content: package im.actor.runtime.crypto.primitives.digest;
  
  import im.actor.runtime.crypto.primitives.util.Pack;
  
  import static im.actor.runtime.crypto.primitives.util.Pack.jsWrap;
  
  // Disabling Bounds checks for speeding up calculations
  
  /*-[
  #define J2OBJC_DISABLE_ARRAY_BOUND_CHECKS 1
  ]-*/
  
  /**
   * FIPS 180-2 implementation of SHA-256.
   * <p>
   * <pre>
   *         block  word  digest
   * SHA-1   512    32    160
   * SHA-256 512    32    256
   * SHA-384 1024   64    384
   * SHA-512 1024   64    512
   * </pre>
   */
  public class SHA256Digest extends GeneralDigest {
      private static final int DIGEST_LENGTH = 32;
  
      private int H1, H2, H3, H4, H5, H6, H7, H8;
  
      private int[] X = new int[64];
      private int xOff;
  
      /**
       * Standard constructor
       */
      public SHA256Digest() {
          reset();
      }
  
      public String getAlgorithmName() {
          return "SHA-256";
      }
  
      public int getDigestSize() {
          return DIGEST_LENGTH;
      }
  
      protected void processWord(byte[] in, int inOff) {
  
          // Note: Inlined for performance
          // X[xOff] = Pack.bigEndianToInt(in, inOff);
          int n = jsWrap(in[inOff] << 24);
          n |= jsWrap((in[++inOff] & 0xff) << 16);
          n |= jsWrap((in[++inOff] & 0xff) << 8);
          n |= jsWrap((in[++inOff] & 0xff));
          X[xOff] = n;
  
          if (++xOff == 16) {
              processBlock();
          }
      }
  
      protected void processLength(long bitLength) {
  
          if (xOff > 14) {
              processBlock();
          }
  
          X[14] = (int) ((bitLength >>> 32) & 0xFFFFFFFF);
          X[15] = (int) (bitLength & 0xffffffff);
      }
  
      public int doFinal(byte[] out, int outOff) {
  
          finish();
  
          Pack.intToBigEndian(H1, out, outOff);
          Pack.intToBigEndian(H2, out, outOff + 4);
          Pack.intToBigEndian(H3, out, outOff + 8);
          Pack.intToBigEndian(H4, out, outOff + 12);
          Pack.intToBigEndian(H5, out, outOff + 16);
          Pack.intToBigEndian(H6, out, outOff + 20);
          Pack.intToBigEndian(H7, out, outOff + 24);
          Pack.intToBigEndian(H8, out, outOff + 28);
  
          reset();
  
          return DIGEST_LENGTH;
      }
  
      /**
       * reset the chaining variables
       */
      public void reset() {
          super.reset();
  
          /* SHA-256 initial hash value
           * The first 32 bits of the fractional parts of the square roots
           * of the first eight prime numbers
           */
  
          H1 = 0x6a09e667;
          H2 = 0xbb67ae85;
          H3 = 0x3c6ef372;
          H4 = 0xa54ff53a;
          H5 = 0x510e527f;
          H6 = 0x9b05688c;
          H7 = 0x1f83d9ab;
          H8 = 0x5be0cd19;
  
          xOff = 0;
          for (int i = 0; i != X.length; i++) {
              X[i] = 0;
          }
      }
  
      protected void processBlock() {
          //
          // expand 16 word block into 64 word blocks.
          //
          for (int t = 16; t <= 63; t++) {
              X[t] = jsWrap(Theta1(X[t - 2]) + X[t - 7]);
              X[t] = jsWrap(X[t] + Theta0(X[t - 15]));
              X[t] = jsWrap(X[t] + X[t - 16]);
          }
  
          //
          // set up working variables.
          //
          int a = H1;
          int b = H2;
          int c = H3;
          int d = H4;
          int e = H5;
          int f = H6;
          int g = H7;
          int h = H8;
  
          int t = 0;
          for (int i = 0; i < 8; i++) {
  
              //// t = 8 * i
              // h += Sum1(e) + Ch(e, f, g) + K[t] + X[t];
              h = jsWrap(h + Sum1(e));
              h = jsWrap(h + Ch(e, f, g));
              h = jsWrap(h + K[t]);
              h = jsWrap(h + X[t]);
              // d += h
              d = jsWrap(d + h);
              // h += Sum0(a) + Maj(a, b, c)
              h = jsWrap(h + Sum0(a));
              h = jsWrap(h + Maj(a, b, c));
              ++t;
  
              //// t = 8 * i + 1
              // g += Sum1(d) + Ch(d, e, f) + K[t] + X[t];
              g = jsWrap(g + Sum1(d));
              g = jsWrap(g + Ch(d, e, f));
              g = jsWrap(g + K[t]);
              g = jsWrap(g + X[t]);
              // c += g;
              c = jsWrap(c + g);
              // g += Sum0(h) + Maj(h, a, b);
              g = jsWrap(g + Sum0(h));
              g = jsWrap(g + Maj(h, a, b));
              ++t;
  
              //// t = 8 * i + 2
              // f += Sum1(c) + Ch(c, d, e) + K[t] + X[t];
              f = jsWrap(f + Sum1(c));
              f = jsWrap(f + Ch(c, d, e));
              f = jsWrap(f + K[t]);
              f = jsWrap(f + X[t]);
              // b += f;
              b = jsWrap(b + f);
              // f += Sum0(g) + Maj(g, h, a);
              f = jsWrap(f + Sum0(g));
              f = jsWrap(f + Maj(g, h, a));
              ++t;
  
              // t = 8 * i + 3
              // e += Sum1(b) + Ch(b, c, d) + K[t] + X[t];
              e = jsWrap(e + Sum1(b));
              e = jsWrap(e + Ch(b, c, d));
              e = jsWrap(e + K[t]);
              e = jsWrap(e + X[t]);
              // a += e;
              a = jsWrap(a + e);
              // e += Sum0(f) + Maj(f, g, h);
              e = jsWrap(e + Sum0(f) + Maj(f, g, h));
              ++t;
  
              //// t = 8 * i + 4
              // d += Sum1(a) + Ch(a, b, c) + K[t] + X[t];
              d = jsWrap(d + Sum1(a));
              d = jsWrap(d + Ch(a, b, c));
              d = jsWrap(d + K[t]);
              d = jsWrap(d + X[t]);
              // h += d;
              h = jsWrap(h + d);
              // d += Sum0(e) + Maj(e, f, g);
              d = jsWrap(d + Sum0(e));
              d = jsWrap(d + Maj(e, f, g));
              ++t;
  
              //// t = 8 * i + 5
              // c += Sum1(h) + Ch(h, a, b) + K[t] + X[t];
              c = jsWrap(c + Sum1(h));
              c = jsWrap(c + Ch(h, a, b));
              c = jsWrap(c + K[t]);
              c = jsWrap(c + X[t]);
              // g += c;
              g = jsWrap(g + c);
              // c += Sum0(d) + Maj(d, e, f);
              c = jsWrap(c + Sum0(d));
              c = jsWrap(c + Maj(d, e, f));
              ++t;
  
              //// t = 8 * i + 6
              // b += Sum1(g) + Ch(g, h, a) + K[t] + X[t];
              b = jsWrap(b + Sum1(g));
              b = jsWrap(b + Ch(g, h, a));
              b = jsWrap(b + K[t]);
              b = jsWrap(b + X[t]);
              // f += b;
              f = jsWrap(f + b);
              // b += Sum0(c) + Maj(c, d, e);
              b = jsWrap(b + Sum0(c));
              b = jsWrap(b + Maj(c, d, e));
              ++t;
  
              //// t = 8 * i + 7
              // a += Sum1(f) + Ch(f, g, h) + K[t] + X[t];
              a = jsWrap(a + Sum1(f));
              a = jsWrap(a + Ch(f, g, h));
              a = jsWrap(a + K[t]);
              a = jsWrap(a + X[t]);
              // e += a;
              e = jsWrap(e + a);
              // a += Sum0(b) + Maj(b, c, d);
              a = jsWrap(a + Sum0(b));
              a = jsWrap(a + Maj(b, c, d));
              ++t;
          }
  
          H1 = jsWrap(H1 + a);
          H2 = jsWrap(H2 + b);
          H3 = jsWrap(H3 + c);
          H4 = jsWrap(H4 + d);
          H5 = jsWrap(H5 + e);
          H6 = jsWrap(H6 + f);
          H7 = jsWrap(H7 + g);
          H8 = jsWrap(H8 + h);
  
          //
          // reset the offset and clean out the word buffer.
          //
          xOff = 0;
          for (int i = 0; i < 16; i++) {
              X[i] = 0;
          }
      }
  
      /* SHA-256 functions */
      private int Ch(int x, int y, int z) {
          return jsWrap((x & y) ^ ((~x) & z));
      }
  
      private int Maj(int x, int y, int z) {
          return jsWrap((x & y) ^ (x & z) ^ (y & z));
      }
  
      private int Sum0(int x) {
          return jsWrap((jsWrap(x >>> 2) | jsWrap(x << 30)) ^ (jsWrap(x >>> 13) | jsWrap(x << 19)) ^ (jsWrap(x >>> 22) | jsWrap(x << 10)));
      }
  
      private int Sum1(int x) {
          return jsWrap((jsWrap(x >>> 6) | jsWrap(x << 26)) ^ (jsWrap(x >>> 11) | jsWrap(x << 21)) ^ (jsWrap(x >>> 25) | jsWrap(x << 7)));
      }
  
      private int Theta0(int x) {
          return jsWrap((jsWrap(x >>> 7) | jsWrap(x << 25)) ^ (jsWrap(x >>> 18) | jsWrap(x << 14)) ^ jsWrap(x >>> 3));
      }
  
      private int Theta1(int x) {
          return jsWrap((jsWrap(x >>> 17) | jsWrap(x << 15)) ^ (jsWrap(x >>> 19) | jsWrap(x << 13)) ^ jsWrap(x >>> 10));
      }
  
      /* SHA-256 Constants
       * (represent the first 32 bits of the fractional parts of the
       * cube roots of the first sixty-four prime numbers)
       */
      static final int K[] = {
              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
      };
  }
  
  