/*
* rotn_encrypt --
* A simple encryption example that passes data through unchanged.
*/
static int
rotn_encrypt(WT_ENCRYPTOR *encryptor, WT_SESSION *session,
uint8_t *src, size_t src_len,
uint8_t *dst, size_t dst_len,
size_t *result_lenp)
{
ROTN_ENCRYPTOR *rotn_encryptor = (ROTN_ENCRYPTOR *)encryptor;
uint32_t i;
(void)session; /* Unused */
if (dst_len < src_len + CHKSUM_LEN + IV_LEN)
return (ENOMEM);
/*
* !!! Most implementations would verify any needed
* checksum and initialize the IV here.
*/
i = CHKSUM_LEN + IV_LEN;
memcpy(&dst[i], &src[0], src_len);
/*
* Depending on whether we have a secret key or not,
* call the common rotate or shift function on the text portion
* of the destination buffer. Send in src_len as the length of
* the text.
*/
if (rotn_encryptor->shift_len == 0)
do_rotate((char *)dst + i, src_len, rotn_encryptor->rot_N);
else
do_shift(&dst[i], src_len,
rotn_encryptor->shift_forw, rotn_encryptor->shift_len);
/*
* Checksum the encrypted buffer and add the IV.
*/
i = 0;
make_cksum(&dst[i]);
i += CHKSUM_LEN;
make_iv(&dst[i]);
*result_lenp = dst_len;
return (0);
}
/*
* rotate_encrypt --
* A simple rotate encryption.
*/
static int
rotate_encrypt(WT_ENCRYPTOR *encryptor, WT_SESSION *session,
uint8_t *src, size_t src_len,
uint8_t *dst, size_t dst_len,
size_t *result_lenp)
{
MY_CRYPTO *my_crypto = (MY_CRYPTO *)encryptor;
uint32_t i;
(void)session; /* Unused */
++my_crypto->num_calls;
if (src == NULL)
return (0);
if (dst_len < src_len + CHKSUM_LEN + IV_LEN)
return (ENOMEM);
i = CHKSUM_LEN + IV_LEN;
/*
* Skip over space reserved for checksum and initialization
* vector. Copy text into destination buffer then encrypt
* in place.
*/
memcpy(&dst[i], &src[0], src_len);
/*
* Call common rotate function on the text portion of the
* destination buffer. Send in src_len as the length of
* the text.
*/
do_rotate((char *)dst + i, src_len, my_crypto->rot_N);
/*
* Checksum the encrypted buffer and add the IV.
*/
i = 0;
make_cksum(&dst[i]);
i += CHKSUM_LEN;
make_iv(&dst[i]);
*result_lenp = dst_len;
return (0);
}
