	U32TO8_LE(&mac[8], f2);
	f3 += (f2 >> 32);
	U32TO8_LE(&mac[12], f3);
	}

	#endif /* OPENSSL_WINDOWS \|\| !OPENSSL_X86_64 */