sha1.js 2.3 KB

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  1. function f(s, x, y, z) {
  2. switch (s) {
  3. case 0:
  4. return (x & y) ^ (~x & z);
  5. case 1:
  6. return x ^ y ^ z;
  7. case 2:
  8. return (x & y) ^ (x & z) ^ (y & z);
  9. case 3:
  10. return x ^ y ^ z;
  11. }
  12. }
  13. function ROTL(x, n) {
  14. return (x << n) | (x >>> (32 - n));
  15. }
  16. function sha1(bytes) {
  17. const K = [0x5a827999, 0x6ed9eba1, 0x8f1bbcdc, 0xca62c1d6];
  18. const H = [0x67452301, 0xefcdab89, 0x98badcfe, 0x10325476, 0xc3d2e1f0];
  19. const newBytes = new Uint8Array(bytes.length + 1);
  20. newBytes.set(bytes);
  21. newBytes[bytes.length] = 0x80;
  22. bytes = newBytes;
  23. const l = bytes.length / 4 + 2;
  24. const N = Math.ceil(l / 16);
  25. const M = new Array(N);
  26. for (let i = 0; i < N; ++i) {
  27. const arr = new Uint32Array(16);
  28. for (let j = 0; j < 16; ++j) {
  29. arr[j] =
  30. (bytes[i * 64 + j * 4] << 24) |
  31. (bytes[i * 64 + j * 4 + 1] << 16) |
  32. (bytes[i * 64 + j * 4 + 2] << 8) |
  33. bytes[i * 64 + j * 4 + 3];
  34. }
  35. M[i] = arr;
  36. }
  37. M[N - 1][14] = ((bytes.length - 1) * 8) / Math.pow(2, 32);
  38. M[N - 1][14] = Math.floor(M[N - 1][14]);
  39. M[N - 1][15] = ((bytes.length - 1) * 8) & 0xffffffff;
  40. for (let i = 0; i < N; ++i) {
  41. const W = new Uint32Array(80);
  42. for (let t = 0; t < 16; ++t) {
  43. W[t] = M[i][t];
  44. }
  45. for (let t = 16; t < 80; ++t) {
  46. W[t] = ROTL(W[t - 3] ^ W[t - 8] ^ W[t - 14] ^ W[t - 16], 1);
  47. }
  48. let a = H[0];
  49. let b = H[1];
  50. let c = H[2];
  51. let d = H[3];
  52. let e = H[4];
  53. for (let t = 0; t < 80; ++t) {
  54. const s = Math.floor(t / 20);
  55. const T = (ROTL(a, 5) + f(s, b, c, d) + e + K[s] + W[t]) >>> 0;
  56. e = d;
  57. d = c;
  58. c = ROTL(b, 30) >>> 0;
  59. b = a;
  60. a = T;
  61. }
  62. H[0] = (H[0] + a) >>> 0;
  63. H[1] = (H[1] + b) >>> 0;
  64. H[2] = (H[2] + c) >>> 0;
  65. H[3] = (H[3] + d) >>> 0;
  66. H[4] = (H[4] + e) >>> 0;
  67. }
  68. return Uint8Array.of(H[0] >> 24, H[0] >> 16, H[0] >> 8, H[0], H[1] >> 24, H[1] >> 16, H[1] >> 8, H[1], H[2] >> 24, H[2] >> 16, H[2] >> 8, H[2], H[3] >> 24, H[3] >> 16, H[3] >> 8, H[3], H[4] >> 24, H[4] >> 16, H[4] >> 8, H[4]);
  69. }
  70. export default sha1;