NAME

       kcapi_cipher_dec_sm4_ctr - Convenience function for SM4 CTR decryption

SYNOPSIS

       ssize_t kcapi_cipher_dec_sm4_ctr(const uint8_t * key, uint32_t keylen, const uint8_t * in, size_t inlen,
                                        const uint8_t * ctr, 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

       ctr
           [in] start counter value to be used for cipher operation

       out
           [out] plaintext data buffer

       outlen
           [in] length of out buffer

DESCRIPTION

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

       The input buffer can be of arbitrary length.

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

       The start counter can contain all zeros (not a NULL buffer!) and 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.

COPYRIGHT

libkcapi Manual 1.5.0                              April 2024                            KCAPI_CIPHER_DEC_SM4(3)