int norx_aead_decrypt(
unsigned char *p, size_t *plen,
const unsigned char *h, size_t hlen,
const unsigned char *c, size_t clen,
const unsigned char *t, size_t tlen,
const unsigned char *nonce,
const unsigned char *key
)
{
unsigned char tag[BYTES(NORX_A)];
norx_state_t state;
int result = -1;
if (clen < BYTES(NORX_A))
return -1;
#if defined(DEBUG)
printf("DECRYPTION\n");
#endif
norx_init(state, key, nonce);
norx_process_header(state, h, hlen);
norx_decrypt_msg(state, p, c, clen - BYTES(NORX_A));
norx_process_trailer(state, t, tlen);
norx_output_tag(state, tag);
*plen = clen - BYTES(NORX_A);
result = norx_verify_tag(c + clen - BYTES(NORX_A), tag);
if(result != 0) /* burn decrypted plaintext on auth failure */
burn(p, 0, clen - BYTES(NORX_A));
burn(state, 0, sizeof(norx_state_t));
return result;
}
int norx_aead_decrypt(
unsigned char *m, size_t *mlen,
const unsigned char *a, size_t alen,
const unsigned char *c, size_t clen,
const unsigned char *z, size_t zlen,
const unsigned char *nonce,
const unsigned char *key
)
{
int result = -1;
unsigned char tag[BYTES(NORX_T)];
norx_state_t state;
if (clen < BYTES(NORX_T)) {
return -1;
}
norx_init(state, key, nonce);
norx_absorb_data(state, a, alen, HEADER_TAG);
norx_decrypt_data(state, m, c, clen - BYTES(NORX_T));
norx_absorb_data(state, z, zlen, TRAILER_TAG);
norx_finalise(state, tag);
*mlen = clen - BYTES(NORX_T);
result = norx_verify_tag(c + clen - BYTES(NORX_T), tag);
if (result != 0) { /* burn decrypted plaintext on auth failure */
burn(m, 0, clen - BYTES(NORX_T));
}
burn(state, 0, sizeof(norx_state_t));
return result;
}
/* High-level operations */
void norx_aead_encrypt(
unsigned char *c, size_t *clen,
const unsigned char *a, size_t alen,
const unsigned char *m, size_t mlen,
const unsigned char *z, size_t zlen,
const unsigned char *nonce,
const unsigned char *key
)
{
norx_state_t state;
norx_init(state, key, nonce);
norx_absorb_data(state, a, alen, HEADER_TAG);
norx_encrypt_data(state, c, m, mlen);
norx_absorb_data(state, z, zlen, TRAILER_TAG);
norx_finalise(state, c + mlen);
*clen = mlen + BYTES(NORX_T);
burn(state, 0, sizeof(norx_state_t));
}
void norx_aead_encrypt(
unsigned char *c, size_t *clen,
const unsigned char *h, size_t hlen,
const unsigned char *p, size_t plen,
const unsigned char *t, size_t tlen,
const unsigned char *nonce,
const unsigned char *key
)
{
norx_state_t state;
#if defined(NORX_DEBUG)
printf("ENCRYPTION\n");
#endif
norx_init(state, key, nonce);
norx_process_header(state, h, hlen);
norx_encrypt_msg(state, c, p, plen);
norx_process_trailer(state, t, tlen);
norx_output_tag(state, c + plen); /* append tag to ciphertext */
*clen = plen + BYTES(NORX_A);
burn(state, 0, sizeof(norx_state_t));
}
