random_bytes_com_dotnet.php 2.8 KB

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  1. <?php
  2. /**
  3. * Random_* Compatibility Library
  4. * for using the new PHP 7 random_* API in PHP 5 projects
  5. *
  6. * The MIT License (MIT)
  7. *
  8. * Copyright (c) 2015 - 2017 Paragon Initiative Enterprises
  9. *
  10. * Permission is hereby granted, free of charge, to any person obtaining a copy
  11. * of this software and associated documentation files (the "Software"), to deal
  12. * in the Software without restriction, including without limitation the rights
  13. * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  14. * copies of the Software, and to permit persons to whom the Software is
  15. * furnished to do so, subject to the following conditions:
  16. *
  17. * The above copyright notice and this permission notice shall be included in
  18. * all copies or substantial portions of the Software.
  19. *
  20. * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  21. * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  22. * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  23. * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  24. * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  25. * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  26. * SOFTWARE.
  27. */
  28. if (!is_callable('random_bytes')) {
  29. /**
  30. * Windows with PHP < 5.3.0 will not have the function
  31. * openssl_random_pseudo_bytes() available, so let's use
  32. * CAPICOM to work around this deficiency.
  33. *
  34. * @param int $bytes
  35. *
  36. * @throws Exception
  37. *
  38. * @return string
  39. */
  40. function random_bytes($bytes)
  41. {
  42. try {
  43. $bytes = RandomCompat_intval($bytes);
  44. } catch (TypeError $ex) {
  45. throw new TypeError(
  46. 'random_bytes(): $bytes must be an integer'
  47. );
  48. }
  49. if ($bytes < 1) {
  50. throw new Error(
  51. 'Length must be greater than 0'
  52. );
  53. }
  54. $buf = '';
  55. if (!class_exists('COM')) {
  56. throw new Error(
  57. 'COM does not exist'
  58. );
  59. }
  60. $util = new COM('CAPICOM.Utilities.1');
  61. $execCount = 0;
  62. /**
  63. * Let's not let it loop forever. If we run N times and fail to
  64. * get N bytes of random data, then CAPICOM has failed us.
  65. */
  66. do {
  67. $buf .= base64_decode($util->GetRandom($bytes, 0));
  68. if (RandomCompat_strlen($buf) >= $bytes) {
  69. /**
  70. * Return our random entropy buffer here:
  71. */
  72. return RandomCompat_substr($buf, 0, $bytes);
  73. }
  74. ++$execCount;
  75. } while ($execCount < $bytes);
  76. /**
  77. * If we reach here, PHP has failed us.
  78. */
  79. throw new Exception(
  80. 'Could not gather sufficient random data'
  81. );
  82. }
  83. }