FFmpeg: libavutil/aes_ctr.h Source File

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libavutil

aes_ctr.h

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1 /*

2 * AES-CTR cipher

4 *

5 * This file is part of FFmpeg.

6 *

7 * FFmpeg is free software; you can redistribute it and/or

8 * modify it under the terms of the GNU Lesser General Public

9 * License as published by the Free Software Foundation; either

10 * version 2.1 of the License, or (at your option) any later version.

11 *

12 * FFmpeg is distributed in the hope that it will be useful,

13 * but WITHOUT ANY WARRANTY; without even the implied warranty of

14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

15 * Lesser General Public License for more details.

16 *

17 * You should have received a copy of the GNU Lesser General Public

18 * License along with FFmpeg; if not, write to the Free Software

19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

20 */

22 #ifndef AVUTIL_AES_CTR_H

23 #define AVUTIL_AES_CTR_H

25 /**

26 * @defgroup lavu_aes_ctr AES-CTR

27 * @ingroup lavu_crypto

28 * @{

29 */

31 #include <stdint.h>

33 #include "attributes.h"

35 #define AES_CTR_KEY_SIZE (16)

36 #define AES_CTR_IV_SIZE (8)

38 struct AVAESCTR;

40 /**

41 * Allocate an AVAESCTR context.

42 */

43 struct AVAESCTR *av_aes_ctr_alloc(void);

45 /**

46 * Initialize an AVAESCTR context.

47 *

48 * @param a The AVAESCTR context to initialize

49 * @param key encryption key, must have a length of AES_CTR_KEY_SIZE

50 */

51 int av_aes_ctr_init(struct AVAESCTR *a, const uint8_t *key);

53 /**

54 * Release an AVAESCTR context.

55 *

56 * @param a The AVAESCTR context

57 */

58 void av_aes_ctr_free(struct AVAESCTR *a);

60 /**

61 * Process a buffer using a previously initialized context.

62 *

63 * @param a The AVAESCTR context

64 * @param dst destination array, can be equal to src

65 * @param src source array, can be equal to dst

66 * @param size the size of src and dst

67 */

68 void av_aes_ctr_crypt(struct AVAESCTR *a, uint8_t *dst, const uint8_t *src, int size);

70 /**

71 * Get the current iv

72 */

73 const uint8_t* av_aes_ctr_get_iv(struct AVAESCTR *a);

75 /**

76 * Generate a random iv

77 */

78 void av_aes_ctr_set_random_iv(struct AVAESCTR *a);

80 /**

81 * Forcefully change the 8-byte iv

82 */

83 void av_aes_ctr_set_iv(struct AVAESCTR *a, const uint8_t* iv);

85 /**

86 * Forcefully change the "full" 16-byte iv, including the counter

87 */

88 void av_aes_ctr_set_full_iv(struct AVAESCTR *a, const uint8_t* iv);

90 /**

91 * Increment the top 64 bit of the iv (performed after each frame)

92 */

93 void av_aes_ctr_increment_iv(struct AVAESCTR *a);

95 /**

96 * @}

97 */

99 #endif /* AVUTIL_AES_CTR_H */

av_aes_ctr_set_random_iv

void av_aes_ctr_set_random_iv(struct AVAESCTR *a)

Generate a random iv.

Definition: aes_ctr.c:64

av_aes_ctr_get_iv

const uint8_t * av_aes_ctr_get_iv(struct AVAESCTR *a)

Get the current iv.

Definition: aes_ctr.c:59

key

const char * key

Definition: hwcontext_opencl.c:189

av_aes_ctr_alloc

struct AVAESCTR * av_aes_ctr_alloc(void)

Allocate an AVAESCTR context.

Definition: aes_ctr.c:41

av_aes_ctr_init

int av_aes_ctr_init(struct AVAESCTR *a, const uint8_t *key)

Initialize an AVAESCTR context.

Definition: aes_ctr.c:74

dst

uint8_t ptrdiff_t const uint8_t ptrdiff_t int intptr_t intptr_t int int16_t * dst

Definition: dsp.h:87

size

int size

Definition: twinvq_data.h:10344

av_aes_ctr_set_iv

void av_aes_ctr_set_iv(struct AVAESCTR *a, const uint8_t *iv)

Forcefully change the 8-byte iv.

Definition: aes_ctr.c:46

av_aes_ctr_set_full_iv

void av_aes_ctr_set_full_iv(struct AVAESCTR *a, const uint8_t *iv)

Forcefully change the "full" 16-byte iv, including the counter.

Definition: aes_ctr.c:53

The reader does not expect b to be semantically here and if the code is changed by maybe adding a a division or other the signedness will almost certainly be mistaken To avoid this confusion a new type was SUINT is the C unsigned type but it holds a signed int to use the same example SUINT a

Definition: undefined.txt:41

attributes.h

av_aes_ctr_free

void av_aes_ctr_free(struct AVAESCTR *a)

Release an AVAESCTR context.

Definition: aes_ctr.c:84

av_aes_ctr_increment_iv

void av_aes_ctr_increment_iv(struct AVAESCTR *a)

Increment the top 64 bit of the iv (performed after each frame)

Definition: aes_ctr.c:95

av_aes_ctr_crypt

void av_aes_ctr_crypt(struct AVAESCTR *a, uint8_t *dst, const uint8_t *src, int size)