*
* This file is part of Trivial IP Encryption (TrIPE).
*
- * TrIPE is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
+ * TrIPE is free software: you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 3 of the License, or (at your
+ * option) any later version.
*
- * TrIPE is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
+ * TrIPE is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * for more details.
*
* You should have received a copy of the GNU General Public License
- * along with TrIPE; if not, write to the Free Software Foundation,
- * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ * along with TrIPE. If not, see <https://www.gnu.org/licenses/>.
*/
/*----- Header files ------------------------------------------------------*/
/* --- @hashge@ --- *
*
* Arguments: @ghash *h@ = pointer to hash context
- * @ge *x@ = pointer to group element
+ * @const dhgrp *g@ = pointer to group
+ * @const dhge *Y@ = pointer to group element
*
* Returns: ---
*
* @buf_t@.
*/
-static void hashge(ghash *h, ge *x)
+static void hashge(ghash *h, const dhgrp *g, const dhge *Y)
{
buf b;
+
buf_init(&b, buf_t, sizeof(buf_t));
- G_TOBUF(gg, &b, x);
+ g->ops->stge(g, &b, Y, DHFMT_HASH);
assert(BOK(&b));
GH_HASH(h, BBASE(&b), BLEN(&b));
}
/* --- @mpmask@ --- *
*
* Arguments: @buf *b@ = output buffer
- * @mp *x@ = the plaintext integer
+ * @const dhgrp *g@ = the group
+ * @const dhsc *x@ = the plaintext scalar
* @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
*
- * Returns: Pointer to the output.
+ * Returns: ---
*
- * Use: Masks a multiprecision integer: returns %$x \xor H(k)$%, so
- * it's a random oracle thing rather than an encryption thing.
+ * Use: Masks a scalar: returns %$x \xor H(k)$%, so it's a random
+ * oracle thing rather than an encryption thing. Breaks the
+ * output buffer on error.
*/
-static octet *mpmask(buf *b, mp *x, size_t n, const octet *k, size_t ksz)
+static void mpmask(buf *b, const dhgrp *g, const dhsc *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);
+ if ((p = buf_get(b, n)) == 0) return;
+ 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 scalar = %s", g->ops->scstr(g, x));
+ trace_block(T_CRYPTO, "crypto: masking key", k, ksz);
}))
- mp_storeb(x, buf_t, n);
+ if (g->ops->stsc(g, buf_t, n, x)) { buf_break(b); return; }
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: scalar plaintext", buf_t, n);
+ trace_block(T_CRYPTO, "crypto: masked ciphertext", p, n);
}))
GC_DESTROY(mgf);
- return (p);
}
/* --- @mpunmask@ --- *
*
- * Arguments: @mp *d@ = the output integer
+ * Arguments: @const dhgrp *g@ = the group
* @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
*
- * Returns: The decrypted integer, or null.
+ * Returns: The decrypted scalar, or null.
*
- * Use: Unmasks a multiprecision integer.
+ * Use: Unmasks a scalar.
*/
-static mp *mpunmask(mp *d, const octet *p, size_t n,
- const octet *k, size_t ksz)
+static dhsc *mpunmask(const dhgrp *g, const octet *p, size_t n,
+ const gccipher *mgfc, const octet *k, size_t ksz)
{
gcipher *mgf;
+ dhsc *x;
- 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);
+ x = g->ops->ldsc(g, 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: scalar plaintext", buf_t, n);
+ trace(T_CRYPTO, "crypto: unmasked scalar = %s",
+ x ? g->ops->scstr(g, x) : "<failed>");
}))
GC_DESTROY(mgf);
- return (d);
+ return (x);
}
/* --- @hashcheck@ --- *
*
- * Arguments: @ge *kpub@ = sender's public key
- * @ge *cc@ = receiver's challenge
- * @ge *c@ = sender's challenge
- * @ge *y@ = reply to sender's challenge
+ * Arguments: @keyexch *kx@ = pointer to key-exchange block
+ * @const dhge *K@ = sender's public key
+ * @const dhge *CC@ = receiver's challenge
+ * @const dhge *C@ = sender's challenge
+ * @const dhge *Y@ = reply to sender's challenge
*
* Returns: Pointer to the hash value (in @buf_t@)
*
* indices to prove the validity of challenges. This computes
* the masking key used in challenge check values. This is
* really the heart of the whole thing, since it ensures that
- * the index can be recovered from the history of hashing
+ * the scalar can be recovered from the history of hashing
* queries, which gives us (a) a proof that the authentication
* process is zero-knowledge, and (b) a proof that the whole
* key-exchange is deniable.
*/
-static const octet *hashcheck(ge *kpub, ge *cc, ge *c, ge *y)
+static const octet *hashcheck(keyexch *kx, const dhge *K,
+ const dhge *CC, const dhge *C, const dhge *Y)
{
- ghash *h = GH_INIT(algs.h);
+ ghash *h = GH_INIT(kx->kpriv->algs.h);
+ const dhgrp *g = kx->kpriv->grp;
HASH_STRING(h, "tripe-expected-reply");
- hashge(h, kpub);
- hashge(h, cc);
- hashge(h, c);
- hashge(h, y);
+ hashge(h, g, K);
+ 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", g->ops->gestr(g, K));
+ trace(T_CRYPTO, "crypto: receiver challenge = %s", g->ops->gestr(g, CC));
+ trace(T_CRYPTO, "crypto: sender challenge = %s", g->ops->gestr(g, C));
+ trace(T_CRYPTO, "crypto: sender reply = %s", g->ops->gestr(g, Y));
+ trace_block(T_CRYPTO, "crypto: hash output", buf_t, kx->kpriv->algs.hashsz);
}))
GH_DESTROY(h);
return (buf_t);
*
* Arguments: @keyexch *kx@ = pointer to key exchange block
* @buf *b@ = output buffer for challenge
- * @ge *c@ = peer's actual challenge
+ * @const dhge *C@ = peer's actual challenge
* @const octet *hc@ = peer's challenge cookie
*
* Returns: ---
* Use: Writes a full challenge to the message buffer.
*/
-static void sendchallenge(keyexch *kx, buf *b, ge *c, const octet *hc)
+static void sendchallenge(keyexch *kx, buf *b,
+ const dhge *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);
+ const dhgrp *g = kx->kpriv->grp;
+ g->ops->stge(g, b, kx->C, DHFMT_VAR);
+ buf_put(b, hc, kx->kpriv->algs.hashsz);
+ mpmask(b, g, kx->a, g->scsz, kx->kpriv->algs.mgf,
+ hashcheck(kx, kx->kpriv->K, C, kx->C, kx->RX),
+ kx->kpriv->algs.hashsz);
}
/* --- @timer@ --- *
static void kxc_destroy(kxchal *kxc)
{
+ const dhgrp *g = kxc->kx->kpriv->grp;
if (kxc->f & KXF_TIMER)
sel_rmtimer(&kxc->t);
- G_DESTROY(gg, kxc->c);
- G_DESTROY(gg, kxc->r);
+ g->ops->freege(g, kxc->C);
+ g->ops->freege(g, kxc->R);
ks_drop(kxc->ks);
DESTROY(kxc);
}
* Returns: A pointer to the challenge block.
*
* Use: Returns a pointer to a new challenge block to fill in.
+ * In particular, the @c@ and @r@ members are left
+ * uninitialized.
*/
static kxchal *kxc_new(keyexch *kx)
/* --- Fill in the new structure --- */
kxc = CREATE(kxchal);
- kxc->c = G_CREATE(gg);
- kxc->r = G_CREATE(gg);
kxc->ks = 0;
kxc->kx = kx;
kxc->f = 0;
/* --- @kxc_bychal@ --- *
*
* Arguments: @keyexch *kx@ = pointer to key exchange block
- * @ge *c@ = challenge from remote host
+ * @const dhge *C@ = challenge from remote host
*
* Returns: Pointer to the challenge block, or null.
*
* Use: Finds a challenge block, given its challenge.
*/
-static kxchal *kxc_bychal(keyexch *kx, ge *c)
+static kxchal *kxc_bychal(keyexch *kx, const dhge *C)
{
+ const dhgrp *g = kx->kpriv->grp;
unsigned i;
for (i = 0; i < kx->nr; i++) {
- if (G_EQ(gg, c, kx->r[i]->c))
+ if (g->ops->eq(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);
{
stats *st = p_stats(kx->p);
buf *b = p_txstart(kx->p, MSG_KEYEXCH | KX_REPLY);
+ const dhgrp *g = kx->kpriv->grp;
struct timeval tv;
buf bb;
/* --- Build the reply packet --- */
T( trace(T_KEYEXCH, "keyexch: sending reply to `%s'", p_name(kx->p)); )
- sendchallenge(kx, b, kxc->c, kxc->hc);
+ sendchallenge(kx, b, kxc->C, kxc->hc);
buf_init(&bb, buf_i, sizeof(buf_i));
- G_TORAW(gg, &bb, kxc->r);
+ g->ops->stge(g, &bb, kxc->R, DHFMT_STD);
buf_flip(&bb);
ks_encrypt(kxc->ks, MSG_KEYEXCH | KX_REPLY, &bb, b);
static int doprechallenge(keyexch *kx, buf *b)
{
stats *st = p_stats(kx->p);
- ge *c = G_CREATE(gg);
+ const dhgrp *g = kx->kpriv->grp;
+ dhge *C = 0;
ghash *h;
/* --- Ensure that we're in a sensible state --- */
/* --- Unpack the packet --- */
- if (G_FROMBUF(gg, b, c) || BLEFT(b))
+ if ((C = g->ops->ldge(g, b, DHFMT_VAR)) == 0 || 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", g->ops->gestr(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);
- sendchallenge(kx, b, c, GH_DONE(h, 0));
+ hashge(h, g, C);
+ sendchallenge(kx, b, C, GH_DONE(h, 0));
GH_DESTROY(h);
st->n_kxout++;
st->sz_kxout += BLEN(b);
/* --- Done --- */
- G_DESTROY(gg, c);
+ g->ops->freege(g, C);
return (0);
bad:
- if (c) G_DESTROY(gg, c);
+ if (C) g->ops->freege(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);
+ const dhgrp *g = kx->kpriv->grp;
+ const algswitch *algs = &kx->kpriv->algs;
+ size_t ixsz = g->scsz;
+ dhge *C = 0;
+ dhge *R = 0;
+ dhge *CC = 0;
const octet *hc, *ck;
size_t x, y, z;
- mp *cv = 0;
+ dhsc *c = 0;
kxchal *kxc;
ghash *h = 0;
buf bb;
/* --- Unpack the packet --- */
- if (G_FROMBUF(gg, b, c) ||
- (hc = buf_get(b, algs.hashsz)) == 0 ||
- (ck = buf_get(b, indexsz)) == 0) {
+ if ((C = g->ops->ldge(g, b, DHFMT_VAR)) == 0 ||
+ (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", g->ops->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;
}
* This will also find a challenge block and, if necessary, populate it.
*/
- if ((kxc = kxc_bychal(kx, c)) != 0) {
- h = GH_INIT(algs.h);
+ if ((kxc = kxc_bychal(kx, C)) != 0) {
+ 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);
+ R = g->ops->mul(g, kx->kpriv->k, C);
+ if ((c = mpunmask(g, ck, ixsz, algs->mgf,
+ hashcheck(kx, kx->kpub->K, kx->C, C, R),
+ algs->hashsz)) == 0)
+ goto badcheck;
IF_TRACING(T_KEYEXCH, IF_TRACING(T_CRYPTO, {
- trace(T_CRYPTO, "crypto: computed reply = %s", gestr(gg, r));
- trace(T_CRYPTO, "crypto: recovered log = %s", mpstr(cv));
+ trace(T_CRYPTO, "crypto: computed reply = %s", g->ops->gestr(g, R));
+ trace(T_CRYPTO, "crypto: recovered log = %s", g->ops->scstr(g, c));
}))
- if (MP_CMP(cv, >, gg->r) ||
- (G_EXP(gg, cc, gg->g, cv), !G_EQ(gg, c, cc)))
- goto badcheck;
+ CC = g->ops->mul(g, c, 0);
+ if (!g->ops->eq(g, CC, C)) goto badcheck;
/* --- Fill in a new challenge block --- */
kxc = kxc_new(kx);
- G_COPY(gg, kxc->c, c);
- G_COPY(gg, kxc->r, r);
+ kxc->C = C; C = 0;
+ kxc->R = R; R = 0;
- 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);
+ R = g->ops->mul(g, kx->a, kxc->C);
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", g->ops->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->ops->stge(g, &bb, kx->C, DHFMT_HASH); x = BLEN(&bb);
+ g->ops->stge(g, &bb, kxc->C, DHFMT_HASH); y = BLEN(&bb);
+ g->ops->stge(g, &bb, R, DHFMT_HASH); 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);
- mp_drop(cv);
+ if (C) g->ops->freege(g, C);
+ if (CC) g->ops->freege(g, CC);
+ if (R) g->ops->freege(g, R);
+ if (c) g->ops->freesc(g, c);
return (kxc);
badcheck:
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);
- mp_drop(cv);
+ if (C) g->ops->freege(g, C);
+ if (CC) g->ops->freege(g, CC);
+ if (R) g->ops->freege(g, R);
+ if (c) g->ops->freesc(g, c);
return (0);
}
buf bb;
stats *st = p_stats(kx->p);
struct timeval tv;
+ const dhgrp *g = kx->kpriv->grp;
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->ops->stge(g, b, kx->C, DHFMT_VAR);
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->ops->stge(g, &bb, kxc->R, DHFMT_STD);
+ 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;
static int checkresponse(keyexch *kx, unsigned msg, buf *b)
{
- ge *r = G_CREATE(gg);
+ const dhgrp *g = kx->kpriv->grp;
+ dhge *R;
- if (G_FROMRAW(gg, b, r)) {
+ if ((R = g->ops->ldge(g, b, DHFMT_STD)) == 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: reply = %s", gestr(gg, r));
+ trace(T_CRYPTO, "crypto: reply = %s", g->ops->gestr(g, R));
}))
- if (!G_EQ(gg, r, kx->rx)) {
+ if (!g->ops->eq(g, R, kx->RX)) {
a_warn("KX", "?PEER", kx->p, "incorrect", "response", A_END);
goto bad;
}
- G_DESTROY(gg, r);
+ g->ops->freege(g, R);
return (0);
bad:
- G_DESTROY(gg, r);
+ if (R) g->ops->freege(g, R);
return (-1);
}
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;
}
static void stop(keyexch *kx)
{
+ const dhgrp *g = kx->kpriv->grp;
unsigned i;
if (kx->f & KXF_DEAD)
sel_rmtimer(&kx->t);
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->ops->freesc(g, kx->a);
+ g->ops->freege(g, kx->C);
+ g->ops->freege(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;
+ const dhgrp *g = kx->kpriv->grp;
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->a = g->ops->randsc(g);
+ kx->C = g->ops->mul(g, kx->a, 0);
+ kx->RX = g->ops->mul(g, kx->a, kx->kpub->K);
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);
IF_TRACING(T_KEYEXCH, {
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: secret = %s", g->ops->scstr(g, kx->a));
+ trace(T_CRYPTO, "crypto: challenge = %s", g->ops->gestr(g, kx->C));
+ trace(T_CRYPTO, "crypto: expected response = %s",
+ g->ops->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);
}
start(kx, now.tv_sec);
rs_time(&kx->rs, &tv, &now);
settimer(kx, &tv);
- a_notify("KXSTART", A_END);
+ a_notify("KXSTART", "?PEER", kx->p, A_END);
}
if (checkpub(kx))
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_tag(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 ||
+ kpriv->grp->ops != kx->kpriv->grp->ops ||
+ !kpriv->grp->ops->samegrpp(kpriv->grp, kx->kpriv->grp));
+
+ 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 (!km_samealgsp(kx->kpriv, kx->kpub)) {
+ a_warn("KX", "?PEER", 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_tag(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)) {
/* 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