* Switch received. Committed; send data; move to @KXS_SWITCH@.
*/
-/*----- Tunable parameters ------------------------------------------------*/
-
-#define T_VALID MIN(2) /* Challenge validity period */
-#define T_RETRY SEC(10) /* Challenge retransmit interval */
-
-#define VALIDP(kx, now) ((now) < (kx)->t_valid)
-
/*----- Static tables -----------------------------------------------------*/
static const char *const pkname[] = {
/*----- Various utilities -------------------------------------------------*/
+/* --- @VALIDP@ --- *
+ *
+ * Arguments: @const keyexch *kx@ = key exchange state
+ * @time_t now@ = current time in seconds
+ *
+ * Returns: Whether the challenge in the key-exchange state is still
+ * valid or should be regenerated.
+ */
+
+#define VALIDP(kx, now) ((now) < (kx)->t_valid)
+
/* --- @hashge@ --- *
*
* Arguments: @ghash *h@ = pointer to hash context
+ * @group *g@ = pointer to group
* @ge *x@ = pointer to group element
*
* Returns: ---
* @buf_t@.
*/
-static void hashge(ghash *h, ge *x)
+static void hashge(ghash *h, group *g, ge *x)
{
buf b;
+
buf_init(&b, buf_t, sizeof(buf_t));
- G_TOBUF(gg, &b, x);
+ G_TOBUF(g, &b, x);
assert(BOK(&b));
GH_HASH(h, BBASE(&b), BLEN(&b));
}
* Arguments: @buf *b@ = output buffer
* @mp *x@ = the plaintext integer
* @size_t n@ = the expected size of the plaintext
+ * @gcipher *mgfc@ = mask-generating function to use
* @const octet *k@ = pointer to key material
* @size_t ksz@ = size of the key
*
* it's a random oracle thing rather than an encryption thing.
*/
-static octet *mpmask(buf *b, mp *x, size_t n, const octet *k, size_t ksz)
+static octet *mpmask(buf *b, mp *x, size_t n,
+ const gccipher *mgfc, const octet *k, size_t ksz)
{
gcipher *mgf;
octet *p;
if ((p = buf_get(b, n)) == 0)
return (0);
- mgf = GC_INIT(algs.mgf, k, ksz);
+ mgf = GC_INIT(mgfc, k, ksz);
IF_TRACING(T_KEYEXCH, IF_TRACING(T_CRYPTO, {
- trace(T_CRYPTO, "masking index = %s", mpstr(x));
- trace_block(T_CRYPTO, "masking key", k, ksz);
+ trace(T_CRYPTO, "crypto: masking index = %s", mpstr(x));
+ trace_block(T_CRYPTO, "crypto: masking key", k, ksz);
}))
mp_storeb(x, buf_t, n);
GC_ENCRYPT(mgf, buf_t, p, n);
IF_TRACING(T_KEYEXCH, IF_TRACING(T_CRYPTO, {
- trace_block(T_CRYPTO, "index plaintext", buf_t, n);
- trace_block(T_CRYPTO, "masked ciphertext", p, n);
+ trace_block(T_CRYPTO, "crypto: index plaintext", buf_t, n);
+ trace_block(T_CRYPTO, "crypto: masked ciphertext", p, n);
}))
GC_DESTROY(mgf);
return (p);
* Arguments: @mp *d@ = the output integer
* @const octet *p@ = pointer to the ciphertext
* @size_t n@ = the size of the ciphertext
+ * @gcipher *mgfc@ = mask-generating function to use
* @const octet *k@ = pointer to key material
* @size_t ksz@ = size of the key
*
*/
static mp *mpunmask(mp *d, const octet *p, size_t n,
- const octet *k, size_t ksz)
+ const gccipher *mgfc, const octet *k, size_t ksz)
{
gcipher *mgf;
- mgf = GC_INIT(algs.mgf, k, ksz);
+ mgf = GC_INIT(mgfc, k, ksz);
IF_TRACING(T_KEYEXCH, IF_TRACING(T_CRYPTO, {
- trace_block(T_CRYPTO, "unmasking key", k, ksz);
- trace_block(T_CRYPTO, "masked ciphertext", p, n);
+ trace_block(T_CRYPTO, "crypto: unmasking key", k, ksz);
+ trace_block(T_CRYPTO, "crypto: masked ciphertext", p, n);
}))
GC_DECRYPT(mgf, p, buf_t, n);
d = mp_loadb(d, buf_t, n);
IF_TRACING(T_KEYEXCH, IF_TRACING(T_CRYPTO, {
- trace_block(T_CRYPTO, "index plaintext", buf_t, n);
- trace(T_CRYPTO, "unmasked index = %s", mpstr(d));
+ trace_block(T_CRYPTO, "crypto: index plaintext", buf_t, n);
+ trace(T_CRYPTO, "crypto: unmasked index = %s", mpstr(d));
}))
GC_DESTROY(mgf);
return (d);
/* --- @hashcheck@ --- *
*
- * Arguments: @ge *kpub@ = sender's public key
+ * Arguments: @keyexch *kx@ = pointer to key-exchange block
+ * @ge *kpub@ = sender's public key
* @ge *cc@ = receiver's challenge
* @ge *c@ = sender's challenge
* @ge *y@ = reply to sender's challenge
* key-exchange is deniable.
*/
-static const octet *hashcheck(ge *kpub, ge *cc, ge *c, ge *y)
+static const octet *hashcheck(keyexch *kx, ge *kpub, ge *cc, ge *c, ge *y)
{
- ghash *h = GH_INIT(algs.h);
+ ghash *h = GH_INIT(kx->kpriv->algs.h);
+ group *g = kx->kpriv->g;
HASH_STRING(h, "tripe-expected-reply");
- hashge(h, kpub);
- hashge(h, cc);
- hashge(h, c);
- hashge(h, y);
+ hashge(h, g, kpub);
+ hashge(h, g, cc);
+ hashge(h, g, c);
+ hashge(h, g, y);
GH_DONE(h, buf_t);
IF_TRACING(T_KEYEXCH, IF_TRACING(T_CRYPTO, {
- trace(T_CRYPTO, "computing challenge check hash");
- trace(T_CRYPTO, "public key = %s", gestr(gg, kpub));
- trace(T_CRYPTO, "receiver challenge = %s", gestr(gg, cc));
- trace(T_CRYPTO, "sender challenge = %s", gestr(gg, c));
- trace(T_CRYPTO, "sender reply = %s", gestr(gg, y));
- trace_block(T_CRYPTO, "hash output", buf_t, algs.hashsz);
+ trace(T_CRYPTO, "crypto: computing challenge check hash");
+ trace(T_CRYPTO, "crypto: public key = %s", gestr(g, kpub));
+ trace(T_CRYPTO, "crypto: receiver challenge = %s", gestr(g, cc));
+ trace(T_CRYPTO, "crypto: sender challenge = %s", gestr(g, c));
+ trace(T_CRYPTO, "crypto: sender reply = %s", gestr(g, y));
+ trace_block(T_CRYPTO, "crypto: hash output", buf_t, kx->kpriv->algs.hashsz);
}))
GH_DESTROY(h);
return (buf_t);
static void sendchallenge(keyexch *kx, buf *b, ge *c, const octet *hc)
{
- G_TOBUF(gg, b, kx->c);
- buf_put(b, hc, algs.hashsz);
- mpmask(b, kx->alpha, indexsz,
- hashcheck(kpub, c, kx->c, kx->rx), algs.hashsz);
+ G_TOBUF(kx->kpriv->g, b, kx->c);
+ buf_put(b, hc, kx->kpriv->algs.hashsz);
+ mpmask(b, kx->alpha, kx->kpriv->indexsz, kx->kpriv->algs.mgf,
+ hashcheck(kx, kx->kpriv->kpub, c, kx->c, kx->rx),
+ kx->kpriv->algs.hashsz);
}
/* --- @timer@ --- *
/* --- @settimer@ --- *
*
* Arguments: @keyexch *kx@ = pointer to key exchange context
- * @time_t t@ = when to set the timer for
+ * @struct timeval *tv@ = when to set the timer for
*
* Returns: ---
*
* Use: Sets the timer for the next key exchange attempt.
*/
-static void settimer(keyexch *kx, time_t t)
+static void settimer(keyexch *kx, struct timeval *tv)
{
- struct timeval tv;
- if (kx->f & KXF_TIMER)
- sel_rmtimer(&kx->t);
- tv.tv_sec = t;
- tv.tv_usec = 0;
- sel_addtimer(&sel, &kx->t, &tv, timer, kx);
+ if (kx->f & KXF_TIMER) sel_rmtimer(&kx->t);
+ sel_addtimer(&sel, &kx->t, tv, timer, kx);
kx->f |= KXF_TIMER;
}
+/* --- @f2tv@ --- *
+ *
+ * Arguments: @struct timeval *tv@ = where to write the timeval
+ * @double t@ = a time as a floating point number
+ *
+ * Returns: ---
+ *
+ * Use: Converts a floating-point time into a timeval.
+ */
+
+static void f2tv(struct timeval *tv, double t)
+{
+ tv->tv_sec = t;
+ tv->tv_usec = (t - tv->tv_sec)*MILLION;
+}
+
+/* --- @wobble@ --- *
+ *
+ * Arguments: @double t@ = a time interval
+ *
+ * Returns: The same time interval, with a random error applied.
+ */
+
+static double wobble(double t)
+{
+ uint32 r = rand_global.ops->word(&rand_global);
+ double w = (r/F_2P32) - 0.5;
+ return (t + t*w*T_WOBBLE);
+}
+
+/* --- @rs_time@ --- *
+ *
+ * Arguments: @retry *rs@ = current retry state
+ * @struct timeval *tv@ = where to write the result
+ * @const struct timeval *now@ = current time, or null
+ *
+ * Returns: ---
+ *
+ * Use: Computes a time at which to retry sending a key-exchange
+ * packet. This algorithm is subject to change, but it's
+ * currently a capped exponential backoff, slightly randomized
+ * to try to keep clients from hammering a server that's only
+ * just woken up.
+ *
+ * If @now@ is null then the function works out the time for
+ * itself.
+ */
+
+static void rs_time(retry *rs, struct timeval *tv, const struct timeval *now)
+{
+ double t;
+ struct timeval rtv;
+
+ if (!rs->t)
+ t = SEC(2);
+ else {
+ t = (rs->t * 5)/4;
+ if (t > MIN(5)) t = MIN(5);
+ }
+ rs->t = t;
+
+ if (!now) {
+ now = tv;
+ gettimeofday(tv, 0);
+ }
+ f2tv(&rtv, wobble(t));
+ TV_ADD(tv, now, &rtv);
+}
+
+/* --- @retry_reset@ --- *
+ *
+ * Arguments: @retry *rs@ = retry state
+ *
+ * Returns: --
+ *
+ * Use: Resets a retry state to indicate that progress has been
+ * made. Also useful for initializing the state in the first
+ * place.
+ */
+
+static void rs_reset(retry *rs) { rs->t = 0; }
+
/*----- Challenge management ----------------------------------------------*/
/* --- Notes on challenge management --- *
{
if (kxc->f & KXF_TIMER)
sel_rmtimer(&kxc->t);
- G_DESTROY(gg, kxc->c);
- G_DESTROY(gg, kxc->r);
+ G_DESTROY(kxc->kx->kpriv->g, kxc->c);
+ G_DESTROY(kxc->kx->kpriv->g, kxc->r);
ks_drop(kxc->ks);
DESTROY(kxc);
}
/* --- Fill in the new structure --- */
kxc = CREATE(kxchal);
- kxc->c = G_CREATE(gg);
- kxc->r = G_CREATE(gg);
+ kxc->c = G_CREATE(kx->kpriv->g);
+ kxc->r = G_CREATE(kx->kpriv->g);
kxc->ks = 0;
kxc->kx = kx;
kxc->f = 0;
kx->r[i] = kxc;
+ rs_reset(&kxc->rs);
return (kxc);
}
unsigned i;
for (i = 0; i < kx->nr; i++) {
- if (G_EQ(gg, c, kx->r[i]->c))
+ if (G_EQ(kx->kpriv->g, c, kx->r[i]->c))
return (kx->r[i]);
}
return (0);
unsigned i;
for (i = 0; i < kx->nr; i++) {
- if (memcmp(hc, kx->r[i]->hc, algs.hashsz) == 0)
+ if (memcmp(hc, kx->r[i]->hc, kx->kpriv->algs.hashsz) == 0)
return (kx->r[i]);
}
return (0);
T( trace(T_KEYEXCH, "keyexch: sending reply to `%s'", p_name(kx->p)); )
sendchallenge(kx, b, kxc->c, kxc->hc);
buf_init(&bb, buf_i, sizeof(buf_i));
- G_TORAW(gg, &bb, kxc->r);
+ G_TORAW(kx->kpriv->g, &bb, kxc->r);
buf_flip(&bb);
ks_encrypt(kxc->ks, MSG_KEYEXCH | KX_REPLY, &bb, b);
if (kxc->f & KXF_TIMER)
sel_rmtimer(&kxc->t);
gettimeofday(&tv, 0);
- tv.tv_sec += T_RETRY;
+ rs_time(&kxc->rs, &tv, &tv);
sel_addtimer(&sel, &kxc->t, &tv, kxc_timer, kxc);
kxc->f |= KXF_TIMER;
}
static int doprechallenge(keyexch *kx, buf *b)
{
stats *st = p_stats(kx->p);
- ge *c = G_CREATE(gg);
+ ge *c = G_CREATE(kx->kpriv->g);
ghash *h;
/* --- Ensure that we're in a sensible state --- */
/* --- Unpack the packet --- */
- if (G_FROMBUF(gg, b, c) || BLEFT(b))
+ if (G_FROMBUF(kx->kpriv->g, b, c) || BLEFT(b))
goto bad;
IF_TRACING(T_KEYEXCH, IF_TRACING(T_CRYPTO, {
- trace(T_CRYPTO, "crypto: challenge = %s", gestr(gg, c));
+ trace(T_CRYPTO, "crypto: challenge = %s", gestr(kx->kpriv->g, c));
}))
/* --- Send out a full challenge by return --- */
b = p_txstart(kx->p, MSG_KEYEXCH | KX_CHAL);
- h = GH_INIT(algs.h);
+ h = GH_INIT(kx->kpriv->algs.h);
HASH_STRING(h, "tripe-cookie");
- hashge(h, c);
+ hashge(h, kx->kpriv->g, c);
sendchallenge(kx, b, c, GH_DONE(h, 0));
GH_DESTROY(h);
st->n_kxout++;
/* --- Done --- */
- G_DESTROY(gg, c);
+ G_DESTROY(kx->kpriv->g, c);
return (0);
bad:
- if (c) G_DESTROY(gg, c);
+ if (c) G_DESTROY(kx->kpriv->g, c);
return (-1);
}
static kxchal *respond(keyexch *kx, unsigned msg, buf *b)
{
- ge *c = G_CREATE(gg);
- ge *r = G_CREATE(gg);
- ge *cc = G_CREATE(gg);
+ group *g = kx->kpriv->g;
+ const algswitch *algs = &kx->kpriv->algs;
+ size_t ixsz = kx->kpriv->indexsz;
+ ge *c = G_CREATE(g);
+ ge *r = G_CREATE(g);
+ ge *cc = G_CREATE(g);
const octet *hc, *ck;
size_t x, y, z;
mp *cv = 0;
/* --- Unpack the packet --- */
- if (G_FROMBUF(gg, b, c) ||
- (hc = buf_get(b, algs.hashsz)) == 0 ||
- (ck = buf_get(b, indexsz)) == 0) {
+ if (G_FROMBUF(g, b, c) ||
+ (hc = buf_get(b, algs->hashsz)) == 0 ||
+ (ck = buf_get(b, ixsz)) == 0) {
a_warn("KX", "?PEER", kx->p, "invalid", "%s", pkname[msg], A_END);
goto bad;
}
IF_TRACING(T_KEYEXCH, IF_TRACING(T_CRYPTO, {
- trace(T_CRYPTO, "crypto: challenge = %s", gestr(gg, c));
- trace_block(T_CRYPTO, "crypto: cookie", hc, algs.hashsz);
- trace_block(T_CRYPTO, "crypto: check-value", ck, indexsz);
+ trace(T_CRYPTO, "crypto: challenge = %s", gestr(g, c));
+ trace_block(T_CRYPTO, "crypto: cookie", hc, algs->hashsz);
+ trace_block(T_CRYPTO, "crypto: check-value", ck, ixsz);
}))
/* --- Discard a packet with an invalid cookie --- */
- if (hc && memcmp(hc, kx->hc, algs.hashsz) != 0) {
+ if (hc && memcmp(hc, kx->hc, algs->hashsz) != 0) {
a_warn("KX", "?PEER", kx->p, "incorrect", "cookie", A_END);
goto bad;
}
*/
if ((kxc = kxc_bychal(kx, c)) != 0) {
- h = GH_INIT(algs.h);
+ h = GH_INIT(algs->h);
HASH_STRING(h, "tripe-check-hash");
- GH_HASH(h, ck, indexsz);
- ok = !memcmp(kxc->ck, GH_DONE(h, 0), algs.hashsz);
+ GH_HASH(h, ck, ixsz);
+ ok = !memcmp(kxc->ck, GH_DONE(h, 0), algs->hashsz);
GH_DESTROY(h);
if (!ok) goto badcheck;
} else {
/* --- Compute the reply, and check the magic --- */
- G_EXP(gg, r, c, kpriv);
- cv = mpunmask(MP_NEW, ck, indexsz,
- hashcheck(kx->kpub, kx->c, c, r), algs.hashsz);
+ G_EXP(g, r, c, kx->kpriv->kpriv);
+ cv = mpunmask(MP_NEW, ck, ixsz, algs->mgf,
+ hashcheck(kx, kx->kpub->kpub, kx->c, c, r),
+ algs->hashsz);
IF_TRACING(T_KEYEXCH, IF_TRACING(T_CRYPTO, {
- trace(T_CRYPTO, "crypto: computed reply = %s", gestr(gg, r));
+ trace(T_CRYPTO, "crypto: computed reply = %s", gestr(g, r));
trace(T_CRYPTO, "crypto: recovered log = %s", mpstr(cv));
}))
- if (MP_CMP(cv, >, gg->r) ||
- (G_EXP(gg, cc, gg->g, cv), !G_EQ(gg, c, cc)))
+ if (MP_CMP(cv, >, g->r) ||
+ (G_EXP(g, cc, g->g, cv),
+ !G_EQ(g, c, cc)))
goto badcheck;
/* --- Fill in a new challenge block --- */
kxc = kxc_new(kx);
- G_COPY(gg, kxc->c, c);
- G_COPY(gg, kxc->r, r);
+ G_COPY(g, kxc->c, c);
+ G_COPY(g, kxc->r, r);
- h = GH_INIT(algs.h);
- HASH_STRING(h, "tripe-check-hash");
- GH_HASH(h, ck, indexsz);
- GH_DONE(h, kxc->ck);
- GH_DESTROY(h);
+ h = GH_INIT(algs->h); HASH_STRING(h, "tripe-check-hash");
+ GH_HASH(h, ck, ixsz);
+ GH_DONE(h, kxc->ck); GH_DESTROY(h);
- h = GH_INIT(algs.h);
- HASH_STRING(h, "tripe-cookie");
- hashge(h, kxc->c);
- GH_DONE(h, kxc->hc);
- GH_DESTROY(h);
+ h = GH_INIT(algs->h); HASH_STRING(h, "tripe-cookie");
+ hashge(h, g, kxc->c);
+ GH_DONE(h, kxc->hc); GH_DESTROY(h);
IF_TRACING(T_KEYEXCH, IF_TRACING(T_CRYPTO, {
- trace_block(T_CRYPTO, "crypto: computed cookie", kxc->hc, algs.hashsz);
+ trace_block(T_CRYPTO, "crypto: computed cookie",
+ kxc->hc, algs->hashsz);
}))
/* --- Work out the shared key --- */
- G_EXP(gg, r, c, kx->alpha);
+ G_EXP(g, r, c, kx->alpha);
IF_TRACING(T_KEYEXCH, IF_TRACING(T_CRYPTO, {
- trace(T_CRYPTO, "crypto: shared secret = %s", gestr(gg, r));
+ trace(T_CRYPTO, "crypto: shared secret = %s", gestr(g, r));
}))
/* --- Compute the switch messages --- */
- h = GH_INIT(algs.h); HASH_STRING(h, "tripe-switch-request");
- hashge(h, kx->c); hashge(h, kxc->c);
+ h = GH_INIT(algs->h); HASH_STRING(h, "tripe-switch-request");
+ hashge(h, g, kx->c); hashge(h, g, kxc->c);
GH_DONE(h, kxc->hswrq_out); GH_DESTROY(h);
- h = GH_INIT(algs.h); HASH_STRING(h, "tripe-switch-confirm");
- hashge(h, kx->c); hashge(h, kxc->c);
+ h = GH_INIT(algs->h); HASH_STRING(h, "tripe-switch-confirm");
+ hashge(h, g, kx->c); hashge(h, g, kxc->c);
GH_DONE(h, kxc->hswok_out); GH_DESTROY(h);
- h = GH_INIT(algs.h); HASH_STRING(h, "tripe-switch-request");
- hashge(h, kxc->c); hashge(h, kx->c);
+ h = GH_INIT(algs->h); HASH_STRING(h, "tripe-switch-request");
+ hashge(h, g, kxc->c); hashge(h, g, kx->c);
GH_DONE(h, kxc->hswrq_in); GH_DESTROY(h);
- h = GH_INIT(algs.h); HASH_STRING(h, "tripe-switch-confirm");
- hashge(h, kxc->c); hashge(h, kx->c);
+ h = GH_INIT(algs->h); HASH_STRING(h, "tripe-switch-confirm");
+ hashge(h, g, kxc->c); hashge(h, g, kx->c);
GH_DONE(h, kxc->hswok_in); GH_DESTROY(h);
IF_TRACING(T_KEYEXCH, IF_TRACING(T_CRYPTO, {
trace_block(T_CRYPTO, "crypto: outbound switch request",
- kxc->hswrq_out, algs.hashsz);
+ kxc->hswrq_out, algs->hashsz);
trace_block(T_CRYPTO, "crypto: outbound switch confirm",
- kxc->hswok_out, algs.hashsz);
+ kxc->hswok_out, algs->hashsz);
trace_block(T_CRYPTO, "crypto: inbound switch request",
- kxc->hswrq_in, algs.hashsz);
+ kxc->hswrq_in, algs->hashsz);
trace_block(T_CRYPTO, "crypto: inbound switch confirm",
- kxc->hswok_in, algs.hashsz);
+ kxc->hswok_in, algs->hashsz);
}))
/* --- Create a new symmetric keyset --- */
buf_init(&bb, buf_o, sizeof(buf_o));
- G_TOBUF(gg, &bb, kx->c); x = BLEN(&bb);
- G_TOBUF(gg, &bb, kxc->c); y = BLEN(&bb);
- G_TOBUF(gg, &bb, r); z = BLEN(&bb);
+ G_TOBUF(g, &bb, kx->c); x = BLEN(&bb);
+ G_TOBUF(g, &bb, kxc->c); y = BLEN(&bb);
+ G_TOBUF(g, &bb, r); z = BLEN(&bb);
assert(BOK(&bb));
kxc->ks = ks_gen(BBASE(&bb), x, y, z, kx->p);
}
- G_DESTROY(gg, c);
- G_DESTROY(gg, cc);
- G_DESTROY(gg, r);
+ G_DESTROY(g, c);
+ G_DESTROY(g, cc);
+ G_DESTROY(g, r);
mp_drop(cv);
return (kxc);
a_warn("KX", "?PEER", kx->p, "bad-expected-reply-log", A_END);
goto bad;
bad:
- G_DESTROY(gg, c);
- G_DESTROY(gg, cc);
- G_DESTROY(gg, r);
+ G_DESTROY(g, c);
+ G_DESTROY(g, cc);
+ G_DESTROY(g, r);
mp_drop(cv);
return (0);
}
kxchal *kxc;
buf bb;
stats *st = p_stats(kx->p);
+ struct timeval tv;
buf *b;
switch (kx->s) {
T( trace(T_KEYEXCH, "keyexch: sending prechallenge to `%s'",
p_name(kx->p)); )
b = p_txstart(kx->p, MSG_KEYEXCH | KX_PRECHAL);
- G_TOBUF(gg, b, kx->c);
+ G_TOBUF(kx->kpriv->g, b, kx->c);
break;
case KXS_COMMIT:
T( trace(T_KEYEXCH, "keyexch: sending switch request to `%s'",
p_name(kx->p)); )
kxc = kx->r[0];
b = p_txstart(kx->p, MSG_KEYEXCH | KX_SWITCH);
- buf_put(b, kx->hc, algs.hashsz);
- buf_put(b, kxc->hc, algs.hashsz);
+ buf_put(b, kx->hc, kx->kpriv->algs.hashsz);
+ buf_put(b, kxc->hc, kx->kpriv->algs.hashsz);
buf_init(&bb, buf_i, sizeof(buf_i));
- G_TORAW(gg, &bb, kxc->r);
- buf_put(&bb, kxc->hswrq_out, algs.hashsz);
+ G_TORAW(kx->kpriv->g, &bb, kxc->r);
+ buf_put(&bb, kxc->hswrq_out, kx->kpriv->algs.hashsz);
buf_flip(&bb);
ks_encrypt(kxc->ks, MSG_KEYEXCH | KX_SWITCH, &bb, b);
break;
kxc = kx->r[0];
b = p_txstart(kx->p, MSG_KEYEXCH | KX_SWITCHOK);
buf_init(&bb, buf_i, sizeof(buf_i));
- buf_put(&bb, kxc->hswok_out, algs.hashsz);
+ buf_put(&bb, kxc->hswok_out, kx->kpriv->algs.hashsz);
buf_flip(&bb);
ks_encrypt(kxc->ks, MSG_KEYEXCH | KX_SWITCHOK, &bb, b);
break;
p_txend(kx->p);
}
- if (kx->s < KXS_SWITCH)
- settimer(kx, time(0) + T_RETRY);
+ if (kx->s < KXS_SWITCH) {
+ rs_time(&kx->rs, &tv, 0);
+ settimer(kx, &tv);
+ }
}
/* --- @decryptrest@ --- *
a_warn("KX", "?PEER", kx->p, "decrypt-failed", "%s", pkname[msg], A_END);
return (-1);
}
+ if (!BOK(&bb)) return (-1);
buf_init(b, BBASE(&bb), BLEN(&bb));
return (0);
}
static int checkresponse(keyexch *kx, unsigned msg, buf *b)
{
- ge *r = G_CREATE(gg);
+ group *g = kx->kpriv->g;
+ ge *r = G_CREATE(g);
- if (G_FROMRAW(gg, b, r)) {
+ if (G_FROMRAW(g, b, r)) {
a_warn("KX", "?PEER", kx->p, "invalid", "%s", pkname[msg], A_END);
goto bad;
}
IF_TRACING(T_KEYEXCH, IF_TRACING(T_CRYPTO, {
- trace(T_CRYPTO, "crypto: reply = %s", gestr(gg, r));
+ trace(T_CRYPTO, "crypto: reply = %s", gestr(g, r));
}))
- if (!G_EQ(gg, r, kx->rx)) {
+ if (!G_EQ(g, r, kx->rx)) {
a_warn("KX", "?PEER", kx->p, "incorrect", "response", A_END);
goto bad;
}
- G_DESTROY(gg, r);
+ G_DESTROY(g, r);
return (0);
bad:
- G_DESTROY(gg, r);
+ G_DESTROY(g, r);
return (-1);
}
static void kxfinish(keyexch *kx)
{
kxchal *kxc = kx->r[0];
+ struct timeval now, tv;
+
ks_activate(kxc->ks);
- settimer(kx, ks_tregen(kxc->ks));
+ gettimeofday(&now, 0);
+ f2tv(&tv, wobble(T_REGEN));
+ TV_ADD(&tv, &now, &tv);
+ settimer(kx, &tv);
kx->s = KXS_SWITCH;
a_notify("KXDONE", "?PEER", kx->p, A_END);
p_stats(kx->p)->t_kx = time(0);
static int doswitch(keyexch *kx, buf *b)
{
+ size_t hsz = kx->kpriv->algs.hashsz;
const octet *hc_in, *hc_out, *hswrq;
kxchal *kxc;
- if ((hc_in = buf_get(b, algs.hashsz)) == 0 ||
- (hc_out = buf_get(b, algs.hashsz)) == 0) {
+ if ((hc_in = buf_get(b, hsz)) == 0 ||
+ (hc_out = buf_get(b, hsz)) == 0) {
a_warn("KX", "?PEER", kx->p, "invalid", "switch-rq", A_END);
goto bad;
}
IF_TRACING(T_KEYEXCH, IF_TRACING(T_CRYPTO, {
- trace_block(T_CRYPTO, "crypto: challenge", hc_in, algs.hashsz);
- trace_block(T_CRYPTO, "crypto: cookie", hc_out, algs.hashsz);
+ trace_block(T_CRYPTO, "crypto: challenge", hc_in, hsz);
+ trace_block(T_CRYPTO, "crypto: cookie", hc_out, hsz);
}))
if ((kxc = kxc_byhc(kx, hc_in)) == 0 ||
- memcmp(hc_out, kx->hc, algs.hashsz) != 0) {
+ memcmp(hc_out, kx->hc, hsz) != 0) {
a_warn("KX", "?PEER", kx->p, "incorrect", "switch-rq", A_END);
goto bad;
}
if (decryptrest(kx, kxc, KX_SWITCH, b) ||
checkresponse(kx, KX_SWITCH, b))
goto bad;
- if ((hswrq = buf_get(b, algs.hashsz)) == 0 || BLEFT(b)) {
+ if ((hswrq = buf_get(b, hsz)) == 0 || BLEFT(b)) {
a_warn("KX", "?PEER", kx->p, "invalid", "switch-rq", A_END);
goto bad;
}
IF_TRACING(T_KEYEXCH, {
- trace_block(T_CRYPTO, "crypto: switch request hash", hswrq, algs.hashsz);
+ trace_block(T_CRYPTO, "crypto: switch request hash", hswrq, hsz);
})
- if (memcmp(hswrq, kxc->hswrq_in, algs.hashsz) != 0) {
+ if (memcmp(hswrq, kxc->hswrq_in, hsz) != 0) {
a_warn("KX", "?PEER", kx->p, "incorrect", "switch-rq", A_END);
goto bad;
}
static int doswitchok(keyexch *kx, buf *b)
{
+ size_t hsz = kx->kpriv->algs.hashsz;
const octet *hswok;
kxchal *kxc;
buf bb;
buf_init(&bb, buf_o, sizeof(buf_o));
if (decryptrest(kx, kxc, KX_SWITCHOK, b))
goto bad;
- if ((hswok = buf_get(b, algs.hashsz)) == 0 || BLEFT(b)) {
+ if ((hswok = buf_get(b, hsz)) == 0 || BLEFT(b)) {
a_warn("KX", "?PEER", kx->p, "invalid", "switch-ok", A_END);
goto bad;
}
IF_TRACING(T_KEYEXCH, {
trace_block(T_CRYPTO, "crypto: switch confirmation hash",
- hswok, algs.hashsz);
+ hswok, hsz);
})
- if (memcmp(hswok, kxc->hswok_in, algs.hashsz) != 0) {
+ if (memcmp(hswok, kxc->hswok_in, hsz) != 0) {
a_warn("KX", "?PEER", kx->p, "incorrect", "switch-ok", A_END);
goto bad;
}
for (i = 0; i < kx->nr; i++)
kxc_destroy(kx->r[i]);
mp_drop(kx->alpha);
- G_DESTROY(gg, kx->c);
- G_DESTROY(gg, kx->rx);
+ G_DESTROY(kx->kpriv->g, kx->c);
+ G_DESTROY(kx->kpriv->g, kx->rx);
kx->t_valid = 0;
kx->f |= KXF_DEAD;
kx->f &= ~KXF_TIMER;
static void start(keyexch *kx, time_t now)
{
+ algswitch *algs = &kx->kpriv->algs;
+ group *g = kx->kpriv->g;
ghash *h;
assert(kx->f & KXF_DEAD);
kx->f &= ~(KXF_DEAD | KXF_CORK);
kx->nr = 0;
- kx->alpha = mprand_range(MP_NEW, gg->r, &rand_global, 0);
- kx->c = G_CREATE(gg); G_EXP(gg, kx->c, gg->g, kx->alpha);
- kx->rx = G_CREATE(gg); G_EXP(gg, kx->rx, kx->kpub, kx->alpha);
+ kx->alpha = mprand_range(MP_NEW, g->r, &rand_global, 0);
+ kx->c = G_CREATE(g); G_EXP(g, kx->c, g->g, kx->alpha);
+ kx->rx = G_CREATE(g); G_EXP(g, kx->rx, kx->kpub->kpub, kx->alpha);
kx->s = KXS_CHAL;
kx->t_valid = now + T_VALID;
- h = GH_INIT(algs.h);
+ h = GH_INIT(algs->h);
HASH_STRING(h, "tripe-cookie");
- hashge(h, kx->c);
+ hashge(h, g, kx->c);
GH_DONE(h, kx->hc);
GH_DESTROY(h);
trace(T_KEYEXCH, "keyexch: creating new challenge");
IF_TRACING(T_CRYPTO, {
trace(T_CRYPTO, "crypto: secret = %s", mpstr(kx->alpha));
- trace(T_CRYPTO, "crypto: challenge = %s", gestr(gg, kx->c));
- trace(T_CRYPTO, "crypto: expected response = %s", gestr(gg, kx->rx));
- trace_block(T_CRYPTO, "crypto: challenge cookie", kx->hc, algs.hashsz);
+ trace(T_CRYPTO, "crypto: challenge = %s", gestr(g, kx->c));
+ trace(T_CRYPTO, "crypto: expected response = %s", gestr(g, kx->rx));
+ trace_block(T_CRYPTO, "crypto: challenge cookie",
+ kx->hc, algs->hashsz);
})
})
}
static int checkpub(keyexch *kx)
{
time_t now;
+ unsigned f = 0;
+
if (kx->f & KXF_DEAD)
return (-1);
now = time(0);
- if (KEY_EXPIRED(now, kx->texp_kpub)) {
+ if (KEY_EXPIRED(now, kx->kpriv->t_exp)) f |= 1;
+ if (KEY_EXPIRED(now, kx->kpub->t_exp)) f |= 2;
+ if (f) {
stop(kx);
- a_warn("KX", "?PEER", kx->p, "public-key-expired", A_END);
- G_COPY(gg, kx->kpub, gg->i);
+ if (f & 1) a_warn("KX", "?PEER", kx->p, "private-key-expired", A_END);
+ if (f & 2) a_warn("KX", "?PEER", kx->p, "public-key-expired", A_END);
kx->f &= ~KXF_PUBKEY;
return (-1);
}
void kx_message(keyexch *kx, unsigned msg, buf *b)
{
- time_t now = time(0);
+ struct timeval now, tv;
stats *st = p_stats(kx->p);
size_t sz = BSZ(b);
int rc;
+ gettimeofday(&now, 0);
+ rs_reset(&kx->rs);
if (kx->f & KXF_CORK) {
- start(kx, now);
- settimer(kx, now + T_RETRY);
+ start(kx, now.tv_sec);
+ rs_time(&kx->rs, &tv, &now);
+ settimer(kx, &tv);
a_notify("KXSTART", A_END);
}
if (checkpub(kx))
return;
- if (!VALIDP(kx, now)) {
+ if (!VALIDP(kx, now.tv_sec)) {
stop(kx);
- start(kx, now);
+ start(kx, now.tv_sec);
}
T( trace(T_KEYEXCH, "keyexch: processing %s packet from `%s'",
msg < KX_NMSG ? pkname[msg] : "unknown", p_name(kx->p)); )
void kx_free(keyexch *kx)
{
stop(kx);
- G_DESTROY(gg, kx->kpub);
+ km_unref(kx->kpub);
+ km_unref(kx->kpriv);
}
/* --- @kx_newkeys@ --- *
void kx_newkeys(keyexch *kx)
{
- if (km_getpubkey(p_name(kx->p), kx->kpub, &kx->texp_kpub))
- return;
+ kdata *kpriv, *kpub;
+ unsigned i;
+ int switchp;
+ time_t now = time(0);
+
+ T( trace(T_KEYEXCH, "keyexch: checking new keys for `%s'",
+ p_name(kx->p)); )
+
+ /* --- Find out whether we can use new keys --- *
+ *
+ * Try each available combination of new and old, public and private,
+ * except both old (which is status quo anyway). The selection is encoded
+ * in @i@, with bit 0 for the private key and bit 1 for public key; a set
+ * bit means to use the old value, and a clear bit means to use the new
+ * one.
+ *
+ * This means that we currently prefer `old private and new public' over
+ * `new private and old public'. I'm not sure which way round this should
+ * actually be.
+ */
+
+ for (i = 0; i < 3; i++) {
+
+ /* --- Select the keys we're going to examine --- *
+ *
+ * If we're meant to have a new key and don't, then skip this
+ * combination.
+ */
+
+ T( trace(T_KEYEXCH, "keyexch: checking %s private, %s public",
+ i & 1 ? "old" : "new", i & 2 ? "old" : "new"); )
+
+ if (i & 1) kpriv = kx->kpriv;
+ else if (kx->kpriv->kn->kd != kx->kpriv) kpriv = kx->kpriv->kn->kd;
+ else {
+ T( trace(T_KEYEXCH, "keyexch: private key unchanged, skipping"); )
+ continue;
+ }
+
+ if (i & 2) kpub = kx->kpub;
+ else if (kx->kpub->kn->kd != kx->kpub) kpub = kx->kpub->kn->kd;
+ else {
+ T( trace(T_KEYEXCH, "keyexch: public key unchanged, skipping"); )
+ continue;
+ }
+
+ /* --- Skip if either key is expired --- *
+ *
+ * We're not going to get far with expired keys, and this simplifies the
+ * logic below.
+ */
+
+ if (KEY_EXPIRED(now, kx->kpriv->t_exp) ||
+ KEY_EXPIRED(now, kx->kpub->t_exp)) {
+ T( trace(T_KEYEXCH, "keyexch: %s expired, skipping",
+ !KEY_EXPIRED(now, kx->kpriv->t_exp) ? "public key" :
+ !KEY_EXPIRED(now, kx->kpub->t_exp) ? "private key" :
+ "both keys"); )
+ continue;
+ }
+
+ /* --- If the groups don't match then we can't use this pair --- */
+
+ if (!km_samealgsp(kpriv, kpub)) {
+ T( trace(T_KEYEXCH, "keyexch: peer `%s' group mismatch; "
+ "%s priv `%s' and %s pub `%s'", p_name(kx->p),
+ i & 1 ? "old" : "new", km_tag(kx->kpriv),
+ i & 2 ? "old" : "new", km_tag(kx->kpub)); )
+ continue;
+ }
+ goto newkeys;
+ }
+ T( trace(T_KEYEXCH, "keyexch: peer `%s' continuing with old keys",
+ p_name(kx->p)); )
+ return;
+
+ /* --- We've chosen new keys --- *
+ *
+ * Switch the new ones into place. Neither of the keys we're switching to
+ * is expired (we checked that above), so we should just crank everything
+ * up.
+ *
+ * A complication arises: we don't really want to force a new key exchange
+ * unless we have to. If the group is unchanged, and we're currently
+ * running OK, then we should just let things lie.
+ */
+
+newkeys:
+ switchp = ((kx->f & KXF_DEAD) ||
+ kx->s != KXS_SWITCH ||
+ !group_samep(kx->kpriv->g, kpriv->g));
+
+ T( trace(T_KEYEXCH, "keyexch: peer `%s' adopting "
+ "%s priv `%s' and %s pub `%s'; %sforcing exchange", p_name(kx->p),
+ i & 1 ? "old" : "new", km_tag(kx->kpriv),
+ i & 2 ? "old" : "new", km_tag(kx->kpub),
+ switchp ? "" : "not "); )
+
+ if (switchp) stop(kx);
+ km_ref(kpriv); km_unref(kx->kpriv); kx->kpriv = kpriv;
+ km_ref(kpub); km_unref(kx->kpub); kx->kpub = kpub;
kx->f |= KXF_PUBKEY;
- if ((kx->f & KXF_DEAD) || kx->s != KXS_SWITCH) {
+ if (switchp) {
T( trace(T_KEYEXCH, "keyexch: restarting key negotiation with `%s'",
p_name(kx->p)); )
- stop(kx);
start(kx, time(0));
resend(kx);
}
int kx_init(keyexch *kx, peer *p, keyset **ks, unsigned f)
{
+ if ((kx->kpriv = km_findpriv(p_privtag(p))) == 0) goto fail_0;
+ if ((kx->kpub = km_findpub(p_tag(p))) == 0) goto fail_1;
+ if (!group_samep(kx->kpriv->g, kx->kpub->g)) {
+ a_warn("KX", "?PEER", kx->p, "group-mismatch",
+ "local-private-key", "%s", p_privtag(p),
+ "peer-public-key", "%s", p_tag(p),
+ A_END);
+ goto fail_2;
+ }
+
kx->ks = ks;
kx->p = p;
- kx->kpub = G_CREATE(gg);
- if (km_getpubkey(p_name(p), kx->kpub, &kx->texp_kpub)) {
- G_DESTROY(gg, kx->kpub);
- return (-1);
- }
kx->f = KXF_DEAD | KXF_PUBKEY | f;
+ rs_reset(&kx->rs);
if (!(kx->f & KXF_CORK)) {
start(kx, time(0));
resend(kx);
/* Don't notify here: the ADD message hasn't gone out yet. */
}
return (0);
+
+fail_2:
+ km_unref(kx->kpub);
+fail_1:
+ km_unref(kx->kpriv);
+fail_0:
+ return (-1);
}
/*----- That's all, folks -------------------------------------------------*/
~mdw / tripe / blobdiff