/* compute TLSv1 PRF (pseudo random function using HMAC) */
static void doPRF(byte* digest, word32 digLen, const byte* secret,word32 secLen,
const byte* label, word32 labLen, const byte* seed, word32 seedLen)
{
word32 half = (secLen + 1) / 2;
byte md5_half[MAX_PRF_HALF]; /* half is real size */
byte sha_half[MAX_PRF_HALF]; /* half is real size */
byte labelSeed[MAX_PRF_LABSEED]; /* labLen + seedLen is real size */
byte md5_result[MAX_PRF_DIG]; /* digLen is real size */
byte sha_result[MAX_PRF_DIG]; /* digLen is real size */
if (half > MAX_PRF_HALF)
return;
if (labLen + seedLen > MAX_PRF_LABSEED)
return;
if (digLen > MAX_PRF_DIG)
return;
XMEMSET(md5_result, 0, digLen);
XMEMSET(sha_result, 0, digLen);
XMEMCPY(md5_half, secret, half);
XMEMCPY(sha_half, secret + half - secLen % 2, half);
XMEMCPY(labelSeed, label, labLen);
XMEMCPY(labelSeed + labLen, seed, seedLen);
p_hash(md5_result, digLen, md5_half, half, labelSeed, labLen + seedLen,
md5_mac);
p_hash(sha_result, digLen, sha_half, half, labelSeed, labLen + seedLen,
sha_mac);
get_xor(digest, digLen, md5_result, sha_result);
}
/* Wrapper to call straight thru to p_hash in TSL 1.2 cases to remove stack
use */
static void PRF(byte* digest, word32 digLen, const byte* secret, word32 secLen,
const byte* label, word32 labLen, const byte* seed, word32 seedLen,
int useAtLeastSha256, int hash_type)
{
if (useAtLeastSha256) {
byte labelSeed[MAX_PRF_LABSEED]; /* labLen + seedLen is real size */
if (labLen + seedLen > MAX_PRF_LABSEED)
return;
XMEMCPY(labelSeed, label, labLen);
XMEMCPY(labelSeed + labLen, seed, seedLen);
/* If a cipher suite wants an algorithm better than sha256, it
* should use better. */
if (hash_type < sha256_mac)
hash_type = sha256_mac;
p_hash(digest, digLen, secret, secLen, labelSeed, labLen + seedLen,
hash_type);
}
#ifndef NO_OLD_TLS
else
doPRF(digest, digLen, secret, secLen, label, labLen, seed, seedLen);
#endif
}
static void
printrans(ACISM const*psp, STATE s, char const *charv,
FILE *out, MEMREF const *pattv)
{
(void)pattv;
TRAN x = psp->tranv[s];
if (!x) {
fprintf(out, "(empty)\n");
return;
}
SYMBOL sym = t_sym(psp,x);
char c = charv[sym];
if (sym)
fprintf(out, "--");
else
fprintf(out, "%02X ", c);
putc("M-"[!(x & IS_MATCH)], out);
putc("S-"[!(x & IS_SUFFIX)], out);
STATE next = t_next(psp, x);
if (t_isleaf(psp, x)) {
fprintf(out, " => %d\n", t_strno(psp, x));
} else {
fprintf(out, " %7"FX"d", next);
if (x & IS_MATCH) {
int i;
for (i = p_hash(psp, s); psp->hashv[i].state != s; ++i);
fprintf(out, " #> %"FX"d", psp->hashv[i].strno);
}
putc('\n', out);
}
}
//--------------|---------------------------------------------
void
acism_dump(ACISM const* psp, PS_DUMP_TYPE pdt, FILE *out, MEMREF const*pattv)
{
int i, empty;
char charv[256];
int symdist[257] = {};
for (i = 256; --i >=0;) charv[psp->symv[i]] = i;
if (pdt & PS_STATS) {
for (i = psp->tran_size, empty = 0; --i >= 0;) {
if (psp->tranv[i]) {
++symdist[t_sym(psp, psp->tranv[i])];
} else ++empty;
}
fprintf(out, "strs:%zu syms:%zu chars:%zu "
"trans:%d empty:%d mod:%d hash:%d size:%lu\n",
psp->nstrs, psp->nsyms, psp->nchars,
psp->tran_size, empty, psp->hash_mod, psp->hash_size,
(long)sizeof(ACISM) + p_size(psp));
}
if (pdt & PS_TRAN) {
fprintf(out, "==== TRAN:\n%8s %8s Ch MS %8s\n", "Cell", "State", "Next");
for (i = 1; i < (int)psp->tran_size; ++i) {
fprintf(out, "%8d %8d ", i, i - t_sym(psp, psp->tranv[i]));
printrans(psp, i, charv, out, pattv);
}
}
if (pdt & PS_HASH) {
fprintf(out, "==== HASH:\n.....: state strno\n");
for (i = 0; i < (int)psp->hash_size; ++i) {
STATE state = psp->hashv[i].state;
if (state)
fprintf(out, "%5d: %7"FX"u %3d %8"FX"u %.*s\n",
i, state, i - p_hash(psp, state),
PSTR(psp, psp->hashv[i].strno, pattv));
else
fprintf(out, "%5d: %7"FX"d --- %8"FX"d\n", i, state,
psp->hashv[i].strno);
}
}
if (pdt & PS_TREE) {
fprintf(out, "==== TREE:\n");
char str[psp->maxlen + 1];
printree(psp, 0, 0, str, charv, out, pattv);
}
//TODO: calculate stats: backref chain lengths ...
}
// compute TLSv1 PRF (pseudo random function using HMAC)
void PRF(byte* digest, uint digLen, const byte* secret, uint secLen,
const byte* label, uint labLen, const byte* seed, uint seedLen)
{
uint half = (secLen + 1) / 2;
output_buffer md5_half(half);
output_buffer sha_half(half);
output_buffer labelSeed(labLen + seedLen);
md5_half.write(secret, half);
sha_half.write(secret + half - secLen % 2, half);
labelSeed.write(label, labLen);
labelSeed.write(seed, seedLen);
output_buffer md5_result(digLen);
output_buffer sha_result(digLen);
p_hash(md5_result, md5_half, labelSeed, md5);
p_hash(sha_result, sha_half, labelSeed, sha);
md5_result.set_current(0);
sha_result.set_current(0);
get_xor(digest, digLen, md5_result, sha_result);
}
int
acism_lookup(ac_trie_t const *psp, const char *text, size_t len,
ACISM_ACTION *cb, void *context, int *statep, bool caseless)
{
ac_trie_t const ps = *psp;
char const *cp = text, *endp = cp + len;
uint8_t s;
STATE state = *statep;
int ret = 0;
while (cp < endp) {
s = caseless ? g_ascii_tolower (*cp++) : *cp++;
_SYMBOL sym = ps.symv[s];
if (!sym) {
// Input byte is not in any pattern string.
state = ROOT;
continue;
}
// Search for a valid transition from this (state, sym),
// following the backref chain.
TRAN next;
while (!t_valid(&ps, next = p_tran(&ps, state, sym)) && state != ROOT) {
TRAN back = p_tran(&ps, state, BACK);
state = t_valid(&ps, back) ? t_next(&ps, back) : ROOT;
}
if (!t_valid(&ps, next))
continue;
if (!(next & (IS_MATCH | IS_SUFFIX))) {
// No complete match yet; keep going.
state = t_next(&ps, next);
continue;
}
// At this point, one or more patterns have matched.
// Find all matches by following the backref chain.
// A valid node for (sym) with no SUFFIX flag marks the
// end of the suffix chain.
// In the same backref traversal, find a new (state),
// if the original transition is to a leaf.
STATE s = state;
// Initially state is ROOT. The chain search saves the
// first state from which the next char has a transition.
state = t_isleaf(&ps, next) ? 0 : t_next(&ps, next);
while (1) {
if (t_valid(&ps, next)) {
if (next & IS_MATCH) {
unsigned strno, ss = s + sym, i;
if (t_isleaf(&ps, ps.tranv[ss])) {
strno = t_strno(&ps, ps.tranv[ss]);
} else {
for (i = p_hash(&ps, ss); ps.hashv[i].state != ss; ++i);
strno = ps.hashv[i].strno;
}
if ((ret = cb(strno, cp - text, context)))
goto EXIT;
}
if (!state && !t_isleaf(&ps, next))
state = t_next(&ps, next);
if ( state && !(next & IS_SUFFIX))
break;
}
if (s == ROOT)
break;
TRAN b = p_tran(&ps, s, BACK);
s = t_valid(&ps, b) ? t_next(&ps, b) : ROOT;
next = p_tran(&ps, s, sym);
}
}
EXIT:
*statep = state;
return ret;
}
