1KCAPI_CIPHER_DEC_SM4(3)      Programming Interface     KCAPI_CIPHER_DEC_SM4(3)
2
3
4

NAME

6       kcapi_cipher_dec_sm4_cbc - Convenience function for SM4 CBC decryption
7

SYNOPSIS

9       ssize_t kcapi_cipher_dec_sm4_cbc(const uint8_t * key, uint32_t keylen,
10                                        const uint8_t * in, size_t inlen,
11                                        const uint8_t * iv, uint8_t * out,
12                                        size_t outlen);
13

ARGUMENTS

15       key
16           [in] key buffer
17
18       keylen
19           [in] length of key buffer
20
21       in
22           [in] ciphertext data buffer
23
24       inlen
25           [in] length of in buffer
26
27       iv
28           [in] IV to be used for cipher operation
29
30       out
31           [out] plaintext data buffer
32
33       outlen
34           [in] length of out buffer
35

DESCRIPTION

37       The convenience function performs an SM4 CBC decryption operation using
38       the provided key, the given input buffer and the given IV. The output
39       is stored in the out buffer.
40
41       Note, SM4 CBC requires an input data that is a multiple of 16 bytes. If
42       you have data that is not guaranteed to be multiples of 16 bytes,
43       either add zero bytes at the end of the buffer to pad it up to a
44       multiple of 16 bytes. Otherwise, the CTR mode encryption operation may
45       be usable.
46
47       The output buffer must be at least as large as the input buffer.
48
49       The IV must be exactly 16 bytes in size.
50
51       The SM4 key is fixed 16 bytes long.
52
53       return number of bytes generated upon success; a negative errno-style
54       error code if an error occurred
55

AUTHOR

57       Stephan Mueller <smueller@chronox.de>
58           Author.
59

61libkcapi Manual 1.4.0            January 2023          KCAPI_CIPHER_DEC_SM4(3)
Impressum