rc4.h 1.6 KB

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  1. /*
  2. * RC4 encryption/decryption/pseudo-random number generator
  3. *
  4. * This file is part of FFmpeg.
  5. *
  6. * FFmpeg is free software; you can redistribute it and/or
  7. * modify it under the terms of the GNU Lesser General Public
  8. * License as published by the Free Software Foundation; either
  9. * version 2.1 of the License, or (at your option) any later version.
  10. *
  11. * FFmpeg is distributed in the hope that it will be useful,
  12. * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13. * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14. * Lesser General Public License for more details.
  15. *
  16. * You should have received a copy of the GNU Lesser General Public
  17. * License along with FFmpeg; if not, write to the Free Software
  18. * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  19. */
  20. #ifndef AVUTIL_RC4_H
  21. #define AVUTIL_RC4_H
  22. #include <stdint.h>
  23. struct AVRC4 {
  24. uint8_t state[256];
  25. int x, y;
  26. };
  27. /**
  28. * @brief Initializes an AVRC4 context.
  29. *
  30. * @param key_bits must be a multiple of 8
  31. * @param decrypt 0 for encryption, 1 for decryption, currently has no effect
  32. */
  33. int av_rc4_init(struct AVRC4 *d, const uint8_t *key, int key_bits, int decrypt);
  34. /**
  35. * @brief Encrypts / decrypts using the RC4 algorithm.
  36. *
  37. * @param count number of bytes
  38. * @param dst destination array, can be equal to src
  39. * @param src source array, can be equal to dst, may be NULL
  40. * @param iv not (yet) used for RC4, should be NULL
  41. * @param decrypt 0 for encryption, 1 for decryption, not (yet) used
  42. */
  43. void av_rc4_crypt(struct AVRC4 *d, uint8_t *dst, const uint8_t *src, int count, uint8_t *iv, int decrypt);
  44. #endif /* AVUTIL_RC4_H */