kcapi_cipher_dec_sm4_cbc - Man Page

Convenience function for SM4 CBC decryption

Synopsis

ssize_t kcapi_cipher_dec_sm4_cbc(const uint8_t * key, uint32_t keylen, const uint8_t * in, size_t inlen, const uint8_t * iv, uint8_t * out, size_t outlen);

Arguments

key

[in] key buffer

keylen

[in] length of key buffer

in

[in] ciphertext data buffer

inlen

[in] length of in buffer

iv

[in] IV to be used for cipher operation

out

[out] plaintext data buffer

outlen

[in] length of out buffer

Description

The convenience function performs an SM4 CBC decryption operation using the provided key, the given input buffer and the given IV. The output is stored in the out buffer.

Note, SM4 CBC requires an input data that is a multiple of 16 bytes. If you have data that is not guaranteed to be multiples of 16 bytes, either add zero bytes at the end of the buffer to pad it up to a multiple of 16 bytes. Otherwise, the CTR mode encryption operation may be usable.

The output buffer must be at least as large as the input buffer.

The IV must be exactly 16 bytes in size.

The SM4 key is fixed 16 bytes long.

return number of bytes generated upon success; a negative errno-style error code if an error occurred

Author

Stephan Mueller <smueller@chronox.de>

Author.

Info

August 2022 libkcapi Manual 1.4.0 Programming Interface