random_bytes_libsodium.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. * If the libsodium PHP extension is loaded, we'll use it above any other
  31. * solution.
  32. *
  33. * libsodium-php project:
  34. * @ref https://github.com/jedisct1/libsodium-php
  35. *
  36. * @param int $bytes
  37. *
  38. * @throws Exception
  39. *
  40. * @return string
  41. */
  42. function random_bytes($bytes)
  43. {
  44. try {
  45. $bytes = RandomCompat_intval($bytes);
  46. } catch (TypeError $ex) {
  47. throw new TypeError(
  48. 'random_bytes(): $bytes must be an integer'
  49. );
  50. }
  51. if ($bytes < 1) {
  52. throw new Error(
  53. 'Length must be greater than 0'
  54. );
  55. }
  56. /**
  57. * \Sodium\randombytes_buf() doesn't allow more than 2147483647 bytes to be
  58. * generated in one invocation.
  59. */
  60. if ($bytes > 2147483647) {
  61. $buf = '';
  62. for ($i = 0; $i < $bytes; $i += 1073741824) {
  63. $n = ($bytes - $i) > 1073741824
  64. ? 1073741824
  65. : $bytes - $i;
  66. $buf .= \Sodium\randombytes_buf($n);
  67. }
  68. } else {
  69. $buf = \Sodium\randombytes_buf($bytes);
  70. }
  71. if ($buf !== false) {
  72. if (RandomCompat_strlen($buf) === $bytes) {
  73. return $buf;
  74. }
  75. }
  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. }