/** Verifies and decrypts a packet */
static bool method_decrypt(fastd_peer_t *peer, fastd_method_session_state_t *session, fastd_buffer_t *out, fastd_buffer_t in, bool *reordered) {
if (in.len < COMMON_HEADBYTES+sizeof(fastd_block128_t))
return false;
if (!method_session_is_valid(session))
return false;
uint8_t in_nonce[COMMON_NONCEBYTES];
uint8_t flags;
int64_t age;
if (!fastd_method_handle_common_header(&session->common, &in, in_nonce, &flags, &age))
return false;
if (flags)
return false;
uint8_t nonce[session->method->cipher_info->iv_length] __attribute__((aligned(8)));
fastd_method_expand_nonce(nonce, in_nonce, sizeof(nonce));
size_t tail_len = alignto(in.len, sizeof(fastd_block128_t))-in.len;
*out = fastd_buffer_alloc(in.len, 0, tail_len);
int n_blocks = block_count(in.len, sizeof(fastd_block128_t));
fastd_block128_t *inblocks = in.data;
fastd_block128_t *outblocks = out->data;
fastd_block128_t tag;
bool ok = session->cipher->crypt(session->cipher_state, outblocks, inblocks, n_blocks*sizeof(fastd_block128_t), nonce);
if (ok) {
if (tail_len)
memset(in.data+in.len, 0, tail_len);
put_size(&inblocks[n_blocks], in.len-sizeof(fastd_block128_t));
ok = session->ghash->digest(session->ghash_state, &tag, inblocks+1, n_blocks*sizeof(fastd_block128_t));
}
if (!ok || !block_equal(&tag, &outblocks[0])) {
fastd_buffer_free(*out);
return false;
}
fastd_buffer_free(in);
fastd_buffer_push_head(out, sizeof(fastd_block128_t));
fastd_tristate_t reorder_check = fastd_method_reorder_check(peer, &session->common, in_nonce, age);
if (reorder_check.set) {
*reordered = reorder_check.state;
}
else {
fastd_buffer_free(*out);
*out = fastd_buffer_alloc(0, 0, 0);
}
return true;
}
/** Encrypts and authenticates a packet */
static bool method_encrypt(UNUSED fastd_peer_t *peer, fastd_method_session_state_t *session, fastd_buffer_t *out, fastd_buffer_t in) {
fastd_buffer_pull_head_zero(&in, sizeof(fastd_block128_t));
size_t tail_len = alignto(in.len, sizeof(fastd_block128_t))-in.len;
*out = fastd_buffer_alloc(in.len, alignto(COMMON_HEADBYTES, 16), sizeof(fastd_block128_t)+tail_len);
if (tail_len)
memset(in.data+in.len, 0, tail_len);
uint8_t nonce[session->method->cipher_info->iv_length] __attribute__((aligned(8)));
fastd_method_expand_nonce(nonce, session->common.send_nonce, sizeof(nonce));
int n_blocks = block_count(in.len, sizeof(fastd_block128_t));
fastd_block128_t *inblocks = in.data;
fastd_block128_t *outblocks = out->data;
fastd_block128_t tag;
bool ok = session->cipher->crypt(session->cipher_state, outblocks, inblocks, n_blocks*sizeof(fastd_block128_t), nonce);
if (ok) {
if (tail_len)
memset(out->data+out->len, 0, tail_len);
put_size(&outblocks[n_blocks], in.len-sizeof(fastd_block128_t));
ok = session->ghash->digest(session->ghash_state, &tag, outblocks+1, n_blocks*sizeof(fastd_block128_t));
}
if (!ok) {
fastd_buffer_free(*out);
return false;
}
xor_a(&outblocks[0], &tag);
fastd_buffer_free(in);
fastd_method_put_common_header(out, session->common.send_nonce, 0);
fastd_method_increment_nonce(&session->common);
return true;
}
void read_in_sizes(const char *from_file) {
FILE *f = fopen(from_file, "rt");
if (f==NULL) {
return;
}
char *line = (char *) mc_malloc(10240*sizeof(char));
if (fgets(line, 10240, f) != NULL) {
char *ln = trim(line);
if (strcmp(ln, VFILESIZE_FILE_TYPE) == 0) {
if (fgets(line, 10240, f) != NULL) {
char *ln1 = trim(line);
if (strcmp(ln1, VFILESIZE_FILE_VERSION) == 0) {
while (fgets(line, 10240, f) != NULL) {
char *ln2 = trim(line);
char *vfile = mc_strdup( ln2 );
fgets(line, 10240, f);
char *ln3 = trim( line );
size_t size = (size_t) strtoul(ln3, NULL, 10);
fgets(line, 10240, f);
char *ln4 = trim (line);
time_t mtime = (time_t) strtoul(ln4, NULL, 10);
put_size( vfile, size, mtime );
mc_free( vfile);
mc_free( ln4 );
mc_free( ln3 );
mc_free( ln2 );
}
}
mc_free( ln1 );
}
}
mc_free( ln );
}
mc_free(line);
fclose(f);
}
