/*

 * No copyright is claimed.  This code is in the public domain; do with

 * it what you wish.

 *

 * SHA-1 in C by Steve Reid <steve@edmweb.com>

 * 100% Public Domain

 *

 * Test Vectors (from FIPS PUB 180-1)

 * 1) "abc": A9993E36 4706816A BA3E2571 7850C26C 9CD0D89D

 * 2) "abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq":  84983E44 1C3BD26E BAAE4AA1 F95129E5 E54670F1

 * 3) A million repetitions of "a":  34AA973C D4C4DAA4 F61EEB2B DBAD2731 6534016F

 */

#define UL_SHA1HANDSOFF

#include <stdio.h>

#include <string.h>

#include <stdint.h>

#include "sha1.h"

#define rol(value, bits) (((value) << (bits)) | ((value) >> (32 - (bits))))

/* blk0() and blk() perform the initial expand. */

#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__

# define blk0(i) block->l[i]

#else

# define blk0(i) (block->l[i] = (rol(block->l[i],24)&0xFF00FF00) \

    |(rol(block->l[i],8)&0x00FF00FF))

#endif

#define blk(i) (block->l[i&15] = rol(block->l[(i+13)&15]^block->l[(i+8)&15] \

    ^block->l[(i+2)&15]^block->l[i&15],1))

/* (R0+R1), R2, R3, R4 are the different operations used in SHA1 */

#define R0(v,w,x,y,z,i) z+=((w&(x^y))^y)+blk0(i)+0x5A827999+rol(v,5);w=rol(w,30);

#define R1(v,w,x,y,z,i) z+=((w&(x^y))^y)+blk(i)+0x5A827999+rol(v,5);w=rol(w,30);

#define R2(v,w,x,y,z,i) z+=(w^x^y)+blk(i)+0x6ED9EBA1+rol(v,5);w=rol(w,30);

#define R3(v,w,x,y,z,i) z+=(((w|x)&y)|(w&x))+blk(i)+0x8F1BBCDC+rol(v,5);w=rol(w,30);

#define R4(v,w,x,y,z,i) z+=(w^x^y)+blk(i)+0xCA62C1D6+rol(v,5);w=rol(w,30);

/* Hash a single 512-bit block. This is the core of the algorithm. */

void ul_SHA1Transform(uint32_t state[5], const unsigned char buffer[64])

{

  uint32_t a, b, c, d, e;

  typedef union {

    unsigned char c[64];

    uint32_t l[16];

  } CHAR64LONG16;

#ifdef UL_SHA1HANDSOFF

  CHAR64LONG16 block[1];  /* use array to appear as a pointer */

  memcpy(block, buffer, 64);

#else

  /* The following had better never be used because it causes the

   * pointer-to-const buffer to be cast into a pointer to non-const.

   * And the result is written through.  I threw a "const" in, hoping

   * this will cause a diagnostic.

   */

  CHAR64LONG16 *block = (const CHAR64LONG16 *)buffer;

#endif

  /* Copy context->state[] to working vars */

  a = state[0];

  b = state[1];

  c = state[2];

  d = state[3];

  e = state[4];

  /* 4 rounds of 20 operations each. Loop unrolled. */

  R0(a, b, c, d, e, 0);

  R0(e, a, b, c, d, 1);

  R0(d, e, a, b, c, 2);

  R0(c, d, e, a, b, 3);

  R0(b, c, d, e, a, 4);

  R0(a, b, c, d, e, 5);

  R0(e, a, b, c, d, 6);

  R0(d, e, a, b, c, 7);

  R0(c, d, e, a, b, 8);

  R0(b, c, d, e, a, 9);

  R0(a, b, c, d, e, 10);

  R0(e, a, b, c, d, 11);

  R0(d, e, a, b, c, 12);

  R0(c, d, e, a, b, 13);

  R0(b, c, d, e, a, 14);

  R0(a, b, c, d, e, 15);

  R1(e, a, b, c, d, 16);

  R1(d, e, a, b, c, 17);

  R1(c, d, e, a, b, 18);

  R1(b, c, d, e, a, 19);

  R2(a, b, c, d, e, 20);

  R2(e, a, b, c, d, 21);

  R2(d, e, a, b, c, 22);

  R2(c, d, e, a, b, 23);

  R2(b, c, d, e, a, 24);

  R2(a, b, c, d, e, 25);

  R2(e, a, b, c, d, 26);

  R2(d, e, a, b, c, 27);

  R2(c, d, e, a, b, 28);

  R2(b, c, d, e, a, 29);

  R2(a, b, c, d, e, 30);

  R2(e, a, b, c, d, 31);

  R2(d, e, a, b, c, 32);

  R2(c, d, e, a, b, 33);

  R2(b, c, d, e, a, 34);

  R2(a, b, c, d, e, 35);

  R2(e, a, b, c, d, 36);

  R2(d, e, a, b, c, 37);

  R2(c, d, e, a, b, 38);

  R2(b, c, d, e, a, 39);

  R3(a, b, c, d, e, 40);

  R3(e, a, b, c, d, 41);

  R3(d, e, a, b, c, 42);

  R3(c, d, e, a, b, 43);

  R3(b, c, d, e, a, 44);

  R3(a, b, c, d, e, 45);

  R3(e, a, b, c, d, 46);

  R3(d, e, a, b, c, 47);

  R3(c, d, e, a, b, 48);

  R3(b, c, d, e, a, 49);

  R3(a, b, c, d, e, 50);

  R3(e, a, b, c, d, 51);

  R3(d, e, a, b, c, 52);

  R3(c, d, e, a, b, 53);

  R3(b, c, d, e, a, 54);

  R3(a, b, c, d, e, 55);

  R3(e, a, b, c, d, 56);

  R3(d, e, a, b, c, 57);

  R3(c, d, e, a, b, 58);

  R3(b, c, d, e, a, 59);

  R4(a, b, c, d, e, 60);

  R4(e, a, b, c, d, 61);

  R4(d, e, a, b, c, 62);

  R4(c, d, e, a, b, 63);

  R4(b, c, d, e, a, 64);

  R4(a, b, c, d, e, 65);

  R4(e, a, b, c, d, 66);

  R4(d, e, a, b, c, 67);

  R4(c, d, e, a, b, 68);

  R4(b, c, d, e, a, 69);

  R4(a, b, c, d, e, 70);

  R4(e, a, b, c, d, 71);

  R4(d, e, a, b, c, 72);

  R4(c, d, e, a, b, 73);

  R4(b, c, d, e, a, 74);

  R4(a, b, c, d, e, 75);

  R4(e, a, b, c, d, 76);

  R4(d, e, a, b, c, 77);

  R4(c, d, e, a, b, 78);

  R4(b, c, d, e, a, 79);

  /* Add the working vars back into context.state[] */

  state[0] += a;

  state[1] += b;

  state[2] += c;

  state[3] += d;

  state[4] += e;

  /* Wipe variables */

#ifdef HAVE_EXPLICIT_BZERO

  explicit_bzero(&a, sizeof(a));

  explicit_bzero(&b, sizeof(b));

  explicit_bzero(&c, sizeof(c));

  explicit_bzero(&d, sizeof(d));

  explicit_bzero(&e, sizeof(e));

#else

  a = b = c = d = e = 0;

#endif

#ifdef UL_SHA1HANDSOFF

  memset(block, '\0', sizeof(block));

#endif

}

/* SHA1Init - Initialize new context */

void ul_SHA1Init(UL_SHA1_CTX *context)

{

  /* SHA1 initialization constants */

  context->state[0] = 0x67452301;

  context->state[1] = 0xEFCDAB89;

  context->state[2] = 0x98BADCFE;

  context->state[3] = 0x10325476;

  context->state[4] = 0xC3D2E1F0;

  context->count[0] = context->count[1] = 0;

}

/* Run your data through this. */

void ul_SHA1Update(UL_SHA1_CTX *context, const unsigned char *data, uint32_t len)

{

  uint32_t i;

  uint32_t j;

  j = context->count[0];

  if ((context->count[0] += len << 3) < j)

    context->count[1]++;

  context->count[1] += (len >> 29);

  j = (j >> 3) & 63;

  if ((j + len) > 63) {

    memcpy(&context->buffer[j], data, (i = 64 - j));

    ul_SHA1Transform(context->state, context->buffer);

    for (; i + 63 < len; i += 64) {

      ul_SHA1Transform(context->state, &data[i]);

    }

    j = 0;

  } else

    i = 0;

  memcpy(&context->buffer[j], &data[i], len - i);

}

/* Add padding and return the message digest. */

void ul_SHA1Final(unsigned char digest[20], UL_SHA1_CTX *context)

{

  unsigned i;

  unsigned char finalcount[8];

  unsigned char c;

#if 0       /* untested "improvement" by DHR */

  /* Convert context->count to a sequence of bytes

   * in finalcount.  Second element first, but

   * big-endian order within element.

   * But we do it all backwards.

   */

  unsigned char *fcp = &finalcount[8];

  for (i = 0; i < 2; i++) {

    uint32_t t = context->count[i];

    int j;

    for (j = 0; j < 4; t >>= 8, j++)

      *--fcp = (unsigned char)t}

#else

  for (i = 0; i < 8; i++) {

    finalcount[i] = (unsigned char)((context->count[(i >= 4 ? 0 : 1)] >> ((3 - (i & 3)) * 8)) & 255);  /* Endian independent */

  }

#endif

  c = 0200;

  ul_SHA1Update(context, &c, 1);

  while ((context->count[0] & 504) != 448) {

    c = 0000;

    ul_SHA1Update(context, &c, 1);

  }

  ul_SHA1Update(context, finalcount, 8);  /* Should cause a SHA1Transform() */

  for (i = 0; i < 20; i++) {

    digest[i] = (unsigned char)

        ((context->state[i >> 2] >> ((3 - (i & 3)) * 8)) & 255);

  }

  /* Wipe variables */

  memset(context, '\0', sizeof(*context));

  memset(&finalcount, '\0', sizeof(finalcount));

}

void ul_SHA1(char *hash_out, const char *str, unsigned len)

{

  UL_SHA1_CTX ctx;

  unsigned int ii;

  ul_SHA1Init(&ctx);

  for (ii = 0; ii < len; ii += 1)

    ul_SHA1Update(&ctx, (const unsigned char *)str + ii, 1);

  ul_SHA1Final((unsigned char *)hash_out, &ctx);

  hash_out[20] = '\0';

}