NAME

       kcapi_cipher_dec_aes_ctr - Convenience function for AES CTR decryption

SYNOPSIS

       ssize_t kcapi_cipher_dec_aes_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 AES 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 AES type (AES-128, AES-192 or AES-256) is determined by the size of the given key. If
       the key is 16 bytes long, AES-128 is used. A 24 byte key implies AES-192 and a 32 byte key
       implies AES-256.

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

AUTHOR

       Stephan Mueller <smueller@chronox.de>
           Author.

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